Large Urban Regions Research Articles

Tackling hospital service burden of alcohol dependence in England: a service evaluation of alcohol care teams (ACTs) and care pathways for integrated care

Background Chronic alcohol disorder hospital admissions are increasing in England and present a huge cost to England’s health and social care costs. Hospital-based alcohol care teams (ACTs) aim to better meet these patients’ complex needs through assessment and targeted referral. This has the potential to work effectively within England’s newly established integrated care system. Methods The aim of this project was to identify in what ways ACTs can be effective in improving care pathways for complex care in a whole-system health and social care setting. We conducted semi-structured, tailored interviews with practitioners, managers and commissioners, across three hospital and community settings in one large urban region in England, comparing ACT working with non-ACT working. Results Effective pathways were enabled by the presence of an ACT, multi-agency community initiatives, assertive alcohol outreach and frequent-attender team meetings. Identified barriers were lack of systemic funding and commissioning, poor communication between agencies, lack of information-sharing and insufficient staff training. Conclusion Community outreach and in-reach between hospitals and community services enable effective care pathways when ACTs provide the point of contact. A well-resourced ACT with clear operational remit can create links between diverse agencies and enables improved wraparound care for alcohol dependent patients.

Frog hepatic health and metal pollution: An assemblage-level approach in a hotspot in southeastern Brazil.

Chemical pollutants include the harmful effects of various substances on soils, water bodies, and biodiversity. Amphibians are one of the most endangered groups ofvertebrates and are impacted by chemical pollutants in various ways due to their complex life cycles. Since trace pollutant concentrations vary across environments, different frog ecomorphs (classified by their microhabitat use) may have different exposures. We aimed to determine the association between frog ecomorphs and the occurrence of histopathological hepatic lesions (HHLs) as an indicator of contaminant exposure. We focused on small forest streams near a large urban region in Brazil, heavily polluted in the 1980s. We examined 104 frog specimens from various families. All specimens exhibited HHLs, with melanomacrophages being the most common (n = 99). Arboreal frogs exhibited more vascular congestion, while terrestrial frogs showed structural hepatic damage. Higher cobalt levels were linked to increased liver necrosis in arboreal frogs and structural issues in both arboreal and terrestrial frogs. Cadmium was associated with hepatitis in terrestrial frogs. Although metal levels had no significant effects on rheophilic frogs, the prevalence of hepatitis and necrosis indicated complex exposure pathways. Iron and aluminum were linked to fewer lesions in rheophilic frogs, suggesting resilience. The high prevalence of HHLs signals an ongoing issue, with variations among ecomorphs suggesting differential exposure to pollutantsand posinga complex challenge for community conservation.

Severe Invasive Pneumococcal Disease Caused by Serotype 19A in Children Under Five Years in Tāmaki Makaurau Auckland, Aotearoa New Zealand.

Increases in childhood invasive pneumococcal disease (IPD) have been reported in several countries following the easing of COVID-19 pandemic mitigations. In Aotearoa New Zealand (AoNZ), a surge in IPD is occurring in young children concurrent with changes in pneumococcal vaccines and declining immunization coverage. We sought to examine epidemiologic and clinical features of IPD among children under 5 years in a large urban region of AoNZ in the 3 years post-COVID-19. Demographic, clinical and laboratory data were collated from children under 5 years with Streptococcus pneumoniae identified from normally sterile sites between January 1, 2021, and December 31, 2023, in Tāmaki Makaurau Auckland, AoNZ. We identified 93 episodes of IPD (annual incidence of 18-40 cases per 100,000 population per year). Serotype was identified in 68 episodes and 46 (68%) were serotype 19A. Incidence was higher in Pacific children compared with non-Māori, non-Pacific children (incidence rate ratio: 2.3; 95% confidence interval: 1.4-3.7). Bacteremia occurred in 65 (70%) episodes, empyema in 47 (51%), meningitis in 11 (12%) and hemolytic uremic syndrome in 7 (7.5%). All cases of hemolytic uremic syndrome and empyema were only among children with serotype 19A. Two children died, both had serotype 19A, and 13/91 survivors (14%) experienced serious sequelae. The use of the pneumococcal conjugate vaccine with lower valency and easing of COVID-19 containment measures each may have contributed to an increase in IPD in AoNZ. Serotype 19A is associated with empyema and causes severe disease in young children. Urgent efforts are required to improve PCV13 coverage in AoNZ.

Riding transit to parks in Utah: Motivations, constraints, negotiations, and policy recommendations

In this paper, we studied the motivations, constraints, negotiations, and policy changes for riding transit to parks in Utah’s Wasatch Front region, exploring how these factors vary between disadvantaged and non-disadvantaged individuals. This is one of the first studies to explore transit-to-parks experiences in large urban regions. We conducted interviews with 25 diverse transit riders. Motivations for riding transit to parks included environmental concerns and the convenience of avoiding parking and traffic. Constraints involved excessive travel time due to limited service, transit frequency and reliability issues, and last-mile connection issues. The main negotiation strategy was to plan trips to limit travel time. People in low-income neighborhoods had limited transit-to-parks services, and available services were adequate for fit and non-disabled people. Policy changes that would help participants address constraints included new or modified routes, improved last-mile connections, information and marketing campaigns, and better service for low-income communities and people with disabilities.

Regional differences in heart failure risk in the United Kingdom are partially explained by biological aging.

Heart failure (HF) risk is greater in rural versus urban regions in the United States (US), potentially due to differences in healthcare coverage and access. Whether this excess risk applies to countries with universal healthcare is unclear and the underlying biological mechanisms are unknown. In the prospective United Kingdom (UK) Biobank, we investigated urban-rural regional differences in HF risk and the mechanistic role of biological aging. Multivariable Cox regression was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of incident HF in relation to residential urban-rural region and a Biological Health Score (BHS) that reflects biological aging from environmental, social, or dietary stressors. We estimated the proportion of the total effect of urban-rural region on HF mediated through BHS. Among 417,441 European participants, 10,332 incident HF cases were diagnosed during the follow-up. Compared to participants in large urban regions of Scotland, those in England/Wales had significantly increased HF risk (smaller urban: HR = 1.83, 95%CI: 1.64-2.03; suburban: HR = 1.77, 95%CI: 1.56-2.01; very rural: HR = 1.61, 95%CI: 1.39-1.85). Additionally, we found a dose-response relationship between increased biological aging and HF risk (HRper 1 SD increase = 1.14 (95%CI: 1.12-1.17). Increased biological aging mediated a notable 6.6% (p < 0.001) of the total effect of urban-rural region on HF. Despite universal healthcare in the UK, disparities in HF risk by region were observed and may be partly explained by environmental, social, or dietary factors related to biological aging. Our study contributes to precision public health by informing potential biological targets for intervention.

Latinas in the United States Facing Healthcare Access Challenges in a Mid-Size Urban Community

This study examines the discrepancies and underlying factors in access to healthcare resources regarding breast and cervical cancer for Latinas in a mid-sized urban midwestern community. A survey was conducted at clinics hosted by a local non-profit organization, and forty participants completed surveys for this study (n=40). Bivariate correlation analysis in SPSS determined that significant positive correlations were found between the subjects’ knowledge of the signs and symptoms of cervical cancer and their knowledge of the recommended frequency of receiving pap smears (p&lt;0.01). Additionally, significant positive correlations were found between whether a subject had a primary care physician and their awareness of the resources available to them regarding breast and cervical cancer (p&lt;0.01). Also, this study suggests that existing discrepancies in critical healthcare screening exist within the targeted community and are similar or worse than findings from larger urban regions throughout the US.

One size doesn't fit all: methodological reflections in conducting community-based behavioural science research to tailor COVID-19 vaccination initiatives for public health priority populations.

Promoting the uptake of vaccination for infectious diseases such as COVID-19 remains a global challenge, necessitating collaborative efforts between public health units (PHUs) and communities. Applied behavioural science can play a crucial role in supporting PHUs' response by providing insights into human behaviour and informing tailored strategies to enhance vaccination uptake. Community engagement can help broaden the reach of behavioural science research by involving a more diverse range of populations and ensuring that strategies better represent the needs of specific communities. We developed and applied an approach to conducting community-based behavioural science research with ethnically and socioeconomically diverse populations to guide PHUs in tailoring their strategies to promote COVID-19 vaccination. This paper presents the community engagement methodology and the lessons learned in applying the methodology. The community engagement methodology was developed based on integrated knowledge translation (iKT) and community-based participatory research (CBPR) principles. The study involved collaboration with PHUs and local communities in Ontario, Canada to identify priority groups for COVID-19 vaccination, understand factors influencing vaccine uptake and co-design strategies tailored to each community to promote vaccination. Community engagement was conducted across three large urban regions with individuals from Eastern European communities, African, Black, and Caribbean communities and low socioeconomic neighbourhoods. We developed and applied a seven-step methodology for conducting community-based behavioural science research: (1) aligning goals with system-level partners; (2) engaging with PHUs to understand priorities; (3) understanding community strengths and dynamics; (4) building relationships with each community; (5) establishing partnerships (community advisory groups); (6) involving community members in the research process; and (7) feeding back and interpreting research findings. Research partnerships were successfully established with members of prioritized communities, enabling recruitment of participants for theory-informed behavioural science interviews, interpretation of findings, and co-design of targeted recommendations for each PHU to improve COVID-19 vaccination uptake. Lessons learned include the importance of cultural sensitivity and awareness of sociopolitical context in tailoring community engagement, being agile to address the diverse and evolving priorities of PHUs, and building trust to achieve effective community engagement. Effective community engagement in behavioural science research can lead to more inclusive and representative research. The community engagement approach developed and applied in this study acknowledges the diversity of communities, recognizes the central role of PHUs, and can help in addressing complex public health challenges.

Spatio-temporal epidemiology and associated indicators of COVID-19 (wave-I and II) in India

The spatio-temporal distribution of COVID-19 across India’s states and union territories is not uniform, and the reasons for the heterogeneous spread are unclear. Identifying the space–time trends and underlying indicators influencing COVID-19 epidemiology at micro-administrative units (districts) will help guide public health strategies. The district-wise daily COVID-19 data of cases and deaths from February 2020 to August 2021 (COVID-19 waves-I and II) for the entire country were downloaded and curated from public databases. The COVID-19 data normalized with the projected population (2020) and used for space–time trend analysis shows the states/districts in southern India are the worst hit. Coastal districts and districts adjoining large urban regions of Mumbai, Chennai, Bengaluru, Goa, and New Delhi experienced > 50,001 cases per million population. Negative binomial regression analysis with 21 independent variables (identified through multicollinearity analysis, with VIF < 10) covering demography, socio-economic status, environment, and health was carried out for wave-I, wave-II, and total (wave-I and wave-II) cases and deaths. It shows wealth index, derived from household amenities datasets, has a high positive risk ratio (RR) with COVID-19 cases (RR: 3.577; 95% CI: 2.062–6.205) and deaths (RR: 2.477; 95% CI: 1.361–4.506) across the districts. Furthermore, socio-economic factors such as literacy rate, health services, other workers’ rate, alcohol use in men, tobacco use in women, overweight/obese women, and rainfall have a positive RR and are significantly associated with COVID-19 cases/deaths at the district level. These positively associated variables are highly interconnected in COVID-19 hotspot districts. Among these, the wealth index, literacy rate, and health services, the key indices of socio-economic development within a state, are some of the significant indicators associated with COVID-19 epidemiology in India. The identification of district-level space–time trends and indicators associated with COVID-19 would help policymakers devise strategies and guidelines during public health emergencies.

Water scarcity challenges across urban regions with expanding irrigation

Irrigation expansion is often posed as a promising option to enhance food security. Here, we assess the influence of expansion of irrigation, primarily in rural areas of the contiguous United States (CONUS), on the intensification and spatial proliferation of freshwater scarcity. Results show rain-fed to irrigation-fed (RFtoIF) transition will result in an additional 169.6 million hectares or 22% of the total CONUS land area facing moderate or severe water scarcity. Analysis of just the 53 large urban clusters with 146 million residents shows that the transition will result in 97 million urban population facing water scarcity for at least one month per year on average versus 82 million before the irrigation expansion. Notably, none of the six large urban regions facing an increase in scarcity with RFtoIF transition are located in arid regions in part because the magnitude of impact is dependent on multiple factors including local water demand, abstractions in the river upstream, and the buffering capacity of ancillary water sources to cities. For these reasons, areas with higher population and industrialization also generally experience a relatively smaller change in scarcity than regions with lower water demand. While the exact magnitude of impacts are subject to simulation uncertainties despite efforts to exercise due diligence, the study unambiguously underscores the need for strategies aimed at boosting crop productivity to incorporate the effects on water availability throughout the entire extent of the flow networks, instead of solely focusing on the local level. The results further highlight that if irrigation expansion is poorly managed, it may increase urban water scarcity, thus also possibly increasing the likelihood of water conflict between urban and rural areas.

All talk…only a little action: a reflection on embedding equity into integrated care models in Ontario, Canada

Background: Ontario Health Teams (OHTs) are a recently introduced model of delivery intended to integrate services to deliver connected care to defined populations in Ontario, Canada. The Quadruple Aim advocates for improving patient experience, reducing cost, advancing population health, and improving the provider experience; it is meant to be a guide for OHTs for performance outcomes and as a framework for evaluation and reporting. The Quintuple Aim, incorporating an added focus on health equity, has recently been introduced to OHTs, where equity is also built into continuous quality improvement requirements. As embedded OHT research fellows, we recognize our key role in supporting equity in healthcare delivery and programs. However, we also observe the challenges to generating actionable initiatives to integrate equity into OHTs.&#x0D; Objective: The objective of this presentation is to describe equity initiatives being incorporated in four OHTs in Ontario, Canada and to identify the barriers and facilitators at the micro, meso and macro levels. This presentation is aimed at those involved in integrated care research, policy, practice, and education.&#x0D; Methods: We will use a multiple case study design to describe the contexts of four integrated care models representing large, mid, and small urban regions of the province. This work is guided by the Rainbow Model for Integrated Care, which conceptualizes different domains of integrated care. We will include multiple data sources from each OHT, including key documents, formal and informal community partnerships, the level and nature of engagement with equity-deserving groups in governance processes, the extent to which equity is emphasized in strategic plans and other documents, and the resources available, we share insights gleaned on barriers and facilitators to applying an equity lens. &#x0D; Key Results: We identify challenges related to data availability for health equity decision making and health systems planning. Specifically, difficulties exist in accessing meaningful and linked data to understand OHT attributed populations; these difficulties are compounded when seeking data specific to equity deserving groups and when attempting to link equity relevant indicators to health system indicators. Furthermore, meaningful engagement with equity deserving groups in order to build relationships requires time and resources that are difficult to source; such engagement is particularly challenging in an environment of limited financial resources, where frequent reporting and pressure to quickly deliver outcomes is emphasized. OHTs are collaborative governance models composed of representation from member organizations, patients, and academics; this collaborative approach to governance can be a facilitator to embedding equity deserving groups into the structure of OHTs.&#x0D; Next Steps: Ontario Health Teams require support in creating comprehensive equity approaches that are specific to the needs of their communities and teams; further work is needed to better understand the needs of OHTs in this regard.

Modelling future wetland loss with land use landcover change simulation in the Greater Toronto and Hamilton Area: The importance of continued greenbelt development restrictions

The Greater Toronto and Hamilton Area (GTHA) is both the largest urban region in Canada and an area that contains most of the Greenbelt, a protected, ecologically significant area. This study uses land use landcover (LULC) change simulation and wetland data to model how increasing urban and suburban expansion may influence wetland loss and fragmentation in the GTHA if Greenbelt restrictions are not upheld. The results of the model simulation show that; (1) built-up area expansion shifts from the perimeters of major cities to the perimeters of smaller urban communities in the coming decades; (2) built-up areas are the LULC classification associated with substantially more wetland loss than the other LULC classifications included in this study (agriculture, forest, or open range land); (3) rural areas in the northern GTHA experience more wetland raster cell transition and urban areas experience fragmentation, but less overall raster cell transition; (4) there is more wetland area in Greenbelt areas compared to non-Greenbelt areas and without the continued enforcement of development restrictions, the percentage of wetland raster cell transition in Greenbelt areas would be equal to non-Greenbelt areas. This study illustrates the ecological significance of the policy frameworks that uphold the Greenbelt development restrictions and highlights how untethered urban and suburban expansion could impact wetlands throughout this environmentally sensitive region.

Does urban polycentricity contribute to regional economic growth? Empirical evidence from a panel of Chinese urban regions

ABSTRACT Research examining the economic effects of urban polycentricity remains inconclusive. We contribute to this debate by developing a longitudinal framework in which changes in polycentricity in Chinese urban regions are linked with changes in total factor productivity. While we find no evidence of urban polycentricity being conducive to economic growth, we observe that the relationship depends on population size and the interactions between cities. We also find that cities borrow size from nearby cities in large urban regions, contributing to regional economic growth. We use our findings to reflect on China’s regional economic and urban development strategies.

Spatial self-identification of communes in urban region as an important perspective for shaping a metropolitan area

Motives: The main manifestation of suburbanisation, which is crucial process shaping settlement system in Poland, are suburbs, whose spatial expansion and qualitative characteristics lead to the formation of new functional and spatial structures between the central city and its surroundings. In this sense, the process of suburbanisation is closely related to metropolisation, i.e. the growing importance in the economy of large urban regions or, more broadly, urbanised systems.Aim: The purpose of this study is to trace the spatial policy of the communes making up the Bydgoszcz–Toruń Metropolitan Area (BTMA) concerning entries in their strategic and planning documents indicating the degree of metropolitan links.Results: It was shown that these records would determine further actions affecting the advancement of the metropolisation process in urban region of Kujawsko-Pomorskie Voivodeship. Against the strategic and planning documents background, the vision for the creation of the Bydgoszcz–Toruń Metropolitan Area, present in the narrative of the two major cities, is quite different. It seems it will complicate the metropolisation process in the region.

The after-lives of no arrival: How Papuans make their lives matter

The essay considers heterogeneous Black temporalities in West Papua, Indonesia's largest urban region. Here, "Papuan time" is an extension beyond the dilemmas of being human or not. This is the possibility of being a human that has not experienced irremediable loss or a future foreclosed. But rather an entity that endures an after-life beyond what anyone might know it; a life situated in the middle of freedom and abjection. Such a life takes place in a city, Jayapura, that appears perpetually unsettled, something always “new.” But in the repetition of such newness, it is a city that does not seem to go anywhere specific, that does not promise any sense of redemption. A city that never arrives.

Can we use atmospheric CO2 measurements to verify emission trends reported by cities? Lessons from a 6-year atmospheric inversion over Paris

Abstract. Existing CO2 emissions reported by city inventories usually lag in real-time by a year or more and are prone to large uncertainties. This study responds to the growing need for timely and precise estimation of urban CO2 emissions to support present and future mitigation measures and policies. We focus on the Paris metropolitan area, the largest urban region in the European Union and the city with the densest atmospheric CO2 observation network in Europe. We performed long-term atmospheric inversions to quantify the citywide CO2 emissions, i.e., fossil fuel as well as biogenic sources and sinks, over 6 years (2016–2021) using a Bayesian inverse modeling system. Our inversion framework benefits from a novel near-real-time hourly fossil fuel CO2 emission inventory (Origins.earth) at 1 km spatial resolution. In addition to the mid-afternoon observations, we attempt to assimilate morning CO2 concentrations based on the ability of the Weather Research and Forecasting model with Chemistry (WRF-Chem) transport model to simulate atmospheric boundary layer dynamics constrained by observed layer heights. Our results show a long-term decreasing trend of around 2 % ± 0.6 % per year in annual CO2 emissions over the Paris region. The impact of the COVID-19 pandemic led to a 13 % ± 1 % reduction in annual fossil fuel CO2 emissions in 2020 with respect to 2019. Subsequently, annual emissions increased by 5.2 % ± 14.2 % from 32.6 ± 2.2 Mt CO2 in 2020 to 34.3 ± 2.3 Mt CO2 in 2021. Based on a combination of up-to-date inventories, high-resolution atmospheric modeling and high-precision observations, our current capacity can deliver near-real-time CO2 emission estimates at the city scale in less than a month, and the results agree within 10 % with independent estimates from multiple city-scale inventories.

Urban Constitutionalism and the Rule of Law: Historical Perspectives and Contemporary Challenges

AbstractThe 21st century may safely be called the ‘urban era’. The year 2007 marked the moment when for the first time in modern history, over 50% of the world’s population lived in urban areas. By the year 2050 almost 70% of humanity is projected to be urban, i.e., a human settlement with usually a high population density and an infrastructure of built environment. While the role of large cities, metropolitan areas and urban regions has been increasing, the political domain of the states, of which these cities or regions constitutionally form part, seems to be continuously shrinking. And although the rise of the urban is unlikely to lead to the disappearance of the sovereign-state model, the idea of states as having final authority is seriously challenged. This is caused by at least two simultaneously occurring trends: the transfer of tasks and responsibilities upwards, to the international and supranational level, through processes of globalization and a development downwards, to the local and regional level (or even the neighborhood or district), through processes of decentralization and regionalization. These combined trends have been called glocalization, a process exemplary for the complexity of modern society, in which authority shifts from hierarchy to networks, and the autonomy and unity of the central and sovereign state are under pressure. This special issue is the fruit of a workshop organized at Tilburg Law School on 25 November 2022, dedicated to the exploration of several constitutional and rule of law challenges posed by what we have dubbed urban constitutionalism.

Associations of neighborhood-level socioeconomic status, accessibility, and quality of green spaces in Finnish urban regions

Ensuring fair access to urban green spaces is a constant challenge for planning in densifying cities. Moreover, the quality of green spaces that determines their usability is often insufficiently considered in accessibility research. We examined residents’ accessibility to different types of green spaces also by neighborhood-level socioeconomic status (SES) in the seven largest urban regions in Finland. We identified eight different green space types, and high and low SES neighborhoods using income, education, and unemployment rate. We calculated network-based accessibility to the different types of green spaces and compared areas with a high and low SES using ANOVA. 90% of the urban residents lived within 300 meters of any green space. However, inclusion of the quality factors decreased accessibility of the green spaces from 34% to 75%. Residents living in high and low SES areas had different quality features in their nearest green spaces. Recreation facilities and routes were closer to low SES areas, whereas areas of high SES were associated with better accessibility to large green areas, and forests. This pattern recurred in most individual cities with varying distance differences. Our results emphasize the importance of considering the quality of green spaces in urban planning.

Extended exergy accounting theory to design waste-to-energy management system under uncertainty

This paper seeks to study the waste-to-energy facility location planning problems under uncertainty from an integrated perspective. The extended exergy accounting method is first used to develop a multi-criteria decision analysis framework that unique in unifying multiple criteria of material, energy, social, economic and environmental aspects into homogeneous exergy terms, thus employing multiple criteria to obtain an integrated decision-making result.Robust optimization and mixed-integer linear programming mathematical techniques are applied to formulate the problem as a two-stage robust waste-to-energy facilities location model based on this framework to minimize the exergy expenditure, and determine the technology type, location and capacity size of waste-to-energy facilities over a large urban region. The uncertainty of municipal solid waste supply quantity in each waste generation site is considered.The proposed model was demonstrated using a case study for household food waste treatment in Shanghai, and two treatment scenarios are proposed. Under the same uncertainty, the deployment strategy in scenario II feeds annual 2,655,140 GJ more equivalent primary exergy into the urban ecosystem than the scenario I, indicating that the only deployed on-site biogas plant to disposal household food waste performs better than the centralized incineration and on-site biogas plant combined deployment.A further sensitivity analysis reveals several valuable insights into municipal solid waste management. If the uncertainty is not considered, it may result in a municipal solid waste treatment capacity gap of up to 11.5% and a waste-to-energy system breakdown. Introducing the uncertain budget and range can help the decision-maker adjust the planning scheme flexibly, but the results become more conservative as their values increase. In this case study, it is optimal for decision makers to choose uncertain range mˆi=12.5% and uncertain budget Γ=30.

An efficient calculation method of large-region dynamic traffic noise maps based on hybrid modeling

The construction of noise maps is of great significance for the management and control of urban noise and the protection of residents’ physical and mental health. The European Noise Directive recommends using computational methods to construct strategic noise maps when possible. The current noise maps based on model calculation rely on complex noise emission and propagation models, and their huge number of regional grids needs to consume a lot of calculation time. This seriously restricts the update efficiency of noise maps, making it difficult to realize large-scale application and real-time dynamic update of noise maps. In order to improve the computational efficiency of noise maps, based on big data-driven technology, this paper combines the traditional CNOSSOS-EU noise emission modeling method with the multivariate nonlinear regression modeling method, and proposes an efficient calculation method of large-region dynamic traffic noise maps based on hybrid modeling method. First, this paper constructs the (daily and nightly) noise contribution prediction models of road sources with different classes, considering the daily and nightly periods and different urban road classes. Parameters of the proposed model are evaluated by using the multivariate nonlinear regression method to replace the complex nonlinear acoustic mechanism modeling. On this basis, in order to further improve the computational efficiency, noise contribution attenuations of the constructed models are parameterized and evaluated quantitatively. And then, the database containing the index table of the road noise sources-receivers and the corresponding noise contribution attenuations is constructed. The experimental results show that compared with the traditional calculation methods based on acoustic mechanism model, the noise map calculation method based on hybrid model proposed in this paper greatly reduces the model computations of noise map, improves the efficiency of noise mapping. It will provide technical support for constructing dynamic noise maps of large urban regions.

Using Sentinel-1 and Google Earth Engine cloud computing for detecting historical flood hazards in tropical urban regions: a case of Dar es Salaam

This study investigates the potential of freely available Sentinel-1 imagery coupled with Google Earth Engine (GEE) for mapping and monitoring flooding in Dar es Salaam. Sentinel-1 images (n = 55) available during the rainy season (March–May) since 2016 were used and processed in GEE. For separating water and land surfaces, we used a histogram-based automatic thresholding method. The binarization accuracy was assessed using confusion matrix based on 1064 randomly generated points in GEE. Overall accuracy of 95% (Kappa = 0.90) were achieved. Dar es Salaam has experienced flood inundation per flood event on average over an area of 50 km2 in March 2019 and 2021. Territories located along the Ocean and inland water shores, built and bare ground were subject to flooding compared to other land cover types. Flooding inundations have been difficult to detect in the city center. With the current temporal and spatial resolution of Sentinel-1, flood detection in city centers remains a challenge yet. However, Sentinel-1 images, coupled with GEE cloud computing simplified flood mapping and monitoring in a large urban region and this approach can be applied in other large cities and their surroundings for countries where data gap and lack of processing tools are critical challenges.