INFLUENCE OF HYDROMETEOROLOGY AND CATCHMENT CHARACTERISTICS ON KALLADA DAM, KERALA

Abstract

Dams are impacted by climate change in many ways. Larger spillway capabilities will be required to manage greater peak flows as a result of an increase in extreme precipitation events and floods. In certain situations, despite an increase in rainfall, climate change might also result in less drainage, which can leave reservoirs with less water. Climate change is predicted to have an impact on a number of dam-related aspects, including the definition of downstream consequences and incoming floods. Therefore, it is necessary to break down the effects of climate change in the several areas that combine the risk of a dam in order to analyze their effects on the overall safety of a dam. It is well accepted that modifications to the catchment area's use directly affect the water environment's quality. Sediments and nutrients from the catchment region are distortedly outflow in rivers with dams and reservoirs. The purpose of this study is to comprehend an examination of the impact of hydro meteorological data and catchment parameters on the dam's capacity. Reservoir sedimentation is the process by which the streamflow carries and deposits the sediments into the reservoirs. One of the main causes of reservoir sedimentation is anthropogenic soil erosion in catchment areas. For this study, Kerala, Kallada dam was selected and study is focused on the main issues of the Kallada dam due to sedimentation based on the hydro meteorological data and catchment characteristics and using Empirical Area Reduction Method. Sedimentation is a major challenge for reservoir and dam management because it has detrimental consequences on the environment and the economy globally. On the other hand, reservoir sedimentation can be significantly decreased by controlling the rates of sediment loss throughout a watershed. This study sheds light on the regional heterogeneity of sediment loss rates at the watershed scale through a case study, highlighting an assessment method for maintaining successful soil conservation policies. In a case study for the Kallada reservoir in Kerala, the assessment approach uses the Modified Universal Sediment Loss Equation (MUSLE) and the Soil and Water Assessment Tool (SWAT) to quantify sediment losses. In the reservoir basin under study, upstream inflows were simulated using the SWAT model. The results of the goodness-of-fit analyses indicated that the watershed behavior was realistically represented, and the Nash-Sutcliffe values are found to be 0.868 which were satisfactory. Key words: Empirical Area reduction method, DEM, Soil map, LULC, SWAT, Calibration and Validation.