Variability of Rainfall Erosivity and Erosivity Density in the Ganjiang River Catchment, China: Characteristics and Influences of Climate Change

Xianghu Li,Xuchun Ye

doi:10.3390/atmos9020048

Abstract

Soil erosion is one of the most critical environmental hazards in the world. Understanding the changes in rainfall erosivity (RE) and erosivity density (ED), as well as their affecting factors, at local and catchment scales in the context of climate warming is an important prerequisite of soil erosion prevention and soil loss risk assessment. The present study identified the variability and trends of RE and ED in terms of both time and space in the Ganjiang River catchment over the period of 1960–2012, and also analyzed and discussed the impact of climate change. The results show that RE and ED in the catchment had great monthly variations and high year-to-year variability. Both presented long-term increasing trends over the entire study period. The highest RE and ED were observed in June and in the eastern and northeast parts of the catchment, which indicated that June was the most susceptible month for soil erosion in this area and the lower reaches of the Ganjiang River was the riskiest area for soil erosion. Finally, the East Asian summer monsoon and climate change were highly correlated with changes in RE and ED.

Highlights

Soil erosion by water is one of the most important land degradation problems and a critical environmental hazard in modern times, and it has severely restricted the development of global society and economy [1]
As a numerical description of climate impact on soil loss, rainfall erosivity (RE) is one of the most important factors used in the Universal Soil Loss Equation (USLE) and RUSLE [13,14]; it combines the influence of precipitation duration, magnitude, and intensity [15] and can directly reflect the potential of soil erosion caused by rainfall [11,16]
With the beginning of the rainy season in the Ganjiang River catchment in April, the monthly rainfall erosivity increased quickly from January and reached its peak from April to June, sharply decreased in July; RE became very small after September when the catchment began its dry season and lasted through December

Summary

Introduction

Soil erosion by water is one of the most important land degradation problems and a critical environmental hazard in modern times, and it has severely restricted the development of global society and economy [1]. The Universal Soil Loss Equation (USLE) [11] and its revised form (RUSLE) [12] are the most widely used methods for predicting and evaluating soil erosion worldwide [10]. As a numerical description of climate impact on soil loss, rainfall erosivity (RE) is one of the most important factors used in the USLE and RUSLE [13,14]; it combines the influence of precipitation duration, magnitude, and intensity [15] and can directly reflect the potential of soil erosion caused by rainfall [11,16]

Objectives

Methods

Results

Discussion

Conclusion