VOL. 9, NO. 11, NOVEMBER 2014 ISSN 1819-6608 ARPN Journal of Engineering and Applied Sciences © 2006-2014 Asian Research Publishing Network (ARPN). All rights reserved. www.arpnjournals.com 2183 ASSESSMENT OF WATER RESOURCES UNDER CLIMATE CHANGE: DAMODAR RIVER BASIN, INDIA Mangolika Chatterjee, Debasri Roy, Subhasish Das and Asis Mazumdar School of Water Resources Engineering, Jadavpur University, Kolkata, West Bengal, India E-Mail: debasri_roy1@yahoo.co.in ABSTRACT This study evaluates the impact of climate change on water resources of the Damodar river basin in eastern India. Future climate scenario has been framed based on climate projections of regional climate model PRECIS (Providing Regional Climates for Impacts Studies) of the Hadley Centre for A1B scenario [Special Report on Emissions Scenarios (SRES) prepared under the Intergovernmental Panel on Climate Change coordination (IPCC)]. A continuous daily hydrologic model HEC-HMS (Hydrologic Engineering Centre-Hydrologic Modelling System) calibrated for the basin was used to simulate the daily hydrological condition for baseline period 1985-1990 and future period 2014-2025. The impact assessment has been carried out by comparing baseline and future precipitation, potential evapotranspiration (PET) and flow regimes and also performance of the Damodar Valley Corporation (DVC) system of reservoirs. Decrease of projected rainfall was noticed for months of July and August and increase of projected rainfall was observed for months of January and June for all sub-basins. The projected PET values for all sub-basins were found to be higher than corresponding baseline values during February to June and lower than corresponding baseline values for November to January. Increase of projected flow over the corresponding baseline flow was noted for months of January and June and decrease in projected flow was noted for the months of July and August for all sub-basins. Reliability of meeting municipal and industrial demands was found to be 100% during the months of June to December in projected years and in baseline years for all the reservoirs. Keywords: climate change impact, damodar river, HEC-HMS, reliability, PRECIS model. INTRODUCTION Climate change is expected to create many challenges (including water availability) worldwide and projecting the impacts of climate change at regional scale allows communities to be proactive in planning for the future. South Asia in general and India in particular, are particularly vulnerable to climate change and its adverse socio-economic effects. Therefore, there is a need to evaluate the impact of climate change on water resources in India at regional and local level. A lot of work on evaluation of impact of climate change in water sector has been done worldwide. It was predicted that the changes in global river flow under the IPCC SRES A1B and A2 scenarios found from HadGEM1-TRIP model [1]. Global climate models (GCM), CGCM2, CSIROMk2 and HadCM3 were applied [2] to estimate future water availability of Okanagan basin in England. Climatologic data bases (SICLIM and CLICOM) built by the Servicio Meteorológico Nacional (SMN) of Mexico [3] was fed to a hydrologic model to predict the annual volume of superficial available water in Mexico. The climate change impact was studied on the performance of Hirakund reservoir on the Mahanadi River in Orissa, India [4]. It was seen that hydropower generation [5, 6] and reliability with respect to hydropower and irrigation to be decreased in future in most scenarios. The impacts of possible future climate change scenarios were evaluated on the hydrology of the catchment area of the Tungabhadra River, upstream of the Tungabhadra dam [7]. The Hydrologic Engineering Center’s Hydrologic Modeling System (HEC-HMS) version 3.4 was used for the hydrological modeling of the study area. Linear regression-based Statistical Down Scaling Model (SDSM) version 4.2 was used to downscale the daily maximum and minimum temperatures and daily precipitation in the four sub-basins of the study area. The large-scale climate variables for the A2 and B2 scenarios obtained from the Hadley Centre Coupled Model version 3 were used. A regional climate model data was used from the Ensemble-Based Predictions of Climate Changes and their Impacts (ENSEMBLES) project to drive the Precipitation - Runoff - Evapotranspiration - Hydrotope (PREVAH) hydrological model in order to assess the impact of climate change on the hydrology in the Rhine basin in Europe [8]. An analysis was made on the potential hydro- climatic change in the Peace River basin in the province of British Columbia, Canada, based on two structurally different approaches: (i) statistically downscaled global climate models (GCMs) using the bias-corrected spatial disaggregation (BCSD) and (ii) dynamically downscaled GCM with the Canadian Regional Climate Model (CRCM) [9]. Additionally, simulated hydrologic changes from the GCM-BCSD-driven Variable Infiltration Capacity (VIC) model were compared to the CRCM integrated Canadian Land Surface Scheme (CLASS) output. Overall, the GCM-BCSD-VIC approach was reported to be the preferred approach for projecting basin- scale future hydrologic changes, provided that it explicitly accounted for the biases and included plausible snow and runoff parameterizations. This paper addresses a study on the assessment of impact of climate change on water resources of the