Dealing with Multisource Information for Estuarine Flood Risk Appraisal in Two Western European Coastal Areas

Abstract

Estuaries are usually affected by compound flooding triggers that cause diverse territorial damages. While fluvial flood risk assessment frameworks are well established in the literature, integrated management instruments that deal with estuarine flood risk remain incomplete and often lacking. This research presents a methodology to extract relevant information from multiple sources post-event and a database building process that is applied to two contrasting estuaries (the Tagus River estuary in Portugal, and the Shannon River estuary in Ireland) in the Western European coastal area. Overall, a total of 274 documents were analyzed and the information was stored in two databases. Multiple correspondence analysis was applied to extract the most informative and relevant estuarine flood indicators. An integrated estuarine flood risk assessment framework is presented and discussed based on the extracted indicators. The framework is driven by two distinct dimensions (oceanic and hydrographic) and revealed the transversal position of triggers of estuarine floods, reflecting the compounding effects usually present in these areas. The results also highlight two levels of flood risk mostly based on damage typology.