The Monitoring Of Land Use Change In Eastern Part Of Qinghai Plateau Based On Remote Sensing

Land use change is the most significant aspect in the research field of globe environmental changing. The ecological environment frail zone can promptly and acutely influences global variation, so there is special significance that we study the ecological environment frail zone due to its peculiar trait. It is carried out eco-environmental protection and West Development which changes the ecology of the eastern agricultural regions of Qinghai plateau with complex topography and fragile ecologic environment. For the purpose of the benefits of reforesting formerly cultivated land and ecological/environmental control in eastern agricultural regions of Qinghai Plateau, automatically rapid extraction method of the complex of a wide range it was explored based on Landsat TM/ETM+data. Changing information of land use in this area was analyzed between1999to2009. This paper has given main fruits as follows:(1) This paper introduces a method of comprehensive remote sensing classification based on geographical division for a wide range of complex areas. For one thing, according to altitude, water and heat conditions, Land-use structure, Qinghai Plateau in eastern agricultural area with complex terrain is divided into the higher mountain region, the lower mountain region, the river valley region,which is a reference for a wide range of complex areas of remote sensing classification. For another, select the appropriate classification of each geographical district based on land class characteristics. The maximum likelihood classification is selected in the higher mountain region for its single, larger polygons after the sunny grass separated according to the gradient split; the lower mountain region with simple, uniform patches can be classified directly with the classical maximum likelihood classification; To improve the classification accuracy, constrained least square linear spectral mixture model is used in the river valley region,where have complex land types and many mixed pixels.(2) The results of land use change analysis show that:due to the implementation of western development, land for construction in nearly a decade is developed with a rapid speed which space change rate has been the forefront. New construction land comes mainly from areas with low altitude, low slope, convenient transportation, such as irrigated farmland, dry farmland, and unused land. Irrigated and dry farmland which mainly convert to grassland besides construction land show a decreasing trend.(3) The results of sloping farmland change analysis show that the farmland in the eastern agricultural regions of Qinghai plateau have made significant achievements. Elevation, slope, low grain yield with obvious ecological benefits sloping farmland is gradually restored to grassland and woodland.