洞庭湖区近20年土地利用/覆盖变化的时空特征

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

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。

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