R&D highlights edition 2019

Flood risk 7 R&D Highlights 2019 p Beach at Pantufo with local fishermen’s boats Topographic survey at Praia Abade Aerial view of coastal community at Praia Abade (Príncipe) (CDR International) D eltares and CDR International (in a sub-consultant role) are working together in close cooperation with MOPIRNA (Ministry of Public Works, Infrastructures, Natural Resources and Environment) and local communities to quantify coastal hazards, risks and adaptation options at eight locations in São Tomé and Príncipe. The Islands of São Tomé and Príncipe São Tomé and Príncipe is a Small Island Developing State (SIDS) in the Gulf of Guinea, in West Africa. The country gained independence from Portugal in 1975. Since then, many workers from former plantations have migrated towards the coast to work as fishermen. Coastal communities have been growing rapidly without proper spatial planning, occupying areas exposed to a high risk of natural hazards and the adverse consequences of climate change. Natural hazards and climate change The main natural hazards affecting the coastal communities are coastal flooding due to extreme storm surges and waves, river flooding, high winds, beach loss, and flash flooding and overland flows from intense rainfall. Climate change and sea level rise will exacerbate most of these hazards. The state-of-the-art numerical models Delft3D, XBeach and SFINCS were deployed to assess the various hazards and climate change scenarios and the effectiveness of possible adaptation measures. Hazards were stated as risks and damage affecting the local communities using the Delft-FIAT tool. Social assessment, participatory risk mapping, and soft solutions The study involved eight coastal communities: Iô Grande, Praia Melão, Pantufo, Praia Lochinga-Gambôa-Cruz, Micoló and Praia Abade. Particular attention was paid to the most vulnerable communities and sub-groups in order to establish a comprehensive understanding of local issues, opinions, and possible adaptation options. Stakeholder participation – involving interviews and participatory risk mapping sessions in each community – was an essential component of the study. The findings were used in tandemwith the technical study to recommend adaptation options. Where possible, “soft” measures were proposed rather than conventional “hard” structural measures: beach restoration, revege­ tation, construction of canoe shelters, and raising community awareness Contact Alessio Giardino, Alessio.Giardino@deltares.nl t +31 (0)6 1582 1874 Nena Vandebroek, Nena.VandeBroek@deltares.nl t +31 (0)6 8317 3315 Luisa Torres ,Luisa.TorresDuenas@deltares.nl t +31 (0)6 2118 4824 Further reading https://www.deltares.nl/en/news/adaptation- climate-change-sao-tome-principe/ The combined effects of high exposure to natural hazards and deficiencies in spatial planning and the enforcement of existing regulations make the islands of São Tomé and Príncipe extremely vulnerable to the impacts of extreme events and climate change. Multi-hazard risk assessments conducted in close collaboration with local communities in scarce data environments are useful to analyse adaptation options and increase climate resilience. COLLABORATIVE RISKMAPPING AND CLIMATE ADAPTATION IN SÃO TOMÉ AND PRÍNCIPE