The evolution of rocky desertification and its response to land use changes in Wanshan Karst area, Tongren City,Guizhou Province, China

• Main Authors: CHEN Huan, BAI Xiao-yong, LI Yang-bing, LUO Guang-jie, XI Hui-peng, RAN Chen, LUO Xu-ling
• Format: Article
• Language: zho
• Published: Agro-Environmental Protection Institute, Ministry of Agriculture 2020-01-01
• Series: Journal of Agricultural Resources and Environment
• Subjects: karst area, land use, rocky desertification, lithology
• Online Access: http://www.aed.org.cn/nyzyyhjxb/html/2020/1/20200104.htm

To understand the correlation between the evolution of rocky desertification and land use changes in the Wanshan Karst area, this study used the supervised classification method to interpret the land use map of Wanshan District, Tongren City, Guizhou Province, China in 2000, 2010, and 2015, as well as the lithology and the contemporaneous rock desert. The superposition analysis aimed to determine the distribution characteristics of each lithology land use, and the percentage of each type of land use that is experiencing rocky desertification, in order to reveal the degree of response of every land use type to rocky desertification. The results showed that from the lithological space, the forest land(as well as shrub land)had the widest distribution area on non-carbonate rocks. The forest land area was up to 142.89 km². In contrast, limestone and dolomite mixed areas were the least, with an area of at least 13.37 km². Rocky desertification had the largest change in the mixed limestone and dolomite areas in 2005-2010, and the rate of change was -1.87 km²·a^-1. Of these, the proportion of mild and moderate rocky desertification in limestone and dolomite areas was the highest, and the rocky desertification that developed on the dolomite clastic rock was the most severe example. Rocky desertification was more likely to occur in carbonate rock areas (Graystone mixed with dolomite, dolomite clastic rock). Analysis of the composition of land that had undergone rocky desertification:Based on the classification of typical rocky desertification and the distribution of rocky desertification in various areas, it was concluded that the land types that had experienced rocky desertification in the study area are mainly dry land and forest land(as well as shrub land). These two types of land had the greatest contribution and response to rocky desertification. The highest occurrence ratio of rocky desertification in these two land types was 20.87% and 4.32%, respectively, whereas the dry land was mainly caused by mild rocky desertification. Additionally, the probability of occurrence was as high as 93.61%, which would provide a reference value for the regionalization of rocky desertification in the study area and better and faster management.