【摘要】 运用线性光谱混合模型并引入植被景观指数解析乌鲁木齐市绿色空间格局及变化特征,为定量评价干旱区绿洲生态环境提供更精确的方法.结果表明:(1)植被盖度与植被指数整体相关性较好,但植被盖度更能反映像元尺度上植被信息较弱的城市植被景观;(2)13年内,植被丰度整体下降明显,存在郊区绿地面积锐减、建成区绿地破碎化程度加剧及空间分布不协调等发展问题;(3)从建成区植被类型看,中、高丰度植被面积缩减最大,低丰度植被面积变化不大但其破碎化程度最大,以低丰度植被占主导的城市绿地结构单一化趋势明显,城市绿色生态系统较不稳定.更多还原

【Abstract】 The pattern of urban green spaces and its variation characteristic in Urumqi were analyzed under a linear spectral mixture model as well as vegetation landscape index,to provide a more accurate method in quantitative evaluation for ecological environment of oasis cities in arid areas.The results indicate that,(1) In terms of the region as a whole,the relevance of vegetation fraction and vegetation index is closer,but vegetation fraction is better able to reflect urban vegetation landscape with weak vegetation information at pixel scale.(2) In the past 13 years,the vegetation abundance has declined obviously overall in the study area and the serious problems of urban ecological development in Urumqi are remarkable,just like green coverage falling sharply in outskirts,greenbelt fragmentation intensifying in built-up area,spatial distribution of greenbelt being incompatible and others.(3) Viewed from vegetation types in built-up area,the vegetation with medium and high abundance has shrunk largest in area and the area of low abundance vegetation hasn’t changed much,but the fragmentation of low abundance vegetation is most serious.Moreover,the structure of urban greenbelt based on the principle of low abundance vegetation trends single obviously,which will result in instability in urban green ecosystems.更多还原