ANALYSIS OF COMBINED IMPACT OF GROUNDWATER DROUGHT AND WATER SCARCITY INDEX FOR INTENSIVELY OVER DRAFTED AQUIFERS

1. Presented by, Guided by,
Megha S Thampi Dr. K S Sumam
TCR18CEWR12

2. • Introduction
• Methodology
• Case study
• Results and Discussion
• Conclusions
• References
2

3.  Ground water drought
-reduction in ground water level, ground water
discharge, and ground water recharge.
 Water scarcity
-over exploitation of water resources when demand
exceeds availability.
 Ground water drought indexes
SPI,GRI,SGI,GWI
 Water scarcity
DR
 DAI
3

4. Conceptual MODFLOW Model
Ground water modelling software
Porous medium
4

5. Artificial Neural Network Model
 Surrogate model
 Replace time-intensive complex numerical models.

6.  Conducted by Hamid Sanginabadi, Bahram
Saghafian and Majid Delvar.
 Qazvin plain
 110 boreholes
 Spatial monthly
average of ground
water level.
6

7. 7
Variation of ground water abstraction in volume.

8. 8
Time series of ground water level and precipitation since 1966

9. CONCEPTUAL MODFLOW MODEL
 9028 uniform square mesh
 Each of 1,000 x 1,000 m2
 122 columns
 74 rows
9
MODFLOW domain and
boundary conditions in
qazvin plain

10.  Rivers defined as lines.
 Inputs
◦ River surface water
head
◦ Elevation of the river
bed
◦ Hydraulic conductivity
 Water head – Stage
discharge curves.
 Hydraulic conductance
calibrated – Trial and
error method.
 Unsteady condition
 Simulation time step - 1
month
 Simulation time unit – 1
day.
 Input parameters – daily
average per month.
10

11.  Calibration period
◦ October 2014 – September
2015
 Hydraulic conductivity
◦ 0.1-32 m/day.
 Transmissivity
◦ 200-12,200 m2/day
 Specific yield
◦ 0.02-0.13
 Percentage of precipitation
◦ 14%
 Well water harvested
◦ 28%
 Unregulated abstraction
◦ 16%
 Hydraulic conductance
◦ 200- 6,000 m2/day.
 Validation period
◦ October 2012 – September
2013
11

12.  Calibrated MODFLOW model – run for different
conditions.
 Inputs – Precipitation, Evapo-transpiration, stream
flow, abstraction, and initial ground water level.
 Model was run 300 times.
 Simulate ground water level at each bore hole.
 Spatial average
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13. Artificial Neural Network Model
 ANN model was trained and tested
 Similar input
 Corresponding average ground water level- output
 Abstraction – zero
 Stream flow naturalization performed via regression
 Two naturalized and de-trending approaches were
compared and graph is plotted.
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14. Drought Indexes
 Hydrological drought monitoring - Standardized
Hydrological Drought Index (SHDI).
 Ground water drought – Standardized ground water
index (SGI).
14

15. Water Scarcity Indexes
15
Graphical representation of ground water drought and
water scarcity

16.  Water Exploration Index (WEI)
 Aquifer water scarcity index
 Actual ground water abstraction
◦ Naturalized ground water level – observed ground water level.
16
nabstractioactual
nabstractioallowablenabstractioactual 
.resourcerenewabletermlongTotal
nabstractiowaterfreshannualTotal

17.  Allowable ground water abstraction
◦ Naturalized ground water level – safe ground water level.
 Drought threshold level- To distinguish between the
effect of natural factors and human factors.
◦ Zero SGI
1
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18. Coupled Ground water Drought water Scarcity
Index
 Drought water scarcity index (DWS).
 D*Sk
18
)S(logK)D(logDWS nn 21 

19. Naturalized Ground water level
19
Observed and simulated average ground water level of
the study period

20. 20
Observed, naturalized and slope - detrended ground
water level
RESULTS AND ANALYSIS (Cont…)

21. 21
Water budget ( in hm3/day) in Qazvin aquifer for calibration period
(2013-2014) and a wet period (1996-1997)

22. Calculation of Naturalized and Detrended
levels
22
Scatter plot of detrended and naturalized
ground water levels.

23. Ground water Drought Analysis
23
SGI time series

24. 24
SGI and SPIq

25. 25
SGI and SHDIq

26. 26
Strongest cross – correlation between SGI and SHDI / SPI

27. 27
SGI ,SHDI48 (with out lag) and SPI48 ( with a lag period of 3 months)
Time series

28. 28
Deviations in the naturalized and observed ground
water level

29. Number, duration and value of aquifer deviation
29

30. 30
Drought, Water Scarcity and Drought water scarcity
classification

31. 31
Ground water drought

32. 32
Water scarcity

33. Ground water drought water scarcity
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34. 34
ANN DR forecast model.

35. Changes in the DWS indexes corresponding to different volumes
of abstraction over the next 5 years.
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36.  Using a simple detrending technique leads to
significant error in ground water drought analysis.
 Strongest relationship between the SGI and SPI
occurred for SPI48 with a lag period of 3 months.
 SGI is strongly correlated with the SHDI than with the
SPI.
 The negative impact of human causes on the
hydrological conditions is larger than that of natural
causes.
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37.  A new index, named DWS, was introduced to monitor
the compound effect of groundwater drought and water
scarcity.
 The DWS index could be used to determine the safe
yield of the aquifer.
 The state of groundwater corresponding to different
volumes of abstraction was determined for the next 5
years.
37

38.  Hamid Sanginabadi; Bahram Saghafian; and Majid Delavar, Ph.D. (2019)
“Coupled Groundwater Drought and Water Scarcity Index for Intensively
Overdrafted Aquifers”.Journal of Hydrologic Engineering/ Volume 24
issue 4.
 Eva W.Mooers, P.Eng.; Rob C. Jamieson, P.Eng; Jenny L. Hayward, P.Eng.;
John Drage; and Craig B Lake, P.Eng. (2018) “Low-Impact Development
Effect on Aquifer Recharge Using CoupledSurface and Groundwater
Models.”Journal of Hydrologic Engineering/ Volume 23 issue 9.
 P. Marcos-Garcia , A. Lopez-Nicolas, M. Pulido-Velazquez.(2017)
“Combined use of relative drought indices to analyze climate change
impact on meteorological and hydrological droughts in a Mediterranean
basin.”Journal of Hydrologic Engineering/ Volume 554Pages 292-305.
 Mohamed TaherKahil, Ariel Dinar, Jose Albiac .(2015)“Modeling water
scarcity and droughts for policy adaptation to climate change in arid and
semiarid regions.”Journal of Hydrologic Engineering/ Volume 552 Pages
95-109.
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