the inventory of environmental problems of river dambovita,...
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The inventory of environmental problems of river Dambovita,
other than pollution
ROBESCU VALENTINA OFELIA
University Valahia of Targoviste, Romania
e-mail: robescu@yahoo.com, telefon: 004024520601
and
BERCA MIHAI
USAMV, Bucuresti, Romania
e-mail:unibercamihai@yahoo.com, telefon: 0040212080312
and
DUMITRU ION
University Valahia of Targoviste, Romania
e-mail: robescuo@yahoo.com, telefon: 004024520601
and
ALEXANDRESCU DANIELA CRISTIANA
University Valahia of Targoviste, Romania
e-mail: danaalex@yahoo.com, telefon: 004024520601
Abstract: Upper basin of the Dambovita where we made studies, totaling an area of 30,112 hectares and includes 39
villages and 9 common administrative. Dambovita river is considered the largest tributary of Arges seen in terms of its length. It stems from the Bratila peak (2274 m) through Vad Valley in Fagaras Mountains. In this paper we have
identified several environmental problems encountered in the upper basin of the Dambovita river and realized and a graphic modeling of the river, making a projection of how the river should look like, if over 10 years would be regularized. As research methodology we used pictures from a helicopter, original photographs made by the authors of
this paper and also we've used some pictures taken from Google Earth [1] with the same portion of river.
Key words: Environmental problems, Dambovita River, River regulation, River modeling
1 Introduction After a course west-east direction, between the
mountains of Fagaras and Piatra Craiului (north) and Iezer (Papusa) to the south where in 1983 they built lake Pecineagu, Dambovita river is shifting to the southeast
forming keys Plaiul Mare before it enters the depression Dambovita Bridge. Then follows Dambovita’s High
Keys, Giurgiu bridge and other mountain valley from Rucăr. Dambovita river still has a narrow valley sector Dragoslavele and Cetateni, after crossing Piedmont
Cândeşti and Romanian Plain and will spill into the Arges river at Budeşti.
The territory studied is limited to: north limit is given by the commune CetăŃeni of Arges county, east and south by the commune Runcu and Măneşti from
Dambovita County.
2 Issue 1) The first and biggest problem of the river is the lack
of regularity. Under the laws of ecology and hydrodynamics principles, they move upstream into
downstream water creates its route through areas of least resistance to ground. Although it is known that rocks
are sediments of the meadow to the upstream, drag can be adjusted on the sidelines because of their different
compaction and secondly because of installation and speed differential that ranges support the establishment of
biological populations[2]. 2) If the flow of the river directly in line with a length
of 24 km, taking into account the degree of the
convolution, the actual length of the river in the study area is 24 x1.55 = 37.2 kilometers. A length too large and
a very broad meadow, insecure, moving, random, uncontrollable, which can yield large floods, can lead to water currents and can deploy vegetation causing serious
damage. Average width of the riverbed along the 37.2 kilometers was estimated at about 18.9 kilometers (owns
determination). This means that the total area occupied by a riverbed in changing is 37.200 m x 18.9 = 70.3080 m2=70.3ha-10%, that means 70.3/30112 = 0,0023=0,23%
from basin area studied and 30112 = basin area studied or taking into account the actual length of the river = 1.89
ha per 1 km of the virtual length. This ecologic matter is not a disaster, however, is a
very bad compared to regulated rivers in Austria and Germany where the riverbed for 1 km of regulated river
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ISSN: 1790-5125 459 ISBN: 978-960-474-164-9
is not more than 0,7-1 km (some are even below 0.7 kilometers) for similar debts.
3) The third ecologic problem is the instability of riverbed and vegetation of consolidation, requiring special measures - sets a find in Figure 4.
Other side issues related to environmental issues and shown in Figure 4 are:
- Instability of banks - caused by erosion or dislocation sometimes with serious effects [3].
- Instability due to insufficient vegetation to support maturation time required plant associations [4]. Due to limited space both in time and the area of research
concerns, other micro basins, groundwater, lakes and ponds do not fall in our study.
Calculation of the coefficient of sinuosity
To calculate the actual length of the river is necessary to
know the parameters under the riverbed restructured it must carry not only the multiannual average flow of
about 10.5m3/ha (at Tatarani after Local Environmental Agency, 2008) but also extreme flows which an risk of 99% reached about 127 m3/s (1 year in 100), risk in our
opinion may be accepted.
Fig.1 The coefficient of sinuosity
But the river regularization involves other risks, namely:
- Narrowing of the river throughout the section, and particularly the base leakage
- Increased water velocity, depending on flow and can reach speeds of 6-8 m / s - Erosion if not taken appropriate measures to strengthen
the banks. The evaluation of sections to be calculated, it must be known and downhill slopes of river. Our
calculations performed on data provided by satellite shows that the first half downhill slope is 0.86 ‰ = 8.6%, steeper slope leading to a high speed water, especially at
high flow rates (section Malu cu Flori – Tatarani). In the second segment studied slope is 0.395 ‰ =
3.95%. Full segment Malu cu Flori - Tatarani, the level difference is 151 m, ie a slope of 6.3% or 0.639 ‰.
And now to calculate:
We have known the following: Bm = the riverbed base = 10 m; Qmax = maximum possible flow = 127 m3/s the
formula Q = S x Vm out values "S", ie the section values,
if we know the speed, the measurements being made in the area. Current speeds are different between surface
and deep current. According to literature, we can imagine a speed of 2 to 2.2 m/s for this difference in level. Take average of 2.1 m/s at the highest flow rates.
In these circumstances from the above formula we have: S = Q/VM=127/2.1= 60.5 m2, for insurance of 99%
(1 year in 100). Average flow of the river is 10.5 m3 /s in the S = Q/ VM=10.5/2.1=5m2. Starting from the scientific
information that the debts of over 100 m3/s on 100 m2 section below, the speed at slopes exceeding 0.2% can be increased to 3.5 m3/s, we can size the section "S" as
follows: S = Q/VM = 127/3.5= 36.2 m2
Flow regularized on
September 21, 2005 If Bs = 10 m then H =36.2/10= 3.62 Given that riverbed regulation is necessary to made
trapeze, and accepting the higher base of about 14 m, then BS = 10 x 14/2= 12 m, including any dams. In
this case the height of construction is H =36.2/14=2.58 m.
Compared to the average annual flow of the river
which would require a height of 5/12= 0.42 m. Extreme flash floods require construction of about
6.14 times the riverbed developed.
Fig.2 The riverbed section of Dambovita River for maximum
flow on the route Malu cu Flori - Tatarani.
Such a construction is not necessary if they accept
greater risks or certain areas of calm water that can be built in several large bends of the river (see Figure 6).
By accepting such a settlement and a reduction of Cs from 1.55 → 1.05, than the river area can handle only 24,000 x 12 x 1.05 = 302,400 m2 = 30.24 ha. It would
save and bring in the natural or agricultural circle 70.3 to 30.2 = 40.1 ha, ie 57% of an area unusable.
Reducing Cs can be done by redrawing the riverbed in section above. Studying models of how to do this in known countries of the EU (Germany and Austria) first
attach Figures 3 and 4.
Cs = coefficient of sinuosity
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ISSN: 1790-5125 460 ISBN: 978-960-474-164-9
Fig.3 Satellite images regarding Earl river planning.
Earl River, a tributary of Isar, is, in turn a tributary of the
Danube. Calculations show that on this segment Cs = 1.02.
Fig.4 Small river, regularized, a tributary of the Danube in
eastern Austria, with a Cs ≈ 1.04.Riverbanks are biologically
enhanced with shrubs and trees formed predominantly of Salix
and Populus. The settlement was built and a mini power station (at the bottom of the figure). Original photo.
Details of proposals for regularization of rivers covered by the literature and will not be included in this case study. In a series of photos taken from a helicopter or
captured from satellite, based on calculations made above, we outlined with red the possible paths of a
riverbed regularized, upgraded (Figures 5,6,7,8,9). Following these adjustments would achieve the following parameters of river.
→ Actual length = 24 x 1.05 = 25.2 kilometers → The area covered by riverbed 'A' = 30.24 ha
→ The area removed from the degradation = 40.2 ha → Improving the safety of habitats and housing = 99%.
For example, in Figure 5 and 9, in addition to plotting hypothetical riverbed, was performed a modeling of how the river could look like and ecosystems adjacent too, at
most 10 years of making the investment. Modeling shows that the Dambovita river can become a true organic oasis
anthropogenic controllable in excellent natural ecosystems, preserved long term[5]. We could speak of a true sustainability of the area studied.
Fig. 5 Picture of Dambovita river, Tatarani area Satellite
photography, green white and white is riverbed, unregularized
Cs = 1.5 of this area (photo from 1410 m, red lines drawn by
us is proposed redrawing of the riverbed.
Fig.6 Reconstructed model, by modeling.
Fig.7 A segment of the Dambovita river at Tatarani (satellite photo) of about 800 m, 350 m altitude (photo of the 880 m
high).
Red lines represent our proposals for redrawing the riverbed and reducing degradation. Warning: square
bordered in black could - if is necessary - to become a square to calm the waters, in which should be reclaimed
from the sea at least the same height as the bed regularized.
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ISSN: 1790-5125 461 ISBN: 978-960-474-164-9
Fig.8 Picture taken from a helicopter to a broad segment of the
Dambovita river (original)
And proposal for regularization with large effects on reducing the degradation of natural and agricultural
ecosystems.
Fig. 9 Reconstructed model of river, by modeling.
Fig.10 Brief model of a segment regulation of Dambovita river
affected by significant degradation.
Fig.11 River in the stretch of river studied, proposed for
regularized, the elimination of multiple threads of riverbed
and recovery for natural and agricultural ecosystems of the
areas affected.
Fig.112 Segment of Dambovita river proposed for regulation in
order to avoid degradation and soil losses thanks to natural
riverbed oversized.
Fig.13 With this restructuring of riverbed DâmboviŃa is
gaining a important area of the affected area and plays other
types of ecosystems.
Fig.142 Possibilities for restructuring of a part of the
DâmboviŃa river from area studied (photo helicopter, original).
Fig. 15 The idea of upgrading a segment of the DâmboviŃa
river in the area studied. More threads are deleted and recovered ground for agriculture and natural ecosystems (photo
helicopter).
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ISSN: 1790-5125 462 ISBN: 978-960-474-164-9
Fig.163 Original image, from the helicopter, of Dambovita
River, and redevelopment proposed, with significant recovery.
Unusable areas, the riverbed due to frequent changes.
Fig. 174 Proposal to regularization DâmboviŃa river on a picture made from the helicopter and restoration to the
agricultural and natural ecosystems the areas outside of the
red lines.
Fig.18 Photo from the helicopter (the original) on a segment of
the Dambovita River study and proposal for regularization.
3 Conclusions The study revealed three major environmental problems along the DâmboviŃa River in its upper basin, namely:
a) Lack of riverbed regularization that leads to: - More yarn flow - Drive enormous deposits with irregular and unstable
deposits - Changing the riverbed
- Degradation of the riverbanks, riverbed erosion and permanent expansion
- Loss of biodiversity - Instability surrounding ecosystems b) The excessive length of the river, a winding factor too
high, and a doubling of the area needed to conduct water downstream (removing an important useful area of
stream ecosystems and transformation in surface unnecessary).
c) Riverbed instability, generated by its lack of regularity and unpredictability of future developments: further erosion and land slides.
2) Our studies have demonstrated that river regulation can be made by a section S = 36.2 m2 and a maximum
height of excavation + embankment 2.58 m. 3) Stabilization of organic banks will be biological, using
shrubs and trees suited to the zone under the proposed scheme. 4) Reclamation of land affected by the lack of
regularization of riverbed will exceed 40% (50%) of total area. It will be returned to adjacent ecosystems, to be
integrated into it. Biodiversity will increase by 60% and will stabilized due to the presence of moisture in the area. 5) Regularization of the river and proposed
environmental reconstruction could cost around 25 million euro, recovered in about 15 years.
6) The effects of such an investment would lead to creation of optimal relations between the river and plant associations, which would consolidate a highly
sustainable ecosystem in the area, with a high degree of landscape and tourist attractions.
References:
[1]Berca Mihai, Probleme de ecologia solului, Ed. Ceres, 2008.
[2]Berca Mihai, Gestiunea Mediului şi a resurselor naturale,
Editura Ceres, 2008
[3]Berca Mihai, Robescu Valentina Ofelia, Researches on the
Management of Economy Dematerialization in the
Agriculture of Dambovita County, Romania, Proceedings of the 7th WSEAS International Conference on
Environment, Ecosystems and Development (EED
'09)Tenerife, Spain December 14-16, 2009, pg. 162-168.
[4] Berca Mihai, Robescu Valentina Ofelia, Buzatu Cristiana
The Natural Model of Biomass Growth and Biomass
Quality in Agroecosystems of Meadows from Northen Part
of Dambovita County, Romania, Proceedings of the 7th
WSEAS International Conference on Environment,
Ecosystems and Development (EED '09)Tenerife, Spain,
December 14-16, 2009 , pg. 186-190.
[5] Robescu Valentina Ofelia, Modele privind managementul
reconstructie de mediu in bazinul superior al raului
Dambovita, Editura Ceres, 2009, ISBN 978-973-40-0820-9.
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ISSN: 1790-5125 463 ISBN: 978-960-474-164-9
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