黄土高原地区归一化植被指数时空动态变化及其与气候因子的关系

摘要

Based on SPOT NDVI and GIMMS NDVI data,combined RS and GIS techniques of geostatistical spatial analysis,the spatial and temporal differences of vegetation cover conditions in Loess Plateau area from 1998 to 2007 and the relationship between NDVI and main climatic factors（monthly average temperature,precipitation） were analyzed from 1991 to 2000.The results show that obvious regional difference of the NDVI value is displayed（the average value in July and August）,which presents the increasing tendency from north to south.The value in south,east and southwest are high,while in north and northeast they are low.Wave ascending trend is showed by NDVI value through the overall period from 1999 to 2007.And NDVI value is affected by different land-use types,the value in woodland was the maximum and it was the minimum in desert.The status of the low NDVI in Loess Plateau will be achieved by the optimization of land-use structure.The temperature and precipitation are the main climate factors determined the vegetation growth status in the Loess Plateau area,which have high positive correlation with NDVI value.%以SPOT NDVI及GIMMS NDVI为数据源,结合RS和GIS地统计空间分析技术,对1998—2007年黄土高原地区植被覆盖的时空差异及1991—2000年归一化植被指数（NDVI）与月均温、降水量的关系进行了研究.结果表明：NDVI值（7、8月平均值）在空间上表现出明显的区域差异性,NDVI指数由北向南递增,南部、东部及西南角部分的NDVI值较高,北部、西北部地区较低;1999—2007年整体呈波动上升态势,区域NDVI值的季节差异特征明显,夏季〉秋季〉春季〉冬季;土地利用类型影响NDVI值,林地的值最大,荒漠最小,土地利用结构的优化将改善黄土高原地区地表植被指数偏低的现状;气温、降水是决定黄土高原地区植被生长的主要气候因子,与NDVI指数呈现较高的正相关关系.