Preliminary design and application of karst rocky desertification comprehensive treatment on small watershed based on the 3S-CAD technique— A case in the Xiaoshan Small Watershed, Tiandeng County

In order to improve rocky desertification treatment in karst areas, a preliminary design for Tiandeng County in Guangxi is made by means of the 3S-CAD technique. The design, a case in the Xiaoshan Small Watershed, comprises the RS in interpreting the basic geographic information, the GIS in digitizing, managing, analyzing and outputting the data, and GPS in locating the sample plot during field survey and the CAD in carrying on engineering drawing. According to the design and field survey, it is determined that the comprehensive treatment of rocky desertification mainly includes forest conservation (805hm2 of hillside), reforestation ( 46hm2 of land), diversion canal for water conservancy ( 7 462m long) and forage grass planting ( 330m2 of land). General arrangement of the project adopts the combination of sub-projects in small patches of land, line-formed land and overall layout on the whole area, which enables the reforestation and water conservancy as well as animal husbandry projects support with each other. Compared with the traditional methods, the 3S-CAD technique is characterized by speedy design and scientific and reasonable layout for project.