Flooding in Informal Settlements: Potentials and Limits for Household Adaptation in Dar es Salaam City, Tanzania

Rapid urbanization and climate change are compounding the vulnerability of the urban poor to natural hazards, particularly in the global south. Large number of the population in cities of developing countries live in informal settlements characterized with lack of infrastructure facilities and services. Majority of the informal settlements are located in risk areas such as low-lying lands and river banks whereby climatic threats associated with flooding are common. The urban informal settlements are thus disproportionately more vulnerable due to their greater exposure associated with their geophysical location, under-invested infrastructure facilities as well as poor housing quality. While it is widely acknowledged that the need to adapt to climate change related hazards such as flooding is no longer an option, literature suggests that potentials and opportunities for adaptation are unevenly distributed among global regions, communities, sectors, ecological systems as well as across different time periods. This study sought to explore the potentials and limits of households living in flood prone in an informal settlement of Magomeni Suna, Dar es Salaam Tanzania. The study employed a mixed method research design using both quantitative and qualitative data collection and analysis. Quantitative data were collected through a structured questionnaire administered to 199 randomly selected respondents, while non participant observation was used to capture information related to household physical adaptation measures. Key informant interviews were used to elicit data from purposively selected representatives of government and other local institutions. Two focus group discussions supplemented the data collected through the other methods. The results show that households employ multiple options for flood adaptation ranging from structural measures aimed at preventing flood water from entering the houses, to action oriented strategies such as relocation. The results also highlight there exist potentials like strong social networks, cohesive communities, and presence of various local institutions willing to support household responses to floods. Limitations to flood adaptation include little support and ad hoc intervention by government authorities, as well as meagre household income. To enhance household adaptation to flood hazards, policy measures towards enhancing social networks and community actions for flood adaptation are necessary. There is also a need to enhance multi institutional involvement as well as promote local livelihoods so as to improve household adaptation to floods.

Vulnerability and everyday health risks of urban informal settlements in Sub-Saharan Africa

More than half of the world population lives in the cities and around one billion in poor urban areas.These numbers are projected to increase,while Sub-Saharan Africa is the region with the highest rate of informal settlements due his rapid urbanization.The urban informal settlements of Sub-Saharan Africa house everyday health risks.These risks have considerable cumulative impacts on the wellbeing and health of the urban vulnerable group.Despite the public health consequences of urbanization and the increase of informal settlements number in African cities,there is a paucity in data about the risks at small scale and the vulnerability in poor urban areas.Through the database search engine of MEDLINE,WHO Library and Information Networks for Knowledge and website of Urban Africa Risk Knowledge;from information of the existing literature,this paper tried to analyse the everyday health risks,and vulnerabilities in urban informal settlement in Sub-Saharan Africa region.A search combining keywords associated with health risks and informal settlement in Sub-Saharan Africa were used to identify the relevant documents,and this search yielded 86 articles,of which 15 met the criteria for inclusion in the analysis.The risks of communicable diseases due to inadequate sanitation have been the most frequent subjects of study.Informal settlers in Sub-Saharan Africa face everyday health risks arising from lack of clean water,adequate sanitation,and life in overcrowding houses.Consequently,there is a burden of communicable and non-communicable diseases,undernourishment and injuries.The most vulnerable group is children under five with a high rate of mortality.Everyday health risks in urban informal settlements must be taken into account for a better understanding of the full spectrum of urban risks.This is essential in the establishment of efficient public health policies and intervention in urban areas.

Determinants of inequality in health care seeking for childhood illnesses:insights from Nairobi informal settlements

Background:An in-depth understanding of patterns of inequities in healthcare seeking among the urban residents is critical in identifying appropriate interventions strategies.The study evaluates determinants of inequality in health care seeking for childhood illnesses among informal settlement residents in Nairobi,Kenya.Methods:Data from the second Nairobi Cross-Sectional Slum Survey(NCSS 2012)was examined.The inequality in seeking health care for childhood diarrhea as the prototype illness was assessed using concentration index(CI).The wealth index based on the household possessions and amenities was used as a measure for socioeconomic status.Results:A total of 2027 qualified women were included in this study.About 16.6% of children born of younger mothers aged<20 years had diarrhea and a similar proportion of children(16.3%)was observed among mothers who were unemployed.The CI of-0.026 on health care seeking for diarrhea among children points to significant inequality among the urban poor(95% confidence interval:-0.028 to-0.023).Conclusion:Occupation of parents,age of mothers,ethnicity,marital status and children's age were major deter-minants with regard to disease outcome and to a broader extent inequality in health care seeking for childhood illnesses.Enhanced bottom top community health invigoration strategies in health information awareness and services access would be instrumental.

Environmental determinants of access to shared sanitation in informal settlements:a cross-sectional study in Abidjan and Nairobi

Background Universal access to basic sanitation remains a global challenge,particularly in low-and middle-income countries.Efforts are underway to improve access to sanitation in informal settlements,often through shared facilities.However,access to these facilities and their potential health gains—notably,the prevention of diarrheal diseases—may be hampered by contextual aspects related to the physical environment.This study explored associations between the built environment and perceived safety to access toilets,and associations between the latter and diarrheal infections.Methods A cross-sectional study was carried out between July 2021 and February 2022,including 1714 households in two informal settlements in Abidjan(Côte d’Ivoire)and two in Nairobi(Kenya).We employed adjusted odds ratios(aORs)obtained from multiple logistic regressions(MLRs)to test whether the location of the most frequently used toilet was associated with a perceived lack of safety to use the facility at any time,and whether this perceived insecurity was associated with a higher risk of diarrhea.The MLRs included several exposure and control variables,being stratified by city and age groups.We employed bivariate logistic regressions to test whether the perceived insecurity was associated with settlement morphology indicators derived from the built environment.Results Using a toilet outside the premises was associated with a perceived insecurity both in Abidjan[aOR=3.14,95%confidence interval(CI):1.13–8.70]and in Nairobi(aOR=57.97,95%CI:35.93–93.53).Perceived insecurity to access toilets was associated with diarrheal infections in the general population(aOR=1.90,95%CI:1.29–2.79 in Abidjan,aOR=1.69,95%CI:1.22–2.34 in Nairobi),but not in children below the age of 5 years.Several settlement morphology features were associated with perceived insecurity,namely,buildings’compactness,the proportion of occupied land,and angular deviation between neighboring structures.Conclusions Toilet location was a critical determinant of perceived security,and hence,must be adequately addressed when building new facilities.The sole availability of facilities may be insufficient to prevent diarrheal infections.People must also be safe to use them.Further attention should be directed toward how the built environment affects safety.

Impact of urban upgrading on perceptions of safety in informal settlements： Case study of Bouakal, Batna

This paper explores how modifications of urban space in informal settlements influence residents＇ quality of life and perceptions of safety. This is a case study of Bouakal, the oldest informal district in Batna, a middle city in Algeria. This paper examines the effects of urban improvement practices in Bouakal by exploring two questions： In what ways did interventions in this informal settlement affect the quality of life for the residents？ How do these effects correlate with changes in the perception of safety in this area？ The survey involved 141 residents from Bouakal, and local residents were selected to collect the levels of perceived safety. This paper concludes that urban upgrading has improved the quality of tile and has a positive effect on the perception of safety in the settlement.

Using open data to detect the structure and pattern of informal settlements:an outset to support inclusive SDGs’achievement

The detection of informal settlements is the first step in planning and upgrading deprived areas in order to leave no one behind in SDGs.Very High-Resolution satellite images(VHR),have been extensively used for this purpose.However,as a cost-prohibitive data source,VHR might not be available to all,particularly nations that are home to many informal settlements.This study examines the application of open and freely available data sources to detect the structure and pattern of informal settlements.Here,in a case study of Jakarta,Indonesia,Medium Resolution satellite imagery(MR)derived from Landsat 8(2020)was classified to detect these settlements.The classification was done using Random Forest(RF)classifier through two complementary approaches to develop the training set.In the first approach,available survey data sets(Jakarta’s informal settlements map for 2015)and visual interpreta-tion using High-Resolution Google Map imagery have been used to build the training set.Throughout the second round of classifica-tion,OpenStreetMap(OSM)layers were used as the complementary approach for training.Results from the validation test for the second round revealed better accuracy and precision in classi-fication.The proposed method provides an opportunity to use open data for informal settlements detection,when:1)more expen-sive high resolution data sources are not accessible;2)the area of interest is not larger than a city;and 3)the physical characteristics of the settlements differ significantly from their surrounding formal area.The method presents the application of globally accessible data to help the achievement of resilience and SDGs in informal settlements.

Escherichia coli Pathotypes in Children with Acute Diarrhea in an Informal Settlement in Nairobi, Kenya

Diarrhea is among the leading causes of morbidity and mortality in children aged Escherichia coli (DEC) accounts for 30% - 40% of childhood diarrhea cases. To identify the pathotypes involved in diarrheal outbreaks in Kenya, we analyzed archived E. coli isolates from children E. coli confirmation and antimicrobial susceptibility testing were done using the VITEK®2 instrument. Pathotype identification was performed via conventional polymerase chain reaction. Of 175 E. coli isolates, 48 (27%) were DEC pathotypes, with enteroaggregative E. coli (EAEC) predominating (71%, 34/48). Enterohemorrhagic (EHEC) and enteropathogenic E. coli (EPEC) represented 19% and 10% of isolates, respectively. Enteroinvasive and enterotoxigenic pathotypes were not identified. All DEC isolates were susceptible to amikacin, ertapenem, imipenem, meropenem and tigecycline. Conversely, most (>80%) isolates were resistant to ampicillin, ampicillin-sulbactam and sulfamethoxazole-trimethoprim. Half of all EAEC and EPEC strains were resistant to cefazolin while half of EHEC isolates were resistant to ciprofloxacin and moxifloxacin. In total, 18 resistance phenotypes were identified with “ampicillin-cefazolin-ampicillin/ sulbactam-sulfamethoxazole/trimethoprim” predominating (33%, 16/48). The majority (81%) of DEC isolates were multidrug-resistant, with extended-spectrum beta-lactamase production identified in 8% of these isolates. This study highlights the predominance of Enteroaggregative E. coli and multidrug resistance of DEC pathotypes. Studying the epidemiology of diarrheal disease and antimicrobial resistance surveillance, will aid in identifying dominant etiological agents of diarrhea and newly emerging resistant strains in informal settlements.

Metropolitan Housing Development in Urban Fringe Areas-A Case Study of Three Metropolitan Cities of South Africa: Johannesburg, Ekurhuleni and Tshwane

Purpose:The metropolitan cities of Johannesburg,Ekurhuleni and Tshwane play an important role in the economy of the Gauteng province in South Africa.The region constitutes to 22.4 percent of the total population of South Africa and has a strong presence and contributes in areas of manufacturing sector,financial and business services,retail and wholesale trade,etc.The rapid urban population,increase in the informal settlements and socio-economic opportunities has resulted in considerable urban sprawl in and around the urban fringe areas of these metropolitan cities.The urban fringe areas of these metros often come under the influence of rapid urbanization process and pressures.Coupled with the economical and potential land dynamics and lack of priority of spatial development guidelines,these areas attract rapid and haphazard development from communities and developers.Research Design/Methodology:This research is based on a qualitative approach through a comprehensive literature review that included content analysis of key documents on housing sector such as IDPs(Integrated Development Plans),Municipal Annual Reports,Growth Development Strategies,and among other sectoral documents on housing sector.Some of the key priority issues considered in the housing sector included:eradication of housing backlogs,spatial restructuring of housing,provision of choice in terms of location,tenure and housing typology.Findings:The current paper discusses the approaches of metropolitan housing development processes in three metropolitan cities of South Africa from Gauteng region,namely:Johannesburg,Ekurhuleni and Tshwane.The paper discusses the existing housing sectoral scenario along with the fringe areas in three cities with focus on:formal and informal settlements,housing segregation and the backlogs,current institutional arrangements,role of public private participation,and scope for alternate mechanisms.The paper concludes in discussion on sustainable development options for housing development in urban fringe areas.

Trend of <i>Cryptosporidium</i>Infection among Children below 24 Months in an Informal Urban Settlement, Kenya

Cryptosporidium infection is estimated to cause 2.9 million diarrheal cases yearly among children aged under 24 months in sub-Saharan Africa. Studies have shown long-term climatic variations can affect infectious diseases. The burden of cryptosporidiosis in rural areas of sub-Saharan Africa is well characterized. However, the trend of Cryptosporidium infection is not known, especially in informal urban settings. This study therefore sought to determine cryptosporidiosis trends, and further explore the association between year and Cryptosporidium infection among children below 24 months in Kibera urban informal settlement in Kenya. Data collected by the Kenya Medical Research Institute longitudinal study in Tabitha clinic in Kibera from 2009 to 2015 were used. At least 3000 children aged < 24 months receive free health care at the clinic. In the longitudinal study, children presenting with diarrhea were eligible for stool sample collection (n = 477), out of which 421 stool samples were tested using TaqMan™ Array Card (TAC) polymerase chain reaction panel that included a target for Cryptosporidium genus. Data for the 421 children were included in the analysis. Logistic regression was used to explore the difference between the seven years and cryptosporidiosis. Overall, the pooled data indicated that 23.5% of the children who were tested had Cryptosporidium infection, with the highest proportions of Cryptosporidium-positive cases observed in 2015 (45.2%). The logistic regression results also indicated that children who were tested in the year 2015 were more likely to have Cryptosporidium infection (OR = 3.39;95% CI: 1.44 - 7.96;p = 0.005) than those in 2009. Watery stool was also found to be an important symptom of cryptosporidiosis. There was a high prevalence of Cryptosporidium infection among young children, especially in the most recent year. Routine testing of Cryptosporidium infection using molecular methods, constant monitoring and identification of the infection sources is therefore necessary towards reducing the disease burden in the low resource settings.

Super-resolution GANs for upscaling unplanned urban settlements from remote sensing satellite imagery - the case of Chinese urban village detection

The semantic segmentation of informal urban settlements represents an essential contribution towards renovation strategies and reconstruction plans.In this context,however,a big challenge remains unsolved when dealing with incomplete data acquisitions from multiple sensing devices,especially when study areas are depicted by images of different resolutions.In practice,traditional methodologies are directed to downgrade the higher-resolution data to the lowest-resolution measure,to define an overall homogeneous dataset,which is however ineffective in downstream segmentation activities of such crowded unplanned urban environments.To this purpose,we hereby tackle the problem in the opposite direction,namely upscaling the lower-resolution data to the highest-resolution measure,contributing to assess the use of cutting-edge super-resolution generative adversarial network(SR-GAN)architectures.The experimental novelty targets the particular case involving the automatic detection of‘urban villages’,sign of the quick transformation of Chinese urban environments.By aligning image resolutions from two different data sources(Gaofen-2 and Sentinel-2 data),we evaluated the degree of improvement with regard to pixel-based landcover segmentation,achieving,on a 1 m resolution target,classification accuracies up to 83%,67%and 56%for 4x,8x,and 10x resolution upgrades respectively,disclosing the advantages of artificially-upscaled images for segmenting detailed characteristics of informal settlements.

The Effect of Regional Socio-Economic Factor on Development of Heterogeneous Urban Contexts;Case Study: Bandar Abbas City

Heterogeneous urban development of Iran during current decades along with ineffectiveness of urban planning system and shortcoming of national development programs and land use planning have led to many problems of urbanism in Iran so that heterogeneous and old contexts can be named as one of the problems in this field. Urban decay is one of the serious and inevitable problems of urban management in all countries. This study has been conducted to analyze and assess the effect of regional factors on development of problematic urban contexts emphasizing on socio- economic indicators in Bandar Abbas City. Having urban macro-indicators at regional and country level, Bandar Abbas City faces various physical problems which problematic and old contexts are the most important of them that cover an area of 1033 hectares. Economic issues and heterogeneity within social contexts have expanded the mentioned problem in addition to physical problems. Methodology of this study has been analytical-descriptive, data collection method of documentary information has been gathered from relevant administrative organization such as Statistical Center of Iran, the Municipality and the Ministry of Housing and Urban Development, and survey data has been collected through 90 questionnaires. According to the obtained results of this study, it could be found that social, economic, political and managerial factors have had effects on formation of heterogeneous contexts and extensive migration during the current years has expanded problematic contexts of Bandar Abbas due to its specific regional conditions. Moreover, the obtained results of this study indicated that heterogeneous contexts had some features including fine-grained, inadequate access network, impervious, inferior materials and poor construction of buildings and lack of necessary infrastructure.

Mobile GIS occupancy audit of Ulana informal settlement in Ekurhuleni municipality, South Africa

Relocating people in informal settlements and upgrading the lives of those people requireconsistent commitment, good strategies, and supporting systems. In South Africa, in order toallocate subsidized housing to beneficiaries of an informal settlement, beneficiary administration needs to determine the number of people who qualify for subsidized houses. Withoutgeo-spatial data-based technical verification, conventional methods of occupancy audits areoften cumbersome, are unreliable, and do not promote smart and evidence-based decisionmaking. Accordingly, the aim of this study is to propose and develop an Oracle-based mobileGIS tool to conduct an occupancy audit for Ulana, an informal settlement in EkurhuleniMunicipality in South Africa. Android-based tablets were used to collect the geographicand socio-economic attributes of the informal dwelling units (DU). Spatial analysis (inArcGIS software and geo-spatial modeling environment) and statistical analysis were conducted to produce the occupancy audit. The results indicated that the use of mobile GISprovides up-to-date, accurate, comprehensive, and real-time data so as to facilitate thedevelopment of smart and integrated human settlements. The results of this audit alsoindicated that only 57% of the households residing in Ulana could potentially benefit fromreceiving a subsidized house. Accordingly, the occupancy audit enables planners to planappropriate upgrading and housing development strategies for informal settlement. Thisstudy demonstrates that successful planning of housing delivery for post independentintegrated neighborhoods is not a mere political rhetoric but is viable when it is based onreasonable geo-spatial techniques and information. The use of mobile GIS therefore needs tobe extended to other informal settlement upgrading projects in South Africa as well as othercities in the global south. However, proper professional training is required to ensure thesuccessful usage of smart mobile GIS tools.

Perception of Disasters and Land Reclamation in an Informal Settlement on Reclaimed Land:Case of the BASECO Compound,Manila,the Philippines

Southeast Asia's coastal urban areas continue to grow,with land reclamation fast becoming an important option for megacities to address issues of economic growth and increasing population density.Experts are divided over the advantages and disadvantages of land reclamation,though this process continues unabated,exposing settlements to coastal hazards.The Bataan Shipping and Engineering Company(BASECO)compound is an informal settlement on reclaimed land in Manila,the Philippines.How informal coastal settlements view disaster risk and their more pressing socioeconomic needs is crucial to understanding the potentials and repercussions of land reclamation.Using a topographic survey,a questionnaire survey,and the protective action decision model,this study explored the perception of disasters and land reclamation of informal settlers who are living on reclaimed land.The study found that people are aware of disaster risks,but are more concerned with everyday needs.They are divided on the issue of further land reclamation.Residents on the original non-reclaimed land view it as a coastal defense,while those on reclaimed land fear potential eviction.Despite this,all locations in the community are concerned with the loss of jobs,economic opportunities,and eviction,rather than potential disasters.

Does Tenure Security Reduce Disaster Risk? A Comparative Study of the Nairobi Settlements of Kibera and Kawangware

While scholarship suggests that improving tenure security and housing significantly reduces disaster risk at the household level within urban settings,this assertion has not been adequately tested.Tenure security can be conceived as being composed of three interrelated and overlapping forms:tenure security as determined by legal systems;de facto tenure security;and tenure security as perceived by residents.This article traces the relationship between tenure security,the quality of housing,and disaster risk on the basis of a mixed methods comparative case study of the settlements of Kawangware and Kibera in Nairobi.Although the findings suggest that owner-occupancy is associated with the structural integrity of dwellings to a greater extent than tenantship,no association was found between the length of occupancy by households and the structural integrity of the dwelling.Moreover,tenantship is not found to be closely associated with fires and flooding affecting the dwelling as extant scholarship would suggest.Formal ownership is linked with greater investment and upgrading of property with significant implications for disaster risk.Our findings highlight the complex relationship between tenure security and disaster risk in urban informal settlements and provide impetus for further investigation.

From Redevelopment to In Situ Upgrading: Transforming Urban Village Governance in Shenzhen Through the Lens of Informality

The study on informality has experienced a shift from describing the spatial characteristics toward exploring the connotation of urban governance in recent years. This paper takes urban villages in Shenzhen, a typical informal settlement in China, as cases to analyze the two urban village governance modes of redevelopment and in situ upgrading and reveals the dynamics of the governance mode transformation. Through the lens of informality, this study focuses on the interaction among the government, the market, and former property owners on tenure legalization. The study finds that first of all, informality is the core of the transformation of urban village governance in Shenzhen. By strategically making use of informality, the government adopted different modes of urban village governance to fulfill the demands of urban development at different phases. Second, in the process of formalizing informal settlements through redevelopment, although the institutional framework is relatively complete, the boundary between informality and formality still changes continuously in property titling. While in the new governance mode of in situ upgrading in recent years, the government creates "special areas" in informal settlements via approving their de facto tenure security, so as to attract market force to upgrade physical environment and social management. Through revealing the mechanism in the blurred area between informality and formality, this paper responds to the dualistic argument on the informality theory, deepens the idea of taking informality as a flexible urban governance strategy in developing countries, and provides new thoughts for governance of informal settlements in China and other developing countries.

Mapping informal settlement indicators using object-oriented analysis in the Middle East

Mapping informal settlements is crucial for resource and utility management and planning.In 2003,the UN-Habitat developed a process for mapping and monitoring urban inequality to support reporting against the sustainable development goals(SDGs).Informal settlement indicators are used as a framework to carry out image analysis,and include vegetation extent,lacunarity of housing structures/vacant land,road segment type and materials,texture measures of built-up areas,roofing extent of built-up areas and dwelling size.Objectbased image analysis(OBIA)methods are recommended to identify informal settlements.This paper documents the application of OBIA to map informal settlements,drawing on the ontology of Kohli et al.(2012)and the indicators of Owen and Wong(2013)for a Middle Eastern city.Three informal settlements with different land use histories were selected to represent old and new informal settlements in the city of Jeddah,Saudi Arabia.Vegetation extent was the most successful indicator detected,with 100% producer accuracy and over 84% user accuracy,followed by the road network,with 84% producer and user accuracies in older informal settlements and 73% producer accuracy and 96% user accuracy across all case studies.Lacunarity of housing structures/vacant land was detected well in informal settlements.The texture measure indicator was detected using GLCM_(Ent)(R)with low producer accuracy across all case studies.The roofing extent of the built-up area is detected with better producer and user accuracies than texture measures.The dwellings size indicator generally failed to distinguish formal from informal settlements.Informal and formal were distinguished with an overall accuracy of 83%.This research concludes that OBIA is a useful method to map informal settlement indicators in Middle Eastern cities.However,a generic ruleset for mapping informal settlements remains elusive,and each indicator requires significant localised‘tuning’.

A qualitative assessment of solid waste management in Peleng township in Lobatse,Botswana considering spatial aspects

Even though solid waste management is widely researched,there is scanty literature addressing the influence of physical environmental attributes on solid waste management service provision in informal settlements.The aim of this study was to investigate the nexus between physical infrastructural planning and waste management service.To obtain relevant results,this study used the case study of Peleng township in Botswana.The study relied on empirical data collected from 91 ran-domly selected households.ArcGIS was used for mapping 550 purposively selected households,and for visualization of the physical infrastructure.This study concluded that the community is at the forefront of dealing with waste problems in their settlement.However,their interventions have fallen short of becoming profitable and sustainable due to a failure of the government to integrate solid waste management into mainstream urban development planning.The findings revealed that there is minimal government intervention for improved solid waste management in the area.It recommends that adequate attention must be given to road infrastructure and physical developments in order solid waste management in Peleng,Lobatse.