Research On Monitoring And Evaluation Technology Of Corn Waterlogging Based On Remote Sensing

In my country,the precipitation in summer is influenced by the temperate continental monsoon climate,which usually accounts for 60%to 70%of the annual precipitation.As is known to all,flood and waterlogging disasters will have a significant impact on agricultural production,and corn is just a kind of crop that is not tolerant to waterlogging.Therefore,excessive rainfall often leads to waterlogging disasters,which will hinder the growth of crops and lead to a large reduction in production.Corn is one of the most important safe grains in China,accounting for 34.4%of the total grain output in China.Therefore,the identification,monitoring and early warning of crop waterlogging have important guiding significance for rapid damage assessment,insurance claims and disaster risk reduction.In the past,flood and waterlogging disaster identification was mainly based on river and urban waterlogging,and mostly based on water depth and precipitation.However,there were few studies on agricultural waterlogging,and due to the complex growth cycle and physiological characteristics of corn crops,precipitation and water depth could not meet the identification needs of agricultural waterlogging.For existing agricultural waterlogged identification of meteorological index and means of remote sensing,remote sensing means more recognition and monitoring of the range,higher space resolution,but is limited by the time resolution,unable to guarantee the stability of the data acquisition and the previous research of remote sensing monitoring of corn floods and LaoHai research,there is no clear correlation analysis for corn waterlogging degree.Based on remote sensing monitoring and evaluation technology of maize waterlogging in anhua agricultural insurance co.,LTD.,jilin province,this paper studies the sensitivity of waterlogging damage and waterlogging damage to remote sensing spectrum of maize in important growing period by simulating waterlogging of maize in artificial experimental field.,planting experiment way of corn field simulation was adopted to control water for different growth period of maize,waterlogging occurs between 90%and 100%relative water content of soil control,when the LaoHai control water in soil surface more than 3 cm,with water stress days as victims,corn LaoHai set the gradient of 1 day,3 days,five days,7 days,9 days,gradient waterlogging set corn for three days,five days,7 days,9 days.Spectral information and chlorophyll information were collected after maize stress and recovery for 15 days.The monitoring and evaluation method of maize under waterlogging was established by analyzing the changes of canopy spectral curve,spectral characteristics,chlorophyll content and final yield loss of maize.According to the analysis results of post-disaster changes,the vegetation index sensitive to the degree of stress was selected from the extracted spectral characteristic parameters and different vegetation indexes.The results of spectral analysis showed that with the increase of stress days in jointing stage and grouting stage,the value of near-infrared band decreased and the value of visible light increased,and the characteristic parameters such as the amplitude of red edge and the area of red edge also showed significant differences.In addition,according to the analysis of the changes in vegetation index,RVI and NDVI,GNDVI on corn waterlogged before the identification recovery effect is obvious,according to the same phase under the three planting was index difference degree,establishing the jointing stage and milking stage of corn waterlogged monitoring model,and construct a waterlogged corn chlorophyll,remote sensing estimation model of production,as corn waterlogged disaster evaluation basis,and finally to jointing stage and milking stage corn LaoHai and different level of waterlogging remote sensing monitoring and evaluation method is given.In this paper,Planet satellite data from August 1,2019 were used to monitor waterlogged maize at jointing stage in some maize growing areas in yushu,jilin province through remote sensing monitoring model,and relative losses of waterlogged maize in this area were evaluated with the estimation model.The correlation between remote sensing monitoring model and relative soil moisture monitoring model is analyzed,and the feasibility of remote sensing monitoring to replace soil moisture monitoring is discussed.