Publikationsserver der RWTH Aachen University
Über die gekoppelte 1D- und 2D-Modellierung von Fließgewässern und Überflutungsflächen
Abstract
dc:descriptionExperiences from recent flooding events dramatically illustrated limitations of existing flood protection and pointed toward the necessity for more sophisticated preventive technology. To date the design flood concept does not offer comprehensive protection. With growing size of critical river sections and the subsequent need to document the effectiveness of protective measures and possibly resulting damage, required time and costs for each simulated variable rise significantly. Demands for more efficient computational solutions fulfilling the complex requirements of the flood protection exist. Algorithms developed in the late 20th century on basis of the Reynolds equations are only limited suitable to consider all aspects of flood protection. Within limits of one-dimensional models additional assumptions (e.g. the neglect of local acceleration in relation to the gravitation) were applied, to simulate the typical characteristics of flood events (long periods and large spatial expansion) in times of insufficient computation capacity. However, one dimensional models fail as predictive tool, when flooding beyond river banks is considered. To day two-dimensional models are still too complex and generally not applicable for near real-time mathematical simulations. An alternative solution is presented in this thesis. One- and two-dimensional approaches are combined to an effective flood protection simulation system. Any forecasting of the impacts of floods has to balance accuracy and efficiency. The complexity of models available today ranges from simply intersecting a plane representing the water surface with a Digital Elevation Model up to the full solutions of the Navier-Stokes equations. Techniques that apply two-dimensional, depth-averaged solutions of the Navier-Stokes equations increase computational time and costs and are generally not realistically applicable for near real-time purposes. However, the sophistication of flood inundation modelling has increased in parallel with model developments and increased computational resources. However, it remains an open question, if simpler more cost and time efficient models provide similar levels of predictive accuracy. Hybrid models change handling characteristics due to the scale problem and the difficulties of analyzing extreme flood events in large catchment areas. The simplification into a one- and two-dimensional simulation section increases the efficiency of the whole model, such that complex systems can be examined more rapidly and in greater detail. Coupled 1D-2D models permit high scenario numbers. They extend the possible application of modern, risk-oriented flood forecasting and prevention efforts. Apart from the coupling of different partial models to an overall integrated system, the presented method uses consistent simplifications of the flow equations out (diffusive wave theory).
Degree
thesis:*- Grantor dc:publisher
- Publikationsserver der RWTH Aachen University
- Year dc:date
- 2009
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Kamrath, Paul
- Contributors dc:contributor
-
- Köngeter, Jürgen
Subjects
dc:subject × 15Rights
dc:rights- Statement dc:rights
-
- info:eu-repo/semantics/openAccess
- Language dc:language
- ger