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土壤水分一直是土壤学领域中较为活跃的研究内容,是陆面过程与水循环的重要影响因素。以AMSR-E为代表的被动微波遥感技术的发展为土壤水分的研究提供了方便,但是其粗糙的空间分辨率限制了其在中小尺度内的应用。因此,本研究利用MODIS温度产品MOD11A2和归一化植被指数产品MOD13A3构建了月时间尺度下的温度植被干旱指数(TVDI);其次,利用温度植被干旱指数TVDI和土壤水分之间的线性负相关关系,对AMSR-E三级土壤水分反演产品进行空间降尺度研究,获取2003年连续月时间尺度下空间分辨率为1 km的土壤水分反演结果,并利用地面实测土壤水分数据对反演结果进行验证。地面实测土壤水分值与降尺度反演结果显著相关,每月的线性相关决定系数均在0.8以上,表明降尺度后的土壤水分反演结果具有较高的精度,能够用来表示土壤水分的分布特征。
Soil moisture has always been a more active research area in soil science and is an important factor affecting land surface processes and water cycle. The development of passive microwave remote sensing technology represented by AMSR-E is convenient for the study of soil moisture, but its coarse spatial resolution limits its application in small and medium-scale. Therefore, in this study, MODDI temperature MOD11A2 and normalized NDVI MOD13A3 were used to construct the TVDI on a monthly time scale. Secondly, based on the linear negative correlation between TVDI and soil moisture , The spatial scale reduction of AMSR-E three-stage soil moisture retrieval products was carried out. The retrieval results of soil moisture with spatial resolution of 1 km at successive monthly time scales in 2003 were obtained. Based on the measured data of soil moisture, authenticating. The measured soil moisture values on the ground are significantly correlated with the downscaling inversion results, and the monthly linear correlation coefficients are all above 0.8, indicating that the soil moisture inversion results after the downscaling are of high precision and can be used to represent the soil moisture Distribution characteristics.