Articles | Volume 8, issue 4
https://doi.org/10.5194/se-8-721-2017
https://doi.org/10.5194/se-8-721-2017
Research article
 | 
03 Jul 2017
Research article |  | 03 Jul 2017

Soil erosion evolution and spatial correlation analysis in a typical karst geomorphology using RUSLE with GIS

Cheng Zeng, Shijie Wang, Xiaoyong Bai, Yangbing Li, Yichao Tian, Yue Li, Luhua Wu, and Guangjie Luo

Abstract. Although some scholars have studied soil erosion in karst landforms, analyses of the spatial and temporal evolution of soil erosion and correlation analyses with spatial elements have been insufficient. The lack of research has led to an inaccurate assessment of environmental effects, especially in the mountainous area of Wuling in China. Soil erosion and rocky desertification in this area influence the survival and sustainability of a population of 0.22 billion people. This paper analyzes the spatiotemporal evolution of soil erosion and explores its relationship with rocky desertification using GIS technology and the revised universal soil loss equation (RUSLE). Furthermore, this paper analyzes the relationship between soil erosion and major natural elements in southern China. The results are as follows: (1) from 2000 to 2013, the proportion of the area experiencing micro-erosion and mild erosion was at increasing risk in contrast to areas where moderate and high erosion are decreasing. The area changes in this time sequence reflect moderate to high levels of erosion tending to convert into micro-erosion and mild erosion. (2) The soil erosion area on the slope, at 15–35°, accounted for 60.59 % of the total erosion area, and the corresponding soil erosion accounted for 40.44 %. (3) The annual erosion rate in the karst region decreased much faster than in the non-karst region. Soil erosion in all of the rock outcrop areas indicates an improving trend, and dynamic changes in soil erosion significantly differ among the various lithological distribution belts. (4) The soil erosion rate decreased in the rocky desertification regions, to below moderate levels, but increased in the severe rocky desertification areas. The temporal and spatial variations in soil erosion gradually decreased in the study area. Differences in the spatial distribution between lithology and rocky desertification induced extensive soil loss. As rocky desertification became worse, the erosion modulus decreased and the decreasing rate of annual erosion slowed.

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Short summary
This paper describes methodological experience and provides data references for international counterparts to study soil erosion in karst landform areas. The lithological and desertification factors introduced in the soil erosion model accurately reflect and predict soil erosion conditions and spatial distribution characteristics in karst areas. Future studies on soil erosion in karst areas should include underground loss in the calculation scope.