近43年重庆主城区土地利用时空变化特征与预测

Changing is one special zone in west of China with a large area of three gorges reservoir zone.It has been developing rapidly since 1997,when it became a municipality directly under the central govement.With the process of urbanization, the land use has a huge change in this city area.In this study the main eight districts of changing were selected to investigate the spatial and temporal characteristics of the land use change in the recent 43 years is carried out by using RS and GIS,landuse change dynamic degree and human impact index model.The land use data is obtained from Landsat TM images in 1993,2000 and 2004,and the land use maps in 1961 and 1981.The results show that the urbanization process,as the most important economic growth pole in the main districts of Chongqing,plays an important factor in intensifying agricultural land transforming into urban construction land.Significant increase of urbanized land and decrease of paddy field and farmland are the image reflection.For the spatial variation,the land use type in central district of Chongqing has remained relatively stable in the recent 43 years,and the strength index of human impact has been on a high level of stable situation.While the effect of human activities increases obviously in Jiulongpo district,south district,Dadukou district,north bank district,south bank district and Shapingba district,and the regional strength index of human impact has risen to 65.75%, 53.58%,52.42%,58.27%,63.74% and 56.01% in 2004,which indicates the strong interference of human activities in the landscape of the urban and rural transition areas.The spatial and temporal patterns of land use in the next 30 years are forecasted by using Markov model.The results show that the area of urbanized land will account for 77.28% of the entire studied zone in 2030.And for the periodical features,the construction land will be up to 52.47% in 2010 from 24.27% in 2000,due to the rapid economic development and growing population,showing a linear dramatic expansion.The increase of urbanized land area will be relatively slow in 2010～2020 and 2020～2030 and the average annual increase rate in the 2 decades is 0.66%.It shows to some extent that the population in the major urban areas of Chongqing will reach the limit of capacity,and will transfer to external area(urban and rural transition area,rural area).