Improved soil quality

The Orbital Forest of Tirana is an innovative urban forest that as a green belt forms a natural growth boundary for the City. Tirana has experienced rapid development in the past decades that led to population growth challenging municipal services and infrastructure, while climate change also posed extensive pressures to the urban area with intense flooding, precipitation, urban heat and degrading environment (1, 4). The Orbital Forest is a ring on the periphery of the City that connects 14,000 ha of Tirana’s parks, agricultural fields, and forests, maintaining the ecosystem and supporting biodiversity. (3, 4) The NBS aims to increase urban greenery through the plantation of 2 million trees that fit well to the existing ecosystem while also creating a natural boundary to halt urban sprawl (1,4,5). The afforestation of the Orbital Forest has been done through the “Donate a Tree For Tirana” campaign started in 2017 where citizens, businesses and international organisations can plant a tree adding to the green belt. As of 2021, more than 440,700 trees in the framework of the "Donate a Tree" campaign are also bringing urban nature closer to residents (3).

Kaysone experiences severe flooding events on an annual basis due to its location to the banks of Mekong river, as well as periodic storms, and past responses to these threats have focused on the Savanxay Market and the Southern Flood Gate, but with limited success (Ref. 1). This intervention focuses on the development of an integrated adaptation plan for the area around the market and adjacent to the Mekong canal. This plan includes NBS-specific components considering how the market's parking area provides an important opportunity for bioengineering and green cover, and that there is "an opportunity to use adjoining land as a constructed wetland and park for recreation, flood retention and storm water treatment" (Ref. 1). The adaptation plan comprises seven points overall, focusing on wastewater recycling, walking paths, proper drainage and green space in addition to an educational component related to climate change and its impacts (Ref. 1).

Mauritius is a biodiversity hotspot, which has been declared by IUCN as a “Centre of Plant Diversity”. 39% of plants, 80% of non-marine birds, 80% of reptiles, and 40% of bat species on the islands are reported as endemic. (4) Nevertheless, human activity keeps threatening this endemicity in Port Louis, a port city and the capital of Mauritius. The city is surrounded by a semicircle of mountains on one side and the Indian Ocean on the other. In 2006 a local NGO started implementing an initiative that focused on restoring native vegetation to the hill that harbours the capital and it's also the place of an important historical heritage, the Fort Adelaide. (2)

The redevelopment of the Bishan-Ang Mo Kio Park (Singapore) saw the naturalisation of the previously channelised Kallang River, as well as the installation of wetland cells as water cleansing biotopes and creation of butterfly habitats (Ref. 1).

The Kallang River was previously confined to a concrete canal that ran to the southern edges of Bishan-Ang Mo Kio Park (Ref. 1). The channel segregated the two residential areas situated on either side of the park, with the river's 2.7km continuous concrete channel being crossable at only certain defined points (Ref. 3). Following its naturalisation, culminating in 2012, the now 3.2km meandering river is considered the park's highlight, "merg[ing] seamlessly with the park's greenery" (Refs. 1 & 6), and creating a "blue-green recreational network which is well-integrated with nearby residential areas" (Ref. 2).

In November 2019 the municipality of Hammam Sousse alongside one of the local schools initiated a climate intervention by planting trees next to the banks of the river Oued El Hammam. The municipality of Hammam Sousse is located in the central-eastern part of Tunisia (Sahel region), and as a coastal city, it enjoys a warm Mediterranean climate with a dry summer. The Mediterranean region is ranked among the regions which are the most vulnerable to the effects of climate change and the intervention focused on implementing solutions to mitigate these effects. (1,2)

Xalapa is located beneath towering volcanic peaks in the Sierra Madre Oriental, and the city is crossed by at least five minor streams, seven rivers, and it has four man-made lakes and one lagoon in its territory. Its natural ecosystem represents “1% of the national forest area and hosts more than 12% of forest biodiversity” [1]. However, unplanned expansion has resulted in deforestation and the inadequate management of its waterways. In addition, forests, riparian corridors and wetlands have been cleared for agriculture and urban infrastructure. These disruptions to the environment have increased the frequency and intensity of flooding in the city [2]. To meet the environmental challenges, the United Nations Environment Programme (UNEP) and Mexico's Secretariat of Environment and Natural Resources-SEMARNAT launched an initiative as part of UNEP's multi-city CityAdapt Project, backed by the Global Environment Facility (GEF) [3]. The project focuses on four interventions to improve resilience to climate change through NbS: 1) riparian restoration along the Papas urban river; 2) ecological restoration of the Estropajo Hill; 3) installation of rainwater systems within the most vulnerable areas in Xalapa; and 4) implementation of an artificial wetland at schools [2,4].

The green belt was created not only as an aesthetic element but also to serve as the lungs of the city. The forest planting works around Nur-Sultan have been carried out since 1997 [6, 7]. The area of ​​the green belt of Nur-Sultan is 100 thousand hectares, of which 15 thousand hectares are planted within the city limits. The main idea of the project was to provide comfortable conditions for the residents of Nur-Sultan city, which would serve as a mechanism for improving air quality, mitigating climate and as a natural barrier to protect the city from dust winds and snowstorms [2, 4, 5, 6, 7]. An important aspect that was taken into consideration are the animal species of the forest, as the territory of the green belt is inhabited by foxes, hares, corsacs, white and grey partridges, roe deer, wild boars, etc [1, 2, 7, 8]. The primary importance of biodiversity efforts is assigned to the breeding of birds, especially pheasants [1, 2, 3, 4, 5], as pheasants are an element of local cultural heritage, and on the territory of the green belt, traditions and cultural events related with the pheasants are organised every year [2, 4]. The young forest should turn into an improved recreation area, a favourite pastime for city residents at any time of the year [2,7].

Thammasat Urban Rooftop Farm (TURF) is Asia's largest organic rooftop farm, which unites principles of modern landscape design with traditional agriculture of rice terraces, to transform wasted space into productive land. By mimicking traditional rice terraces, Thammasat University Urban Farming Green Roof has become an all-in-one solution–as a public green space, urban organic food source, water management system, energy house, and outdoor classroom–which serves as an adaptation model for anticipated climate impacts that can be implemented and developed across Thailand and Southeast Asia. Additionally, the mountain-shaped Thammasat University Green Roof utilizes its vast space as an infinite source of clean energy, not only in terms of organic food but also solar power for the community. [1, 2, 3]

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 Nyashishi wetland is located on the western side of Lake Victoria some 15 km from Mwanza, a port city of the lake. The area is characterized by a double maxima rainfall, with heavy rains occurring during October to December. The wetland is traversed by the Nyashishi River, which is an intermittent river draining stormy waters and domestic waste water into Lake Victoria. Increased human socio-economic activities in Mwanza, such as horticulture, overgrazing and discharge of industrial effluents, have degraded the Nyashishi wetland. As a result, vegetation specifically elephantiasis and papyrus that used to flourish in the wetland and provide fish breeding grounds have disappeared. The crocodiles, large lizards and a host of other creatures that used to populate those areas cannot be seen today. Since the wetland and the river are part of the Lake Victoria Basin, both have been subjected to floods and droughts, impacting livelihoods, public health and the environment. The root causes of floods are irregular seasonal and year to year variability in rainfall patterns, combined with mismanagement of land and water resources, leading to soil erosion and increased run-off. Therefore restoration efforts in the area are much needed. (1, 5)