Modelling the Impact of Climate Variability and LULC Changes on the Hydrological Processes in the Upper Jhelum Basin Catchment, Western-Himalayas
Durdanah Mattoo, Sajad Ahmad Mir, M. Sultan Bhat, Akhtar Alam, Nusrat Rafique
Abstract
Abstract Climate variability and Land use practices significantly alter the hydrological processes at local and regional levels. The Upper Jhelum catchment is an important Himalayan catchment which is the head-water region of the river Jhelum. The focus of this study is to examine the impact of climate variability and land use land cover dynamics on the hydrological regime in the study area. This study used the physically based distributed hydrological model, Soil and Water Assessment Tool (SWAT) to assess the individual and combined contribution of climate variability and Land use/Land cover changes on the hydrological processes operating on multiple sub-watersheds of the region. The model was calibrated and validated for multi-site monthly stream flow. The R2, ENS and PBIAS values ranged from, 0.71–0.81, 0.56–0.88, and 0.74–0.94 respectively for calibration and 0.69–0.8, 0.51–0.87, and ‒2.3–10.2 respectively for validation. To study the separate and combined effects of climate variability and land-use, we set up the model for four scenarios of different combinations of land use maps and climate data. The results reveal the change in land use has led to increase in the evapotranspiration rates. While all other hydrological processes (Groundwater Flow, Surface Flow and Water yield) were more sensitive to climate variability and it has led to an overall decrease in the water resources of the region. A peculiar trend of the left bank watersheds being more sensitive to the landuse change in addition to climate variability was also strongly depicted in the results.