REPOSITORY
JÜLICH ZWISCHENSCHOLLE
SOILPROM Use-case 3: Jülich Zwischenscholle
Section 1: General description
A coupled saturated-unsaturated water flow and solute transport model, consisting of four components:
- HYDRUS-1D for water flow and pesticide transport in the unsaturated soil (vadose zone)
- MODFLOW for groundwater flow
- MT3DMS for solute transport in groundwater
- ParFlow-CLM outputs of the daily water-table depth, either from the DE06 simulation over Germany at about 0.6 km resolution (Belleflamme et al., 2023) or from the ParFlow-CLM simulation over Europe at 3 km resolution (Naz et al., 2023).
The models are coupled with Python scripts. The daily water-table depth from ParFlow-CLM sets the lower boundary of HYDRUS-1D (one-way coupling).
The coupled HYDRUS-1D–ParFlow-CLM model was tested at 62 sites in Germany to evaluate how the choice of publicly available climate data, such as ERA5-Land or the European Climate Assessment and Dataset (ECA&D) stations, affects the modelling results. In addition, the effect of the lower boundary condition, such as a variable groundwater level or deep groundwater (free drainage), on groundwater recharge and pesticide leaching into the groundwater was assessed. The fully coupled system with MODFLOW and MT3DMS is in development and will then be evaluated against measured groundwater concentration data from the Jülich Zwischenscholle aquifer.
Figure 1. Aerial view of the Jülich Zwischenscholle area
Figure 2. The 62 sites in Germany simulated with HYDRUS-1D (ECA&D station locations)
Section 2: Links to download executables
Section 3: Coupling scripts
Hydrus1D_Batch.ipynb: Python workflow that builds the HYDRUS-1D input files for every site (soil profile, daily atmospheric forcing, pesticide application and, for the variable water table, the ParFlow-CLM lower boundary) and runs HYDRUS-1D in batch.
Section 4: Simulation example
Example simulations for Ahaus, a site with a shallow water table (median depth about 0.4 m), with pesticide A and ECA&D forcing, for both lower boundary conditions.
Each zip file contains the Excel input tables (Datafiles) and, in Hydrus1D_input_output, the HYDRUS-1D input files (SELECTOR.IN, PROFILE.DAT, ATMOSPH.IN, HYDRUS1D.DAT) together with the output files of the example run with HYDRUS-1D 4.17 (e.g. Obs_Node.out, solute1.out, T_Level.out). The daily water-table depth for the variable water table example is taken from the ParFlow-CLM DE06 outputs.