最近10年鄱阳湖区土地利用格局的时空变化

SPATIO-TEMPORAL CHANGES IN PATTERNS OF LAND USE IN POYANG LAKE DURING THE LAST DECADE

利用 198 8和 1998年 4月份的TM遥感数据 ,采用最大似然法对鄱阳湖区的土地利用进行机助分类。把研究区土地利用分成 7种类型 :林地、灌草坡、水体、湖滩洲地、耕地、城镇用地和裸地。采用空间叠加的方法得到研究区土地利用的转移矩阵。结果显示 ,林地、水体、城镇的面积增加 ,灌草坡的面积减少。 1998年耕地面积比 1988年面积减少 11.3% ,湖滩洲地面积减少 42 .7%。对不同高程的土地利用变化分析表明 ,耕地、灌草坡的面积都有所减少 ;城镇的面积增加 ,林地的面积增加明显 ,尤其在丘陵山区。土地利用的变化受到自然和人文因子的双重影响。水体面积增加的主要因子是降水量的增大 ;林地、灌草坡的变化明显受到政策等因素的影响 。

Changes in land use in Poyang Lake from 1988 to 1998 had been explored based on the maximum-likelihood method, using remotely sensed data from Thermatic Mapper (TM) in April 1988 and April 1998. The land use was classified into seven types, forest, shrub-land, meadow, water-body, crop-land, urban-land and bareland.The matrix for land use change was obtained by using 'overlaying'. Areas of forest, water-body and urban-land types increased, while those for cropland, meadow and shrub-land types decreased during the past decade, with a decline of 11.3% for the crop-lands and 42.7% for the meadows. At all elevations the area of both croplands and shrub-lands decreased, but that of urban-lands increased. The area of forests increased markedly and it is especially at the elevation of over 100 m. Results from an analysis on factors affecting the changes in area of land-use types indicated that precipitation controlled the area of water-body and meadow, and the policy-related factors restricted conversions of forests and shrub-lands.