High Sky View Factor Research Articles

The Impacts of Urban Morphology on Urban Heat Islands in Housing Areas: The Case of Erzurum, Turkey

The growing importance of climate change underlines the need to comprehend Urban Heat Islands (UHI), particularly those influenced by urban morphology. As progress has been made in understanding the macroscale relationship between urban morphology and UHIs, the microscale effects are often overlooked. This study, conducted in the city of Erzurum in Turkey, delves into the complex relationship between urban morphology and UHI intensity in different housing areas with distinct microclimates, focusing particularly on street networks, building systems, and land use. Pearson correlation analysis was performed to investigate the relationships between morphological indicators and UHIs in different housing areas. Key findings include that (1) noticeable UHI effects were observed, especially in dense areas with high-rise buildings. (2) UHIs reveal a strong correlation with both 2D and 3D urban morphological indicators. A moderate-to-high Sky View Factor (SVF) tends to reduce UHIs, while an extremely high SVF aggravates UHIs. (3) Enhancing street network integration emerges as a more effective strategy for mitigating UHI effects in mid-rise buildings compared to other morphological factors. The Normalised Difference Built-Up Index (NDBI) and Normalised Difference Vegetation Index (NDVI) may not reliably indicate UHIs in housing areas with a predominantly rural character. Consequently, this article recommends that urban morphology optimisation for UHI mitigation should prioritise spatial and indicator specificity in urban design and spatial planning for cities. Future research endeavours should investigate the influence of morphological indicators on UHI dynamics in different seasons, including various remote sensing indicators related to morphological structure, to enrich our understanding of daily UHI fluctuations within urban morphology research.

Visualization of urban roadway surface temperature by applying deep learning to infrared images from mobile measurements

Urban heat islands (UHIs) have been worsening, and Tokyo, Japan, is among the worst globally. The urban thermal environment requires measurement to formulate effective countermeasures. This study proposes a method for detecting roadways from infrared images of captured by a moving automobile and using deep learning to extract roadway surface temperatures from the detected roadways. Additionally, a roadway surface temperature map of Tokyo was created from 17,000 infrared images covering a route of 37 km and was then used to identify hotter and cooler areas of the city in order to validate the proposed methodology. The surface temperatures were high on wide roadways with a high sky view factor, but were lower and less variable in street canyons. Roadways perpendicular to the solar azimuth had lower temperatures due to shading by buildings. The accuracy of deep learning to detect roadway was imperfect, but a significant improvement in analytical efficiency was achieved. The method could also be applied to three-dimensional evaluation of urban surface temperatures by extracting surface temperatures for various city components, such as buildings and vegetation.

Modeling the effects of urban form on ventilation patterns and traffic-related PM2.5 pollution in a central business area of Bangkok

Traffic-related PM exposure is a significant concern in several cities. This study used ENVI-met simulation to perform the airflow and PM2.5 dispersions in Bangkok's central business district during summer. The impact of urban forms and traffic pollution on airflow and PM2.5 distributions was assessed using correlation analysis. Results showed that during summer, road traffic contributed to urban PM2.5 concentrations. Sky view factor and road area significantly affected wind speeds and PM2.5 concentrations, and these two parameters positively correlated. High wind speeds and PM2.5 concentrations were found in the urban main road, while those levels in the areas far from the road dropped by 50% due to building obstacles. Large open spaces (high sky view factor) could improve wind speeds in inner-city areas by 63%. Based on wind and PM2.5 performance classification, this study introduced new performance-based zoning, including five subzones with design recommendations. Urban planners and architects can use this information to improve pedestrian wind comfort and control air pollution dispersion from road traffic.

How Urban Morphology Relates to the Urban Heat Island Effect: A Multi-Indicator Study

Urban morphology quantitatively expresses a city’s spatial structure, internal relationships, and physical form. It has advantages for predicting urban growth and analyzing the current state of cities in the literature. A comprehensive study on the complex relationships between urban morphology and urban heat island intensity (UHII) is of great importance for mitigating the urban heat island (UHI) effect for megacities. This study models urban morphological indicators in fine resolution based on three aspects: building morphology, ecological infrastructure, and human activities. The model accurately captures UHII by employing the definition of UHI effects. The relationship between urban morphology and UHII was further examined using extreme gradient boosting (XGBoost) and Shapley additive explanations (SHAP). By taking central Beijing, China as study area, major findings include the following: (1) Significant daytime UHI effects were observed within the research area, particularly during the summer months, when it appears to be most severe. More than 90% of the region experiences varying degrees of the UHI effects. (2) UHI is significantly correlated with both 2D and 3D urban morphological indicators. Low sky view factor (SVF) and high SVF tend to mitigate UHI, whereas moderate SVF tends to aggravate UHI. (3) In densely populated areas, tall trees may be more effective than other forms of vegetation at mitigating UHI. Based on the aforementioned findings, this article suggests that urban morphology optimization should focus on seasonality, spatial specificity, and indicator specificity for megacities in urban design and spatial planning aimed at mitigating UHI.

Evaluating the Annual Effect of the Sky View Factor on the Indoor Thermal Environment of Residential Buildings by Envi-met

The effect of the sky view factor (SVF) on outdoor thermal comfort has been extensively explored, while its impact on the indoor thermal environment is ignored. This research combined Envi-met and kriging models to explore the annual effect of the sky view factor on the indoor thermal environment. Different from previous studies, this study explored the effect of the sky view factor on indoor temperature rather than outdoor temperature, and from the perspective of a full year instead of a typical summer day. The analytical results reveal that an increase in the sky view factor raised the indoor air temperature every month. Although a low sky view factor was beneficial to the insulation of the built environment at night, it was proven that in Chenzhou city, the indoor air temperature was still higher in a built area with a high sky view factor than with a low sky view factor. In addition, the sky view factor was shown to have a nonlinear relationship with indoor thermal comfort throughout the year. When the sky view factor increased from 0.05 to 0.45, the indoor temperature increased by around 10 °C at 16:00 and increased by about 4 °C throughout the night for each month, and from the view of the annual cycle, the cooling demand duration increased by 1611.6 h (18.4%), and the heating demand duration decreased by 1192.3 h (13.61%).

The effect of extremely low sky view factor on land surface temperatures in urban residential areas

Cities are becoming hotter due to global climate change and urban heat island intensification. This has resulted in an increased number of hospitalizations and deaths during heatwaves. Previous studies have reported a positive correlation between moderate to high sky view factor (SVF) values and land surface temperature (LST), but extremely low SVF situations that occur in urbanized residential areas have not been fully studied. This study investigated the relationship between SVF and summertime LST for urbanized residential areas ranging from very open to very closed considering external factors. Similar to previous studies, the results showed that low-rise detached housing was associated with a higher SVF and a higher LST than high-rise multifamily housing because the ground surface received more direct solar radiation. However, when the SVF was extremely low (less than 0.2) because of being surrounded by high-rise high-density flat-type apartments, this relationship was reversed due to the higher anthropogenic heat, lower ventilation performance, lower green infrastructure, and decreased longwave radiation even though daytime. This has major implications for the health and well-being of residents in high-density urban residential areas as they will receive a higher terrestrial radiation load than previously thought, a dangerous situation in the event of heatwaves. (200 Words)

Evidence of alliesthesia during a neighborhood thermal walk in a hot and dry city

Designing cities for thermal comfort is an important priority in a warming and urbanizing world. As temperatures in cities continue to break extreme heat records, it is necessary to develop and test new approaches capable of tracking human thermal sensations influenced by microclimate conditions, complex urban geometries, and individual characteristics in dynamic settings. Thermal walks are a promising novel research method to address this gap. During a thermal walk in Phoenix, Arizona, USA, we examined relationships between the built environment, microclimate, and subjective thermal judgments across a downtown city neighborhood slated for redevelopment. Subjects equipped with GPS devices participated in a 1-hour walk on a hot sunny day and recorded their experience in a field guide. Microclimate measurements were simultaneously collected using the mobile human-biometeorological instrument platform MaRTy. Results revealed significant differences in physiologically equivalent temperature (PET) and modified physiologically equivalent temperature (mPET) and between street segments with more than 18 °C (25 °C mPET) between the maximum and minimum values. Wider range of mPET values reflected the inclusion of individual level data into the model. Streets with higher sky view factor (SVF) and east-west orientation showed a higher PET and mPET overall. Furthermore, we showed evidence of thermal alliesthesia, the pleasure resulting from slight changes in microclimate conditions. Participants' sense of pleasure was related to the mean PET of the segment they just walked, with linear regression explaining over 60% of the variability. We also showed that estimated percent shade was significantly correlated with SVF, PET, mPET, and pleasure, indicating that participants could sense minor changes in microclimate and perceived shade as pleasant. Although generalization of results is limited by a low sample size, findings of this study improve the understanding of dynamic thermal comfort in complex urban environments and highlight the value of thermal walks as a robust research method.

The Influence of Diverse Building Height and Building Coverage Ratio on Outdoor Thermal Performance in Hot Climates: A Review

Although urban form can significantly affect outdoor climatic conditions, urban planners do not sufficiently consider such impact while designing new urban communities in Egypt. Proper configuration of urban blocks can make positive contribution to alleviating the adverse effects of urban climate. However, new cities are constructed to be formed from lowly dense buildings that overlook curvilinear streets networks without considering orientation. Furthermore, the use of unified building heights, spaces of low aspect ratio and high sky view factor lead to less shaded areas. The research at hand aims to shed light on literature that discuss urban form parameters and their relation with outdoor spaces thermal performance in warmer climates. These studies are classified, analysed and compared in terms of the investigated parameters, and the methodological approach of each study. The findings can help defining gaps in the existing literature while providing holistic overview of the current state of art.

Effects of Different Urban-Vegetation Morphology on the Canopy-level Thermal Comfort and the Cooling Benefits of Shade Trees: Case-study in Philadelphia

Urban morphology directly influences heating or cooling rate in street canopies. This paper assessed cooling benefits of street-trees in Philadelphia city, PA considering morphological elements. We assessed summertime thermal comfort for humid subtropical climate (i.e. Philadelphia) by studying human-biometeorological parameters such as Mean-radiant temperature (Tmrt) and Physically Equivalent Temperature (PET) utilizing Rayman model. This paper will; 1. Quantify impacts of built environment with and without existing vegetation on pedestrian level temperature, 2. Observe impacts of Tmrt, surface temperature (Ts), PET and global radiation at road intersections in five different scenarios where urban canopies are characterized as: a) built environment without vegetation (BE), b) built environment with existing vegetation (BEEV), c) built environment with additional vegetation after 1-year (BEAV-1), d) built environment after 5-years (BEAV-5) and e) built environment after 10-years growth period (BEAV-10). Compared results with the BE scenario suggest that, planting trees in residential and mixed-use sites with higher Sky-view factor (SVF) can improve pedestrian comfort in the long-term by reducing Tmrt, and PET, compared to the commercial sites with lower SVF and Ts. Mixed-use sites were observed to provide highest thermal comfort and further benefit from tree plantation, while commercial sites receive lowest cooling benefit from street trees.

Association of urban built environment and socioeconomic factors with suicide mortality in high-density cities: A case study of Hong Kong

Population ageing, climate change and urbanization have been occurring rapidly globally. Evidence-based healthy city development is required to improve living quality and mitigate the adverse impact of city living on both physical and mental health. We took a high-density city as an example to explore the association of built environment and suicide mortality and preferably to offer some implications for better future city development. Poisson generalized linear models with generalized estimation equations were employed to regress suicide mortality rate on four urban built environment variables (frontal area density (FAD), sky view factor (SVF), ground coverage ratio (GCR), and street coverage ratio (SCR)), as well as socioeconomic factors, population density, and greenery. The association for different causes of death and within different subgroups was also investigated. Generally, higher FAD and GCR were associated with higher suicide mortality while higher SVF and SCR were associated with lower suicide mortality. Age was a significant effect modifier. An interquartile range increase in FAD, SVF, and GCR was associated with 0.81 (95% confidence interval (CI) 0.71–0.92), 1.41 (95% CI 1.04–1.91), and 0.70 (95% CI 0.50–0.98) times the risk of suicide among the people aged over 70, respectively. Higher population density and unmarried status were generally associated with higher suicide rate whereas higher education level was associated with a decreased risk. Unfavorable built environment could increase risks for successful suicide attempts. Better urban development with morphological control mitigating intensifying urban heat island and other micro-environment changes are warranted to promote not only physical but psychological health.

Mediterranean Morphologies in Hot Summer Conditions: Learning from France’s “Glorious Thirty” Holiday Housing

Climate change and rising temperatures lead to an air-conditioning proliferation in summertime of the Mediterranean regions. This study links urban morphology to the microclimate. It claims that a lesson can be drawn from holiday housing morphologies designed with an additive approach during the “Glorious Thirty” French coastal development (1946-75). It is based on a morphological analysis of four case studies, with on the one hand re-drawing and site visiting, on the other hand, assessment of environmental performance through key parameters: Absolute Rugosity, Compactness Ratio, Building Density, Mineralization, Sky View Factor (SVF) and Height/Width (H/W) Ratio. Compared to literature reference values of a traditional courtyard morphology, the case studies are less compact and with a lower H/W Ratio (higher SVF), but they are less mineral than a historic medieval city centre. This research contributes to the search for semi-collective alternatives (for example additive morphologies) to individual housing in peri-urban areas, with high environmental performance in the summertime.

The impact of outdoor shading strategies on student thermal comfort in open spaces between education building

The aim of this study is to evaluate and improve student thermal sensation in the open spaces of the Faculty of Engineering, Assiut University, Egypt using different shading strategies. Firstly, the thermal conditions of outdoor spaces were evaluated based on field measurements in different locations of shaded outdoor spaces between educational buildings within the Faculty of Engineering. Then, the microclimate model ENVI-met was applied to evaluate the impact of different shading scenarios on improving student thermal comfort. Also, the Thermal Sensation Vote (TSV) of the was studied by a questionnaire survey using the 118 effective questionnaire responses of the student sitting in the spaces between buildings. Hence, the results concluded that high air temperature is found in most outdoor open spaces, especially in the sitting area with low trees density and high Sky View Factor (SVF). Similar results were obtained by the TSV analysis. In addition, a significant reduction in the Predicted Mean Vote (PMV) values resulted from the ENVI-met simulation model with an average temperature difference of 0.7 °C due to increasing tree density for the main open space. Thus, it is recommended to increase greenery and tree density, to reduce heat stress and create student thermal comfort in outdoor.

Outdoor thermal environment of an open space under sea breeze: A mobile experience in a coastal city of Sydney, Australia

Wind is potential to regulate urban temperature, while the wind-induced cooling effect has not been well understood in association with built form. Therefore, this paper investigated the cooling effects of sea breeze on outdoor thermal environment with the consideration of built form in an open space of Sydney, Australia based on mobile measurement. Results indicate the open space underwent lagging sea breeze influence. The wind speed and air temperature exhibited spatiotemporal variations. During the measurement period, the air temperature gradually decreased while the wind speed increased. The daily average wind speed was spatially proportional to sky view factor (SVF), while wind could be amplified by channel effect and building disturbance. The most “open” point with high SVF underwent the highest daily average air temperature. The grassland did not show the cooling potential while underwent the highest temperature. In comparison, the location under both tree and building shades underwent the lowest temperature. Both solar radiation and wind speed had significant influences on the air temperature, while the influence of wind speed was less significant. The wind in more “open” area had more significant cooling potentials, while the cooling potential of wind within shading or wind amplification zone was less significant. Moreover, the wind cooling potential was more obvious when the background temperature was higher. The cooling potential of wind above grassland might be inhibited by water scarcity and heat accumulation. Overall, this study indicates that wind is also a critical factor affecting local temperature and it should be considered in local temperature studies, as well as the urban planning and design for overheating mitigation.

Reduced effectiveness of tree planting on micro-climate cooling due to ozone pollution—A modeling study

Urban tree planting is an important measure to provide micro-climate cooling (MCC) in megacities. However all of the studies available in the literature were focused on an ideal and clean environment where trees are not under environmental stresses. Here, we studied the effects of ambient ozone on the leaf area index (LAI) of trees and the resultant reduction in the effectiveness of trees in providing MCC. The ENVI-met model, which was well validated against our bio-meteorological measurements, was used to quantify the effect of reduced LAI on the cooling performance of trees in two urban sites of Hong Kong. Under the influence of ambient ozone stress with a high sky view factor (SVF), the sensible heat fluxes and surface temperatures were calculated to be at least 40 Wm−2 and 5 °C higher than the stress-free case, respectively. For the low-SVF situation with the LAI value decreased by 25%, the physiological equivalent temperature (PET) values indicated that heat-related physiological stress increased by 1 grade in the planted areas. With the increasing surface-level ozone concentrations in the southern China region, the current study provides useful information for cities to refine design schemes and plan specifications for urban greenery to cope with the problem.

Field Study on the Microclimate of Public Spaces in Traditional Residential Areas in a Severe Cold Region of China.

As residential environment science advances, the environmental quality of outdoor microclimates has aroused increasing attention of scholars majoring in urban climate and built environments. Taking the microclimate of a traditional residential area in a severe cold city as the study object, this study explored the influence of spatial geometry factors on the microclimate of streets and courtyards by field measurements, then compared the differences in microclimate of distinct public spaces. The results are as follows. (1) The temperature of a NE-SW (Northeast-Southwest) oriented street was higher than that of a NW-SE (Northwest-Southeast) oriented street in both summer and winter, with an average temperature difference of 0.7–1.4 °C. The wind speeds in the latter street were slower, and the difference in average wind speed was 0.2 m/s. (2) In the street with a higher green coverage ratio, the temperature was much lower, a difference that was more obvious in summer. The difference in mean temperature was up to 1.2 °C. The difference in wind speed between the two streets was not obvious in winter, whereas the wind speed in summer was significantly lower for the street with a higher green coverage ratio, and the difference in average wind speed was 0.7 m/s. (3) The courtyards with higher SVF (sky view factor) had higher wind speeds in winter and summer, and the courtyards with larger SVF values had higher temperatures in summer, with an average temperature difference of 0.4 °C. (4) When the spaces had the same SVF values and green coverage ratios, the temperature of the street and courtyard were very similar, in both winter and summer. The wind speed of the street was significantly higher than the courtyard in summer, and the wind speed difference was 0.4 m/s.

Analysis of the urban surface thermal condition based on sky-view factor and vegetation cover

The analysis of the surface thermal condition within the urban area of Akure City, Nigeria, has been investigated in this study. Surface heat flux, which is an expression of the thermal environment was estimated from Landsat 8 satellite image based on the Surface Energy Balance Algorithm for Land (SEBAL) model. The study applied the use of sky view factor and vegetation cover in identifying the variation of the surface heat flux and Land Surface Temperature (LST) within sixteen (16) different urban sites. The surface heat flux distribution at these sites differed distinctly in magnitude and intensity according to the sky-view and surface characteristics. The areas with the highest Sensible Heat flux (H) and Land Surface Temperature (LST) were notably the areas with higher sky-view factor and lower vegetation cover abundance. Two of the sites with the lowest intensities of H and LST had sky view factors of 0.82 and 0.42. However, the areas differed in the vegetation composition; one area was a park while the other was composed of a mixture of scattered trees and grasses. Correlation analysis revealed that over the city, surface features had more contribution to the variation of heat flux as well as LST compared to the sky-view factor. The information presented in this study is essential in sustainable urban planning and adequate response to urban thermal risks associated with the changing patterns of urban geometry and land use within the region.

Application of Method for Calculating Sky View Factor Using Google Street View: Relation Between Sky View Factor and Physical Elements in Urban Space

Abstract. We applied a computation method of calculating the sky view factor (SVF) using Google Street View to Shibuya area, Tokyo, for the purpose of examining the relation between the SVF/SVF change and physical elements. The distribution of the SVF calculated by the above method was visualized, and the statistical process showed the tendency of a high SVF in quasi-residential districts and roadsides of high-graded trunk roads. The difference in the SVF change was small at 10-m intervals. The SVF change tended to be more apparent near an intersection and at different elevations.

Air Temperature Modification of an Urban Neighborhood Park in Summer

In order to investigate the effect of air temperature reduction on an urban neighborhood park, air temperature data from five inside locations (forest, pine tree, lawn, brick and pergola) depending on surface types and three outside locations (Suwon, Maetan and Kwonsun) depending on urban forms were collected during the summer 2016 and compared. The forest location had the lowest mean air temperature amongst all locations sampled, though the mean difference between this and the other four locations in the park was relatively small (0.2-0.5℃). In the daytime, the greatest mean difference between the forest location and the two locations exposed to direct beam solar radiation (brick and lawn) was 0.5-0.8℃ (Max. 1.6-2.1℃). In the nighttime, the mean difference between the forest location and the other four locations in the park was small, though differences between the forest location and locations with grass cover (pine tree and lawn) reached a maximum of 0.9-1.7℃. Comparing air temperature between sunny and shaded locations, the shaded locations showed a maximum of 1.5℃ lower temperature in the daytime and 0.7℃ higher in the nighttime. Comparing the air temperature of the forest location with those of the residential (Kwonsun) and apartment (Maetan) locations, the mean air temperature difference was 0.8-1.0℃, higher than those measured between the forest location and the other park locations. The temperatures measured in the forest location were mean 0.9-1.3℃ (Max. 2.0-3.9℃) lower in the daytime than for the residential and apartment locations and mean 0.4-1.0℃ (Max. 1.3-3.1℃) lower in the nighttime. During the hottest period of each month, the difference was greater than the mean monthly differences, with temperatures in the residential and apartment locations mean 1.0-1.6℃ higher than those measured in the forest location. The effect of air temperature reduction on sampling locations within the park and a relatively high thermal environment on the urban sampling locations was clearly evident in the daytime, and the shading effect of trees in the forest location must be most effective. In the nighttime, areas with a high sky view factor and surface types with high evapotranspiration potential (e.g. grass) showed the maximum air temperature reduction. In the urban areas outside the park, the low-rise building area, with a high sky view factor, showed high air temperature due to the effect of solar (shortwave) radiation during the daytime, while in the nighttime the area with high-rise buildings, and hence a low sky view factor, showed high air temperature due to the effect of terrestrial (longwave) radiation emitted by surrounding high-rise building surfaces. The effect of air temperature reduction on the park with a high thermal environment in the city was clearly evident in the daytime, and the shading effect of trees in the forest location must be most effective. In the nighttime, areas with high sky view factor and surface types (e.g., grass) with evapotranspiration effect showed maximum air temperature reduction. In the urban areas outside the park, the high sky view factor area (low-rise building area) showed high air temperature due to the effect of solar (shortwave) radiation during the daytime, but in the nighttime the low sky view factor area (high-rise building area) showed high air temperature due to the effect of terrestrial (longwave) radiation emitted surrounding high-rise building surfaces.

Association between Three-Dimensional Built Environment and Urban Air Temperature: Seasonal and Temporal Differences

Climate change and the urban heat island phenomenon are increasingly important issues in urban thermal environments. However, there is a lack of research on the relationship between three-dimensional built environments and air temperature. Therefore, the purpose of this study is to provide policy suggestions that could be used to improve urban thermal environments by analyzing the effect of the three-dimensional built environment of an urban space on the urban air temperature according to changes in time (i.e., season, time of day). Using data from 236 automatic weather stations (AWSs) in Seoul, Korea, this study focused on three-dimensional built environmental variables and land use variables that affect air temperature in terms of season and time. The analysis results indicate that the sky view factor and porosity were lower in urban areas, with higher sky view factor and porosity values associated with lower air temperature. This study also indicates that surface roughness is higher in urban areas, with higher surface roughness associated with higher air temperature. These results suggest that urban design practices should consider the three-dimensional built environment when planning urban development and urban regeneration projects in order to improve the urban thermal environment.

Simulation Study of Urban Residential Development and Urban Climate Change in Xi’an, China

Increased awareness of the urban heat island (UHI) effect has drawn attention to monitoring and evaluating outdoor thermal comfort in cities worldwide. Especially in China, rapid, large-scale urban development is producing urban climate change in large cities, creating other urban environmental problems such as haze weather. Currently, studies are being conducted in China to reveal the impact of urban development on urban climate change. Few studies, however, have focused on microscale urban planning styles and urban typology.High-density building development will change the urban typology, leading to changes in the urban sky view factor (SVF) and microclimate. Our previous study explored the relationship between SVF and the UHI effect by assessing the effect of SVF on the urban thermal environment. Since the energy consumed by indoor heating and air conditioning is affected by mean air temperature (Ta), a high SVF should be considered in the urban planning stage. In this study, we analyzed typical urban planning styles in China. We selected microscale residential districts in Xi’an to represent the typical urban typology of residential districts that developed during different periods and used the numerical urban simulation system ENVI-met to evaluate the impact of urban typology change on urban climate change. Using this approach, we determined the effects of building density, building styles, and vegetation system design, thus demonstrating the mechanism of urban climate change in China's larger cities. This analysis of planning styles can provide guidance for future environmental urban development.