QUANTIFICATION OF SOIL HYDRAULIC PROPERTIES USING REMOTELY SENSED SOIL MOISTURE |
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학술지명 2015 SWGIC
저자 채효석,신용철,박경원,황의호,정영훈
발표일 2015-11-03
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Pixel-based soil moisture footprints have become a critical component for many meteorological/hydrological models with the increasing availability of remote sensing (RS) techniques (Shin et al., 2013). However, the presence of shallow groundwater (SGW) table depths in unknown field regions limits the availability of RS products. Thus, we developed a dynamic ground water (DGW) data assimilation approach that considers SGW table depths (oscillations) across time to quantify effective soil hydraulic properties in the unsaturated zone. Numerical experiments that included synthetic and field validation experiments were conducted to verify the DGW data assimilation scheme. The Little Washita watershed in Oklahoma and the Olney/Bondville sites in Illinois were selected under different hydro-climatic regions for the numerical studies. We tested the DGW scheme using various soil textures and vegetation cover with fixed and dynamically changing SGW table depths across time in the homogeneous and heterogeneous (layered) soil columns. The DGW-based soil parameters matched the observations under the various synthetic conditions better than those that only considered the fixed groundwater table depths in time. Our proposed data assimilation scheme performed well for predicting the effective soil hydraulic properties and SGW table oscillations at point, airborne sensing, and satellite scales, although uncertainties exist. These findings support the robustness of our proposed DGW approach for field applications. Thus, this scheme could help improve the availability and applicability of RS soil moisture footprints under various hydro-climate regions. |