Heatwave exposure inequality:An urban-rural comparison of environmental justice

The rapid growth of heatwaves' severity have increasingly endangered citizens’ health in the last decade. Evidence points to the environmental injustice of heatwaves: inequal heatwave exposure among socioeconomic groups. Failing to use an adequate indicator of thermal comfort at a large scale, the previous studies have not adequately scrutinized the environmental justice of heatwaves and their variations across a large-scale territory. This study is novel in an unprecedented analysis of psychological equivalent temperature (PET), a comprehensive measure of thermal comfort, across socioeconomic groups and the urban-rural gradient of the Netherlands, as a proxy for factors affecting heatwave vulnerability. The results show that heatwave inequality (measured by the Gini coefficient) is higher in less urbanized areas. It shows that the population aged 25–44, immigrants, tenants, and females are the most heat-exposed groups across all levels of urbanization. However, the population aged 25–44 is more likely to be overexposed in urbanized areas, and immigrants are more likely to be overexposed in rural areas. The results open discussion on the necessity of location-specific policies protecting the most heat-exposed groups in different areas. It also paves the way for future studies using broader PET simulations and expanding their scope to include citizens' daily movements.</p

Gendered geography of energy consumption in the Netherlands

Household energy consumption (HEC) significantly impacts global greenhouse gas emissions and can trigger fuel and energy poverty among vulnerable households. Due to environmental policies and geopolitical turmoil limiting the energy supply, HEC needs to be curbed. This urges the identification of most energy-dependent consumers at different locations and the particular life circumstances that trigger such a high level of dependency. A gender perspective can provide insights into the life circumstances of households. Applying a geographically weighted regression model on HEC, including explanatory parameters on gender composition, age, ethnicity, income, home ownership, microclimate, urban morphology and land cover, the results show significant variations in HEC of gender groups in 87% of Dutch residential zones. Women with an immigration background (20%), children younger than 14 years old -presumably single mothers (14%), old buildings in hot climates (10%), or high income (9%) are the most energy-dependent gender groups in a significant portion of residential zones. So are the men in large-size households (18%) and older-than-65-years men in rural areas (8%). The study offers discussions on the results and a series of policy recommendations.</p

Does 15-Minute Green space accessibility affect mental health in UK cities?

In recent years, multiple studies have analysed accessibility through the lens of the ‘15-minute city’ framework. This study aims to contribute to such studies by testing the associations between the 15-minute accessibility to green spaces and the self-reported wellbeing in England using spatial “big data” and GeoAI. To do so, we utilise the street networks from OpenStreetMap (OSM), NASA MODIS satellite images on land cover (MOD44B), governmental demographics from Office for National Statistics (ONS), and the mental health and wellbeing data from the Department of Health and Social Care. We study green space accessibility within the 15-minute (a well-known threshold in urban studies) by walking or driving from the centroid of each local authorities (LAs) and clinic commissioning groups (CCGs). Using machine learning models (ML), we investigate the relationhsips between access to different types of green surfaces and self-reported, wellbeing indicators, including “anxiety”, “feeling life is worthwhile”, “happiness”, and “life satisfaction”, while accounting for demographic factors such as age, gender, and income. To achieve this, first we retrieve the satellite images of green surfaces and construct spatial weight matrices (SWM) to calculate 15-minute accessibility for each study area, this can be a local district or a clinic commissioning group. The SWMs conceptualise accessibility based on “zone of indifference”. In this respect, they have a flat (100%) utility for areas within the fixed distance band of 15-minute walking (0-800m) and cascading linear utilities -equal to reverse metric distances- for the rest of the area within 15-minutes driving distance with 30km speed (800-7,500m). Using SWM and satellite images, we calculate three types of 15-minute green accessibilities for each study area: (1) access to tree-covered green surfaces, (2) access to non-tree-covered green surfaces, (3) access to both green surfaces combined. Second, we retrieve the four self-reported, well-being statistics for each study area and collect five types of control variables on: (a) gender composition of population; (b) presence of different age groups; (c) disposable income; (d) immigration status; (e) percentage of residents with physical disabilities or illness. Third, we conduct and compare the performances of three ML models, Decision Tree, Xgboost, Random Forest- in terms of RMSE (Root Mean Squared Error). We select the best performing model to illustrate the association between the green space accessibility and the self-reported wellbeing using SHAP's (SHapley Additive exPlanations) partial dependence plots, visualising the expected values of the green space accessibility against every possible wellbeing value

Urban form and surface temperature inequality in 683 European cities

Despite rapid urbanization and growing heat stress, comprehensive insights into the association between urban form and environmental inequality are lacking. We study the population-weighted Gini coefficient, the measurement of inequality, of the average land surface temperature (LST) in summer in 683 European cities (i.e. Functional Urban Areas) against thirty-four urban form indicators, i.e. population, area, compact ratio, local climate zones (LCZ), presence of grass, impervious surfaces, trees, water and albedo, elevation, aspect, Köppen-Geiger climate classification (KG) and latitude. We calculate density, Moran's I and Entropy measures to quantify cities' spatial structures and diversity. The area of each city is divided into 1 × 1 km spatial units, and inequality among such units is calculated. Using geographically weighted regression (GWR), we found that the impact of factors varies across the cities and that almost 70 % of overall inequality can be explained by urban form. The variables occasionally decreasing LST inequality were population density and concentration, LCZ 9, dry climate, and high latitude. The ones increasing it were urban size, LCZ 3, 5, 6, 8, entropy LCZ, impervious surfaces' density and concentration, trees, high elevation, aspect southwest, and polar climate. Ultimately, the study discusses the findings and proposes spatial strategies for mitigating inequality

Escalating environmental inequalities in smaller European regions: a data mining

Environmental inequality has been the focus of European scientists and policymakers in the past decades. This database is prepared to provide researchers with a multiscale, multivariate database on environmental inequality across different scales, i.e. the so-called NUTS region levels. To do so, the database offers the population-weighted average and Gini coefficient at four European NUTS region levels (NUTS 0, NUTS 1, NUTS 2, NUTS 3) over exposure to air pollution (NO2, O3, PM10, PM2.5), summer land surface temperature (LST), and Tree and Non-tree vegetated surfaces. The dataset can be used to compare and map the magnitude of inequalities related to each of the environmental hazards/services. Furthermore, it is helpful to identify the levels of scales with the highest and lowest levels of environmental inequality. To this end, this manuscript provides histograms and maps to present the potential for the use of the database

The two and half minute walk: fast charging of electric vehicles and the economic value of walkability

The number of electric vehicles in the Netherlands has sharply increased over the past decade. This has caused a need for the allocation of a substantial amount of new electric vehicle chargers around the country, which in turn has been acknowledged by a variety of legislative bodies. However, the approach of how these new charging infrastructures need to be spatially distributed has yet to be decided, including the distance that an electric vehicle charger could be allocated from the final destination of its driver. The hypothesis of this study is that if residents walk a longer distance to/from these charging stations, the chargers could be shared by a greater number of electric vehicle owners, and the total cost of the new charging infrastructure could be reduced. By using linear integer programming, the minimum cost of allocating new fast-charging stations in a central, densely populated area of Amsterdam, accounting for 7% of the city’s population, is calculated. The results show that if residents were to walk for five minutes (roughly 400 metres) instead of two and half minutes (roughly 200 metres), the overall cost of new electric vehicle chargers could be reduced by more than 1 million euros. The study also found that both the cost of new charging stations and their efficiency of use are vastly affected by the portion of the charging infrastructure that is saved for people visiting the area. The findings of this study are discussed in detail, including the proposal of potential further studies

Electricity grid and societal vulnerability interconnection: stakeholder implications and integrated solutions in Europe

The electricity grid is a pivotal element in the energy transition, serving as the backbone for integrating and distributing renewable energy. However, amid rapid digitalisation and decentralisation of energy systems, its limitations have become increasingly apparent, posing significant challenges for inclusive and equitable stakeholder engagement in the transition. Stakeholders including consumers, prosumers, energy communities, aggregators and electricity utilities, face unequal distribution of grid-related costs and benefits. There is thus a need to understand and address coupled grid-societal vulnerability (GSV). However, there is still no comprehensive study identifying factors influencing GSV and the corresponding challenges vis-à-vis stakeholders. Previous studies have predominantly focused on the disparities in access to hosting capacities for new renewable energy projects and grid congestion due to increased energy demand from households and businesses. We contribute to the literature by developing a comprehensive view of GSV through a systematic literature review of 185 peer-reviewed academic papers focusing on the European context. Three main factors influencing GSV are identified: grid constraints, cybersecurity risks, and regulatory barriers. A complex interrelationship exists between stakeholders in the electricity grid and, as a result, we find there are (in)direct implications of their grid challenges across stakeholders. Therefore, tackling GSV and inequalities in the energy transition requires an integrated solutions approach combining supportive policies, regulatory frameworks and market-based mechanisms with technological integration, innovations and consumer engagement

How small green spaces cool urban neighbourhoods: optimising distribution, size and shape

How can green spaces smaller than 1 ha improve outdoor thermal conditions in urban neighbourhoods? Considering the variability of cooling effects based on the relevant urban design parameters of size, shape, and spatial distribution, this study entailed development of different design scenarios combining these parameters for four neighbourhood typologies and simulates the thermal sensation of these scenarios using ENVI-met. Three aspects of cooling effects — the inside and outside cooling as well as the Park Cool Island (PCI) effects of the green spaces are separately analysed. The study shows that inside the small green spaces, the mean Physiological Equivalent Temperature (PET) of different cases can vary up to 4 ℃. Larger green spaces with a squared shape lead to cooler PET inside. For a good cooling outside the green spaces, a configuration of grouped small green areas can reduce the PET by 1.3 ℃, with distribution of the green spaces being the most influential factor. The PCI effect is mainly determined by size and shape of the green spaces, where a bigger size and squared shape leads to better cooling effects. But for neighbourhoods with radial streets, it is more related to the spatial distribution, which can result in a reduction of 10.2 ℃ in PCI for linear green spaces next to narrow streets. Guidelines for effective design scenarios are generated from this research, providing urban designers and planners with practical reference in neighbourhood greening projects for cooler cities

Distributed operation of Hydrogen integrated microgrids and transportation system considering energy sharing and ancillary service market

The widespread adoption of electric vehicles (EVs) and hydrogen fuel cell electric vehicles (HVs) is tightening the interdependence between power and transportation systems, calling for better coordination between them. To address this challenge, this paper proposed a distributed coordination method for the hydrogen-integrated microgrids and transportation system. First, we introduce energy sharing among microgrids which reduces the overall system cost by 16.2% and analyze how it improves the traffic flow. Additionally, we develop bidding models for microgrids participating in joint energy and ancillary service markets, maximizing flexible resources utilization and increasing revenue by 147%. A mixed vehicle flow transportation system model is then established, including EVs, HVs, and gasoline vehicles. To coordinate the two individual systems efficiently, a distributed algorithm is proposed, incorporating a filtering mechanism that reduces the communication burden by 63% during the iterative process. Uncertainties and nonlinearities are handled using distributionally robust method and linearization techniques. Finally, case studies validate the effectiveness of the proposed method and highlight the mutual impact between the two systems

Heat-prone neighbourhood typologies of European cities with temperate climate

Outdoor microclimates vary among different urban neighbourhoods depending on their morphological variations. The Local Climate Zone (LCZ) framework is a well-developed typomorphological classification used to capture the variation that characterises neighbourhood microclimates. However, it does not include detailed morphological parameters within neighbourhoods that have synergistic effects on microclimates. It is thus essential to develop neighbourhood typologies with detailed spatial descriptions. This study first identifies the LCZ in Amsterdam, London and Paris with the highest Land Surface Temperature (hereinafter referred to as the most heat-prone areas). Subsequently, parameters which are not covered by the LCZs were analysed, including building block's floor area ratio and shape factor, street canyon's orientation and Height-to-Width ratio, street total length, green space area, and tree cover ratio. The results show that LCZ 2-compact mid-rise areas are the most heat-prone. Employing K-means cluster analysis, four neighbourhood typologies are distinguished within the LCZ 2: mainly wide streets with N-S and E-W orientations, mainly narrow streets with N-S and E-W orientations, mainly narrow streets with NE-SW and NW-SE orientations, mainly wide streets with four orientations divided by 45°. These generalised neighbourhood typologies can be used as the basis for design interventions aiming at climate adaptation in heat-prone urban areas