PERFORMANCE EVALUATION OF SALIA IRRIGATION PROJECT IN CHANGING CLIMATE

Abstract

Under climate change conditions, many water systems are projected to be less reliable and more vulnerable in meeting users' demands, exacerbating existing competition for water resources. At the global scale, water demand will grow in the next decades due to population growth, and substantial changes in irrigation water demand due to impact of climate change. National Water Mission was set up by Govt. of India recommended to study impact of climate change on water resources. The present research work aims at evaluating performance of reservoir by implementing hydrological model with climate change implication to optimize the efficiency of existing irrigation systems, expand irrigation, where feasible, with a special effort to increase storage capacity. In the current study, performance of Salia reservoir in Odisha is analyzed under climate change conditions. The thesis is focused on the following heuristics: (I) trend analysis for identification of temporal changes in hydrological parameters such as precipitation and inflows time series due to potential impacts of climate change, (ii) quantification of inflows to reservoir using ARNO model with changing climate, and (iii) reservoir performance evaluation using WEAP model and scenarios development. From the trend analysis using Mann-Kendall test, no significant trend noticed for annual, seasonal and for any monthly rainfall. Variation of precipitation shows that number of rainy days is decreasing and number of intense rainy days (more than 100 mm) is increasing. As a result flash floods and dry spells are creating havoc. A significant rising trend with the test statistic value of +3.18 is observed for daily inflow series at 95% confidence level. ARNO result shows that the simulated flow increase/decrease is directly proportional to the change in the rainfall decrease/increase. It is observed that, a change of 25% decrease or increase in rainfall amount resulted in equal amount of decrease or increase in the inflow. The performance of WEAP model shows that if inflows reduced by 20% there would be a decrease in supply reliability, and it would not be possible to increase supplies. Reducing live storage by 10% * influence supply delivered in May and June, but again has little impact on the rest of the year.