Response of streamow to climate variability and human activity in Kashkan river basin

Climate change and anthropogenic effects are two main drivers of stream flow changes. In this study، the trend and Fluctuations in hydro climatic data series of Kashkan River were evaluated during 1972-2011. Then، the climate elasticity method was used for quantitative assessment of stream flow response to climate variability and human activity. Results revealed that if precipitation decreases by 10%، runoff will decrease by 25. 7∼25. 1 percent، and if potential evapotranspiration decreases by 10%، runoff will increasing by 15. 7∼15. 1 percent. In 1999-2011، human activity was the main factor that decreased the amount of runoff in Kashkan river basin. The contribution of human activities were 73. 97∼74. 22 percent، while the increasing percentage due to climate variability accounted for 25. 77∼26. 02 percent، showing that runoff in the Kashkan river basin is more sensitive to climate variability than human activities. The results of this study can provide a reference for the development، utilization and management of the regional water resources and ecological environment protection.