Changes of Landscape Pattern in the Valley of Tabular Mountain and Hilly Areas in Western Chongqing Municipality

Landscape pattern in Zhangjia valley of the low tabular mountains and hills in Western Chongqing Municipality is studied by using five sets of land use data in 1957,1976,1982,1992 and 1998,quantitative methods of landscape ecology and techniques of RS GIS.Firstly,landscape is classified into six types of irrigable land,dry land,orchard,woodland,village and watershed,respectively,by using remote sensing images.Secondly,a geographical information system(GIS)is designed and set up based on digital data extracted from remote sensing images,field investigation data and other types of data,and then a digital map of landscape is figured out.Thirdly,depended on spatial analysis function of GIS,indexes for diversity,dominance,fragment,isolation and fractal dimension of each landscape type in different periods are calculated.It is found that with time elapsing and economical development,changes in the indexes become complicated and anomalistic.The rhythms of the changes are consistent with agricultural policies,increase in population and economical development.Fractal dimensions of landscape types from high to low are village,woodland,irrigable land,dry land,orchard and watershed in turn.Such a rank explicitly shows the complexity of landscape types.It is an effective method to study the processes,patterns and mechanisms of the changes in regional land use and land cover using landscape ecology and the techniques of GIS RS.