Land raising as a solution to sea-level rise: an analysis of coastal flooding on an artificial island in the Maldives

The Maldives (land elevation approximately 1m above mean sea-level) is often associated with the threat of rising sea-levels. Land scarcity due to population pressure is also a major issue. In the late 1990s a new 1.9km2 2m high artificial island, Hulhumalé was created for urban expansion, including an allowance for sea-level rise. This paper assesses flood exposure through an extreme water level scenario on Hulhumalé taking into account sea-level rise and analyses potential adaptation options to extend island life. Results indicate that overtopping is likely to occur with 0.6±0.2m of SLR, with more severe, widespread flooding with 0.9±0.2m of sea-level rise. If the Paris Agreement goals are met, flooding is not anticipated this century, but under a non-mitigation scenario, flooding could occur by the 2090s. Building seawalls 0.5m, 1.0m and 1.5m high could delay flooding for 0.2m, 0.4m and 0.6m of sea-level rise, respectively. Land raising has been successful in Hulhumalé in reducing flood risk simultaneous to addressing development needs. Whilst new land claim and raising can be cost-effective, raising developed land provides greater challenges, such as timeliness with respect to infrastructure design lives or financial costs. Thus the transferability and long-term benefits of land raising requires further consideration

Flooding ecology of voles, mice and shrews: the importance of geomorphological and vegetational heterogeneity in river floodplains

Contains fulltext : 32511.pdf (publisher's version ) (Closed access)Since voles, mice and shrews are important animals in food chains of river floodplains, there is a need for data on their spatial and temporal distribution in periodically flooded areas. During a live trapping study between two successive floods in an embanked river floodplain, the ’Afferdensche en Deestsche Waarden (ADW)’, six species were frequently observed, viz,Microtus arvalis (Pallas, 1778),Clethrionomys glareolus (Schreber, 1780),Sorex araneus (Linnaeus, 1758),Crocidura russula (Hermann, 1780),Micromys minutus (Pallas, 1771) andApodemus sylvaticus (Linnaeus, 1758). Ungrazed rough herbaceous vegetation appeared to be rich in numbers and species, whereas no spoors of small mammals were observed in large parts of the ADW floodplain (eg bare substrates and maize fields). Vegetation structure seemed to be very important in guiding the recolonisation process after flood events. Throughout the year the highest numbers of small mammals were captured on and near the non-flooded elevated parts functioning as refugia during inundation. Poor habitat connectivity, sparseness of non-flooded recolonisation sources and small numbers of survivors led to slow recolonisation. The time between two successive floods (eight months) was not long enough for entire recolonisation of ADW. Small mammal densities at more than 30 m from the non-flooded areas were always lower than in non-flooded areas