EGU21-2848, updated on 03 Mar 2021
https://doi.org/10.5194/egusphere-egu21-2848
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Hillslope-scale mapping and numerical representation of the subsurface heterogeneity towards an improved process-based hydrological modelling

Edoardo Martini1,2, Ute Wollschläger3, Marco Bittelli4, Fausto Tomei5, Ulrike Werban2, Steffen Zacharias2, and Kurt Roth1
Edoardo Martini et al.
  • 1University of Heidelberg, Institute of Environmental Physics, Germany (emartini@iup.uni-heidelberg.de)
  • 2Dept. Monitoring and Exploration Technologies, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
  • 3Dept. Soil System Science, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
  • 4Dept. Agricultural Sciences, University of Bologna, Italy
  • 5Hydro-Meteo-Climate Service, ARPAE Emilia-Romagna, Bologna, Italy

One of the major challenges in soil hydrological modelling is due to the fact that soils are heterogeneous at all spatial scales. The identification and accurate representation of such heterogeneity can be crucial for quantifying the subsurface hydrological states and water fluxes.

This work presents the results of an integrated approach for process-based soil hydrological modelling for a highly instrumented hillslope site. The approach builds on the integration of classical soil mapping, on accurate monitoring of soil water dynamics as well as on geophysical measurements for characterising subsurface heterogeneity. It finally integrates the gathered information into a physical model for simulating the soil water dynamics with high spatial and temporal resolution.

At the Schäfertal Hillslope site (Central Germany), the soil monitoring network STH-net provides high-quality data about the soil water dynamics and soil properties at 8 instrumented soil profiles and depths within the unsaturated zone. The soil spatial variability, known from local soil description and sampling, was mapped using time-lapse electromagnetic induction measurements. The geophysical inversion of the data provided depth-resolved information about the subsurface structures in terms of soil-bedrock interface, soil horizons and their spatial continuity along the hillslope transect. Based on this, different versions of the subsurface geometry model were produced and associated to soil hydraulic parameterizations derived from different approaches.

We show the performance of the physical model CRITERIA-3D in reproducing the soil water dynamics for different subsurface models with increasing complexity. Specifically, we highlight and discuss the key challenges that need to be addressed when continuous information about the subsurface heterogeneity is to be mapped in the field with high resolution and represented in a numerical model with fine discretization in three-dimensions.

We conclude that linking state-of-the-art experimental methods to advanced numerical tools, and bridging the gap between different disciplines such as pedology, hydrology and geophysics can be the key for improving our ability to measure, predict and better understand the vadose-zone processes. This will provide important knowledge needed for transferring this approach to larger scales where the accurate quantification of the soil water fluxes is required for a more efficient water management in the context of sustainable food production and climate change.

How to cite: Martini, E., Wollschläger, U., Bittelli, M., Tomei, F., Werban, U., Zacharias, S., and Roth, K.: Hillslope-scale mapping and numerical representation of the subsurface heterogeneity towards an improved process-based hydrological modelling, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2848, https://doi.org/10.5194/egusphere-egu21-2848, 2021.

Displays

Display file