Collection of monitoring data at specific time intervals during the project to aid evaluation

Since 2008, the City of Portland, Oregon has used various policies and programming to encourage the use of eco-roofs (vegetated roofs) throughout the city to address stormwater management (Ref. 2,3,4). In addition to stormwater management, eco-roofs have the benefits of: saving energy, reducing pollution and erosion in waterways, preserving fish habitats, creating new habitats for birds and insects, absorbing carbon dioxide, cooling urban heat islands, filtering air pollutants, and providing urban green space (Ref. 1,5). From 2008 to 2012, the City of Portland used the Ecoroof Incentive program to encourage property owners and developers to construct ecoroofs (Ref. 4,5,12). In 2018, the City of Portland adopted a mandate for ecoroofs in new buildings (Ref. 2,3,12). These policies and programs led to a growing interest in the use of ecoroofs, and resulted in the construction of over 130 ecoroofs (Ref. 3,4,11).

The Cheonggyecheon Stream Restoration Project saw the dismantling and removal of an elevated freeway and the uncovering of a 5.84km section of the Cheonggyecheon historic stream in the centre of Seoul, South Korea (Ref. 2). One of the world’s largest and most densely populated cities, the revitalisation of the Cheonggyecheon Stream has provided Seoul with an ecologically sensitive green pedestrian corridor in an area that was previously recognised as being congested, overpopulated and polluted (Ref. 4). The restoration has provided environmental, social and economic benefits within its immediate proximity (Ref. 2). In addition to becoming a "vehicle for revitalisation, urban renewal and economic development", it has "also signified a shift in Korean planning priorities", with both city authorities and residents now placing an emphasis "on health, sustainability and social responsibility" (Ref. 4). It has further "become a template for planning intention and action across South Korea" (Ref. 4).

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)

In 2015 an innovative project called the "Sweet City" (Ciudad Dulce) was launched in Curridabat. Its main goal was to bring wild spaces into 21 urban neighbourhoods of Curridabat ("spaces of sweetness") and eight corridors ("transitions") and thus linking neighbourhoods and parks through a participatory re-design approach with local stakeholders [3]. The main objective of the Sweet City model is to reintroduce biodiversity into the urban space by focusing on five fundamental dimensions: Biodiversity, Infrastructure, Habitat, Co-existence and Productivity. The interventions of this project included park improvements, sustainable drainage systems, the protection of wetlands, spring water recovery, promoting organic farming practices, and many strategies that help improve biodiversity and motivate citizen participation, finally, as ecosystem-based disaster risk reduction measures and climate change adaptation actions [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.

This project started as a grassroots movement by Hunter’s Bar Infant School (HBIS) in Sheffield when they were seeking to actively help to protect children from air pollution. HBIS led a fundraising campaign that, in collaboration with the University of Sheffield, provided the base to create a green barrier in their playground. The NBS is part of a bigger study called BREATHE that provides the science behind the project, which involves the design of the green barrier, the assessment of its impacts and a feasibility evaluation for installing green barriers in other schools in Sheffield and in Buenos Aires. (1)

The field is a 3.5 hectare of grassland, grazed by horses for over 20 years. After it fell vacant in early 2011, a group of local residents (“The Field Group”) negotiated a community lease with its owners, City of Edinburgh Council, with the aims of creating an orchard, creating/restoring semi-natural habitats and encouraging its use for quiet recreation and informal education. Members can volunteer their gardening labour or donate money. They can then participate in a garden run for the community – whether to pick the vegetables, learn fruit-growing, help to keep the chickens or just enjoy the space. [ref 1, 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 Stavros Niarchos Foundation Cultural Center (SNFCC) is a project finalised in 2016 and “handed over” through a public/private partnership scheme, from the foundation/donor to the Greek state. The site hosts the National Library of Greece and the Greek National Opera in a 170,000 sq m landscaped park. The SNFCC's objective is to restore Greece's image and become a global role model of environmental sustainability. The project is committed to a range of educational and cultural activities, which have been provided for free. It also claims flood-regulating functions, air quality improvement impacts and shade provision, among others. [1]

The project is a close-to-nature maintenance concept that combines the diverse usage requirements in public green spaces and the promotion of biological diversity through near-natural care. (Reference 1) It aims to promote biodiversity in the area through the plantings of local trees, installation of deadwood stacks, dry stone walls and boulders, which will help in the increased interconnectedness of the green areas and provide for structured habitat for the local species. The initiative also involves development of ecological standards for the handling of green spaces in the country, such as natural care practices that will protect local biodiversity (e.g. adapted mowing regime for lawns, flower meadows). (Reference 1, 2)
The "Urban green - species-rich and diverse" project is a cooperation project of the alliance "Municipalities for Biological Diversity eV" (Alliance) and the German Environmental Aid eV and with the participation of the five partner municipalities Frankfurt am Main, Hanover, Wernigerode, Kirchhain and Neu- Response. The project is funded in the Federal Biodiversity Program by the Federal Agency for Nature Conservation with funds from the Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety. The experiences and results of the pilot project are further incorporated into the maintenance requirements for public green spaces in the urban area in other municipalities (Reference 1, 7).