Research Focus

• Modelling of hydrologic systems and optimisation
• Hydrology in arid areas, water scarcity and irrigation
• Stochastical modeling of hydrosystems
• Hydrologic processes in small and medium sized catchments

In the basic research-oriented core area of "hydrosystem modelling and optimisation" (TEAM Computational Hydrology), new simulation-based optimisation methods for integrated resource management are developed and management problems with limited water resources are investigated.
In the search for suitable solutions, the improvement of temporal and spatial water availability, but also the targeted control of water demand are considered simultaneously. Of interest are issues that arise, as in the case of irrigation systems, due to a complex interaction of the relevant hydrological processes that take place at different temporal and spatial scales. The main challenge in this field is the development of methods to integrate computationally intensive simulation models into robust optimisation procedures that simultaneously consider model uncertainties and reduce these by calibrating them to the management problem.

The application-oriented core area "hydrology of arid areas, scarcity of water and irrigation" (TEAM Applied Hydrology) focuses on sustainable water resources management in arid and semi-arid areas using smart controlling and optimisation approaches. Past research projects, in collaboration with Oman, Ethiopia, France and Syria, focused on optimisation of multipurpose reservoir-systems considering serious stakeholder conflicts and applying ready to use tools to increase water productivity of irrigation systems on a lab- or field-scale to catchment-scale (TEAM Computational Hydrology). The experiences from these research projects show that modelling, simulation and experiments must be connected through an interactive way of viewing and interpreting processes and results. Cooperation, for example with UNU-FLORES in Dresden amongst others, contribute to the transformation of integrated management of natural resources like water and soil in emerging and developing countries.

The core area "stochastic hydrosystem modelling" (TEAM Stochastic Hydrology) uses innovative probabilistic modelling techniques in coupled hydrological systems. Robust model forecasts and scenario simulation require the consideration and treatment of dominant uncertainty sources, such as errors in the data, parameters and the model structure, but also scaling errors.
A wholistic treatment of uncertainty sources is technically demanding, limited by computation time, often data-intense, and therefore hardly applicable in practice. Our corresponding research topics are:

• Discrimination and priorisation of sources of uncertainty,
• Development of diagnostic tools to identify model structural errors,
• Analysis and ranking of the information content of data,
• Pragmatic methods for the optimal design of monitoring networks,
• Model reduction techniques and surrogate modelling,
• Model complexity and legitimacy, and
• Bayesian model selection and averaging.

We like to make stochastical modelling and uncertainty analysis assessible for practical use and facilitate the goal-oriented planning of measurement campaigns. Our applications include modelling of water and contaminant flow in coupled river-groundwater systems (braided rivers), soil-plant-systems, and small catchments.

Small catchment areas, for example in the Erzgebirge, react with fast flood runoffs to precipitation of high intensities.
The mechanisms and flow processes that lead to these dynamic catchment reactions are not clearly identified so far, nor is the question, concerning the minimal amount of data for the creation of a reliable operational flood-forecasting model, answered. Similar challenges arise in the forecast of runoff changes in small catchments due to climate change and/or in land use. One integrative research approach includes the development of a hydrologic observation network that connects the construction of research areas and hydrologic modelling. This approach is part of the core research area "hydrologic processes in small and medium sized catchments" at the chair of hydrology (TEAM Catchment Hydrology) and aims to improve predictions and forecast calculations of water balances and extreme events. For that, the junior research team EXTRUSO (extreme events in small and medium sized catchments) amongst others develops innovative methods for process identification, inverse modelling and uncertainty analysis. This happens in close cooperation with the chair of meteorology of the TU Dresden, because of their expert knowledge in analysing and modelling of interactions between land surface and atmosphere, as well as the multitude of observation and experimental stations that are maintained.