Abstract: With the aid of remote sensing and GIS technology,landscape patterns of various types of land use and their tempo-spatial distribution was studied through landscape pattern gradient analysis.Results show that during the years of 2002-2006,the overall landscape pattern of the city changed significantly,with urban land increased by 22.10%,while farm land decreased by 14.96%.Spatially,the present landscape features a gradient of urban area-rural-urban fringe-countryside,and temporally in time,the entire transect belt increased in patch density,but decreased in polymerization degree and the max patch index.At the type level,the gradient of urban landscape varied sharply;changes in water surface and roads were small,while changes in farmland,urban land and green land quite great in amplitude.The gradient analysis combined with landscape pattern indices can quite completely reflect characteristics of the changes in urban landscape pattern and structure.

Key words: landscape pattern gradient analysis, change in landscape pattern, land use type, Zhangjiagang