Planning for a future on dynamic Islands in the Maldives: a description and analysis of key nearshore processes on Dhigurah Island

Abstract

Low-lying atoll states are commonly portrayed as the most vulnerable to the impacts of sea-level rise. However, many studies now contradict this notion by showing atoll islands to be dynamic morphological landforms that adjust their shape, size and position in response to changes in boundary conditions. A common response to shoreline instability and the needs of the tourist industry has been to construct hardengineering structures, which degrade natural habitat and undermine the inherent ability of islands to adapt to environmental changes. Coastal infrastructure is known to constrain nearshore processes and yet it is often designed without information on, or proper consideration of, its effect on nearshore processes. If island communities are to allow their islands to be dynamic and to live with natural nearshore processes, they need a better site-specific understanding of these processes. To address part of this gap in understanding, this study examines two key nearshore processes on Dhigurah Island, the Maldives – sediment supply and seagrass. It finds that there is an active sediment supply of Halimeda and coralline red algae from the inner reef flat to the oceanward shoreline. It also concludes that seagrass beds are significantly higher than surrounding substrates and they provide important coastal protection. With understanding of these processes, island planners will be able to protect and incorporate them in any future development of coastal infrastructure. This study also carries wider significance, as Dhigurah Island is representative of many islands in the Maldives that are beginning to embrace tourism. Current provisions for planners to gain understanding of the nearshore processes on all the islands in the Maldives expecting development are deficient. Therefore, this study presents the principles behind, and the scope of, a rapid study that could be conducted on any island within a reasonable timescale. Through community ownership of this rapid study and lifelong learning, communities will be able develop an understanding of nearshore processes. This will give them the skill and motivation to work with the natural processes by which their islands adapt to environmental changes.