The consequences of flood events can be severe. Flood defences, such as embankments, reduce flood risk by lowering the probability of flooding. Substantial investment in maintenance activities is often necessary to maintain a high level of performance. When embankments deteriorate their likelihood of failure and associated breaching increases.
Within the UK, the flood risk analysis methods that are used, (Gouldby et al, 2008) incorporate the likelihood of failure and associated breaching. The existing methods are however, limited in terms of the physical representation of the breaching process. Any error in predicting breach formation translates to an error in predicting the risk of flooding of downstream areas. To solve this problem HR Wallingford has developed a new breaching model, AREBA (A Rapid Embankment Breach Assessment). AREBA simulates the process of breaching within embankments. It incorporates the effects of a grass cover on the flood hydrograph shape, and calculates a flood hydrograph for surface erosion, headcut erosion or piping failures.
AREBA has been successfully benchmarked against other breaching models (HR BREACH) and also validated full scale and laboratory physical model experiments (EU-IMPACT and USDA-ARS). AREBA is exceptionally computationally efficient and has been designed specifically for use in probabilistic flood risk analysis models that require the impact of multiple breach scenarios to be evaluated.
|Authors||Myron van Damme, Mark Morris, Mohamed Hassan, Paul Samuels, Ben Gouldby|
|Keywords||breach, rapid assessment, embankments, flood risk|
Gouldby BP, Sayers P, Mulet-Marti J, Hassan M, Benwell D (2008). A Methodology for Regional Scale Flood Risk Assessment, Proc. Inst. Civ. Eng Wat. Man., Volume 161, Issue WM3, June
Image courtesy Statkraft Groner.