Submitted to: ASA-CSSA-SSSA Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/15/2003
Publication Date: 10/5/2003
Citation: Nearing, M.A., Oneal, M.R., Pruski, F.F. 2003. Soil erosion and conservation implications of climate. American Society of Agronomy-Crop Science Society of America-Soil Science Society of America. p. 812. change. ASA-CSSA-SSSA Proceedings. Interpretive Summary: Global climate change is occurring now. Historical weather records over this last century show that precipitation is increasing both in terms of the number of days we have rain and the intensities of rain. Statistical analyses of the records have indicated that there is a less than one in thousand chance that the changes in these patterns of precipitation could have occurred under a stable climate. We also have good scientific reason to believe that the changes will continue into the next century as well. Parts of the country are expected to become wetter, and parts may become drier. As rainfall changes, so does soil erosion. In this study we used computer simulation models to look at how changes in precipitation might affect erosion rates in the United States. Our results indicate that for every 10% change in total rainfall we can expect a 20% change in surface water runoff and an approximate 17% change in soil erosion. Changes in runoff can have major impacts on flooding, which has been a serious problem in recent years in many parts of the U.S. Changes in soil erosion may mean that we will need changes in our conservation strategies. The impact of this research will be better and more targeted conservation strategies for the future, which will ultimately result in a better soil resource base for growing food in this country.
Technical Abstract: Erosional impacts of climate change involve a highly complex interplay of processes. As the planet becomes warmer, the hydrologic cycle becomes more vigorous. Documented changes in annual precipitation and frequency of high intensity rainfall events show a statistical increase in both, on average, for the United States over the last century. The objective of this study was to evaluate climate change impacts on soil erosion. This study uses results of climate change scenarios from two coupled Atmosphere-Ocean Global Climate Models and sensitivity analyses to investigate the possible levels, patterns, and processes of erosion change that might be expected over the 21st century. Results of this study suggest the potential for changes of rainfall erosivity across much of the continental United States during the coming century. The magnitude of change (positive or negative) across the country over an 80 y period averaged between 16% and 58%, depending upin the method used to make the predictions. Results indicated that, on average, each 1% change in average annual precipitation induced a 2% change in runoff and a 1.7% change in soil loss. Detailed simulations of climate change in conjunction with predicted cropping changes in the Midwest could result in an average increase of erosion rate of 85% over the next 50 years