The hydrological conditions are determined or mapped in water catchment areas using rainfall-runoff models. Flows are determined on the basis of long-term simulations or statistical model rain as a function of the return period. The results are used to make statistical statements about the expected floodwater discharge in the water and, for example, Throttle outflow for flood retention basins. The HQ (T) values determined in this way represent input parameters for one-dimensional and two-dimensional water-field calculations.
The rapid development of computing technology has led to the solution of water-building problems by numerical models. Depending on the complexity of the problem to be solved, one-, two- and three-dimensional models are used for the simulation. If, until a few years ago, one-dimensional water level calculations were regarded as state of the art, flow calculations are now carried out using two-dimensional models. When it comes to complicated hydraulic conditions, where the imaging of the vertical speed component is decisive, three-dimensional models are also increasingly used. The processes used in nature, for example currents, were based on differential equations whose simulation is only possible with numerical algorithms. For this purpose, our institute offers flow, material transport and solid transport models.
With the EG Directive on the assessment and management of flood risks, uniform guidelines for flood risk management have been defined for the first time throughout Europe. The aim was to reduce the risks to human health, the environment, cultural assets and economic activity that are subject to high water pollution. The reaction is carried out in a 3-stage process. In the first stage, areas with a significant flood risk had to be defined by 22 December 2011. On this basis, flood hazard and flood risk maps had to be prepared by 22 December 2013. At a third stage of the project, flood risk management plans will be drawn up, which contain targets for the reduction of flood risks and measures to achieve these objectives.