Discussing the genesis of karst rocky desertification research based on the correlations between cropland and settlements in typical peak-cluster depressions

Abstract

This paper attempts to explain the theoretical reasons why local farmers have executed land mismanagement measures such as steep slope land cultivation, in order to reveal the mechanisms of karst rocky desertification (KRD, including light KRD, moderate KRD and severe KRD) through typical case studies. Firstly, this paper assumes that the low land capacity is the initial cause of KRD in peak-cluster depression areas. Furthermore, the ecological quality of the peak-cluster depression zone (a combination of clustered karst cones with a common base and depressions between cones) is influenced by the relationship between the area of depressions and the population of residential areas. Therefore, six typical peak-cluster depression areas of Guizhou province were selected to compare the distribution circumstances of cropland, the characteristics of settlements and the formation of KRD with the help of ALOS images in 2010 (with a resolution of 10 m × 10 m). The results show that there is a negative correlation between the percentage of the cultivated land and the percentage of KRD at peak-cluster depressions. The relationship could be concluded by three situations of the process of KRD, which are low, middle and upper carrying capacities of land. Severe KRD is only distributed in peak-cluster depression areas with less flatland, low land capacity and a high population. The harmonization between population pressure and bearing capacity of land will influence the ecological qualities in the peak-cluster depressions. The KRD phenomenon which occurred in six typical peak-cluster depression areas confirms that the hypothesis suggested by this paper is correct, and this result will contribute to understanding the natural mechanisms of KRD and guide the ecological restoration of KRD land.