Scale-dependency of spatial variability of soil moisture on a degraded slope-land on the Loess Plateau

In order to explore the impacts of scale on the spatial variability of soil moisture, a study in a 60 m × 60 m sloping land area was carried out, spatial variation of soil moisture was analyzed with all the data measured under 2 m × 2 m sampling grid with TDR, then, re-sampling technique was employed with changing sampling extents and spacing, and spatial variation of each scenario was also determined. In the process of data analysis, three indices commonly used in spatial analysis including coefficient of variation, correlation length and Moran'I index were applied to each scenario to characterize the degree of spatial variability of soil moisture, at the same time, some related issues of scale-dependency were discussed. The results showed that all the indices measured increased with various degrees with increasing extent. However, spacing did not affect coefficient of variation and Moran'I index, while correlation length decreased with the increase of spacing.