scholarly journals The Sensitivity of Urban Heat Island to Urban Green Space—A Model-Based Study of City of Colombo, Sri Lanka

Atmosphere ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 151 ◽  
Author(s):  
Dikman Maheng ◽  
Ishara Ducton ◽  
Dirk Lauwaet ◽  
Chris Zevenbergen ◽  
Assela Pathirana

Urbanization continues to trigger massive land-use land-cover change that transforms natural green environments to impermeable paved surfaces. Fast-growing cities in Asia experience increased urban temperature indicating the development of urban heat islands (UHIs) because of decreased urban green space, particularly in recent decades. This paper investigates the existence of UHIs and the impact of green areas to mitigate the impacts of UHIs in Colombo, Sri Lanka, using UrbClim, a boundary climate model that runs two classes of simulations, namely urbanization impact simulations, and greening simulations. The urbanization impact simulation results show that UHIs spread spatially with the reduction of vegetation cover, and increases the average UHI intensity. The greening simulations show that increasing green space up to 30% in urban areas can decrease the average air temperature by 0.1 °C. On the other hand, converting entire green areas into urban areas in suburban areas increases the average temperature from 27.75 °C to 27.78 °C in Colombo. This demonstrates the sensitivity of UHI to vegetation cover in both urban and suburban areas. These seemingly small changes are average grid values and may indicate much higher impacts at sub-grid levels.

Land ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 341
Author(s):  
Ralf-Uwe Syrbe ◽  
Ina Neumann ◽  
Karsten Grunewald ◽  
Patrycia Brzoska ◽  
Jiři Louda ◽  
...  

The quality of life in our cities critically depends on the intelligent planning and shaping of urban living space, in particular urban nature. By providing a wide range of ecosystem services (ES), urban nature essentially contributes to the well-being of city dwellers and plays a major role in avoiding common diseases through its positive impact on physical and mental health. Health is one of the most important factors underlying human welfare and is, thus, vital to sustainable development. The ES of urban green space provide other social-cultural functions alongside public health, for example by fostering environmental justice and citizenship participation. Thus, they should always be considered when searching for solutions to urban problems. The aim of this research was to determine the impact of green areas in three selected cities on the health and well-being of people by self-reporting of green areas’ visitors. To this end, we posed the research question: which types and characteristics of urban green space are most appreciated by city dwellers? Based on our findings, we have drawn up recommendations for practices to promote better living conditions. We have also pinpointed obstacles to and opportunities for leisure time activities as well as ways of supporting the public health of citizens.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 813
Author(s):  
Hui Dang ◽  
Jing Li ◽  
Yumeng Zhang ◽  
Zixiang Zhou

Urban green spaces can provide many types of ecosystem services for residents. An imbalance in the pattern of green spaces leads to an inequality of the benefits of such spaces. Given the current situation of environmental problems and the basic geographical conditions of Xi’an City, this study evaluated and mapped four kinds of ecosystem services from the perspective of equity: biodiversity, carbon sequestration, air purification, and climate regulation. Regionalization with dynamically constrained agglomerative clustering and partitioning (REDCAP) was used to obtain the partition groups of ecosystem services. The results indicate that first, the complexity of the urban green space community is low, and the level of biodiversity needs to be improved. The dry deposition flux of particulate matter (PM2.5) decreases from north to south, and green spaces enhance the adsorption of PM2.5. Carbon sequestration in the south and east is higher than that in the north and west, respectively. The average surface temperature in green spaces is lower than that in other urban areas. Second, urban green space resources in the study area are unevenly distributed. Therefore, ecosystem services in different areas are inequitable. Finally, based on the regionalization of integrated ecosystem services, an ecosystem services cluster was developed. This included 913 grid spaces, 12 partitions, and 5 clusters, which can provide a reference for distinct levels of ecosystem services management. This can assist urban managers who can use these indicators of ecosystem service levels for planning and guiding the overall development pattern of green spaces. The benefits would be a maximization of the ecological functions of green spaces, an improvement of the sustainable development of the city, and an improvement of people’s well-being.


Author(s):  
Kaili Chen ◽  
Tianzheng Zhang ◽  
Fangyuan Liu ◽  
Yingjie Zhang ◽  
Yan Song

In recent years, the interest in the relationship between urban green space and residents’ mental health has gradually risen. A number of researchers have investigated the causal relationship and possible mediators between the two, although few have summarized these mediators. For this reason, we searched for relevant studies and filtered them by criteria and quality score, and analyzed the mediators and paths of the impact of urban green space on residents’ mental health. The mediators can be divided into environmental factors, outdoor activity, and social cohesion. From the perspective of heterogeneity, both individual characteristics (e.g., age and gender) and group characteristics (e.g., level of urban development and urban density) of residents are considered to be the cause of various mediating effects. Types of urban green space tend to affect residents’ mental health through different paths. Furthermore, this review discusses the details of each part under the influence paths. Finally, the policy implications for urban green space planning from three mediator levels are put forward based on an analysis of the situation in different countries.


2017 ◽  
Vol 8 (2) ◽  
pp. 1 ◽  
Author(s):  
Bernard Essel

Incorporating greenery has been a vital aspect of city planning. Landscape planning has been a vital aspect of city planning since the 19th Century. Since then, landscape planning has become a social necessity. Assessing the impact of the decline in urban green space is very important. Hence, using Kumasi as a case study largely fit due to the decline of the city’s urban green space. Based on this the study assessed the Landcover change between 2000 to 2010 and projected the Landcover/land use for 2020. It also analyzed the temperature recordings from 2000 to 2016. The result revealed that the city has lost 19.59 km2 and 33.39 km2 of forest and agriculture lands respectively. It was also projected that it will further decline to 0.7 km2 and 8.2 km2 respectively. Among the various Landcover classes, agriculture lands were the most delicate land use which suffers massive decline in acreage. Moreover, the adverse effect of the decline in green spaces has been evident in high temperatures, unattractive environment, and atmospheric pollution. In the last decade (2000-2010), the city’s temperature increased by 0.2oC but has dropped in the past six years (2010-2016). Nevertheless, it doesn’t suggest that the impact of the heat waves has reduced due to the reduction in temperature. Conversely, the impact has increased due to the absence of tree cover. Ultimately, Kumasi’s landscape has depleted and has lost a touch of vegetation, hence appropriate measure needs to be put in place. 


2018 ◽  
Vol 55 (4C) ◽  
pp. 129
Author(s):  
Nguyen Bac Giang

This paper presents the analysis of the effect of urban green space types on land surface temperature in Hue city. Data are collected with temperature monitoring results from each green space type and the interpretation of surface temperature based on Landsat 8 satellite image data to determine temperatures at different times of the year. Results showed that there was a significant correlation between types of urban green space and the surface temperature. Types of green space with a large area and vegetation indexes have a greater effect on temperature than areas with a smaller green space do. Green space types including forest green space, dedicated green space and agriculture green space have the most effect on the surface temperature. The forest area has the greatest influence on the temperature with a temperature difference of more than 1.6 degrees Celsius at 9:00 in the daytime. Besides, the results extracted from satellite images also show that the area of urban green space going to be reduced makes a contribution to increase the surface temperature of urban areas. The study results have established foundation for planning the green spaces in climate change challenges in Hue City.


2020 ◽  
Vol 12 (12) ◽  
pp. 1929 ◽  
Author(s):  
Wenhui Kuang ◽  
Yinyin Dou

Urban green space (UGS) plays a pivotal role in improving urban ecosystem services and building a livable environment for urban dwellers. However, remotely sensed investigation of UGS at city scale is facing a challenge due to the pixels’ mosaics of buildings, squares, roads and green spaces in cities. Here we developed a new algorithm to unmix the fraction of UGS derived from Landsat TM/ETM/8 OLI using a big-data platform. The spatiotemporal patterns and dynamics of UGSs were examined for 70 major cities in China between 2000 and 2018. The results showed that the total area of UGS in these cities grew from 2780.66 km2 in 2000 to 6764.75 km2 in 2018, which more than doubled its area. As a result, the UGS area per inhabitant rose from 15.01 m2 in 2000 to 18.09 m2 in 2018. However, an uneven layout of UGS occurred among the coastal, western, northeastern and central zones. For example, the UGS percentage in newly expanded urban areas in the coastal zone rose significantly in 2000–2018, with an increase of 2.51%, compared to the decline in UGS in cities in the western zone. Therefore, the effective strategies we have developed should be adopted to show disparities and promote green infrastructure capacity building in those cities with less green space, especially in western China.


Sign in / Sign up

Export Citation Format

Share Document