Download Presentation - Copernicus.org

CC-WaterS - Climate Change and Impacts on Water Supply
Title
CC-WaterS - Climate Change and Impacts on Water Supply
Title
3 test sites:
1.Belgrade GW Source
2. Pek River
Catchment
3. Nisava River
CatchmentMediana site
CC-WaterS - Climate Change and Impacts on Water Supply
Title
Main characteristics of the Belgrade test area
• Test Area 18 includes 241 km2 of lowland of the Sava Valley.
• There is one groundwater body of intergranular porosity.
• It is largely recharged by the Sava River and discharged via
the wells of the Belgrade Groundwater Source (4-5 m3/s).
Proposed Natura 2000 sites
Map showing groundwater level contours
in October 2008
Nominated Natura 2000 sites
CC-WaterS - Climate Change and Impacts on Water Supply
Title
Methodology, simplifications and assumptions
• The elements of the water balance were integrated by
hydrodynamic calculations using MODFLOW 2000 software
• Main simplifications and assumptions
• River Sava -studied aquifer contact will retain const.
(conductance of the river bottom is constant)
• The boundary condition in the disregarded portion of the
area is predominantly under the influence of vertical water
balance parameters -climate parametars
• The current status of the proposed Natura 2000 sites is a
result of the groundwater regime (the impact of
irrigation/drainage canals is small or negligible).
CC-WaterS - Climate Change and Impacts on Water Supply
Title
Reference value for 1961-90
• Model calibration, validation and sensitive analisys – done for the 2005-2008
with needed opservations – data for river water fluctation, water abstraction,
ground water level fluctation, temperature, precipitation, evapotranspiration
GW recharge,
• Reference status of the GWB – GW levels at selected sites (ecological criteria) in
2008 year.
Future – estimated value
• Selection of representative periods - Long-term (8 to 10 years) average amounts
of precipitation – MINIMUM
• As a result, the 2021-29 period was deemed to reflect the representative state
for 21-50 period, and the 2093-2100 period to reflect the average state for 71100.
• GW calculations -Hydrodynamic analyses using modified boundary conditions
derived on the basis of precipitation and temperature in future periods.
CC-WaterS - Climate Change and Impacts on Water Supply
Title
•
•
Empirical functions were used for the correlation between precipitation and “potential” infiltration by month.
The rate of evaporation from grassland at ground level was computed applying a modified Penman method.
Effective infiltration was computed using the hydrodynamic model, as the difference between a given
potential infiltration rate and the computed rate of evaporation from the water table, as a function of the
depth-to-groundwater.
Based on the correlation between PET and temperature levels by month, it was assumed that the current
correlation can be used to predict future potential evapotranspiration. According to these data, the effect of
temperature on PET is more pronounced between May and October (fig.1a).
For future estimation of the ETo at critical periods, the “registered” historical value was selected. Based od
the average annual temperature and average summer temperatures in future periods, and the closest
recorded (with all data needed) values, ET0 in the prognostic calculations was adopted. Specifically, 1994 is
the representative year for the 2021-2050 period, and 2000 is the representative year for the 2071-2100
period.
Potential infiltration (mm/month)
•
Precipitation (mm/month)
Correlation between recorded temperatures and PETo-Penman (Fig 1a) and correlation between precipitation and infiltration by month
(fig 1.b)
CC-WaterS - Climate Change and Impacts on Water Supply
Title
Methodology, simplifications and assumptions ... Continue
Assessment of groundwater levels, river fluctuations, abstractions, drainage system performance and climate data, and
selection of periods for further analysis
Monthly precipitation levels --->
infiltration, temperature and
evapotranspiration
Method
Empirical approach, Penman
1960-2006
Present, 2008
Assessment of
dependency of boundary
Calibration of the H-D
conditions on met. data
model parameter
Statistical approach,
correlation
MODFLOW 2000
1982-1990
2005-2009
Calculations - H-D model - MODFLOW 2000,
by month
2021-2050
2071-2100
Sava River
Synthetic year
85-2009 data
Synthetic year
85-2009 data
User demand
Temperature
Planned groundwater
source revitalization –
most important user
Average for the period
Same as in the previous
period
Average for the period
Belgrade, 2005-2009
Empirical dependency on
precipitation
Average and for the critical
2021-2029 period
Empirical approach, 20212029
Average and for the
critical 2093-2100 period
Empirical approach,
2093-2100
Grassland, Penman, Belgrade
2005-2009
Based on average and
summer temperatures,
selected year 1994
Based on average and
summer temperatures,
selected year 2000
Precipitation
Infiltration
Potential Eto
2005-2009 rate of abstraction
from 4500 to 4000 l/s
Remarks
k/d same as today
Change from 4000 to
5100 l/s, agricultural
demand only 70 l/s in
2100
Available water resources
Criteria
Constraints
Present, 2008
Future, 2021-50
Future, 2071-2100
Present groundwater levels
and discharge from the
Zivaca Pond
Present GWL and Q
from the Zivaca Pond
Present GWL and Q
from the Zivaca Pond
Reduction in abstractions
for drinking water supply
Reduction in
abstractions for drinking
water supply
Additional water
management measures
needed
CC-WaterS - Climate Change and Impacts on Water Supply
Title
Water demand of the ecosystems
The ecosystem demand is associated with the need to maintain favorable
groundwater levels in the forest zones (Bojčinska Šuma and Crni Gaj), and to
conserve the groundwater regime which affects the extent of water losses due to
infiltration from the Živača Pond.
The extent to which these conditions may vary due to climate change is shown via
duration curves for reference parameters, water levels for the forests and the rate
of infiltration for the Živača Pond. Graphics were prepared for the year 2008,
which is representative of a sustainable state, and the average, synthetic year
which represents the 2021-50 period, and finally the 2071-2100 period.
CC-WaterS - Climate Change and Impacts on Water Supply
Title
Results
GW levels (a.s.l.)
GW levels (a.s.l.)
With regard to the analyzed aquifer (or water resource), no variation in
water availability for drinking water supply is expected in view of the
configuration of the water source and the size of the river from which the
aquifer is predominantly recharged.
However, an analysis of the potential impact of climate scenarios on the
forested areas classified as Natura 2000 sites, shows a different picture.
Based on graphically interpreted groundwater levels at these sites, a
significant impact may be expected in the Bojčinska Šuma area, which is
at a relatively large distance from the Sava River and the wells of the
Belgrade Groundwater Source.
Duration (%)
Duration (%)
Computed water level duration curves for Crni Lug and Bojnička Šuma (2008 state and two future states - 2021-2050 and
2071-2100).
CC-WaterS - Climate Change and Impacts on Water Supply
Title
Main characteristics of the artificial recharged source “Mediana” test
area -the Nisava river catchment
The size of the
Nisava river
catchment area
is 4,086 km2, of
which 1,096 km2
is in Bulgaria
(transboundary
river)
Maximum
capacity -600 l/s
CC-WaterS - Climate Change and Impacts on Water Supply
Title Sensitivity to Climate Change (observed indicators)
Droughts: Spatial distribution of drought in 1990(a) and 2000(b),
and severity expressed in terms of SPI. (Spasov et al.)
Floods: On 27 November 2007, the Nišava flooded farmland in the Village of Dolac, at the
entrance to the Sićevo Gorge (Serbia Waters, 2007).
CC-WaterS - Climate Change and Impacts on Water Supply
Methodology, simplifications and assumptions
Title
- base line period 1961-1990, validation period 1991-2006 (real climate data from 8 stations)
- Estimation of future monthly discharges for periods 2021-2050 and 2071-2100 (precipitation
and temperature given by BOKU University, corrected for higher altitude stations),
- water balance elements: WATBAL model (1961-1990), MODFLOW (“Mediana” test site), for
future evapotranspiration – Empirical equation (depending on T, P) – calibrated for 1961-1990
(Isailovic et al. 2010).
- For estimation of average monthly discharges – future period (till 2100) is used Model VNC
(developed in Institute Jaroslav Cerni) – non linear correlation model
- outputs – GIS maps, data base (monthly discharges, P, T, Q min.sust., …)
Main simplifications and assumptions
•
•
•
Mediana artificial recharged water source directly depending on the Nisava river discharges at
profile of water intake
Groundwater levels in Mediana test area are strongly dependent on water in infiltration lakes
(feeding of that part of aquifer is stopped by permeable barrier and drainage system)
Upstream multipurpose reservoir “Zavoj”, since the beginning of its operation has been used
only for the production of electric power in the HPP “Zavoj” not for water supply and irrigation
CC-WaterS - Climate Change and Impacts on Water Supply
Title
Elements for surface water balance
Average annual temperatures in the Nišava
River Basin
Humidity in the Nišava River Basin
Precipitation in the Nišava River Basin
Average runoff in the Nišava river
basin
CC-WaterS - Climate Change and Impacts on Water Supply
Title
Multi-parameter non linear correlation model VNC
The model is based on the theory of non-linear standardized correlation
The essence of the VNC model is the establishment of linear correlations between
standardized variables:
- Precipitation and temperature,independent variables
-dependent variable is the discharge at the hydrological cross-section (at intake for water
supply source “Mediana” – Nis gaug.stat.
-The model boundaries were the actual boundaries of the river basin, and the exit crosssection was the Niš hydrological station located downstream from the Mediana water intake.
CC-WaterS - Climate Change and Impacts on Water Supply
Title
Results from VNC Model
Average monthly precipitation and air temperature levels in the Nišava River
Basin
Period
AVER

Cv
Cs
MAX
MIN
1961-1990
P av.
T
49.8
8.3
30.89
7.605
0.620
0.888
1.081
-0.147
220.0
23.3
0.0
-8.5
2021-2050
P
T
47.2
10.7
35.723
8.232
0.757
0.772
2.053
-0.023
358.3
28.6
0.0
-6.2
2071-2100
P
45.5
35.446
0.779
1.377
234.9
0.0
T
11.8
8.778
0.744
0.001
28.6
-5.0
Average annual discharges of the Nišava River
Period
Aver.

Cv
Cs
MAX
MIN
1961-1990
Qo
30.7
23.873
0.844
1.735
141
2.69
2021-2050
Q
27.17
17.55
0.675
1.20
114
3.13
2071-2100
Q
25.4
19.297
0.758
1.422
122
2.69
jan.2100
jan.2099
jan.2098
2071-2100 Nišava discharges at profile Niš
y = -0,0172x + 63,733
jan.2051
jan.2050
jan.2049
jan.2048
jan.2047
jan.2046
jan.2045
jan.2044
jan.2043
jan.2042
jan.2041
jan.2040
jan.2039
jan.2038
jan.2037
jan.2036
jan.2035
jan.2034
jan.2033
jan.2032
jan.2031
jan.2030
jan.2029
jan.2028
jan.2027
jan.2026
jan.2025
jan.2024
jan.2023
jan.2022
jan.2021
120
110
100
90
80
70
60
50
40
30
20
10
0
jan.2097
jan.2096
130
120
110
100
90
80
70
60
50
40
30
20
10
0
jan.2095
jan.2094
jan.2093
jan.2092
jan.2091
jan.2090
jan.2089
jan.2088
jan.2087
jan.2086
jan.2085
jan.2084
jan.2083
jan.2082
jan.2081
jan.2080
jan.2079
jan.2078
jan.2077
jan.2076
jan.2075
jan.2074
jan.2073
jan.2072
jan.2071
CC-WaterS - Climate Change and Impacts on Water Supply
Title
2021-2050 and 2071-2100 Discharge forecasts for the Nišava River at Niš.
2021-2050 Nišava discharges at profile Niš
y = 0,0023x + 23,427
CC-WaterS - Climate Change and Impacts on Water Supply
Title
Available water for artificial recharged water source “Mediana” – at profil Nis
(water intake)
Criteria need to be fulfilled
•
According to Serbian low, minimum sustainable flow must be provided downstream
from a surface water intake, to ensure the survival and growth of downstream
biocenoses and meet the water demand of downstream users (Official Gazette RS
30/10). The minimum 95% average monthly discharge is used to derive this flow rate.

Qmin,sust.flow  max Q min,95%

For future periods 2021-2050 and 2071-2100 available discharge at Niš profile is calculated
on the proposed formula :
Qavailable = Q(time,p)_Nisava – Qmin.sus.flow_Nisava.
CC-WaterS - Climate Change and Impacts on Water Supply
Title
Results:
-Qaverag.yearl. will decrease from 30.7 m3/s to 27.1 m3/s (the end of 2050.) as to
25.4 m3/s (in period 2071-2100).
-Approximately 20% of available surface water will be lost with present water
needs and efficiency of Zavoj accumulation
-Critical periods for Mediana test area will be summer months (July-August) in
period 2021-2050 which will be extended to September and October at the end
of 2071-2100 period
- Extreme events (droughts and floods) could make significant impact on water
supply system NIVOS for Nis water supply (decreasing of karst spring discharges
make pressure to Mediana test site also as increasing turbidity after heavy rain)
CC-WaterS - Climate Change and Impacts on Water Supply
Title
Conclusions for “Mediana” test site:
•
•
•
‘’Zavoj’’ reservoir shuold provide the required amount of water for water supply,
and that the amount of water discharged from the reservoir after its hydro
energetic potential has been used – regulated flow in the Nisava, meets the
irrigation water demands in the Nisava basin and significantly affects the small
waters enrichment in the dry seasons.
Ecological criteria must be satisfied downstream from water intake
Significant impact of Climate Changes on depending biodiversity may be expected
in upstream part of Nisava river basin where are protected areas : the Sićevačka
Klisura (Sićevo Gorge) and the Jelašnička Klisura (Jelašnica Gorge) Special Nature
Reserve.
CC-WaterS - Climate Change and Impacts on Water Supply
Title
THANK YOU FOR YOUR ATTENTION