Spatio-temporal variation in rainfall erosivity during 1960-2012 in the Pearl River Basin, China

Accelerated soil erosion is an undesirable process that adversely affects the conservation of water and soil. Rainfall erosivity is used to measure the potential ability of rain to cause erosion. This study explores spatio-temporal variations in rainfall erosivity in the Pearl River Basin of China during 1960-2012, at annual and seasonal scales based on a daily model proposed by Yu. Analysis methods including linear regression, Mann-Kendall and the Kriging interpolation technology were applied to determine fluctuating spatial and temporal patterns. Yu's model was proven suitable for the Pearl River Basin by comparison with another model proposed by Zhang. Computation results show an average annual rainfall erosivity of 9918.98 MJ.mm/(hm(2).h) and that the Pearl River Delta region, most regions of the Dongjiang River Basin, and the Beijiang River Basin were all under considerable threat from rainfall erosion. The annual rainfall erosivity of the basin does not show significant or abrupt changes, and has fluctuated moderately over the past few decades. The rainfall erosivity of the basin shows an upward trend, and the probability of water and soil erosion caused by rainfall was increasing overall. The problem of water and soil loss in the Pear River Basin remains severe due to aggravating vegetation deterioration, rocky desertification, and climate change. Relevant response strategies and appropriate measures must be considered to guard against further deterioration of the basin. (C) 2015 Elsevier B.V. All rights reserved.