Location: Southwest Watershed Research
Title: Projected rainfall erosivity changes under climate change from multimodel and multiscenario projections in Northeast China Authors
Submitted to: Journal of Hydrology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 19, 2010
Publication Date: September 30, 2010
Citation: Zhang, Y., Nearing, M.A., Zhang, X.J., Xie, Y., Wei, H. 2010. Projected rainfall erosivity changes under climate change from multimodel and multiscenario projections in Northeast China. Journal of Hydrology. 384(1-2): 97-106. Interpretive Summary: Global climate change is occurring now. Historical weather records over the 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. In this study we looked at projected changes in mean annual precipitation and the power of rainfall to cause erosion (erosivity) for time periods 2030-2059 and 2070-2099 in Northeast China using future precipitation predicted from six GCM models under three green-house gas emissions scenarios (high, medium, and low). Changes were compared to 1960-1999 conditions. Changes in rainfall erosivity were 91%, 71%, and 59% under the three scenarios. Future rainfall erosivity changes may have severe detrimental impacts on soil and water resources in Northeastern China. The impact of this research will be a better understanding of how climate change will affect soil erosion, as well as point out the need for improved land management practices to improve conservation strategies in a future of non-stationary climate.
Technical Abstract: Future changes in precipitation will induce changes in the erosive power of rainfall and hence changes in soil erosion rates. In this study we calculated downscaled mean annual precipitation and USLE rainfall erosivity (R) for time periods 2030 through 2059 and 2070 through 2099 in Northeast China using future precipitation predicted from six GCM models under three emissions scenarios. Changes were compared to 1960 through 1999 conditions. A stochastic weather generator (CLIGEN) calibrated to precipitation for the period 1960 through 1999 was used to temporally downscale the GCM outputs, from which the future R values were calculated. Our results suggested a general increase in erosivity over the region by the late 21st century. Changes in rainfall erosivity under the higher greenhouse gas emissions scenarios, A1B and A2, were the greatest (91% and 71%, respectively). Despite representing reduced emissions pathway relative to present day, the B1 scenario also showed a substantial increase in rainfall erosivity (59%). Multimodel means showed generally larger increases in the northern portion of the region than that in the southern part. Future rainfall erosivity changes will have important impacts on soil and water resources in Northeastern China.