1. Assessment and planning of the water resources under various scenarios in the Ganges and Indus basin: Glaciers contribution and WEAP modelling Devaraj de CONDAPPA Marisa ESCOBAR Luna BHARATI Priyantha JAYAKODY Stockholm Environment InstituteInternational Water Management Institute CPWF Basin Focal Project for the IG Basin 2 - 3 December 2009, New Delhi

2.  Mac Kirby [Eastham et al. (2008)] gave an overview of hydrological water uses in the IG Basin.  Objective here: develop an application of the Water Evaluation And Planning (WEAP) in the Indus and Ganges basin so as to: assess the water resources, in particular contribution from glaciers, model its utilisation / planning, and provide insight into some possible future scenarios.  Outline of the presentation: 1.Brief introduction to WEAP. 2.Input data gathered. 3.Setting WEAP in the Indus and Ganges. 4.Analysis of simulations: current situation, scenarios. 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios Objective

3. Water Evaluation and Planning (WEAP)  Developed by the Stockholm Environment Institute (SEI).  Models simultaneously: hydrology: the water resources, planning: uses of these resources.  Hydrology: model rainfall / runoff: based on  landuse;  soil parameters. 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

4. Water Evaluation and Planning (WEAP)  Hydrology: glaciers module:  models variation in glaciers area, streamflows,  based on degree-day approach, i.e., streamflow calculated with the potential  sub-division of a catchment: degree day factor for ice or snow (mm/°C/day) rain / snow temperature threshold (°C) 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

5. Water Evaluation and Planning (WEAP)  Planning: basically solved by a linear program (LP), which attempts to optimize coverage of demand sites, and instream flow requirements, subject to demand priorities, supply preferences, mass balance and other constraints. 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

6. Input data gathered  Climate: the TS 2.1 dataset from the Climate Research Unit (CRU).  Observed streamflows: International databases; IWMI: Upper Kosi (Nepalese part) and Upper Ganges; some time series in the Indus extracted from the spreadsheet of Eastham et al. (2008); average annual trends from Jain et al. (2007) in the Ganges. 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

7. Input data gathered  Observed streamflows: 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

8. Input data gathered  Glaciers coverage: 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

9. Input data gathered  Landuse: from IGB Tool Kit (Global Land Cover 2000) 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

10. Input data gathered  Water uses: Irrigation, Domestic and Industries in India: from Amarasinghe et al. (2007), in Pakistan: from Habib (2004).  Infrastructures: canals: internet + Habib (2004) for the Indus Basin Irrigation System, large reservoirs: Jain et al. (2007) + internet, Google Earth for locations. Madhya canal Bisalpur reservoir 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

11. Modelling units: sub-basins  Generation of sub-basins with respect to: available observed time series of streamflows, large reservoirs or barrages, major river outlets (where some average annual flows were available). 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

12. Modelling units: … subdivided by elevations bands  First band 0 – 3,000 m,  Then every 1,000 m. 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

13. WEAP-Indus and WEAP-Ganges 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios WEAP-Indus down to Kotri WEAP-Ganges down to Farakka Hydrological objects Water demands

14. WEAP-Ganges 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

15. Reliability of WEAP-Indus & WEAP-Ganges 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

16. Reliability of WEAP-Indus & WEAP-Ganges 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios Calibration Validation Calibration

17. Reliability of WEAP-Indus & WEAP-Ganges  What can these WEAP applications simulate? 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

18. Analysis current situation: rainfall  Current situation = period of reference: last 20 years of CRU data  1982 to 2002. 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios CRU rainfall

19. Analysis current situation: water uses 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios In the Ganges Adapted from Amarasinghe et al. (2007) For year 2000 In the Indus: Adapted from Amarasinghe et al. (2007) and Habib (2004) lumped demand for the Indus Basin Irrigation System For year 2000

20. Analysis current situation: impacts of canals 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios In the Indus Average annual streamflows, simulated for period 1982 - 2002 In the Ganges

21. Analysis current situation: impacts of canals 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios In the Ganges, Haridwar Upper Ganga canal In the Ganges, Narora Madhya & Lower Ganga canals In the Ganges, Tajewala Western & Eastern Yamuna canals Average monthly streamflows, simulated for period 1982 - 2002

22. Analysis current situation: contribution from glaciers 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios Haridwar Before canal Haridwar After canal Average streamflows simulated for period 1982 - 2002 Farakka

23. Analysis current situation: contribution from glaciers 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios Danyour Bridge Tarbela dam Sukkur Indus heavily depend on contribution from glaciers Tarbela dam Sukkur

24. Scenario analysis: increase in temperature  According to the IPCC: temperature +3.8 °C at the end of the century in the Tibetan region.  Same order by ICIMOD.   considered 3 scenarios for 20 years: +1°C after 20-years, i.e., a rate of +0.05°C/year, +2°C after 20-years, i.e., a rate of +0.10°C/year, +3°C after 20-years, i.e., a rate of +0.15°C/year.  Compared to the reference scenario = period 1982 to 2002. 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

25. Scenario analysis: increase in temperature 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios HaridwarDevghats Farakka Risks of floods

26. Scenario analysis: increase in temperature 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios Danyour Bridge Tarbela dam Sukkur Risks of floods

27. Scenario analysis: increase in temperature  Additional annual flow:  Additional flow mainly during the high flow season  how to use it?  Tricky as high discharge.  Maybe extra flows in April, May & June + September & October? 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios Ganges Indus

28. Scenario analysis: reduction in initial glaciers  What could be consequences of a drastic reduction in glaciers coverage?   considered 4 scenarios for 20 years: initial decrease in glaciers coverage by 25, 50, 75 and 100%. 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

29. Scenario analysis: reduction in initial glaciers 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

30. Analysis scenario: reduction in initial glaciers 0. Outline2. Input data4. Current situation 1. WEAP3. Setting WEAP Scenarios

31. Devaraj de CONDAPPA devaraj.de.condappa@googlemail.com