Remote-sensing based winter wheat growth dynamic changes and the spatial-temporal relationship with meteorological factor

Based on MODIS-NDVI data, taking Shaaxi and Gansu provinces as examples, this paper explored the correlation between different grades of winter wheat growth and main meteorological factors at 7 different phenophases. The growth condition of winter wheat from sowing to maturity stages from 2011-2012 were assessed based on MODIS-NDVI data, then, the lag correlation between different grades of winter wheat growth in each phenophase and the meteorological factors with corresponding phenophases (temperature, precipitation) were analyzed by using correlation analysis, and GIS spatial analysis methods. The results showed that the winter wheat growth varied across time and space in the study area. And no matter what grades of winter wheat growth, the correlation coefficients between winter wheat growth condition and accumulated precipitation were higher than synchronous precipitation and pre-phenophase precipitation in terms of the average value in 7 phenophases. The influences of temperature on winter wheat were different according to different grades of winter wheat growth. The study showed that winter wheat with better growth condition was more sensitive to precipitation; whereas winter wheat with normal growth condition was largely influenced by temperature in the whole. This study is of significant to comprehend the quantitative relationship between meteorological factors and crop growth.