Long-Term Design of Mangrove Landfills as an Effective Tide Attenuator under Relative Sea-Level Rise

Abstract

A mangrove ecosystem is an important option in Ecosystem based Disaster Risk Reduction (Eco-DRR). The effectiveness of an artificial mangrove landfill in reducing tidal amplitudes was studied by performing a coupled numerical model that simulated wave propagation and soil consolidation. The constructed model simulated the propagation of tide over an artificial landfill that was subjected to land subsidence, sea-level rise, vegetation growth, and sediment deposition. A case study analysis confirmed that the tidal amplitudes are reduced if the initial elevation of the landfill is appropriately considered to achieve an equilibrium state of the landfill over its lifetime. Sediment deposition may be the only dependable source to sustain the surface elevation of a mangrove with relative sea-level rise. Sediment deposition is important to promote vegetation growth, which in turn contributes to sedimentation by enhancing a tranquil hydrodynamic environment. An insufficient initial elevation of the landfill will result in less effective protection against tidal propagation after it substantially subsides.

Surface elevation changes in an estuarine mangrove forest in Vanga, Kenya: Implications for management and mitigation of sea-level rise

“…Most management and conservation strategies, including restoration, especially for mangroves, have hitherto focused on the ecological aspects but minimally on sediments which is one of the critical pillars for their success. To mitigate the effects of SLR, artificial embankments and interventions to complement nature-based adaptation and resilience have been suggested (Takagi, 2018;Dasgupta et al, 2019). These artificial embankments are intended to increase the efficiency of tidal damping and velocity attenuation and optimize the mangrove functionality of sediment trapping and consolidation.…”

Velocity Dissipation Approach on Drag Analysis using CFD for Shoreline Defense

“…These natural defenses are attractive because they are costeffective solutions that provide multiple benefits, contributing to the community and ecological resilience [26]. The unique architecture of this ecological system makes it capable of absorbing the hydrodynamic turbulence and keeping the function and structure of the ecosystem [28] and attenuating the energy of tsunamis, cyclones and storm surge reducing velocity on channel floodplain [25].…”

Community-Based Portable Reefs to Promote Mangrove Vegetation Growth: Bridging between Ecological and Engineering Principles

“…Mangroves work as a barrier, leading to changes in flow direction resulting in vegetative surface friction, inducing wave energy dissipation and damping [ 10 ]. The advantages of mangrove forests are referred to as “ecological resilience” for their ability to absorb hydrodynamic disturbance [ 11 ]. Mangroves are also considered to be a green infrastructure that contributes to disaster prevention through flood regulation, erosion control, sediment trapping, nutrient recycling, wildlife habitat, and nurseries [ 1 , 12 , 13 , 14 , 15 , 16 ].…”

“…In addition to these global initiatives, scientific communities are trying to develop new ideas for protecting coastal areas from coastal hazards by incorporating the mangrove ecosystem for ecological disaster risk reduction (Eco-DRR). Eco-DRR is an effort composed of the restoration, conservation, and sustainable management of ecosystems to reduce the risk of disaster [ 11 ]. The idea of rehabilitating mangroves on a hybrid raised platform proposed recently [ 12 ] is expected to lead to new strategies for disaster risk reduction.…”