High Building Density Research Articles

REMOTE EVALUATION OF THE INFLUENCE OF VEGETATION COVER ON THE LAND SURFACE TEMPERATURE IN MAIN GEOTECHNICAL SYSTEMS OF THE LARGE CITY (BY THE EXAMPLE OF MINSK)

The influence of vegetation cover on the Land Surface Temperature (LST) was studied in main types of geotechnical systems (GTS) in Minsk (industrial, municipal, residential multi-apartment and estate, public, road, special territories, etc.). A coupled analysis of a differentiated geographic information system (GIS) and Earth remote sensing dat was used.
 Vegetation cover was assessed using the Normalized Difference Vegetation Index (NDVI), Leaf Area Index (LAI), Canopy chlorophyll content (CCC), and greening degree (%).
 The analysis revealed significant negative relationships between LST and vegetation indices when comparing all types of territories in the city (R2 varies within 0.42…0.45). Connections are weaker in the main types of GTS. The coefficients of determination LST with NDVI and the greenery degree in industrial and communal, public, residential multi-apartment and estate GTS are estimated respectively at 0.06 (0.31), 0.13 (0.25), 0.18 (0.27), and 0.28 (0.22). This indicates a
 more significant effect of technogenic elements on LST.
 Cartographic analysis of the differences between the average LST values in sections of various GTS and natural ecosystems in the urban area from the average values for the corresponding types of GTS and natural complexes revealed areas of the urban territory with increased or decreased LST values.
 The differences for the GTS and natural ecosystems vary from –3.0° to +3.0° on the most of the territory of Minsk.
 However, areas with higher differences are noted in the city. The warmest areas are mainly territories of densely built-up
 industrial zones, separate areas of residential multi-apartment and public area, located in the historical center and in the new buildings on the outskirts of the city. They are characterized by a high density of buildings, hard surfaces, a low
 greenery degree and sparse of trees and shrubs.

All-process risk modelling of typical accidents in urban hydrogen refueling stations

With the rapid development of the hydrogen industry, an increasing number of hydrogen refueling stations (HRSs) are being built in urban areas with a high density of buildings and population. As a kind of emerging clean fuel, hydrogen is also highly flammable and explosive. So, the risk of multiple accidents in urban HRSs has attracted more and more concern. In this paper, an all-Process Hydrogen Accident Risk Assessment (PHARA) model that combines event tree analysis, fuzzy Bayesian network (FBN), HyRAM, and Probit model is proposed. Based on sensitivity analysis and influence strength analysis of FBN, the critical hazards of hydrogen refueling stations are identified. The risk management priority is determined by comparing the comprehensive risk value of each functional unit of HRSs. Then, the HyRAM-based quantitative consequence analysis is carried out for the high-risk unit, and the flammable zone, fatality zone, and relative safe distances of jet fire and explosion are given in a standardized urban hydrogen refueling station. The proposed PHRAR model can provide technical support for decision-makers to prevent accidents, control risk, and optimize the layout of HRSs.

Identification of undocumented buildings in cadastral data using remote sensing: Construction period, morphology, and landscape

Buildings are the predominant objects that characterize the urban structure. For many cities, local governments establish building databases for administration as well as urban planning and monitoring. However, newly constructed buildings are often only included with a considerable time delay in the official digital cadastral maps due to processes in the acquisition of data, so-called undocumented buildings. In this regard, detecting undocumented buildings using remote sensing techniques would support the construction of update-to-date building databases with complementary information. In-depth studies on undocumented buildings and their number and location, however, are scarce. Therefore, we exploit a deep learning-based framework to detect undocumented buildings in remote sensing data and propose to derive 2D and 3D morphological parameters as well as landscape metrics., which are capable of depicting the physical forms and spatial structures of undocumented buildings. Furthermore, we exemplify the variabilities of undocumented buildings across space by the differences in morphology and landscape metrics between high and low building density regions. Upon analysis of undocumented buildings in 15 cities in the state of Bavaria, Germany, both state- and city-scale results reveal that most undocumented buildings are located in lower dense regions. This reveals that fragmentation of the landscape by building structures in the state of Bavaria is probably greater than official geospatial data currently documented.

Diurnal Selective Radiative Cooling Impact in Mitigating Urban Heat Island Effect

This study investigates the impact of diurnal radiative cooling (RC) roof panels RC roofs in mitigating the urban heat island (UHI) at city scale in comparison with high albedo roofs and concrete roofs. A validated microclimate model that embeds a building energy model is used to predict the street level temperature and thermal comfort. The effective radiative properties of RC surface are calculated using their spectral angular properties in a spectral angular atmospheric model. A case study of Beirut city with its morphology and microclimate was simulated on representative days of the year. At the peak of a humid summer day in Beirut, daytime RC roof panels resulted in a reduction in air temperature at the pedestrian level by at least 0.8°C in high building density regions enhancing outdoor thermal comfort. While the RC panel's surface temperature drop was greatest at night, its effect on the microclimate at night was negligible. At lower humidity days, the RC surface temperature was lower, however, RC impact on pedestrian level air temperature was not significantly changed. At moderate and high humidity days, RC panels yielded a similar microclimate influence on pedestrian level air temperature and outdoor thermal comfort to high-performance cool roofs.

Multiscale and multi event evaluation of short-range real-time flood forecasting in large metropolitan areas

Many large metropolitan areas are especially susceptible to floods generated by heavy, short-duration rainfall. The high density of people, buildings and infrastructure in these areas underline the importance of developing flood resilient cities and communities. An accurate real-time flood forecasting system can support decision making for launching preparedness and response actions in short-range (hours to days), and assist mitigating the disturbances caused by floods. This study explores the short-range predictive capability of a real-time flood forecast system by coupling the High-Resolution Rapid Refresh (HRRR) meteorological forecasted variables with a fully distributed hydrological model (WRF-Hydro). We provide a comprehensive analysis of short-range (36 h) forecasts for 19flood events generated by heavy rainfall in small urban and suburban watersheds (<200 km2) in the National Capital Region of the United States. Flood forecast performance are then assessed using different metrics based on observed data from U.S. Geological Survey stream gauges and reanalysis simulations using the StageIV quantitative precipitation estimates. Results show that despite the high variability of the HRRR cycle-to-cycle precipitation forecasts, the real-time flood forecast system can produce skillful forecasts with similar overall performance as the reanalysis simulations, achieving 65 % of flood detection rate. This variability had more impact on forecast skill in smaller subbasins, and flood forecasts were more consistent for longer duration and larger spatial extent rainfall. Hourly flood forecasts performed well even in smaller watersheds, correctly detecting flood occurrence with up to 34 h lead time and resulting in low peak flow magnitude and timing errors.

The cooling effects of hybrid landscapes at the district scale in mega-cities: A case study of Shanghai

Green spaces and water bodies can mitigate urban heat islands, and their cooling effects are influenced by certain characteristics and the surrounding environments. Under the influence of diverse built environments, what kinds of hybrid landscapes have a cooling effect, and which are ineffective? It is an essential issue to mitigate heat islands on the district scale, especially in mega-cities, and there remain fewer quantitative studies targeting it. This study developed a technical framework to analyze the cooling intensity and efficiency of hybrid landscapes in different built environments and took a typical mega-city, Shanghai, as an example. The samples were classified into five groups by characteristics of the built environment based on the proportions of buildings and their shadows. Furthermore, the efficient cooling intervals and the cooling intensities of hybrid landscape elements were identified based on their marginal effects. The findings showed that of all the elements, urban forests have a cooling capacity across various built environments, while water bodies and grasslands do not. In general, hybrid landscapes' cooling effects are weaker in districts with higher building density. This technical framework provides a way to mitigate heat islands in districts by planning hybrid landscapes, which can be generalized and be of practical value.

Construction of Risk Control Decision-Making Model Platform for Transportation Hub Projects under the Background of Message Technique

With the acceleration of urbanization, the construction and operation of comprehensive transportation hub have promoted the development of regional economy. However, due to its huge scale, high building density, and crowded public space, the safety status of the comprehensive transportation hub is worrying. As the node of various transportation modes, the efficient operation of the transportation system is closely related to it, but many potential risks threaten the operation safety of integrated transportation hub all the time. Therefore, risk management is an important work to ensure the safe operation of integrated transportation hub. With the deepening of technology application, the application scope of information technology has also been expanded to complete the analysis and simulation of technical scheme and construction organization process, find problems in time, and take preventive measures, so as to optimize the design scheme, reduce unnecessary losses, and speed up the construction progress. In this study, information technology is used to construct the risk control decision model of transportation hub project. According to the research, the change of the target value of the algorithm in this study is 29% better than that of the traditional algorithm, and it can get better results and get the optimal solution quickly when applied to the intelligent traffic dispatching management system.

Developing a Disaster Chain Method to Evaluate Transportation Systems: A Pilot Study of Predicting Debris Blockages in Disaster-Response Road Systems

Suitable transportation systems are vital for the functioning of urban areas. Such systems connect all major locations, including residential and commercial locations, in these areas. The effectiveness of the response of an urban area to an earthquake depends on the road system in the area. A feasible and efficient approach to evaluating the capacity of road systems to allow safe and efficient emergency transportation for affected residents in the aftermath of an earthquake should be developed. Ground transportation systems are vulnerable to earthquakes. For example, ground motion in the 1994 Northridge, 1995 Kobe, 1999 Chi-Chi, and 2018 Hokkaido earthquakes caused severe damage to urban roads and bridges. Moreover, for areas with a high building density that are prone to high-intensity earthquakes, it is important to be able to estimate the risk of road blockage caused by collapsed buildings. In the present study, a disaster impact chain was established to evaluate the probability and effects of buildings collapsing in an earthquake. This chain was used as the basis for a road blockage model and for the formulation of suitable procedures and methods for earthquake response. The results of this study indicate that buildings in strong-motion zones are severely damaged by high-intensity earthquakes. Falling debris from these buildings can lead to the blockage of rescue roads, delaying the transport of injured individuals to hospital after an earthquake. The results of this study can aid authorities in making decisions related to transportation system management during earthquake disasters.

Flood risk mapping and urban infrastructural susceptibility assessment using a GIS and analytic hierarchical raster fusion approach in the Ona River Basin, Nigeria

The topical climate change effect, along with several uncontrolled anthropogenic activities, has resulted in a global flood disaster that continues to wreak havoc on human ecology. The hydraulic and integrated modelling approaches appear to stand out in the sequence of flood risk models that have been presented because of their predictive accuracy. The former has a high probability of under predicting and the latter has a high tendency to over-predict. This study proposed a modelling approach that combines the hydraulic and integrated models using analytical hierarchical raster fusion techniques to strengthen the weaknesses of the individual models. This study seeks to undertake a flood inundation model, a runoff model, and raster fusion models using GIS and HEC-RAS rain-on-grid methods to map flood risk and perform a flood infrastructural susceptibility assessment in the Ona river basin of Ibadan city. The flood risk model's main findings revealed that 48.2% of the Ona river basin is exposed from moderate to very high flood risk. It was revealed that rainfall introduces excess stormwater into the basin, but the stream channels associated with physical features are the major influencing factors. Also vulnerable to very high flood magnitudes include places with high building, road and rail network density, and locations with a high density of damaged bridges and culverts. This study shows that the robust modelling approach presented here yielded insightful results that can be used by relevant authorities to implement flood management models and define priorities for flood catastrophe risk planning, early warning, and preparedness.

DEVELOPMENT OF AN INTERACTIVE WEB GIS APPLICATION TO SIMULATE HOUSING POTENTIAL AND DEMAND

Abstract. On 22.06.2021 the new law i.e., “Gesetz zur Mobilisierung von Bauland” (Baulandmobilisierungsgesetz) entered into force in Germany, enabling municipalities to give priority to building on inner-city open spaces at a higher building density. Especially for rural communities, where there are many underutilized properties and inner-city open spaces, there is great potential for redensification, which is addressed by the new legislation. Depending on the attractiveness of urban areas, many of the surrounding rural communities will experience an influx of population in the coming decades. The goal of this research work is to develop an interactive Web GIS application showing the housing potential and demand according to socio-demographic scenario for such a rural community. This application serves as a decision support system for the stakeholders i.e., the urban planning department of the municipality to re-densify the urban structure in a sustainable way. This work helps to build up a comprehensive geodatabase including all relevant physical, ecological, economic, and social aspects, which further locates and quantifies the potential open spaces and buildings gaps being suitable for redevelopment. Here, the housing potentials are divided into different constructional realization categories, which can be used for a realistic urban planning. The analyzed and calculated results will be visualized in a Web GIS application where the user is able to query and edit on different urban development scenarios.

Challenges of delivering TOD in low-density contexts: the Swedish experience of barriers and enablers

BackgroundTransit Oriented Development (TOD) is key to the success of public transport and for sustainable urban and regional development. Previous research has often focused on delivering TOD in urban areas with high population and building densities. This highlights the need to broaden the scope of TOD approaches to also include less densely populated areas located outside the immediate urban cores as a key concern for policy.PurposeThe aim of this paper is to increase the knowledge of how to deliver TOD in such low-density contexts.MethodsThree case studies of attempts at delivering TOD in sparsely populated areas in three Swedish city-regions are made. The data for the case studies consist of planning documents and 13 interviews with key stakeholders involved in the planning processes of the three cases.ResultsThe results show that many of the barriers and enablers are rather similar to those identified in research on TOD in much more urban contexts in other parts of the world, but the relationships between them are differently nuanced in low-density contexts. The lack of clear quantified definitions of what TOD is (or is not) allows a more flexible, site-specific understanding of TOD to emerge in this context.ResultsIt is important that a shared vision of TOD in each location is developed by the organizations involved—and such a shared vision appears to be crucial for the development to have a good chance of being delivered. Informal definitions, and individual perceptions (including those of the public) are important; and in locations that are quite “marginal” for TOD, all enablers must interact together positively for the development to have the maximum likelihood of going ahead as planned.

VISUAL CHARACTERISTICS OF PHYSICAL CHARACTERISTICS OF GAJAH MADA ROAD CORRIDOR IN DENPASAR CITY

&lt;p&gt;Economic development in urban areas indirectly changes the function of residential areas into commercial areas. Along with the development of the function of the Gajah Mada area, the threat of decreasing the visual quality of Jalan Gajah Mada as an artifact of the corridors of the Denpasar Old Town area naturally cannot be avoided. The need for increased trading space, high building density, development of economic functions that are more commercial in nature due to the demands of profit and modernization as well as a slum environment can also eliminate the visual character of the physical corridor of Jalan Gajah Mada which still retains the characteristics of Balinese architecture and the image of Kota Tua because Therefore, it is necessary to study the visual characteristics of the physical corridors of Jalan Gajah Mada so that directions regarding the arrangement should be considered in accommodating changes in the physical corridors so that they remain visually aligned. This research method is a type of descriptive research using qualitative methods. Descriptive research is a research that aims to provide a systematic, factual, accurate description of the facts and characteristics of the population so that it can produce the physical characteristics of the Jalan Gajah Mada corridor as seen from the path elements, architectural patterns and street trees that surround the corridor.&lt;/p&gt;

The effects of geographical distributions of buildings and roads on the spatiotemporal spread of canine rabies: An individual-based modeling study.

Rabies is a fatal disease that has been a serious health concern, especially in developing countries. Although rabies is preventable by vaccination, the spread still occurs sporadically in many countries, including Thailand. Geographical structures, habitats, and behaviors of host populations are essential factors that may result in an enormous impact on the mechanism of propagation and persistence of the disease. To investigate the role of geographical structures on the transmission dynamics of canine rabies, we developed a stochastic individual-based model that integrates the exact configuration of buildings and roads. In our model, the spatial distribution of dogs was estimated based on the distribution of buildings, with roads considered to facilitate dog movement. Two contrasting areas with high- and low-risk of rabies transmission in Thailand, namely, Hatyai and Tepha districts, were chosen as study sites. Our modeling results indicated that the distinct geographical structures of buildings and roads in Hatyai and Tepha could contribute to the difference in the rabies transmission dynamics in these two areas. The high density of buildings and roads in Hatyai could facilitate more rabies transmission. We also investigated the impacts of rabies intervention, including reducing the dog population, restricting owned dog movement, and dog vaccination on the spread of canine rabies in these two areas. We found that reducing the dog population alone might not be sufficient for preventing rabies transmission in the high-risk area. Owned dog confinement could reduce more the likelihood of rabies transmission. Finally, a higher vaccination coverage may be required for controlling rabies transmission in the high-risk area compared to the low-risk area.

Obtaining the NZEB target by using photovoltaic systems on the roof for multi-storey buildings

Photovoltaic (PV) systems are often used for the attainment of the NZEB (Net Zero Energy Building) target. The lack of sufficient roof area for the plant installation is, however, a common issue that limits the spread of this technology mainly in urban areas characterized by high density of buildings. This work evaluates the possibility of obtaining the NZEB target for residences and offices in Mediterranean area, using only “on site” PV systems, i.e., on the roof slab, considering different typologies of building. An in-depth analysis is provided for obtaining the building geometric parameters that would allow to establish, in the first stages of the design process and avoiding dynamic energy simulations, whether it is possible to achieve energy self-sufficiency for a certain building, taking into consideration the characteristics of the plans and the number of floors. The results show that, for the investigated square-based residential building, the energy self-sufficiency, and therefore the NZEB target, is obtainable up a maximum of 7 levels (6 levels for rectangular shape building, 5 for L and courtyard shapes), while, for another case study building intended for offices, the energy self-sufficiency is obtainable up to a maximum of 7 levels. For early design analyses about geometric characteristics and intended use of new buildings, it would be possible to use the results reported in this study to achieve a first evaluation of NZEB target attainment.

Faktor Pengaruh dalam Pembentukan Permukiman Kumuh di Desa Pohuwato Timur

&lt;p class="Abstract"&gt;&lt;em&gt;Pohuwato Timur Village is included in several slum areas in Pohuwato District. Most of the residents' houses in this area have low building quality, high building density, narrow road space, poor condition of drainage channels, and accumulation and pollution of river waste. The society also has unhealthy behavior by disposing their solid waste in the river and by using the embankment as the toilet. This research aims at investigating the condition of slums and the factors that influence the creation of slums. The results of the identification and analysis are used as guidelines in making directions for handling regional structuring. Identification of slum conditions is carried out on five indicators. The research method applies a quantitative approach and multiple linear regression analysis. Data collection techniques are questionnaires and observations. The identification results show that in general, it is a medium slum area. The results of the analysis show that residential buildings, environmental roads, drainage channels, wastewater disposal, and solid waste management simultaneously affect the slum conditions of the area, while partially only drainage and waste channels affect the slum conditions of the area. The direction of the arrangement is carried out with a pattern of handling resettlement with the principle of On-site Reblocking arrangement, as well as repair and arrangement of facilities and infrastructure of drainage and waste channels.&lt;/em&gt;&lt;/p&gt;

Research on the Spatial Heterogeneity and Influencing Factors of Air Pollution: A Case Study in Shijiazhuang, China

Rapid urbanization causes serious air pollution and constrains the sustainable development of society. The influencing factors of urban air pollution are complex and diverse. Multiple factors act together to interact in influencing air pollution. However, most of the existing studies on the influencing factors of air pollution lack consideration of the interaction mechanisms between the factors. Using multisource data and geographical detectors, this study analyzed the spatial heterogeneity characteristics of air pollution in Shijiazhuang City, identified its main influencing factors, and analyzed the interaction effects among these factors. The results of spatial heterogeneity analysis indicate that the distribution of aerosol optical depth (AOD) has obvious agglomeration characteristics. High agglomeration areas are concentrated in the eastern plain areas, and low agglomeration areas are concentrated in the western mountainous areas. Forests (q = 0.620), slopes (q = 0.616), elevation (q = 0.579), grasslands (q = 0.534), and artificial surfaces (q = 0.506) are the main individual factors affecting AOD distribution. Among them, natural factors such as topography, ecological space, and wind speed are negatively correlated with AOD values, whereas the opposite is true for human factors such as roads, artificial surfaces, and population. Each factor can barely affect the air pollution status significantly alone, and the explanatory power of all influencing factors showed an improvement through the two-factor enhanced interaction. The associations of elevation ∩ artificial surface (q = 0.625), elevation ∩ NDVI (q = 0.622), and elevation ∩ grassland (q = 0.620) exhibited a high explanatory power on AOD value distribution, suggesting that the combination of multiple factors such as low altitude, high building density, and sparse vegetation can lead to higher AOD values. These results are conducive to the understanding of the air pollution status and its influencing factors, and in future, decision makers should adopt different strategies, as follows: (1) high-density built-up areas should be considered as the key areas of pollution control, and (2) a single-factor pollution control strategy should be avoided, and a multi-factor synergistic optimization strategy should be adopted to take full advantage of the interaction among the factors to address the air pollution problem more effectively.

Estimation of the Urban Heat Island Effect in a Reformed Urban District: A Scenario-Based Study in Hong Kong

Urban heat island (UHI), a phenomenon in which land surface temperatures (LSTs) in an urban area are notably higher than that in the surrounding rural area, has made the living environment thermally uncomfortable, endangered public health, and increased the energy consumption on indoor air cooling. To develop a liveable and sustainable city, it is crucial to provide an accurate estimation of the UHI effect for urban planners when an area is transformed from bare lands to a high density of buildings. With this objective, the study develops multivariate spatial regression models based on LSTs retrieved from Landsat-8 thermal images to estimate the distribution of urban heat magnitudes (i.e., UHMs, relative temperatures referenced to rural temperature), by considering four types of causative factors that include land use and land cover, urban morphology, heat source, and local climate zones. Partial correlation analysis is performed to determine explainable variables and R2 is used to evaluate the models. Based on the constructed models and a master plan of buildings in Kowloon East, Hong Kong, the future UHM distributions are forecasted on four representative days in different seasons. Results show that the UHI effect will be mitigated significantly when the new buildings are built, suggesting appropriate urban planning regarding the urban thermal environment. We found that the considered factors can largely explain the daytime UHIs in both the built-up areas and land-cover areas. The proposed method can also be used to optimize the urban design for creating a more thermo-friendly urban environment.

Analysis of Fire Risk Assessment in South Jakarta 2021

Jakarta is the capital city of Indonesia, with a dense population of more than 10 million population. DKI Jakarta Province is divided into five city areas, including South Jakarta. South Jakarta has an area of 141,17 km2, with more than three million population. The scope for this study focused on two sub-districts in South Jakarta, which are Pasar Minggu and Jagakarsa. The objective of this study was to provide fire risk situations in two sub-districts of South Jakarta. The study used a descriptive method with non-probabilistic sampling. Data collection was performed from June 2021 to July 2021 through focus group discussions (FGDs) and filling out questionnaires. FGDs were performed to the Local Government Fire Brigade, and questionnaires were filled out by the head of the RW. The FGD guideline and questionnaire were developed based on the fire risk assessment checklist. The checklist instrument was developed by utilizing a disaster fire risk approach, including fire hazard, vulnerability, and fire protection, with twenty-two questions. The data was then analyzed using univariate analysis, bar, and spider chart. The results showed three RWs with severe-risk classification. The factors that increase the risk of fire are the use of combustible building materials and the high density of population and buildings. There were several recommendations contributed such as firefighters must have a list of the high-risk areas and develop a rescue evacuation plan, doing a routine inspection in each target area, and raising public awareness for the community to increase participation in fire risk management.

Key determinants of particulate matter 2.5 concentrations in urban environments with scenario analysis

Particulate matter (PM) 2.5 generates a variety of negative effects on health, such as heart and lung disease, asthma, and respiratory symptoms. The pollutants in the atmosphere primarily result from human activities, and, in urban settings, increases in traffic volume and higher building density can elevate the level of PM2.5. Building on previous research, this study primarily focuses on two highly developed urban areas in the Texas Triangle region: Travis County in the Austin Metropolitan Area and Harris County in the Greater Houston Area. It explores different types of urban features, such as urban structures, land use/land cover, traffic volume, and distance from roads, that affect the PM2.5 concentration in urban environments at the local scale. Throughout this study, we use various research methods, including geographically weighted regression, to estimate the PM2.5 concentrations at local scales, 3D city models to derive urban characteristics, and the random forest algorithm to predict the effects of urban features on PM2.5 concentrations. Our findings suggest that developed land use, tall buildings in dense areas, and major traffic networks are the key contributors to PM2.5. However, we also find that tree canopy cover can significantly reduce PM2.5 concentrations.

Modelling and optimizing tree planning for urban climate in a subtropical high-density city

Urban trees affect urban climate via three processes: shading effect, evapotranspiration and wind resistance. However, large differences existed in the performance of different tree species and planting patterns. To quantify the effects of trees, we extended a heat-moisture coupled model by adding a new vegetation sub-model. The results showed that tree species with a higher leaf area index (LAI) and larger crown had a better capability of transferring sensible heat to latent heat. Sparsely planted trees provided a better cooling effect than densely planting pattern. The effect of trees was examined in urban areas with different densities. The effect of trees on urban wind environment depends on the building density of urban area. The large drag force posed by a high building density weakened the drag force of trees; thus, the negative effect of trees on urban ventilation was diminished in the high-density urban area. The negative effect of trees was also discussed from the perspective of urban moisture. This study demonstrates the need of strategic tree planting in terms of urban climate and provides insights into the creation of an urban greenery plan.