甘肃祁连山哈溪林区植被覆盖度变化监测研究

Vegetation Coverage Monitoring in Gansu Qilian Haxi Forest Region

以甘肃祁连山哈溪保护站为主要研究区,选择1995年、2011年Landsat TM全波段遥感影像数据,以保护站1∶5万数字地形图及矢量化的林相图作为基本信息源,对遥感数据进行辐射定标、大气校正、图像裁剪处理,计算出2期影像的归一化植被指数(NDVI),采用像元二分模型对植被覆盖度进行估算。结果表明,祁连山哈溪林区植被覆盖度整体上呈增长趋势,植被覆盖度60%以上的高植被覆盖区域面积明显增加,植被覆盖度60%以下的低植被覆盖或无植被覆盖区域面积明显减少,研究区植被覆盖度呈逐步增长的趋势。

Taking Haxi Protection Station, Qilian Mountain, Gansu Province as study area, and selecting 1：50 000 digital topographic map and vector forest map of LANDSAT TM full-band remote sensing data of 1995 and 2011 as basic information source, the vegetation index （NDVI） of two stage images have been calculated on the base of radiometric calibration, atmospheric correction and image trimming. Thus, vegetation coverage was estimated by using pixel two-division model. The results showed an increasing trend of vegetation coverage in Qilian Mountain was apparent, the area of vegetation coverage more than 60% was increasing significantly, the vegetation coverage lower than 60% or non-coverage was reducing significantly. Vegetation coverage in the study area showed a gradual growth trend.