Assessing Floods and Droughts direct impacts in sub-Saharan Africa by using a regional hydrologic model: a fully probabilistic approach

2021 ◽  
Author(s):  
Gabellani Simone ◽  
Roberto Rudari ◽  
Keyword(s):  
Urban Areas ◽  
Flood Hazard ◽  
Probabilistic Approach ◽  
Hydrologic Model ◽  
Sub Saharan Africa ◽  
Economic Losses ◽  
Climate Conditions ◽  
Physically Based ◽  
Floods And Droughts ◽  
Sub Saharan

<p>Over the last few decades, disasters resulting from natural hazards have often derailed hard-earned development progress. This is especially true in developing countries such as in sub-Saharan Africa which was the object of this study. The majority of disasters in Africa are hydro-meteorological in origin, with droughts affecting the largest number of people and floods occurring frequently along major river systems and in many urban areas. Disasters, however, can be significantly minimised with rigorous understanding of the risk, obtained using scientific risk modelling and through effective institutional and community prevention, mitigation and preparedness. Specifically, this study focuses on the risk assessment due to both Floods and Droughts in 16 countries in Sub-Saharan Africa. The study describes the crucial role of a physically based regional hydrologic model as a common engine to assess drought and flood hazard and their subsequent risk implications on people and economy. The hydrologic simulations are at the basis of the fully probabilistic approach adopted in the study. The study develops risk estimates in both current and future climate conditions, using RCP8.5 projections, paired with socio economic development (i.e., considering population and GDP growth). Results are discussed in terms of impacts on population and different key sectors of the African economy, such as agriculture and infrastructure, while especially focusing on the direct economic losses caused by flood and drought disasters and on the  food security implications of drought disasters.</p>

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 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 Prevalence of mastitis in Nigerian livestock: a Review

2020 ◽  
Vol 1 (1) ◽  
pp. 20-29
Author(s):  
Hussaini Ojagefu Adamu ◽  
Rahimat Oshuwa Hussaini ◽  
Cedric Obasuyi ◽  
Linus Irefo Anagha ◽  
Gabriel Oscy Okoduwa
Keyword(s):  
Control Strategies ◽  
Dairy Farms ◽  
Livestock Production ◽  
Sub Saharan Africa ◽  
Economic Losses ◽  
Ecological Development ◽  
Management Plans ◽  
Sub Saharan ◽  
Control And Management ◽  
The Impact

AbstractMastitis is a disease of livestock that directly impede livestock production and thus hindering the socio-ecological development of sub-Saharan Africa. Studies have estimated the prevalence of this disease in 30% of Africa countries, with Ethiopia having the highest prevalence. The coverage is low, despite the wide livestock and dairy farms distribution in Africa. Furthermore, estimated economic losses due to the impact of mastitis are lacking in Nigeria. The disease is endemic in Nigeria as indicated by the available data and there are no proposed management plans or control strategies. This review is thus presented to serve as a wakeup call to all parties involved to intensify efforts towards the diagnosis, control, and management of the disease in Nigeria.

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.

scholarly journals Calibration and evaluation of a semi-distributed watershed model of Sub-Saharan Africa using GRACE data

2012 ◽  
Vol 16 (9) ◽  
pp. 3083-3099 ◽  
Author(s):  
H. Xie ◽  
L. Longuevergne ◽  
C. Ringler ◽  
B. R. Scanlon
Keyword(s):  
Regional Scale ◽  
Water Storage ◽  
Hydrologic Model ◽  
Sub Saharan Africa ◽  
Model Parameters ◽  
Total Water ◽  
Discharge Data ◽  
Model Based ◽  
Grace Data ◽  
Sub Saharan

Abstract. Irrigation development is rapidly expanding in mostly rainfed Sub-Saharan Africa. This expansion underscores the need for a more comprehensive understanding of water resources beyond surface water. Gravity Recovery and Climate Experiment (GRACE) satellites provide valuable information on spatio-temporal variability in water storage. The objective of this study was to calibrate and evaluate a semi-distributed regional-scale hydrologic model based on the Soil and Water Assessment Tool (SWAT) code for basins in Sub-Saharan Africa using seven-year (July 2002–April 2009) 10-day GRACE data and multi-site river discharge data. The analysis was conducted in a multi-criteria framework. In spite of the uncertainty arising from the tradeoff in optimising model parameters with respect to two non-commensurable criteria defined for two fluxes, SWAT was found to perform well in simulating total water storage variability in most areas of Sub-Saharan Africa, which have semi-arid and sub-humid climates, and that among various water storages represented in SWAT, water storage variations in soil, vadose zone and groundwater are dominant. The study also showed that the simulated total water storage variations tend to have less agreement with GRACE data in arid and equatorial humid regions, and model-based partitioning of total water storage variations into different water storage compartments may be highly uncertain. Thus, future work will be needed for model enhancement in these areas with inferior model fit and for uncertainty reduction in component-wise estimation of water storage variations.

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 A metric-based assessment of flood risk and vulnerability of rural communities in the Lower Shire Valley, Malawi

2015 ◽  
Vol 370 ◽  
pp. 139-145 ◽  
Author(s):  
A. J. Adeloye ◽  
F. D. Mwale ◽  
Z. Dulanya
Keyword(s):  
Rural Communities ◽  
Spatial Variability ◽  
Flood Risk ◽  
Flood Hazard ◽  
Sub Saharan Africa ◽  
Structured Interviews ◽  
Adaptation Measures ◽  
Flood Depth ◽  
Inundation Area ◽  
Sub Saharan

Abstract. In response to the increasing frequency and economic damages of natural disasters globally, disaster risk management has evolved to incorporate risk assessments that are multi-dimensional, integrated and metric-based. This is to support knowledge-based decision making and hence sustainable risk reduction. In Malawi and most of Sub-Saharan Africa (SSA), however, flood risk studies remain focussed on understanding causation, impacts, perceptions and coping and adaptation measures. Using the IPCC Framework, this study has quantified and profiled risk to flooding of rural, subsistent communities in the Lower Shire Valley, Malawi. Flood risk was obtained by integrating hazard and vulnerability. Flood hazard was characterised in terms of flood depth and inundation area obtained through hydraulic modelling in the valley with Lisflood-FP, while the vulnerability was indexed through analysis of exposure, susceptibility and capacity that were linked to social, economic, environmental and physical perspectives. Data on these were collected through structured interviews of the communities. The implementation of the entire analysis within GIS enabled the visualisation of spatial variability in flood risk in the valley. The results show predominantly medium levels in hazardousness, vulnerability and risk. The vulnerability is dominated by a high to very high susceptibility. Economic and physical capacities tend to be predominantly low but social capacity is significantly high, resulting in overall medium levels of capacity-induced vulnerability. Exposure manifests as medium. The vulnerability and risk showed marginal spatial variability. The paper concludes with recommendations on how these outcomes could inform policy interventions in the Valley.

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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