Predicting the impact of future climate change on streamflow in the Ugam River watershed

Climate change affects the environment and human life across the planet and it is expected that the negative consequences will be large, especially in developing countries, such as Uzbekistan. The objective of this study was to predict the impact of future climate change on the streamflow of Ugam watershed (Chirchik River Basin (CRB)) using the Soil and Water Assessment Tool (SWAT). The outputs of Coupled Model Intercomparison Project Phase 5 (CMIP5), in combination with Representative Concentration Pathway 8.5, were used as future climate records for the period 2019−2048. The SWAT model was calibrated and validated for the streamflow from Ugam watershed through using the observed daily flow data from 2007 to 2011. The calibrated SWAT model was used to simulate the impact of future climate change on streamflow in the Ugam River for 2019−2048. The results show that the stream discharge is expected to decrease by approximately 42% within thirty years, with a 1.4 °C increase in temperature and 286 mm decrease in precipitation. The peak point for the future period is 40.32 m³ /s in 2037 whereas the lowest discharge, predicted for 2048, accounts for 22.54 m³ /s. Our study enables to understand the impact of climate change on water resources in the Ugam river and to increase the adaptive capacity of water users and managers in the region.