Fractal Dimension Dynamics and Land Use in the Lake Dianchi Watershed from 1974 to 2008
滇池流域1974年至2008年土地利用的分形动态

Here, we use remote sensing and GIS techniques to monitor the fractal dimension dynamics of land use patterns in the Lake Dianchi watershed from 1974 to 2008. Our aim is to provide a theoretical basis for land use policy across the Dianchi watershed and coordinate urban development and lake ecosystem protection in this plateau lakeside city. We found that the morphology of each land use within the Dianchi watershed takes on fractal dimension characteristics. Ranked from high to low, the fractal dimension can be ordered by vegetation class (including wild grassland, agricultural land and forest), bare land and built-up areas, and water. The fractal dimension of the whole watershed landscape has been gradually rising, is approaching the critical value of 1.50, and structural stability continues to decline towards an unstable state. Both the fractal dimension of agricultural land and built-up areas gradually increased then slightly decreased, opposite to that for wild grassland. The fractal dimension of forest increased, and the fractal dimension of bare land and water decreased. Land use changes resulting from the occupation and supply of agricultural land during the process of urban sprawl is the main driving force behind fractal dimension dynamics and structural stability in the Dianchi watershed. Therefore, regional land renovation policy should aim to control increases in fractal dimension. The spread of urban built-up areas should also be controlled, and more attention should be paid to the renewal of old town areas. Agricultural land distributed in patches across the transition zone between forest and wild grassland should be returned to forest and grass.