How to Assess the Benefits From Early Flood Warning Systems? (PAP014732)

Código

PAP014732

Autores

Hans Peter Nachtnebel

Tema

Flood forecasting and early warning systems

Resumo

The objective of this paper is to assess the reliability and the efficiency of early flood warning systems (EWS) in small river basins exhibiting short hydrological response times. The reliability expresses the hydrological quality of the forecasts for different lead times. The efficiency evaluates the socio-economic benefits from a forecasting system characterised by the ratio of reduced damages dependent on lead time and the costs of the early warning system. The assessment is performed in two steps: first the reliability of early warning system is evaluated by analysing the performance of an EWS over several years and by considering true and false alarms. Second, the economic effectiveness estimates the potential benefit in form of avoided damages in an event dependent evaluation. The combination of reliability and avoided damages leads to the warning expectation as an indicator for the optimal alert.EWS as a non-structural protection measure induce very low detrimental effects on the natural environment and can be quickly implemented. Here, experiences from an Austrian case study from a pre-alpine catchment are described demonstrating the application of the proposed methodology.