Simulation of soil erosion under the influence of climate change scenarios

Climate change is known as the long-term average changes of weather conditions in an area with significant effects on the ecosystem of the region. Climate change is believed to have significant impacts on the water basin and region, such as in a runoff and hydrological system, erosion, environment as well as agriculture. Climate change simulation and scenario design can serve as a useful tool in reducing the effects of this phenomenon. The objective of this study is to simulate climate change and design different scenarios in order to evaluate the site-specific impacts of future climate change on soil erosion at the Kasilian watershed in the north of Iran employing seven downscaling scenarios. Hence, the climate changes were downscaled based on A2 and B1 emission scenarios, using the Institut Pierre Simon Laplace (IPCM4) with Long Ashton Research Station Weather Generator model and three climate change scenarios, i.e., 10% increase in rainfall, 10% reduction in rainfall and unchanged rainfall were employed by Statistical Downscaling Model for the periods of 2011–2030 and 2031–2050. Also, the Revised Universal Soil Loss Equation (RUSLE) model was used in order to estimate soil erosion in basis period (1991–2010) and in the simulated periods (2011–2030, 2031–2050) under effect of climate change scenarios. The results showed that the rainfall erosivity factor in the RUSLE model is directly influenced by climate changes. The mean of soil erosion was 21.82 (tons ha⁻¹ year⁻¹) in basis period, and there was an increase of 10–35% for rainfall erosivity and 10–32% for soil loss during 2011–2030, compared with the present climate. Simulated soil loss under the rainfall erosivity during 2031–2050 would be 4–28 and 2–26% for soil loss compared with those under seven downscaling scenarios in the present climate. Thus, increase in soil erosion will be definite in four future decades.