Modeling of the effects of climate change on rainy and gully erosion potential of Kor-chamriz watershed in Fars province

Abstract

Role of climatic factors is significant among the factors affecting the erosion of watersheds. The importance of this issue increases with regard to the phenomena of climate change. Therefore in this study using different scenarios of climate change, rainy and gully erosion potential of Kor-chamriz watershed in Fars province was studied applying Arnoldus and Sepaskhah`s methods of humidity-soil for statistical period of 2002–2060. It should be noted that he output of general circulation climate models (HadCM3) were used to stimulate temperature and precipitation data and they were downscaled using Lars-WG software. Results of this study show that the based on scenarios of A1B and A2, basin`s precipitation will increase and according to various scenarios, the annual temperature changes for the stimulated period have increased 0.32–0.51 degrees in comparison with the basic period. Then, every three scenarios of climate change, especially A1B indicates an increase in the potential of gully erosion occurrence based on WS index compared to the basic period. The Results of this study show that according to the statistics of basic period of 1988–2010, the ratio between extracted rainy erosion from Arnoldus formula to the real erosion data has been 19 % that this amount was calculated to be 3 % for Sepaskhah method. Also all scenarios of future climate change confirm decreasing trend of rainy erosion based on two observational methods and three proposed climate change scenarios. Therefore, it is expected that in the coming decades the ratio of rainy erosion compared with real erosion of the whole basin will decrease.