| 摘要: |
| 公园在缓解城市热岛效应和提高居民
热舒适度方面发挥着重要作用。然而，公园周
边建成环境差异对不同类型公园降温效果的影
响尚缺乏研究。本研究利用局地气候区表征公
园周边建成环境特点，并根据公园内部蓝绿要
素占比划分湖泊型公园和绿地型公园，以探究
公园外部建成环境和内部特征对其降温效果的
影响。结果表明，第一组公园周边环境以开阔
型中层建筑为主，而第二组公园周边以开阔型
高层建筑为主。相对于第一组公园，第二组公
园具有更高的降温强度，二者降温强度的差异
为1.23 ℃。不同建成环境下湖泊型公园的降温
强度显著大于绿地型公园；湖泊型公园最大降
温距离集中分布在200~300 m之间，而绿地型公
园的最大降温距离具有较大离散性，对周边建
成环境变化敏感。在周边建成环境相似的条件
下，湖泊型与绿地型公园的水体占比与公园冷
岛强度之间均表现为显著正相关。当公园内水
体占比在30%~60%区间内波动时，水体占比变
化对公园冷岛强度的影响较小，而低于或超过
区间阈值时，公园冷岛强度随着单位水体占比
的增加而显著增强。研究结果对城市公园规划
布局，增强其辐射降温效果具有重要的理论指
导意义。 |
| 关键词: 建成环境 城市公园 降温效应 景
观格局 |
| DOI：10.13791/j.cnki.hsfwest.20240903003 |
| 分类号: |
| 基金项目:国家自然科学基金面上项目（42371115）；武汉市气象科技联合项目（2023020201010576） |
|
| The cooling effect of urban parks in different built environments: A case study in Wuhan |
|
CAO Qian,ZHENG Yuzhen,DENG Xiangwen,GAO Wei,XIA Zhihong
|
| Abstract: |
| With the accelerating pace of urbanization, the degradation and disappearance of natural
and semi-natural ecosystems have brought about alterations in surface thermodynamic properties.
These changes not only exacerbate the urban heat island effect, giving rise to more frequent heat
waves, but also have a profound impact on the living environment of urban residents, increasing
the probability of their exposure to extreme heat conditions. Based on reducing its own
temperature, urban parks, as integral components of the urban ecosystem, can alleviate local thermal
effects through energy exchange. Existing studies primarily examine the influence of internal and
external landscape elements on the cooling effects of urban parks. Metrics used to characterize
landscape patterns include park geometry (e.g., area and perimeter), land cover composition (e.g.,
vegetation coverage and water bodies), and building morphology (e.g., building density and floor
area ratio). However, the composition and configuration of landscape elements surrounding urban
parks are highly complex, making it difficult to adequately characterize the urban built
environment using individual metrics alone. Local Climate Zones (LCZs), defined by consistent
internal attributes such as surface cover and structural characteristics, provide a standardized
framework for representing urban landscape heterogeneity. This feature makes LCZs a critical tool
for describing the attributes of park surroundings. What is more, park types significantly influence
cooling effects, with those containing water bodies demonstrating greater cooling intensity and
broader cooling areas than those without. Water bodies offer higher cooling intensity compared to
vegetated areas. Thus, categorizing parks into lake-type and green-type park allows for a
comparative analysis of their cooling effects under varying built environments. Considering the
above, this study first characterized the built-environment features around parks using LCZs. Then,
parks with similar LCZ compositions were classified via the k-means clustering algorithm.
Subsequently, correlation and regression analyses were conducted to discuss the cooling effects of
lake-type and green-type parks in different built environments, as well as the differences between
park cool island intensity (PCII) and maximum park cooling distance (MPCD), and the key
influencing factors. Atypical samples were analyzed to clarify the impact of surrounding landscape
elements on park cooling effects. There were results indicated that the surroundings of Wuhan’s
urban parks primarily consist of open residential areas (LCZs 4 and 5) and natural or semi-natural
landscapes (LCZs D and G). The first-group parks along the Yangtze River are primarily
surrounded by open mid-rise buildings, interspersed with dense, older urban areas. The secondgroup
parks, situated in the outer areas around the first-group parks, have a higher proportion of
open high-rise buildings. Compared to the first-group parks, the second-group parks exhibit a
1.23 ℃ greater average cooling intensity, which indicates that the distribution of open high-rise
buildings in the surrounding area can moderately enhance the cooling effects of parks. Lake-typeparks demonstrate a more pronounced cooling intensity across diverse built environments compared to green-type parks. The maximum cooling distance for
lake-type parks predominantly ranges from 200 to 300 meters, while green-type parks exhibit greater variability, reflecting higher sensitivity to changes in the
surrounding built environment. Both park types show a significant positive correlation between water body proportion and park cool island intensity. Within a
water body proportion from 30% to 60%, variations in this proportion have minimal impact on park cooling intensity. However, when the proportion falls
below 30% or exceeds 60%, incremental increases cause a substantial rise in cooling intensity. Additionally, the presence of a large water body near parks tends
to diminish the cooling effects of the parks on their surroundings.
This study offers targeted planning recommendations to optimize surrounding built environments and internal park landscapes, informed by observed
differences in park cooling effects and existing research. On one hand, integrating pocket parks and fragmented green spaces around open mid-rise buildings
creates a network connecting parks and communities, mitigating built environmental differences and enhancing the radiative cooling effects of urban parks. On
the other hand, renovation and upgrade plans are guided by regression results linking park cooling intensity to water body coverage. Specifically, when water
body proportion exceeds 60%, expanding water areas is recommended to further enhance cooling intensity. This research enhances understanding of park
cooling effects in different built environments, providing insights to improve urban park planning and management to mitigate the urban heat island effect. |
| Key words: built environment urban park cooling effect landscape pattern |
