Characterization of annual soil moisture response pattern on a hillslope in Bongsunsa Watershed, South Korea

Annual time series for spatially distributed soil moisture measurements are useful for identifying water distribution control factors on a hillslope scale. In this intensive 1-year field study of soil moisture on a permanent channel initiation point hillslope, high resolution digital elevation models (DEMs) of surface and bedrock, were used to analyze time series of soil moisture spatial distributions for 19 terrain indices. In linear correlations, observed soil moisture patterns were best explained by local slope and distance to channel. In nonparametric analyses, contributing area and topographic wetness index provided significant correlations to soil moisture. Terrain based modeling hypotheses were tested on time scales between 2 h and 32 days. Soil moisture time series response patterns were classified into distinct patterns based on genetic calibration of recession models and hydrologic implications. Relatively high predictability of soil moisture via topographic characteristics is attributed to high-resolution soil moisture and terrain data.