中文摘要：

针对基于植被指数反演不同生长期、不同冠层结构特征下玉米冠层含水量的序列性研究较少,冠层含水量反演较低等问题,优选不同生长期玉米冠层含水量反演最佳植被指数,完成玉米冠层含水量高精度提取。初步选择4种可靠性强的水分指数：归一化植被指数、归一化水体指数1、归一化水体指数2、水协迫指数,分别基于PROSAIL辐射传输模型、三期实测冠层含水量及同步Landsat-8OLI数据,模拟分析4种植被指数与冠层含水量的关系,优选不同生长期玉米最佳水分指数,实现玉米冠层含水量快速精确反演。实例验证结果表明,水分指数归一化水体指数1可作为植被冠层含水量反演的最佳指数且反演精度随着植被含水量的增加而降低,在玉米生长初期,中误差为0.13kg/m~2,在生长中后期,中误差达到0.582kg/m~2,满足生长初期玉米冠层含水量快速反演需求。研究结果可为植被冠层含水量反演中水分指数选择提供参考,也可为稀疏植被覆盖区土壤水分反演研究提供借鉴。

英文摘要：

In order to meet the accuracy of corn canopy water content under different growth stages and different canopy structure characteristics,this paper chooses corn best canopy water content index under different growth stages,and achieves corn canopy water content high precision extraction.Firstly,we select four reliable indices which are NDVI,NDII1,NDII2 and MSI.Secondly,we use the PROSAIL model and measure vegetation canopy water content and the synchronous Landsat-8OLI data of three growth periods to simulate the relationship between four indices and vegetation canopy water content,respectively,and optimize the most reliable index under different growth stages.Then,we can realize rapid and accurate extraction of corn canopy water content.Case verified results show that,moisture index NDII1 is the best vegetation canopy water content inversing index,and also,inversion precision decreases with the increase of the vegetation canopy water content;in the early growth of corn,Root Mean Square Error（RMSE）is 0.13kg/m2,and in the middle and late growth stages of corn,RMSE runs up to 0.582kg/m2;moisture index NDII1 satisfies the rapid inversion of early-growth stage corn VCWC.The study results can provide technical methods and reference for the water index choice in vegetation canopy water content inversion,and can provide references for soil moisture retrieval under bare vegetation.