| Cause the climate in Loess Plateau typically drought whit little rain and more evaporation, there is severe erosion problem there. Large quantities of soil and water loss, and other serious ecological problems plagued the social and economic sustainable development. At the same time, due to human and natural factors of land use pattern change,the vegetation landscape changes have direct and indirect impact on the soil and water loss, discover the interrelation between erosion and vegetation landscape change will help us to found ways for further erosion control and local economic, environmental development plans.In this paper, according the theory and methods of landscape ecology,to study the landscape structure and change in the Qingshuihe watershed of Shanxi Province, in the support of the RS and GIS technology, with the help of RS tool of PCI based on the information from Landsat-TM image,firstly, GIS and a landscape structure analysis program, FRAGSTATS are combined to compile a few landscape maps based on Landsat-TM images of the watershed from1986 to 2007.Combined with field survey information and a topographic contour map were used for landscape mapping of the Qingshuihe watershed.By using layer overlay analysis the distribution variation of different landscape types is studied and its causes in this watershed.And a series statistic data of rainfall, runoff and sediment loads in this watershed from 1986 to 2005 were also processed by grammatical analysis to show the interactive relationship between the dynamic change of landscape and the gradually change of the rainfall, runoff and sediment loads.The results show:the vegetation landscape matrix is always grassland and shrubs, grassland landscape elements is the absolute superiority in 1986, accounted for 41.69% of the total area of landscape, and the sectors-connecting is better, the bush area accounting for 21% of the total area, but accounting for 42% of the total number of plaques,that means more scattered and broken.In 1986 the vegetation landscape elements of sort for size is: Grass> deciduous > shrub> crop >coniferous >orchard > residential land, the three categories grass, shrubs and deciduous forest account for 87% of the total area of the above.With the annual increase, watershed landscape changes for the year 2000 watershed vegetation landscape elements of sort for size: grass>shrub>deciduous>crop>coniferous>orchard > residential land.In 2007 watershed vegetation landscape elements of sort for size: shrub> deciduous>grass> coniferous >crop>orchard > residential land, the area shrubs plaque become the first place, covering 15,571 hm2, accounting for 35.97 % of the total area, and was the absolute superiority watershed landscape. At the same time, the volume of sediment sort for amout from big to small: 1986>2000>2005years, from 1986 to 2005, decreasing the volume of sediment, respectively, with the vegetation landscape changes corresponding to the three sessions contrast, landscape area of grassland decreased year by year, the 1986 grass landscape of the valley landscape proportion of the total area of 41.69%, 2007 decreased to 25.41% , proportion of the plaque of shrubs area continued to increase, from 21% in 1986 to 36% in 2007. With less grass area, shrub area increasing, decrease sediment basin, for the reason that the grassland ecological system is of simple structure, and also indicated that this type of landscape can not effectively control the runoff and sediment, and shrubs can have some effect in controling the sediment and weaken the soil erosion. With the gradually change from grass to shrub, volume of sediment was also deceased year by year,so the measure of increasing shrub coverage rate on barren hill can be take to weaken the erosion and conserve the soil and water in this watershed.
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