Systemic flood risk management: The challenge of accounting for hydraulic interactions

Ciullo, A.; De Bruijn, Karin M.; Kwakkel, J.H.; Klijn, F.

doi:10.3390/w11122530

Systemic flood risk management

Title

Systemic flood risk management: The challenge of accounting for hydraulic interactions

Author

Ciullo, A. (TU Delft Policy Analysis; Deltares)
De Bruijn, Karin M. (Deltares)
Kwakkel, J.H. (TU Delft Policy Analysis)
Klijn, F. (TU Delft Policy Analysis; Deltares)

Date

2019

Abstract

Rivers typically flow through multiple flood-protected areas which are clearly interconnected, as risk reduction measures taken at one area, e.g. heightening dikes or building flood storage areas, affect risk elsewhere. We call these interconnections 'hydraulic interactions'. The current approach to flood risk management, however, neglects hydraulic interactions for two reasons: They are uncertain and, furthermore, considering them would require the design of policies not only striving for risk reduction, but also accounting for risk transfers across flood-protected areas. In the present paper, we compare the performance of policies identified according to the current approach with those of two alternative formulations: One acknowledging hydraulic interactions and the other also including an additional decision criterion to account for equity in risk distribution across flood-protected areas. Optimal policies are first identified under deterministic hydraulic interactions, and, next, they are stress-tested under uncertainty. We found that the current approach leads to a false sense of equal risk distribution. It does, however, perform efficiently when a risk-averse approach towards uncertain hydraulic interactions is taken. Accounting for hydraulic interactions in the design of policies, instead, increases efficiency and both efficiency and equity when hydraulic interactions are considered deterministically and as uncertain, respectively.

Subject

Equity
Flood risk management
Uncertain hydraulic interactions

To reference this document use:

http://resolver.tudelft.nl/uuid:70c5fbe5-51c8-4d1c-8ec0-59ea27b9b939

DOI

https://doi.org/10.3390/w11122530

ISSN

2073-4441

Source

Water, 11 (12)

Part of collection

Institutional Repository