Research On Waterlogging Based On Active Microwave Remote Sensing Data

Waterlogging is defined as a kind of meteorological disaster that caused by the saturation of the soil by groundwater,it is sufficient to prevent or hinder agriculture to growth normally.Crop yields will be reduced rapidly after suffering from waterlogging.Thus,monitoring the waterlogging is meaningful.There are many factors contributing to the waterlogging,such as:precipitation,sunshine duration etc.However,the same meteorological condition do not have the same severity of the calamities,the saturation of soil moisture is the core reason.Waterlogging can be monitored by the surface soil moisture data.In this research,surface soil moisture was calculated from the active microwave remote sensing data,and the waterlogging was monitored by the soil moisture data:(1).totally 2158 images of ASAR-GM data in HH polarization was collected to calculated the surface soil moisture based on the Change Detection Algorithm.The result was evaluated by the in-situ soil moisture data from the Agricultural-Meteorological station which is provided by the meteorological Bureau of Jiangsu,Anhui and Hubei provinces.The result shows that the RMSE is 0.119cm~3/cm~3,correlation coefficient is 0.54.The higher the surface soil moisture,the higher probability of the waterlogging.(2).considering that the condition of waterlogging is occurred when the relative surface soil moisture is higher than 90%,and the duration is longer than 10 days.Monitoring the waterlogging with the soil moisture product from the active microwave remote sensing data:ERS-1/2 and ASCAT.The first day and the last day when the soil moisture is higher than 90%was recorded,the disaster process was monitored.The result shows great correlation with the precipitation data and reference records.