基于NDVI-ST双抛物线特征空间的冬小麦旱情遥感监测

Drought Remote Sensing for Winter Wheat Based on Double Parabola NDVI-ST Space

以河南省冬小麦旱情遥感监测为例,利用MODIS/AQUA卫星产品的归一化植被指数(NDVI)、增强型植被指数(EVI)、叶面积指数(LAI)和地表温度(ST)数据,分析了NDVI-ST和EVI-ST的特征空间,发现NDVI-ST和EVI-ST的特征空间具有双抛物线型特征。将其与三角形NDVI-ST、EVI-ST及LAI-ST特征空间进行对比分析,并将得到的温度植被干旱指数(TVDI)数据与土壤湿度进行相关性分析,揭示双抛物线型NDVI-ST特征空间能更好地反映地表10 cm土壤水分状况。以双抛物线型NDVI-ST特征空间得到的TVDI作为旱情遥感监测指标,评估了2011-02-26～2011-05-16河南省冬小麦旱情,并与当地气象站降雨数据对比,揭示了2011年春天河南省旱情发展的总体时空特点。

Take the drought remote sensing for winter wheat in He＇nan province as an example,the normalized difference vegetation index（NDVI）,enhanced vegetation index（EVI）,leaf area index（LAI） and land surface temperature（ST） data from MODIS/AQUA were applied to analyze NDVI-ST space and EVI-ST space.It was discovered that NDVI-ST and EVI-ST spaces were double parabola as compared with NDVI-ST,EVI-ST and LAI-ST triangle or trapezoidal space.The relationship between TVDI and soil moisture was analyzed with the obtained TVDI derived from the spaces.The results show that the NDVI-ST double parabola space is better than the others to reflect the 10 cm-depth soil moisture.Based on the TVDI obtained from the NDVI-ST double parabola space,the drought situation in He＇nan province,from February 26,2011 to May 16,2011 was evaluated.Compared with the raining data observed by local weather stations,the general spatio-temporal features of the drought situation of winter wheat in He＇nan in the spring of 2011 was revealed.