黄河三角洲植被指数与地形要素的多尺度分析  

MUTISCALE ANALYSIS OF VEGETATION INDEX AND TOPOGRAPHIC VARIABLES IN THE YELLOW RIVER DELTA OF CHINA

作　　者：吴大千[1] 刘建[2] 王炜[1] 丁文娟[1] 王仁卿[1,2] 

机构地区：[1]山东大学生命科学学院,济南250100 [2]山东大学环境研究院,济南250100

出　　处：《植物生态学报》2009年第2期237-245,共9页Chinese Journal of Plant Ecology

基　　金：山东省科技发展计划项目(2006GG2207002);山东省环保局科技项目(2006049);山东省优秀中青年科学家科研奖励基金(2006BS08008)

摘　　要：结合地理信息系统和遥感技术,研究了黄河三角洲植被指数NDVI与一系列地形要素间的尺度依赖关系,从而检验在较大尺度上滨海生态系统植被分布格局是否存在水分再分配的调控作用。结果表明:1)NDVI值在4种主要群落类型间差异显著,这种显著差异是由滨海盐生植物的生境特点决定的;2)地表高程在所有的10个粒度尺度上均与NDVI相关关系显著,这种显著关系在小尺度上与地下水埋深有关,而在大尺度上可能参与水分再分配过程;3)在750m粒度尺度附近存在水分再分配的调控作用,在该尺度附近地形湿润度指数(TWI)和坡度与NDVI相关达到极显著,而且其Moran's I指数突然增大。黄河三角洲的植被地形关系表现为不同尺度上对土壤水分和盐分的调控,在小尺度上地形因素通过土壤表面蒸发过程影响土壤水分与盐分,而在大尺度上地形因素主要通过地表径流对土壤水分与盐分进行再分配。Aims At larger scales, the elevational gradient interacts with the redistribution of water and soil solutes to determine regional vegetation pattern, especially in regions with small variation in elevation. However, little is known about the processes of water redistribution in coastal ecosystems. Our objective is to test if water redistribution affects vegetation pattern at large scales in a coastal eco- system in the Yellow River Delta using an integrated remote sensing and GIS method. Methods One-way ANOVA was employed to test whether normalized difference vegetation index （NDVI） is significantly different among four major plant communities. Correlations between NDVI and topographic indexes were identified by the Spearman non-parametrical method. Moran＇s I coefficients were also calculated for all selected variables. Important findings ND VI was highly different among the four communities, as determined by differences in habitat structure of coastal plants. Correlations between NDVI and elevation were highly significant at all scales, which may closely associate with the groundwater depth at smaller scales and with water redistribution at larger scales. At the 750 m grain scale, the correlation coefficients between topographic wetness index and slope were highly significant and the Moran＇s I coefficient increased abruptly, indicating water redistribution at this scale. Topographical factors affect the vegetation pattern via scale-dependent adjustment and control on soil moisture and salinity. At small scales, topographic factors regulate soil water and salinity through evaporation from the soil surface. At large scales, topographic factors redistribute the soil water and salinity through runoff and the groundwater system.

关 键 词：NDVI 多尺度分析 遥感 植被地形关系 黄河三角洲 

分 类 号：Q948[生物学—植物学]