利用卫星遥感资料,对大渡河上游地区金川、壤塘、马尔康三县18665km²土地的景观格局与动态进行分析。结果显示,1995～2000年,研究地区的景观破碎化程度有所下降,多样性增加,斑块形状不规则性增强。整个景观表现出以草地为基质,以林地变动为主要特征。5年间,有林地面积减少53687hm²,大部分转变为灌木林地和疏林地。有林地的空间动态,如斑块密度下降,形状趋于规则等,显示该地区森林减少主要是有计划采伐的结果。耕地面积的下降则表明当地退耕还林、还草的政策措施已初见成效。

Based on satellite imagery,this paper has analyzed the landscape patterns and dynamics in the upper reaches of the Dadu River,which consists of3counties of Jinchuan,Rangtang and Maerkang,covering an area of18665km² .The results show a decreasing landscape fragmentation process,increased landscape diversity and irregularity of patch shape between1995and2000.The whole region is characterized by grassland being matrice and changes in forest land.Within5years between1995and2000,forested land decreased53687ha,most of which were converted to shrub and sparse woodland.The decreased density and increased regu larity of forest patches indicate that the decreased forests were due to a planned logging taken by local forestry enterprises.Meanwhile,a decreased cultivated land indicates that the governmental policy of“returning farmland to forest land and grassland”has taking effects.