Wednesday, November 15, 2006

Impact of Climate Changes on Soil Erosion and Runoff in Korea.

Min-Kyeong Kim1, Dennis C. Flanagan2, Jim R. Frankenberger2, and Charles R. Meyer2. (1) National Institute of Agricultural Science, RDA, 249 Seosundong Kwonsungu, Suwon, South Korea, (2) USDA-ARS National Soil Erosion Research Lab., 275 S. Russell St., West Lafayette, IN 47907

Stochastic weather generators are commonly used to produce the climate input at the appropriate spatial and temporal resolution for detailed of climate change scenarios produced by Global Climate Models (GCMs). These weather generators are particularly useful in producing the climate input required to drive crop, hydrologic, and soil erosion models. CLIGEN is a stochastic weather generator used to produce the climate input for the WEPP (Water Erosion Prediction Project) model. The objective of this study is to apply CLIGEN and adjust CLIGEN parameter values to generate realistic precipitation change scenarios for erosion prediction purposes in Korea. Two different sites, Chun-Cheon and Jeon-Ju, were studied and compared using base observed data from 1966 to 2005. Chun-Cheon is located at a high altitude and is surrounded by forests, and consists of 40% paddy fields and 60% uplands. Jeon-Ju is located in the plains and is 65% paddy fields and 35% uplands. The daily climate data including temperature, precipitation, wind parameters, and solar radiation were applied and compared. Rainfall records in these two regions showed similar trends with significantly higher precipitation during June to August. The increase in the standard deviation was greater than that in the mean, implying greater rainfall variability during wetter periods. Also, we found that a change in precipitation amount had a much greater effect on soil erosion and runoff generation in Chun-Cheon, which has unique topographical characteristics and intense precipitation.