Collection of monitoring data continuously throughout the project to aid evaluation

Danang, a prosperous port city in Central Vietnam, is home to a population of 1.2 million inhabitants. Throughout the years, the city went through several boats of urbanization, which allowed its economy to thrive but its environment to be negatively impacted. The city's green areas were reduced, leading to socioeconomic and environmental impacts, including loss of landscape and more energy consumption. (4) Furthermore, the city became vulnerable to natural disasters, which caused destruction and uprooting of trees and vegetation and aggravated soil erosion. (3,4)
To counteract many of these issues, the municipality of Danang initiated several greening activities that included the creation of parks, the greening of street alleys, and the greening of schoolyards as a supporting mechanism for one of Vietnam's nationwide programmes "Plant 1 billion trees in the 2021 - 2025" (5). Recently, the municipality planted 900 Than Mat trees (one of the typical flowering plants of Son Tra Peninsula and scientifically known as Millettia nigrescens Gagnep) along the route from Green Lake to Bai Bac, in the Tho Quang ward, in February 2023. The activity also aims to have an educational role as tree protection is highlighted and build a clean and green city environment (6).
So far, as of February 2023, as part of the 1 billion tree programme, 15,000 trees have been planted in Danang. (2)

Odom Garden is a unique temporary pop-up public garden developed as a part of an ongoing real estate project (Ref 1). The garden was developed in 2020 to provide a green public space for people to connect with nature and with other citizens in a prime real-estate planned area for further construction in 2023 (Ref 1). Spread across 4000 sqm, the garden is developed by employing and upcycling the garden's native elements, such as large branches being converted into balancing paths and swing holders (Ref 3). The garden is a very popular green space in the city with Phnom Penh’s first dog park, a Japanese-inspired foot bath, and a central food and beverage area, as well as a children’s playground (Ref 2, 3). This green space has become a meeting place for families with opportunities for relaxation and recreation.

The park has been functioning since 2020 as a temporary site for the future Odom project. The area will be redeveloped to include a residential and commercial complex that includes a five-story layered park (Ref 1, 2). The project, when complete, is expected to increase the total green space area to 7000 sqm, i.e., 126% of the current Odom Garden. Of this, 80% of the green space will be accessible to the public. The Odom garden can thus be interpreted as a demonstration intervention, where the goal was to create s community-focused space and in which Phnom Penhers can experience the sense of community envisioned for the future completed project (Ref 1, 2). As of January of 2023, it has been announced that the Odom Garden is closing for the pre-construction of ODOM, with a "heartfelt: See You Soon" (Ref. 5).

Located in downtown Bandung, with an area of 3.8 hectares, Babakan Siliwangi (more commonly known as Baksil) has been declared The World City Forest on September 27, 2011, by the United Nations Environment Programme (UNEP). It is part of the green belt of Bandung and is a place of recreation for residents and features a canopied walking path. Declaring the forest as part of the urban green belt of the city has not been an easy task for the management team of Baksil as in 2011, there was a plan to build privately-owned multistories building at the site, which would greatly reduce the environmental quality of the area. In response to this challenge, the team initiated a series of awareness actions as well as a planting campaign to raise the profile of the forest, as well as to address several environmental challenges such as emissions reduction, noise pollution, soil degradation, and fauna and flora conservation. The intervention proved to be very successful as it established the Baksil forest as a new public space that enabled people to get to know and better appreciate their city forest. Several communities have been holding events in this area to activate the idle space, while inviting more people to interact with the forest, making it to be invaluable for the local community and the city of Bandung. (1,2,3,4,5)

Revitalizing Informal Settlements and their Environments (RISE) is one of the pilot projects carried out in the Batua neighbourhood (1.9 km2 area) of Makassar City (119 km2 area), province of South Sulawesi in Indonesia, which was commenced in 2017 and concluded in 2022 (1,2,3). Batua neighbourhood (six settlements of around 1,600 people) was the first demonstration site for this project which was completed in 2019 (3,4,5). The main challenge was that many households who lived in informal settlements lacked access to centralized urban infrastructure and faced threats from climate change (3,4). The project was proposed to reduce the impact of climate change on marginalized communities in Makassar by providing localized, water-sensitive interventions that addressed issues related to sanitation and water management (1,2,3,4). The introduction of water-sensitive solutions enabled targeted communities to recycle wastewater and rainwater, restore natural waterways, improve water quality, and reduce vulnerability to flooding (3,4). The RISE program initiative integrated nature-based solutions like wetland restoration, bio-filtration gardens (the process of using beneficial bacteria to clean water on a molecular level to remove contaminants), stormwater harvesting, filtration paths and new sanitation structures to improve wastewater management and diversify water resources through community-driven development (1,2,3,4).

Indonesia’s peatlands are among the most vulnerable ecosystems on Earth and also have significant potential as carbon sinks (1,2). Fire risk in Sumatra's peatland areas is high due to canals that were dug for logging and plantation development (1,2). The Sumatra Merang Peatland Project was thus launched to restore the area as the massive forest fire in 2015 destroyed thousands of hectares of biodiverse tropical forest (1). This project includes restoring more than 22,900 hectares of peatland rainforest in the Merang region, located within Musi Banyuasin Province, South Sumatra in Indonesia (1,2,3). The project targets the Merang biodiversity corridor, one of the largest and deepest peat swamps in South Sumatra, which protects an area more than 3.5 times the size of Manhattan (New York City) (1,2,3). This project is a part of the Althelia Climate Fund and was implemented on the ground by Indonesian Companies named PT Global Alam Lestari (GAL) and Forest Carbon (1,2,3,4,5). The project aims and contributes to climate change mitigation and ecosystem resilience by peat rewetting and reforestation, protecting biodiversity and working with local communities to build and improve livelihoods (1,3).
The first stage of the project is considered completed and is considered to achieve positive impacts already, but it still aims to upscale certain activities until 2025 (3,4,5). The total lifetime of the project extends to 2062 (4).

The rehabilitation of the Klang River or Selangor Maritime Gateway (SMG) is a project that was put into effect in 2018 by the Selangor State Government. The project aimed to transform the Klang River, considered the most polluted river in Malaysia, into a beautiful and clean river which can be a new source of economic growth in the state of Selangor, Malaysia. The river has been polluted with trash, plastic bottles, and sewage, which harmed the vegetation and the aquatic ecosystem (1). The project proved to be highly complex as it included rehabilitation of the river through several green solutions such as the creation of a community park, the conservation of various species of mangroves, and the implementation of riverfront greens as a measure of slope protection. The intervention is set to be developed on an area of 56 Km along the Klang River corridor. It is expected to promote and support the integrated management of river basins with particular emphasis on ensuring that biodiversity and wetland conservation and community considerations are incorporated into river basin management that includes the development of eco-city (3,5,6). Furthermore, the project intends to conduct an awareness campaign about river cleaning and rehabilitation activities to educate the public on the importance of rivers and the environment in our lives while consequently highlighting the critical state of pollution faced by the River (1).

Nazarbayev University (NU) launched the Green Campus (GC) project in 2016 to promote environmental sustainability (2). The GC concept is based on principles of the sustainable development and aims to focus on the greenhouse gas emissions reduction and waste management processes (1, 5). The university has established a Green Campus office, a Green Campus University Committee and the NU Green Society for the implementation of the project (2).

One of the main activities of the Green Campus is organizing tree-planting events on campus. To date, more than 1000 trees have been planted, with funds donated by university sponsors or raised via the collection and recycling of campus wastepaper [3, 4]. Additionally, the initiative also implemented a separate waste collection process for six types of waste: paper, plastic, glass, metal, batteries, and light bulbs. The collected waste is sent for recycling to selected companies [2].

Before Earth Day, NU also hosts an annual Green Week in April, to promote sustainability practices within its community. The Green Week program typically includes eco-talks by experts, workshops, garage sales, vegetarian food fairs, eco-trips, art exhibitions, and environmental movie screenings [2, 4, 5]. Climate Week, training courses, and Climate Launchpad are also part of the university's green initiatives to educate students on environmental practices [5].

A 7-hectare pilot public project, the Tebet Eco park is located in South Jakarta in a neighbourhood that is densely populated. Previous to the intervention the park was in an acute state of deterioration and prone to floods as well as ecological degradation, as the park is streamed by a river which made it only more susceptible to heavy rains. As such, the municipal authorities of Jakarta planned to revitalize the area by " increasing the hydraulic capacity of existing canal, improving site-wide pedestrian connectivity, and adding new recreation program". This meant that the park was transformed by planting and conserving new and older trees, as well as using vegetation and natural embankments. Furthermore, the implementer planted riparian vegetation to improve water quality by filtering and cleansing surrounding runoff, which also enhanced the site's biodiversity. Besides these elements, a thematic garden, a forest buffer, and a community garden were implemented complementing the entire eco-design that the park aimed for. The park's rehabilitation focused greatly on the human element as it was paramount to provide maximum benefits for park users, the surrounding natural habitats and species, as well as increasing the land value of the area. (2,3,7)

In 2018, the Bulat Utemuratov’s Foundation began reconstruction works at the main Botanical Garden in Almaty at the request of the Institute of Botany and Phytointroduction and with the support of the governor of Almaty city [1, 5, 6]. The goal of the project was the restoration of the botanic garden with preservation of its original green character and the modernization of its infrastructure [2, 5]. Taking into account the special status of the Botanical Garden and the high public interest in the reconstruction project, the Foundation ensured full transparency to the public. Taking public recommendations into considerations, the schematic design of the reconstruction was approved in the autumn of 2018 [6]. The project also aimed to do no harm to the existing flora and fauna of botanical gardens, and apply new technology to provide long service life to the garden [1, 4].

To achieve the project's goals, the water supply system was restored, drip and auto irrigation systems were created. Around 174.3 thousand plants were planted, including more than 1300 trees. Additionally, 50 thousand sq.m of roads and paths were repaired, lighting systems and video surveillance systems were installed, and the garden furniture was renovated [1]. The project also resulted in the development of three new entrance pavilions with an electronic ticketing system. A mobile application with a garden map and a description of the green areas has been developed [5]. Special attention was paid to the accessibility of all zones of the Botanical Garden for low-mobility groups. [1, 4, 5, 6].

Confirming the success of the project, within three months after the reconstruction was completed, over 210 thousand persons visited the Almaty Botanic Garden [6].

In 2010, to revamp the Raja Musa Forest Reserve (RMFR), a rehabilitation project was initiated by the Friends of North Selangor Peat Swamp Forest Association (a local NGO) in collaboration with governmental and non-governmental stakeholders. As part of the largest peat swamp forest complex on the West Coast of Peninsular Malaysia, the Raja Musa Forest Reserve (RMFR) is an important home to many threatened species, as well as a valuable ecosystem in the fight against global warming. Despite this, over the years the forest has been subjected to fires and illegal encroachment which severely reduced its area (1). The project was considered unique as it was an innovation aimed to enhance and strengthen the capacity of the local community in peatland water management and forest rehabilitation works (3,5). Activities included among others rehabilitation of the degraded peat forest through the plantation of new seedlings, demonstration of, and provision of a documentary model for community-based peat swamp forest rehabilitation, as well as the creation of an awareness programme with the local community and dissemination of educational materials (2).
The importance of the intervention consists not only in the implementer's approach in regard to nature-based solutions but also in its aim of documenting a "model of low-cost hydrologic restoration of peat swamp forest" which ultimately should be replicated in similar conditions but in various locations (2).