City to city learning and knowledge exchange for climate resilience in southern Africa

biomass, followed by hydropower, thermal and coal-based forms which all use water in their production. Despite a relatively high electrification rate (45%) in comparison to other SADC countries, current power supplies are inadequate for meeting energy demand across the coun- try and of late the city and country have been subject to significant power load shedding which negatively affects productivity. In the past decade, both fuel and electricity shortages have hit the country partly as a result of recurrent droughts negatively affecting hydropower produc- tion and also as a result of forex and budget constraints for purchasing fuel and electricity from neighbouring countries with excess power such as Mozambique and South Africa. Windhoek. Namibia, like many countries in semi-arid areas, is characterized by high cli- matic variability in the form of persistent droughts, unpredictable and variable rainfall patterns leading to scarcity of water [61]. Coupled with rapid urbanization, the threats of persistent water scarcity are real. A growing concern is the city of Windhoek, with a population of approximately 268,000 and an urbanization rate of 3.1% per annum. This surge in the popula- tion has created many problems for urban planning and vulnerabilities such as water shortage, energy problems, poor sanitation and waste management and related health problems. The city of Windhoek is charged with the responsibility for urban planning but is constrained or challenged by the high influx of people from rural areas. Among others, the persistent

droughts and unpredictable and variable rainfall patterns, due in part to climate change, adversely affects the availability and supply of acceptable quantities and quality of water to the city of Windhoek (Table 2). This is exacerbated by the high rate of urbanization. Hence, there is a strain on service delivery, including water supply, land and infrastructural development. These issues are compounded by low quantity water available for domestic use for the city residents, and energy supply challenges. The situation is made worse by informal settlements, which tend to be fueled by rural-urban migrations that have led to increased populations in the city. Most informal structures in Windhoek are made of corrugated sheets, which the local authorities tolerate as these are temporary structures that can easily be removed while the resi- dents in the informal settlements rely mostly on wood for energy and lack access to proper sanitation facilities. Lusaka. The City of Lusaka’s 1.7 million inhabitants face significant climate related challenges such as urban flooding on a yearly basis (see Table 2). Geological factors largely contribute to flooding in the city but flood risk in Lusaka appears to be exacerbated by poor municipal solid waste management systems [62]. Large parts of the city are underlain by lime- stone, which is porous, creating underground aquifers which easily become saturated. This in turn creates a high water-table and results in flooding when the city experiences high rainfall.

The water table fluctuations do not exceed 5 metres and during the rainy season borehole water tables reach ground surface [63]. Informal settlements in the city tend to compound the multi-stressor context for Lusaka. This is because the major aerial extent (70%) of the city has developed informally and lacks proper structures to drain excess water [64]. Another major issue is the management of solid waste—garbage that is left uncollected which ends up blocking the drainage systems. Urban planners and city decision-makers do not understand how municipal solid waste interacts with climate change, infrastructure, and urban planning to affect urban flooding and flood risk (Table 2). Durban. Major flooding risks as a result of increased variability in rainfall and extreme storm events under climate change is one of the challenges facing the city of Durban (see Table 2). Durban is a middle-income African city of 3.5 million people residing under highly unequal social, economic and environmental conditions—a legacy inherited from the Apart- heid regime. However, what is notable for this city is significant strides that have been made towards the integration of climate change into planning at city level and evidence on the City learning in southern Africa PLOS ONE | https://doi.org/10.1371/journal.pone.0227915 January 24, 2020 11 / 25