基于Landsat TM冬季影像的香格里拉高寒草甸分布的提取与验证

根据1995年地面实测的土地利用资料，识别香格里拉市不同坡度、坡向和海拔组合下的高寒草甸和裸地的分布情况，利用1995年Landsat TM冬季影像计算裸土植被指数和归一化植被指数，以识别潜在分布区内的裸地和绿色植被，进而分析1995年香格里拉市高寒草甸的空间分布格局。结果表明：1995年香格里拉市高寒草甸和裸地集中分布区的坡度为9°～37°，坡向为南、西南、西、西北和北方向，海拔为3900～4631 m；高寒草甸和裸地的潜在分布区为1742.89 km²。剔除潜在分布区内的裸地和绿色植被，提取得到1995年香格里拉市高寒草甸的面积为1070.28 km²，其中，在高寒草甸集中分布区域的提取面积为512 km²，与真实分布情况相比，其面积精度为76.10%，空间重合度为90.87%。因此，采用Landsat TM冬季遥感影像提取滇西北高寒草甸的分布（尤其在集中分布区）是可行的。

Extraction and Verification of the Distribution of Alpine Meadows in Shangri-La Based on Landsat TM Winter Images

The distribution area of the bare ground and alpine meadow was identified by the combinations of slope, aspect and elevation according to the materials that obtained by ground investigation in 1995. The bare soil vegetation index and were calculated to identify bare ground and forests using Landsat TM winter images in 1995. And then the spatial distribution of alpine meadow in Shangri-La in 1995 was obtained. The results showed that the slope of the concentrated distribution area of alpine meadow and bare ground is 9°–37°, the aspects are south, southwest, west, northwest and north, and the elevation is 3900–4631 m; the potential distribution area of the alpine meadow and bare ground in Shangri-La was 1742.89 km2 in 1995; the area of the alpine meadow extracted from Landsat TM winter images was 1070.28 km2 in Shangri-La. Especially, the extracted area of the alpine meadow in a major distribution region was 512 km2, where the area accuracy was 76.10% and the spatial consistency was 90.87% when comparing with the actual distribution. This study shows that it is feasible, especially in the major distribution area, to identify the distribution of alpine meadow using Landsat TM winter images in northwestern Yunnan Province.