scholarly journals Effects of Green Space Patterns on Urban Thermal Environment at Multiple Spatial–Temporal Scales

2020 ◽  
Vol 12 (17) ◽  
pp. 6850
Author(s):  
Yu Song ◽  
Xiaodong Song ◽  
Guofan Shao

Land use/land cover (LULC) pattern change due to human activity is one of the key components of regional and global climate change drivers. Urban green space plays a critical role in regulating urban thermal environment, and its cooling effect has received widespread attention in urban heat island (UHI) related studies. To fully understand the effects of the landscape pattern of an urban green space in regulating the urban thermal environment, it is necessary to further study the thermal effects of the landscape pattern of the urban green space and its characteristics under varied spatial–temporal scales. In this paper, we took the urban core area of Hangzhou City as the study area and analyzed the relationships between the landscape metrics of the urban green space and land surface temperature (LST) under varied spatial scales by using correlation analysis and redundancy analysis (RDA) methods. Multi-temporal Landsat 8 thermal infrared sensor data were used to retrieve the spatial and temporal dynamics of LSTs in four consecutive seasons, and the land use classification was interpreted using SPOT (Systeme Probatoire d’Observation de la Terre) satellite imagery. The results showed that landscape dominance metrics—e.g., percentage of landscape (PLAND) and largest patch index (LPI)—were the most influential factors on urban LST. The spatial configuration of urban landscape, as represented by the fragmentation and aggregation and connectedness, also showed significant effects on LST. Furthermore, landscape pattern metrics had varied spatial scale effects on LST. Specifically, the landscape dominance metrics of urban forest showed an increased influence on LST as the spatial scale increased, while for urban water, the trend was opposite. These findings might have some practical significance for urban planning about how to spatially arrange urban green space to alleviate UHI at local and regional scales.

2021 ◽  
Vol 13 (17) ◽  
pp. 3415
Author(s):  
Haipeng Ye ◽  
Zehong Li ◽  
Ninghui Zhang ◽  
Xuejing Leng ◽  
Dan Meng ◽  
...  

Deterioration of the urban thermal environment, especially in megacities with intensive populations and high densities of impervious surfaces, is a global issue resulting from rapid urbanization. The effects of landscape patterns on the urban thermal environment within a single area or single period have been well documented. Few studies, however, have explored whether the effects can be adapted to various cities at different urbanization stages. This paper investigated the variations of these effects in the five largest and highly urbanized megacities of China from 1990 to 2020 using various geospatial approaches, including concentric buffer analysis, correlation analysis, and hierarchical ridge regression models. The results indicated that the effects of landscape patterns on the urban thermal environment were greatly variable at different urbanization stages. Although landscape composition was more important than landscape configuration in determining the urban thermal environment, the standard coefficients of composition metrics continuously decreased from 1990 to 2020. However, configuration metrics, such as patch density, edge density, and shape complexity, could affect the land surface temperature (LST) to a larger extent at the highly urbanized stage. The urbanization process could also affect the cooling effect of urban green space. At the initial stage of rapid urban expansion in approximately 2000, urban green space explained the most variation in LST, with a value as high as 10%. To maximize the cooling effect, the spatial arrangement of urban green space should be highlighted in the region that was 10–15 km from the city center, where the mean LST experienced a significant decline. These results may provide deeper insights into improving the urban thermal environment by targeted strategies in optimizing landscape patterns for areas at different urbanization stages.


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.


Author(s):  
Yashaswini S* ◽  
Shankar B

Improving the Accessibility of Urban Green Space (UGS) is an integral part of city planning system. People with better access to green space enjoy a wide range of health benefits. Therefore, it is a crucial element to be taken care and nourished in a land use framework. Mysore City is one of the planned large cities in India. The City had a population of about 0.9 million in 2011 and it is estimated to cross the million mark by 2021. There is a growing consciousness on health and wellbeing among the people resulting an increasing demand for urban green spaces both at neighbourhood and city levels. The accessibility helps in promoting usage of UGS and maintaining the balance in environment within the city areas. The main aim of this paper is to study the existing scenario of the UGS within the planning district-12 and to analyse the green space accessibility. The land use of Mysuru city is analysed to understand the city and the micro level land use analysis of Planning district-12 is made. The existing scenario of the UGS within the study area and its accessibility is analysed using different accessibility indicators. Considering the key findings, issues and challenges are identified. Later the suggestions and recommendations for the identified issues is proposed to enhance the green spaces quality and accessibility at neighbourhood levels. The Accessible Natural Green space Standard (ANGst) type of accessibility analysis has been carried to know UGS functionality. Henceforth urban green space network at Planning District levels (local levels) in the City of Mysuru is prepared as a model which can be implemented to the city as whole at the later stages


Land ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 453
Author(s):  
Marcin Feltynowski ◽  
Jakub Kronenberg

Urban green spaces are frequently presented as being important for urban quality of life and urban development in general, but more detailed interpretations and discussions are typically confined to large urban centers, the so-called first- and second-tier cities. Not enough attention has been paid to smaller urban units, the third-tier towns. The main goal of this article is to investigate the share and types of urban green spaces in five selected towns in Poland. We compare different sources of data based on satellite imagery and land-use maps with those used in public statistics, to check whether town authorities are managing all potential green spaces or only a selected part of them. We find that the predominantly used data, based on what is classified as “urban green space” for the purposes of public statistics, obscure the complexity of urban green spaces and focus on the narrowly understood formally managed public green spaces (which occupy 3.5–5.7% of town areas). Meanwhile, based on other sources, such as the national land-use map (BDOT10k), Urban Atlas, and satellite imagery (Landsat 8), what is considered to be green space turns out to cover 50–80% of the town area. The latter large numbers are associated with the predominance of arable land, grasslands, and forests, overlooked in any green space management practices based on data and definitions adopted for the purposes of public statistics. The situation found in our five case study towns resembles that identified in larger cities in Poland, and it exhibits the inadequacy of public statistics definitions and the related management practices, hindering the management of urban green spaces as an interconnected system of urban green infrastructures.


2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Nhat-Duc Hoang ◽  
Xuan-Linh Tran

Information regarding the current status of urban green space is crucial for urban land-use planning and management. This study proposes a remote sensing and data-driven solution for urban green space detection at regional scale via employment of state-of-the-art metaheuristic and machine learning approaches. Remotely sensed data obtained from Sentinel 2 satellite in the study area of Da Nang city (Vietnam) are used to construct and verify an intelligent model that hybridizes Marine Predators Algorithm (MPA) and support vector machines (SVM). SVM are employed to generalize a decision boundary that separates features characterizing statistical measurements of remote sensing data into two categories of “green space” and “nongreen space”. The MPA metaheuristic is used to optimize the SVM training phase by identifying an appropriate set of the SVM’s hyperparameters including the penalty coefficient and the kernel function parameter. Experimental results show that the proposed model which processes information provided by all of the Sentinel 2 satellite’s spectral bands can deliver a better performance than those obtained from the model based on vegetation indices. With a good classification accuracy rate of roughly 93%, an F1 score = 0.93, and an area under the receiver operating characteristic = 0.98, the newly developed model is a promising tool to assist local authority to obtain up-to-date information on urban green space and develop plans of sustainable urban land use.


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