Urban Currents

Integrated assessment of urban heat island vulnerability in the Madurai region, India

This study developed a multi-layer urban heat island vulnerability assessment for the Madurai region in India, analyzing land use changes, decadal water spread area variations from 2012 to 2025, and daily urban-rural air temperature records from 2015 to 2024. The analysis across eight taluks revealed a substantial conversion of agricultural and forest lands into built-up areas, alongside a progressive decline in major water bodies. The results show a persistent urban-rural temperature gradient, with elevated urban temperatures strongly associated with increased built-up density, reduced vegetation, and shrinking water bodies, especially during the pre-monsoon season.

Why it matters — It moves beyond typical satellite-derived land surface temperature snapshots by integrating long-term, ground-based air temperature observations with hydrological decline data, establishing a direct link between shrinking water bodies and localized thermal stress.

Discover Cities · pdf · doi

A comparative life cycle performance assessment of grocery product lines across all logistics elements in South Africa

This study conducted a comparative environmental life cycle assessment of beef, bread, and sugar supply chains in South Africa using SimaPro v.9.1 and the ReCiPe2016 midpoint methodology across 10 impact indicators. While beef has the highest environmental impact per individual item (41%), bread production dominates overall national emissions when scaled to annual consumption patterns, with bread transport and sugar packaging also driving high impacts of over 88% and 60% respectively.

Why it matters — It pinpoints the exact logistics stages where environmental interventions should be targeted for different food types, showing that beef and bread impacts are concentrated in raw production and processing, whereas sugar impacts are concentrated in packaging and storage.

Caveat: The analysis is limited to a cradle-to-gate scope, meaning it excludes the environmental impacts of retail, consumer transport, home storage, and food waste.

Case Studies on Transport Policy · doi

Assessing the greenhouse gas emissions related to food shopping mobility behaviors of households in a metropolitan area

The study analyzed greenhouse gas emissions from the food-shopping trips of 398 households in the Montpellier Metropolitan Area, France, across central, inner suburban, and outer suburban zones. Using multivariate linear regression, it measured how transport modes, trip frequencies, distances, and retail environments relate to emissions, finding that higher emissions are linked to car ownership, multi-adult households, retired heads of household, and living over 400 meters from a supermarket.

Why it matters — It identifies 'positive deviants'—households in suburban and inner suburban areas that maintain low food-shopping emissions despite their location, demonstrating that proximity to tram stops and supermarkets can mitigate the high-emission patterns typically expected in car-dependent suburbs.

Caveat: The findings rely on self-reported household data from a single metropolitan area, which may limit direct generalizability to regions with different transit and retail structures.

Journal of Transport & Health · doi

Indoor–outdoor heat stress, housing characteristics, and health outcomes in an informal settlement: a mixed‑methods study from Dar es Salaam, Tanzania

This study monitored indoor and outdoor microclimates alongside household surveys in an informal settlement in Dar es Salaam, Tanzania, during February and March. Outdoor daytime temperatures regularly exceeded 35°C, with 70% of monitored days reaching 'danger' levels on the Heat Index, while indoor Heat Index values frequently surpassed outdoor levels at night. Although over 75% of surveyed residents reported feeling hot and uncomfortable indoors, adjusted regression models did not find statistically significant relationships between specific housing characteristics—such as window size, roof color, ceilings, or vegetation—and indoor heat levels or self-reported health symptoms.

Why it matters — The study provides empirical, localized measurements of indoor-outdoor thermal dynamics in a sub-Saharan informal settlement, demonstrating that substandard housing fails to offer nighttime thermal relief and challenging the assumption that simple physical housing modifications easily translate to measurable indoor heat reduction in these dense settings.

Caveat: The study's adjusted statistical models were unable to identify consistent, statistically significant housing predictors for indoor heat exposure or health symptoms, and the survey responses were not spatially or temporally paired with the microclimate observations.

Sustainable Cities and Society · pdf · doi

Compounded exposure in sustainable transportation: Identifying the spatial overlap between on-road vehicle emission hotspots and active commuting clusters

This study developed a data-driven framework to map vehicle-specific emissions of NOx, PM2.5, and CO2e across 95 census tracts in Surrey, Canada, using image-based traffic data and Moran's I cluster analysis. The framework identified five 'double jeopardy' zones where high active commuting clusters directly overlap with elevated traffic-related air pollution hotspots. Within the 14 highest-emission tracts, passenger trucks were found to generate 60% of CO2e and 45% of NOx, while heavy-duty vehicles contributed 57% of exhaust PM2.5.

Why it matters — It provides a scalable method to pinpoint exact urban corridors where pedestrians and cyclists face the highest toxic exposure, allowing planners to target emission mitigation policies at the specific vehicle classes driving the local pollution.

Caveat: The analysis is limited to a single municipality and relies on census-tract level aggregations, which may mask finer, street-level variations in exposure.

Sustainable Cities and Society · doi

Pre-planned air routes or dynamic 4D trajectories? A comparative study of UTM ConOps

This study evaluates three UAS Traffic Management (UTM) strategies using a simulation-based assessment to compare structured corridors without intersections, corridors with controlled intersections, and fully dynamic trajectory-based operations. The comparison measures the trade-offs between safety, efficiency, and computational requirements across these different operational concepts.

Why it matters — It provides a systematic, comparative evaluation of drone traffic management strategies, demonstrating that structured corridors offer safety benefits with low computational demands, whereas dynamic 'free flight' models only improve efficiency under restricted conditions and at a high computational cost.

Caveat: The findings are based on simulation results where the absolute performance metrics will vary depending on the specific setup and operational conditions.

Transportation Research Part C Emerging Technologies · doi

Daily active-mobility green space exposure and subjective health: An age-comparative perspective

This study tracked 162 Swiss adults (64 younger and 98 older) over 15 days, analyzing 1,106 person-days of GPS and accelerometer data to measure active-mobility green space exposure (AMGSE) during walking and cycling. Using the Normalized Difference Vegetation Index (NDVI), the researchers found no correlation between static home-neighborhood greenness and active-travel greenness. Mixed-effects ordinal logistic regression models revealed that higher overall active-travel greenness between individuals was positively associated with daily subjective health (beta = 0.894), and that daily fluctuations in this exposure had a stronger positive association with subjective health in younger adults (beta = 0.079).

Why it matters — The study demonstrates that static neighborhood greenness measures do not accurately reflect the actual green space exposure people experience during active travel. It also establishes that the daily health benefits of traveling through green spaces vary significantly by age group, suggesting that urban greening strategies must account for active transit corridors rather than just residential buffers.

Caveat: The study relies on self-reported subjective health as the primary outcome measure, which may be prone to different reporting biases across age groups.

Urban forestry & urban greening · pdf · doi

Categorizing Congestion: A Framework for Congestion Analysis across Urban Area Counties

The study introduces the Congestion Propensity Index (CPI), a predictive metric calculated at the county level to evaluate expected congestion development across the United States. The index integrates traditional congestion drivers like population density, active transit modes, and spatial opportunity distribution with specific indicators of urbanization and suburbanization dynamics.

Why it matters — It provides a nationally comparable metric that captures variation within metropolitan areas rather than treating entire cities as homogeneous units, allowing planners to tailor transportation policies to specific suburban and urban contexts.

Journal of Transportation Engineering Part A Systems · doi

The price of not owning: housing discipline among highly educated renters in urban China

Through qualitative interviews with highly educated renters in Nanjing, this study examines how China's homeownership ideology persists despite falling property values. It details how renters internalize policy discourses of rigid demand, separating the physical function of housing from its financial performance, while facing social surveillance and emotional penalties within an unregulated rental market.

Why it matters — The study reveals the specific social and psychological mechanisms that maintain the cultural necessity of homeownership in China, demonstrating that the pressure to buy persists through social networks and market vulnerabilities even when housing is no longer a reliable financial investment.

Caveat: The findings are based on qualitative interviews with a specific demographic of highly educated renters in a single Chinese city, which may not represent the experiences of other socioeconomic groups or regions.

Housing Studies · doi

Patterns of unsheltered homelessness over time: mapping visible urban encampments in Salt Lake City, Utah

This study mapped and analyzed 11,225 visible homeless encampments in the urban core of Salt Lake City, Utah, using weekly in-person observations over an 18-month period. Using geospatial mapping, ANOVA, and negative binomial regression, the analysis found that encampments were largely absent from the downtown central business district but concentrated in open spaces, parks, and areas near light rail stations. Encampment visibility dropped sharply after August 2021, though specific northern zones of the city maintained highly persistent concentrations.

Why it matters — The research demonstrates that local political and enforcement decisions are stronger drivers of where unsheltered populations camp and persist than environmental factors, seasonality, or official land use classifications.

Caveat: The findings rely on visible encampments documented via in-person observations, which may underrepresent less visible or hidden unsheltered populations.

Urban Geography · doi

A Domain Knowledge–Enhanced Theme Expansion Method for Earth Surface System Science Dataset Recommendation

The researchers developed a domain knowledge-enhanced theme expansion method that constrains large language models to act as semantic selectors rather than free-text generators during dataset retrieval. The system uses a three-tier 'domain-theme-instance' knowledge base to map user queries to actual metadata keywords, and was evaluated using a self-constructed geoscience dataset (GeoFinder) and an open-source benchmark (DataFinder) across both sparse and dense retrieval architectures.

Why it matters — It prevents large language models from generating hallucinations and semantic noise when retrieving highly specialized Earth science datasets, significantly improving search recall and ranking quality without requiring manual query reformulation.

Transactions in GIS · doi

From Static to Dynamic: Evaluating the Impact of Temporal Bias in Historical Street View Images for Cross‐View Geolocalization

The study evaluates how temporal variations in Street View Images (SVIs) affect the performance of two deep learning cross-view geolocalization models, TransGeo and SAFA. Researchers constructed a temporally diverse dataset of historical SVIs spatially aligned with the CVUSA validation set, using semantic segmentation and SHAP analysis to measure how visual changes in urban infrastructure and natural landscapes impact retrieval accuracy.

Why it matters — It demonstrates that temporal shifts in imagery cause a substantial decline in retrieval accuracy for state-of-the-art geolocalization models, proving that geospatial AI models trained on static imagery are highly vulnerable to real-world temporal bias.

Caveat: The evaluation is limited to the geographic and structural footprint of the CVUSA dataset.

Transactions in GIS · doi

Geography and ‘The New’

This intervention presents reflections from five contributors on the complex role of 'the new' in human geography, originating from a plenary panel at the RGS-IBG 2025 annual conference. It examines how claims of novelty function within academic audit systems, digital publishing economies, and knowledge generation practices.

Why it matters — It initiates a critical disciplinary discussion on how geography values novelty, helping researchers navigate the ethical and political pressures to constantly produce new concepts versus sustaining existing ideas.

Transactions of the Institute of British Geographers · doi

Public transport and the paradox of socioeconomic segregation and diversity

Using mobile phone data from 8.3 million users in Beijing, China, this study reconstructs segment-by-segment transit trajectories to measure socioeconomic diversity at both destinations and along transit corridors. The analysis reveals that moderate improvements in spatial accessibility correlate with lower ridership diversity, and that buses experience a drop in diversity during peak hours while subways maintain high diversity throughout the day.

Why it matters — It demonstrates that expanding transit access does not automatically foster social mixing, revealing instead how network structure and transit mode create distinct spatial and temporal patterns of socioeconomic sorting.

Caveat: The findings are based on a single case study of Beijing and rely on mobile phone location data as a proxy for rider demographics and trajectories.

Urban Studies · pdf · doi

From official blueprint to youth perception: A Q methodology study of the youth-friendly city in Qingdao, China

Using Q methodology, this study maps how young residents in Qingdao, China, perceive the state's youth-friendly city policies. It identifies three distinct youth viewpoints that prioritize institutional fairness, everyday affordability, and secure opportunities over the state's growth- and spectacle-driven urban development.

Why it matters — It demonstrates a misalignment between state-led, human-capital-focused urban planning and the actual lived aspirations of young citizens, conceptualizing this gap as a form of spatial injustice termed discursive deprivation.

Caveat: The findings are based on a qualitative Q-methodology study in a single Chinese city, which may limit direct generalizability to other national or institutional contexts.

Urban Studies · doi