Assessment of Precipitation, Evapotranspiration and Discharge Changes of Kan River Basin, with Regard to Climate Change

One of the impacts of climate change is alteration in water cycles in the different parts of the world. Since the impacts can influence economy and importantly, human health, it is necessary to study effective parameters of human readiness against economic issues, water shortages and so forth in the future. Thus, the present research is conducted to study the process of hydro-climatic changes of Kan River basin. The research examined a 30-year period of 1985-2014 using Mann-Kendall test and linear regression. According to the research results, precipitation and discharge decreased slightly; whereas, evapotranspiration (evaporation and transpiration) followed an ascending trend. In addition, studying the changes within three prospective periods 2030, 2060, and 2090 through GISS-AOM of general circulation model series indicated that evapotranspiration maintains an ascending trend; while, precipitation declines despite volatility in particular periods. Moreover, the average temperature of the area, which is directly related to evapotranspiration, decreases to the mid21st century, and then increases comparing to global mean temperature.