新疆2000-2012年NDVI、降水和RUE的时空特征

本研究分析了新疆2000-2012年每年的6-9月归一化植被指数(NDVI)、降水量和植被降水利用率(RUE)空间分布特征和年际变化趋势。结果显示,1)月平均降水量和月平均NDVI空间分布均呈西北向东南递减的特征,13年间年降水量和年NDVI均呈现北疆递减、南疆递增的特征,但年降水量年际变化范围更明显;2)月平均降水量和月平均RUE空间分布对比不明显,年RUE与年降水量的年际变化呈相反趋势;3)不同土地类型中降水量和NDVI呈显著正相关(r>0.3,P<0.05),降水条件对植被空间分布影响明显,不同土地类型中降水和RUE呈显著负相关(r<-0.22, P<0.05),夏季过量降水对植被光合作用的抑制作用是其主要影响因素。

The spatiotemporal characteristics of NDVI,precipitation and RUE during 2000-2012 in Xinjiang

In the present study, the spatial distribution characteristics and the interannual variation of NDVI, precipitation and RUE from June to September during 2000-2012 in Xinjiang were analyzed. The results showed that the spatial distribution characteristics of monthly mean precipitation and monthly mean NDVI decreased from northwest to southeast, and the annual precipitation and annual NDVI increased in north Xinjiang, decreased in south Xinjiang although the annual precipitation changed more obvious. The spatial distribution comparison characteristics of monthly mean precipitation and monthly mean RUE was not obvious and the variation of annual precipitation and annual RUE was opposite. In different land use types, there was significantly positive correlation between precipitation and NDVI (r>0.3, P<0.05) which showed that precipitation conditions had significant influence on the vegetation spatial distribution. There was significantly negative correlation between precipitation and RUE(r<-0.22, P<0.05), which showed the inhibition effect of excessive precipitation on vegetation photosynthesis.