Speaker
Description
In the context of the increasingly severe global environmental crisis, where the urban heat island effect is seriously eroding the ecological health of cities and threatening human well-being, it is extremely urgent to deeply explore the cooling mechanism of urban green spaces. (Farshid, 2019; Lin, 2021). Urban green spaces are crucial for alleviating urban overheating and play a vital role in achieving sustainable urban development if planned and utilized effectively (Soltanifard H, 2024). This research aims to address the following key questions: How to accurately assess the cooling capacity of urban parks in water network cities? How to determine the key factors and their thresholds that affect the cooling effect of parks? And how to formulate reasonable planning strategies based on the cooling performance of parks? This research focuses on the unique Lingnan water network cities in the southern China. Foshan, being a typically rapidly developing city in the Lingnan region, confronts representative environmental problems during its urbanization process, thus making the performance of its urban green spaces in coping with the heat island effect highly worthy of in-depth study.
This research takes 120 urban parks as example, aiming to comprehensively assess their cooling capabilities. To achieve this, four indicators are introduced: Park Cooling Area (PCA), Park cooling efficiency (PCE), Park cooling intensity (PCI), and Park cooling gradient (PCG) (Sun, 2024). Using the multi-ring buffer analysis tool in ArcGIS Pro, the surrounding area of each park is divided into 30 concentric buffers (extending to 900 meters), and the average temperature of each buffer is analyzed to comprehensively evaluate the cooling capacity of the park, with a particular focus on exploring the application of the law of diminishing marginal utility of cooling efficiency (Farshid, 2019; Lin, 2021).
The study is divided into five steps. First, the cooling performance of different park types is compared to determine the most effective park type (Chander, 2009; HEALEY, 2005). Second, the spatial landscape characteristics of urban green spaces are analyzed from three dimensions: morphology (covering park area, perimeter, landscape shape index, and normalized difference vegetation index), structure (such as water surface area ratio and blue-green space proportion) (Chen, 2014), and distribution (including the aggregation degree of ecological patches and water bodies). Thirdly, the Boosted Regression Tree (BRT) model is used to quantify the contribution of parks to reduce the land surface temperature under the combined influence of multiple environmental elements (Han, 2022). Fourthly, the marginal effect threshold of park characteristics on cooling is measured, and the nonlinear relationship between these factors and cooling benefits is elucidated (Friedmann, 2004; Zhang, 2024). Finally, the Geographically Weighted Regression (GWR) model is used to cluster the parks based on their cooling performance.
The results are quite enlightening. (1) In summer, despite the significant urban heat island effect, urban parks still play a significant role in cooling. From a spatial perspective, the cooling effect gradually weakens from the suburban green belt to the city center. (2) The key determinants of the cooling effect include park area, distance to the riverbank, and the proportion of blue-green space within the park. (3) Notably, green infrastructure exhibits threshold effects, and specific marginal values are determined for park area, normalized difference vegetation index, water surface area ratio, distance to the riverbank, and ecological patch aggregation degree. (4) These 120 parks are divided into five different categories based on their cooling-dominated factors.
This research not only enriches the theoretical understanding of the cooling role of urban green spaces but also provides practical insights for optimizing the planning, layout, and design of green infrastructure, thereby contributing to strengthening urban climate regulation and promoting sustainable urban development.
References
Books:
Nowak, D. J., Hutyra, L. R., & Gartner, B. L. (2018). Urban forestry and climate change: Impact on urban green space. Springer.
Mander, U., & Liivamägi, A. (2019). Green infrastructure for sustainable urban development. Routledge.
Journal article:
Chander, G., Markham, B.L., Helder, D.L., (2009) Summary of current radiometric calibration coefficients for Landsat MSS, TM, ETM+, and EO-1 ALI sensors. Remote Sens. Environ. 113 (5), pp. 893-903.
Farshid Aram, Ester Higueras García, et al (2019) Urban green space cooling effect in cities, Heliyon, 5 (4).
Han, D., An, H., et al (2022) Understanding seasonal contributions of urban morphology to thermal environment based on boosted regression tree approach. Build. Environ. 226109770.
Reports:
United Nations Environment Programme (UNEP). (2019). Greening cities: Urban green space and climate change. Nairobi: UNEP.
The World Bank. (2020). Urban green space and climate change: A review of the evidence and policy implications. Washington D.C.
Other documents:
Foshan, 2022. Overall Planning of Land and Space of Foshan City (2020-2035). In. Foshan Municipal Bureau of Natural Resources.
| Keywords | Urban Heat Island Effect; Urban Parks; Green Infrastructure; Cooling Mechanism |
|---|---|
| Best Congress Paper Award | Yes |
