A Research On Fractal Dimensions Characteristics Of Landform Based On DEM

Fractal idea has infiltrated many fields step by step, and abundant research productions had been obtained along with the development of fractal theory, moreover, the application of fractal theory in geography specially in Geomorphology provided new ideas and powerful tools especially for many natural forms which were not easy to expressed by traditional geometric forms. DEM is the widely-used data format to describe landform and physiognomy at present. This thesis taken the seven districts of the Loess Plateau of North Shaanxi Province as the research area and discussed the relief meaning, methods and scale effect of the DEM Fractal Dimension and Gully Fractal Dimension on the basis of summarizing the formers' research results and experiences extensively. First, three methods to calculate DEM Fractal Dimension were dissertated, through comparing, achieved the perfect model and the effect of scale to DEM Fractal Dimension, as well as the spatial distribution law in the Loess Plateau of North Shaanxi Province were expatiated. Second, two extraction models about Gully Fractal Dimension were established. The dissertation analyzed profoundly the relief meanings that Gully Fractal Dimension contained, and probed into the effect of scale to Gully Fractal Dimension and the spatial distribution law through the comparison with gully density. According to the results of experiments, DEM Fractal Dimension and Gully Fractal Dimension can reflect the complexity of terrain as a macroscopical factor and quantify the topographical information and explain the spatial distributing of landform, and they are lower as the DEM's scale is smaller. At last, DEM Fractal Dimension and Gully Fractal Dimension provided the method to reflect synthetically the terrain types and characteristic in many ways, and taken on the important meaning to research in interrelated knowledge.