中国农业大学学报2024，Vol.29Issue(5)：149-158,10.DOI:10.11841/j.issn.1007-4333.2024.05.14
基于指数滤波法的中国区域深层土壤水分估算
Estimation of subsurface soil moisture in China based on exponential filtering method
摘要
Abstract
Microwave remote sensing technology is able to realize the observation of regional-scale surface soil moisture,but the deep soil moisture is more closely related to ecological,hydrological and agricultural fields.How to estimate deep soil moisture from surface soil moisture is still a scientific problem to be solved.This study utilized multi-layer soil moisture data from 2 121 soil moisture observation stations across China(Data do not include those of Hongkong,Macao and Taiwan region.The same below)and investigated the application of the exponential filtering method.Based on 10 cm soil moisture data,the exponential filtering method was applied to estimate soil moisture at depths of 20 cm,30 cm,40 cm,and 50 cm,respectively.The results show that:1)With the increase of soil depth,the estimation accuracy of exponential filtering method gradually decreases.The median values of NSE(Nash efficiency coefficient)are 0.76,0.54,0.39 and 0.28 corresponding to the four depths,respectively.The median values of R2(determination coefficient)are 0.86,0.73,0.64 and 0.59,respectively,and the median values of RMSE(Root mean square error)are 0.023,0.027,0.028 and 0.028 m3/m3,respectively;2)It is feasible to estimate subsurface soil moisture from the median value of the calibrated T,especially for shallow soil moisture(such as 20 cm)estimation.Compared with using calibrated T value,NSE difference is less than 0.05 at 93％sites and RMSE difference is less than 0.001 at 82％sites;3)The better the correlation between surface and subsurface soil moisture,the higher the estimation accuracy of exponential filtering method.The above results suggest that the EF method has good performance in China.Supported by a large number of measured data,T values of 2,5,10 and 14 d corresponding to the depths of 20,30,40 and 50 cm,respectively,can be used as references in China when using the EF method with 10 cm soil moisture.关键词
表层土壤水分/深层土壤水分/指数滤波法/中国区域/土壤水分观测站Key words
surface soil water content/subsurface soil water content/exponential filter method/China/soil moisture sites分类
天文与地球科学引用本文复制引用
田静..基于指数滤波法的中国区域深层土壤水分估算[J].中国农业大学学报,2024,29(5):149-158,10.基金项目
鄂尔多斯市科技计划项目(2022YY007) （2022YY007）
国家自然科学基金项目(42071327) （42071327）
