Experimental Study on Coupled Stress-Dissolution of Carbonate Rocks in Rocky Desertification Area of Karst Plateau, Guizhou, China

Abstract

The karst rocky desertification is one of the major bottlenecks for the eco-environmental safety and economical sustainable development in karst areas of China. The formation of rocky desertification is influenced by many factors, and the lithology of carbonate rocks has the most profound influence on it as internal factors. The lithological difference of carbonate rocks determines its weathering process and the way of the accumulation and loss of surface soil, which makes the origin, temporal and spatial evolution rule and governance difficulty of rocky desertification different. In this paper, the limestone and dolomite in the moderate and severe rocky desertification region in the Guizhou plateau are selected as the research objects. Stress-dissolution experiments of carbonate rocks are carried out by the simulating open system of the water environment of epikarst zone. The differences in deformation and dissolution characteristics of limestone and dolomite under different stress conditions are analyzed. In addition, the characteristics of surface and internal pore structure of the rocks are analyzed from the microscopic view. The results further explain why the degree of rocky desertification in the dolomite area is lighter than the limestone area, but it is more difficult to control than the limestone area. These results provide a theoretical reference for the controlling of rocky desertification.