MODELING THE IMPACTS OF CLIMATE CHANGE FOR IRRIGATION WATER MANAGEMENT : A CASE STUDY ON LOWER BHAVANI SAGAR PROJECT COMMAND AREA, TAMIL NADU

Abstract

This thesis evaluates the Reliability (time & volume), vulnerability, and resilience of the Lower Bhavanisagar Reservoir, Erode, Tamil Nadu, a multipurpose reservoir that served as a critical source of water for industries, irrigation, hydroelectric generation and environmental preservation. Future impacts of the climate change on the water availability are recognized and for which the effective management strategies to improve the efficiency and capacity of the reservoir for various purposes are derived. Rule curves are being generally utilized to manage efficiently the reservoirs, ensuring the demand is met throughout the drawdown-refill cycle. The study proposes a framework for analysing the extent of climate change including the present and future periods and improving the Adaptive Management of water resource systems. Special attention to institutional setups is recommended to speed up the process of implementing Adaptive Management. Hydrologic models, such as SWAT, are used to model the catchment runoff yield, and also providing a better understanding of the historical, current, and future scenarios related to the change in reservoir inflow behaviour. The efficiency of SUFI-2 and other techniques for hydrologic model uncertainty analysis, calibration, and validation are explored, with SUFI-2 often proving the most effective method. The study aims to design an optimal hedging strategy based on the simulated historical and climate change-affected hydrology to ensure the reservoir's optimal performance. The study concludes that effective control operation of reservoirs is essential to ensure that the allocation of available water results in optimal system performance. Despite facing challenges, the water resource officials and farmers in the Lower Bhavanisagar Reservoir system have shown a positive attitude towards minimizing the climate change impacts on the irrigation and other uses of water. Therefore, the recommendations of the study presented here will assist in more scientifically informed way to cope up with future climate impacts improving the resilience and adaptability.