Contribution of Environmental Factors to Soil Moisture and Their Scale Effect on the LOESS Plateau, China

Mei-li GUO, Hai-li RU, Feng JIAO


Environmental factors have great impact on soil moisture. Despite their great contribution to the spatial distribution and variability of soil moisture, how they changes over the scales remains poorly understood. Here we examined the contribution of eight environmental factors to the soil moisture at three scales (slope scale, small watershed scale and regional scale) on the Loess Plateau, China. Our study showed that as the scale increased from slope to regional scale, the contribution of climatic factors generally increased, whereas that of topographical factors generally decreased. Consequently, the information provided by slope position (Slpo) slowly turned to that of slope gradient (Slga), mean annual precipitation (Pma), mean annual temperature (Tma) and other climatic factors. The shifting of the information in our study could also be associated with the changes of determinant and main limiting factors among the different scales. These results suggested that the temporal and spatial variability of soil moisture as well as its dominant factors are different over time and space. They are determined by scale effect of environmental factors that influence soil moisture.


Loess Plateau, Soil moisture, Environmental factors, Scale effect


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