【摘要】 植被作为干旱的承载体,其含水量的变化反映了旱情的时空分布以及受旱程度。文章从监测原理、植被水分表征以及遥感数据反演模型等三个方面,开展了基于多光谱遥感数据的植被水分反演方法研究。以2010年春季西南四省为应用案例,进行了植被水分的反演和时空分析,并与气象数据进行了相关性分析。结果表明:在2010年旱情中,降水对植被水分变化具有一定的影响;然而由于植被吸收降水的过程是一个滞后的过程,因而降水的变化对植被水的影响也存在一定滞后效应。在上述分析基础之上,从时间和空间尺度对植被水分在旱情监测和评估中的应用进行了评价。通过时间合成以及与其他数据(如历史数据)的结合,可克服多光谱数据的自身不足,提高多光谱遥感数据在旱情监测和评估的应用性。更多还原

【Abstract】 The vegetation is one of main drying carriers.The change of Vegetation Water Content(VWC) reflects the spatial-temporal distribution of drought situation and the degree of drought.In the present paper,a method of retrieving the VWC based on remote sensing data is introduced and analyzed,including the monitoring theory,vegetation water content indicator and retrieving model.The application was carried out in the region of Southwest China in the spring,2010.The VWC data was calculated from MODIS data and spatially-temporally analyzed.Combined with the meteorological data from weather stations,the relationship between the EWT and weather data shows that precipitation has impact on the change in vegetation moisture to a certain extent.However,there is a process of delay during the course of vegetation absorbing water.So precipitation has a delaying impact on VWC.Based on the above analysis,the probability of drought monitoring and evaluation based on multi-spectral VWC data was discussed.Through temporal synthesis and combined with auxiliary data(i.e.historical data),it will help overcome the limitation of data itself and enhance the application of drought monitoring and evaluation based on the multi-spectral remote sensing.更多还原