Green densification model

The Jerusalem Forest is located southwest of Jerusalem and is the green lung of the residents of Israel's capital. The forest has a variety of trees, flowers and wildlife, remains of ancient farming implements and burial caves (2). The forest was planted in the 1950s in an attempt to increase the green cover and natural biodiversity of the area. However, due to intensive urban development including road constructions and energy grid installation and forest fires the size of the forest has been shrinking once covering 4 700 000 m2 to the current size of 1 250 000m2. In 2016, a non-governmental green organisation initiated the renewing of the Jerusalem Forest with the aim to preserve the forest, halt its decrease, secure its sustainable maintenance while involving the public in the conservation efforts increasing their environmental knowledge about their local habitat and support nature stewardship through the application of a community forest model. (1,2,8)

The Anderson Road Quarry, once a vacant 40-hectare site is getting transformed into a sustainable residential neighbourhood while ensuring climate resiliency and low environmental impact in Hong Kong. The site will supply housing for 25,000 people. In addition to this, the city is employing a wide array of adaptive and resilient approaches including saving around 3,000 metric tons of CO2 annually, helping the city live up to its 65% to 75% carbon reduction goal by 2030 set in Hong Kong Climate Action Plan. [1]

Located in the heart of Hung Phu, a new urban area within Can Tho, K-Villa+ has been designed to "mak[e] the most of open and harmonious space[s] with nature, using green design solutions to improve bioclimatic comfort for users, while respecting sustainable values ​​and being friendly to the living environment" (Ref. 5). The low construction density of the building project has been coupled with prioritisation and installation of green areas both on the building itself and in the surrounding ground; permeable coverings to increase water percolation, and landscaping with native and climate-adapted trees and plants (Refs. 1 & 5.) An ecological pond has further been included in the landscaping of the villa's grounds and a rainwater harvesting system has been installed (Ref. 3). Through the application of these green design solutions, the urban heat island is considered to be reduced and bioclimate improved for those within the building, and biodiversity promoted through the planting of a variety of native species (Refs. 1, 2, 3 & 5).

Note that due to a lack of data, the exact point location of the villa is not depicted in the map below, but rather the new urban district, Hung Phu, in which the villa sits.

As of 2011, Windhoek, the capital of Namibia, has a population of approx. 330,000 people. By 2018, an estimated 40% of Namibia’s 2.4 million population were living in shacks and Windhoek makes no exception. Approximately 30% of the capital population lives in unplanned informal settlements struggling to access basic services such as water and sanitation. Worse than that informal settlements are especially vulnerable to environmental hazards: they are squeezed in next to each other on the slopes of mountainsides. When there's the occurrence of floods, they do so with such force and wash away people’s homes and their belongings. Even more distressing, people often lose their children due to rapid and unannounced flash floods. As a response to these threats and challenges the inhabitants of an informal settlement, Onyika (located in Okuryangava - which is a suburb of Windhoek, situated in the north of the capital city) paired with local authorities, donors and climate change experts to embark on a community-led process of creating a climate-resilient community. Being especially vulnerable to climate change, these forms of settlements require special attention in the development of climate resilience strategies. (1, 6)

Medellin is the second-largest city in Colombia. The city used to be one of the most dangerous in the world, as Pablo Escobar founded here the Medellin cartel. After the death of Escobar, the city's homicide rate has decreased by 95% and extreme poverty by 66%, thanks in part to a string of innovative mayors who laid out plans to integrate the poorest and most violent hillside neighbourhoods into the city centre in the valley below. The same innovative mayors realised that Columbia and its cities are very vulnerable to climate change being located in a tropical zone and is influenced by El Niño and the La Niña. In Medellin, the municipality has built upon a tradition of planning to become an urban lab for the construction of public life with the aim of inclusive, peaceful and sustainable development. As such starting in 2008 Medellin began implementing a green strategy whose goal was the creation of a green belt around the city as well as waste control. The intervention discussed in this case is one initiated in 2014 when the municipality carried out planting and reforestation projects for the protection of the eastern slopes of the city. (1,2,3)

Once empty paved area between the houses on Marat Street in St. Petersburg now has been turned into a cosy green garden [4, 5, 6]. The project was developed by a group of students and initiated by the Green Petersburg Foundation, Plants for Friends, "Vladimirsky" Municipal District and others [1, 3, 4, 5]. The square landscaping project contributes to the city's adaption to climate change, a need to increase urban green zones, reducing excessive heat and rainfall levels, and the creation of habitat for birds, among others [3]. The square acquired the concept of a harmonious combination of natural motives and the mood of the Russian landscape [4].

The Ningbo Ecological Corridor is a post-industrial landscape ecological reconstruction project. It is located in the middle of the Eastern New Town in Ningbo, with a total area of 90 hectares [4]. Built upon a typical post-industrial site with degraded ecologies that needs to be healed and would soon become part of a new urbanized district, this project is holistic ecosystem services-oriented, introducing terraced wetland to manage elevation change of the site to slow the flows of urban runoffs from the street down to the river and remove the nutrients [1]. “Before being designed, the site and surrounding areas were fragmented farmland, villages and factories that were planned to be relocated - a typical brownfield in the rural-urban fringe of the southern region of China”[1]. With the implementation of the project, "the original channelized river is transformed into a meandering eco-friendly waterway dotted with tree isles to increase the interface between organisms and water bodies to empower the river’s purification capacity. The project uses productive crops and annual flowers that are rotated to bring seasonal surprise and agricultural vitality to the growing city. Boardwalks are designed to allow visitors to have intimate experience of nature and the nostalgic pastoral landscape. Pavilions made of corten steel floats on wetlands and terraces, giving the ecological corridor a touch of contemporary urban life and art. [1] "As a result, this project demonstrated landscape as an ecological infrastructure that heals the degraded ecological system meanwhile provides social and cultural services to the establishing communities." [1]

Touted as a long-term solution to flooding of Mandaue City, establishment of a mangrove eco-park has begun, having received funding from the Department of Budget and Management (DBM) (Ref. 1). Through establishment of mangroves, the eco-park will "perform a significant role in shoreline protection, acting as a buffer against strong winds and waves", which is considered particularly important in light of the anticipated effects of climate change (Ref. 6).

A total 17-hectare plot is to be rehabilitated, as identified in the Mandaue City Government's Comprehensive Land Use Plan (Ref. 3). At present, it is unclear whether nature-based solutions (including mangrove restoration) are to be implemented across the entire 17ha of the site, but initial efforts have been focused on the restoration of a 5-ha section of mangrove forest (Ref. 2). Due to the lack of data on how exactly the remainder of the 17-ha area will be restored, the total NBS area for this project has only been recorded as 5-ha (5000m2) within this case study, rather than the entire 17,000m2 which is encompassed within the site.

The site is situated at the outfall of the Butuanon River which frequently overtops as a result of heavy rain and has been considered "biologically dead" since 1992 (Ref. 7). The site itself comprises a former dumpsite which had been "left derelict and filled with piles of trash", hence in addition to reducing flood risk, its rehabilitation will serve as green space in which "the residents of Mandaue City [can] gather and enjoy a breath of fresh air" (Ref. 2). The eco-park is considered to bring the added benefit of filtering water as it enters the Mactan Channel, in addition to reducing greenhouse gas emissions through carbon dioxide absorption (Refs. 1 & 6).

The Porsuk Stream divides the city of Eskişehir into two with a green corridor running along the shores of the stream. The Porsuk Stream served provisioning services and acted as a recreational area in the first half of the 20th century, however with increased industrial activities discharging untreated wastewater into the river, rapid urbanisation in the city and other settlements, and increased fertilisers and pesticides in the groundwater originated from agricultural practices (upstream of the Porsuk River), it became highly polluted and its ecosystem degraded severely (1,2,4,5). The Organization for Security and Cooperation in Europe (OSCE) identified the stream as one of the highly dangerous rivers in terms of pollution and health, where no living beings except viruses live (1).
Within the framework of the 'Eskişehir Urban Development Project' the 'Natural Disaster Loss Reduction Project (Porsuk Project)' has been initiated focusing on the ecological restoration of the stream, improving water quality, increasing the resilience of the city against natural disasters (as earthquakes and floods) while also reestablishing the stream's environmental and social role in the city (1). A network of natural infrastructure was created along the Porsuk by expanding public green spaces and link the entire corridor with a sustainable public transport network. (4,5)

The city of Algiers initiated in 2010 a project in order to establish a green belt around its areas and some northern municipalities. The project aims to create agro parks, allotment gardens as well as parks as a strategy for reintegrating the concept of the green belt into the Algerian territory. Through this intervention, the municipality aims to put into practice environmental values ​​linked to improved quality of life and social well-being, for the benefit of the local community. The intervention plans to introduce different species of trees and include for the first time in Africa agro parks as spaces which are designed to reconcile urban and agricultural functions in a win-win strategy. The action was thought to respond to the impacts of climate change in the country, which faces rain events that are less frequent but more intense, and droughts that are more common and longer. (1,2,3,4)