The Study of Method on Monitoring Soil Moisture in Wheat Field by NOAA/AVHRR Data

Abstract

According to the reality of agro meteorological operational services in Henan Province and based on systematic researches into the monitoring theories,models,data processing,index and application technique of NOAA/AVHRR remote sensing,the monitoring model of NOAA/AVHRR remote sensing on winter wheat drought has been developed.Some questions existing in this field such as the influence of various soil types and wind velocity on the remote sensing monitoring for drought,the coupling of soil surface layers moisture with that of the deep layers and the method for retrieving soil moisture using single phase remote sensing data etc.,have been further studied with GIS technology.The results showed that the retrieving effects of distinguishing soil types are better than those of undistinguishing soil types,the influences of wind velocity in retrieving moisture of soil surface layers should be considered,but not in deep soil layers and the effects that retrieve the deep soil layers moistures in terms of the soil surface moisture obtained by remote sensing are better than these creating statistical models directly by distinguishing soil types,because a good nonlinear relation exists between the soil surface layer mositure and deep soil layers moisture.Under the condition of considering the factors of temperature and vegetation,the accuracy of retrieving soil moisture by means of single phase remote sensing data is a little bit higher than that by using the method of thermal inertia.The basic integrating application of GIS and RS has been realized and the accuracy of integrating for remote sensing drought has been improved with some connection software.Finally,the application services system of monitoring winter wheat drought in Henan Province has been established.