This study examines the impact of climate changes on soil erosion in the agricultural field and the efficiency of a riparian strip in reducing sediment loadings to the stream, via a series of sensitivity analyses with a coupled CLIGEN/WEPP/REMM modeling system. We examined the sensitivity of soil erosion and riparian efficiency to rain intensity, rain probability, riparian buffer width, and riparian vegetation types, with climate data for Athens, GA and Salinas, CA. Based on the analysis results, we have made the following preliminary findings: 1) Soil erosion in the corn field would increase 1.75 to 3.5 percent for each 1 percent increase in annual precipitation; 2) the efficiency of a riparian strip in reducing sediment loadings is more sensitive to rain intensity than rain probability; 3) in order to maintain the riparian efficiency, the riparian width would have to increase by 0.17 to 0.25 percent for each 1 percent increase in annual precipitation; and 4) in order to maintain the same sediment loadings to the stream, the riparian width needs to increase by 0.30 to 0.95 percent of the total hill slope for each 1 percent increase in annual precipitation. Given the fact that annual precipitation has increased by 10% in the past 100 years in most regions of the US, the above results seem to suggest that climate changes would have significant impacts on soil erosion and riparian efficiency in capturing sediments.