Assessment of impact of changing climate on performance of a system of reservoirs in India

This study attempts to assess impact of climate change on performance of Damodar Valley Corporation reservoir system in India. Reservoir operation simulations were executed using HEC-5 model with existing and projected demand. The simulations were carried out with normal storage, reallocated storage for baseline (2000-2005) and projected (2018-2030) period using LMDZ-IITM-RegCM4 under CORDEX-SA for RCP 4.5 scenario. Inflow to the reservoirs was generated using HEC-HMS model. Overestimation of mean and underestimation of standard deviation of simulated streamflows for baseline period was noted for most of the reservoirs and barrage with some exceptions. The study indicated decrease of performance (compared to baseline period) of Maithon, Panchet and Tenughat reservoirs with existing demand in Season-1 (June-Sept) for some future years and also in Season-2 (Oct) for all reservoirs for all future years. As obvious, with projected demand performance of reservoir system turned out to be poorer than that with existing demand for all reservoirs for all seasons for all future years. Reallocation of reservoir storage volume led to improvement of performance of reservoir system in Season 1, Season 3 (Nov-Dec) and Season 4 (Jan-May) for all future years. As regards flood control operation, 100% reliability was noted for future years.