基于MODIS-EVI区域植被季节变化与气象因子的关系

以浙江省为研究区域，利用2001—2004年MODIS-EVI和52个气象站点的日平均气温和日降水量，结合区域土地利用现状数据，采用时滞互相关分析方法，分析耕地、林地、园地增强型植被指数(EVI)季节变化与气温、降水的相关性.结果表明:浙江省大部分地区EVI对气温的最大响应没有时滞性，而对降水最大响应时滞为1个月左右.气温、降水对大部分地区植被生长季节变化有显著影响的时效均约为50 d.不同滞后时间，3种用地类型植被EVI与气温、降水的相关系数大小不同，在零时滞时，林地最大，园地次之，耕地最小；在非零时滞时，耕地最大，园地次之，林地最小.3种用地类型植被EVI与气温的相关系数均大于降水，说明气温对植被EVI季节变化的影响比降水明显.

Correlation analysis of regional vegetation seasonal fluctuation and climate factors based on MODIS-EVI.

Taking Zhejiang Province as study area, and based on the data of MODIS-EVI, daily mean air temperature and daily precipitation from 52 weather stations, and actual land use in 2001-2004, the time lag cross-correlation analysis was made to relate the seasonal fluctuations of enhanced vegetation index (EVI) of farmland, woodland and garden plot with air temperature and precipitation. The results indicated that in most areas of Zhejiang, EVI had no time lag to air temperature, but about one month lag to precipitation. The time that air temperature or precipitation significantly influenced the seasonal fluctuation of most areas EVI lasted about 50 days. The correlation coefficients of the EVI of farmland, woodland and garden plot with air temperature and precipitation differed with time lags. When the time lag was zero, the correlation coefficient decreased in the sequence of woodland > garden plot > farmland, and when the time lag was not zero, it changed in adverse. The EVI of these three land-use types all had stronger correlation with air temperature than with precipitation, indicating that air temperature had more influence on the seasonal fluctuation of EVI.