Spatial distribution and temporal trends of rainfall erosivity in mainland China for 1951-2010

Abstract

Rainfall erosivity is an important factor for estimating soil erosion rates. Understanding the spatial distributionand temporal trends of rainfall erosivity is especially critical for soil erosion risk assessment and soil conservationplanning in mainland China. However, reports on the spatial distribution and temporal trends of rainfall erosivityfor China, especially of its eight soil erosion regions, are still lacking, which reduces the accuracy of predicting soillosses, assessing soil erosion risks and evaluating the effects of soil conservation measures. Additionally, the lackof the most suitable spatial interpolation method in mainland China, to some degree, has reduced the applicabilityand reliability of the interpolation results. In this study, long-term (1951–2010) daily rainfall data from 756national weather stations were assembled to characterize the spatial and temporal patterns of annual rainfallerosivity across mainland China. Sixteen spatial interpolation methodswere compared to select themost suitableone for accurately mapping the spatial distribution of rainfall erosivity, and theMann-Kendall testwas employedto detect the temporal trends. The results indicated that 1) the universal co-kriging method with the aid of elevationwas superior to the other spatial interpolation methods; 2) long-term average rainfall erosivity increasedfromthe northwest to the southeast, ranging from31 to 30,051 MJ mm ha⁻¹ h⁻¹ a⁻¹; 3) overall, rainfall erosivityacross China and water erosion regions experienced an insignificant increasing trend over the study period. Significantdecreasing trends were observed in the northwest Loess Plateau region (0.01 level), the northeast blacksoil region and the north earth and gravel mountain region (0.05 level). Significant increasing trends (0.05 level)were found in the southern red soil hilly region and the southwest Karst region; and 4) two lineswere identifiedaccording to the temporal trends of rainfall erosivity from the east to the west. In total, this study offers usefulinformation both for soil erosion prediction and land management practices of mainland China.

Citation

Qin, Wei; Guo, Qiankun; Zuo, Changqing; Shan, Zhijie; Ma, Liang; Sun, Ge. 2016. Spatial distribution and temporal trends of rainfall erosivity in mainland China for 1951-2010. CATENA, Vol. 147: 10 pages.: 177-186.  10.1016/j.catena.2016.07.006