The study on landscape pattern change of wetland based on GIS and RS: An example of Dongting Lake area

摘要

As one of three important ecosystems in the world ,wetland has complex , various and specific functions. With the change of its component ,the wetland ecosystem function is changing . Analyzing the process of wetland landscape change can expose the mechanism and rules of wetland landscape change and provide academic supply for sustainable use of wetland resource .In this paper the landscape pattern change of Dongting Lake wetland was studied. Dongting Lake wetland is one of the most important wetland ecosystems in China and it has complex and various functions and values.From 1980 to 2000,Dongting Lake wetland changed gradually due to natural factor and human activities.In order to better understand physical and human effect on wetland, protect and use the wetland resources sustainably in Dongting Lake area, it is necessary tor study the change of wetland landscape in Dongting Lake area .Some indices of the landscape pattern, such as landscape diversity index, landscape dominance index, landscape fractal dimension index are adopted .This study was on the basis of Chinese Academy of Sciences resource and environment spatial-temporal database and the two-stage remote sensing data: Landsat MSS data captured in 1980 and Landsat TM/ETM data captured in 2000. The result showed that wetland area increased by 16307hm2, of which paddy field and riverwetland decreased largely, but pond wetland area increased obviously.Totally artificial wetland area increased, while natural wetland decreased. Accordingly the landscape pattern indices changed with the changes of area and perimeter of several wetland types in Dongting Lake. These changes are the result of interactions between human activities and natural factor.But the human impact on wetland is the most important causation in the past two decades. The changes of wetland landscape made environmental quality and ecological function decade in Dongting Lake area, especially the flood disaster aggravate.