Improved stormwater management

Peru has seen a sharp increase in major flooding, prolonged droughts and water scarcity of supplies in the dry season, negatively impacting agriculture, migration, conflict and economic growth in recent years. As 71% of the world's tropical glaciers are found in Peru these climatic changes affected the country profoundly leading to a decrease in the glacial surface and creating unstable lagoons also causing natural disasters such as alluvium landslides and deadly flash foods. Glacial melt is also disrupting water flow and quality, posing a threat to the flora and fauna that rely on freshwater environments. Unsustainable management of fragile glacier ecosystems is causing environmental degradation and biodiversity loss. To counteract many of these challenges and to safeguard the communities that are in peril, in 2011, the Government of Peru together with a number of stakeholders, initiated an intervention to sustainably manage more than 200 new lakes that affect directly populations in different cities in the Ancash, Cusco and Lima regions, Huaraz being one of the cities targeted. The project benefitted downstream communities and protected fragile high-altitude freshwater ecosystems. (1,2)

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.

The Blue-Green Infrastructure (BGI) Mapping is the initiative for Identification, Mapping, and Promotion of Blue and Green Infrastructures for Sustainable Urban Ecosystem in the city of Kathmandu. In line with the 2021 World Environment Day (WED) theme “Ecosystem Restoration”, the consortium of NAXA and Institute of Himalayan Risk Reduction (IHRR) officially launched the initiative. All the datasets will be made public through both the open data portal and the OpenStreetMaps. The mapping has only started and until now, it has only mapped the blue infrastructures (rivers, canals, ponds, wetlands, floodplains and water treatment facilities). The green infrastructures will include lawns, parks, fields, forests, greenprints, natural asset maps, ecological networks and street trees. [1, 2]

Battambang is projected to experience significant effects of climate change that will have a range of impacts including changes to hydrology and the frequency and intensity of flooding and droughts. As part of an Asian Development Bank project, a technical Climate Change Core Group was established to ensure that representatives from key sectors and levels of government work together to build resilience for the town and prepare the residents for the inevitable climate change impacts in the future. Three infrastructure systems in Battambang were identified for detailed vulnerability assessments and adaptation planning by the climate change Core Group; a) a long canal system to the west of the town, b) the riverbanks near the Sor Kheng Bridge in the centre of town, c) the train station and surrounding wetlands and settlements in the centre of town. [1, 2]

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]

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).

A multi-purpose green belt (12 km in length of Batticaloa Municipal Corporation coast) was established to protect the lagoon and coastal areas, restore mangrove ecosystems and improve coastal biodiversity. The project comes under activity 1.3 of the overarching project Climate Resilient Action Plans for Coastal Urban Areas in Sri Lanka (CCSL). The project focuses on the most urgent and immediate needs of the Sri Lankan coastal cities in adapting to climate change, and mitigating risks and the severity of impacts through Disaster Risk Management (DRM). The green belt plantation was done with Casuarinas plantation in 400 ha (out of which 75% by Mandru and 25% by the Forest Department), mangrove forest redesigning and protection of the existing vegetation. [1, 2, 6]

The Gangxia 1980 green roof, a pilot of the Green Cloud project, was launched by The Nature Conservancy (TNC) in collaboration with key partners, including: Zhubo-AAO; Glocal Estate Management; and Urban Planning & Design Institute of Shenzhen (UPDIS) [1]. Located on an old building in Gangxia village in Shenzhen, the project utilizes three-dimensional light steel structures that are simple to construct and have the capacity to hold over 420 plant containers, filled with plants mostly native to Southern China [1, 2]. The original concrete rooftop is transformed by vegetation, which is capable of absorbing and preserving rainwater, creating a nature-based stormwater management system for the residential building, achieving a 65% of run-off control rate [1, 2]. As a result, a living “green cloud” is formed on a rooftop of Gangxia village, showcasing “a model to improve the urban village’s stormwater management system and its living environment” [1. p.33].

Hatirjheel area development project is a wetland restoration project that explores the possibility of reintroducing water edge elements into the city of Dhaka. The project includes both engineered infrastructure and NbS. The restored jheel (wetland) and Begunbari khal have improved storm-water management of Dhaka and made aquatic biodiversity better. It also increased green and open space in the busy capital. The intended objective of the project was to create a bridge between the densely developed old part of the city on the south and the new organised north part of the city. Spreading over 311 acres, this project has endeavoured towards improving connectivity between major urban corridors as well as acting as a retention pond to mitigate the flash flood-prone densely populated part of the area. [1,2]