Green infrastructure for climate adaptation in peri-urban areas

Project: Research project (funded)Research

Project Details


Our project combines multi-scalar institutional analysis, empirical data collection, and participatory scenario planning for a comprehensive understanding of the synergies and trade-offs of UGI for climate adaptation in the peri-urban areas of Sub-Saharan Africa. We focus on the overabundance or scarcity of water, given the growing need to secure a reliable water source to cities with quality and supply-demand constraints, and because cities typically rely heavily on engineering infrastructure for water storage/purification.

The project has four interlinked objectives:

Determine the impacts of seasonal variability on water supply in rural and peri-urban areas, and adaptation pathways;

Assess the comparative impacts of water-related UGI on ecosystem service provisioning and wellbeing in peri-urban areas;

Identify the barriers to the mainstreaming of UGI in peri-urban settlements for climate adaptation; and

Examine diverse, plausible scenarios to achieve desired futures for 2030 and 2063, using participatory scenario planning.

The main empirical work will use a comparative, transdisciplinary, in-depth case study research design. Work will focus on two peri-urban areas in southern and East Africa (Windhoek, Namibia and Dar es Salaam, Tanzania) that effectively represent water-related EI and associated hydro-climatic risks, and offer broad regional coverage, a range of population sizes, inland verses coastal locations, and growth rates.

Layman's description

Fifty-nine percent of Sub-Saharan African urban populations live in informal settlements (UN-HABITAT 2019), expected to triple by 2050. Despite an increase in improved housing from 11% to 23% between 2000-2015, 53 million urban Africans were still living in unimproved housing in 2015, often in highly overcrowded conditions, with large deficits in city infrastructure and public service provision, and in hazardous sites such as riparian corridors and on steep slopes (Shatterthwaite et al. 2018, Tusting et al. 2019). These complex natural and socio-cultural dynamics, combined with climate variability, severe and persistent drought, extreme rainfall and heatwaves, expose much of the population to high levels of risk, and threaten an irreversible collapse in ecosystem diversity and functioning (Thorn et al. 2015, Dodman et al. 2017, Shatterthwaite 2017).

Ecosystem-based solutions in the form of ecological (or green) infrastructure (EI or GI) have emerged as spatial planning tools for ensuring functional networks of natural and semi-natural areas. They demonstrate the importance of ecological systems as part of the infrastructural fabric that supports and sustains society and builds resilience (Harrison et al. 2014, Lindley et al. 2018, Cilliers 2019).

In various cases across Sub-Saharan Africa, well-functioning ecosystems provide diverse provisioning, regulating, supporting and cultural services to society that can buffer against risks arising from droughts and floods, and can reduce the loss of lives, assets and critical infrastructure (Kaoma and Shackleton 2014, Seburanga et al. 2014, Adegun 2018), with benefits for physical/psychological health, social equity and wellbeing (Shackleton et al. 2015, Kopecka et al. 2018). Urban green infrastructure (UGI) can lengthen the life of existing built infrastructure, make areas more attractive for investment and require minimal input and maintenance. Yet, informal urbanisation continues to intrude upon and undermine ecological space (e.g., illegal dumping, open defecation, criminality), while encroachment on formal green spaces that can be of ecological importance (Adegun 2019), especially urban parks, is common (Bhattacharya 2014, Israt and Adam 2017). Moreover, most research on UGI outcomes to enhance climate resilience has been conducted in formal settlements in the Global North, while the unique sociocultural context, and spatial challenges in Sub-Saharan Africa means that Africa must not necessarily emulate Western models of green infrastructure planning.

Producing better strategies that reverses this trend requires more fine-grained data that is impact-relevant, new metrics for risk and adaptation, and instruments that account for uncertainty in decision making. To improve predictions of future climate change without knowing the exact scale of risk, a more comprehensive assessment is needed to identify where benefits outweigh costs, and when to transfer, avoid, reduce, or accept risk.

Key findings

UGI can help recovery from hazards (e.g., poles for construction), provide a safety net (e.g., wild foods in times of drought), filter grey water, provide timber, fodder, windbreaks, and shade, promote the provision of downstream water, reduce sedimentation and run-off, complement drainage, and create opportunities for social interaction, community cohesion, foster inclusion and attachment to space.

UGI must be understood as part of the infrastructural fabric and economic good, rather than a “luxury and visual good, in comparison to more pressing needs”, particularly in small to medium sized cities where low-income and other marginalised urban residents are typically more dependent on ecosystem services than higher-income groups.

There is an urgent need for national governments, international agencies, civil society organisations, and public-private partnerships to support more capable, creative, accountable, better-resourced municipal governments. Improving community rights, state relations, community integration and reforming policing is essential for achieving successful adaptation interventions.

Integrated planning needs to prioritise capturing multiple ecosystem services and functions, zone according to ecological and historical parameters, ensure quality and accessibility in relation to function and form, and promote more even distribution in high- and low-income neighbourhoods (including backyard dwellings). Land use land cover change needs to be monitored, and urban ecosystem services not managed intensively for one type of ecosystem service at the expense of others.

With changing precipitation regimes, residents, conservation agencies, private businesses and local authorities need to work together to maintain and restore degraded wetlands, riparian corridors, and rivers to enhance flood regulation and water purification functions, and reduce contamination and the spread of communicable/waterborne pathogens.
Short titleUrban ecolution
Effective start/end date1/11/1830/09/20