H085-0009
Relevance of heterogeneity of soil hydraulic material properties for predicting hillslope discharge
Relevance of heterogeneity of soil hydraulic material properties for predicting hillslope discharge
Thursday, 10 December 2020
Poster
Abstract:
The process-based description of soil water movement at larger scales remains an open challenge. This is due to the nonlinearity of the processes as well as lacking information about soil hydraulic material properties and their heterogeneity.
We investigated the impact of heterogeneity on hillslope discharge for three artificial hillslopes at the Landscape Evolution Observatory (LEO) at Biosphere 2. Although constructed the same way, the three hillslopes exhibit different discharge behaviors, most likely due to heterogeneity of soil hydraulic properties introduced during the construction of the hillslopes as well as subsequent evolution of the hydraulic properties.
We present the results of a recently performed gravity flow experiment to map the heterogeneity within the LEO hillslopes. Through constant forcing with a previously calibrated irrigation rate we were able to establish a gravity flow regime in large parts of the hillslopes, where the water content increases until the hydraulic conductivity matches the infiltration rate. Based on a dense sensor network of water content probes with colocated matric potential sensors within the hillslopes this allows us to represent the heterogeneities of the soil hydraulic properties within three-dimensional models solving Richards equation. We investigate the impact of the heterogeneity in the model representation and explore whether the added heterogeneity can qualitatively explain the different discharge behavior of the three hillslopes.
We investigated the impact of heterogeneity on hillslope discharge for three artificial hillslopes at the Landscape Evolution Observatory (LEO) at Biosphere 2. Although constructed the same way, the three hillslopes exhibit different discharge behaviors, most likely due to heterogeneity of soil hydraulic properties introduced during the construction of the hillslopes as well as subsequent evolution of the hydraulic properties.
We present the results of a recently performed gravity flow experiment to map the heterogeneity within the LEO hillslopes. Through constant forcing with a previously calibrated irrigation rate we were able to establish a gravity flow regime in large parts of the hillslopes, where the water content increases until the hydraulic conductivity matches the infiltration rate. Based on a dense sensor network of water content probes with colocated matric potential sensors within the hillslopes this allows us to represent the heterogeneities of the soil hydraulic properties within three-dimensional models solving Richards equation. We investigate the impact of the heterogeneity in the model representation and explore whether the added heterogeneity can qualitatively explain the different discharge behavior of the three hillslopes.