Qualitative risk assessment of soil erosion for karst landforms in Chahe town, Southwest China: A hazard index approach

• Soil erosion by water is studied using qualitative model.
• Spatio-temporal characteristics of the erosion are examined using erosion hazard index.
• Low and moderate erosion risks characterize most of the study area.
• Vegetation recovery and erosion remediation are found in a progressive pace.
• Innovations of agricultural practice are indispensable for future erosion recovery.

Accelerated soil erosion, rocky desertification and land degradation are three major threats to sustainable agricultural and regional development in karst landscapes, especially in developing countries. Soil erosion mapping is indispensable for monitoring such environmental changes. In Chahe town, Guizhou, southwest China, the karst area has suffered severe soil erosion in the second half of the twentieth century. In order to understand the erosion situation and conduct risk evaluation, erosion factors such as rainfall, vegetation cover, slope, land cover and soil type were integrated by combining spatial data of four different years and using GIS and remote sensing (RS) techniques to evaluate and map erosion risks. The soil erosion hazard analysis indicates that an average of 42% of the study area was covered by the moderate erosion throughout the study period. Understanding the spatial and temporal patterns of accelerated erosion helps to identify appropriate mitigation measures, and suggests that remediation of the karst landscape is progressing slowly, with considerable potential for further recovery.