四川盛夏伏旱的MODIS遥感监测方法

MODIS Remote Sensing Method of Midsummer Drought in Sichuan

本文利用2006～2010年7、8月的MODIS卫星遥感资料、土壤湿度观测资料和Ci综合气象干旱指数,讨论了NDVI-Ts特征空间干、湿边的拟合方法,建立了7～8月各旬的TVDI指数计算模型。根据31个农业气象站点的土壤相对湿度观测资料,获得了5种干旱等级的观测样本,并通过样本类内离散度、类间离散度,以及与土壤相对湿度和Ci指数相关性的比较,对比分析了TVDI和VSWI两种干旱遥感监测方法对四川盛夏伏旱的监测能力,结果表明:对于四川盛夏伏旱的遥感监测来说,用TVDI指数监测比用VSWI指数监测更合适,效果更好,TVDI指数监测到的干旱区比较可靠。

Utilizing the daily MODIS data,relative soil moisture data,composite meteorological drought index（Ci）in July and August from 2006 to 2010,it discussed the fitting method of dry edge and wet edge of NDVI-Ts feature space,set up the TVDI calculation models of each ten-day from July to August.According to the relative soil moisture data of 31 agricultural meteorological stations in Sichuan,it obtained the observed samples of five drought grade,through comparison of in-class scatter matrix,between-class scatter matrix,correlation with relative soil moisture and with Ci index of five kind simples,it analyzed the monitoring capacity of TVDI and VSWI methods to Sichuan midsummer drought.The result indicated： for the midsummer drought monitoring by remote sensing in Sichuan,using TVDI index monitoring was more appropriate and better effect than using VSWI index monitoring,TVDI index monitoring to arid area was more reliable.