4. Conclusions
In this study, we developed a data combination approach on the basis of EOF analysis of space-time soil moisture data at a reference Shale Hills catchment. We investigated the space-time characterization of soil moisture and found that the variation of soil moisture could be explained by using the first few EOFs. Results of the correlation analysis showed that topography and soil properties have mixed effects on the variability explained by the dominant soil moisture EOFs. Benefits based on the derived underlying stable EOF patterns of soil moisture, the relationships between site characteristics and the EOF patterns were examined to conduct a spatial-temporal dataset combination. Based on the long-term spatial extensive sampling campaign and the specific transect of real-time monitoring, this study investigated how to integrate the spatially extensive, but temporally limited manual datasets with the temporally extensive, but spatially limited automated monitoring datasets. This exercise was helpful for understanding the soil moisture spatio-temporal patterns and the hydrological responses at a small landscape scale, and are considered to be important factors for the effective measurement and the practical management of soil moisture at multiple scales.