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Master’s thesisPhysical Geography and Quaternary Geology, 45 Credits
Department of Physical Geography and Quaternary Geology
Local water resource assessment in Messinia, Greece
Karin Ekstedt
NKA 812013
Preface This Master’s thesis is Karin Ekstedt’s degree project in Physical Geography and Quaternary Geology at the Department of Physical Geography and Quaternary Geology, Stockholm University. The Master’s thesis comprises 45 credits (one and a half term of full-time studies). Supervisors have been Jerker Jarsjö and Steve Lyon at the Department of Physical Geography and Quaternary Geology, Stockholm University. Examiner has been Karin Holmgren at the Department of Physical Geography and Quaternary Geology, Stockholm University. The author is responsible for the contents of this thesis. Stockholm, 13 June 2013
Lars-Ove Westerberg Director of studies
Local water resource assessment in Messinia, Greece
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ABSTRACT Messinia is a region in Greece renowned for its rich nature, olive agriculture and water
availability. In the light of increasing anthropogenic and climatic pressure, this study assessed
local water resources in catchments in south western parts of the region. The main objectives
were to evaluate the balance between supply and demand, the sustainability of current water
consumption, capacity of further land use intensification and to review local water
management. The method was dual with both quantitative (water balance calculations and
linear modeling) and qualitative (interviews and a questionnaire survey) approaches.
It was confirmed that, on an annual basis, rainfall is comparatively high, there is a surplus of
water leaving the catchments and aquifers are “superfluous”. The climate however, brings
seasonal imbalance and notable shortages during summer that affect operation of local actors,
especially with agriculture and tourism being the principal water users. Unofficial sources
indicated that current consumption may not be sustainable, either because of over-exploitation
or climatic changes, but further studies are required to draw reliable conclusions. Modeling
showed the importance of land management, that unconsidered water consumption may
impact the water balance substantially but also that, while minimizing evapotranspiration,
there is capacity of intensification if water withdrawals are increased. Considering
accessibility, competitive interests and sustainability however, such development is not
necessarily feasible.
The municipal water management appeared to be well established and, given that measures
are taken concerning for example stakeholder integration and regulation of private and
agricultural consumption, there is capacity of handling increasing water stress. Finally,
stressing the crucial role of freshwater availability, the study highlighted the importance of
further hydrological research and thus the need for improved data quality, particularly
regarding river discharge.
ACKNOWLEDGEMENTS First of all, I would like to give big thanks to Jerker Jarsjö and Steve Lyon for more than great
support and supervision throughout the project. Big thanks go also to the NEO (see below)
station managers Nikos Kalivitis (up to July 2012) and Giorgos Maneas who have been really
helpful with a variety of issues. Konstantine Boulolis, agronomist in Gargaliani, also deserves
special thanks for all the valuable information and material provided; during the interview and
in later e-mail conversations. The support from Efstathia Zontanou at Nileas, with the
interview and with collecting questionnaires is likewise highly appreciated. I am grateful also
to Victoras Plevrakis for consultation and pictures and, together with Katerina Mazi and
Magdalini Zampouni, for translations to and from Greek. I furthermore want to mention
Göran Alm and Ingmar Borgström at the department who helped with lending a GPS and
providing data and material respectively. Thanks go also to Iris Claesson, at the Department
of Human Geography, for lending the Dictaphone. Finally, I want to thank TEMES for
providing the data, all that I interviewed and those who filled in the questionnaires and, of
course, family and friends that supported and encouraged me along the way. No report
without all of you.
Karin Ekstedt
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Local water resource assessment in Messinia, Greece
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TABLE OF CONTENTS
1. INTRODUCTION .............................................................................................................. 5
1.1 Study objectives ............................................................................................................ 5
1.2 Regional context ........................................................................................................... 5
2. DATA AND METHODS ................................................................................................. 10
2.1 Site description ............................................................................................................ 10
2.2 Data ............................................................................................................................. 12
2.3 Methods ....................................................................................................................... 16
3. RESULTS ......................................................................................................................... 22
3.1 The water balances ...................................................................................................... 22
3.2 ET of local vegetation and olive irrigation ................................................................. 23
3.3 Hypothetical land use intensification .......................................................................... 23
3.4 The interviews and questionnaires .............................................................................. 25
4. DISCUSSION ................................................................................................................... 31
4.1 Performance and uncertainty ...................................................................................... 32
4.2 The current state of local water resources ................................................................... 33
4.3 Local water management ............................................................................................ 37
4.4 Further studies ............................................................................................................. 39
5. SUMMARY AND CONCLUSIONS ............................................................................... 40
REFERENCES ..................................................................................................................... 41
APPENDIX A: STUDIES REVIEWED FOR ESTIMATING ET IN OLV AND NV ......... 46
APPENDIX B: THE QUESTIONNAIRE ............................................................................ 48
APPENDIX C: RESULTS OF MODEL 1 IN GIANOUZAGAS ........................................ 50
APPENDIX D: COMMENTS TO THE QUESTIONNAIRS ........................................................... 51
Karin Ekstedt
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Local water resource assessment in Messinia, Greece
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1. INTRODUCTION Freshwater availability is integral to all ecosystems and to all aspects in human societies,
economic as well as social. Therefore shortage can be a major constraint to development. In
the semi-arid Mediterranean region water resources are indeed limited, especially because of
the characteristic of seasonal imbalance in supply and demand that induces scarcity in the
summer months. This is also an area where climate change is projected to decrease water
availability further and where anthropogenic pressures are increasing through growing
population, tourism and irrigation demands (e.g. Tsagarakis, et al., 2003; IPCC, 2007a; b;
Trondalen, 2009).
Thus, understanding and monitoring the hydrological system and the anthropogenic influence
on it, is of high importance in both land and water management in this region (Sánchez-
Canales, et al., 2012). Research is fundamental on all scales and there is a need for
coordination and cooperation, between scientists and with stakeholders and policy makers.
(Cudennec, et al., 2007). From such motivation, this thesis looks at local water resources and
management in the area round Navarino Environmental Observatory (NEO), Greece, that is a
recently started cooperation between Stockholm University, the Academy of Athens and
TEMES S.A. The NEO is located at Costa Navarino, a luxury mixed-use resort being
developed by TEMES, and is meant to gather researchers from all over the world to offer a
platform for studies and knowledge exchange on Mediterranean environments.
1.1 Study objectives This study’s main objective is to evaluate the current state of water resources in three local
catchments in the area of NEO: the Sellas, Gianouzagas and Xerias rivers (see site
description). The study addresses both water availability and demands and an attempt is made
at both reviewing local water resources management and at assessing the situation and
opinion of local actors who deal with, and are depending on, the local water resources. More
specifically, it is investigated i) if there is shortage or surplus of water resources, ii) if current
levels of consumption are sustainable, iii) how local water management is set up and iv) if
management is sufficient to address increasing anthropogenic and climatic pressure in the
area. Also, to address current and future development, the capacity for hypothetical land use
intensification is simulated through simple linear modeling with emphasis on how such
intensification would affect local hydrological systems.
The overall method includes setting up the catchment water balances and modeling, but also
the gathering of information from local stakeholders through interviews and questionnaires
during a long-term stay on location. This dual approach offers a great opportunity of
characterizing local conditions and of identifying up-to-date key points. The hope is that the
thesis will provide an inclusive overview of the local hydrological system and make a starting
point for further water or other environmentally related studies in the area.
1.2 Regional context Costa Navarino is located in the western parts of Messinia in southwestern Peloponnese,
Greece (see site description), an area renowned for its rich nature and prosperous olive
agriculture in which human settlement reaches far back in time. The geography of the region
Karin Ekstedt
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was described in the 19th
century already and a number of physical studies have followed,
often in connection to archaeological investigations such as the “Minnesota Messina
Expedition” (McDonald and Rapp, 1972) and the “Pylos Regional Archaeological Project”
1991-1996 (Zangger, et al., 1997). Investigating local hydrology requires an understanding of
the regional context. Therefore the following sections offer a more detailed presentation of
principal regional parameters: climate, climate change, land use and water management.
1.2.1 Regional climate and water resources
For being under Mediterranean climate, weather in Messinia is relatively humid. Most
precipitation (P) in Greece is brought in by westerlies during winter and Messinia, being
situated on the west coast and on the windward side of the inland mountains, receives
relatively large amounts of rainfall. Annual P averages 1100 mm in this part of Greece but
varies over an elevation gradient starting at circa 800 mm at the coast, reaching 1000 mm
further uphill and around 1600 mm in the higher mountains (Loy and Wright, 1972; Ministry
of Development, 1997). This can be compared to an average of 652 mm over the entirety of
Greece (AQUASTAT, 2013) and to 350 mm round Athens and on the east coast - where the
land is shadowed by the Pindos mountain range extending north-south through the country
(Loy and Wright, 1972; Ministry of Development, 1997; Baltas, 2008).
Despite relatively large amounts, rainfall is still characterized by the Mediterranean
seasonality which is controlled by the north- and southward shift of the large-scale general
circulation systems. In winter, moist air and cyclonic depressions are brought in from the
Atlantic by the Subpolar jet stream and the westerly surface winds, while in summer, a
northward shift places the Bermuda-Azores subtropical high pressure system over the region.
Thus in summer, i.e. June-August, descending and warming air dominates, skies are clear and
P amounts are close to zero. About half the annual P falls in winter December-February,
mostly as rain, and the other half in autumn and spring. Summer thunderstorms are rare in the
region but do occasionally break the summer drought (Loy and Wright, 1972; Giorgi and
Lionello, 2008; Finne, et al., 2011).
Temperature (T) is also bound by the seasonality of the region. Mean T in Messinia is around
11°C in winter and 27°C in summer (Loy and Wright, 1972). Generally along the coasts in
Greece, mean minimum T in January-February is 5-10°C and mean maximum T in July-
August is 29-35°C. Sea breezes cool temperatures along the coasts during summer (HNMS,
2013) yet the intensive incoming solar radiation still causes high potential evapotranspiration
(PET) and atmospheric water demands that clearly exceed P (Fig. 1, after Loy and Wright,
1972). Hence, through the 5-6 months that make up the dry season, roughly April/May-
September/October, evapotranspiration (ET) is controlled by P in combination with soil
moisture and the system is clearly water-limited. Winters offer the opposite, P is rich and low
temperature gives low PET (e.g. Loy and Wright, 1972; Baltas, 2008; Ryu, et al., 2008;
HNMS, 2013).
Local water resource assessment in Messinia, Greece
7
P PET ET
1
2
3
200
150
100
50
Figure 1: Constructed graph (fictive numbers)
generalizing the typical annual interplay
between P, PET and ET under Mediterranean
conditions. At point 1 water surplus is ended
and PET exceeds P, ET draws on soil
moisture. At point 2 soil moisture is depleted
and there is a clear water deficit. At point 3 P
exceeds PET again and soil moisture is
recharged. After original water-balance
diagrams from the local area produced by Loy
and Wright (1972), p.39, Fig. 3-1.
Water availability in Greece follows the complex pattern of P and the country is split into
several smaller hydrological regions, ranging from those of intense deficiencies to those of
lasting surpluses (Sofios, et al., 2007; MEECC, 2010). As mentioned, P and therefore also
water resources, are generally richer in the western regions (Kerkides, et al., 1996) and
according to the Ministry of Development (1997), the district of Western Peloponnese has
ample surface- and ground water resources. Ground water flows in particular, are important
for water transport in this type of climate and landscape (Newman, et al., 1998; 2006). The
geological structure of Messinia, with limestone, sandstone and conglomerates, is favorable
for ground water generation and the mountain headwaters make up good catch basins (Loy
and Wright, 1972; García-Ruiz, et al., 2011). As a result, there are numerous springs at lower
altitudes and ground water can be easily extracted in wells. This is important for feeding the
extensive irrigation systems as well as for the drinking water supply, particularly in the
summer drought when most rivers run dry (Loy and Wright, 1972, MEECC, 2010).
1.2.2 Climate change and water resources
Numerous studies have reviewed the characteristics and impacts of climate change in the
Mediterranean region. It is identified as one of the primary “Hot-Spots” (Giorgi, 2006) and
most responsive and vulnerable regions to climate change globally (e.g. IPCC, 2007a; Giorgi
and Lionello, 2008; Trondalen, 2009; Bosello, et al., 2013). Greece moreover, is among the
areas identified as particularly affected in the Mediterranean region (Diffenbaugh, et al.,
2007). Substantial climate changes are projected with evident consistency in most models and
recent studies show that shifts are already occurring (e.g. Kostopoulou and Jones, 2005;
IPCC, 2007a; b; Mavromatis and Stathis, 2011).
In short, with global warming a “pole-ward extension” is expected of the seasonal shifts in
latitudes of the global circulation system. This means the Bermuda-Azores anticyclonic cell
will become more dominant and long-standing in the region. The dry summer season will thus
be prolonged and intensified and winter low pressures hampered and moderated (IPCC,
2007a; Giorgi and Lionello, 2008). Accordingly, P is confidently projected to decrease,
especially during summer and in terms of the number of rainy days in winter. IPCC (2007a)
Karin Ekstedt
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for example, predicts a total decrease in average P of 7-27% until 2090-2099 in the
Mediterranean (assembled models, SRES scenario A1B, reference period 1980-1999). The
corresponding modeling for T projects an increase of 2.2-5.1°C and particular warming in
summer. Many studies also point to higher rainfall intensity, higher interannual variability in
both P and T and a higher frequency and severity of extreme hot and dry weather conditions
(e.g. Diffenbaugh, et al., 2007; IPCC, 2007a; Trondalen, 2009; MEECC, 2010; Sánchez-
Canales, et al., 2012).
Naturally then, most models predict a decrease in runoff and ground water infiltration in the
Mediterranean basin (Trondalen, 2009; MEECC, 2010). This has, again, been confirmed in
several studies to occur already (e.g. García-Ruiz, et al., 2011; Mavromatis and Stathis, 2011).
IPCC (2007b) predicts a decrease in runoff of 0-23% until 2020 and of 6-36% until 2070 in
southern Europe (reference period 1961-1990). Together with increased interannual
variability, and a higher frequency and severity of droughts, this will cause notable
disturbances in hydrological systems altering the regime, quantity, quality and sustainability
of water resources. Environmental and social impacts extend also to for example forest fires,
losses of biodiversity, desertification and also effects in general health, tourism and energy
consumption (e.g. IPCC, 2007b; Trondalen, 2009; FAO, 2011; García-Ruiz, et al., 2011).
1.2.3. Land use and water resources
Both natural and anthropogenic changes in land cover and land use are also particularly
intense in the Mediterranean landscape, as they have been for the past 10 000 years (García-
Ruiz, et al., 2011), and many studies have shown related impact in the hydrological systems.
Particularly, vegetation has large influence on evapotranspiration and infiltration that affects
the quantity, quality and regime of rivers and aquifers (e.g. Brown, et al., 2005; Bhattarai, et
al., 2008; García-Ruiz, et al., 2011; Sánchez-Canales, et al., 2012). The actual influence will
always depend on specific catchment characteristics, such as soil water storage capacity and
climatic conditions, and new equilibriums can take many years to reach after permanent
changes occur (Bosch and Hewlett, 1982; Brown, et al., 2005).
In the Mediterranean, climatically induced water scarcity is projected to cause considerable
changes in land use and specifically, a decrease and degradation of arable cropland is
expected (e.g. MEECC, 2010; IPCC, 2007b; FAO, 2011; García-Ruiz, et al., 2011).
Agriculture has always been the main feature in Greek economy (Loy and Wright, 1972).
Sugar beets and olives dominate production and, after Spain and Italy, Greece is the third
largest producer of olives in the world (FAOSTAT, 2011). Due to the climatic conditions,
irrigation in Greece already accounts for 84% of total water consumption (MEECC, 2010) and
demands are increasing, partly also following growing markets for olive products and
intensification in agriculture (e.g. Metzidakis, et al., 2008; Iniesta, et al., 2009; Nainggolan, et
al., 2012). In Greece alone, the proportion of irrigated fields increased 22% 1990-2006
(MEECC, 2010).
Olive trees are resistant to drought and have long been cultivated in low density orchards
using rainfall only. New orchards however, are streamlined with higher density, less alternate
bearing behavior and effective drip irrigation (Beede and Goldhamer, 1994). Increasing water
Local water resource assessment in Messinia, Greece
9
demand however, poses an issue in water management and is a limiting factor for alternative
uses (Bosello, et al., 2013). Research is becoming progressively focused on estimating and
modeling specific and local irrigation requirements and it is crucial for sustainability that land
use and irrigation management is adapted accordingly (e.g. Orgaz, et al. 2006; Testi, et al.,
2006; Metzidakis, et al., 2008).
Coastal regions in the Mediterranean are under additional pressure from for example tourism
(which just like agriculture is an important feature in Mediterranean economies), denser
population and industry and, in addition, future scenarios indicate further intensification.
Tourism and agriculture in particular, cause seasonal imbalance in supply and demand that
above all generates large deficiencies in summer. It is not uncommon that aquifers here are
intensively and unsustainably exploited, not least along Greek coastlines, and that the issue of
salt water intrusion emerges (e.g. Cudennec, et al., 2007; MEECC, 2010; García-Ruiz, et al.,
2011; Mazi, et al., 2013). Increasing salinity, together with intense fertilization and use of
pesticides in agriculture, deteriorates water quality and affects all users in these areas (NTUA,
2007; Baltas, 2008).
1.2.4 Water management in Greece
There have been recent large-scale reorganizations in Greece restructuring a fragmented and
decentralized institutional framework with the merging of municipalities into larger units as
one of the main outcomes. Up until 2011 the former Ministry of Environment, Planning and
Public Works was the main body for environmental and water management (Tsagarakis, et
al., 2003) yet in the new system, water management is governed under the National Water
Commission chaired by the Ministry of Environment, Energy and Climate Change (MEECC).
The Special Secretariat for Water is then the body responsible for planning and coordinating
implementation between national and regional levels (MEECC, 2009).
There are 14 Water Regions in the country, with their own departments for water and waste
water, that are responsible for regional implementation of the national strategic planning
(Tsagarakis, et al., 2003; MEECC, 2009). Actual measures and management however is run at
municipal level. Most commonly, in municipalities with more than 10 000 inhabitants (and in
some with fewer), water is managed by the “Municipal Enterprise for Water Supply and
Sewage” (DEYA). There are now more than 200 DEYA in Greece and they serve about 35-
40% of the total population. The bigger cities of Athens and Thessaloniki have similar yet
somewhat different solutions and smaller municipalities cover management themselves
(Tsagarakis, et al., 2003; Safarikas, et al., 2006).
The DEYA is owned by the municipality and partly financed by the state yet it is run as a
private company rendering the enterprise flexible and efficient in its operation (Tsagarakis, et
al., 2003; Safarikas, et al., 2006). It owns the facilities, sets the water tariffs according to
operation costs and independently determines their extent of cooperation with private
companies. In effect it is responsible for constructing, maintaining and running local networks
for water supply and sewage and for verifying that quality is sufficient for environmental and
health requirements (Tsagarakis, et al., 2003).
Karin Ekstedt
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The DEYAs in Greece typically face several challenges, for example with loans, distributing
networks and sewage systems requiring expensive upgrades, inadequate monitoring,
increasing anthropogenic development and increasing quality issues in local water resources
(Tsagarakis, et al., 2003). In this context there are several studies that point to the importance
of strong institutional frameworks with political and economic stability, fewer water districts
(preferably at watershed-level as is set in the EU Water Framework Directive (WFD)) and
clear guidelines and assignment of responsibilities. Also commonly emphasized is the
significance of stakeholder integration; for information-sharing, for prevention of mistrust,
conflict and unawareness and for fair decision-making. This is particularly important
considering external political regulation commonly interferes with economic interests (e.g.
IPCC, 2007b; Baltas, 2008; García-Ruiz, et al., 2011; Bosello, et al., 2013). As mentioned, a
new legal framework is being developed in Greece in order to facilitate the enterprises and
water legislation is under continuous adjustment in correlation with the EU WFD (Tsagarakis,
et al., 2003) - which was the focus of the first meeting of the National Water Commission in
2010 (MEECC, 2009).
2. DATA AND METHODS
2.1 Site description Sellas, Gianouzagas and Xerias are three main rivers draining into the sea along the coast
between Costa Navarino and Pylos. Their headwaters are typically in the inland mountainous
areas where elevations reach more than 1000 m (Tab. 1a) but closer to the coast topography
levels out and the rivers flow through plains of fertile agriculture before reaching the sea (Fig.
2). The Sellas catchment is roughly twice the size of the Gianouzagas and Xerias catchments
and it also covers higher altitudes than does the other two.
The dominating land use in this area is olive agriculture (OLV). It covers around 70% of the
total catchment area in Sellas and Xerias and almost 90% in Gianouzagas (Tab. 1b). Other
vegetation, summed under “native vegetation” (NV), is diverse and includes coniferous,
broadleaved as well as sclerophyllous vegetation. Sparsely vegetated areas and shrubs are also
common but bare land and artificial surfaces cover no more than 1.5% in either of the
catchments (Lundholm, et al., 2009). Typically, geology is mainly made up of sandstone and
limestone while alluvial deposits dominate at the coastal plain between Gialova and
Romanos.
Table 1: Physical characteristics of the catchments: a. altitude statistics: average (avg) (also in Tab. 2),
standard deviation (std), minimum (min) and maximum (max) and b. areas: the total catchment, olive
agriculture (OLV) and “native” vegetation (NV).
a. Altitude statistics, masl b. Areas, km2 (%)
Avg std min max total OLV NV
Sellas 370 194 6 1041 87.7 65.2 (74) 22.6 (26)
Gianouzagas 268 100 20 703 39.0 34.7 (89) 4.4 (11)
Xerias 201 96 9 823 47.7 33.6 (70) 14.1 (30)
Local water resource assessment in Messinia, Greece
11
Figure 2: The three catchments, the local rainfall (P) and discharge (Q) gauging stations, local
villages, the two development sites of Costa Navarino, land use (Lundholm, et al., 2009) and elevation
relief (Delrue, unpubl.).
At this alluvial plain lies Gialova (Osmanaga) lagoon which is perhaps the most prominent
environmental feature in the area. It is an important wetland for more than 271 species of
residential and migratory birds and it is the only European residence for the African
chameleon (TEMES S.A., 2009a). Through the past decades however, it has been under much
anthropogenic pressure from for example freshwater withdrawals in agriculture, exhaustive
fishery, drainage and increasing infrastructure (HOS, 2013). The lagoon was formed gradually
Coordinate System: WGS 1984
Projection: Mercator Auxiliary Sphere
Land
useand
use
Land use
Karin Ekstedt
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through the successive steps of barrier formations that shaped Navarino Bay the last 9000
years. Today the floodplain is an inactive erosional environment but it was previously fed
with massive amounts of sediments from the Sellas River. The river was diverted just north of
Romanos during the Late Bronze Age (in the Mycenaean Era, 1600 BC - 1100 BC) in a
hydraulic project that created a clean water port for the palace of Nestor - the first known
artificial harbor installation of its size in Europe (Zangger, et al., 1997).
The area has been of high significance and both a cultural and demographic center through
history yet at present, it is a remote and rural area and population density is low (Zangger, et
al., 1997). NEO and Costa Navarino are located in the municipality of Pylos-Nestor, formed
from merging 6 former units in 2011, that has a population of 21 077 (38 people per km2, total
area 555 km2) and in which the main city is Pylos with 2 350 residents (ELSTAT, 2012). The
municipality has an oblong shape stretching from Palea Vrisi in the north to Koroni in
southeast. All in all, the area has high environmental and recreational values that make it an
attractive destination for tourism. Hitherto there has still only been little tourism yet the recent
establishment of Costa Navarino could make a turning point for such development. The resort
is likely to attract not only thousands of guests but also further local business and settlement
that will increase anthropogenic pressure on natural resources, such as water.
2.2 Data The water balances for the three catchments (see method section) were set up using local
discharge (Q) and P data series measured and provided by TEMES through NEO. They were
reported every 15 minutes and the longest records covered January 2009 to October 2012
(Tab. 2). There were six meteorological stations around the catchments (Fig. 2) that were set
up in a network by TEMES in 2008 to monitor for example T, humidity and wind speed. P
was gauged using weighing buckets and both missing data and outliers did occur in the series.
Q was measured in the rivers of Sellas, Gianouzagas and Xerias respectively (Fig. 2 and 3)
using an optical radar technique (Fig. 4). It was reported as an “instrument to water surface
distance” that was converted to a depth and rated into discharge. However, no explicit
information on the “instrument to river bed distance” was provided such that it was necessary
to assume it equal the highest “instrument to water surface distance” reported.
Under an initial quality control check the daily streamflow data series from Sellas appeared to
be the most reliable among the three. It had the most continuous record and a hydrograph
reflecting the expected river regime (Fig. 3). Gianouzagas on the other hand had very short
time coverage and its hydrograph, particularly considering i) the unexpectedly steady flows in
November 2010 - February 2012 and ii) the peculiar drop in March and April 2012, indicates
that the measurements were affected not only by natural factors and that there were errors
inherent in the observations.
Local water resource assessment in Messinia, Greece
13
Table 2: P and Q gauges set up by TEMES, their station names, time coverage, mean altitude and
average annual P or runoff (R, see below) respectively. Brackets in the last column give Q in m3/s.
Parameter Station Time period Altitude, m P/R (Q), mm/yr
P
Navarino Sep10 – May12 34 694
Moyzaki Jan09 – May12 436 1151
Chora Jan09 – May12 237 766
Handrinos Jan09 – Oct12 184 895
Sgrapa (Gialova) Jan09 – Oct12 14 660
Kynigos Jan09 – Oct12 311 880
Q
Sellas Jan09 – May12 370 378 (1.05)
Gianouzagas Jan09 – Apr12 268 392 (0.48)
Xerias Oct10 – May12 201 1602 (2.42)
The Xerias data series contained much missing data, several unaccountable extremes
(sometimes exceeding 70 m3/s) and reported values of questionable accuracy (see July-
October 2009 for example). For relevant presentation in Fig. 3, extremes have been cut and
missing data replaced by monthly averages. Because of data shortage and lack of reliability in
the records of Xerias, these monthly averages were estimated through correlation with Sellas:
the proportional relation between the monthly and the annual average “instrument to water
surface distance” in Sellas was applied to the annual average in Xerias thus giving an
approximation of the corresponding monthly values. The correlation was justified given i) the
spatial proximity, ii) the assumption of similar hydrological regimes and iii) the statistical
similarity of the monthly average measurements in the two catchments despite deviation some
months (the annual average/standard deviation of the “instrument to water surface distance” is
302/11 and 366/16 mm in Sellas and Xerias respectively).
It should be mentioned that the data available for constructing rating curves in the three
catchments were limited to six (three in Xerias) monthly average water levels and their
corresponding Q values in January-June 2012 only. These were presumably measured at the
same cross section as where the daily data was collected. Also, from personal communication
with local sources and observation on location it appears that the river beds are unstable with
erosion and sedimentation of up to 30 cm or more at times. Water is furthermore transferred
to surface water reservoirs (see the result section) from all three rivers (TEMES S.A., 2009b).
To our knowledge however, Q is measured upstream from these artificial outlet points so they
should not have influence over the resultant water balance.
Karin Ekstedt
14
Figure 3: The hydrographs of the three rivers with the set hydrological years marked with
crosshatched vertical lines. In black is runoff (R, see below) and in blue the catchment precipitation
(P, on the secondary y-axis), both in mm/yr. Notice that the vertical axis for R in Xerias has a larger
scale than the other two. For legibility extremes of R have been cut in Sellas (2176 mm/yr the 7
February 2012) and Xerias (several, with the highest being 49 114 mm/yr (!) the 28 December 2009).
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6000
7000
8000Xerias
R (
mm
/yr
)
Local water resource assessment in Messinia, Greece
15
For other spatial analyses there was also a digital elevation model (DEM) with a resolution of
30 m and a land use shape file available from previous studies performed by Delrue (unpubl.
data) and Lundholm et al. (2009) respectively (Fig. 2). The catchments were delineated, and
their areas estimated, using the DEM and hydrological tools in ESRI ArcGIS. The same
software was used for evaluating the land cover distributions in the catchments, as based on
the land use shape file. This land use map was made on a regional scale covering the whole of
Messinia hence it gives a rough estimation of local distribution only. It should be noted that
because the exact locations of the Q gauges were not specified, there might be an offset of
these to the delineation points.
Figure 4: (a) Local meteorological
station measuring for example T and
P and (b) the radar instrument used
for measuring river stage. Photo
courtesy: TEMES (a) and Victoras
Plevrakis (b).
Finally, there was information provided by Konstantine Boulolis, an agronomist active in
Gargaliani (a city 7.6 km from Costa Navarino located outside the municipality of Pylos-
Nestor, see Fig. 2), on approximate irrigation amounts applied seasonally in the local olive
orchards. This estimation was based on his experience and on “irrigation diaries” filled and
turned in by his client farmers reporting field characteristics, dates, duration and volumes of
irrigation (Fig. 5). Importantly, this is an approximation of applied amounts only.
Figure 5: Example of an irrigation diary filled in by a local farmer and collected by agronomist
Konstantine Boulolis in Gargailianoi, Messinia. The first column gives the field ID, the second and
third the date and hours of irrigation respectively and the fourth the quantity of water for each tree
(translation Magdalini Zampouni). Field characteristics are given in a separate form.
(a) (b)
Karin Ekstedt
16
2.3 Methods
2.3.1 The water balances
There is no limit to the possible complexity of water resources modeling. Data demands and
uncertainty increase rapidly the more comprehensive the evaluation and the higher the
number of parameters included. The water balance is a straightforward method for evaluating
water availability with little data yet sufficient accuracy. It can be used on any temporal and
spatial scale, yet again; the finer the resolution the higher the demand for detail and precision.
Depending on the assumptions made, the water balance equation can be set with varying
complexity but the basic concept is for inputs to the water system to equal outputs. Assuming
no trans-boundary transfer of water, the balance can be written as:
where P is precipitation, ET evapotranspiration, R runoff ( ), ΔS
change in storage (including ground water, soil moisture, snow/ice and lakes/rivers/reservoirs)
and μ is the balance discrepancy (preferably close to zero) (Senay, et al., 2011). For large
spatial scales and long time periods this equation can be reduced into:
while assuming:
(1) The change in storage is zero. This assumption is (most often) valid when studying
long time series, at least one year, where temporal variability is balanced (i.e. the
system approaches an approximate steady state). The longer the time considered the
greater the power of this assumption. When using this form for shorter time periods,
such as for individual months, contributions due to ΔS cannot be ignored.
(2) The discrepancy (uncertainty and errors) is negligible and “embedded” in the
parameters left.
Evapotranspiration is difficult to measure and is more conveniently evaluated as the residual
that closes the balance. Eq. 2 is therefore rearranged into:
which was the simple equation employed in this study on catchment scale and on an annual
basis.
Local water resource assessment in Messinia, Greece
17
Ideally the annual water balance would be evaluated for the hydrological year (HY) starting in
September when discharge is lowest. However, in order to use the available time period of
data optimally, the HY was set to start in May (HYMay). Annual catchment P was estimated
through inverse distance weighed averages (IDWA) i.e. through weighing the nearest gauges
(Tab. 3) according to their proximity to the catchment center. Thus, the closer the gauge the
greater was the influence on the average. Orographic variance caused uncertainty in
interpolation and there was a lack of gauging stations at higher altitudes where P was richer
(Tab. 2 and Fig. 6). Moyzaki was the closest equivalent with the highest P and was therefore
given additional weight when estimating P in Sellas. For the same reason, i.e. better
representation of the orographic setting, both Navarino and Sgrapa stations were excluded
completely from the calculations.
Table 3: The stations (x) used for the IDWA estimations in each catchment.
Navarino Moyzaki Chora Handrinos Sgrapa Kynigos
Sellas - x x x - -
Gianouzagas - - x x - x
Xerias - - - x - x
Figure 6: Annual average precipitation (HYMay, 2009-2012 or the time available) as a function of
altitude at the local meteorological stations set up by TEMES.
Navarino
Moyzaki
Chora
Handrinos
Sgrapa
Kynigos
500
600
700
800
900
1000
1100
1200
0 100 200 300 400 500
An
nual
P
(mm
)
Altitude (m)
Karin Ekstedt
18
2.3.2 ET of local vegetation
The ET of local vegetation was required for subsequent land use modeling. For simplicity and
relevant accuracy (especially with the crude land use map available), the current land cover
was classified into two categories only, again: olive agriculture (OLV) and “native”
(other) vegetation (NV). These were then characterized by their different ET values, initially
taken from literature. All studies reviewed for this purpose (Fig. A1 and marked with asterisks
in the reference list) were performed in Mediterranean climate, either in the Mediterranean
countries or in California (one in Arizona), U.S. The primary methods employed were i) eddy
covariance measurements, ii) different kinds of modeling or iii) water balance approaches. All
in all, 21 reported annual numbers were noted and averaged into approximate representative
ET values for both OLV and NV.
These literature values were then calibrated to local conditions and scaled to the three
catchments. This was possible with the underlining assumption that the relative distribution
(represented as a ratio, rlit, Eq. 4) between the literature ET values of regional OLV and NV
(ETo_lit and ETn_lit respectively), applies also to the local area. Scaling was done through
combining this ratio with the ET balance in each catchment (Eq. 5). This balance states that:
the total volume of ET (ETt*At) from the catchment, which was estimated in the water balance
(Eq. 3), equals the summed ET volume from OLV and NV (Ax*ETx). Eq. 4 and 5 were
rearranged and combined into Eq. 6, in which ETn in the local catchments can be
approximated. Based on this result and Eq. 4, ETo was then estimated in a fourth and final
step (A = area, t = catchment total, o = OLV and n =NV).
⁄
)
⁄
2.3.3 Hypothetical land use intensification
Focus then fell on possible land use change and on how the introduction of an additional
highly evaporative vegetative cover would affect the current land use - and water balances.
This hypothetical land cover (HYP) was assumed to have an ET (ETh) close to PET (scenarios
A-C, Tab. 4) resulting from any intensive land use with for example high water demands
and/or exhaustive irrigation. The PET was correlated to literature (average of all studies
reviewed is 1240 mm/yr) but also to local Priestly-Taylor modeling performed in the Sellas
catchment (again 1240 mm/yr) (Klein, unpubl.). Two opposite alternatives of water
management were addressed when introducing HYP: that of maintaining the current
(presumably) sustainable water consumption (Model 1) and that of consuming surface water
until no basin outflow remains (Q = 0) (Model 2). Of course there exists a range of plausible
water exploitation between these yet focus here is on the end-point scenarios.
Table 4: The three scenarios, A, B and C, of ETh in mm/yr. Scenario C resembles PET, A is set to a
lower value close to P (average for all three catchments is 893 mm/yr) and B is their average.
A B C
ETh, mm/yr 900 1075 1250
Local water resource assessment in Messinia, Greece
19
Model 1
Model 1 returned what measures are required in land management regarding the areas of OLV
and NV, to compensate for HYP and maintain the current water balance. The principal
underlining base (Eq. 7) of the model was the same as in Eq. 5 yet here also HYP was
included (ETh*Ah). Eq. 8 offers a way of substituting for the area of NV (An) through the fact
that all sub-areas add up to the total area. It was used also for back-calculating An after
retrieving the decreased area of OLV (Ao) in Eq. 9. This equation originates from combining
Eq. 7 and 8 and then solving for Ao.
⁄
Model 2
Model 2 addressed the theoretical capacity of accommodating HYP before ET exceeds P if
river flow (Q) would instead be completely exhausted for satisfying the HYP water need. It
was set up based on the same ET-balance as in Model 1 only this time, the initial land use
distribution was considered plus P replaced ETt on the left-hand side since Q was added to
total availability. It was run in two sub-sets assuming that i) the HYP replaces all NV first and
then OLV (case 1, Eq. 10-11) and ii) only OLV is replaced by the HYP (case 2, Eq. 12-13).
Eq. 11 and 13 originates from solving for Ah_max in Eq. 10 and 12 respectively.
( )
( )
In both models (Eq. 7-13) it was assumed that:
(1) PET, and thus ETh, was the same in all three catchments despite possible difference in
their water balances. This should be justified considering the dependence of PET on P
and T primarily, which both have low spatial variability.
(2) The ratio between ETo and ETn as derived from literature was the same in all three
catchments, which presupposes plants and their physical conditions were similar.
Applying literature values in the first place is a considerable source of uncertainty that
will be addressed in later discussion.
(3) ETn was representative of all “other” land uses than olive agriculture.
(4) Ah increased with a percentage of the total and respective catchment area, rather than
with a set magnitude equal in all three catchments.
Karin Ekstedt
20
(5) The 2009-2012 average P and ET values were representative for the long-term
regional conditions.
(6) There was no transboundary exchange of water between the catchments.
2.3.4 Interviews and questionnaires
The qualitative assessment of water resources was performed by reviewing literature,
distributing questionnaires and through simple interviews with concerned actors on location
(Tab. 5). The purpose was to investigate how local water resources are managed, what the
dominating water uses are and what “pressures” exist on water availability - between different
actors and in current and future development. The interviews were set up in an open semi-
structured way collecting a narrative and leaving open the possibility of adapting questions
and discussions to the interviewee. A Dictaphone was brought for the interviews but
functional issues unfortunately hindered recordings.
The questionnaire (Appendix B) was put together with the purpose of gathering general
thoughts and opinions from local residents and actors. It was made available both in English
and Greek (translation to Greek by Katerina Mazi). Tab. 6 lists the occupation, gender, age
and residence city of the contributors that filled in the questionnaire. Most have connection to
agriculture (two agronomists and 12 farmers), some are active at Costa Navarino and NEO (8
people) and the rest are “other” local stakeholders. Most interviews and questionnaires were
collected on location in June-July 2012 but answers were also brought in afterwards via e-
mail.
Table 5: Interview dates and the names and occupation/position of the people interviewed.
Date Name Occupation/position
9 July 2012 Efstathia Zontanou Supervising agronomist at the producer’s group Nileas,
Chora
10 July 2012 Giorgos Maneas Station manager at NEO from June 2012, former head of
the HOS* Gialova lagoon project
28 July 2012 Konstantine Boulolis Agronomist, Gargaliani
10 July 2012 Panagiotis Andrianopoulos
& Nikitas Crikas General and technical managers at DEYA Pylos**
17 July 2012 Vasilis Karakousis Environment and sustainability manager at TEMES
*The Hellenic Ornithological Society, runs environmental protection work at Gialova lagoon among many other
things.
** ΔΕΥΑΠ, public-service corporation responsible for drinking water supply and waste water treatment in the
municipality of Pylos- Nestor.
Local water resource assessment in Messinia, Greece
21
Table 6: Name, occupation, gender (1=female, 2=male), age and city of residence of the individuals
that filled in the questionnaires in the order of collection (CN = Costa Navarino).
Name Occupation Gender Age Residence
1 Konstantine
Bouloulis Agronomist 2 42 Gargaliani
2 Theodoras
Kostadopulos Farmer 2 38 Gargaliani
3 Panagiotis
Panagiotopoulos Farmer 2 54
Floka (ΦΛΟΚΑ)
(Gargaliani)
4 Helen Boulouli Farmer 1 - Gargaliani
5 Ioannis Boulouli Farmer 2 - Gargaliani
6 Ioanna
Karamichalou Buisiness woman 1 47 Gialova
7 - Restaurant owner /
merchant 1 50 Gialova
8 Ioannis Lopas Pharmacist 2 50 Romanos
9 Dimitrios Kajas Agronomist 2 40 Chora
10 - Farmer 2 32 Pyrgos (north)
11 - Farmer / gym teacher 2 44 Chora
12 - Private employee 1 33 Chora
13 Giorgos Melcher Electrical engineer at CN 2 52 Gialova
14 Heleni
Georgiopoulou
Student and farmer’s
daughter 1 20 Chora
15 Dionisis Sampolis Farmer 2 58 Filiatra
16 Nikos Kalivitis Physicist, former NEO
station manager 2 35 (Crete)
17 Giorgos Maneas NEO station manager,
former head of HOS 2 32 Kalamata
18 Dimitrakopoulos
Takis Farmer, Nileas 2 49 Chora
19 - Farmer, Nileas 2 58 Chora
20 - Farmer, Nileas 2 48 Chora
21 - Farmer, Nileas 2 52 Chora
22 - Farmer, Nileas 2 45 Chora
23 Raphaella Tsianti Hotel employee, CN 1 - Pylos
24 - Hotel employee, CN 1 29 Marathopoli
25 - Civil engineer, CN 2 42 Kalamata
26 Georgia (Vlahou) Director of conventions
and events, CN 1 52 Greece
27 Natasa Glaraki Assistant to the Chief
Destination Officer, CN 1 32 Kalamata
Karin Ekstedt
22
3. RESULTS
3.1 The water balances The annual water balance (Eq. 3) for the three considered catchments are shown in Fig. 7 and
Tab. 7 below. Because the estimated R in Xerias (averaging 1602 mm/yr) exceeds rainfall
input, the water balance cannot be closed and the catchment is therefore not considered in
further analysis. In Gianouzagas, time coverage and data quality are clearly limited. However,
average water balance terms HYMay 11-12 (HY3) are similar to Sellas, which indicates that
available data are consistent.
P data is available throughout the whole period and annual patterns of rainfall are similar
across all catchments. Comparing the hydrological years, HY3 is generally the wettest, HYMay
10-11 (HY2) the driest and HYMay 09-10 (HY1) is closer to the average of the three years. The
interpolated annual average P across all the catchments is 893 mm and spatial difference
(averaging 39 mm) is smaller than the interannual (averaging 97 mm).
Figure 7: The water balance parameters of the three catchments HY1-3: P (black), R (crosshatched)
and ET (white). Notice that the vertical axis for Xerias has a larger scale than the other two. All values
are in mm.
Table 7: The actual water balance values (P, R (% of P) and ET estimated as P minus R) in the three
catchments. All values are in mm/yr.
Sellas
Gianouzagas
Xerias
HYMay P R ET
P R ET
P R ET
09-10 891 416 (47) 476
862 - -
915 2148 (235) -
10-11 834 302 (36) 532
839 - -
812 1166 (144) -
11-12 1024 416 (41) 608
928 393 (42) 535
930 1483 (159) -
Average 916 378 (41) 539
876 392 (45) 484
886 1602 (181) -
0
200
400
600
800
1000
1200 Sellas
P
Q
ET
0
200
400
600
800
1000
1200 Gianouzagas
P
Q
ET
0
400
800
1200
1600
2000 Xerias
P
R
ET
Am
oun
t o
f w
ater
(m
m)
Local water resource assessment in Messinia, Greece
23
3.2 ET of local vegetation and olive irrigation Tab. 8 shows a summary of the average ET in OLV and NV obtained through the literature
review and the estimated catchment ET values reached after water balance closure and
calibration. As can be seen, OLV has 1.78 times the ET of NV in this type of climate and, even
if they differ from the regional estimations, the calibrated catchment numbers are fairly
similar in the two catchments of Sellas and Gianouzagas. ETo and ETn in Gianouzagas amount
to 93% of the same values in Sellas while their average is only 80% of the regional
estimation.
Table 8: Regional ET numbers attained from the literature review (ETo_lit and ETn_lit), their ratio (rlit)
and the ETo and ETn scaled to the catchments of Sellas and Gianouzagas respectively. All values apart
from the ratio (no unit) are in mm/yr.
Regional Sellas Gianouzagas
ETo_lit ETn_lit rlit ETo ETn ETo ETn
730 410 1.78 607 341 563 316
In the literature reviewed were also estimations of applied irrigation amounts, all in the
Mediterranean region. These range from 181 mm/yr (Fernández, et al., 2006) to 403 mm/yr
(Palomo, et al., 2002) and averages 300 mm/yr (additionally: Fernández, et al., 1998; Orgaz
and Fereres, 2004; Pastor, 2005; Tognetti, et al., 2006). Also, the average tree density is 223
trees/ha. Local olive fields, according to Mr. Boulolis agronomist in Gargaliani, are irrigated
approximately once every second week during the warm and dry season June-September and
then harvested in October-December. Generally and based on farmers’ irrigation diaries, the
average size of a local farm is 1 ha, the tree density is 200 trees/ha and each tree consumes 1
ton of water per 10 days from July to September. Small trees would need half the water. A
rough estimation based on these numbers results in an irrigation amount of around 100-150
mm/yr in the local area (11-17% of total annual rainfall (2009-2012)) depending on land
cover distribution, proportion of irrigated agriculture and proportion of “grown” vs. “small”
trees. The extra water evaporated from OLV in relation to NV (estimated above) corresponds
to 200 mm/yr and 220 mm/yr on catchment scale in Sellas and Gianouzagas respectively.
3.3 Hypothetical land use intensification
3.3.1 Model 1
The primary result of simulation in Model 1 in Sellas is a clear increase in the ratio of An to Ao
(An/Ao) as HYP covers an increasing proportion of the catchment (Fig. 8, upper chart). This
response is similar to that in Gianouzagas (Appendix C and Fig. C1 therein) which supports
consistency in the model results. Common for both catchments also is that An/Ao grows more
rapidly i) the higher the ETh (compare scenario A to B to C), and ii) the larger the Ah
introduced (growth is non-linear). Also, the larger the scale of development the greater is the
influence of ETh.
Karin Ekstedt
24
0
0,4
0,8
1,2
1,6
2
0 5 10 15 20 25
An/
Ao
Ah (% of At)
A
B
C
0%
20%
40%
60%
80%
100%
0 5 10 15 20 25
% o
f A
t
Ah (% of At)
Χ
Χ
Figure 8: 0 < An/Ao < 2 as a function of Ah introduced in the catchment of Sellas under the three ETh
scenarios (A = 900, B = 1075 and C = 1250 mm/yr of ETh) (upper chart) and a stacked area diagram
showing the change in distribution between Ao (white), An (checked) and Ah (black) in scenario C
(lower chart). The markings indicate corresponding points in the upper and lower charts of Ao = An
(An/Ao = 1) and An = 2Ao (An/Ao = 2) respectively.
In accordance with the linearity of the model, Ao and An change with constant rates (Fig. 8,
lower chart). The rate of decrease in Ao (ΔAo/ΔAh) is -2.1 in scenario A, -2.8 in scenario B and
-3.4 in scenario C. This latter value also represents the slope of the boundary separating Ao
and An in the lower chart of Fig. 8. As Ao approaches zero, An/Ao reaches infinity and the
asymptote of the curve will correspond to the Ah theoretically possible before inevitably
affecting the water balance (i.e., violating the conversation of mass assumption inherent to the
approach). In Sellas, this occurs at Ah ≈ 31.1 km2 (35% of At) in scenario A, 23.7 km
2 (27%)
in scenario B and 19.1 km2 (22%, also visible in the lower chart of Fig. 8) in scenario C
respectively (the dependence of maximum Ah on ETh is non-linear). The markings in Fig. 8
relate the upper and lower charts and are set at An/Ao equaling 1 and 2 respectively.
Local water resource assessment in Messinia, Greece
25
3.3.2 Model 2
Because of the model structure, the response of Ah_max to the proportion of Q exploited in
Model 2 is fully linear. Focusing on the scenario of exhaustive water consumption, however,
Tab. 9 presents Ah_max in Sellas under the different cases and scenarios considered. Again,
simulations in Gianouzagas result in similar results, i.e. the proportions of At feasibly covered
by HYP in the two catchments are similar. In scenario C for example, Ah_max is around 50%
and 60% of At in both catchments in case 1 and 2 respectively.
Generally, in case 2 where only OLV is converted, larger areas of HYP are feasible compared
to case 1 where NV is converted initially. Ah_max in case 1 is 18% smaller than in case 2
through all scenarios A-C in Sellas. It is furthermore clear that ETh has a considerable
influence on Ah_max in both cases. Ah_max in scenario A, for example, is more than 200% of that
in scenario C. Also, Model 2 evidently generates larger areas of HYP feasible than Model 1.
This can be seen by comparing Ah = 19.1 km2 at Ao = 0 to Ah_max = 42.1 km
2 (case 1) and 51.1
km2
(case 2) in scenario C.
Table 9: The results of Model 2 in Sellas, i.e. the largest area of HYP possible (Ah_max, km2 (% of At))
before exceeding P if Q is completely exhausted. Case 1 assumes (all) NV is converted first and case 2
that no NV is used (i.e. only OLV is converted) (A = 900, B = 1075 and C = 1250 mm/yr of ETh).
Case 1 Case 2
A B C A B C
Ah_max, km2(% of At) 92.5 (105) 57.9 (66) 42.1 (48) 113.0 (129) 70.7 (81) 51.1 (59)
Finally, it should be noted that neither case 1 and 2 in Model 2 can be directly translated to
Model 1. The latter corresponds to a case where the “remaining” ET after satisfying ETh (ETt -
ETh) is “distributed” between OLV and NV regardless of their initial areas (only At and Ah are
decisive in Eq. 6). Changes therefore occur in Ao (decrease) and An (increase) simultaneously
and theoretically, Ao is transformed to both Ah and An.
3.4 The interviews and questionnaires This section provides a summary and overview of the narratives, information and opinions
gathered through the interviews and questionnaires. Interpretation and connective reasoning
are found in discussion below.
3.4.1 The questionnaires: Opinions of local actors
Fig. 9 illustrates the statistics generated with the questionnaires. For clarification, the answers
to question (Qn) 3 have been converted (see the box below) to merge with the graph. For
completeness with regard to this question, 20 people answered “decreased”, 3 answered
“unchanged” and another 3 “increased”. The oral and written comments given in connection
to the questionnaires are summarized in Tab. D1.
Karin Ekstedt
26
1. Access to water is important in my daily life/work 2. Water availability limits my daily life/work 3. In recent years, water availability has: increased(10) / been unchanged(5) / decreased(1) 4. I am well informed about rules and regulation regarding the use of water for my daily life/work 5. Water availability may limit my daily life/planned work in the future 6. I am well informed about water management in the region and know how it is handled 7. Water resources are well treated and managed in the region/basin 8. The water policies and management plans are transparent and allow for involvement of local
stakeholders/actors 9. There are no conflicting interests for water use in the region/basin 10. The current water resources are enough to protect the environment and the ecosystems in the region
Figure 9: Graph illustrating the questionnaire statistics and a presentation of the corresponding
questions below. The grey bars indicate the mean of all answers, the triangles show the mean of the
farmers, the asterisks the modes (the most common answers), the intervals indicate standard deviation
(std) and the numbers at the bottom indicate the number of “no opinion/do not know” answers.
There is agreement that water is indeed an important factor (Fig. 9, Qn1) and that many
consider water availability as limiting in their daily activities (Qn2). Furthermore, despite a
larger spread, the majority of those surveyed believe water resources have decreased in recent
years (Qn3) and that availability will become increasingly limiting in future operations (Qn5).
Farmers’ opinion generally follows the overall average yet in Qn5, it deviates towards a
stronger agreement of future restraints compared to average.
Regarding rules and regulations of individual water consumption (Qn4), most who answered
seem to be well informed yet there is a wide spread in replies. For regional water management
there was even greater spread and average is somewhat lower (Qn6). As for the opinion then,
on how water management is run, water resources are not seen as well treated (Qn7) and
transparency in processes and plans is regarded as low (Qn8). Furthermore, the opinion
appears to be that there are indeed conflicting interests around the local water resources,
1 1 3 2 3 4 5 4 0
1
2
3
4
5
6
7
8
9
10
11
12
1 2 3 4 5 6 7 8 9 10
An
swer
(1=
do
no
t ag
ree,
10 =
agr
ee f
ully
)
Question (see box below)
Mean Farmers Mode
no opinion/ do not know
Local water resource assessment in Messinia, Greece
27
though 19% gave no opinion (Qn9). Finally, however, the amount of water currently available
is mostly seen as sufficient for protecting environmental values (Qn10). Still, also here the
opinions diverge; 4 people checked box 1 (water is not sufficient for environmental
protection) and another 4 “do not know”.
3.4.2 The interviews: Narratives of local key actors
Mr. Andrianopoulos and Mr. Crikas: Water management in the municipality of Pylos-Nestor
Water management in the municipality of Pylos-Nestor is accounted for by “ΔΕΥΑ
ΠΥΛΟΥ”: DEYA Pylos (DEYAP). Its board members are assigned, and regulations and
activities are approved for, by the municipality. Apart from facilitating technical water
management it has a responsibility also to regulate public water use and to inform and raise
public awareness regarding water related issues. Local stakeholders are integrated in the
management process by allowing two of the seven seats on the board to one “commercial
representative” and one “local citizen”, respectively. By law, the company must produce and
distribute a yearly booklet accounting for their operation and plans, guidelines for local
citizens and for costs of water use. As for the implementation of the EU WFD there is so far
no regional river basin authority installed in the region. However, the Ministry of
Environment, Energy and Climate Change is gradually gathering data from local authorities
to set up a large-scale plan for implementation. Furthermore, the directive is incorporated in
legislation (N.1069/80) that governs local water management already.
Most drinking water in the region is from subsurface aquifers located inland at higher
altitudes. Water to the areas of Pylos and Gialova (round Gianouzagas and Xerias) is
transferred from the Chandrinou springs while to the areas of Chora and Costa Navarino (the
Sellas catchment) water it is taken from the springs of Kefalovriso near Chora. There are two
additional withdrawals closer to Gialova but because of high salinity - 1500 μS/cm compared
to a maximum allowance within EU of 2500 μS/cm - these are used only rarely.
There are no bigger industries hence the main consumers on the network, approximately in
order of mentioning, are the hotels, restaurants and households. Farmers use separate wells for
irrigation and up till now there has been little control of their number and withdrawal. In 2012
however, all wells were reregistered in accordance with new regulation. New permissions
will be handed out successively from the Peloponnese prefecture and hydrometers will be
installed to control water consumption. In the municipality of Filiatra northwest of Pylos three
to four reservoirs were recently constructed for municipal irrigation supply but no such
solution exist round Pylos.
Waste water treatment is set up in two different systems. The first involves a local treatment
plant in Pylos where water from those connected to the network is treated biologically and
then discharged into the sea outside the village. Restriction levels are set by the Ministry of
Environment and are checked by chemical engineers three times a week. There are about
20 000 residents in the municipality and the system was constructed to cover 16 000 of these.
Currently, less than 20% of the municipality population and about 50% of population in the
village of Pylos are connected. The rest, counted to the second system, collects their waste
Karin Ekstedt
28
water in tanks that are regularly emptied and transported to Kalamata for treatment. There
also exist separate small-scale solutions that mainly discharge into ground water or supply
agriculture with irrigation water and fertilization. The size and oblong shape of the
municipality, together with the scattered layout of small villages and touristic activities, make
it a complex task to connect all households to the local network. Still, there are plans for a
new plant close to Gialova that will cover 60-70% of the population and all in Pylos.
There are issues of seasonal shortages in the area and one of the main issues at these times is
the public’s unawareness of the circumstances. Water is wasted for washing streets and
watering gardens despite temporary restrictions. It usually passes, however, with the
municipality “closing their eyes”. Currently there is no control of the actual flow magnitudes
in the distributing network. DEYAP is therefore planning to install a monitoring system that
will enable real-time measurements, troubleshooting and balancing of in- and outflows. There
are thoughts of trying water pricing to regulate consumption, it has proven successful in
reducing water use in Athens earlier. For increasing and securing water supply there are plans
for withdrawing water from another aquifer at Eleofito near Pylos. The Environmental Impact
Assessment (EIA) has been approved by the prefecture, grants have been given at EU-level
and the pumping stations are now under construction. It will supply the new Costa Navarino
development in Navarino Bay but primarily also Pylos and surrounding villages. This water is
of lower salinity (600 μS/cm) and will substitute for the water pumped at times from Gialova.
To compensate summer shortages further, there are ideas also of desalinization and of
constructing surface water reservoirs similar to those of Costa Navarino (see below). There is
currently no budget for such plans however.
Mr. Boulolis: Local agriculture and water management
Olives dominate agriculture in the area and there are 1000-2000 olive farms and 12 active
agronomists within 10 km of Gargaliani only. Other common crops are grapes, blackcurrant
and vegetables. Grapes and blackcurrant are generally not irrigated but vegetables, such as
tomatoes, cucumbers and peppers, grown in greenhouses consume a considerable amount of
water, as much as 80 tons/day/ha approximately (compared to 20 tons/day/ha in OLV).
The most common technique in olive agriculture is drip irrigation and water is mainly
withdrawn from separate ground water wells. Almost all local wells were constructed before
the 1990’s by groups of farmers joining in cooperatives and sharing the costs. The only
requirement was a license for the construction and electricity and farmers now only pay for
the latter, about 3 Euro per hour, while water is free. In Filiatra farmers pay about 8 Euro per
hour for the water, electricity and service of the municipal supply. The wells are usually 100-
150 m deep but the oldest ones are around 20-30 m and used for drinking water and small-
scale irrigation only. Because there is a set minimum distance between the wells there is
basically no room for new ones in the area. Farmers requiring additional water turn to existing
cooperatives and surplus for access is not uncommon.
Much water has been exploited for irrigation, especially around the 80’s. Water availability
has been considered high and withdrawals have allegedly not affected the aquifers. Boulolis
expresses however, that recent climatic changes have caused higher irrigation demands and
Local water resource assessment in Messinia, Greece
29
less rainfall for ground water recharge. In shallow wells down to 20-30 m, there have been
signs of declining water levels and increasing salinity of up to 2500-2700 μS/cm. Also, there
is an issue of pollution from garbage deposited in the cities contaminating the proximate
aquifers.
In later years nonetheless, there have been attempts to optimize and reduce water
consumption and thereby increase sustainability. In Gargaliani, agronomists and farmers have
been cooperating around education on irrigation and integrated crop management the last ten
years (Fig. 10). In addition, the recent governmental initiative aiming to map out the irrigation
system and regulate water consumption, has required farmers to fill in forms reporting the
location of the wells, use of electricity and the amounts and purpose of irrigation. The
workload for the agronomists has been comprehensive yet it is important for the farmers to
receive the necessary license to continue irrigation.
Figure 10: Farmer (in orange) and
agronomists during a quality system
inspection in a local olive field. Photo
courtesy: Konstantine Boulolis.
Mrs. Zontanou: Ecological farming and water management
Nileas is an emergent corporation in Chora that is gathering farmers for achieving good
quality ecological farming. The organization has two agronomists that offer advice on for
example the use of pesticides and fertilizers and on water management in olive agriculture.
They also help with environmental certification such as for the EU Eco-Management and
Audit Scheme (EMAS) and the Environmental Product Declaration (EPD) (in cooperation
with the Swedish-based secretariat). The corporation now encompasses around 90 producers
and exports organic olive oil produced since 2002 to Austria, Germany, Canada, and the U.S.
and there is a quickly growing interest and market for its services and products.
There is no support for this type of activity from the ministry and related ongoing
governmental programs are very slow. With the upcoming new permission system, Nileas has
assisted its member farmers with controls and paperwork that will provide the information for
new irrigation licenses. With this there will be increased regulation adapted to the local
aquifers yet because olive trees consume little water, farmers rarely exceed restrictions.
Again, there is no general system for common irrigation water supply yet it might be
beneficial to construct a municipal dam for such purposes in the future.
Karin Ekstedt
30
Mr. Karakousis: Costa Navarino and water management
Planning the resort from its initial stage TEMES has had the possibility of incorporating water
management from the start and it has been done with high ambitions of sustainability. At the
very first a thorough and scientific investigation (which has not been reviewed in this study)
was financed to examine the local hydrogeological setting and used by the developers to set
up the resort’s water supply. This survey has also been made available to the municipality and
prefecture to be used in public water management planning. Furthermore, TEMES has
assisted with new mapping and data for the additional wells around Pylos planned in
collaboration with the municipality. The developers also engage in local communities and
environment and did for example contribute financially to hydrological studies in Gialova
lagoon (see below).
Drinking water for the resort is, as given by law, taken from the municipal supply but internal
water saving schemes minimize demands. For golf course irrigation, a separate system has
been developed. In order to evade adding pressure on local aquifers and to maintain
sustainability TEMES built two surface water reservoirs for this purpose. These have a total
capacity of 700 000 m3 and are recharged from the local rivers in the area: Sellas,
Gianouzagas and Xerias. The one at Korifasi supplies the courses at Navarino Dunes and the
one near Pylos (Fig. 11) is used for those at Navarino Bay (Fig. 2). In general, the reservoirs
are exploited during summer with peaking demands in August, and are refilled again during
autumn and winter.
Figure 11: The surface water reservoir constructed by TEMES close to Pylos. Photo: Karin Ekstedt.
The volume of extraction is regulated by a license and controlled by the water authority at the
Peloponnese prefecture. No more than 2% of winter discharge is used for filling the tanks and
an environmental permit at ministerial level verifies that the local river ecosystems will not be
disturbed. The actual irrigation is furthermore optimized via meteorological monitoring
systems and through models connected to automatic sprinkler installations. As a
supplementary source, internal waste water treated by TEMES in their own treatment plant is
also put in use for the golf course irrigation. Finally also, a variety of grass has been planted
that requires less water than would the average types.
Local water resource assessment in Messinia, Greece
31
Mr. Maneas: Gialova lagoon and water management
Regarding Gialova lagoon there is currently no particular plan for its water management. The
area is protected under Natura 2000 and it has become important to the touristic development.
Conservation of the lagoon started in 1998 after two local oil spills in 1992 and 1996
respectively. The EIA brought up the wealth of the ecosystem but also its dystrophic crisis
caused by years of drainage, exploitation, eutrophication and pollution. HOS has been running
the protection programs since, financed through the EU LIFE project, and the wetland is now
classified as an “Important Bird Area”, a “Special Protection Area” and a “Site of Community
Interest”. The municipality also cooperates with HOS in a program called “Conservation and
Awareness”.
In one of the conservation projects in 2000 one managed for example, to reopen two of the
drainage channels to recover the wetland. Attempts have been made also at reducing the
farmers’ water consumption and thereby increasing freshwater recharge, yet these have been
fruitless and levels of salinity are still too high. The study made in cooperation with TEMES
was completed in 2 years and included the collection of for example salinity, oxygen,
temperature, phosphorus and phytoplankton data, and it has resulted in a number of
management directives. There is a need, for example, to have a freshwater reservoir to support
the wetland during the dry season, management needs to shift focus from fishing to
environmental conservation and the area included under the protection needs to be expanded.
The influence of nutrients and pesticides has not yet been fully investigated because of the
costs and thus remains a topic for studying.
4. DISCUSSION The region of Messinia and the area around NEO has seen much human development through
history though in recent decades there has been a long period of undisturbed and highly
developed olive agriculture. 70-90% of the catchment areas are farmland and the system of
farmer cooperatives, associated agronomists and irrigation schemes is well established.
Development is now in an interesting phase where tourism and related business is growing
and it could be a turning point for the level of activity in the area. It is also a point where
policy makers have the opportunity of setting the frame for managing natural resources and
where it is important to keep up with development and have good knowledge about the local
environment. This is particularly true in the light of expected climate change.
These discussion sections make an attempt at putting together and interpreting the results and
at addressing the objectives of this study; at evaluating the current state of water resources,
their capacity of accommodating intensification and finally their management (see study
objectives). First however, follows an account of study performance and uncertainties.
Karin Ekstedt
32
4.1 Performance and uncertainty Naturally there are uncertainties inherent in the data and methods that should be accounted for
in analysis and interpretation of the results. Most data issues were addressed in the data and
method’s section. They include for example extremes and missing values in the raw data
series, lack of Q metadata (location, state of the river bed, rating information etc.), and short
time coverage. Treating such short interval of three years only, impairs the assumption of
constant storage in the water balance. Furthermore, the years may not be representative for the
long term average. Gianouzagas for example, covers only one year, which is the wettest year
of the three. A less simplified model would likely give higher accuracy on such short
temporal scale though it would also demand extensive monitoring and data quality. Given
current data availability the simple annual water balance is likely the most reliable approach.
The resultant average annual rainfall in the local catchments (890 mm) falls well within the
range expected from previous regional studies. It is in the middle of the range 800 to 1000
mm estimated for this area and altitudinal range (Loy and Wright, 1972; Ministry of
Environment, 1997). The small difference between the catchments indicates local variability
is small as expected. Larger yearly ranges however show that rainfall varies interannually and
that these particular years may, again, not be representative of the long-term average.
Because no previous studies have been found, the current estimate of discharge and water
balances cannot be compared to observations in similar catchments. Moreover, the issues in
the discharge data of Gianouzagas and Xerias prevent comparison between the catchments.
There are factors that have not been investigated, such as bedrocks, soil types and geological
structures, which could cause spatial differences. Still, the proximity and climatic and
physical similarities between the catchments allow for assuming, in this study, that the
hydrological regimes are similar. Also, the one year in Gianouzagas (HY3) coincides with and
therefore shows consistency with discharge in Sellas. The hydrographs of the rivers (Fig. 3)
furthermore show that the hydrological regimes are somewhat similar in the catchments,
despite the data issues, and often follow variation in precipitation. There are peaks during
winter in both Sellas and Xerias and a simultaneous maximum peak in all three rivers in
February 2012. It is possible that an extreme rainfall event caused this high flow, which might
have wiped out instrumentation or affected the river bed in Gianouzagas judging from its
sudden dip in later observations. This event is not accounted for in the P-data series however.
Lastly, interannual changes in discharge in Sellas follow annual variation in rainfall as is
expected (Fig. 7).
There is uncertainty inherent also in the estimation of ET in local olive agriculture and native
vegetation. As mentioned, the estimation of land use distribution used for calibration is based
on previous regional mapping that may not capture all potentially important local features and
there are only two land use categories. “Native” vegetation represents a range of land covers
that may be different in their evaporative characteristics. Also, precise estimates of ET (as
those from the literature review) are site specific and can rarely be extrapolated spatially
(Fernández, n.d.). This was accounted for however, through scaling the regional average to
the local conditions (see methods). Furthermore, ET resulting from the local water balances
(averaging 540 mm/yr in Sellas) is in the same range as the regional estimations (730 and 410
Local water resource assessment in Messinia, Greece
33
mm/yr in OLV and NV respectively), even if it is comparatively low considering the high
proportion of OLV in the catchment. Indirectly, through the water balance, it indicates that
also the measured Q is in a realistic range.
The land use change modeling next is of course a highly simplified version of a more
complex, dynamic and non-linear response in reality. Uncertainty in the raw data can
moreover propagate also into this analysis. Nonetheless, the simulation gives a robust
indication of the catchment dynamics. The simplicity of the models is adapted to the limited
data availability and the consistency in the results (with expected responses to i) increasing
ET in the new land use, ii) the type of land use transformed and iii) increasing water
exploitation) shows that physical relations are well simulated.
In the interviews and questionnaires finally, two potential sources of uncertainty are linguistic
misunderstandings and the loss of nuances. Smoother communication of course enables
deeper and more extensive discussion as well as collecting a greater number of interviews and
questionnaire responds. Without explanation the mentioning of “university” and “survey”
became intimidating to many. Having no recording device also limits the exact interpretation
after the meetings. Thorough notes were taken however and the texts have been approved by
each respective interviewee. It is apparent furthermore, judging from disagreement between
related rankings and comments, that the questions in the questionnaire were sometimes
misinterpreted. Thus, any interpretation should be made with care.
4.2 The current state of local water resources
4.2.1 Water availability and demands
Abundant water resources, in a regional context, might very well be one of the reasons for
Messinia’s significance through history, and it has certainly contributed to its prosperous
agriculture. It thus appears there has long been a surplus of water for development in the
region. As Mr. Boulolis expressed in the interview, local water resources are considered
plentiful and much water has been exploited for irrigation so far. As mentioned, rainfall here
is much higher than average in Greece and the annual amounts of 890 mm 2009-2012 can
even be further compared to for example Sweden in northern Europe, where the average
rainfall was 620 mm/yr 1860-2012 (SMHI, 2010). Geology in the local area is favorable for
infiltration and storage which, because of high PET particularly in summer, is indeed
important for water availability in this region and climate. Likewise, the Ministry of
Environment (1997) considered water resources and aquifers in this part of the country as rich
and MEECC (2010) describes its supply as “superfluous” in relation to demands under current
conditions.
Altogether, judging from general distribution in Greece and the large proportion of farmland
in the area, the dominating actor in regional and local water consumption is most likely
agriculture. Olive trees consume relatively little water per unit area compared to other crops
(Boulolis, 2012; Zontanou, 2012) though large areas are farmed and up till now water has
been free and withdrawal from local aquifers nearly uncontrolled. Based on independent
numbers provided by Mr. Boulolis, 100-150 mm (11-17% of annual rainfall 2009-2012) is
Karin Ekstedt
34
used for irrigation annually. Again, this is a rough estimation. It is little in comparison to
literature estimations of 180-403 mm/yr, but then these are estimates for irrigated fields and
not necessarily scaled to the catchment. Scaled to the local catchments and normalized over
the total area the literature numbers indicate an extra 200-220 mm/yr is evaporated from local
olive fields compared to native vegetation. This implies that the estimated 100-150 mm per
year of irrigation allows farmers to compensate (within the margin of error for such a coarse
estimate) for the relative excess water lost through olive fields compared to native vegetation
through re-allocation of groundwater on the land surface. It could also show part of the extra
demand is supplied from precipitation and that relatively little irrigation is required, which is
in line with reputation and previous studies confirming this area’s abundant water resources
as described above (e.g. Loy and Wright, 1972; Ministry of Environment, 1997; Zangger, et
al., 1997; MEECC, 2010).
The municipal water supply network also draws upon local aquifers. The largest demand on
the network is from the local business and tourism industry with its hotels and restaurants
(Andrianopoulos and Crikas, 2012), which is indeed an important feature in Greek economy
(e.g. Cudennec, et al., 2007; MEECC, 2010; García-Ruiz, et al., 2011). On the network is now
also Costa Navarino which, counting demands for golf course irrigation, probably is the main
single actor affecting local water resources. The high ambitions of sustainability in its
development, however, have led to several measures for minimizing its influence
(Karakousis, 2012). Domestic uses make the second largest demand on the network and are
also important in local water consumption.
From the questionnaire survey (Qn9, Fig. 9) it appears that the opinion exists of conflicting
interests in the area. Someone mentioned unjust withdrawals in agriculture and someone
brought up “negotiations” with TEMES that gave an unfavorable outcome for the
municipality and local stakeholders (Tab. D1). Importantly, these are subjective views among
individual citizens. With that, the extension (and projected increase) of agricultural
withdrawal does generally create a risk for conflict and competition for water resources with
other uses in the Mediterranean region (Bosello et al., 2013). This implies it could be an
important issue to consider also in local water management.
4.2.2 Capacity of accommodating hypothetical land use intensification
The hypothetical change considered here, the introduction of a highly evaporative land cover
(HYP), can represent any intensification in land use that raises water consumption, in this case
causing ET to approach PET. Countermeasures in land management for such intensification
could include parallel abandonment of (other) agricultural land or general reductions and
savings in irrigation amounts. In Model 1 this is represented by a simultaneous transformation
of olive fields (OLV) to both HYP and native vegetation (NV). Of course the required
reduction of OLV (savings gained) depends on the type of vegetation established afterwards
and full development may take many years. Here, the farmland is assumed to be left to a mix
of native vegetation and its ET is related to regional literature values. Also, it is not relevant in
reality to assume all OLV and irrigation should be abandoned. When the area of NV equals
that of OLV (An/Ao = 1) or earlier already, results start losing their relevance because of
socioeconomic losses (i.e. if HYP is not simply intensification in agriculture).
Local water resource assessment in Messinia, Greece
35
From the three considered scenarios in Sellas, it was found that the area for growing olives
(Ao) must be reduced by 2.1-3.4 units for each unit increase of hypothetical land use, in order
to keep the water balance of Sellas as it is today. This means that at an area of 10 km2, already
up to 34 km2 of current OLV would be lost. Also, assuming all olive agricultural water
consumption is stopped (Ao = 0), as little as 22% (19.1 km2) of the total area can be covered
by HYP in Sellas (if its ET is close to the potential). Thus, intensifying the land use in the area
to this extent is difficult without affecting the current water balance. This is likely because of
the high PET that causes vegetation to consume much water if provided. It is clear in the
model accordingly that impacts depend greatly on the ET of the new land use, particularly the
larger the development (compare the scenarios of increasing ET). Numerous studies point
accordingly to the decisive influence of ET on water resources during land use changes
(Brown, et al., 2005).This implies not only the area transformed, but also the land and water
management applied, are important. Timing and type of irrigation as well as type of
vegetation might influence capacity for example. The approach aimed for by TEMES, using
meteorologically controlled irrigation systems and low-evaporative grass types for their golf
courses (which create intensification in land use), is seemingly an effective method for
reducing the hydrological impacts.
Increasing the total water consumption above today’s level, i.e. exploiting a higher proportion
of discharge, naturally allows for considerably larger areas to be covered with HYP (Model 2).
Of course a complete exhaustion of the water resources for irrigation is not realistic - there are
competing interests for example for human and ecological needs, supply and demands are
seasonally unbalanced and not all water is exploitable for technical, economical or quality-
related reasons - yet it demonstrates what extents are theoretically possible. Whether OLV or
NV is transformed to HYP is a matter of the specific situation. OLV normally covers more
attractive and accessible land for development plus abandonment results in water savings
(compare case 1 and 2). Exploiting NV however, prevents the loss of fertile farmland.
At this scale, evapotranspiration of the new land cover has substantial influence. In scenario C
(ETh is 1250 mm/yr which correspond to PET) no more than 59% of the total area is possible
while in scenario A (ETh is 900 mm/yr) already the entire catchment can be exploited; with a
surplus of water (P now exceeds ETh). Thus, if evapotranspiration (again) is kept low,
increased water withdrawals could enable substantial intensification while still satisfying
other water requirements in the area (i.e. if feasible and desired in land use management).
Also, considering the current levels of consumption this implies there is a present (annual)
surplus of water available for development (inherent in Q). This is only true however, if the
excess water is accessible and if other demands are small and satisfied. It is unclear how
much of the “excess outflow” in the rivers that can be further exploited considering the
reservoirs already constructed by TEMES. Also, it would require additional infrastructure for
storage because of the uneven seasonal supply. It has been shown that reservoirs affect river
systems considerably and that functioning is sensitive to hydrological alterations brought for
example by climate change (García-Ruiz, et al., 2011), which could be notable in the region
(e.g. IPCC, 2007b; MEECC, 2010; Trondalen, 2009). All in all this implies there is theoretical
Karin Ekstedt
36
capacity for increased water consumption and land use intensification in the local area but
then it may not, necessarily, be achievable in reality.
4.2.3 Is there shortage or surplus of water resources and are current levels of consumption
sustainable?
If there is shortage or surplus of water depends on the balance between supply and demand.
As described above local water resources in the area are considered (and are) comparatively
rich and there is considerable surface outflow from the basins at today’s level of consumption.
Thus, there should be a surplus of water in the local area. On the other hand, Mediterranean
water resources are bound by climatic seasonality. Not only is annual PET high (compare
1240 mm to 200-600 mm in Sweden 1961-1990 (SMHI, 2009)) but as it peaks during
summer, there is essentially no rainfall. At the same time, agriculture and tourism are two of
three main local consumers of water, and their demands are greatest during the high summer
season. This suggests, as is typical in coastal regions around the Mediterranean (e.g.
Cudennec, et al., 2007; Giorgi and Lionello, 2008; MEECC, 2010; García-Ruiz, et al., 2011),
that there is a seasonal imbalance in supply and demand - which brings an apparent shortage
of local water resources during the summer season. This matter is also confirmed by the
managers at DEYAP and in several questionnaire comments (Tab. D1) where many point
specifically to summer deficiencies. Answers to Qn2 also show that water availability
commonly is a limiting factor in every-day operation of local stakeholders.
Storage in the aquifers allows for winter excess to be extracted during the dry summer season
and this, again, is what enables extensive agriculture. As it is, irrigation withdrawals go far
back in time and agriculture is now close to its maximum extent judging from its domination
in the catchments. The question is then if supplies and demands are balanced in the long-term
and if consumption is sustainable. That might very well be the case considering the annual
surplus addressed above, and the opinion seems to be that exploitation has not yet affected the
reservoirs. Still, there appears to be signs (see interview with Mr. Boulolis) of declining
ground water tables as well as deteriorating quality with both pollution and increasing salinity
in shallow wells (not scientifically confirmed). In the old wells near Gialova, salinity is
almost too high to pump for drinking water and in the questionnaire (Qn3), majority of those
surveyed feel water availability has decreased in recent years.
Thus, based on unofficial sources it appears local ground water resources are experiencing
(increasing) pressure. Whether this is because of over-exploitation or a result of climatic
variability or change is difficult to judge but it may point to a state of non-sustainability.
Several studies stress the sensitivity of coastal aquifers in the Mediterranean region, the over-
exploitation, the lowering of ground water tables and increasing risk of salt water intrusion
(e.g. Cudennec, et al., 2007; MEECC, 2010; García-Ruiz, et al., 2011; Mazi, et al., 2013).
This implies that the issue of sustainability requires attention in both research and
management, even if more extensive studies and monitoring are required to objectively
determine the actual state in the local catchments.
Local water resource assessment in Messinia, Greece
37
4.3 Local water management The setup of water management in the municipality of Pylos-Nestor was described through
the interview with Andrianopoulos and Crikas (2012). Since the municipal population
exceeds 10 000 the management is arranged through a DEYA as is common in Greece and its
main challenge is apparently also similar to what is typical in the country: the balancing of
increasing socioeconomic development with a risk of decreasing water availability. Here
follows an evaluation of water management in the local area, based on literature and on
findings in the study.
There are several strategies for adapting to increasing water stress, comprising both supply
and demand side measures. Supply-side measures include water recycling and consideration
of alternative sources (e.g. Safarikas, et al., 2006; IPCC, 2007b; García-Ruiz, et al., 2011;
Bosello, et al., 2013). In the local area this could correspond to building extra surface water
reservoirs for irrigation in order to redistribute pressure from local aquifers. This has been
done by TEMES and is considered by DEYAP together with ideas of desalinization. Based on
previous reasoning there is capacity for increased withdrawals still it may not be
straightforward in practice. It could also mean exploring other locations for ground water
exploitation, as is already underway. DEYAP is working on improving the drinking water
supply and waste water treatment which is important for securing human requirements. As
mentioned however, the issue of aquifer sustainability must be considered in such
development.
Demand-side measures include reduction of leakages, water conservation and water prizing
(e.g. Safarikas, et al., 2006; IPCC, 2007b; García-Ruiz, et al., 2011; Bosello, et al., 2013).
Degraded networks are a common issue in Greece overall (Tsagarakis, et al., 2003) and local
voices claim it is indeed an issue in the study area (Tab. D1). Thus, this might be an issue to
address in local management. It is common in Greece also that water prices are set too low.
Tariffs are often in conflict with the business sector and domestic expenses, and they are
usually set merely to cover the running costs of the DEYA (Safarikas, et al., 2006). In this
context the strong institutional framework is important to set clear guidelines and distribute
responsibility (García-Ruiz, et al., 2011; Bosello, et al., 2013).According to Mr.
Andrianopoulos and Mr. Crikas water pricing is one of the strategies considered at DEYAP to
prevent water over-consumption and deductions in this study imply this is indeed an
important tool and measure.
There are some contrasting views on the degree of integration of local stakeholders in the
management processes of DEYAP. The commercial sector and local citizens are represented
in the board of DEYAP, planning and actions are accounted for in yearly information
distributed to the households and there is seemingly dialog and cooperation with the
important actor of TEMES. Most of those asked in the questionnaire accordingly seem well
informed about regulation (Qn4) and more than half feel they have insight in regional water
management (Qn6). When it comes to the possibility of local stakeholders and actors to
participate and become involved in the process however, responds are negative (Qn8) and
answers to Qn7 show that confidence in local management is low. The work and influence of
the board representatives mentioned have not been investigated in this study yet, based on
Karin Ekstedt
38
motivation in previous studies (e.g. Tsagarakis, et al., 2004; Bosello, et al., 2013), it could be
that both managers and stakeholders could benefit from greater outreach and a more open and
integrative process. This would be the goal while implementing the EU WFD also.
As was described in the introduction the main responsibility for strategic environmental
planning is on national and regional (prefectural) levels yet DEYAP governs local
implementation. According to Mr. Andrianopoulos and Mr. Crikas much attention is given to
environmental needs, for example through supporting preservation work in Gialova lagoon.
There are evident issues remaining in management of this wetland however (Maneas, 2012;
HOS, 2013). Impression is there is little consideration and efforts made in agriculture and that
there is only limited control of, for example, the influence of freshwater withdrawals,
pesticides and nutrients both here and in the overall aquifers. Most of those asked in the
questionnaire survey believe water resources are sufficient to protect environmental values
(Qn10) yet there are critical voices particularly aimed at unsatisfactory management rather
than limited water quantities. Thus, based on personal communication, there might be a need
for increased environmental consideration in water management and naturally, upstream
measures are equally important as site specific remediation.
Water management in agriculture is particularly important considering its socioeconomic
importance but also its possible influence on local water resources. Future trends are difficult
to predict and will depend greatly on external factors (Nainggolan, et al., 2012). It could be
that stable or growing markets continue to cause intensification in farming or that decreasing
water availability causes water prices to escalate, rendering OLV non-profitable. OLV could
also be gradually transformed in favor of other crops having different water demands and/or
better commodity prices. Given the profound establishment and culture of olive farming in the
region however it will likely remain dominant. Regardless, there is a justified need to control
withdrawals, both for preserving the aquifers and for securing long-term access to water.
Deduced from Qn5 in the questionnaire, farmers are more concerned than average citizens
regarding future water limitation and even more than regarding current limitation in Qn2
(though these difference are small). Closer regulation at prefectural level is clearly in progress
and local farmers are apparently working additionally with agronomists to improve water
management. Markets for ecological farming are furthermore growing judging from emergent
interest of the services and products of companies such as Nileas.
In the end, even if local water resources are currently considered “superfluous”, short-term
unsustainability in ground water exploitation is a common issue in the Mediterranean and
Greece. Indeed, given the projected shift in the balance of supply and demand, MEECC
(2010) has predicted a reduction of also this area’s water surplus. Current management may
be critical for long-term sustainability and future trend predictions should be considered also
here, despite large uncertainty. After all though, it appears local water resources are being
actively and increasingly cared for and management has the potential of being sufficient to
address increasing anthropogenic and climatic pressure given that i) necessary measures are
taken to keep up with development and prevent over-exploitation, ii) environmental values
are sufficiently administered iii) agricultural water consumption is controlled and iv) local
stakeholders and citizens are involved and active in programs for preserving water resources.
Local water resource assessment in Messinia, Greece
39
4.4 Further studies There are several studies that highlight the importance of extensive research regarding future
water supplies, at the local as well as sub-continental scale (e.g. Cudennec, et al., 2007;
Giorgi and Lionello, 2008; García-Ruiz, et al., 2011; Bosello, et al., 2013). Often pointed out,
research should be coordinated in interdisciplinary teams with much cooperation among
scientists and knowledge should be communicated to stakeholders and policy makers. With
the establishment of NEO, policy makers in Pylos-Nestor now have a unique opportunity of
taking advantage of local research and adjusting environmental management strategies. To
enable studies however, it is crucial there is sufficient monitoring and data available. This is
probably the most common key point in the studies mentioned, and perhaps the most
important outcome of this study. To enable local hydrological studies there is a strong need of
improving data quality and exchange, particularly of discharge gauged in the local rivers.
Researchers need more control of the measurements and uncertainty needs to be minimized.
Thus, better communication and exchange between NEO and TEMES, who are conducting
the measurements, should be sought.
Based on issues identified in this study some topics could be suggested for further research.
For example, more detailed mapping of local land use distribution could enable more precise
hydrological modeling. Focus could naturally also fall on investigating future scenarios of
both anthropogenic and climatic changes in the local area, and their influence on local water
resources. Long-term trends in water tables could be evaluated for investigating sustainability
and finally, further study could assess the water quality impacts of pesticides and nutrients
used in local agriculture. Freshwater availability is indeed important in the daily life of local
stakeholders and actors active in the catchments of Sellas, Gianouzagas and Xerias (Qn1). It
is, hence, of importance for proper management and for continuous monitoring and research.
Karin Ekstedt
40
5. SUMMARY AND CONCLUSIONS Summarizing the current state of local water resources it can be concluded that, in a regional
context, they are indeed comparatively rich. Rainfall is higher than average in Greece, there is
considerable outflow from the basins and geology is favorable for ground water recharge.
This has allowed for extensive agriculture and rich nature, which is now also attracting
considerable tourism and possibly other socioeconomic development. On an annual basis
there is a net surplus of water in the local area. Still, considering the temporal imbalance of
supply and demand - especially with agriculture and tourism being the principal water users -
there are seasonal shortages that based on this study do affect local actors.
Furthermore, because of high annual potential evapotranspiration, the water system is
sensitive to intensification in land use. Modeling shows that unconsidered water consumption
requires large countermeasures not to affect the water balance but also that proper
management, keeping evapotranspiration down, may render large capacity of intensification if
withdrawals are increased. The question is however, if such development is feasible in the
perspective of i) accessibility, ii) human and ecological needs and iii) sustainability. There are
signs showing the current situation could be non-sustainable already - either because of over-
exploitation or climatic factors. Reliable conclusions on the subject however, call for more
detailed studies and monitoring. Regardless, any development requires careful management
especially in the light of increasing climatic water stress.
The municipal water management in the area appears to be well established and there are
several measures planned and considered for improving water security at DEYAP. All in all
there is potential for accommodating increasing anthropogenic and climatic pressure given
sufficient measures are taken. Such identified in this study include increasing integration of
local stakeholders, maintaining environmental values and controlling agricultural water
consumption. Also, studying and understanding the hydrological system is fundamental - and
adequate monitoring and data availability crucial. Therefore, as a main implication of this
study, there is a need for data improvements, especially in terms of discharge. In the end,
freshwater availability is, irrespectively and decisively, integral to all ecosystems and to all
aspects in human societies.
Local water resource assessment in Messinia, Greece
41
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Karin Ekstedt
46
a.
Oliv
e agricu
lture (O
LV
)
A
uth
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nd
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r L
oca
tion
M
ethod
S
tud
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rees/ha
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ET
1
Fern
ánd
ez, et al., 20
06
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F
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56* P
enm
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onteith
1971
-200
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286
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45
605
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S S
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1983
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2
100
55
2
13
33
648
3
Detto
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inien
-
- -
- 1
000
560
4
Detto
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87
Sard
inien
-
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- 1
200
620
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Fereres, 1
99
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- -
- 1
400
750
6
Fern
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- 2
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Palo
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-
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588
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55
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18
Testi, et al., 2
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6
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1998
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100
59
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33
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19
Testi, et al., 2
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6
S S
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1998
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300
59
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33
10
25
20
Testi, et al., 2
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6
Califo
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1998
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30
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1998
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END
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FOR
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LV A
ND
NV
T
ab
le A1: T
he stu
dies rev
iewed
for estim
ating E
T o
f a. OL
V an
d b
. NV
: auth
or(s), y
ear of p
ublicatio
n, lo
cation, m
ethod
, stud
y p
eriod
, trees/ha o
r
veg
etation
typ
e, estimated
P, P
ET
and
ET
. So
me stu
dies rep
ort m
ore th
an o
ne resu
lt from
vary
ing ex
perim
ent set-u
ps an
d th
erefore featu
re more th
an o
nce.
Wh
ere data is m
issing th
e valu
es could
either n
ot b
e ded
uced
or th
e full article w
as not av
ailable. A
num
ber o
f abb
reviatio
ns are u
sed to
simp
lify th
e table:
EC
= ed
dy co
varian
ce measu
remen
ts, RE
FE
B =
Reg
ion
al Evap
orativ
e Fractio
n E
nerg
y B
alance m
ethod, R
S =
remo
te sensin
g, S
= so
uth
ern, S
A =
scenario
analy
sis, SC
= sclero
ph
yllo
us, S
F =
sap flo
w m
easurem
ents, S
td =
standard
dev
iation, S
W =
south
western
. Th
e references are in
clud
ed in
the referen
ce list
of th
e main
repo
rt mark
ed w
ith asterisk
s.
Local water resource assessment in Messinia, Greece
47
§T
ab
le A1
cont.
b.
Nativ
e veg
etatio
n (N
V)
A
uth
or a
nd
yea
r L
oca
tion
M
ethod
S
tud
y p
eriod
V
egeta
tion
typ
e P
P
ET
E
T
1
Krish
nan
, et al., 20
11
Arizo
na
EC
+R
S
2004
-2007
G
rassland
(post-fire)
475
-
29
7
2
Krish
nan
, et al., 20
11
Arizo
na
EC
+ R
S
2004
-2007
G
rassland
(un
burn
ed)
340
-
22
5
3
Ryu
, et al., 20
08
Califo
rnia
EC
2001
-2007
G
rassland
565
9
61
31
9
4
An
derso
n, et al., 2
01
2
Califo
rnia
EC
2007
-2008
O
ak/C
onifer
515
-
43
0
5
An
derso
n, et al., 2
01
2
Califo
rnia
Priestly
-Tay
lor m
odelin
g
2008
-2009
O
ak/C
onifer
322
>
13
00
65
5
6
An
derso
n, et al., 2
01
2
Califo
rnia
RE
FE
B +
RS
2008
-2009
O
ak/C
onifer
322
>
13
00
37
1
7
Go
uld
en, et al., 2
01
2
Califo
rnia
EC
+ R
S
2003
-2011
S
avan
na-e
verg
reen o
ak/p
ine
984
5
54
42
9
8
Bald
occh
i, et al., 20
04
Califo
rnia
EC
2001
-2002
G
rassland
525
5
85
29
5
9
Bald
occh
i, et al., 20
04
Califo
rnia
EC
2001
Oak
/grass
494
8
69
38
1
10
Gould
en, 1
996
Califo
rnia
Can
op
y lev
el and S
F.
1989-1
990
SC
everg
reen trees
449
- 443
11
Go
uld
en, 1
99
6
Califo
rnia
Can
opy lev
el obs +
SF
1989
-1990
S
C ev
ergreen
, large sh
rubs
449
-
57
0
12
Lew
is, et al., 20
00
Califo
rnia
Water b
alance
1981
-1997
O
ak w
oo
dlan
d
708
1
916
36
8
13
Bald
occh
i and
Xu
, 20
07
Califo
rnia
EC
20
03
-2004
O
ak w
oo
dlan
d
558
1
089
35
8
14
Joffre an
d R
amb
al, 199
3
Sp
ain
(site 1)
Water b
alance
1984
-1985
O
ak w
oo
dlan
d
895
-
51
7
15
Joffre an
d R
amb
al, 199
3
Sp
ain
(site 2)
Water b
alance
1984
-1985
O
ak w
oo
dlan
d
797
-
48
4
16
Joffre an
d R
amb
al, 199
3
Sp
ain
(site 3)
Water b
alance
1984
-1985
O
ak w
oo
dlan
d
939
-
55
7
17
Infan
te, et al., 2003
Spain
S
F
1993-1
994
Oak
wo
odlan
d
720
1419
191
18
Tiro
ne, et al., 2
00
3
Italy
EC
-
Oak
woo
dlan
d
- -
43
2
19
Dav
id, et al., 2
00
4
Po
rtugal
SF
1996
-1998
O
ak w
oo
dlan
d
665
1
760
41
4
20
Avila an
d R
oda, 1
99
0
NE
Sp
ain
"Watersh
ed ap
pro
ach"
(6 y
ears) S
C b
road
leaved
8
57
-
41
5
21
Lu
o, et al., 2
00
7
S
Califo
rnia
EC
tow
er 1997
-2003
S
hru
blan
d
349
-
36
1
Av
erag
e
596
1
144
41
0
Std
212
5
11
11
2
*S
ee: Alle
n, R
.G., P
ereira, L.S
., Raes, D
. and
Sm
ith, M
., 199
8. C
rop
evapo
tran
spira
tion
- Gu
idelin
es for co
mp
utin
g cro
p w
ater req
uirem
ents - F
AO
Irriga
tion
an
d d
rain
ag
e pap
er 56
. [pd
f] Ro
me: F
oo
d an
d A
gricu
lture O
rgan
ization o
f the U
nited
Natio
ns (F
AO
). Availab
le at:
http
://ww
w.fao
.org
/do
crep/X
04
90
E/X
049
0E
00
.htm
[Acce
ssed 7
January
20
13
].
Karin Ekstedt
48
APPENDIX B: THE QUESTIONNAIRE
Survey on water resources management
Responsible: Karin Ekstedt (+46 73 402 16 36)
Background information
This survey is part of a master thesis in the program of “Hydrology, Hydrogeology and Water
Resources” at Stockholm University in Sweden. The study objectives are to quantify a basic water
balance and to assess water resources management in the region of Navarino. Individual answers in
the questionnaire will not be published but compiled and presented as statistics and anonymous
statements. Participation is greatly appreciated!
Personal information
Ranking questions
Please rank the following issues on a scale from 1-10 where applicable.
Feel free to comment and explain your answers (Greek is okay)!
Do not
agree Agree fully
1. Access to water is important in my daily life/work
Comment:
2. Water availability limits my daily life/work
Comment:
3. In recent years, water availability has…
Comment:
Name (optional):
Contact info (optional):
Gender: male female
Age:
Home town/district:
Occupation:
1 2 3 4 5 6 7 8 9 10 No opinion /
Do not know
PLEASE TURN OVER
increased been
unchange
d
decreased Do not
know
Local water resource assessment in Messinia, Greece
49
Do not
agree Agree fully
4. I am well informed about rules and regulation regarding the use of water for my daily life/work
Comment:
5. Water availability may limit my daily life/planned work in the future
Comment:
6. I am well informed about water management in the region and know how it is handled
Comment:
7. Water resources are well treated and managed in the region/basin
Comment:
8. The water policies and management plans are transparent and allow for involvement of local
stakeholders/actors
Comment:
9. There are no conflicting interests for water use in the region/basin
Comment:
10. The current water resources are enough to protect the environment and the ecosystems in the
region
Comment:
Thank you for your participation!
Other comments:
1 2 3 4 5 6 7 8 9 10 No opinion /
Do not know
Karin Ekstedt
50
0%
20%
40%
60%
80%
100%
0 5 10 15 20 25
% o
f A
t
Ah (% of At)
APPENDIX C: RESULTS OF MODEL 1 IN GIANOUZAGAS The response of An/Ao to Ah in Gianouzagas simulated in Model 1 is similar to that in Sellas
(Fig. 8). Naturally, Gianouzagas has a different initial ratio of An to Ao compared to Sellas
(from Tab. 1 in Data and Methods; Site description: 26/74 = 0.35 and 11/89 = 0.13
respectively) and it has a somewhat higher rate of decrease in Ao with one unit of Ah. For
example, in scenario C ΔAo/ΔAh = -3.8 in Gianouzagas compared to -3.4 in Sellas. The
difference however, is considered insignificant in this context and comparison and similarity
support the results of Model 1 in Sellas.
Figure C1: 0 < An/Ao < 2 as a function of Ah introduced in the catchment of Sellas under the three ETh
scenarios (A = 900, B = 1075 and C = 1250 mm/yr of ETh) (upper chart) and a stacked area diagram
showing the change in distribution between Ao (white), An (checked) and Ah (black) in scenario C
(lower chart). The same graph for Sellas only, is shown under Results; Hypothetical land use
intensification; Model 1; Fig. 8.
0
0,4
0,8
1,2
1,6
2
0 5 10 15 20 25 30
An/
Ao
Ah (% of At)
A
B
C
Local water resource assessment in Messinia, Greece
51
APPENDIX D: COMMENTS TO THE QUESTIONNAIRS Table D1: Summary of the written and oral (in italics) comments given in connection to the
questionnaire (Qn = question). No names are given in order to maintain anonymity.
Translation from Greek was made by Victoras Plevrakis.
Qn Comment
1
It’s impossible to operate without water, most people don’t know of water importance and for example
do not close tap while shaving/showering
Need it for all things
2
Do not drink from the tap
During dry periods
During summer especially
The water in the summer season is significantly less, summer season decreases, sometimes no water
It makes everything very difficult
Tap water is from ground water, do not drink because pipes are bad, but they do drink in Athens
Do not drink tap water because of salinity, bad taste
Net/pipes are from asbestos, ca. 60-70 years old, degrading, it is 20 km from source to city, people buy
water to drink
Some days there is no water
Some years ago water was periodically turned off to save water
3
Water availability decrease due to less rain and gw withdrawal (illegal)
Waste of water, water not drinkable so they don't care, wash cars + streets, irrigate gardens
Due to limited rainfall and bad management practices
Most probably decreased - does not rain enough
Due to climate change less rains and big irrigation need
Have plenty of resources in Petrochori (village between Romanos and Gialova Lagoon)
4
Everybody must be
Different info from different sources, is not from here (lived here for 3 years), no info by post
Based on studies and working experience (answer: 9)
It is common that people with separate waste water tanks cast off used water down the streets at night
to clean the path and to avoid the high costs of emptying the tanks
5 I wouldn't like that
Water is the life
6
But even the others must be
I am well informed but not certain that everyone does what he says
Government and municipality do not involve locals, no integrated management
No info to local citizens about water management and quality
7
Absolutely not, they make quality tests but still not okay
There can be better water resources management in order to save more and not waste it + can use and
save more water
I totally disagree because too much water is spent without being used
Water management should be updated according to 2000160 EU directive
No they are not
Water management is not god
8 Absolutely not
No information is given to citizens about water management and quality
9
Unfortunately there are a lot: olive groves, ground water for irrigation, nobody pays, everyone help
friends to get more than others
There are, and to be more precise in the case of the large touristic resort “Costa Navarino” the
negotiations that took place didn’t have the optimum outcome for the municipality and the local people
(farmer in Chora)
10
Yes, but they must be administrated as well, have water but not handled properly
No, need more water for basic needs
In my opinion it is a matter of water management and not water quantity
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