洞庭湖区近20年土地利用/覆盖变化的时空特征

在中国资源与环境时空数据库的支持下,利用20世纪70年代末期、80年代末期和90年代末期获取的陆地资源卫星图像和GIS分析方法,对洞庭湖区近20年的土地利用/覆盖变化的时空特征进行了研究。结果表明,变化比较显著的地类有3种:耕地减少了1 97%,各类建设用地总计增加了14 88%,水域面积增加的幅度为8 77%。耕地与水域相互之间的转变比较频繁。以80年代末为界,前后2个10年间,建设用地、水域和草地的面积在2个时期均持续增加,耕地、林地的面积都持续减少。后期土地利用的动态度大于前期;前期动态度最大的县域有岳阳市、沅江县和汉寿县,后期动态度最大的则为石首市、津市和岳阳市,全部为市级行政区或县改市区。

Spatial-temporal Changes of the Land Use/Cover in the Dongting-Lake Area during the Last Twenty Years

The research on the land use/cover change is one of the frontiers and hot spots in the globe change research Based on the Chinese resource and environment spatial temporal database, and the Landsat TM?MSS and ETM data which were acquired at the end of 1970’s?1980’s and 1990’s respectively, we analyzed the spatial temporal characteristics of land use/cover changes in the Dong ting Lake area The result shows that during the last twenty years there were three land use types that have changed remarkably The cultivated land decreased by 1 97% of total cultivated land The construction land and water area expanded, with an increase of 14 88% and 8 77% respectively The land use change speed of land use type at the period between the end of 1970’s and 1980’s is slower than that at the period between the end of 1980’s and 1990’s Three cities and towns, Yue yang City?Yuan jiang County and Han shou County have gotten the greatest value of the degree of land use change in all administrative district at the previous 10 years, which means that the land use in these cities and towns has changed much quickly However, at the later 10 years, Shi shou City and Jin shi City, all of them are city level district,have developed from county to city, replacing Yuan-jiang County and Han shou County, and have gotten the greatest value of the degree of land use change.