Modelling the initial structural dynamics of soil and sediment exemplified for a constructed hydrological catchment

• Applicant: Privatdozent Dr. Thomas Maurer
• Subject Area: Hydrogeology, Hydrology, Limnology, Urban Water Management, Water Chemistry, Integrated Water Resources Management ; Soil Sciences
• Term: from 2014 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 254461424

The initial spatial distribution of sediments in a hydrological catchment forms a starting point for ecosystem development. Analysis of eco-hydrological self-organisation require quantitative descriptions of structures and spatial heterogeneities in the sediment and in the soil. During the initial development period, the primary sediment structures are altered mainly by translocation processes, thereby subdividing the initial system in different structural compartments. It is currently unclear to what extent the future development pathway of the ecosystem and hydrological catchment depends on the initial spatial setup of such newly-emerging structures and compartments. In previous work, a process-based structure generator has been developed for the 3D modelling of initial sediment distributions within the catchment. The objective of this project is the development of a geo-pedologic modelling approach for the generation of spatial and structural heterogeneity in hydrological catchments considering formation processes and 3D solid mass balances. For this purpose, we want to further develop the existing initial structure model as an integrative tool in order to (i) analyse the spatio-temporal development dynamics depending on initial structures, and (ii) relate the simulated structural development to the (observed) hydrological behaviour. The artificially-created hydrological catchment Hühnerwasser (Lower Lusatia, Brandenburg, Germany) will serve for the model development because of the extensive monitoring data. For the description of the initial development, already established structure-generating models will be used for the simulation of erosion and deposition structures, crusts and vegetation. The parameter exchange between these models will be carried out by a special software interface (OpenMI). This genetic approach should allow for a mechanistic, process-based generation of viable sediment distribution and solid-phase structures in multiple scenarios. The 3D distributions of soil hydraulic parameter will be estimated from generated sediment properties using adapted pedotransfer functions. The impact of the structural development on the hydrological behaviour of the catchment will be evaluated by comparing model results with measured discharges. By comparing scenarios with different generated 3D sediment distributions, the impact of changing spatial structures on flow behaviour will be analysed. By identifying generalizable eco-hydrological compartments (Process Domains) from model data, results may be transferred to similar environments (e.g. post-mining and post-glacial landscapes).

• DFG Programme: Research Grants
• Participating Person: Privatdozent Dr. Horst Herbert Gerke