基于作物水分胁迫指数的表层土壤含水率遥感估算  

Estimating Topsoil Water Content Using Crop Water Stress Index and Remote Sensing Technologies

作　　者：林人财 陈鹤[1] 张德宁 魏征[1] 蔡甲冰[1] 曾冉 张丽莉 贾玉玲 LIN Rencai;CHEN He;ZHANG Dening;WEI Zheng;CAI Jiabing;ZENG Ran;ZHANG Lili;JIA Yuling(State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Operation and Maintenance Center of Panzhuang Irrigation District,Dezhou 253000,China;Cangzhou Water Conservancy Engineering Quality Technology Center,Cangzhou 061000,China)

机构地区：[1]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038 [2]德州市潘庄灌区运行维护中心,山东德州253000 [3]沧州市水利工程质量技术中心,河北沧州061000

出　　处：《灌溉排水学报》2023年第4期1-7,共7页Journal of Irrigation and Drainage

基　　金：国家重点研发计划项目(2021YFB3900602);中国水利水电科学研究院流域水循环模拟与调控国家重点实验室自主研究课题(SKL2022TS13);中国水利水电科学研究院基本科研业务费专项项目(ID0145B022021,ID0145B052021)。

摘　　要：【目的】探究作物水分胁迫指数(CWSI)与表层土壤含水率的空间分布特征,并分析不同下垫面(葵花、夏玉米、春小麦和甜椒)表层土壤含水率的遥感估算精度。【方法】利用MOD16A2遥感数据和气象数据,结合Penman-Monteith(P-M)模型,基于CWSI反演河套灌区解放闸灌域表层土壤含水率,并对不同下垫面的表层土壤含水率进行验证。【结果】CWSI的空间分布与表层土壤含水率相反,CWSI大的区域,表层土壤含水率小;春小麦下垫面遥感估算的表层土壤含水率效果较好,决定系数(R^(2))为0.748,其次为葵花,R^(2)为0.357;灌溉次数较多的夏玉米和甜椒的表层土壤含水率估算精度较差,可见基于CWSI的表层土壤含水率遥感估算方法对土壤干旱较为敏感。【结论】基于CWSI的表层土壤含水率遥感估算方法更适用于灌水较少且耐旱作物下垫面的表层土壤含水率估算。【Objective】Change in topsoil water content is intricately linked to plant transpiration,and understanding its spatiotemporal variation at large scales is crucial to improving water and agriculture management.The objective of this paper is to investigate the feasibility of remote sensing for estimating topsoil water content,its association with crop water stress index(CWSI)and the impact of cropping systems.【Method】The experiment site was an irrigation field at Jiefangzha in Hetao Irrigation District.The topsoil water content in different cropped lands(sunflower,summer maize,spring wheat and pepper)was calculated,inversely,in 2014 using the MOD16A2 imagery,meteorological data,and the P-M model and CWSI.The estimated soil water content was compared with ground-truth data.【Result】The CWSI and topsoil water content were inversely proportional.The method was accurate for estimating topsoil water content in wheat and sunflower lands,with the determination coefficient between the estimated and measured soil water content for the wheat and sunflower lands being 0.748 and 0.357,respectively.However,it was less accurate for maize and pepper lands as they were irrigated more frequently.These suggested that the remote sensing-based method works better when the soil is dry than when it is wet.【Conclusion】The CWSI-based remote sensing method is more suitable for estimating topsoil water content in lands planted with drought-tolerant crops than lands grown with water-demanded crops which need more irrigation.Our results provide insight into the impact of cropping systems on accuracy and reliability of remote sensing methods for estimating topsoil water content.It has potential application for agricultural management in arid and semi-arid regions.

关 键 词：土壤含水率 CWSI MOD16A2 解放闸灌域 

分 类 号：S161[农业科学—农业气象学]