The Change Analysis Of Land Use And Landscape Patterns In Shiyang River Watershed

Land use and Land cover is one of the important fields of global environmental study change. The study at hands addresses the issue of land use change in Shiyang river drainage area, which the ecological environment deteriorated because of excessive human productive activity. Therefore many problems have appeared such as desertification, forest degradation, and soil salinization and so on. At the same time, great changes of land use have taken place in study area. This thesis contributes to the detection of land use change providing a land cover classification derived from LANDSAT TM5 imagery acquired in 1994 and 2005 respectively, in addition ancillary data with the help of GIS technology, mathematics model and landscape-ecology theory. Based on the classified data, some analyses are done such as land use structure change, land use rate, land use degree, land use transition and so forth. The conclusions are attained as following:1 Between 1994 and 2005, the farmland, woodland, urban and built-up, unused land area have all increased; however, grassland and water bodies have decreased. The results indicate that the influence of human activity is enhancing constantly.2 Land use degree is higher and show the features of regional disparity in the study area. Most regions are at the developmental age in general, Minqin has the lowest composite index of land use degree.3 Relative change rate of different land use type in the study area is obvious different, however, spatial pattern is not permanent.4 The spatial centroid of each land use type has changed with different extent. In such changes, drift distance of grassland reach to 19.837km, which the distance is the biggest; however, the spatial centroid of other type is indistinct.5 Patch density, numbers of patches are decreased and largest patch index is increased. Such changes demonstrate that the landscape fragmentation level is reducing. At landscape level, the landscape Diversity Index and Evenness Index are decreased, which show the influence of human activity at extent.6 Social, economic, technology and policy all are important factors of influencing the land use change in Shiyang river drainage area. However, increasing population is the key driving force in LUCC of Shiyang river drainage area.