Dams and their safety under the extreme climate conditions: study of dams on Godavari River

The climate change effects on the variation and distribution of precipitation at 15 vital dam sites (large dams) located over the Godavari River Basin (GRB) are investigated in this study. The Time-Varying Downscaling Model (TVDM) technique is employed for this purpose. The data for daily rainfall at 0.25 × 0.25 degrees grid size are obtained from IMD, Pune. The CanESM2 outputs were considered as predictor variables. The calibration and validation of TVDM was carried out using the historical rainfall data (1951–2010). Next, the future variation (2011–2100) of rainfall over the GRB is analyzed using three Representative Concentration Pathway (RCP) climate change scenarios viz. RCP2.6, 4.5 and 8.5. Further, the extreme rainfall events which are generating the floods in the selected locations are analyzed using the extreme percentile values (90th and 95th). The variations of these extreme values in the future (2011–2100) are judge against the baseline (1971–2000) data for analyzing the possible impacts of climate change. The results reveal that the magnitude and the count of extreme events are expected to intensify in the future period. In comparison with the baseline data, all the study locations are expected to experience an increase of 3.61–38.93% in the 95th percentile values according to the RCP8.5 scenario. Furthermore, rainfall frequency analysis is also conducted to evaluate the potential hazards associated with flooding. The results show that the extreme events are more frequent with high magnitude during the future period compared to the baseline data. It implies a vulnerable situation to most of the dams in the GRB during the future period and effect will be worst as per RCP8.5 scenario. The outcomes of this research are expected to aid stakeholders to develop good strategies for safeguarding through the better maintenance, management of the dams and reservoirs in the wake of Climate Change.