Landscape Pattern Optimization Based on RS and GIS in Northwest of Beijing

Heterogeneity of landscapes is supposed to be of significant importance for biodiversity and ecological function in urban ecosystems.However,land use activities caused primarily by urbanization process has a profound and far-reaching impact on stability of landscape and differences of landscape structure at the regional scale.Therefore,in this paper,the northwest region of Beijing is chosen as a study area and the technologies of remote sensing(RS)and geographical information system(GIS)is applied,and meanwhile the priority is been given to understanding of the spatial-temporal characteristics of landscape pattern change through visually interpreting Landsat TM images of 1989,1996 and 2005 respectively.It is believed that there are a series of landscape ecological problems because of city expansion,such as low landscape ecological connectivity,simplified landscape structure and more obvious fragmentation of green land patch in the plain areas.Moreover,spatial distribution of green land is unbalanced.In order to solve those problems,according to the principle that the movements of flow,energy and material in a landscape are related to some factors such as distance,time,impedance,etc.,this study adopts an accumulative cost distance model,combines with ecosystem services and spatial interactions of landscape types,analyzes the spatial difference of the ecological function and the compactness of landscape structure in the study area,and further discusses the landscape pattern optimization proposal.