Factors influencing the evolution of human‐driven rocky desertification in karst areas

Abstract

AbstractKarst rocky desertification has become one of the most important e‐environmental problems in China. The mechanisms of rocky desertification caused by land resources use, settlement expansion, population growth, and corresponding ecological responses are unclear. High‐resolution images of a typical karst plateau (Houzhai River Basin) acquired in 1978, 2005, and 2010 and data samples collected in the field in 2015 were used to quantitatively study the factors governing the evolution of rocky desertification driven by human activities. They comprehensively reveal its causes and influencing factors. Results suggest that the rocky desertification in the eastern and southern parts was, generally, more severe than in the western and northern parts of the study region. In the period from 1978 to 2015, no significant changes in the degree of (moderate) rocky desertification were observed. However, decreasing trends were observed for the no‐rocky areas, and slight decrease in rocky areas. The comprehensive indices of rocky desertification in 1978, 2005, 2010, and 2015 were 1.33, 1.24, 1.22, and 1.24, respectively. The rock outcrops in the no‐rocky desertification and potential rocky desertification areas were closely associated with the gravel content, slope gradient, and soil thickness, whereas those in the slight, moderate, and severe rocky desertification areas were primarily associated with the land use, gravel content, and slope gradient. The results suggest that the land use and human settlement were important factors determining the rocky desertification. The rocky desertification in the study area has improved during the period from 1978 to 2015. The main contribution to this improvement originated from the change in land use patterns. Therefore, reasonable management of land use and human settlement distribution can effectively reduce the rocky desertification in a karst area.