半干旱环境下的土地利用/覆被时空变化研究-以吉林省通榆县为例

通榆县作为松嫩沙地的重要组成部分，是半干旱环境下典型的土地生态环境脆弱区。以1979年、1992年和2001年3期Landsat影像为数据源，在RS、GIS技术和景观生态学理论的支持下，全面分析了通榆县22 a来土地利用/覆被类型的时序和空间景观变化特征。结果表明：研究区土地利用/覆被类型以耕地、草地、林地和重度盐碱地为主，并且在时序上呈现出草地迅速减少、重度盐碱地大面积增加的趋势；在空间景观上呈现出耕地、草地、林地高度破碎与重度盐碱地高度集聚的特征。土地利用程度指数还表明研究区土地正处于由衰退期向发展期过渡的转型阶段。
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Spatio-temporal Change of Land Use/Cover in Semi-arid Region: A Case Study of Tongyu County, Jiling Province

Tongyu county,an important part of Songnen desert,is the typically frail zone of land eco-environment in semi-arid region.The objective of this study is to analyze the temporal characteristic and spatial landscape characteristic of land use/cover of Tongyu county from 1979 to 2001.Firstly,various land use types were derived from multi-temporal landsat images(MSS,TM,ETM ) from 1979 to 2001.Then the area and the landscape characteristic of various land use types were calculated by using GIS and land metrics.The results revealed that:(1) the dominant land use types in Tongyu were cultivated land,grass land,forest and severely Saline-alkali land.(2)The primarily dynamic change of land uses in Tongyu were the decreasing grassland and the increasing severely Saline-alkali land.(3)The fragmention of cultivated land,grass land and forest increased instantly while it is opposite to the severely saline-alkali land.(4)Tongyu county is in the transition phase from wane to stabilization.