Comparison of CWSI and T_(s)-T_(a)-VIs in moisture monitoring of dryland crops(sorghum and maize)based on UAV remote sensing  

作　　者：Hui Chen Hongxing Chen Song Zhang Shengxi Chen Fulang Cen Quanzhi Zhao Xiaoyun Huang Tengbing He Zhenran Gao 

机构地区：[1]College of Agriculture,Guizhou University,Guiyang 550025,China [2]Institute of New Rural Development,Guizhou University,Guiyang 550025,China [3]Institute of Rice Industry Technology Research,College of Agricultural Sciences,Guizhou University,Guiyang 550025,China

出　　处：《Journal of Integrative Agriculture》2024年第7期2458-2475,共18页农业科学学报（英文版）

基　　金：supported by the National Key Research and Development Program of China(2022YFD1901500/2022YFD1901505);the Key Laboratory of Molecular Breeding for Grain and Oil Crops in Guizhou Province,China(Qiankehezhongyindi(2023)008);the Key Laboratory of Functional Agriculture of Guizhou Provincial Higher Education Institutions,China(Qianjiaoji(2023)007)。

摘　　要：Monitoring agricultural drought using remote sensing data is crucial for precision irrigation in modern agriculture.Utilizing unmanned aerial vehicle(UAV)remote sensing,we explored the applicability of an empirical crop water stress index(CWSI)based on canopy temperature and three-dimensional drought indices(TDDI)constructed from surface temperature(T_(s)),air temperature(T_(a))and five vegetation indices(VIs)for monitoring the moisture status of dryland crops.Three machine learning algorithms(random forest regression(RFR),support vector regression,and partial least squares regression)were used to compare the performance of the drought indices for vegetation moisture content(VMC)estimation in sorghum and maize.The main results of the study were as follows:(1)Comparative analysis of the drought indices revealed that T_(s)-T_(a)-normalized difference vegetation index(TDDIn)and T_(s)-T_(a)-enhanced vegetation index(TDDIe)were more strongly correlated with VMC compared with the other indices.The indices exhibited varying sensitivities to VMC under different irrigation regimes;the strongest correlation observed was for the TDDIe index with maize under the fully irrigated treatment(r=-0.93).(2)Regarding spatial and temporal characteristics,the TDDIn,TDDIe and CWSI indices showed minimal differences Over the experimental period,with coefficients of variation were 0.25,0.18 and 0.24,respectively.All three indices were capable of effectively characterizing the moisture distribution in dryland maize and sorghum crops,but the TDDI indices more accurately monitored the spatial distribution of crop moisture after a rainfall or irrigation event.(3)For prediction of the moisture content of single crops,RFR models based on TDDIn and TDDIe estimated VMC most accurately(R^(2)>0.7),and the TDDIn-based model predicted VMC with the highest accuracy when considering multiple-crop samples,with R^(2)and RMSE of 0.62 and 14.26%,respectively.Thus,TDDI proved more effective than the CWSI in estimating crop water content.

关 键 词：MAIZE SORGHUM T_(s)-T_(a)-VIs CWSI UAV machine learning crop moisture monitoring 

分 类 号：S127[农业科学—农业基础科学]