AN INTEGRATED FRAMEWORK FOR EFFECTIVE ADAPTATION TO CLIMATE CHANGE IMPACTS ON WATER RESOURCES

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1 AN INTEGRATED FRAMEWORK FOR EFFECTIVE ADAPTATION TO CLIMATE CHANGE IMPACTS ON WATER RESOURCES A. K. Gosain, Professor & Head Civil Engineering Department Indian Institute of Technology Delhi:

2 Water resource development 2 Shall always remain one of the preferred options to cater to Inherent Spatial variability and Temporal variability of this resource Climate change impacts Monday, July 23, 2012

3 3 Implications of Development -(or Interventions) Water resource is finite (within natural variability) Any development big or small involves in moving the water around (more often upstream) Thus every intervention has an associated impact Monday, July 23, 2012

4 What are the issues & concerns? 4 No mechanism in place to arrive at tradeoffs between the competing demands No mechanism to decide the extent of watershed management Promoting rainwater harvesting without setting the limits Ignoring the environmental demand Ignoring the hydrological health (interaction between surface and ground water) Ignoring the water quality issues Monday, July 23, 2012

5 Sustainability This brings us to the question of sustainability Which is about maintaining the hydrological and environmental health of the drainage system IWRM philosophy has been the scientific option available but seldom used Watershed being the natural system where water balance can be resolved and thereby impacts of the manmade interferences quantified

6 India s National Communications to UNFCCC Coordinated by MoEF The first communication was made in 2004 It was a multidisciplinary effort Work on water Resources was entrusted to IIT Delhi Second National Communication has just started and IIT Delhi is again leading the Water Resources work

7 NATCOM MoEF Climate Change and its Impact on Water Resources of India Tools used Modelling: SWAT (Soil and Water Assessment Tool) GIS framework: acts as a pre-processor for the distributed modelling and for visualization of the outputs/results in terms of V & A Data used Digital Elevation Model: SRTM 90 m Land use: Global data, 1:2M USGS Soil: Global data, 1:5M FAO Drainage: 1:250,000 Weather: IPCC SRES A1B, A2, B2, Hadley Centre U.K. at a resolution of 0.44 X 0.44 latitude by longitude grid points obtained from IITM, Pune Impacts Studied Impact on annual water availability Impact on seasonal water availability Impact on inter annual water availability Regional Variability of Water availability Extreme events Floods and Droughts

8 SWAT (Soil and Water Assessment Tool) - Model Features Physically based Distributed model Continuous time model (long term yield model) Uses readily available data Used for long term impact studies

9 Ganga Basin Hydrological Modelling Base layers

10 Ganga Basin Hydrological Modelling SWAT Outputs

11 Stream Discharge (cumecs) Jan/69 May/70 Sep/71 Jan/73 May/74 Sep/75 Chisapani - Nepal 2500 Jan/77 May/78 BeniGhat/Chisapani Sep/79 Jan/81 May/82 Sep/83 Month-Year Jan/85 May/86 Sep/87 Jan/ FLOW_OUTcms May/90 Sep/91 Jan/93 Stream Discharge (cumecs) Jan/69 May/70 Sep/71 Jan/73 May/74 Sep/75 DevGhat - Nepal Devghat Observed Vs. Simulated Time Series Plots Jan/77 May/78 Sep/79 Jan/81 May/82 Sep/83 Month-Year Jan/85 May/86 Sep/ FLOW_OUTcms Jan/89 May/90 Sep/91 Jan/93 Stream Discharge (cumecs) Jan/76 Aug/76 Mar/77 Oct/77 May/78 Dec/78 Jul/79 Feb/80 Sep/80 Apr/81 Nov/81 Jun/82 Jan/83 Aug/83 Mar/84 Oct/84 May/85 Dec/85 Jul/86 Turkeghat - Nepal Turkeghat Month-Year 121 FLOW_OUTcms

12 Vulnerability Assessment Procedure Palmer Drought Severity Index (PDSI) widely used index incorporates information on rainfall, land-use, and soil properties in a lumped manner PDSI value below 0.0 indicates the beginning of drought situation A value below -3.0 as sever drought condition Soil Moisture Index to monitor drought severity using SWAT output to incorporate the spatial variability

13 Change in water balance components Change in value (%) Change from Baseline to Mid Century (-ve shows increase in mid century) Baitarni Brahmani Brahmaputra Cauvery Ganga Godavari Indus Krishna Luni Mahanadi Mahi Meghna Narmada Pennar Sabarmati Major River Basins Precipitation Water Yield Actual Evapotranspiration IPCC SRES A1B - Q14 QUMP Ensemble Subernrekha Tapi Change in value (%) Change from Baseline to End Century (-ve shows increase in end century) 40.0 Baitarni Brahmani Brahmaputra Cauvery Ganga Godavari Indus Krishna Luni Mahanadi Mahi Meghna Narmada Pennar Sabarmati Major River Basins Precipitation Water Yield Actual Evapotranspiration IPCC SRES A1B - Q14 QUMP Ensemble Subernrekha Tapi

14 Change in precipitation towards 2030s and 2080s

15 Change in Water Yield towards 2030s and 2080s

16 Change in Evapo-transpiration towards 2030s and 2080s

17 Change in Sediment Yield towards 2030s and 2080s

18 Change in monsoon drought weeks towards 2030s & 2080s

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21 Possible adaptation options 21 Enhanced efficiencies Surface water Interventions different scales Big projects Reservoir or runoff the river scheme Medium & Minor schemes Watershed level check dams Ground water exploitation Shallow wells Deep tubewells Monday, July 23, 2012

22 Interventions have implications 22 Every intervention big or small has associated impact Integrated Watershed philosophy was the scientific option suggested Watershed being the natural system where water balance can be resolved and thereby impacts of interventions quantified Integrated implies consideration of all possible usage and interest of all stake holders Monday, July 23, 2012

23 The major concern 23 Evaluate the implications of climate change by incorporating the baseline Adaptation shall require enhanced level of interventions through line departments A common framework is required to provide an integrated information base Procedures for scenario generation and evaluation Monday, July 23, 2012

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27 Conclusions 27 Integrated water resource development and management framework is required to be adopted Creation of sharable information is essential for sustainable use of water resources This shall be a good way forward for selecting meaningful adaptation options to development and climate change impacts Monday, July 23, 2012

28 THANK YOU