Climate Change Vulnerability in Southern African Cities

Research into adaptation strategies to climate change has become a point of great interest for today’s urban environmental planners. At the same time, addressing adaptation to climate change in Sub-Saharan cities is an ethical and epistemological challenge. This article presents an approach, developed in the context of a scientific collaboration between an Italian and a Tanzanian university, to adaptation planning in the coastal peri-urban areas of the city of Dar es Salaam. After situating the research within the international discourse on responses to global warming, the specific spatial context of the study is introduced, together with the assumptions that derive from the interpretive key: the adaptive capacity of inhabitants. The three theoretical pillars upon which the approach is based are also explored: uncertainty as an opportunity for an unfettered vision of the city’s future; the centrality of incremental environmental stress in assessment of vulnerability to extreme weather and climate events; and crossing boundaries within science and between science and society for an effective and equitable definition of the problem.

In the region south of the Sahara, flooding is the most common natural hazard. Large cities are increasingly affected: 7 in the 1980s, 27 in the 1990s, 37 in the 2000s, and 7 more since 2010. Although many studies link this trend to climate change, our understanding of natural events is still too fragmentary to allow us to appreciate the correlation between precipitation and floods. When attempting to bridge this gap, we should also consider how rainfall affects a city’s entire watershed (which can be quite extensive). By contrast, the impact of flooding on places, goods, and people is much better understood. Such effects can be so extreme as to bring the economies of large cities to their knees. Over time, the concept of risk as a product of hazard and vulnerability has expanded to include exposure and climate change adaptation. Mapping flood risk is the first step towards identifying adaptation measures, yet only one of the 11 large cities most affected by floods has a detailed flood risk map. Three of the 11 have adopted climate change adaptation strategies and plans. The remaining eight cities use an array of tools whose impact on flood risk reduction is not yet detectable.

This chapter addresses causative factors and institutional response capacity to cope with the impacts of climate change in Dar es Salaam. Rapid population growth in the city has increased both environmental and socio-economic pressures, and has led to a worsening of settlement systems and patterns. Meanwhile, haphazard urban development has led to land degradation due to stone and sand mining, air and water pollution from untreated domestic and industrial waste, land and scenery pollution due to solid waste, the disappearance of green belts, and the loss of biodiversity. Recurrences of drought conditions and increased rainfall intensity have had significant social and environmental impacts, resulting in power and food shortages, losses of livestock and agricultural crops, and flood-related damages to infrastructure, human settlements, and livelihoods. Such conditions often correspond to the spread of diseases like malaria, diarrhea, and cholera, which have economic impacts for the government and families. Moreover, coastal erosion, loss of coastal and marine ecosystems, saline intrusion in freshwater bodies, inundation of low-lying coastal areas, and reduced freshwater flows due to sea level rise are evident. A number of adaptation strategies are in place that entail community involvement in planning processes.

This chapter is part of a project that aims to identify climate change vulnerability scenarios for the inhabitants of Dar es Salaam’s coastal areas, with specific reference to the phenomenon of seawater intrusion. The rapid urbanization that has taken place in Dar es Salaam over the past 20 years has resulted in a significant increase in anthropogenic pressure (qualitative and quantitative) on the coastal aquifer, causing an acceleration in groundwater salinization processes, due to both seawater intrusion and the leakage of pollutants. Seawater intrusion could be further amplified in the medium and long term by the expected consequences of climate change. This work presents the conceptual and methodological framework adopted to identify scenarios of population exposure to seawater intrusion, based on specific indicators of the phenomenon and their correlations with climate change representative variables. Based on historical data integrated with a specific hydrogeological survey campaign carried out in 2010, a first application of that framework has been tested on a limited portion of Dar es Salaam’s coastal area. This allowed for a preliminary assessment of seawater intrusion indicators, as well as an evaluation of their efficacy when analyzing the evolution of the phenomenon over the last decade.

Urban sprawl is a major cause of environmental change, indirectly affecting climate processes on both the global and local scale and impacting the livelihoods of people who are directly dependent on ecosystem services. In the case of rapidly sprawling cities, land cover monitoring is a spatial planning requirement that must keep pace with urban growth, for the purpose of providing timely responses to environmental change and thus reducing people’s vulnerability. Due to the lack of financial resources, Least Developed Countries need affordable methodology for rapid and effective land cover monitoring, suitable for low cost equipment. This chapter presents a methodology for monitoring land cover changes in Dar es Salaam, Tanzania, developed in the context of a project for the enhancement of local authorities’ capacity to assess vulnerability to climate change and mainstream adaptation objectives into urban development plans. This methodology relies on the classification of free Landsat images and is implementable using open-source software, with the specific purpose of making sustainable the continuous assessment of urban sprawl for Dar City Council’s planning services. The methodology phases are described, from preprocessing to processing. This includes the use of a free open-source plugin for QGIS, developed during the project, which allows for the semi-automatic classification of images. Classification results demonstrate the conspicuous urban growth of Dar es Salaam from 2002 to 2011, and provide insight into the relationship between urban sprawl and population growth.

Despite the increasing number of studies on urban vulnerability in African cities, there has been little research focusing specifically on the determinants of adaptive capacity. However, a greater emphasis is now being placed on the role that local responses and socioeconomic conditions play in determining vulnerability to climate stress or climate change. Such considerations have led to an increase in the attention paid to adaptive capacity, to the social context in general, and to the specific structural conditions that cause social and urban vulnerability. The purpose of this chapter is to provide knowledge regarding the identification of the determinants and attributes of adaptive capacity in the peri-urban areas of Sub-Saharan cities. The study describes a household survey conducted in Dar es Salaam with a focus on the natural resource systems upon which people depend. Its main contribution is the generation of knowledge on household characteristics and autonomous adaptation strategies, and a framework for better understanding the relationship between these two aspects. This relationship is the basis for understanding the nature and components of adaptive capacity in coastal Dar’s peri-urban areas, and for identifying interventions that could be carried out by local institutions in order to support autonomous adaptation and environmental management practices and to improve adaptive capacity.

Mainstreaming of adaptation to climate change is recommended by many international agencies and authors of climate change literature in order to guarantee more efficient use of financial and human resources than occurs when adaptation is designed, implemented, and managed as a series of stand-alone activities. Nevertheless, there is ongoing debate over how to proceed in order to achieve effective mainstreaming, at what level to act, on what topics to concentrate, and what type of initiative should be prioritized. The article offers information and arguments that may help the administrations of Sub-Saharan cities implement the options that are most appropriate for their specific conditions. The first section situates the mainstreaming of adaptation to climate change within the more general and consolidated strategy of the Environment Integration Policy, and outlines the current process of conceptualizing the question. The mainstreaming approach is compared to the action-specific approach in order to better highlight its strengths and weaknesses, while the risks of ineffective mainstreaming are explored with particular reference to the case of Tanzania. A more detailed examination follows of possible topics and the approaches used for mainstreaming in sectoral policies related to urban development and environmental management. Lastly, the specificity of Sub-Saharan cities is addressed, which raises both concerns and hopes for the current advantages of pursuing adaptation through mainstreaming at the local level.

In order to face Climate Change, cities should have a complex system of adaptation capacities and abilities. Cities should involve everyone in this process, disseminate information, and spread awareness of Climate Change issues. Conventional studies and approaches are based on scientific knowledge that rarely takes into consideration the socio-cultural aspects and practices prevalent in specific contexts. The assumption on which this chapter is based, however, is that inclusion of these components is important and even necessary to starting a real process of adaptation. Therefore, we consider adaptation as a continuum in which strategy development depends on the relationships between local authorities, the private sector, researchers, and civil society. In this context, building adaptive capacity, knowledge sharing, and the delivery of adaptation actions become phases of the methodology. Malika, a peri-urban area of Dakar in Senegal, has been vulnerable to flooding since 2005, undermining dwellers’ daily lives and productive activities, particularly agriculture. This chapter aims to highlight how the sharing of knowledge on Climate Change, through a participatory approach, can be a useful tool in the decision-making processes that characterize urban planning.

As stated in the fourth report of the Intergovernmental Panel on Climate Change (IPCC), climate change is affecting temperatures, sea levels, and storm frequencies in the entire world. While changes in average conditions can have serious consequences by themselves, the main impacts of climate change will be felt through weather extremes and the consequent risk of natural disasters. This chapter provides an overall picture of the climate conditions in the Maputo region, through the analysis of climatic data from the Maputo-Mavalane station (1960–2006). The current climate dynamics are analyzed and future climate scenarios are briefly considered, based on the literature of Mozambique. The study is especially focused on the aspects that most influence the management of a large city like Maputo. As such, attention is centered on the analysis of intense phenomena. The aim of this work is to contribute to local administrators’ understanding of climatic phenomena and their processes.

Coastal erosion and loss of coastal environments are worldwide phenomena. These typical processes occur on different spatial and temporal scales, from river basins to coastlines, and from the ocean-atmosphere system to the global climate scale. All climate change scenarios foresee an increase in the global mean sea level in the next century, from a few tens of centimeters to over a meter. However, these scenarios are not sufficient to explain the accelerating erosion that already occurs today. In coastal areas, such change appears to be linked not only to sea level rise as a direct cause, but also to changing climatic conditions (changes in the rain distribution, winds, sea waves, etc.) and to increased human pressure on land (excessive use of weirs and dams along watercourses, loss of coastal dunes and areas of protective vegetation such as mangroves, etc.). The case of Maputo is quite informative, as none of the known effects of climate change is the main cause of the significant erosion processes that occur there today. Rather, this erosion is attributable to an altered balance between the contributions of sediment from neighboring river basins and to certain effects of coastal dynamics.

The identification of flood-prone urban areas is of special interest to the majority of Sub-Saharan cities hit repeatedly by this type of disaster. This chapter presents the sources of information and a snapshot of methods used to identify areas prone to flooding due to heavy rains and sea level rise, information that is of use to the municipality of Maputo, Mozambique. This particular case is significant, given the disastrous events that have occurred there in the past few years and which can be attributed to climate change (INGC 2009). The sources of information available were compared and validated. The Modified Normalized Difference Water Index (MNDWI) calculated on the first available LANDSAT 7 ETM satellite images after the extreme rains of 6–8 February 2000 has proven to be the best method for the Maputo case. The snapshot method used allowed us to identify 57 km² of area exposed to flooding (16 % of the municipality). This result could be improved by georeferencing the flooded blocks systematically detected by district officers after each episode of heavy rain, and examining their correlation with the intensity of the physical events that led to their flooding.

This article assesses flood risk due to heavy rains and sea level rise in the municipality of Maputo (Mozambique) (1.1 million inhabitants in 2007, 346 sq km). The risk assessment methodology took into consideration four factors (hazard, vulnerability, exposure, and adaptation) using the formula \( {\text{R}} = {{\left( {{\text{H }} \times {\text{ V}} \times {\text{ E}}} \right)} \mathord{\left/ {\vphantom {{\left( {{\text{H }} \times {\text{ V}} \times {\text{ E}}} \right)} {\text{A}}}} \right. \kern-0pt} {\text{A}}} \), where R = risk, H = hazard, V = vulnerability, E = exposure, A = adaptation. The four factors are measured using different indicators (rainfall, return periods of heavy rains and extreme tides, nature of the soil, density and poverty of population, etc.). The study uses photo interpretation of high-resolution satellite images, population figures, and terrain data, analyzed through the use of open source GIS software and on-site information. Eleven flood prone areas are identified: eight threatened by heavy rains and three by sea level rise. According to these results, an estimated 7 % of the population of Maputo lives in areas (106 ha) where the flood risk is greater than 6 on a scale of 1–10.

This chapter presents the adaptation baseline for flooding caused by extreme rains, sea level rise, and high tides brought on by climate change in the municipality of Maputo (1.1 million inhabitants in 2007, 347 km²). Adaptation measures were ascertained over the 57.4 km² exposed to regular flooding through interviews with district and neighborhood officers and on-site inspections. The size of the areas exposed to flooding (16 % of the administrative surface), their dispersion in 21 fragments and the fact that many measures are not detectable by means of surveys has complicated the work. The importance of adaptation is defined for each exposed area on the basis of the physical, economic, social, and health consequences of its absence and is expressed as a figure that can be used in risk equations. A focus group set up with members of the environmental directorate of the municipality of Maputo identified short, medium, and long-term measures, prioritized those measures according to five criteria, and discussed the mainstreaming of adaptation in planning tools.

The vulnerability of a community is usually defined in relation to an outcome, such as hunger, following a natural catastrophe, like drought or flood. Present challenges demonstrate that emergencies are multi-faceted and that risks are not the result of physical events alone. Changes to ecological, economic or social relations and structures erode the adaptive capacity of communities, which become locked into an undesirable, vulnerable state. This chapter focuses on the ways in which a particular set of changes related to economic liberalization affect the vulnerability context in rural areas of the Caia District, in central Mozambique. The factors on which this study focuses include the modernization and resettlement policies of the district government; the market economy and its potential effects on agricultural incomes; and the land tenure investments of private firms and the increasing competition between farmers and commercial interests over access to land and natural resources. Drawing from household survey data and key informant data, we argue that the changes to economic and social relations that are occurring in the district may compromise families’ capacities to cope with climate changes, and jeopardize their possibility of remaining on their existing development trajectory or making the transition to a better one.

The main lessons learned from the case studies presented in this book are reviewed in order to formulate recommendations for further research and action in adaptation to climate change. First, the present state of knowledge on the main components of vulnerability to climate change in large Sub-Saharan cities is assessed. To that end, the following set of components has been identified: hazard, sensitive area, exposure, adaptive capacity, adaptation measures, and risk. Next, a series of steps for improving available knowledge before or during planning adaptation is defined. Lastly, the issue of how to identify the most opportune adaptation options and measures is examined and a five-step process for planning adaptation is proposed as follows: 1. Identify possible measures; 2. Localize measures; 3. Plan measures; 4. Manage measures; and 5. Identify entry points. Challenges and related recommendations are outlined for each step of the process, with reference to the case studies of Dar es Salaam, Tanzania, and Maputo, Mozambique.