摘要
根据2004年9月13日至14日在西藏高原中部地面观测的植被覆盖度和同期接收的EOS/MODIS数据,分别建立了250m分辨率归一化植被指数(NDVI)、土壤调节植被指数(SAVI)与地面观测的植被覆盖度之间的相关关系,并以西藏高原中部和整个西藏高原作为两个试验区,选择典型植被类型,验证了Carlson和Ripley植被覆盖度算法的精度。结果表明,地面观测的植被覆盖度与植被指数之间呈线性关系。其中,地面观测值与NDVI的相关系数R2=0.90;与SAVI的相关系数为R2=0.89;Carlson和Ripley算法适合于中等植被覆盖度的草地植被。
The relationships between NDVI and SAVI from MODIS（Terra）imagery on September 13and 14,2004,and vegetation coverage derived from field measurements investigated at same time with MODIS data in central Tibetan Plateau are analyzed.Another hand,after selected typical grassland vegetation re-gion in central Tibetan Plateau and whole Tibetan Plateau as two study areas,the accuracy of Carlson and Ripley algorithm of vegetation coverage is validated using field measurements in this paper.The main con-clusions are as follows.（1）The relationship coefficient between NDVI and vegetation coverage from field investigation is 0.95（R2=0.90）,between SAVI and vegetation coverage reaches 0.94（R2=0.89）.（2）There is high relationship between vegetation coverage based on the field measurements and esti-mation from Carlson and Ripley algorithm,coefficients are greater than 0.94;it was found that Carlson and Ripley algorithm is suitable for the middle grassland vegetation coverage.（3）Overall,the vegetation coverage over Tibetan Plateau is low;the area of vegetation coverage lower than 20%covered more than 50%of total area.The vegetation coverage between 1%～10%is the largest area（35.36%）and it mainly distributed over northwestern area and south of Mountain Kunlun in Tibetan Plateau.The area of 100%of vegetation coverage is 122 538.88km2 and it covered 10.72%of the total are-a,which distributed in southeastern Tibetan Plateau where dominated by forest vegetation.The distribu-tion pattern of vegetation coverage over Tibetan Plateau decreases from southeast to northwest in Tibetan Plateau.
出处
《遥感技术与应用》
CSCD
北大核心
2010年第5期707-713,共7页
Remote Sensing Technology and Application
基金
国家自然基金项目(40361001)资助
