Submitted to: Transactions of the ASAE
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/23/2005
Publication Date: 3/1/2005
Citation: Zhang, G., Nearing, M.A., Liu, B. 2005. Potential effects of climate change on rainfall erosivity in the yellow river basin of China. Trans. Am. Soc. of Agricultural Eng. 48(2):511-517. 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. Changes in runoff can have major impacts on soil erosion and flooding, which has been a serious problem in recent years in many parts of the U.S. and China. This study used output from large General Circulation Models that predict the future of climate under various greenhouse gas scenarios to estimate the potential changes in the power of rainfall (termed erosivity) to cause erosion in the Yellow River, Loess Plateau area of China, where soil erosion rates are extremely high and cause significant downstream pollution problems for China. The results showed significant increase in rainfall erosivity across Yellow River basin for the coming century. The general trend of increases in erosivity decreased from east to west. The average predicted increases in rainfall erosivity ranged from 8 to 30% by the year 2080. Changes in soil erosion may mean that China will need changes in 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.
Technical Abstract: Severe soil erosion in the Yellow River basin is a significant obstruction to the sustainable management of soil and water resources. Any changes in soil erosion will have great effects on long-term planning of soil and water conservation in such a severely eroded basin. Rainfall erosivity describes the soil loss potential caused by rain, which can be expected to change in correspondence to changes in climate. This study was conducted to assess the potential effects of climate change on rainfall erosivity in the Yellow River basin. Two different rainfall scenarios were generated with the HadCM3 general circulation model for the years 2006 to 2035, 2036 to 2065, and 2066 to 2095. The statistics test showed that rainfall erosivity increased significantly in the Yellow River basin under both scenarios for all periods in the coming decades. The erosivity increase varied from scenario to scenario, and from period to period. Generally, increases in erosivity were less from southeast to northwest. The calculated precipitation elasticity of rainfall erosivity indicated that percent changes in rainfall erosivity were greater than percent changes in total precipitation by a factor of 1.2 to 1.4. The expected increases in precipitation require that more attention will be given to soil and water conservation practices such as vegetation rehabilitation and check-dam construction.