scholarly journals Urbanization and Floods in Sub-Saharan Africa: Spatiotemporal Study and Analysis of Vulnerability Factors—Case of Antananarivo Agglomeration (Madagascar)

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 149
Author(s):  
Fenosoa Nantenaina Ramiaramanana ◽  
Jacques Teller
Keyword(s):  
Urban Areas ◽  
Urban Expansion ◽  
Spatiotemporal Analysis ◽  
Natural Increase ◽  
Economic Resources ◽  
Sub Saharan Africa ◽  
High Rate ◽  
Vulnerable Groups ◽  
Drainage Networks ◽  
Sub Saharan

Flooding is currently one of the major threats to cities in Sub-Saharan Africa (SSA). The demographic change caused by the high rate of natural increase, combined with the migration toward cities, leads to a strong demand for housing and promotes urbanization. Given the insufficiency or absence of adequate planning, many constructions are installed in flood-prone zones, often without adequate infrastructure, especially drainage systems. This makes them very vulnerable. Our research consists of carrying out a spatiotemporal analysis of the agglomeration of Antananarivo (Madagascar). It shows that urbanization leads to increased exposure of populations and constructions to floods. There is a pressure on land in flood-prone zones due to the exponential growth of the population at the agglomeration level. Some 32% of the population of the Antananarivo agglomeration lived in flood-prone zones in 2018. An analysis of the evolution of built spaces from 1953 to 2017 highlights that urban expansion was intense over those years (6.1% yearly increase of built areas). This expansion triggered the construction of built areas in flood-prone zones, which evolved from 399 ha in 1953 to 3675 ha in 2017. In 2017, 23% of the buildings in the agglomeration, i.e., almost one out of every four buildings, were in flood-prone zones. A share of the urban expansion in flood-prone zones is related to informal developments that gather highly vulnerable groups with very little in terms of economic resources. Better integration of flood risk management in spatial planning policies thus appears to be an essential step to guide decisions so as to coordinate the development of urban areas and drainage networks in a sustainable way, considering the vulnerability of the population living in the most exposed areas.

scholarly journals Mapping 20 Years of Urban Expansion in 45 Urban Areas of Sub-Saharan Africa

2021 ◽  
Vol 13 (3) ◽  
pp. 525
Author(s):  
Yann Forget ◽  
Michal Shimoni ◽  
Marius Gilbert ◽  
Catherine Linard
Keyword(s):  
Case Studies ◽  
Urban Areas ◽  
Urban Expansion ◽  
Local Population ◽  
Sub Saharan Africa ◽  
Annual Growth Rate ◽  
Urban Dynamics ◽  
Mapping Approach ◽  
Sub Saharan ◽  
The Impact

By 2050, half of the net increase in the world’s population is expected to reside in sub-Saharan Africa (SSA), driving high urbanization rates and drastic land cover changes. However, the data-scarce environment of SSA limits our understanding of the urban dynamics in the region. In this context, Earth Observation (EO) is an opportunity to gather accurate and up-to-date spatial information on urban extents. During the last decade, the adoption of open-access policies by major EO programs (CBERS, Landsat, Sentinel) has allowed the production of several global high resolution (10–30 m) maps of human settlements. However, mapping accuracies in SSA are usually lower, limited by the lack of reference datasets to support the training and the validation of the classification models. Here we propose a mapping approach based on multi-sensor satellite imagery (Landsat, Sentinel-1, Envisat, ERS) and volunteered geographic information (OpenStreetMap) to solve the challenges of urban remote sensing in SSA. The proposed mapping approach is assessed in 17 case studies for an average F1-score of 0.93, and applied in 45 urban areas of SSA to produce a dataset of urban expansion from 1995 to 2015. Across the case studies, built-up areas averaged a compound annual growth rate of 5.5% between 1995 and 2015. The comparison with local population dynamics reveals the heterogeneity of urban dynamics in SSA. Overall, population densities in built-up areas are decreasing. However, the impact of population growth on urban expansion differs depending on the size of the urban area and its income class.

scholarly journals Classifying and Mapping Periurban Areas of Rapidly Growing Medium-Sized Sub-Saharan African Cities: A Multi-Method Approach Applied to Tamale, Ghana

Land ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 40 ◽  
Author(s):  
Hanna Karg ◽  
Rafael Hologa ◽  
Johannes Schlesinger ◽  
Axel Drescher ◽  
Gordana Kranjac-Berisavljevic ◽  
...  
Keyword(s):  
Land Use ◽  
Rural Areas ◽  
Urban Areas ◽  
Spatial Scales ◽  
Urban Expansion ◽  
Urban Land Use ◽  
The Body ◽  
Sub Saharan Africa ◽  
Urban Rural ◽  
Sub Saharan

Periurban areas of growing cities in developing countries have been conceptualised as highly dynamic landscapes characterised by a mixture of socioeconomic structures, land uses and functions. While the body of conceptual literature on periurban areas has significantly increased over the past two decades, methods for operationalising these multi-dimensional concepts are rather limited. Yet, information about the location and areal extent of periurban areas is needed for integrated planning in the urban–rural interface. This article presents the results of a study aiming at classifying and mapping periurban areas along the urban–rural gradient of Tamale, a medium-sized city in Ghana. The study used a quantitative, multi-dimensional methodology involving the following as core elements: (1) a relative measure of how urban a place and its people are in terms of services, infrastructure and livelihoods (urbanicity index); (2) the diversity of households regarding their livelihoods and access to urban services; and (3) land use dynamics. Therefore, data from a household survey, as well as land use and other secondary geospatial data were collected and analysed at different spatial scales. The findings suggested that the periurban space consists of two main zones. Inner periurban areas are driven by urban expansion and the conversion of non-urban into urban land use is most visible here. These areas exhibit higher levels of socioeconomic diversity, compared to both rural and urban areas. Outer periurban areas are less dynamic in terms of land use change and exhibit lower building densities, and compared with rural areas, hold stronger links to the city related to the movement of people and goods. The spatial analysis revealed that periurban areas develop mainly along major transport corridors across administrative divisions, as well as in the form of periurban islands in the rural zone. This study set out to extend existing methodologies to map urban and periurban development in medium-sized cities in sub-Saharan Africa, useful for urban and regional planning beyond administrative boundaries.

Managing African Urbanization in the Context of Environmental Change

2014 ◽  
Vol 2 (2) ◽  
Author(s):  
Shuaib Lwasa
Keyword(s):  
Climate Change ◽  
Economic Growth ◽  
Social Services ◽  
Urban Areas ◽  
Urban Governance ◽  
Sub Saharan Africa ◽  
African Countries ◽  
Sub Saharan ◽  
Urbanization Rate ◽  
Development And Management

Africa’s urbanization rate has increased steadily over the past three decades and is reported to be faster than in any other region in the world . It is estimated that by 2030, over half of the African population will be living in urban areas . But the nature of Africa’s urbanization and subsequent form of cities is yet to be critically analyzed in the context of city authorities’ readiness to address the challenges . Evidence is also suggesting that urbanization in African countries is increasingly associated with the high economic growth that has been observed in the last two decades . Both underlying and proximate drivers are responsible for the urbanization, and these include population dynamics, economic growth, legislative designation, increasing densities in rural centers, as well as the growth of mega cities such as Lagos, Cairo and Kinshasa, that are extending to form urban corridors . With the opportunities of urbanization in Sub–Saharan Africa, there are also challenges in the development and management of these cities . Those challenges include provision of social services, sustainable economic development, housing development, urban governance, spatial development guidance and environmental management, climate change adaptation, mitigation and disaster risk reduction . The challenge involves dealing with the development and infrastructure deficit, in addition to required adaption to and mitigation of climate change . This paper examines the current state of urban management in Africa .

scholarly journals Fanconi Bickel syndrome: clinical phenotypes and genetics in a cohort of Sudanese children

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Salwa A. Musa ◽  
Areej A. Ibrahim ◽  
Samar S. Hassan ◽  
Matthew B Johnson ◽  
Asmahan T. Basheer ◽  
...  
Keyword(s):  
Glucose Transporter ◽  
Novel Mutation ◽  
Wide Spectrum ◽  
Rare Condition ◽  
Neonatal Diabetes ◽  
Abdominal Ultrasound ◽  
Sub Saharan Africa ◽  
High Rate ◽  
Genetic Characteristics ◽  
Sub Saharan

Abstract Background Fanconi-Bickel syndrome (FBS) is a rare condition of carbohydrate metabolism, caused by a recessive defect in the facilitative glucose transporter GLUT2 encoded by the SLC2A2 gene and characterized by a wide spectrum of phenotypical features. There is a paucity of reported data on FBS from Sub-Saharan Africa. Here, we describe the clinical, biochemical and genetic characteristics of our patients with FBS from Sudan, a country with a high consanguinity rate. Patients & methods Eleven patients from ten unrelated Sudanese families were included. Clinical & biochemical data were documented and imaging studies done including bone survey and abdominal ultrasound. Liver biopsy was done to confirm the pathological diagnosis in 45% of cases and molecular genetics was performed through contribution with the Exeter genomics laboratory for ten patients. Results Reported consanguinity was 70% among our patients. Growth was significantly impaired at presentation with mean weights of (-5.3 ± 1.8) SD and heights (-5.4 ± 2.5) SD. Severe chest deformity was present in (27%) and all patients showed features of rickets at presentation. Three patients had neonatal diabetes requiring insulin therapy of which one has been reported before. Six families lost undiagnosed siblings with similar clinical presentations. We identified a total of four homozygous pathogenic SLC2A2 variants in our patients, one of whom had a novel mutation. Conclusions FBS is not uncommon in Sudan where there is a high rate of consanguinity. Many cases are likely missed because of variable presentation and lack of public and professionals’ awareness. This is the first series to describe this condition from Sub-Saharan Africa.

The Urban Transition in Sub-Saharan Africa: Challenges and Opportunities

10.1068/c3p ◽  
2007 ◽  
Vol 25 (4) ◽  
pp. 466-485 ◽  
Author(s):  
Christine Kessides
Keyword(s):  
Urban Areas ◽  
Local Governments ◽  
Poverty Reduction ◽  
National Development ◽  
Favourable Outcome ◽  
Sub Saharan Africa ◽  
Urban Transition ◽  
Energy Needs ◽  
Challenges And Opportunities ◽  
Sub Saharan

In this paper I ask how the ongoing processes of urban and local government development in Sub-Saharan Africa can and should benefit the countries, and what conditions must be met to achieve this favourable outcome. The region faces close to a doubling of the urban population in fifteen years. This urban transition poses an opportunity as well as a management challenge. Urban areas represent underutilised resources that concentrate much of the countries' physical, financial, and intellectual capital. Therefore it is critical to understand how they can better serve the national growth and poverty reduction agendas. The paper challenges several common ‘myths’ that cloud discourse about urban development in Africa. I also take a hard look at what the urban transition can offer national development, and what support cities and local governments require to achieve these results. I argue that, rather than devoting more attention to debating the urban contribution to development in Africa, real energy needs to be spent unblocking it.

Migration as a Risk Factor for HIV Infection among Youths in Sub-Saharan Africa

2013 ◽  
Vol 648 (1) ◽  
pp. 136-158 ◽  
Author(s):  
Monica A. Magadi
Keyword(s):  
Risk Factor ◽  
Hiv Infection ◽  
Urban Areas ◽  
Young Female ◽  
Sub Saharan Africa ◽  
Demographic And Health Surveys ◽  
Country Level ◽  
Female Migrants ◽  
Sub Saharan ◽  
Living With Hiv

Of the estimated 10 million youths living with HIV worldwide, 63 percent live in sub-Saharan Africa. This article focuses on migration as a risk factor of HIV infection among the youths in sub-Saharan Africa. The study is based on multilevel modeling, applied to the youth sample of the Demographic and Health Surveys (DHS), conducted from 2003 to 2008 in nineteen countries. The analysis takes into account country-level and regional-level variations. The results suggest that across countries in sub-Saharan Africa, migrants have on average about 50 percent higher odds of HIV infection than nonmigrants. The higher risk among migrants is to a large extent explained by differences in demographic and socioeconomic factors. In particular, migrants are more likely to be older, to have been married, or to live in urban areas, all of which are associated with higher risks of HIV infection. The higher risk among youths who have been married is particularly pronounced among young female migrants.

scholarly journals GAP FILLERS OR PIONEERS: INFORMAL WATER SUPPLIERS IN PERI-URBAN AREAS OF THE TECHIMAN MUNICIPALITY OF GHANA

2021 ◽  
Vol 8 (1) ◽  
pp. 525-539
Author(s):  
Lydia Kwoyiga
Keyword(s):  
Urban Areas ◽  
Water Distribution ◽  
Water Source ◽  
Water Quality Monitoring ◽  
Distribution Networks ◽  
Sub Saharan Africa ◽  
Formal Sector ◽  
Public Provision ◽  
Sub Saharan ◽  
Municipal Assembly

There is continuous expansion and growth of urban and peri urban areas in Sub-Saharan Africa with projections indicating that this will double. Some peri-urban areas such as those in the Techiman municipality of Ghana are experiencing this trend. Nonetheless, the spate of growth of these areas outstrips the supply of utilities by municipal water distribution networks. As a result, some areas have little or no public provision. In order to address the water supply challenge, places with favourable hydrological settings are witnessing the emergence of informal water suppliers as “gap fillers” or “pioneers”, providing water services. Noteworthy, however, existing studies about informal water suppliers in peri-urban areas in Ghana lump them together, without considering the water source. This study differs in that it specifically examines the evolution and the features of informal water suppliers who privately and independently abstract and supply groundwater. Additionally, it attempts to understand the nature of informality of the suppliers and the possibility of formalisation. The paper is an exploratory study using the case of private mechanised borehole operators who supply water in their respective areas. The findings showed that in some peri-urban areas in the Techiman municipality, some dwellers constructed and operated mechanised boreholes, which provide in-situ water and utilities to others. They are mostly pioneer water suppliers in some of the areas. Their services are informal by nature because they are largely independent of the formal sector and apply informal arrangements in rendering their services. Seen also as business enterprises, they are not licenced. However, the boreholes are registered with the Municipal Assembly, which indicated some level of formalisation. The study recommended that efforts to formalise them further should focus on improving water quality monitoring for consumption and promoting sustainable abstraction.

scholarly journals The acceptance of covid-19 vaccines in Sub-Saharan Africa: Evidence from 6 national phone surveys

2021 ◽  
Author(s):  
Shelton Kanyanda ◽  
Yannick Markhof ◽  
Philip Wollburg ◽  
Alberto Zezza
Keyword(s):  
Side Effects ◽  
Low Income ◽  
Urban Areas ◽  
Vaccine Coverage ◽  
Sub Saharan Africa ◽  
Low Income Countries ◽  
Vaccine Hesitancy ◽  
African Countries ◽  
Representative Sampling ◽  
Sub Saharan

Introduction Recent debates surrounding the lagging covid-19 vaccination campaigns in low-income countries center around vaccine supply and financing. Yet, relatively little is known about attitudes towards covid-19 vaccines in these countries and in Africa in particular. In this paper, we provide cross-country comparable estimates of the willingness to accept a covid-19 vaccine in six Sub-Saharan African countries. Methods We use data from six national high-frequency phone surveys from countries representing 38% of the Sub-Saharan African population (Burkina Faso, Ethiopia, Malawi, Mali, Nigeria, and Uganda). Samples are drawn from large, nationally representative sampling frames providing a rich set of demographic and socio-economic characteristics by which we disaggregate our analysis. Using a set of re-calibrated survey weights, our analysis adjusts for the selection biases common in remote surveys. Results Acceptance rates in the six Sub-Saharan African countries studied are generally high, with at least four in five people willing to be vaccinated in all but one country. Vaccine acceptance ranges from nearly universal in Ethiopia (97.9%, 97.2% to 98.6%) to below what would likely be required for herd immunity in Mali (64.5%, 61.3% to 67.8%). We find little evidence for systematic differences in vaccine hesitancy by sex or age but some clusters of hesitancy in urban areas, among the better educated, and in richer households. Safety concerns about the vaccine in general and its side effects emerge as the primary reservations toward a covid-19 vaccine across countries. Conclusions Our findings suggest that limited supply, not inadequate demand, likely presents the key bottleneck to reaching high covid-19 vaccine coverage in Sub-Saharan Africa. To turn intent into effective demand, targeted communication campaigns bolstering confidence in the safety of approved vaccines and reducing concerns about side effects will be crucial to safeguard the swift progression of vaccine rollout in one of the world's poorest regions.

scholarly journals False-negative malaria rapid diagnostic test results and their impact on community-based malaria surveys in sub-Saharan Africa

2019 ◽  
Vol 4 (4) ◽  
pp. e001582 ◽  
Author(s):  
Oliver J Watson ◽  
Kelsey Marie Sumner ◽  
Mark Janko ◽  
Varun Goel ◽  
Peter Winskill ◽  
...  
Keyword(s):  
Urban Areas ◽  
False Negative ◽  
Poor Performance ◽  
Storage Conditions ◽  
Probability Of Detection ◽  
Sub Saharan Africa ◽  
Community Based ◽  
Sub Saharan ◽  
Lower Transmission ◽  
Demographic Patterns

Surveillance and diagnosis of Plasmodium falciparum malaria relies predominantly on rapid diagnostic tests (RDT). However, false-negative (FN) RDT results are known to occur for a variety of reasons, including operator error, poor storage conditions, pfhrp2/3 gene deletions, poor performance of specific RDT brands and lots, and low-parasite density infections. We used RDT and microscopy results from 85 000 children enrolled in Demographic Health Surveys and Malaria Indicator Surveys from 2009 to 2015 across 19 countries to explore the distribution of and risk factors for FN-RDTs in sub-Saharan Africa, where malaria’s impact is greatest. We sought to (1) identify spatial and demographic patterns of FN-RDT results, defined as a negative RDT but positive gold standard microscopy test, and (2) estimate the percentage of infections missed within community-based malaria surveys due to FN-RDT results. Across all studies, 19.9% (95% CI 19.0% to 20.9%) of microscopy-positive subjects were negative by RDT. The distribution of FN-RDT results was spatially heterogeneous. The variance in FN-RDT results was best explained by the prevalence of malaria, with an increase in FN-RDT results observed at lower transmission intensities, among younger subjects, and in urban areas. The observed proportion of FN-RDT results was not predicted by differences in RDT brand or lot performance alone. These findings characterise how the probability of detection by RDTs varies in different transmission settings and emphasise the need for careful interpretation of prevalence estimates based on surveys employing RDTs alone. Further studies are needed to characterise the cost-effectiveness of improved malaria diagnostics (eg, PCR or highly sensitive RDTs) in community-based surveys, especially in regions of low transmission intensity or high urbanicity.

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