Reducing the Vulnerability of Societies to Water Related Risks at the Basin Scale (Proceedings of the third International Symposium on Integrated Water Resources Management, Bochum, Germany, September 2006). IAHS Publ. 317, 2007, 342–346.

Automatic optimization offers new possibilities for cost-effective flood protection at urban rivers

LUTZ FELDMANN¹ & JENS SCHRAMM²

1 Ingenieurbüro Feldmann GmbH, Talstraße 12, D-51588 Nümbrecht, Germany

info@ib-feldmann.de

2 DDC Dorsch Consult Ingenieurgesellschaft mbH, Löscherstraße 16, D-01309 Dresden, Germany

Abstract Flood protection is a major expense, and therefore a burden on public budgets which requires that financial resources are applied most efficiently. Designing large-scale flood protection for urban rivers is a com­plex task with many constraints, which makes finding economical solutions time-consuming and therefore costly. This paper introduces a planning tool which computes the most cost-efficient solution for a defined extent of flood protection. The automatic optimization process is controlled by evolutionary strategies. It is shown that, compared to manually designed solutions, the optimization system helps to reduce costs for flood protection by up to 20%. Furthermore, this approach allows a detailed analysis of applied boundary conditions such as discharge and freeboard. The sensitivity of these boundary conditions on flood-protection costs can be determined, which is vital for efficiently applying financial resources.

Key words automatic optimization; cost functions; evolutionary strategies; financial resources; flood protection; river