Impacts of Future Climate and Land use Change on Water Yield in Arpa Catchment

Abstract

Studying the interaction between hydrology, land use, and climate change is necessary to support sustainable water resources management. In this study, we assessed the effects of both land use and predicted climate change on the Arpa Catchment water yield using the ArcSWAT model. The influence of changing climate on water yield was evaluated for different emission scenarios using CMIP6 Global Climate Models (GCM). Three GCM namely BCC-CSM2- MR, EC-Earth3-Veg and NorESM2-LM were ensemble and used for this study. Two ‘Shared Socioeconomic Pathways’ (SSP) scenarios (SSP.2_4.5, and SSP.5_8.5) were used for future climate prediction in the current study area. Land use land cover, meteorology and soil type data used as inputs to analyze the spatial and temporal pattern of water yield in the Arpa catchment from 1990 to 2020 and the impact of land use change on water yield in the basin simulated with ArcSWAT Model. Water yield compare to baseline scenario (1990) increased by 98.36 mm (18.48%) in decadal year 2000, increased by 144.51 mm (27.15%) in year 2010 and in decadal year 2020 water yield increased by 154.20 mm (28.98%). Climatic scenario (SSP2_4.5 and SSP5_8.5) changes in water components were simulated with ArcSWAT model. Model was run for three future time slices i.e. Near future (2030s), Mid future (2060s), and Far future (2090s). Water yield with reference to baseline period (646.02 mm) increased by 71.69% under SSP2_4.5 during 2090s. Similarly, under SSP5_8.5 water yield increased by 106.87% for the far future (2090s).