Abstract:

Using GIS,the indexes of diversity,evenness,fragment,abruption and fractal dimension have been chosen to analyze the landscape pattern changes and their influencing factors in Yidong Town,Hanyuan County which are located in the upper reaches of the Liusha River with reference to the land use map in 1985 and 1994 and the remote sensing images in 2003.The research shows a growth in the indexes of diversity,evenness,fragment and abruption of the whole landscape; the regulating effect of woodland has been continuously decreasing,which made the shape of landscape turned out to be comparatively complicated. The analysis of the influencing factors shows that the influence of towns and roads caused the surrounding landscape to be manmade dry land in the majority. Among the topographical factors,the habitation area and paddy fields are largely distributed at hill areas lower than 15°,at plain and at northfaced slope while woodland,bushes and grassland are comparatively more occurred at hill areas higher than 15°. The distribution of woodland at northfaced slope is a little more than that of other aspects; the distribution of bushes at southfaced slope is more than those of northfaced slope; and the distribution of dry land reaches its peak at halfsouthfaced slope.

Key words: RS and GIS, landscape pattern changes, landscape metrics, influencing factors