Modelling the Future Impacts of Climate Change on Watershed Suspended Sediment Transport

Climate change is one of the most important challenges that influenced different parts of human life on the earth. Evaluation of climate change phenomenon and its possible outcomes on hydrological processes can decrese the challenges of managers and planners of water resources in the next period. The main aim of this study is to evaluate the effect of climate change on sediment output of Sharekord watershed basin (2046-2065 period). In this research, SWAT distribution model was used to study the impact of climate change on Shahrekord watershed basin hydrology. SWAT was calibrated and accreditated for the base period of 2002 to 2010. In order to evaluate the effects of climate change and global warming on the basin sediment during 2046-2065, HadCM3 climate model data was subscaled under scenario of A1B, A2 and B1 using LARS. In continuation, downscaled climate data were introdued to SWAT model and sediment changes in the next period were estimated. Results show that climate and hydrology variables of Shahrekord basin will have remarkable changes in the next period. Comparison between observed and simulated climate parameters in 2046-2065 period show that the temprature of region will increase in different months between 1.1 to 2.6 ºC compared to the baseline. Precipitation will have also a change between -30 up to 18 precent, except during the months of low rainfall. It can affect the total quantity of available water, the peak and extreme events. Results of simulations also show the sediment variations between 500 and -90 percent.