Re-discussion on the concept and classification of rocky desertification

Earlier studies considered that the rocky desertification happened during the human history period and in the subtropical area,which resulted from anthropogenic unreasonable economic activities.But this point ignored that the rocky desertification would occur in other possible period and location,result from other reasons.This article corrected the concept of rocky desertification,considered that rocky desertification is the process of land degradation with similar to rocky desertification landscape which formed by degeneration of vegetation in the earth's surface,erosion of soil,loss of surface water and the outcropping of bedrock under moist and semi-moist climatic environment and karst environment,due to the factors of human activity and(or) changes of climate etc.The article also explained for its connotation.According as the theory of ecological datum plane,we brought land classification and synthetic landscape indications of rocky desertification,classified the rocky desertification lands into four grades as light,middle,serious,and super serious,graded each rocky desertification land with indexes which including rate of outcrops,form of karst physiognomy,gradient of the earth's surface,thickness of soil,coverage degree of mantle rock,degree of soil erosion,coverage rate of vegetation,plant and types of land use.It also put forward the land classification and their synthetic landscape indications of rocky desertification land by taking the karst mountainous area of north Guangdong as example.