中国华东及其周边地区NDVI对气温和降水的月际响应特征

Inter-monthly Response Characteristics of NDVI to the Variation of Temperature and Precipitation in East China and Its Surrounding Areas

利用SPOT VGT-NDVI数据和气象站点的气温和降水资料,分析了1998—2010年期间我国华东及其周边地区NDVI对气温和降水变化的时空响应特征。结果表明,在整个研究区,NDVI对当月气温和前1月降水变化响应最为强烈。空间上,NDVI对气温变化的响应在整个研究区差异不明显,而对降水变化的响应在北部地区较在中部和南部强。NDVI在多数地区都同步响应于当月气温变化,在北部和南部一些地区对气温变化滞后响应1个月左右。NDVI对降水变化在北部地区滞后响应1个月左右,而在南部地区滞后响应2～3个月。研究区NDVI对气温和降水响应的时间特征、空间分布及总体滞后期与已有的研究结果基本一致,但在南部地区NDVI对降水变化的响应滞后期较已有的研究结果长。不同的数据源、研究范围、气候和植被类型及土壤特性的差异等都有可能造成研究结果的差异。

The interaction between vegetation and atmosphere is important in global climate change and natural resource management and has become a research focus of geosciences in recent years.Spatial and temporal response characteristics of NDVI to the variations of temperature and precipitation in East China and its surrounding areas were analyzed based on the SPOT VGT-DN data from Flemish Institute for Technological Research（VITO）,Belgium,and monthly temperature and precipitation data from 135 meteorological stations during 1998-2010.The results indicate that in the whole study area,NDVI has the maximum response to the temperature of the same month,and has the maximum response to the precipitation of previous one month.Spatially,the response of NDVI to temperature has no significant difference among the whole study area,and the response of NDVI to precipitation in the northern part is stronger than that in the middle and southern part of the study area.In the middle part of the study area,NDVI synchronously responds to the variation of temperature in the current month,but in the northern and southern part,it responds to the variation of temperature with a lag of about one month.In the northern part of the study area,NDVI generally responds to the variation of precipitation with a lag of about one month,but in the southern part,it responds to the variation of precipitation with a lag of 2 or 3 months.The temporal response characteristics,spatial distribution and the general lag time of the NDVI to temperature and precipitation in East China and its surrounding areas are consistent with other results,but in the southern part,the lag time of NDVI to the variation precipitation is longer than other results.The difference of data source,study area,climate and vegetation type,and soil property may result in the difference between our and other results.