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INTERNATIONAL ASSOCIATION OF HYDROGEOLOGISTS Australian National Chapter
NSW Branch
2009 Seminar Series
This presentation is made available by IAH NSW in the interests of promoting discussion, critique and exchange of knowledge.
The content, products, methods, equipment, findings or recommendations of these presentations are not endorsed by IAH NSW or by UNSW who has offered to host the presentations on their website www.connectedwaters.unsw.edu.au
Claire Glendenning Claire Glendenning Supervisor: Dr Willem Supervisor: Dr Willem VervoortVervoort
Evaluating the impacts of Evaluating the impacts of RRainWWater HHarvesting (arvesting (RWHRWH) ) in the in the ArvariArvari River, IndiaRiver, India
Faculty of Agriculture, Food and Natural Resources The University of Sydney
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Groundwater in India• World’s largest user
• ~ 80% rural domestic use ~ 45% for irrigation
• <1 million tubewells (1960)to 20 million (2000)
• Common resource = Decline
• Management option: RRainwwater HHarvesting (RWHRWH)?
• collect/store RUNOFF for DIRECT USE or RECHARGE
What is RRainwwater HHarvesting?
Catchment
Storage
September 06 December 06
3
• > 1000 years in India
• Monsoon: 100 hr rainfall (80 days)/yrRWHRWH=more time for recharge
• past neglect, now large reinvestment
• Impacts?
RWHRWH in India
Quantified field studies of RWHRWH• Recharge = 3 – 8 % P: WTF
(Badiger et al. 2002)
• Local impact on groundwater levels: 1 structure (Neumann et al. 2004, 2005)
• Limiting capacity to induce recharge WTF / water balance in 812 ha (Sharda et al. 2006)
• Hydrological catchment impacts not known(Calder et al. 2006, Kumar et al. 2006)
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Case study of Case study of RWH RWH impacts in the impacts in the
Arvari River CatchmentArvari River Catchment
How to evaluate RWHRWH impacts?
1. Field-scale impacts of RWH
2. Catchment-scale impacts of RWH
a. Build a conceptual water balance model
b. Run scenarios to investigate RWH impacts
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Case Study Location
458km2 (45,800 ha)
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7
8
28 Anicuts28 Anicuts
84 84 BandhsBandhs
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127 127 JohadsJohads
88 Medbandhi88 Medbandhi
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Monitoring Monitoring NetworkNetwork
Daily measurements in monsoon 2007 and 2008
Monitoring Monitoring NetworkNetwork
29 dug wellsdug wells which tap unconfined/shallow
aquifer
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Monitoring Monitoring NetworkNetwork
SankaraSankara
BerujiBeruji
Monitoring Monitoring NetworkNetwork
12
Monitoring Monitoring NetworkNetwork
Monitoring Monitoring NetworkNetwork
Rain Gauges
13
499 mm 494 mm
361 mm
751 mm
449 mm
897 mm
Variability of Rainfall (P)
Potential Recharge (Rep) estimates
.ep s tR A h ET O= − ∆ − −
bep avR ah=
non-rainy days
rainy days(Sharda et al. 2006)
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Rep estimates (m3/day)
+270
+270
201
260
2008
240
273
138
169
2007
Days Storage
23
19
27
55
2008
15
12
20
45
2007
Rep mm/day % P -> Rep
6
6
8
14
2007
8Lalpura Johad
8Jhiri Johad
10Beruji Bandh
22Sankara Bandh
2008RWH
Structure
Cumulative sum Rep and Cumulative sum Rainfall relationship
= RWH limited capacity to induce more recharge
LalpuraR2=0.81
BerujiR2=0.88
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Dep
th (
m)
Well Response
Bhaonta: well heights asl (m)
Bhaonta: relative well heights
Water Table Fluctuation MethodRecharge Estimation Re . hSy
t∆
=∆
2007 2008
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Comparison of recharge estimates
River flow
Recharge from Anicuts on River
42Nitata
25Kaled
44Hamirpur
Average Re mm/day
Anicut
Jul-2
007
Oct
-200
7
Jan-
2007
Apr-
2008
Jul-2
008
Oct
-200
8
Date
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Field-Scale Characteristics• High inter/intra-annual P variability
• RWH - 12-55 mm/day ~ 170-260 storage days- Dependent on P, but limiting capacity- Difference btw Johad / Bandh- ~ 7% P -> Rep
• Wells and Groundwater- No baseflow, high lateral flow - Annual fluctuation
AcknowledgementsAcknowledgements
•• Faculty of Agriculture, Faculty of Agriculture, UniUni of Sydneyof Sydney
•• TBS; TBS; KhanyialaljiKhanyialalji, , GopaljiGopalji
•• MurariMurari Lal Lal GujjarGujjar
•• ArvariArvari River Community River Community
•• Willem Willem VervoortVervoort