| Soil moisture is important, although it is a very small part of the global water resources. It links between surface water and groundwater, and it is also an important variable in the process of land circulation of water resource, and is the input parameters of the numerous hydrological model, ecological model, climate models and so on. The change of soil moisture is not only affected by soil characteristics, climate factors, topography factors, which in turn will affect the climate changes, this is a process of interaction. The traditional measuring methods of soil moisture can’t get a large area of soil moisture change in a short period of time.The study area is the wudu section of Bailong River Basin. Based on the research and experiment of radar data on soil moisture inversion, carried out the 0-10cm soil moisture inversion, with the C band ENVISAT ASAR radar data (2009 and 2010) and other auxiliary data, using the change detection method. The work will add blank hyperchromic with the inversion of soil moisture moisture using radar data on basin scales. Hoping it can provide support for the ecological environment recovery, mudslides, landslides and other geological disasters of the study in the study area.The main findings are as follow:(1) Through analysing the relationship between the vegetation water content (VWC) and the water normalized index (NDMI), gets the polynomial relationship between VWC and NDMI of the scrubby vegetation. Using the water cloud model to estimate the vegetation canopy volume scattering, gets the result that the vegetation volume scattering can be neglected, and the study does not consider the influence of vegetation.(2) The radar scattering coefficient between the soil moisture and the surface roughness showes a logarithmic relationship, through using the advanced integral equation model AIEM simulates the surface roughness. Then by using the method of change detection to eliminate the influence of surface roughness to estimate the inversion model of soil moisture. The soil moisture inversion is reliable, through verifing the accuracy of the inversion. So the inversion model of soil moisture is suitable for soil moisture inversion in a large area of grassland and cultivated land in the study area.(3) The temporal and spatial variation of soil water are:the high vaule of soil-moisture is in the northeast and southwest directions of study area, and the low value is in the channel on both sides of the slope. The spatial distribution of soil moisture content has the character of time stability.(4) By analysing the effects of soil properties, terrain factor, rainfall factors on the spatial and temporal variation of soil, gets the main findings:The relationship between soil moisture content and soil characteristics is close, sandy loam> loam> sand; slope and soil moisture is significantly negatively correlated, and the different aspect has a a significant influence on soil moisture, the sunny slope> the shady slope; elevation and soil moisture showes a significant positive correlation. |
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