Abstract:

Along with the intensive study of the relation between landscape pattern,ecological process and function,spatially optimizing the landscape pattern is coming to be one of the frontier issues in the area of landscape ecology.Unfortunately,there are yet not well established schemes,because different regions often lead to various optimal criterion and various schemes.In this research,we placed our eyes on the Zagunao watershed in the upper Minjiang River,Sichuan Province.The environment in the zagunao watershed was vastly changed and damaged while the cover of forests decreased,arid river valley expanded and increased cultivation area in ecologically fragile region.The influence of the fragmented landscape lies in that biodiversity and soil fertility decreased,the amount of soil erosion rose,and so on.This paper is trying to find a new method to optimize the landscape pattern for a special criterion.In the research presented in this paper,we built the spatial databases of Zagunao watershed with the support of geographic information system (GIS) and remote sensing (RS) technology.The datasets included landscape map（1974 and 2000）,monthly average temperature and precipitation for ages,(DEM)digital evaluation map and soil map.For the aim of relieving the seriously focused ecological problem of soil erosion and optimizing the landscape in spatial pattern,the potential soil erosion was calculated with pRUSLE (the potential relative universal soil loss equation) firstly,assumed that the watershed is not covered by any kind vegetation which represent the worst ecological condition.We combined the means of spatial modeling and landscape priority definition with regard of the potential soil erosion and vegetation distribution regularities in the calculating environment of GIS.By comparing the difference between the optimized landscape and the landscape in 1974,2000 respectively,the spatially optimized landscape might obviously lead to less soil erosion than that of 2000.In addition,this work presented new method for the likely research both in the area of theory and practice