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以2000年和2005年ETM+影像为数据源,在水体掩膜和端元光谱优选对比基础上,利用线性光谱模型提取了广州市植被覆盖信息,并对植被覆盖信息的时空动态变化进行了定量分析,结果表明:应用线性光谱模型之前对所占面积不大的水体进行处理是非常必要的,选取植被、硬化地面、土壤三端元法比包含阴影的四端元法更有利于线性光谱分离,而且能达到很高的精度;此外,通过对植被覆盖信息空间结构和景观格局的研究,显示:2000-2005虽然广州市绿化取得了初步成效,但总体植被覆盖状况呈下滑趋势,植被景观破碎程度增加,各植被景观形状趋于复杂化,城市化的发展加之人类活动的干扰,低植被覆盖区不断扩大,而中、高植被覆盖区正处于不断退化时期。
Taking the ETM + images of 2000 and 2005 as data sources, the spectral information of vegetation cover in Guangzhou was extracted by linear spectral model based on the optimal contrast between water mask and endmember spectra, and the temporal and spatial dynamic changes of vegetation cover information were quantitatively analyzed The results show that it is necessary to deal with a small area of water body before the application of linear spectral model. The selection of vegetation, hardened ground and soil triad method is more conducive to the linear spectral separation than the shaded four- In addition, through the study on spatial structure and landscape pattern of vegetation cover information, it shows that although the greening in Guangzhou has achieved initial success, the overall vegetation cover is in a downward trend and the degree of vegetation landscape fragmentation Increasing the landscape shape of vegetation tends to be more complex. The development of urbanization combined with the interference of human activities, the area covered by low vegetation is continuously expanding while the area covered by medium and high vegetation is in a period of continuous degradation.