Urban Greenery Research Articles

Green-blue infrastructure in the built environment – sustainable and resource-saving designs for urban structures and open spaces

Urban grey infrastructure, as it generally consists of monofunctional, sealed, impervious, heating up and reflecting surfaces, has led to a series of serious challenges (urban heat stresses, loss of biodiversity, flood risks and natural hazards) decreasing urban resilience. Ongoing construction activities result in irreversible soil consumption and loss of its numerous and vital functions. However, a common understanding has been evolving that the establishment of green-blue infrastructure (GBI) supports compensating for functional losses, as they are integrative and provide pervious, absorbent, shading and non-heating up surfaces. We present a concept to holistically interconnect stand-alone approaches to improve and support constructional design for transforming green open spaces addressing specifically urban landscape construction and building greenery. The underlying state of knowledge emerges from currently four ongoing projects on advancing GBI for re-establishing ecosystem functions and diverse habitats: 1. The Circular Soil Concept targets the reuse of excavated soil materials from construction sites to produce engineered soils. These are applied as functional vegetation substrates for landscape construction and installing building greenery, saving scarce soil resources while generating large scale and vegetated areas with climate change adaptation performance. 2. The StreetTREE-Planter is designed to install urban trees in a given street infrastructure. The advanced planter systems will support extended tree lifespans, microclimatic benefits, flood protection and urban resilience. The design is based on targeted rainwater harvesting for irrigation management in alignment with water requirements and the desired microclimatic performance. 3. The GLASGrün projects generates plant-based shading designs for glass facades. As plants and their leaves do not heat up from solar radiation, vertical greenery is promising, however challenging, for green shading of glazed surfaces and for indoor and outdoor microclimatic regulation. 4. The INReS rainwater management tool was developed as a prototype web application to integrate sustainable, plant-based rainwater management systems into BIM-(Building Information Modeling)-based construction projects. It provides up-to-date design for the wider public and specific planning guidelines. In synthesis with the present and upcoming findings of these projects, a parameter-based and BIM-compatible GBI-design management tool is foreseen to better and sustainably integrate GBI systems into construction projects, and to consider the resource question.

Effects of Green Roof in Reducing Surface Temperature and Addressing Urban Heat Island in Tropical Climate of Malaysia

Urban heat island (UHI) in cities across Malaysia has worsened due to rapid development and construction. Previous research highlight temperature difference between Putrajaya and its suburban neighbouring area is as high as 5˚C. Green roofs in urban areas can be used as a green intervention strategy to reduce UHI impact by increasing air moisture and surface wetness through its plants, which consequently decreases surrounding air and surface temperature. Green roofs also provide additional insulation that reduces heat transfer into buildings, therefore reducing cooling demand and operational energy in buildings. Conventional building roofs in tropical climate have measured surface temperature up to 60˚C, compared to surrounding irrigated grass and water bodies that are measured as low as 15˚C. This paper compared surface temperatures of green roof and conventional non-green roof case studies in a tropical climate setting, to combat urban heat island effect. A triangulation technique was adopted, using a case study analysis with an in-depth structured interview and physical fieldwork investigation. The findings concluded that green roofs had significantly lower surface temperature compared to non-green flat roof. This paper provides evidence that supports green roof as a green intervention strategy in reducing urban heat island and encourage building designers to maximize under-utilized spaces of roofs to increase urban greenery coverage.

Assessing Effects of Urban Greenery on the Regulation Mechanism of Microclimate and Outdoor Thermal Comfort during Winter in China’s Cold Region

A comfortable thermal environment in outdoor spaces is beneficial to people’s physical and mental health in cold conditions during winter. Greenery can improve outdoor thermal comfort (OTC) via microclimates in winter. Multiple methods have been employed to investigate how greenery influences OTC and microclimate. However, the underlying mechanism of how microclimate participates in the regulation of the effect of greenery on OTC is unclear. To examine the mediating effect of microclimate on the relation between greenery and OTC in cold weather during winter, we conducted meteorological measurement and thermal comfort surveys in Zhengzhou, a city in China’s cold region, from 29 to 30 December 2019. Two objective greening indices from different dimensions were extracted at twelve sampling points: (1) the green view index (GVI) from horizontal normal images from people’s perspective, and (2) the tree view factor (TVF) from vertical-upward fisheye images. With microclimatic parameters as the mediators, a comprehensive multi-step mediation analysis was conducted. The regression results revealed that the GVI and TVF were negatively associated with the thermal comfort vote (TCV) (i.e., the more greenery, the less TCV, which means the more comfortable the thermal environment). Our findings show that both GVI and TVF contribute to OTC through different mechanisms in cold climatic conditions during winter. Vegetation in sight revealed by the GVI can directly regulate OTC by affecting people’s mental feelings or other factors. Air temperature (Ta), relative humidity (RH), and wind speed (Va) served as significant partial mediators for the GVI. Moreover, there was a complete mediation for TVF–OTC correlation with Ta, RH, and Va as significant mediators. The mediating effects of microclimate accounted for 81.00% for GVI and 89.02% for TVF, respectively. The GVI is propitious to the study of people’s mental health and landscape preferences, whereas TVF is suitable for studies on microclimate adaptation.

Well-Being in the Time of Corona: Associations of Nearby Greenery with Mental Well-Being during COVID-19 in The Netherlands

Nature’s mental health benefits are well-established in the literature, but there is little research on which types and characteristics of urban greenery are most relevant for mental well-being in general, and during the COVID-19 pandemic in particular. This study examined the link between having a (green) garden or a green view from the main window of the home, as well as the perceived quantity and quality of neighbourhood green areas and streetscape greenery, and the self-reported change in mental well-being since the onset of the COVID-19 pandemic. Adults residing in the Netherlands (N = 521, 67% female) completed an online survey in December 2020 and January 2021. It included items on the frequency of contact with the aforementioned outdoor spaces, as well as their quantity, natural features, and quality. Hierarchical regression analyses revealed that the quantity of the greenery mattered, but the quality was more strongly associated with well-being. In particular, well-maintained, attractive, and varied streetscape greenery was just as relevant as a garden with diverse plants. This beneficial association between streetscape greenery and mental well-being was stronger for female participants. Understanding the benefits of the different types and characteristics of urban greenery, and who they are most relevant for, can assist policymakers and planners in designing cities that promote health and resilience.

Age- and Sex-Specific Association Between Vegetation Cover and Mental Health Disorders: Bayesian Spatial Study.

BackgroundDespite growing evidence that reduced vegetation cover could be a putative risk factor for mental health disorders, the age- and the sex-specific association between vegetation and mental health disorder cases in urban areas is poorly understood. However, with rapid urbanization across the globe, there is an urgent need to study this association and understand the potential impact of vegetation loss on the mental well-being of urban residents.ObjectiveThis study aims to analyze the spatial association between vegetation cover and the age- and sex-stratified mental health disorder cases in the neighborhoods of Toronto, Canada.MethodsWe used remote sensing to detect urban vegetation and Bayesian spatial hierarchical modeling to analyze the relationship between vegetation cover and mental health disorder cases. Specifically, an Enhanced Vegetation Index was used to detect urban vegetation, and Bayesian Poisson lognormal models were implemented to study the association between vegetation and mental health disorder cases of males and females in the 0-19, 20-44, 45-64, and ≥65 years age groups, after controlling for marginalization and unmeasured (latent) spatial and nonspatial covariates at the neighborhood level.ResultsThe results suggest that even after adjusting for marginalization, there were significant age- and sex-specific effects of vegetation on the prevalence of mental health disorders in Toronto. Mental health disorders were negatively associated with the vegetation cover for males aged 0-19 years (−7.009; 95% CI −13.130 to −0.980) and for both males (−4.544; 95% CI −8.224 to −0.895) and females (−3.513; 95% CI −6.289 to −0.681) aged 20-44 years. However, for older adults in the 45-64 and ≥65 years age groups, only the marginalization covariates were significantly associated with mental health disorder cases. In addition, a substantial influence of the unmeasured (latent) and spatially structured covariates was detected in each model (relative contributions>0.7), suggesting that the variations in area-specific relative risk were mainly spatial in nature.ConclusionsAs significant and negative associations between vegetation and mental health disorder cases were found for young males and females, investments in urban greenery can help reduce the future burden of mental health disorders in Canada. The findings highlight the urgent need to understand the age-sex dynamics of the interaction between surrounding vegetation and urban dwellers and its subsequent impact on mental well-being.

Analysis of the Artistic Effect of Garden Plant Landscaping in Urban Greening.

At present, China is at an essential stage in the progress of social civilisation. At the same time, China's current economic level is developing rapidly and the level of urbanisation is also increasing. However, the uncontrolled development of urban space and excessive consumption of land resources have led to many urban ecological and environmental problems. As a result, there is an urgent need to improve the urban habitat. Plant landscaping is an important part of the urban environment. In addition, plant landscaping is also a crucial part of the visual arts and plays a key role in the shaping of urban spaces. In the context of the urban construction boom, people are increasingly demanding quality in the urban environment. Spatial scale, as a vital factor influencing the visual effect of planting, is gradually becoming a focus of landscape design. Urban greening based on plant landscape can not only improve the urban ecological environment and enhance people's quality of life but also resolve the contradiction between the demand for urban green space and the continuous reduction of urban greening land. Therefore, plant landscaping is recognised as a key step towards global sustainable development. However, according to current research and application practice, the development of urban greenery is limited and hindered by the value of plant landscaping and its applications. In addition, no comprehensive theoretical system has yet been established at the plant scale. In other words, there are still problems of scale in plant landscaping, such as unreasonable density, disproportion, and unclear hierarchy. Therefore, this paper begins with the definition of plant spatial scale in the city and analyses plant spatial types and scale characteristics from multiple perspectives, so as to establish an overall knowledge of plant landscaping. After that, through a study of the current situation of plant landscaping in cities, a quantitative analysis of the visual scale of plant space in urban squares is carried out to address the issues of plant scale design in this research. The focus of the analysis is on the scale of plants in relation to related elements. Furthermore, this study explores the influence of visual aesthetic scale and psychological scale on planting based on the functional scale of plant elements. Finally, the above quantitative analyses are applied to derive some relative data criteria and to summarise the design strategies for the spatial scale of planting in the city. The findings of this study can provide some guiding suggestions and references for the future construction of urban greenery, thus promoting the orderly development of plant landscaping in cities.

COVID 19: Are Our Green Areas Enough for People’s Well-being

Malaysians’ overall well-being, particularly in urban areas, has been seriously affected physically and emotionally due to the series of imposed lockdowns in the country. The number of mental health problems such as depression, anxiety, and loneliness has increased tremendously during the lockdown period. Various studies suggest that these mental health issues could be coped with if people are allowed to access urban greeneries and public green spaces during the pandemic. However, the degree to how adequate existing green areas are to fulfil an urban community’s needs with strict social distancing compliance is still vaguely interpreted in the literature. It is still arguable that the current 10 per cent green area requirement is still relevant to the current context of the COVID-19 pandemic. This study aims to determine the sufficient amount of green areas for people’s well-being during the pandemic, based on the local population, accessibility to green areas, and compliance with the new norm of social distancing by a minimum of one meter. Therefore, an urban neighbourhood in Iskandar Puteri, Johor, Malaysia was selected and simulated using GIS spatial analysis based on the highlighted parameters. As a result, the study found that the current size of existing green areas in the neighbourhood is insufficient in terms of compliance with the parameters, especially Malaysia’s social distancing requirements. This study could provide a platform for future planning to include pandemic risk reduction into urban planning policies, especially in the context of Malaysia, to cater to future uncertainties

A street-scale simulation model for the cooling performance of urban greenery: Evidence from a high-density city

How much can greenery cool a city remains inconclusive in literature, especially in a high-density city where plants interact with anthropogenic heat from surrounding buildings and traffic. A novel simulation model, the Urban Greenery and Built Environment, was developed to assess the time-varying interactions between plants and anthropogenic heat at street scale. The model has been evaluated using field studies in two parks in Hong Kong. A reasonably good agreement was observed between measured and predicted temperature and humidity. Sensitivity studies were then conducted to compare the cooling performances of greenery in five scenarios under various coverage ratio and climates. By covering 40% of site with greenery, a practical limit, the expected air temperature and UTCI reductions were 0.3 °C, lower than previous estimates due to limited sunlight and ground-level surfaces for planting; the cooling benefits of greenery were predicted to be higher in dry climates and lower in humid ones. In a high-density city, plants converted sensible heat into latent gains at a slower rate than the anthropogenic exhaust heat. Alternative strategies, such as breeze enhancement, water-spray and management of anthropogenic heat discharges were predicted to further help to cool the city by 3.1 °C, 6.8 °C, and 1.8 °C, respectively.

Science fiction blockbuster movies – A problem or a path to urban greenery?

Urban greenery in cities is important for human health, for resilient and sustainable cities, and for flora and fauna. The importance of urban greenery is highlighted in numerous global, national and local policies. However, the rapid increase of urban sprawl and densification globally has reduced access, availability and quality of urban greenery. According to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), cities “do not know how to incorporate nature and nature contribution to people into city planning”. Perhaps this limitation is because urban planners, architects, landscape architects (urban designers) and urban ecologist (nature conservationist) view nature in cities differently. In addition, few studies on cities focus on nature and ecology. In this paper, we highlight the need to develop new designs and nature conservation approaches that promote biodiversity in cities. Science fiction (SF) and science have a history of inspiring each other and inspiring innovative solutions. For example, SF blockbusters have affected people’s engagement in climate change. Here, we evaluate how 44 of the most viewed American SF movies depict nature in cities, including diversity of species and how characters interact with nature. We reveal that these movies tend to ignore nature in their depictions of future cities. If nature is depicted in SF it is very similar to contemporary cities with monoculture lawns and ornamental gardens. Moreover, SF movies do not depict innovative ways of including nature in cityscapes, they illustrate unrealistic settings without basic ecological functions (e.g., pollinators), and their characters do not interact with nature when nature is depicted or only frame the scene as a façade. We suggest that urban designers, urban ecologists, and SF artists collaborate to imagine how to integrate nature and biodiversity into the depictions of future cities, a strategy that could help change norms about urban greenery.

Urban-greenery demands are affected by perceptions of ecosystem services and disservices, and socio-demographic and environmental-cultural factors

Public perceptions of ecosystem services and disservices of urban greenery are critical for urban greening policies. However, few studies have explored the association between perceptions and urban-greenery demands. Using questionnaires, we surveyed 467 Hong Kong residents on a range of 68 ecosystem services and 38 disservices. Principal component analysis extracted nine factors for services and six factors for disservices. Respondents most strongly agreed with statements about the role of urban greenery in temperature and air pollution regulation, recreation, and general well-being services. The top-rated disservices were harmful plants, tree failure, and environmental hygiene issues. The perceptions were shaped by several personal background variables (including socio-demographic and environmental-cultural factors). Correlation of two indicators of urban-greenery demands, namely desired minimum greening coverage in the built-up part of the city (City-greening) and willingness-to-pay (WTP) to improve neighbourhood greenery, i.e., greenery of one’s living areas (WTP-greening), with greenery perceptions and personal background, were investigated by regression models. The extent of agreement of some services and disservices were significant predictors of City-greening, while socio-demographic factors exerted more influence on WTP-greening. Education level was a robust predictor in all WTP-greening models, while income level did not predict the positive WTP amount. Living environment and residence type were also significant predictors in different models. The linkage of personal background with urban-greenery perceptions and the differential effects of various factors on urban-greenery demands provide policy implications to maximize public benefits and secure public support for urban greening.

Whose Heritage

Whose Heritage

Extreme weather layer method for implementation of nature-based solutions for climate adaptation: Case study Słupsk

One of the most severe climate risks that is expected to affect all regions is related to stormwater. Climate models, constructed based on long-term trends, show that extreme weather events such as storms, cloudbursts and a large rise in sea level will be significant in the coming decades. Moreover, even the frequency and intensity of “normal” rainfall events, such as microbursts, are expected to be remarkably higher than today in some regions.The efficiency of urban drainage systems is affected by the land use in its whole catchment. In addition to the climate stress, there is ongoing continuous densification of urban space, resulting in more buildings and larger areas being covered with impervious surfaces. Planning decisions today approving such compaction do not consider the impacts beyond the close proximity of the land parcel. As a result, by following the current planning practices, cities are becoming extremely vulnerable to stormwater flooding (flash floods).This study presents a holistic and dynamic planning method – the Extreme Weather Layer (EWL) – that makes it possible to analyse the impact of a single development (e.g. paving a gravel parking lot with asphalt or turning an area of urban greenery into a shopping centre) on the performance of the urban drainage system and therefore on the flooding risk of the whole catchment. The EWL is based on a widely accepted drainage modelling engine coupled with GIS system and other databases which provide spatial information.Thus, the EWL combined with the systemic approach of turning from grey to green infrastructure could be a smart tool for implementing NBS solutions for stormwater management in climate adaptation in urban areas. This smart tool could indicate how much more green infrastructure is needed and which places in the city the mitigative NBS measures would help significantly.

Offering green roofs in a compact city: Benefits and landscape preferences of socio-demographic cohorts

Urbanization and densification have extended some urban greenery skyward. Understanding expectations of aboveground green space can enhance public support and benefits. We evaluated the perceived benefits and preference for landscape elements of green roofs based on a questionnaire survey of 477 Hong Kong residents using principal component and cluster analyses. Benefits on recreation and health, air quality, and microclimate were strongly expected, but ecological and hydrological benefits were inadequately recognized. Respondents strongly preferred recreational hardware facilities like seats, kiosks and footpaths, soft landscape features like lawns, attractive flowers, pergolas and hedges, and simple ornamental planting design with low-stature vegetation and low biomass structure and complexity. Tree planting was the least desired among the three planting types. Hard landscape features were the least preferred, and some groups expected water features. Preference profiles identified six clusters of respondents, with inter-cluster dissimilarity associated with socio-demographic characteristics and benefit perception. The findings suggested that public education could enhance citizens’ knowledge on benefits to secure their support of environmentally-sound green roof design and a need for the user-oriented design of green roofs to cater to specific potential users. Strategically located sited could alleviate accessibility inequality in urban green space, especially for low-income people.

Perceived biodiversity of fruit species for urban greenery in Indonesia: Case studies in Bogor, Jakarta, and Yogyakarta

Abstract. Ruwaida IP, Santosa E, Susila AD, Widodo WD, Wachjar A, Nasrullah N. 2022. Perceived biodiversity of fruit species for urban greenery in Indonesia: Case studies in Bogor, Jakarta, and Yogyakarta. Biodiversitas 23: 3166-3177. Urban greenery planning considering biodiversity scenarios is still rarely studied in Indonesia. This study aims to demonstrate edible fruit species (FS) as the scenario for urban greenery based on interviews with citizens in Indonesian cities. The study was carried out in the cities that have implemented smart city models i.e., Bogor, Jakarta, and Yogyakarta-Indonesia. Interviews were conducted in July-December 2019, involving 420 respondents. The results showed that 77.7% of all respondents agreed with the planting of FS as city greenery. In total for all cities, there were 79 species belonging to 32 families mentioned by the respondents consisting of 41 commercial and 38 underutilized FS. Each respondent was able to mention between 20.4 and 22.8 fruit species, irrespective of city. The ability to mention fruit species was affected by the respondent’s background, especially exposure during childhood to FS, frequency as a domestic tourist, mobility mode, and frequency of visiting city parks. The rationale for selecting FS was the benefit of fruit as a food source, followed by the benefit of ecology, economy, aesthetics, and health. Based on the significant cultural index, mango ranked first as the most preferred commercial fruit species, followed by rambutan, rose apple, orange, papaya, starfruit, guava, avocado, sapodilla, and longan; and for underutilized FS were shoe-button, pinang, nam nam, mulberry, cactus, canistel, cherry, and pear. Value of species richness, Shannon-Wienner, and Simpson diversity indices of FS within a city ranged 0.97 to 1.06, 3.62 to 3.83, and 0.97, respectively. Biodiversity scenarios could be useful information in the greenery planning of smart cities to coop with evolving broader environmental services.

Multifunctionality of green corridors during pandemic lockdowns: a case study of Riobamba city in Ecuador

The pandemic has demonstrated several weaknesses and inequalities in the way society live and develops within cities, such as economic losses, massive contagions, and above all, the lack of control and people's lack of awareness about the crisis. This study aims to investigate the transformation of cities with a shortage of green spaces into cities with green and sustainable planning, the association between urban greenery and physical activity during the Covid-19, and urban green corridors as a planning tool for urban green areas.
 The green corridor was born out of a social need in the face of a health crisis and the improvement of the urban environment. This research employs three methods to study: empirical judgment and experience analysis and network analysis. All those who could not cope with the lockdown exposed green and recreational spaces in Riobamba, since only 7% of those surveyed stayed at home, while 70% left their homes for green or recreational spaces within the urban area and 23% left the city. This shows how the quality of green areas can positively affect people’s behaviors during the Covid-19. This effect highlighted the preservation of natural areas, urban reforestation, and re-naturalization of spaces. The urban green corridor is a system that connects several spaces, creating two interactions: the first is how the city can provide the necessary infrastructure during a crisis, and the second is how it energizes and prioritizes the health and supply systems for urban residents, creating safe spaces for each of the city's sectors.

EFFECTS OF URBAN GREENERY ON HEALTH. A STUDY FROM REMOTE SENSING

Abstract. Global warming is causing increasing Heat Waves that affect human health. High temperatures markedly increase morbidity and mortality. Urban Heat Islands increase the effects of Heat Waves and are a serious inconvenience to human health and comfort. Cities can substantially increase local temperatures and reduce temperature drop at night. During the night, the greater thermal inertia of the central areas reduces their cooling capacity. On the other hand, it is important to highlight that urban vegetation plays a key role in adapting cities to Global Warming and Urban Heat Island. Green areas have lower temperatures than the rest of land uses and generate a cooling effect that spreads to their surroundings creating a "cool island" effect. The main objective of this paper is to establish the nocturnal land surface temperature and land surface air temperature of Barcelona Metropolitan Area (35 municipalities, 636 km2, 3.3 million inhabitants) in an episode of a nocturnal heatwave and to estimate its possible impact on health and mortality. Subsequently, nighttime temperatures are analysed in this extreme heat context to determine their spatial distribution and detect the urban landscapes that are most vulnerable to extreme night heat. Modelling of land surface temperature must reveal the elements that determine night Urban Heat Island and consequently identify actions that can be implemented at urban planning level to refresh the environment during the night and thus increase the resilience of the most vulnerable landscapes and improve residents’ health. This paper studies the effect of urban greenery and green infrastructures on Nighttime Urban Heat Island and propose climate adaptation measures and design for urban green areas to decrease high temperature in a Heat Wave context, which contributes to reducing the serious negative impacts on people's health.

Spatio-temporal monitoring of urban street-side vegetation greenery using Baidu Street View images

Street-side vegetation greenery contributes substantial health benefits for pedestrians. Multi-year street view images are expected to enable the monitoring of dynamic street-side vegetation greenery changes and the development of targeted urban landscape plans. However, the potential of multi-year street view images used for the assessment of street-side vegetation greenery has not been evaluated yet. Besides, complicated urban landscapes may make it difficult to accurately quantify vegetation greenery. This study developed a framework to assess the spatio-temporal variation of street-side vegetation greenery using the Baidu Street View images and a new Vegetation Greenery Index (VGI). The proposed analytical framework was applied to Tai’an city, a highly populated city where urbanization has been rapid in China. The level of vegetation greenery estimated using the proposed framework was compared with ground truths randomly collected at sampling sites along the road networks in 2014 and 2019 to assess the applicability. Results demonstrated that the proposed VGI method could accurately quantify street-side vegetation greenery. The comparison of multi-year VGI layers could identify locations where vegetation greenery substantially changed and quantify the overall change in urban greenery. Vegetation greenery estimates were well agreed with the ground truths. Spatio-temporal variations in the urban vegetation greenery were attributed to trees that were newly planted or removed, the natural growth of the existing vegetation, and new building construction. The proposed framework is expected to be a useful tool to evaluate urban vegetation greenery and help urban landscape planning.

Investigating pedestrian-level greenery in urban forms in a high-density city for urban planning

The understanding of pedestrian-level greenery across urban forms in built environment configurations in high-density cities is insufficient. We conducted a citywide investigation of urban greenery from the pedestrian perspective by developing a deep learning technique to extract greenery from fisheye images generated from Google Street View images in Hong Kong. Relying on open-source data, we compared pedestrian-level greenery measurements with the satellite-based normalized difference vegetation index (NDVI) in diverse urban forms represented by local climate zone classes. Street greenery was spatially variant, and low greenery was found predominantly in private residential and commercial/business lands in high-density areas. Pedestrian-level measurement and the NDVI were strongly correlated, but the inconsistency between them increased from high- and mid-rise forms to low-rise forms and from compact forms to open forms. We also demonstrated the idea of integrating nearby street greenery with spatial information on population and urban morphology for inequality analysis. Potential implications for urban planning are provided. The findings linking street greenery with urban morphology are useful for urban and greenery planning in climate-resilient, sustainable, and healthy cities. Our analytical approach using open-source data is transferable to other high-density cities.

Synchronous management of public green spaces: The case of Imam Abdulrahman bin Faisal University’s eastern campus – Dammam, Saudi Arabia

The scarcity of water available for landscape irrigation is a great challenge facing urban greenery and landscaping initiatives in arid and semi-arid regions. The Imam Abdulrahman bin Faisal University (IAU) has established a new campus on 3,2000,000 M2 of land extended to the eastern coast of the Arabian Gulf. Since moving to the Eastern Campus in 2014, the IAU has been working hard to increase the green spaces to minimize the environmental impact of harsh climate, hard surfaces, and building masses. In its endeavor to achieve this goal, the management of landscape plant materials and irrigation systems has not kept pace with the development of the campus. Almost 800 M3/day of irrigation water has been pumped into the system however it fails to maintain good quality landscape plants. As a result, green spaces suffer great degradation especially during hot months due to insufficient irrigation management and other factors. This study is an attempt to explore the relationship between the expansion of green spaces on the IAU’s Eastern Campus and their irrigation requirements. It applied the investigative analytical method to study and analyze the green spaces elements and their daily water budget, which led to the proposal of a synchronous management approach balancing the amount of water available for irrigation purposes and the qualities and expansion of landscape plant materials. The study found that applying the required water budget to plants since their establishment on their permanent locations is a waste of available resources, but it must be gradually increased based on the plant's size, its growth rate, and seasonal changes. However, a synchronous management approach is required to ensure that good quality landscapes are maintained while using limited available resources.

The influence of urban street-side greenery on people’s visual preference

This study purposed to identify urban street-side greenery’s effect on people's preferences towards streets in Malang town, Indonesia. Nine samples of streets were randomly selected based on greenery conditions and street typologies. Thirty participants for each street systematically selected came to a total of 270 respondents. The research instrument was a questionnaire with photos of the nine streets as stimuli to explore people's preferences towards street-side greenery based on six street greenery variables and two street conditions using multiple rating scales. The data analyses employed a descriptive statistic to determine people's preferences and multiple regression analysis to identify street greenery attributes that influence people's visual preference of the street. The results show that all street greenery attributes significantly influence people's preferences (p .05). As a whole, street-side greenery attributes, i.e., plant height, green street median, vegetation arrangement, the distance between trees, tree and vegetation species, and the number of trees, determine around 17.2% of urban street visual preferences. Among those street greenery qualities, the number of trees, vegetation arrangement, and green street median existence have the most influence on people's visual preferences. However, other than street greenery attributes, the street conditions (i.e., street width and the sidewalk width) significantly contribute to people's preference. It accounts for around 49.4% of the visual preference of the street.