Opportunities for Improved Integration of Soil Science and Catchment Hydrologic Modeling
Abstract
Estimating spatially-variable parameter values for physically-based models presents a major challenge in catchment hydrology. Characterization of subsurface heterogeneity and natural structures associated with pedogenesis and bioturbation therefore has great potential to inform integrated hydrologic models. Soil structures at the pore and pedon scale have an aggregated influence on the hydraulic properties needed to simulate the flow of water and transport of solutes at the hillslope, catchment, and watershed scales. Similarly, inverse model estimates of effective hydraulic properties based on observed hydrologic-response to natural rainfall are useful for identifying the hydraulically important soil structures, weathering horizons, and natural heterogeneities. This work presents examples of hydrologic response for selected experimental catchments simulated with a fully-coupled surface/ subsurface flow model in combination with a variety of field experiments in soil physics. The simulations illustrate the influence of soil horizons, hydraulic properties, topography, and surface roughness on variably-saturated subsurface flow dynamics. The experimental data highlight the importance of soil structures and heterogeneity on preferential flow and soil-water retention at different scales. Catchments in disturbed landscapes (e.g., wildfire, insect and disease, military activities, forestry) are also included because soil properties and structure are often impacted by disturbance, which in turn affects hydrologic processes. These examples help demonstrate the great potential for synergistic integration of detailed soils characterization with the prediction of runoff generation and streamflow at the scales needed in the land and water resources management arena. As we face increasing pressure on water resources resulting from climate and land use impacts, merging concepts in soil science and catchment hydrology can a play critical role.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.H32D..03M
- Keywords:
-
- 1875 HYDROLOGY Vadose zone;
- 1804 HYDROLOGY Catchment;
- 1850 HYDROLOGY Overland flow;
- 1847 HYDROLOGY Modeling