Remote Sensing Research And Application Of Soil Moisture In The Middle Part Of Jilin Province

Soil water is the important water resource on earth. It takes an important roleduring the formation, transformation and consumption process of the water resource.The soil moisture is also the core and link of the system of Atmosphere, vegetation,soil and groundwater. Monitoring soil water content, ie soil moisture, is importantlymeaningful on agricultural production, drought monitoring, irrigation and watermanagement, water resources management.The theories of remote sensing study on soil moisture are mature. According tothe study theories home and abroad of recent years, this paper uses the remote sensingmethod to monitor the soil moisture of the middle part of Jilin Province. Remotesensing images of MODIS_L1B, MOD11A2, MOD13A2and MCD12Q1are used asdata resources to calculate the relevant parameters of the soil moisture inversionmodel. Split window algorithm is used to calculate the land surface temperaturerequired by the Apparent Thermal Inertia (ATI) model. According to the0~10cmactually measured soil moisture data supplied by the National Meteorological Center,Apparent Thermal Inertia(ATI) is used to calculate the study area’s soil moisture oflow vegetation cover. Feature space of surface temperature-vegetation index isestablished, of which the dry and wet edge is calculated through linear fit to the studyarea’s temperature vegetation dryness index (TVDI) of high vegetation cover. Aboveall, monitoring soil moisture of study area by remote sensing Technology is realized.The study result shows that in low vegetation cover time, the ATI model has highcorrelation with actually measured soil moisture and the correlation coefficient is0.831. During the high vegetation cover time, TVDI has correlation with actuallymeasured soil moisture and the correlation coefficient is in the range of0.473~0.705.According to the soil types data of the study area and the soil moisture imagecalculated by ATI, distribution difference of soil moisture of the study area inNon-wet period is analysis. The moisture of clay soil in the image is during85%~90%. The moisture of clay loam soil and loam soil in the image is during80%~85%. The soil moisture of sandy loam soil is during75%~80%. Such result isconsistent with the water-retention capacity of the soil type, which shows that soilmoisture calculated by ATI model accords with the actual situation of soil moisture. According to the study area’s land cover image and the TVDI grades, statistics ofdistribution rate of each kind of land cover in every TVDI grade is made. Relationbetween the land cover type and soil moisture is discussed. The statistic result showsthat during the same time, paddy field of study area is in the normal and wet situation.Dry farmland is in the wet, normal, dry range. Woodland is in the wet, very wetsituation, of which the soil moisture is the best, the soil water retention capacity isstrong. The meadow is in the dry, very dry situation, of which the soil moisture is theworst. The same land cover type in different years2004,2005and2006is changinggradually. The Woodland has extracting wet area year by year. The meadow is in thedry situation all the time.