Research of Fractal Dimension Based on Classification of Karst Basin Contours

Karst basin as a relatively independent hydrological and geomorphological system is composed of different sub-units. The ecological environment conditions of each unit have both internal relations and obvious differences. so it is difficult to conduct ecological governance in the same way. By using GIS technology, automatic extraction and multicomponent auxiliary correction were used to determine the basin boundary, fractal theory was adopted to classify the basins, and the characteristics of each type of drainage basins were analyzed in combination with slope, undulation, vegetation cover and land use. The results show that: (1) The problem of boundary inconsistency between above-ground and underground drainage basins in karst basin is solved by using the method of correcting the basin extracted automatically from the surface basin. (2) According to the calculated average fractal dimension of contour line of each river basin, and combined with the geomorphological characteristics of each river basin, the dividing threshold of each river basin was determined, and the fractal dimension value greater than or equal to 1.64 was divided into the first type of river basins. The fractal dimension between 1.64 and 1.74 is the second type of basin. The fractal dimension value greater than or equal to 1.74 is divided into the third type of basin. (3) Three karst basins of different types have different landforms, vegetation cover and land use, which provide theoretical basis and technical support for the control of rock desertification in accordance with local conditions.