scholarly journals Analysis of Cooling and Humidification Effects of Different Coverage Types in Small Green Spaces (SGS) in the Context of Urban Homogenization: A Case of HAU Campus Green Spaces in Summer in Zhengzhou, China

Atmosphere ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 862
Author(s):  
Huawei Li ◽  
Handong Meng ◽  
Ruizhen He ◽  
Yakai Lei ◽  
Yuchen Guo ◽  
...  

In the context of global warming, more and more cities are experiencing extreme Urban Heat Island (UHI) effects and extreme weather phenomena, but urban green spaces are proven to mitigate UHI. Most of UHI’s research focuses on the large scale and uses remote sensing methods, which do not reflect the dynamic characteristics in detail and do not detect internal influencing factors of the green space cooling effect. Therefore, this study focused on Small Green Spaces (SGS), carrying out the measurement of the meteorological parameters (temperature, relative humidity, wind direction, wind speed, photosynthetic radiation) of the 16 sites in four types of coverage (Impervious surface; Shrub-grass; Tree-grass; Tree-shrub-grass) in a university campus. At the same time, the coverage characteristic parameters, such as Canopy Density (CD), Leaf Area Index (LAI), Photosynthetically Active Radiation (PAR), Mean Leaf Angle (MLA), of each plot were analyzed and compared. The results showed that there were significant differences in temperature among different coverage types in SGS. The biggest difference was concentrated in the noon period when solar radiation is strongest during the day. The difference between the four types of coverage with vegetation at night was small. The maximum air temperature difference among the four types could reach 8.9 ℃ and the maximum relative humidity difference was 28.5%. The cooling effect of the multi-layer vegetation-covered (Tree-shrub-grass) area was the largest compared to the impervious surface, indicating that tree cover was the core factor affecting the temperature. Temperature and relative humidity had a close correlation with surface coverage types and some plant community characteristics (such as CD and LAI). The cooling and humidifying effects of plants were also related to PAR and leaf angle. The results provide suggestions for green space management and landscape design.

2021 ◽  
Author(s):  
Constanza Arévalo ◽  
Juan David Amaya-Espinel ◽  
Cristián Henríquez ◽  
José Tomás Ibarra ◽  
Cristian Bonacic

Abstract Urban green spaces provide natural habitat for birds in city landscapes, yet the effects of noise and surrounding urban morphology on bird community structure and distribution are not well understood in Latin America, the second most urbanized region in the world. Santiago, Chile, located in the epicenter of the single portion of Mediterranean ecosystem in South America, is subject to extensive urbanization seen throughout Latin America. We examined the role of 65 urban green spaces (6 large: PAR and 59 small: SGS) in harboring native birds during winter 2019, analyzing the quality of green areas in terms of vegetation (i.e. NDVI, native vegetation, and tree cover), exotic bird species, noise levels, and surrounding urban matrix (i.e. building height and cover). Significantly higher noise levels were detected in SGS, along with significantly greater exotic bird (n=4) richness and abundance than PAR, which possessed significantly greater native bird (n=25) richness and abundance. Native birds were more abundant than exotic birds in green spaces with average noise levels < 52 dB and average NDVI > 0.5. Occupancy models indicate that green space occupancy by 50% of modeled native bird species was influenced by maximum noise levels, playing a larger role than vegetation (30%) and the urban matrix (0%). We stress the importance of developing networks of large green spaces in rapidly urbanizing regions, with abundant tree cover, surrounded by smaller urban morphology, and regulating noise levels to ensure the preservation of native bird communities in cities, particularly those of greater conservation value.


2022 ◽  
Author(s):  
Constanza Arévalo ◽  
Juan David Amaya-Espinel ◽  
Cristian Henríquez ◽  
José Tomás Ibarra ◽  
Cristián Bonacic

Abstract Urban green spaces provide natural habitat for birds in urban landscapes, yet the effects of noise and surrounding urban morphology on bird community structure and distribution are not well understood in Latin America, the second most urbanized region in the world. Santiago of Chile is the single city belonging to the Mediterranean ecosystem in South America and is subject to extensive urbanization as seen throughout Latin America. We examined the role of 65 urban green spaces (6 large: PAR and 59 small: SGS) in harboring native birds during winter 2019, analyzing the quality of green areas in terms of vegetation (i.e. NDVI, native vegetation, and tree cover), exotic bird species, noise levels, and surrounding urban matrix (i.e. building height and cover). Significantly higher noise levels were detected in SGS, along with significantly greater exotic bird (n=4) richness and abundance than PAR, which possessed significantly greater native bird (n=25) richness and abundance. Native birds were more abundant than exotic birds in green spaces with average noise levels < 52 dB and average NDVI > 0.5. Occupancy models indicate that green space occupancy by 50% of modeled native bird species was influenced by maximum noise levels, playing a larger role than vegetation (30%) and the urban matrix (0%). We stress the importance of developing networks of large green spaces in rapidly urbanizing regions, with abundant tree cover, surrounded by smaller urban morphology, and regulating noise levels to ensure the conservation of native bird communities in cities, particularly those that are threatened.


Author(s):  
Julia Rehling ◽  
Christiane Bunge ◽  
Julia Waldhauer ◽  
André Conrad

Public green spaces have a high potential for a positive impact on people’s health and wellbeing, especially in urban areas. Studies on environmental justice indicate socially unequal access possibilities to urban green spaces. This article presents results on associations between individual socioeconomic position (SEP) and walking time from home to public green spaces in young people living in urban areas with more than 20,000 inhabitants in Germany. Data were derived from the German Environmental Survey for Children and Adolescents 2014–2017 (GerES V), the environmental module of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS Wave 2). The sample comprises 1149 participants aged 3 to 17 years. A total of 51.5% of the participants reach a public green space on foot within five and 72.8% within ten minutes from home. The lower the participant’s SEP, the longer the walking time. Logistic regression models controlling for age group, sex, migration background, and region of residence show that participants with a low SEP have a significantly higher risk (odds ratio = 1.98; 95% confidence interval: 1.31–2.99) of needing more than ten minutes to walk from home to a public green space than participants with a high SEP. GerES V data indicate that young people living in urban areas in Germany do not equally benefit from the health-promoting potential of green spaces, which is an important aspect of environmental health inequalities.


2018 ◽  
Vol 10 (11) ◽  
pp. 3917 ◽  
Author(s):  
K Rahman ◽  
Dunfu Zhang

This study estimates the factors affecting socially vulnerable groups’ demand for and accessibility levels to green public spaces in Dhaka City, Bangladesh. Dhaka is a high-density city with one of the lowest levels of green space per capita in the world. Dhaka has just 8.5% of tree-covered lands, while an ideal city requires at least 20% of green space. Urban public green space provides a healthy environment to city dwellers as well as ecological soundness. This study aims to examine the effects of population density and size of a community area (Thana) on the social demand for and accessibility to green parks. To determine the socially vulnerable group demand index, this study used demographic data from the National Population and Housing Census 2011 conducted by the Bangladesh Bureau of Statistics. This study used geographical data extracted from Google Earth Pro to measure accessibility levels, and additionally analyzed geographical data with ArcGIS 10.0 and Google Earth Pro. We drew radius circles using Free Map Tools to measure time-distance weighted scores from community areas to urban green spaces. The results show that the large population size of socially vulnerable groups creates very high demand at the score of 0.61 for urban green public parks and small-sized, high-density community areas generate very good accessibility at 2.01% to green public spaces. These findings are highly useful to policymakers, urban planners, landscape engineers, and city governments to make a compact city sustainable, inclusive, and resilient. Moreover, the notion of a “smart city” might be a smart solution in order to manage Dhaka Megacity sustainably in this modern technological age.


Land ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1197
Author(s):  
Yuyang Zhang ◽  
Qilin Wu ◽  
Lei Wu ◽  
Yan Li

Green space exposure is beneficial to the physical and mental health of community residents, but the spatial distribution of green space is inequitable. Due to data availability, green equality or justice studies typically use administrative units as contextual areas to evaluate green spaces exposure, which is macro-scale and may lead to biased estimates as it ignores fine-scale green spaces (e.g. community gardens, lawns), that community residents are more frequently exposed to. In this study, we used the community as the unit of analysis, considered the green exposure of community residents in their daily social and physical activities, obtained data on three types of green spaces including fine-scale green spaces in the communities, surrounding large-scale parks and streetscape images. We propose a series of metrics for assessing community green equity, including a total of 11 metrics in three major categories of morphology, visibility and accessibility and applied them to 4,544 communities in Beijing urban area. Through spatial visualization, spatial clustering, radar plots, and correlation analysis, we comprehensively analyzed the equity of green space at the community scale, identified the cold and hot spots of homogeneity, and then analyzed the equity of green space among regions under the urbanization process. The measurement results of these metrics showed that there are large differences and complementarities between different categories of metrics, but similarities exist between metrics of the same category. The proposed methodology represents the development of a green space evaluation system that can be used by decision makers and urban green designers to create and maintain more equitable community green spaces. In addition, the large-scale, comprehensive and fine-scale green space measurement of this study can be combined with other studies such as public health and environmental pollution in the future to obtain more comprehensive conclusions and better guide the construction and regeneration of green spaces.


2021 ◽  
Author(s):  
Xiangdong Xiao ◽  
Lulu Zhang ◽  
Yimei Xiong

Abstract Continuous urban development leads to urban heat island effects. Research suggests that urban green spaces can help effectively reduce urban heat island effects in the summer. Previous studies have mainly focused on the influence of different underlying surfaces on air cooling and humidification. There is a lack of in-depth research on the relationship between park structure and microclimatic effects. Here, we examined the main landscape parameters of green spaces in 15 parks located in Suzhou Industrial Park (SIP) with a subtropical maritime monsoon climate zone during the summer to analyze their influence on the microclimate. The average cooling and humidifying effect of medium-size green spaces was most significant during high-temperature hours in the daytime. When the distance to a water body was the same, the average cooling and humidifying effect ranked as follows: large-size green space > small-size green space > medium-size green space. We explored the mechanisms of the local cooling and humidifying effects of woodland and water areas in parks by numerical simulations. The significance of the cooling and humidifying effects of water areas of different shapes was as follows: annular water > massive water > banded water. This confirmed that the shape and size of water areas within a green space has a significant influence on local cooling and humidification.


2021 ◽  
Vol 263 (1) ◽  
pp. 5780-5791
Author(s):  
Omid Samani ◽  
Verena Zapf ◽  
M. Ercan Altinsoy

Urban green spaces are intended to provide citizens with calm environments free of annoying city noises. This requires a thorough understanding of noise emission and related exposure to sounds in green spaces. This research investigates noise perception in various spots in an urban green space. For this purpose, the study has been conducted in the grand garden of the city of Dresden. The garden covers 1.8 square kilometers of various landscapes, including water streams, park railways, fountains, bridges, roads for bicycles and pedestrians etc. Noise perception was investigated at eleven spots with emphasis on four noise types: nature noise, human noise, traffic noise, and technical noise. In parallel, audio-visual recordings were conducted for each spot to identify the connection between the perceptual measures and the psychoacoustic parameters. These spots are categorized based on the resulting perception and psychoacoustic parameters. In addition, the visual effect of each spot on final perception is investigated. Eventually, annoyance for each spot is identified based on the corresponding participants' perception and is associated with the relevant psychoacoustic parameters.


2018 ◽  
Vol 15 ◽  
pp. 77-86
Author(s):  
Mahendra Singh Thapa ◽  
Gokul Poudel

Urban green spaces are integral part of urban infrastructure. Green spaces can offer a number of benefits ranging from inner spiritual to outer materialistic values. Available green spaces in particular area especially in urban places need to be identified and located properly with scientific way and means so that we can use those places in emergency caused by natural or human induced hazards. This study has tried to measure the green space available for people dwelling in Butwal Sub-Metropolitan City of Nepal. An attempt was made to quantify green spaces in urban environments from Landsat 8 OLI imageries using object-oriented approach and field verification. The study concluded that the total green space available in Butwal Sub-Metropolitan City is 86.37 km2 i.e., around 86% of total municipal area and per capita green space is around 623 m2.


Challenges ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 36
Author(s):  
Jennings

Urban green spaces can facilitate positive social interactions in numerous ways. These interactions may lead to the development of social cohesion among city dwellers. This article provides a viewpoint on the potential role that the presence of green space and volunteering can play in the construct of social cohesion. Specifically, the article focuses on one aspect of social cohesion, volunteerism, as a way to illustrate the immense potential of social cohesion to link health with place and the planet.


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