Assessment on erosion risk based on GIS in typical Karst region of Southwest China

Abstract

ABSTRACT This study evaluates the potential danger of soil erosion with regard to the current poor situation in the typical karst area of Anshun City in Guizhou Province (China) and provides a reference for the prevention and control of soil erosion in karst areas. The criteria of the Standards for classification and gradation of soil erosion and Techniques standard for comprehensive control of soil erosion and water loss in karst area in non-karst and karst areas, respectively, GIS, and high-resolution remote sensing image interpretation results of land use are used to explain the intensity of soil erosion and soil loss tolerance. Results show that soil erosion rate calculated by different standards in the karst area is consistent with the monitoring value. The average erosion modulus of Guizhou Anshun is 446.83 t/(km2·a), the soil erosion area is 2,861.01 km2 with a ratio of 30.9%, the soil erosion potential danger index (SEPDI) value is relatively small and mainly includes free- and light-danger types, and the average SEPDI value is 1.7. The soil erosion control project of Anshun City can range according to the SEPDI level of villages, which can be comprehensively managed from high to low. Soil erosion prevention and control in karst areas should use SEPDI as the core indicator rather than soil erosion intensity grade.