涑水河流域地形因子对植被指数变化的影响

植被覆盖及其变化是区域生态环境变化的重要信息，地形因子作为自然环境的重要因素是流域植被覆盖的重要影响因子，因此揭示流域地形因子对植被指数变化的影响，可为流域环境治理、科学管理、保护和可持续利用提供科学依据。选取山西省涑水河流域为研究对象，基于TM遥感影像和ASTER GDEM数据，提取了研究区植被指数以及海拔、坡度、坡向信息，研究涑水河流域植被指数随高程、坡度、坡向等地形因子的变化情况。结果表明：（1）低山区与平原区、丘陵区以及中高山区相比植被指数较低，是从农业植被向自然植被的过渡地带，重点工作是加强水土保持；（2）坡度为5°~10°区域，植被指数最低，该区人类活动频繁，主要是农作区，但作物长势较差，应加强土地的综合整治；（3）坡向对植被指数影响较明显，南坡植被指数最低，其次为东南坡和西南坡，北坡、西北坡、东北坡植被指数相对较高，反映出坡向对研究区植被覆盖的影响程度。

The Influence of Terrain Factors on Vegetation Index in Sushui River Basin

The change of vegetation coverage indicates the regional ecological environment and terrain factors as key factors of natural environment is important to basin’s vegetation coverage. Therefore, the influence of basin’s terrain factor on change of vegetation index provides scientific data for environmental and scientific management, protection and sustainable utilization. Based on TM remote sensing and ASTER GDEM, this paper presented the vegetation index varies with elevation, slope, aspect, terrain factors etc. in Shanxi Sushui River. The results showed that, low mountains with lower index than in plains, hills and high-middle mountains were transitional areas form agricultural vegetation to natural vegetation. Water and soil conservation was taken as priority. It was lowest index in slope areas 5°-10° which were mainly agricultural areas with frequent human activities and poor crops growing. Comprehensive improvement of land should be strengthened. The influence of aspect on vegetation index was significant and southern slope index was lowest, then southeast and southwest index. In northern, northwest and northeast slope, index was relatively high reflecting vegetation cover by aspect in studied field.