宁夏不同植被类型归一化指数与气象因子分析

Correlation between NDVI and meteorological factors of different vegetation types in Ningxia

针对植被动态对气候变化响应的问题,提出了从小尺度范围研究植被指数与气象因子的相关性,采用2000—2010年MODIS归一化植被指数数据集和宁夏10个气象站2000—2010年逐月气象资料,分析了气象站点周围10km缓冲区内不同植被类型NDVI与气象因子的相关性。结果表明:2000—2010年宁夏不同植被类型NDVI均呈上升趋势;极端最低气温、最高气温、平均气温、平均相对湿度以及日照时数对宁夏地区植被的生长有明显的滞后效应;植被NDVI与极端最低气温的相关性系数最大,其次是平均气温;不同植被类型的NDVI与极端最高气温、极端最低气温以及平均气温的相关性由南向北呈现波动性增长,与降水量的相关性由南向北呈现明显的减小趋势;且耕地NDVI与各气象因子的相关性最大。

Aiming at the problem of the response of vegetation dynamics to climate change, this paper studied the correlation of vegetation index and meteorological factors from small scale. Taking the MODIS normalized difference vegetation index （NDVI） data sets and monthly meteorological data from 2000 to 2010 in Ningxia as test data, the correlation between NDVI of different vegetation located 10 km butter from the meteorological station and climatic factors was analyzed. The results as follows： NDVI of differ- ent vegetation in Ningxia remains on a growth trend from 2000 to 2010; the extreme minimum tempera- ture, maximum temperature, average temperature, average relative humidity and sunshine hours have obvious lag effect on vegetation growth in Ningxia; the correlation coefficient between NDVI and the ex- treme minimum temperature is the largest, followed by the average temperature~ the correlation of NDVI and the extreme maximum temperature, the extreme minimum temperature and average temperature presents volatility increase from south to north; the correlation of NDVI and precipitation presents obvious decrease from south to north; in addition, the correlation between NDVI of cultivated land and meteorological factors is the biggest.