Study On Land Use Change In Jingbian County Based On DEM

Terrain factors are closely linked the land use pattern. Land use pattern of differentterrain features not only reflect the human disturbance degree and land use change results,but also direct response natural economic conditions and social interaction performance.Jingbian is located in the transition zone of the loess plateau and Maowusu desert. The landtype of research area is rich because of complex terrain characteristics and influenced by thenational policy of returning farmland to forest and grassland and21st century energy base inrecent years. Through the analysis the land use change can reflect the different landformregion of regional land use change response process of policy for the reasonable use of theregional land to provide a theoretical basis.The data used in this research include DEM data and TM remote sensing images datawith30m resolution. Using remote sensing and GIS techniques obtained terrain factors ofstudy area such as topography, surface roughness, elevation, slope and terrain gradient.Decision tree classification method was used to get four land use maps form TM sensingimages in1995,2000,2005and2010. The relations between terrain factors and land coverchange were analyzed by GIS spatial analysis function. The conclusions as follows:(1)In study period, the number of farmland, grassland and water area is in an downwardtrend，forest land and the construction land is in an increasing trend. By2010, forest land andgrassland are the main land use type in the study area.(2)In the study area, the main landscape area is tiny rolling grass land area and the highfluctuation hilly-gully region, Main elevation area is form1300meters to1600meters, themain slope is the ground flat. In terms of the landscape, the regions of which are smallclassification in terrain factors classification decreased patch density. Diversity index in theseareas increased and fragmentation degree decreased.(3)Contrast the change of the terrain gradient in study area in different land types foundvarious land types in topography on the distribution pattern of performance for high, mediumand low spatial distribution structure. (4)The main risk degree reduced from the three to two in study area. that of returningfarmland to forest (grass) project achieved remarkable results, the study area of vegetationcoverage increased, and significantly improved the ecological environment.