Feature Of Land Use Change And Analysis Of Its Changing Trend In Haihe River Basin

As the development of economy and society, growth of population and implementation of policy measures, the underlying surface in Haihe river basin change a lot. Land-use activity for certain purpose not only change some nature of land-cover, but also have a significant impact on the production, conversion and space-time configuration of water resources, which affected the runoff generating and flood process. So that we need analyze the changing feature and trend of different land use type in different periods, in order to prepare for studying on effects of land-use and land-cover change on flood in Haihe river basin, as well as provide some reference to land-use plan, management and ecological restoration in future. Daqinghe and Luanhe river basin are selected as the study areas in this paper, the main contents and results are as follows:(1) In the help of GIS technology, DEM and land-use remote sensing dates are used to extract the land-use condition of four typical watersheds in 1970, 1980 and 1990. On the whole, the land-use type is very various and exists obvious region difference, land-use of two typical watersheds in Daqinghe have large scale change between 1970 and 1980.(2)The comprehensive index of land use degree is used to study depth and breadth of land use in each watershed. Land use degree in some watersheds increases by comparison of different periods, but the other is in degradation. There is a gap between the degrees of land use in different areas through comparison of different watersheds.(3)Markov transition matrix model is used to describe the situation of transition between the various types of land use. The dominant and secondary causes driving certain type of land use to change are found throng analysis of the flow direction and source of a single land use type. The results show: The scale of land use transition of two typical watersheds in Luanhe is small during the study period, and almost all land-use types flow to and come from themselves mostly. There is large and multi-direction land use transition between 1970 and 1980 in two typical watersheds of Daqinghe. The area of medium coverage grassland flowing to high coverage grassland is largest, the proportion of wood land flowing to shrubbery land is biggest, the sources of various land use type are more abundant.(4)Three different models are used to compare and analyze the rate of change in order to study the dynamic changes of various types of land use and watershed as a whole. The results show: In reckoning the rate of change of a single land-use type, measurements resulting of different models are different, and for different land use type and the different study periods in different watersheds, the difference in size is also very different. The proposed spatial analysis model which considers the process of diverting and increasing can reasonably and precisely measure the dynamic change rate of land use.