Spatial distribution and temporal trends of rainfall erosivity in mainland China for 1951-2010
| Authors: | Wei Qin, Qiankun Guo, Changqing Zuo, Zhijie Shan, Liang Ma, Ge Sun |
| Year: | 2016 |
| Type: | Scientific Journal |
| Station: | Southern Research Station |
| DOI: | https://doi.org/10.1016/j.catena.2016.07.006 |
| Source: | CATENA |
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 conservation
planning in mainland China. However, reports on the spatial distribution and temporal trends of rainfall erosivity
for China, especially of its eight soil erosion regions, are still lacking, which reduces the accuracy of predicting soil
losses, assessing soil erosion risks and evaluating the effects of soil conservation measures. Additionally, the lack
of the most suitable spatial interpolation method in mainland China, to some degree, has reduced the applicability
and reliability of the interpolation results. In this study, long-term (1951–2010) daily rainfall data from 756
national weather stations were assembled to characterize the spatial and temporal patterns of annual rainfall
erosivity across mainland China. Sixteen spatial interpolation methodswere compared to select themost suitable
one for accurately mapping the spatial distribution of rainfall erosivity, and theMann-Kendall testwas employed
to detect the temporal trends. The results indicated that 1) the universal co-kriging method with the aid of elevation
was superior to the other spatial interpolation methods; 2) long-term average rainfall erosivity increased
fromthe northwest to the southeast, ranging from31 to 30,051 MJ mm ha−1 h−1 a−1; 3) overall, rainfall erosivity
across China and water erosion regions experienced an insignificant increasing trend over the study period. Significant
decreasing trends were observed in the northwest Loess Plateau region (0.01 level), the northeast black
soil 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 identified
according to the temporal trends of rainfall erosivity from the east to the west. In total, this study offers useful
information both for soil erosion prediction and land management practices of mainland China.