关键词: 镶嵌体结构, 景观, 分形, 洞庭湖区

Abstract: Dongting Lake Area, located in the middle reaches of Yangtze River, lies between 27°55′~30°23′N and 110°50′～113°45′E, and consists of 17 counties with an area of 28 737 km2. Because of nonrational anthropogenic exploitation and utilization, the landscape pattern has changed remarkably in this area. Based on the TM image in 1980, 1990 and 2000, fractal dimension values of each landscape of the mosaic structure were analyzed for Dongting Lake Area under the support of RS and GIS technology and landscape ecology methods. It is indicated that the landscape pattern changed remarkably among cultivated land, water area and construction land. The fractal dimension of each landscape element among the five types was different from that of the other one. Each landscape factor can be ranked according to the fractal dimension of the mosaic structure: cultivated land < unutilized land < construction land < water area < forest < lawn. The fractal dimension of construction land approached to 1.5, which was the most unstable landscape element. On the contrary, the dimension of the lawn and forest changed gently, and it was the most stable landscape element. The simulative result by fractal model showed that the mosaic structure of natural landscape was influenced by physiognomy: the fractal dimension of cultivated land, construction land and water area increased along with the rise of altitude and vice versa is the dimension of lawn and forest. It is shown that physiognomy, hypsography, position and humankind affect the fractal dimension of landscape.

Key words: mosaic structure, landscape, fractal dimension, Dongting Lake Area