DaNUbs Project results
Lessons learned for Black Sea Water Quality Mangaement
Helmut Kroiss, Matthias Zessner, Christoph Lampert Institute for Water Quality, Ressource and Waste
Management Vienna University of Technology
Varna meeting June 2005
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Eutrophication abatement in Black Sea Coastal areas
Some basic relationships for better understanding the role of nutrients
(N, P, Si)
Algae productionNatural sources
N
P + light + CO2 organic solids
sediment
O2 (surface)
organic matter + O2 CO2 + H2O + biomasse
Breakdown of organic matter
food chain
fishery release of N and P to water
removalto atmosph.(DN)
transport and storage with water
fixation in sediments (long term)
anthropogenicsources of
N and P
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Mass flow of nutrients N and/or P [Mg/a] represents a potential for primary production in rivers and the sea
Concentration of one essential “nutrient” and/or solar energy availability limits growth (use of the potential)
ratio of «nutrients», fishery and solar enery availability infuence competition between species and natural food chaines.
Human activity leads to import of foreign species (jelly fish) and waste (water) discharges (new substances or inhibitors)
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Data quality assessment and related problems
Data interpretation
The basic data for all considerations regarding the role of nutrient fluxes are concentrations in the water and flow.
The most reliable data are those for dissolved (inorganic) nutrients.
Data are much less reliable in regard to particulate and
organically bound nutrients.
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Data interpretation
The measured values are already the result of the following processes and their related history:
• Natural nutrient input• Anthropogenic input• Primary production (sunlight, climatic conditions)• Release of nutrients from breakdown of organic
solids (including denitrification)• Transport phenomena, intermediate storage• “final” storage in sediments (e.g. deep sea)
Data interpretation
All these processes are subject to strong variations over time (day, season, year, decades) and are strongly influenced by specific local and regional conditions.
There are much less reliable data on particulate nutrient compounds. Their interpretation is even more difficult than for the dissolved compounds.
The basic consequence of these statements is:
Interpretation of measured concentrations and calculated fluxes (loads) without understanding the processes involved is very limited and can be even completely misleading
Specific local and regional conditions Natural conditions:• Geology• Morphology (e.g. slope)• Climate (temperature, precipitation, latitude)
Anthropogenic influences (past decades, actual, future)• Agriculture
Crops Volume of production Animal production (volume and density) Practice (fertilizing, manure handling) Water and waste water management (municipal, industrial,
storage) Air pollution (incineration, traffic)
plants
animals
Specific local and regional conditions
Natural:• Geology• Morphology (e.g. slope)• Climate (temperature,
precipitation, latitude)
Anthropogenic:• Water management• Air pollution abatement • Agricultural practice
quality
quantity
land use
Scenario developmentand assesment for different
options of „policy“
Historic development of policy, economy, technology, science
Specific local and regional conditions
Using the information about the • natural conditions and • knowing the relation between the natural conditions, the • anthropogenic influences and • their effect on the nutrient fluxes
different scenarios can be developed which include economical, political and technological tools.
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Management tools
• After an assessment of “bearable nutrient loads for WBSC” a decision has to be made for the implementation of a combined approach strategy including – precautionary principle (legal framework on
minimum criteria, e.g. UWWD, good agricultural practice, enhanced by economical incentives, etc.)
– environmental quality criteria for additional measures based on cost effectiveness
Assessment of the actual state of WBSC Strong improvement during the last decade
Indicators for this improvement are:
• Anaerobic conditions in sediments (anoxia) have nearly disappeared
• Marked increase of number of macrobenthic species
• Algae growth is phosphorus limited (in summer, in winter probably light limited)
• Rare algae blooms (similar to the 1960ies)
• Red algae in NWBS bottom area in depth up to 40 m
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
20
22
24
26
28
30
32
34
36
38
40
1988 1996 1999 2000 2002
Period
Nu
mb
er
of
sp
ec
ies
Number of macrobenthic species in front of the Danube delta showing an increase of species since 1996 (10 stations on 3 transects off Constanta) data from C. Domitrake.
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
• The anaerobic conditions at the bottom of WBSC, clear indicators of eutrophication, have nearly completely disappeared. The situation is close to the sixties now.Only the fish stock is still out of balance. This is mainly a result of inadequate fishing.
• P is the limiting factor for eutrophication of the Black Sea. Therefore efforts should continue to reduce P emission.
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
A B
A. SeaWiFS Satelliten Bild des Westlichen Schwarzen Meeres von 7 May 2000. B. Summenbild (ca. 800 Satellitenaufnahmen 1998-2002) des westlichen Schwarzen Meeres mit (rote Linien) Ausdehnung gemäßigter und intensiver Algenblüten wie sie in den 1980ger Jahren beobachtet wurden (nach Zaitzev 1992)
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Geringe Ausdehnung der Eutrophierungszone - südlich des Donau Deltas sowie niedrige Nährstoffkonzentrationen in unmittelbarer Nähe des Eutrophierungsgebietes im September 2002. .
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
January 1998-2003
February 1998-2003
March 1998-2003
April 1998-2003
May1998-2003
June 1998-2003
July 1998-2003
August1998-2003
September 1998-2003
October 1998-2003
November 1998-2003
December1998-2003
Monatliche Mittelwerte von mittleren (> 1.38 mg m-3) und hohen (>5 mg m-3) Chlorophyllkonzentrationen im westlichen Schwarzen Meer aus SeaWiFS Satelliten Aufnahmen (Davidov 2004).
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
1
2 3
200 m
29.0 30.0 29.0 30.0
43.8
44 .2
44.6
45.0Danube
September 1996
80
7060
50
606
0
60
60
50
50
40
30
Danube
September 1999
100
100
120
120
120140140
80
80
29.0 30.0
September 2003
Danube
100
100
100
90
90
80
80
70
Sauerstoff arme Gebiete im Flachwasser des nordwestlichen Schwarzen Meeres von 1974 bis
1983 und die Verbesserungen der Sauerstoffverhältnisse in Bodennähe zwischen 1996 und 2003.
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Im September 2004 wurden vor der ukrainischen Küste wieder größere Bestände der Rotalge Philophora beobachtet.
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
The improvement is caused by reduced nutrient inputs by Danube River.
Transported phosphorus loads are reduced to about 50 % as compared to the situation around 1990.
Phosphorus is the limiting nutrient now for algae growth which seems to be the main reason for improvement of marine ecology in the WBSC.
Nutrient transport from catchment to Black Sea
Actual situation
• P discharge to WBSC has decreased by about 50% compared to the early 1990ies, the situation is comparable to the 1960ies
• N discharge has markedly decreased, probably by about 30%, data consistency makes problems
• Slow trend towards lower nutrient loads from Germany and Austria
A strong decrease in nutrient point and diffused emissions in Eastern Danubian Countries (EDC), but
an increase can be anticipated due to an increasing use of market fertilizers to reach economic sustainability in agriculture
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Deviation load calculated to load observed for 1998-2001:
20% for DIN
Assumptions:
BG & 50‘s: 50%
1975: 50%
1980 to 90: 30%
1995 to 99: 20%
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Deviation load calculated to load observed for 1998-2001:
29% for TP
Assumptions:
50‘s: 60%
1975: 50%
1980 to 90: 40%
1995 to 99: 30%
Nutrient transport from catchment to Black Sea
Actual situation
The main causes for this positive development are:
• Economic crisis in EDC countries since 1989
• Change of agriculture from economically driven production to nutritional survival of the population, closure of the large animal production plants and of fertilizer industry (market fertilizer application close to zero)
• Use of P free detergents in D, A, and increasingly in EDC
• N and P removal at municipal treatment plants in D, A, CZ
• Improved agricultural practice
(i) MONERIS
(ii) DWQM
(iii) DDM
(iv) Shelf Model
(i) nutrient balancesagriculture, nutrition, diffuse
pollution etc.
(ii) transportin rivers
(iii) Effects onBlack Sea
Emissions to surface water
In stream transports, fluxes to Delta
Fluxes to Black Sea
Sources, pathways and stocks in the catchment
Critical nutrient loads
(i) Handbook fornutrient balances
(ii) scenarioevaluation
Processunderstanding
Legend:
Model Strategicplanning
Results
(I.) (II.) (III.)
Solutions for nutrientmanagement
MODELLING
s
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Schematic of model simulations connectivity and data flow
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Regional differences of nitrogen emission via groundwater to surface waters
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Regional differences of back ground loads in the Danube Basin
Wastewatermanagement;
22%
Background; 25%
Agriculture; 45%
Combustion and traffic; 8%
Sources of nutrient emissions 1998-2000 into the Danube
Total Nitrogen
Background
Background;9%
Combustion and traffic; 3%
Agriculture; 43%
Total Posphorus
Sources of nutrient emissions 1998-2000 into the Danube
Wastewatermanagement;
45%
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
The current relatively low discharges of N and P to the Black Sea are to a certain degree a result of the economic crisis in the former communist countries (EDC) resulting in:
a dramatic decrease of the application of mineral fertilizers,
the closure of large animal farms (agricultural point sources) and the
closure of nutrient discharging industries (e.g. fertilizer industry).
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
} 2.21.1
The TP load in the Danube in the period 1983-1987 was 2.2 times higher than in the 50‘s.
The present TP load is only 1.1 times higher than in the 50‘s.
Without Iron Gate the present TP-load would be 1.5 times higher than in the 50‘s
Iron Gate
Driving forces for N, P emissions to water system in agriculture:
a: Anthropogenic
• Fertilizer management in plant production
• Production of animal protein and fat (milk, meat, eggs)
• Soil quality management, erosion abatement, etc.
• Economic competitiveness of agricultural products
b: Natural
• Soil geology
• Precipitation (amount, distribution)
• Climatic conditions
• Slope
• Residence time in groundwater
Driving forces for transport and losses:
• Denitrification potential mainly from source to medium size rivers with strong emphasis on processes in soil and ground water (residence time) and interaction between ground and river water (littoral areas).
• Large rivers (including wetlands along these rivers and the delta) have only little influence on N transport and loss.
• Erosion together with overfertilisation contributes to transport of particulate nutrient loads, The role of particulate nutrient loads in the Black Sea Coastal Area may depend on the easily accessible nutrient loads as primary eutrophication potential. In case of anoxia at the sea bottom, nutrient release from the sediments represents an unpredictable additional potential for eutrophication.
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Scenario calculationsEntwicklung der Phosphoremissionen im Donaueinzugsgebiet
0
20
40
60
80
100
120
140
1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 1 2
rive
r lo
ad
s a
nd
em
issi
on
s [1
00
0 tP
/a]
diffuse emissionsindustrial and agricultural point sourcesmunicipal point sources
scenarios:1: UWWD without P-removal2: UWWD with P-removal
Danube river load
Conclusions
• Good data quality and adequate data availability are basic requirements for the development of rational water quality management strategies.
• Understanding the transport, storage and transformation processes of “pollutants” from their source to the receiving sea and their effects on aquatic ecosystems (and other environmental compartments) is necessary for data interpretation
• Mathematical modelling is a useful tool :• to improve the application of our knowledge and
experience (understanding) to answer specific questions for complex systems
• to validate our knowledge and/or evaluate data quality
Conclusions
• Model results can never be “better” than our understanding and the quality of the data we use for calibration
• Validation of models for complex systems becomes less reliable the better the model simulates reality i.e. the more processes (parameters) are included
• Black Sea Quality management strategy can never be developed from Black Sea data alone, even monitoring program is extended and improved.
• Pollution has to be controlled as close to the sources as possible. For this statistical database have to be exploited using mass balance methodology.
Conclusions
• Reliable long term historic data from catchment and Black Sea are necessary for the interpretation of the actual state
• Climatic conditions (including climate change) play a decisive role for transport and transformation of all “pollutants”
• A great variety of economic and political tools to influence on the emissions and to avoid pressure on the environment are available. They have to be assessed according to their cost effectiveness under the different specific regional circumstances.
• Water quality management on a catchment scale needs a long lasting strategy for sustainable development with a prospective of about 30 years for stable success.
Conclusions
• Precautionary and environmental principle have to be combined in order to achieve optimal cost and environmental effectiveness.
• A consistent methodology is needed to trace “pollution” loads (sources, pathways, storage and losses) from their source to the Black Sea consisting of mass balances and dynamic models combining the hydraulic, hydrological and biological processes in the catchment, the rivers and the Black Sea.
• Decision making needs consent of stakeholders even there are sound scientific analyses and reliable modelling results
"Auswirkung der Versickerung von gereinigtem Abwasser auf das Grundwasser" - Konstanz, 11.4.2000; Birgit Vogel
Danubs Team