期刊名称:ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN:2194-9042
电子版ISSN:2194-9050
出版年度:2008
卷号:XXXVII-B8
页码:619-626
出版社:Copernicus Publications
摘要:The vegetation quality in upper catchment of the Yellow River is critical for ecological stability in the whole watershed, which is also sensitive to climate change. The dominant land covers in this region are grassland and forest, which intensively affect water quality and quantity, soil erosion for whole watershed. With MODIS products on twelve dates in 2000, 2003, 2006, the normalized difference vegetation index (NDVI) for grassland and forest was calculated with the reference data and the daily vegetation NDVI variation regression models in three years were deduced. Then, three watershed annual climatic indicators (i.e. yearly accumulated precipitation, highest and lowest temperature) were averaged from nine weather stations. After that, the inter-annual grassland and forest NDVI variation principles with three indices were regressed. Except the lowest temperature, the yearly precipitation and highest temperature had strong correlation with two community vegetations NDVI. The correlation coefficients of four regression models ranged from 0.8690 to 0.9768. Furthermore, the NDVI responses to monthly precipitation, highest temperature and lowest temperature were analyzed. The vegetation NDVI and three climatic indices had strong positive correlations and the coefficient was larger than 0.7331. The monthly correlation also provides the threshold value of three climatic indictors, which is the starting point for vegetation growth. Consequently, the daily weather information may be used to predict regional vegetation NDVI. Meteorological indictor may simulate the regional grassland and forest NDVI simulated with climate change considerations, which is critical for vegetation quality assessment and regional environmental management
关键词:Vegetation transformation; Correlation analysis; MODIS; Climatic variation; Yellow River