影像分辨率对植被覆盖度提取的影响

研究植被指数以及植被覆盖度演算结果与影像分辨率的关系可以为遥感影像在大、中尺度下的合理利用提供理论依据。以陕西省安塞县的县南沟以及纸坊沟的部分区域作为研究区，对SPOT、MODIS、TM、ALOS、IKONOS五种基本分辨率的影像进行了NDVI的计算并利用像元二分模型反演出植被覆盖度，在此基础上进行了统计分析和空间结构分析，实验结果表明30 m分辨率的TM影像无论是在统计结果还是在精度分析中均适用于小流域范围，而500 m分辨率的MODIS以及1 000 m分辨率的SPOT数据可以在研究区扩大至10 000 km²条件下使用。

Scale Effect Analysis of the Extraction about Vegetation Coverage

Research on the relationship between vegetation index, vegetation coverage calculation results and the image resolution can provide theory basis for the rational use of remote sensing image under the large-scale and middle scale. This paper selects Xiannangou and Zhifanggou watersheds of Shaanxi Province as the study regions.The five basic resolution images of SPOT, MODIS, TM, ALOS, IKONOS were used to calculate the NDVI and vegetation coverage. And then the analysis on statistical characteristics and spatial structure was performed. The results show that TM images (30 m resolution) is applied to small watershed in terms of both statistical results and the accuracy analysis. The MODIS (500 m resolution) and the SPOT (1 000 m resolution) can be used for the study area with up to 10 000 m².