Coastal protection / hazard mitigation

Quelimane is a port city in Mozambique. It lies below sea level right alongside the Good Signs river (Rio Bons Sinais), and just a few kilometres from the coast. The frequent extreme weather phenomena such as rain and marine flooding render the city extremely vulnerable to climate risks. In 2013, the municipality concluded that one solution involves restoring large areas of mangroves, which act as a nature-based solution against flooding, helping to stem the tide by preventing soil erosion. In the past mangroves were cut down by the locals for building and cooking but now with the help of the municipality and local communities, the trees are restored and used as the first line of defence against climate change (1).

A combination of green and grey coastal infrastructure is being developed off the coast of Semarang, Indonesia in response to the increased risk of coastal flooding as a result of sea-level rise (Ref. 1). Due to its geography as a coastal city, "Semarang deals with various physical challenges...such as tidal flooding, erosion, land subsidence and rising sea levels" (Ref. 1). Tidal flooding is becoming increasingly worse as a result of climate-induced sea-level rise and increasingly extreme weather events (Ref. 1 and 3). Coastal protection which was historically afforded by naturally occurring mangrove systems has been reduced as a result of the mangroves being largely lost to urbanisation, fish farming and other forms of agriculture (Ref. 2). One proposed sub-project of the Integrated Protective Coastal Zone, Coastal Balance Project 01: Coastal Balance Pilot in Genuk/Sayung, will focus on the northeast of Semarang. Using the 'Building with Nature' approach, it will leverage nature-based solutions through the deployment of green infrastructure, primarily focusing on mangrove restoration (Ref. 3). Mangrove restoration is hoped to stabilise the coastline, therein reducing erosion, encouraging sedimentation and increasing resilience against sea-level rise (Ref. 3).

The revitalization and conservation of the Butuah Wetlands work started in 2020 by a Ghanian NGO, called Friends of the Nations, in collaboration with some public institutions and an American charitable foundation that makes small grants to grassroots environmental causes around the world. In the past, the wetland has been a major flood reservoir that channelled excess water from different parts of the metropolis into the sea as well as a beacon of biodiversity. The weak monitoring regime of this wetland has led to massive encroachments by both private and industrial developers, therefore, causing biodiversity depletion and contributing negatively to climate change. (1)

The Recreio green corridor project, launched in 2012 by the Municipal Secretariat for the Environment and several city departments, aims to protect and enhance the rich biodiversity and ecosystems of the area, to help with the resilience and adaptation of the west side of the city, an area affected by coastal flooding and erosion. The project mostly focused on preserving, connecting, and expanding the existing local urban nature elements and protecting their ecology. Lastly, the project also aimed to educate the residents about native vegetation and help build social interaction and cohesion between the local communities [Ref 1]. The project was designed to preserve and connect 320.76 ha of protected areas and add 60.73 ha of open public spaces and squares. And in total, the corridor has a linear extension of close to 8 kilometers, passing through very diverse urban areas (Ref. 7), including natural parks, a lagoon system, water canals, and social housing areas.

The Barr Foundation started the cross-cutting program called Waterfront Initiative to support the sustainable planning and accessibility of the waterfront area while also increasing residents awareness and environmental stewardship of the waterfront. The Waterfront Initiative initially supported organizations in harbour planning, designing waterfront parks, and climate resilience efforts along the Boston waterfront. In 2018, it has also strengthened its focus on social equity and public engagement across more vulnerable neighbourhoods around waterfront issues (1,2)

Parc Marianne is an ecodistrict that aims to address multiple challenges such as climate action for adaptation, environmental quality, flooding, and in response to the high population growth in Montpellier. Parc Marianne is connected to public transportation, has bicycle lanes and car parks, and the sidewalk is shared between pedestrians and bicyclists and structured with trees and other greenery. The park was certified with the ecodistrict label in 2015 following requirements like environmental sustainability, thermal performance, quality of life, nature and biodiversity, and mobility (Ref. 1). Parc Marianne is a mixed neighbourhood with an ability to combine city and nature, quality of life and centrality (Ref. 2).

The Gorla Maggiore water park, inaugurated in March 2013, is situated within the municipality of Gorla Maggiore, in the Italian region Lombardy, located about 30 kilometers northwest of Milan. The water park is a constructed wetlands (CW) built on the banks of the Olona river that includes (a) a pollutant removal area composed of a grid, a sedimentation tank and four vertical sub-surface flow constructed wetlands; (b) a multipurpose area with a surface flow constructed wetland or pond with multiple roles; and (c) a recreational park with restored riparian trees, green open space, walking and cycling paths. [1]

The Sea's Corridor is a project that created green spaces with good quality that act as green belts of the city while serving as a support for the sustainable and not motorized means of transport. It was part of a project Plan called "Plan E" of the Municipality of Palma (Ref 1). The project was completed and in 2020 there are plans to do some renovations. They want to join the Sea's Corridor to Platja de Palma, as well as create new green spaces with a wider link with the ocean (Ref 5).

Milton Common is the second stage of the multi-million-pound Flooding and Coastal Erosion Risk Management scheme being developed across the north of Portsea Island, from Mountbatten Centre round to Milton Common. The overall project will reduce the risk of coastal flooding and erosion and provide the critical infrastructure the city will need over the next 100 years (6).
As the second phase, Milton Common included the instalment of a new rock revetment as a plans defence, the creation of a coastal path and three new earth bunds with new footpaths (6). The work has also included the demolition of Great Salterns Quay and restoration of the natural mudflat habitat (2,4).
The fully completed scheme will significantly reduce the risk of coastal flooding to Milton Common and the local area over the next 100 years; it will offer protection against a 1 in 500-year flood event providing one of the highest standards of flood protection in the UK outside of London (6).

This project is studying seagrass to learn more about the distribution and health of seagrass in the waters of the Solent. By learning about where seagrass exists it can be better protected. The Wildlife Trust have been visiting local seagrass sites including the harbour in Portsmouth (1). Measures that can be employed to help protect Zostera beds include Boat mooring management - a program of awareness to relieve pressure on seagrass in areas of high boating activity, such as the Solent (3) and restoration through seeding or transplanting seagrass and Improving habitat conditions to encourage natural regeneration and colonisation (3).