A Pathway-Based Methodology for Setting Quantitative Targets of Urban Heat Adaptation

City-Heat Equity Adaptation Tool (City-HEAT): Multi-objective optimization of environmental modifications and human heat exposure reductions for urban heat adaptation under uncertainty

Recently, human-centered urban heat assessment and adaptation planning have become increasingly relevant to local governments, leading to the development of numerous plans to address related issues. However, policies that integrate the latest scientific methods and tools are rarely implemented. To guide decision-making, budget planning and policy development, data-driven approaches are gaining more attention. These require local and scientific knowledge to collect relevant data sets, provide interpretation guidelines for city departments, and deliver tailored decision-relevant data at the right time.The Data2Resilience (D2R) project aims to develop an informative, data-driven dashboard that enables city officials and citizens to learn about thermal comfort, access current heat stress throughout the city and thereby adapt to urban heat conditions. This is achieved with a biometeorological measurement network consisting of 80 stations, which was designed and implemented with the city of Dortmund. The stations are under ownership of the city and part of the smart city ecosystem, which ensures long-term maintenance and data availability. This effort is complemented with a near real-time service that models thermal comfort based on SOLWEIG, using as input in-situ measurements and NWPs from ICON-D2. The output data are provided with a 3 m spatial resolution, to enable street-level decision-making. The results of both approaches are stored in databases and a backend was developed to make this data accessible via an API, which finally serves as the backend of a dashboard to visualize the meteorological conditions of the city for various stakeholders in Dortmund. The dashboard facilitates the exploration and interaction with station data and modeling results to gain a deeper understanding of the local differences of heat stress, while delivering objective numbers to argue and guide heat adaptation measures.

Cities are recognised as key players in global adaptation and mitigation efforts because the majority of people live in cities. However, in Europe, which is highly urbanized and one of the most advanced regions in terms of environmental policies, there is considerable diversity in the regional distribution, ambition and scope of climate change responses. This paper explores potential factors contributing to such diversity in 200 large and medium-sized cities across 11 European countries. We statistically investigate institutional, socio-economic, environmental and vulnerability characteristics of cities as potential drivers of or barriers to the development of urban climate change plans. Our results show that factors such as membership of climate networks, population size, GDP per capita and adaptive capacity act as drivers of mitigation and adaptation plans. By contrast, factors such as the unemployment rate, warmer summers, proximity to the coast and projected exposure to future climate impacts act as barriers. We see that, overall, it is predominantly large and prosperous cities that engage in climate planning, while vulnerable cities and those at risk of severe climate impacts in the future are less active. Our analysis suggests that climate change planning in European cities is not proactive, i.e. not significantly influenced by anticipated future impacts. Instead, we found that the current adaptive capacity of a city significantly relates to climate planning. Along with the need to further explore these relations, we see a need for more economic and institutional support for smaller and less resourceful cities and those at high risk from climate change impacts in the future.

Pressing challenges in urban adaptation planning to extreme events include: (1) involving vulnerable populations in the impacted area; and (2) employing a multi-level stakeholder collaborative process to build consensus for action. These processes become even more important as adaptive urban planning is recognized as an effective governance model for adaptation to climate change. In a case study of a low to moderate income community vulnerable to present and increased coastal storm surge flooding, the Supported Community Planning Process was employed because (a) most residents of East Boston affiliate primarily with their own local neighborhoods and (b) the residents need targeted expertise to help them understand some of the scientific and technical aspects of adaptation planning. Collaboration was necessary among three sets of critical stakeholders interested in adaptation strategies in East Boston — the local residents and small businesses, the City of Boston, and the agencies that provide infrastructure services — because some adaptation actions will collectively protect assets of all. The overall process occurred successfully because of positive, knowledgeable, and direct exchange of values and goals. The research illustrates how marginalized populations can be effectively engaged in urban adaptation planning, and how that process can be combined in multi-level stakeholder collaborative planning so that plans might be developed that meet multiple shared and individual goals in a cost-effective manner.

Indications point to exacerbated socio-economic inequalities and/or the emergence of new ones from climate-adaptive interventions in urban form, such as green and blue infrastructure (GBI), adaptive land uses, and urban design measures. We combine a systematic review and content analysis to review 136 peer-reviewed articles (published between 2008 and 2020) on urban climate justice in adaptation in order to: (1) review the emergence of the discourse on climate justice's pillars (i.e., distributive, procedural, and recognitional justice) vis-à-vis urban climate adaptation; (2) investigate the correlations between climate justice and the adaptive urban form interventions (GBI, adaptive land uses, and urban design measures); and (3) identify the spatial and scalar connections between the climate justice pillars and the adaptive urban form interventions. The findings reveal several trends, including: a deficit of empirical studies that deploy the climate justice pillars for assessing adaptive urban form interventions; an overemphasis on normative suggestions and/or critiques without clarifying “how” to advance climate justice; a dearth of urban design discussions on climate justice; a particular lack of connections between recognitional justice and urban form; and last, a dearth of studies that investigate the justice outcomes of adaptive urban form interventions across multiple spatial and temporal scales.

Progress, knowledge gap and future directions of urban heat mitigation and adaptation research through a bibliometric review of history and evolution

Communities are increasingly looking to land use planning strategies based on a less auto-dependent urban form to reduce the need for travel, especially drive-alone travel. In recent years, several studies have attempted to test the impact urban form has on travel behavior to determine if such designs are warranted. The results of these studies are mixed because of several shortcomings. Some shortcomings can be attributed to data availability; others are a product of the techniques used to characterize urban form or travel. Still other shortcomings are embedded in the strategies employed, using cross-sectional travel data and correlating travel outcomes with urban form. The line of research is being extended, aimed at isolating the influence of urban form on travel behavior; a new research strategy is presented using longitudinal travel data in concert with detailed measures of travel behavior and urban form. Data sources from the Puget Sound are described and a research strategy is presented that permits a pretest-posttest analysis of households’ travel behavior before and after they changed residential location. Early results show few changes in household travel behavior after a move, suggesting that attitudes toward travel are firmly entrenched and postmove travel provides little insight into how changes in urban form affect travel. Although a pretest-posttest makes valiant strides in shedding new light on the matter, the complex phenomenon being addressed requires myriad approaches. More comprehensive research techniques and even research approaches based on different different traditions are much needed to better understand how urban form and travel interact.

The importance of urban form as a key factor affecting future development and transformation patterns is well-recognised in urban morphology. However, despite the need for a diachronic approach to rigorously understand the form-change relationship, studies utilising longitudinal datasets remain scarce, and only a small fraction employs quantitative methodologies and morphometric approaches. This paper aims to quantitatively examine how the character of urban form elements and their spatial arrangements influence patterns of physical change, and to assess the performance of geometric and configurational urban form measures of plots, buildings, and streets in explaining physical change patterns over time. We hypothesise that configurational measures, being more sensitive to the relations between urban form elements, can better explain physical changes compared to conventional geometric measures predominantly adopted thus far. To test this hypothesis, we present a diachronic and quantitative methodology to measure urban form conditions and the patterns of physical change in Midtown Manhattan through four time frames (1890, 1920, 1956, and 2021), using a longitudinal geospatial database generated from historical cartographic resources and recent digital datasets. The association between urban form and physical change is demonstrated through statistical analysis. The findings prove that while the prevailing hypotheses emphasising the effect of geometric measures, such as size and shape, are often off the mark, configurational and access-based measures of plots and streets can accurately describe the dynamic relationships between form and change. The character of urban form patterns and structures measured by configurational variables is more reliable than the individual and geometric quality of urban form elements in explaining the dynamics of physical change and persistence. Our empirical findings add to the rapidly expanding fields of urban morphometrics and provide data-informed insights to improve the resilience and adaptive capacity of urban spaces.

CLIM-SEG: A generalizable segmentation model for heat and flood risk mapping

Six fundamental aspects for conceptualizing multidimensional urban form: A spatial mapping perspective

The growing frequency, intensity, and duration of extreme heat events necessitates interventions to reduce heat exposures. Local opportunities for heat adaptation may be optimally identified through collection of both quantitative exposure metrics and qualitative data on perceptions of heat. In this study, we used mixed methods to characterize heat exposure among urban residents in the area of Boston, Massachusetts, US, in summer 2020. Repeated interviews of N = 24 study participants ascertained heat vulnerability and adaptation strategies. Participants also used low-cost sensors to collect temperature, location, sleep, and physical activity data. We saw significant differences across temperature metrics: median personal temperature exposures were 3.9 °C higher than median ambient weather station temperatures. Existing air conditioning (AC) units did not adequately control indoor temperatures to desired thermostat levels: even with AC use, indoor maximum temperatures increased by 0.24 °C per °C of maximum outdoor temperature. Sleep duration was not associated with indoor or outdoor temperature. On warmer days, we observed a range of changes in time-at-home, expected given our small study size. Interview results further indicated opportunities for heat adaptation interventions including AC upgrades, hydration education campaigns, and amelioration of energy costs during high heat periods. Our mixed methods design informs heat adaptation interventions tailored to the challenges faced by residents in the study area. The strength of our community-academic partnership was a large part of the success of the mixed methods approach.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12889-022-14692-7.

Many cities around the world are undertaking climate change adaptation planning processes in contexts of considerable uncertainty due to climate risks. Understanding if and how these plans are aligned with future risks becomes crucial to assess whether they will effectively contribute to reduce vulnerability. Conversely, failing to account for uncertainty and risk can lead to underestimate climate shocks and hinder resilience. In this paper, we develop an analytical framework built on the four priorities for action of the Sendai Framework for Disaster Risk Reduction: (i) Understanding risk, (ii) Strengthening governance, (iii) DRR for resilience and (iv) Enhancing disaster preparedness, for each of which we defined a set of indicators to examine the degree of alignment of urban climate adaptation policies to future climate risks. We then test this approach in four cities that are considered early adapters or pioneers in climate change adaptation planning: Copenhagen (Denmark), Durban (South Africa), Quito (Ecuador) and Vancouver (Canada). Cities show the highest score in relation to governance, followed by disaster preparedness, while understanding risk and planning for resilience present the lower scores. We suggest that this result is at least partly explained by the lack of follow-up processes within the adaptation plans. In other words, it is uncommon to find monitoring systems that track the actual effectiveness of the adaptation policies and measures to reduce vulnerability or increase resilience. The first wave of urban adaptation plans should evolve beyond a battery of measures, to focus on a final goal: building long-term resilience.

It is crucial to the sustainable development of cities that we understand how urban form affects the concentration of fine particulate matter (PM2.5) from a spatial–temporal perspective. This study explored the influence of urban form on PM2.5 concentration in 286 prefecture-level Chinese cities and compared them from national and regional perspectives. The analysis, which explored the influence of urban form on PM2.5 concentration, was based on two types of urban form indicators (socioeconomic urban index and urban landscape index). The results revealed that cities with high PM2.5 concentrations tended to be clustered. From the national perspective, urban built-up area (UA) and road density (RD) have a significant correlation with PM2.5 concentration for all cities. There was a significant negative correlation between the number of patches (NP) and the average concentration of PM2.5 in small and medium-sized cities. Moreover, urban fragmentation had a stronger impact on PM2.5 concentrations in small cities. From a sub-regional perspective, there was no significant correlation between urban form and PM2.5 concentration in the eastern and central regions. On the other hand, the influence of population density on PM2.5 concentration in northeastern China and northwestern China showed a significant positive correlation. In large- and medium-sized cities, the number of patches (NP), the largest patch index (LPI), and the contagion index (CONTAG) were also positively correlated with PM2.5 concentration, while the LPI in small cities was significantly negatively correlated with PM2.5 concentration. This shows that, for more developed areas, planning agencies should encourage moderately decentralized and polycentric urban development. For underdeveloped cities and shrinking cities, the development of a single center should be encouraged.

Changes in transport behavior during the financial crisis. An analysis of urban form, location and transport behavior in the greater Copenhagen area 2006–2011

Urban areas face increasing challenges in adapting to the impacts of climate change, particularly concerning heat impacts. Densely populated areas are especially affected by the adverse consequences of extreme heat, which highlights the urgent need for local heat adaptation practices.This article evaluates the "CoolCo's—Cooling Corners and Corridors" project in Józsefváros, Budapest, as a case study in urban heat adaptation through co-design. Guided by the principles of the New European Bauhaus (NEB), the project aims to address urban heat impacts through integrating the three NEB pillars of sustainability, beauty and inclusivity in its implementation. Utilizing a participatory co-design process, the initiative integrates modular urban furniture, greenery, and information panels to provide a small-scale solution for adapting the public space to heat. The impact of the project is evaluated along the lines of the NEB using a multi-criteria assessment.The assessment identifies challenges in aligning innovative, small-scale solutions with existing municipal frameworks and stresses the need for ongoing community involvement and management strategies to ensure the long-term sustainability of the interventions. Ultimately, CoolCo's demonstrates the potential of locally-driven initiatives to catalyze transformative change in urban landscapes, while also revealing gaps in the NEB's focus on bottom-up adaptation strategies. This study contributes to the discourse on climate change resilience and urban transformation by advocating for a more inclusive and adaptable approach in future urban planning efforts.