摘要
植被覆盖面积的大小是反映区域性生态环境状况的重要指标之一,多年植被覆盖面积的变化则直观反映了植被生态环境随时间的变化规律。在前人研究成果的基础上,采用定量遥感技术,应用美国国家航天航空局最新的全球植被指数变化研究数据(GIMMS)作为数据源,对黑河流域1989-2002年间的植被面积变化规律进行了研究。考虑到实际的植被面积难以确定,因此采用等效面积法确定植被覆盖面积,通过统计遥感图像上植被指数(NDVI)值大于0.3的像素点值,以像素点值代表植被的面积,研究黑河流域14 a的天然植被面积变化规律。研究结果证明,黑河流域的天然植被在以每年约3%的速度减少。
Vegetated areas are important indices for regional eco-environment. The temporal variation of vegetation over a period of many years directly reflects the regulatory influence of vegetation on the ecological-environment. Based on previous-research and using quantitative remote sensing, this paper examines the variability of vegetated areas from 1989 to 2002 in the Heihe river basin, north-west China from GIMMS NDVI data. Owing to the difficulty in ascertaining vegetation area in this paper, we calculate the vegetation area using equivalent area method. The pixels with NDVI value larger than 0.3 in the image are counted and the number of pixels represents the vegetation area. Results indicate that the natural vegetation areas decrease at the annual rate of 3% in the Heihe river basin.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2005年第U04期166-169,共4页
Earth Science Frontiers
基金
国土资源部科技专项资助项目(200010302)
