- 1Budapest University of Technology and Economics, Faculty of Civil Engineering, Department of Sanitary and Environmental Engineering, , Műegyetem rkp. 3. H-1111 Budapest, Hungary
- 2Institute for Soil Sciences, HUN-REN Centre for Agricultural and Environmental Research, Budapest, 1022, Hungary
- 3National Laboratory for Water Science and Water Security, Budapest University of Technology and Economics, Faculty of Civil Engineering, Department of Sanitary and Environmental Engineering, Műegyetem rkp. 3. H-1111 Budapest, Hungary
There is a recurring question in environmental science, whether the spatial heterogeneity of soils is also accompanied by notable variation of soil hydrological behaviour. Our aim was to investigate this so-called “structural heterogeneity versus functional homogeneity” issue by using variably saturated zone simulations and the Hungarian soil database MARTHA v3.1.4. The purpose of the applied functional classification method is to simulate the water balance components of different soils under the same meteorological forcing and then cluster them based on their hydrological response.
We used 2552 soil samples with adequate data availability (fitted van Genuchten parameters of the soil moisture retention curve, saturated hydraulic conductivity) to set up and run 200 cm deep homogeneous soil profile models in Hydrus-1D, which differed only in their soil hydraulic parametrization. The simulations covered a 1 year period with daily time steps. Two types of upper boundary were applied: (i) 1 mm/day constant precipitation for 30 days then no precipitation, (ii) measured precipitation time series from Hungary over the whole period. The bottom boundary condition was free drainage.
Hydrological indicators were derived from the simulation results (surface runoff, average root zone saturation, storage change, bottom boundary flux, flowthrough volume at 40 cm depth, break through curve characteristics for the constant precipitation). These indicators were used to classify the soil profiles using k-means clustering.
1984 simulations were successful, from which 9 clusters were formed. These represent distinct hydrological behaviour for the same forcing time series, indicating the applicability of the proposed classification method.
Key words: soil hydrology, functional evaluation, Hydrus-1D, MARTHA database
The research presented in the article was carried out within the framework of the Széchenyi Plan Plus program with the support of the RRF 2.3.1 21 2022 00008 project.
How to cite: György, M., Ács, T., Decsi, B., Kolcsár, R., Bakacsi, Z., Makó, A., Szabó, B., and Kozma, Z.: Structural heterogeneity versus functional homogeneity - hydrological soil clustering of the MARTHA database, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11586, https://doi.org/10.5194/egusphere-egu25-11586, 2025.
