Spatial Variability of Surface Soil Moisture in Semi-arid Region of Northern China

In this study, the spatial pattern and correlation of surface moisture content over the Jinghe River Basin, was investigated by using in-situ measurements and remotely sensed data. First of all, the spatial pattern of the soil moisture content was retrieved from the MODIS imagery based on a statistical relationship between the Temperature Vegetation Dryness Index (TVDI) and in-situ soil moisture measurements over the basin, then the geo-statistic analysis methods and semi-variogram function were applied on the derived soil moisture for investigating the spatial correlations of soil moisture content. It was found that the magnitude of the field measured soil moisture content was correlated with the adjacent pixels especially for the samples from the same land use type. The correlation length, which is increasing with the topographical attribute, can be detected and validated from the statistical characteristics of in-situ soil moisture measurements and remotely sensed data.