Urban Heat Research Articles

Investigating the response of urban surface thermal environment to urban morphology changes in Nanjing

The urbanization process has significantly impacted urban morphology, which in turn has led to changes in the urban surface thermal environment (USTE). A summarization of the empirical patterns of past urban morphology changes and an evaluation of the USTE effects produced by different patterns will contribute to the advancement of scientific knowledge regarding the response of USTE to urban morphology changes and facilitate the development of sustainable urban planning and design practices. This study investigated the response of USTE to urban morphology from the overall and local based on the Local Climate Zone (LCZ) framework during 2005–2020 in Nanjing. The results validated the rationality of the LCZ framework for describing urban morphology changes and their USTE responses. It was found that the overall USTE was continuing to deteriorate, with an increase in high temperature and sub-high temperature areas. LCZ 4, LCZ 5, and LCZ 8 were the major contributors to overall urban heat, and their growth in the amount and changes in USTE characteristics mainly caused the overall USTE deterioration. In localized areas, it was found that urban regeneration had the most potential to optimize USTE. The conversion processes of LCZ 5 to LCZ 4, LCZ 8 to LCZ 4, and LCZ 8 to LCZ 5 were considered more advantageous in improving daytime USTE, which should be advocated. The results can provide important insights into the perception of urban morphology and USTE, and support the urban regeneration policies for climate-resilient cities from the environmental performance perspective.

Microscale urban heat variability and time-location patterns: Elevated exposure for bikers and rickshaw drivers beyond average city temperatures in megacity

Urban heat island effect creates diverse microclimates, influencing heat exposure and consequent health effects. Study measured heat exposure among delivery riders within their microclimate, comparing it with city's average temperature. We investigated how higher exposure affects work, health, and productivity of riders.For 21 days in winter and summer, we measured heat exposure during peak hours (under sun and shade) in riders' immediate environment, at seven high-traffic routes in Karachi, Pakistan. Recorded temperature were compared with city's ambient air temperature. In-depth interviews were conducted to assess the impacts on riders' health, welfare, and productivity.During winter, temperature was 5.0 °C higher under sun and 1.6 °C higher under shade, as compared to city average recorded temperatures. In summer temperature was 5.5 °C higher under sun and 1.8 °C higher in shade as compare to recorded city's average air temperature. Riders reported exhaustion, reduced productivity, income loss, and negative impacts on social wellbeing during hot days. For mitigation riders relied on strategies like staying hydrated and taking breaks from work under shades. Study demonstrated higher exposure to heat for riders in megacity as compare to city's recorded temperature. This led to reduced productivity and income losses, emphasizing need for urgent initiatives to safeguard riders' well-being.

Street trees: The contribution of latent heat flux to cooling dense urban areas

Trees are the most important natural factor to alleviate the urban heat island effect and the latent heat flux (LE) they release contributes significantly to urban cooling. In this study, the model ENVI-met was used to study the influence of building geometry on the LE exchanged by trees at the block scale in compact urban areas. The building density (BD), building height (BH) and sky view factor (SVF) were used to characterize building geometry. The sensitivity of LE to building geometry was estimated by multi-linear regression analysis. The following conclusions were drawn:(1) the LE of trees is sensitive to building geometry, higher during daytime than night-time in winter and the higher during night-time than daytime in summer; (2) LE changes as expected across the seasons, with LE larger in summer; (3) The shade affects the LE of a tree by influencing the solar irradiance; (4) In winter the average LE of a single tree is larger with 0.06 than 0.12 fractional vegetation cover (FVC). This study can provide useful leads towards further research to explore latent heat exchanges by trees at the street scale.

A Study on the Effectiveness of Climate Adaptation Materials for Urban Heat Islands using Digital Twin and Computational Fluid Dynamics

This study analyzed the impact of climate adaptation materials on the mitigation of urban heat islands (UHI) using digital twin visualization and computational fluid dynamics (CFD) technology. The effects of UHI due to increased impervious surfaces have become more pronounced, and climate-adaptation materials are gaining attention as potential solutions. In this study, the impact of climate adaptation materials on UHI mitigation was analyzed using the CFD program STAR-CCM+ based on the finite volume method (FVM). The selected research site was Byeoryang-dong, Gwacheon City, and four simulation scenarios were created based on the emissivity values of the asphalt and concrete materials. The results showed that application of climate adaptation materials decreased the surface and aboveground (1.5 m) temperatures by 6.3 and 0.8 °C, respectively. This study suggests that climate adaptation materials can significantly mitigate UHI.

A Review of Environmental Conditions between Planned and Unplanned Urbanization with Special Emphasis on Kalyani and Ranaghat Urban Areas

Urban settlements in India are generally classified as planned or unplanned as opposed to planned or unplanned urban areas due to land use and taking into account various factors including physical social and economic considerations and land use patterns. Rapid urban growth in India, mostly in an unplanned fashion, is currently a major problem. Urban growth occurs through replacement of vegetation, agricultural areas, wetlands, etc. This results in an unprecedented increase in heat, which dominates the microclimate of urban areas and creates an environmental crisis. Geospatial technology plays a unique role in planned and unplanned urban areas of West Bengal by monitoring spatio-temporal changes in urban heat by estimating land surface temperature and analyzing built-in indices of vegetation cover. It can be classified as NDVI and NDBI suggests that urban heat is controlled by surface character which is analyzed for proper planning for sustainability of urban areas

A Methodological Framework for High-Resolution Surface Urban Heat Island Mapping: Integration of UAS Remote Sensing, GIS, and the Local Climate Zoning Concept

The urban heat island effect (UHI) is among the major challenges of urban climate, which is continuously intensifying its impact on urban life and functioning. Against the backdrop of increasingly prolonged heatwaves observed in recent years, practical questions about adaptation measures in cities are growing—questions that traditional meteorological monitoring can hardly answer adequately. On the other hand, UHI has long been the focus of research interest, but due to the technological complexity of providing accurate spatially referenced data at high spatial resolution and the requirement to survey at strictly defined parts of the day, information provision is becoming a major challenge. This is one of the main reasons why UHI research results are less often used directly in urban spatial planning. However, advances in geospatial technologies, including unmanned aerial systems (UASs), are providing more and more reliable tools that can be applied to achieve better and higher-quality information resources that adequately characterize the UHI phenomenon. This paper presents a developed and tested methodology for the rapid and efficient assessment and mapping of the effects of surface urban heat island (SUHI). It is entirely based on the integrated use of data from unmanned aerial systems (UAS)-based remote sensing methods, including thermal photogrammetry and GIS-based analysis methods. The study follows the understanding that correct SUHI research depends on a proper understanding of the urban geosystem, its spatial and structural heterogeneity, and its functional systems, which in turn can only be achieved by supporting the research process with accurate and reliable information resources. In this regard, the possibilities offered by the proposed methodological scheme for efficient geospatial registration of SUHI variations at the microscale, including the calculation of intra-urban SUHI intensity, are discussed in detail. The methodology builds on classical approaches for using local climate zoning (LCZ), adding capabilities for precise delineation of individual zone types and for geostatistical characterization of the urban surface heat island (SUHI). Finally, the proposed scheme is based on state-of-the-art technological tools that provide flexible and automated capabilities to investigate the phenomenon at microscales, including by enabling flexible observation of its dynamics in terms of heat wave manifestation and evolution. Results are presented from a series of sequential tests conducted on the largest residential area in Bulgaria’s capital city, Sofia, in terms of area and population, over a relatively long period from 2021 to 2024.

Urban burden of disease estimation for policy making

Abstract Introduction The Urban Burden of Disease Estimation for Policy Making (UBDPolicy) project aims to estimate the health impacts resulting from urban and transport planning related exposures in nearly 1000 European cities. So far, quantitative burden of disease assessments have estimated premature mortality attributable to the environmental stressors of air pollution, noise, urban heat islands and lack of green space for the year 2015. Regular reporting and trend monitoring of the health impacts associated with urban environments is crucial for assessing the wider impacts of urban and transport planning. Methods For almost 1000 European cities, quantitative Health Impact Assessments (HIAs) will be conducted that employ the comparative risk assessment methodology. Baseline exposure levels of air pollution, noise, urban heat islands and green space will be estimated and preventable health impacts modelled using counterfactual exposure scenarios. Analysis will comprise two components: firstly, the 2018 HIA will incorporate multiple environmental exposures for that year, while the second component will monitor trends at three-yearly reporting intervals covering the years of 2015, 2018, 2021 and 2024. Results Results are intended to shape evidence-informed urban planning and policies throughout Europe. By ranking cities according to environmental exposures and health impacts, cities are encouraged to address challenges and learn from successful urban design and planning policies in other cities. Discussion HIAs serve as an effective tool for identifying the health impacts of current and future urban policies. The provision of burden of disease estimates will provide policy-makers and practitioners robust data for informed decision-making, while estimates over time will allow tracking of changes from implemented policies. To fully harness the potential of cities as key drivers of sustainable and healthy living, robust evidence must be at the forefront of this change. Key messages • A multitude of urban and transport planning pathways contribute toward the health of urban populations. • Compact city designs often promote health, however there are exceptions.

Integrative Remote Sensing Approaches Using Generative Adversarial Networks for Urban Heat Island Analysis and Mitigation

Integrative Remote Sensing Approaches Using Generative Adversarial Networks for Urban Heat Island Analysis and Mitigation

Climate change health challenges – a study on heat health-related adaption measures in Germany

Abstract Problem Increasing extreme heat events of summer 2003, 2010 and 2015 induced a rising impact on heat health morbidity and mortality in Germany. A considerable proportion of urban population is affected by thermal discomfort due to the urban heat island burden during summer, particularly vulnerable people at risk. Concerted action to develop appropriate heat health adaptation measures is needed. Description As part of the National Adaptation Strategy to Climate Change an expert working group published ‘Recommendations for Action for the Preparation of Heat Action Plans’ for Germany in 2017. A first country-wide project had been conducted between 2019 and 2023 which investigated the status and impact of current or planned Heat Health Action Plans (HHAP), and adaptation measures appropriate to protect and prevent human health. As part of this project an online survey was conducted in May/June 2020 on the awareness and degree of use of the 2017 recommendations and the development and implementation of HHAP. Results This survey had been carried out to assess the current state of affairs as well as factors of success and barriers in the development and implementation of HHAP, with a particular focus on municipal environment and health administrations. In total 116 questionnaires had been responded, mainly by participants from the environment sector (53%), and 32% from the public health sector. More than half of the respondents indicated to be aware of the recommendations (very well-known at the federal state level: 90%, at county level known by 43%), which were identified as very helpful by 81%. Respondents from large cities (> 100 000 inhabitants) were main contributors to the study (41 of 81 large cities replied; 34 rural counties responded). Key messages • The 2017 recommendations had been identified and used to start with HHAP. • Decision makers should develop structures for regulations that anchor HHAP as a nationwide instrument to be established timely.

Ultrawhite and ultrablack asymmetric coatings for radiative cooling and solar heating

Passive daytime radiative cooling, a zero-energy and zero‑carbon cooling technology, has significant potential to substantially reduce reliance on compression-based cooling systems, combat the urban heat island effect, and mitigate global warming. However, current radiative cooling materials either exhibit low efficiency or are susceptible to overcooling, resulting in cooling penalties on winter days. In this work, we designed and fabricated the ultrawhite and ultrablack asymmetric coatings. The top-layer, designed for efficient radiative cooling, consists of a porous polymethyl methacrylate and hollow silica microspheres composite. The underlayer, tailored for solar heating, is composed of a carbon nanotubes and carbon black composite. The cooling side with an exceptional solar reflectivity of 0.98 and a mid-infrared emissivity of 0.97 achieves a comparable daytime subambient cooling of 7.6 °C, with a theoretical net cooling power of 98.8 W/m2. Conversely, the heating side with a solar absorptivity of 0.96, a ultra-high visible light absorptivity of 0.985, and a mid-infrared emissivity of 0.97, results in a daytime above-ambient heating of 12.8 °C, corresponding to a theoretical net heating power of 745 W/m2. Promisingly, our ultrawhite and ultrablack asymmetric coatings hold the promise of addressing the long-standing challenge of all-season temperature regulation, offering significant potential for electricity savings and CO2 emission reduction.

Implementation of WRF‐Urban Asymmetric Convective Model (UACM) for Simulating Urban Fog Over Delhi, India

AbstractAccurate fog prediction in densely urbanized cities poses a challenge due to the complex influence of urban morphology on meteorological conditions in the urban roughness sublayer. This study implemented a coupled WRF‐Urban Asymmetric Convective Model (WRF‐UACM) for Delhi, India, integrating explicit urban physics with Sentinel‐updated USGS land‐use and urban morphological parameters derived from the UT‐GLOBUS dataset. When evaluated against the baseline Asymmetric Convective Model (WRF‐BACM) using Winter Fog Experiment (WiFEX) data, WRF‐UACM significantly improved urban meteorological variables such as diurnal variations in 10‐m wind speed, 2‐m air temperature (T2), and 2‐m relative humidity (RH2) during a fog event. UACM also demonstrates improved accuracy in simulating temperature and significantly reducing biases for wind speed and daytime RH2 under clear sky conditions. UACM reproduced the nighttime urban heat island effect within the city, showing realistic diurnal heating and cooling patterns that are important for accurate fog onset and duration. UACM effectively predicts the onset, evolution, and dissipation of fog, aligning well with observed data and satellite imagery. Compared to WRF‐BACM, WRF‐UACM reduces the cold bias soon after sunset, thus improving the fog onset error by ∼3 hr. This study highlights the UACM's potential to improve fog prediction and its application in operational settings. With further investigation into different fog types, the UACM can provide crucial insights for preventive measures and reducing disruptions in urban areas.

Spatial Assessment of Urban Heat Island (UHI) in Kütahya using Landsat-8 Satellite Data

The Urban Heat Island (UHI) effect refers to the phenomenon where urban areas experience significantly higher temperatures than their rural surroundings due to human activities and modifications, such as replacing natural land cover with impervious surfaces, reducing vegetation, and increasing heat-absorbing materials. Kütahya central district has a dense population and building layout, which contributes to the intense UHI. Geographic Information System (GIS) and its tools are widely used in assessing UHI in urban areas, providing insights for both researchers and local authorities. Landsat-8 images acquired on August 8, 2023 (Path: 179, Row: 33, Cloud Cover: 0%) were utilized to create the Urban Heat Island (UHI) map for the study area. Through spatial analysis using Landsat-8 data for Kütahya city center, six different classes were defined, with the UHI map created using land surface temperature values. The highest and lowest UHI values vary between 4.245°C and -3.457°C. It has been observed that the average UHI increases by 12% in areas lacking dense building structures, characterized by rock surfaces and limited green areas. Conversely, in areas with parks, forests, and sparse settlements, the UHI decreases by 10%. With this study, a comprehensive evaluation of UHI was conducted for Kütahya city center. While the results obtained are expected to be an important resource for researchers and local authorities, they are also anticipated to be beneficial in the fields of engineering geology, urban geology, and urban planning.

Scale-Dependent Effects of Urban Canopy Cover, Canopy Volume, and Impervious Surfaces on Near-Surface Air Temperature in a Mid-Sized City

Cities are significantly warmer than their surrounding rural environments. Known as the ‘urban heat island effect’, it can affect the health of urban residents and lead to increased energy use, public health impacts, and damage to infrastructure. Although this effect is extensively researched, less is known about how landscape characteristics within cities affect local temperature variation. This study examined how tree canopy cover, canopy volume, and impervious surface cover affect daytime near-surface air temperature, and how these effects vary between different scales of analysis (10, 30, 60, 90 m radii), ranging from approximate street corridor to city block size. Temperature data were obtained from a car-mounted sensor, with traverse data points recorded during morning, afternoon, and evening times, plotted throughout the city of Portland, OR. The variability in near-surface air temperature was over 10° F during each traverse period. The results indicate that near-surface air temperature increased linearly with impervious surface cover and decreased linearly with tree canopy cover, with canopy volume reducing the temperature by 1° F for every 500 cubic feet of canopy volume for evening temperatures. The magnitude of the effect of tree canopy increased with spatial scale, with 60 and 90 m scales having the greatest measurable effect. Canopy volume had a positive relationship on presumed nighttime and early-morning temperatures at 60 and 90 m scales, potentially due to the impacts of wind fluctuation and air roughness. Canopy cover still contributed the largest overall decrease in street-scale temperatures. Increasing tree canopy cover and volume effectively explained the lower daytime and evening temperatures, while reducing impervious surface cover remains critical for reducing morning and presumed nighttime urban heat. The results may inform strategies for urban foresters and planners in managing urban land cover and tree planting patterns to build increased resiliency towards moderating urban temperature under warming climate conditions.

Evaluation and optimization of park cooling benefits based on cumulative impact and landscape pattern

City parks can cool the surrounding environment and mitigate the urban heat island (UHI) effect, considerable improving the city’s adaptability to climate. In this study, 20 city parks in Nanjing, China, were considered, and four indexes for quantifying the cooling benefits from a cumulative impact perspective were proposed. These indexes are park cooling area (PCA), park cooling efficiency (PCE), park cooling intensity (PCI), and park cooling gradient (PCG). The results reveal the following: first, city parks have a positive impact on the surrounding thermal environment. The factors park area (PA), park perimeter (PP), landscape shape index (LSI), and normalized difference vegetation index (NDVI) determine cooling benefits. Second, PA and PP are significantly positively correlated with PCA but are significantly negatively correlated with PCE. LSI is negatively correlated with PCE, while NDVI is positively correlated with PCI and PCG. No significant correlation exists between the four cooling indexes and modified normalized difference water index(MNDWI). Finally, different parks exhibit variations in their ability to provide cooling benefits. Special or community parks are more appropriately situated in areas with constrained urban land resources. In designing comprehensive parks, the intricate boundary features and vegetation conditions need to be considered to optimize their cooling effects. Moreover, a larger number of residents are allowed to enjoy cooling services. The findings of this project will aid in the construction and optimization of city parks in future to combat the UHI effect.

Nonlinear changes in urban heat island intensity, urban breeze intensity, and urban air pollutant concentration with roof albedo

This study systematically examines how the urban heat island (UHI) and urban breeze circulation (UBC) respond to an increase in roof albedo (αr) and its influence on urban air pollutant dispersion. For this, idealized ensemble simulations are performed using the Weather Research and Forecasting (WRF) model. The increase in αr from 0.20 to 0.65 decreases the UHI intensity, UBC intensity, and urban planetary boundary layer (PBL) height in the daytime (from 1200 to 1700 LST) by 47%, 36%, and 6%, respectively. As both UBC intensity and urban PBL height decrease, the daytime urban near-surface passive tracer concentration increases by 115%. The daytime UHI intensity, UBC intensity, and urban tracer concentration nonlinearly change with αr: For 0.10 ≤ αr < 0.80, the rates of changes in the UHI intensity, UBC intensity, and urban tracer concentration with αr overall increase as αr increases. For αr ≥ 0.80, the daytime roof surface temperature is notably lower than the daytime urban near-surface air temperature, the UHI intensity, UBC intensity, and urban tracer concentration very slightly changing with αr. This study provides insights into the associations between changes in roof surface temperature and roof surface energy fluxes with αr and those in UHI intensity.

Effects of Mixture Proportions and Molding Method on the Performance of Pervious Recycled Aggregate Concrete

The use of pervious concrete pavement systems with recycled aggregates is a sustainable and innovative solution to major urbanization challenges such as repurposing construction waste, alleviating urban waterlogging, and reducing heat-island effects. This study aims to investigate the effects of mixture proportions and molding methods on the performance of pervious recycled aggregate concrete (PRAC). To this end, the coarse aggregate size (4.75~9.5 mm, 9.5~16 mm, and 16~19 mm), the molding method (layered insertion-tamping and vibration molding with vibration times of 5 s, 10 s, or 15 s, respectively), and the replacement rate of recycled coarse aggregate (RCA) (0%, 30%, 50%, and 100%, respectively) are considered. The results reveal that the addition of RCA to permeable concrete weakens its permeability. However, the compressive strength of PRAC reaches its maximum value when the RCA replacement rate is 50%. A larger aggregate particle size (16~19 mm) enhances the compressive strength of PRAC, yet decreases the permeability of PRAC. By using vibration molding to fabricate PRAC, an extension to the vibration duration increases the compressive strength, yet concurrently decreases the permeability. Based on the compressive strength and permeability coefficient of PRAC, the optimal mixture proportions and molding method are suggested.

Urban Heat Island Differentiation and Influencing Factors: A Local Climate Zone Perspective

With the acceleration of urbanization, the urban heat island (UHI) effect has become a major environmental challenge, severely affecting the quality of life of residents and the ecological environment. Quantitative analysis of the factors influencing urban heat island intensity (UHII) is crucial for precise urban planning. Although extensive research has investigated the causes of UHI effects and their spatial variability, most studies focus on macro-scale analyses, overlooking the spatial heterogeneity of thermal characteristics within local climate zones (LCZs) under rapid urbanization. To address this gap, this study took the central urban area of Chengdu, constructing a LCZ map using multisource remote sensing data. Moran’s Index was employed to analyze the spatial clustering effects of UHI across different LCZs. By constructing Ordinary Least Squares (OLS) and Geographically Weighted Regression (GWR) models, the study further explored the influencing factors within these climate zones. The results showed that: (1) Chengdu’s built and natural environments had comparable proportions, with the scattered building zone comprising the highest proportion at 22.12% in the built environment, and the low vegetation zone accounting for 21.8% in the natural environment. The UHII values in this study ranged from 10.2 °C to −1.58 °C, based on specific measurement conditions. Since UHII varied with meteorological conditions, time, seasons, and the selection of rural reference points, these values represented dynamic results during the study period and were not constant. (2) Chengdu’s urban spatial morphology and UHII exhibited significant spatial heterogeneity, with a global Moran’s I index of 0.734, indicating a high degree of spatial correlation. The highest local Moran’s I value was found in the proportion of impervious surfaces (0.776), while the lowest is in the floor area ratio (0.176). (3) The GWR model demonstrated greater explanatory power compared to the OLS model, with a fit of 0.827. The impact of spatial morphological factors on UHII varied significantly across different environments, with the most substantial difference observed in the sky view factor, which has a standard deviation of 13.639. The findings provide precise recommendations for ecological spatial planning, aiming to mitigate the UHI effect and enhance the quality of life for urban residents.

Assessment of indoor radon levels at multiple floors of an apartment building in the historic center of Rome (Italy): a comprehensive study.

The urbanized area of Rome is largely built over volcanic deposits, characterized by a significant radionuclides content and consequently a high radon emanation potential. An accurate monitoring of workplaces and residential dwellings constitutes a first step towards mitigating the indoor radon exposure. Since radon diffusion dynamics involves complex interactions among many environmental parameters on different time scales, a proper assessment of radon concentration variations can be better achieved by means of active monitoring approaches. We present here the results of 1year of continuous measurements conducted in six premises (five apartments and a basement) at different floors of the same building in the Esquilino district, in the historical center of Rome. Collecting annual series of radon concentration enables us to identify fluctuations over a seasonal scale, with radon generally decreasing in the warm season. The simultaneous tracking of different floors should cancel the influence of geogenic radon and of building characteristics like age, typology, and construction materials. While the basement shows the highest radon concentration, indicating a major contribution from the ground, we observe indoor radon levels comparable at all the upper floors, questioning the common belief that high-risk exposure be limited to the lowest storeys. The use of active devices makes it possible to discriminate between average indoor radon measured during the day and overnight, when residents are more likely to be at home. Our analysis provides the characterization of the dynamics of the gas emanation and transport inside the buildings and of its temporal fluctuations, in relation to the environmental and meteorological conditions. Since the experiment was performed in the Roman urban contest, we cannot ignore the specificity of the retrieved data, affected not only by endogenous factors like life habits relative to ventilation and conditioning of the apartments, but also by exogenous factors, among which the warmer microclimate compared to the surrounding suburban and rural areas, due to the effects of urbanization (urban heat island effect).

Assessing the impact of urban parks across Köppen climatic zones: a systematic review

This review article addresses the gap in the literature concerning the role of urban parks in providing cooling effects in hot and arid climatic zones. Using systematic review and content analysis of manuscripts from 1999 to 2023 in Scopus and Web of Science databases, elements and indicators of landscape architecture and their impacts on mitigating urban heat islands (UHI) have been explored. Our data mining revealed 190 manuscripts categorized into four Köppen climatic zones: tropical/mega thermal, arid, temperate/mesothermal, and continental/microthermal. Results indicate a scarcity of studies on hardscape elements’ impact, particularly in desert and semi-arid zones, and limited recognition of landscape architecture’s role in urban park cooling, especially in hot desert climates. Green areas emerged as the most cost-effective cooling strategy, with grass planted to minimize water elements and enhance tree cooling effects. However, the lack of softscape in hot, arid zones poses a significant challenge in mitigating UHI. These findings bridge the literature gap and suggest avenues for future research, including investigating native urban tree species and optimizing park area, shape, and orientation.

Efficient Rendering of Digital Twins Consisting of Both Static And Dynamic Data

Abstract. The high number of vertices and faces present in a digital twin of a large scene poses a challenge when executing large-scale simulations that require the data to be rendered multiple times with slight changes such as the light conditions in a day-night cycle during a long period of time (weeks and even months). Adding urban morphology such as tree planting introduces a new layer of complexity due to the requirement for evaluating different tree configurations and their effect on the local environment in the context of urban heat islands. Using advanced rendering techniques such as splitting a single buffer into sub-regions with inplace updates as well as buffer orphaning multiple methodologies are evaluated.