Assessment of the Mechanisms of Summer Thermal Environment of Waterfront Space in China’s Cold Regions

Fan Fei,Xiaoyun Jia,Yan Wang

doi:10.3390/su14052512

Abstract

Water is an essential part of the urban ecosystem and plays a vital role in alleviating urban heat island (UHI) problems. The contribution toward UHI mitigation made by bodies of water needs to be ascertained to establish waterfront thermal environment construction standards. In this study, the thermal environment of the waterfront space of Tianjin in the cold regions of China was the research object. Through a survey including 141 valid questionnaires and the field measurement of four typical waterfront spaces in Tianjin, the thermal demand characteristics of recreational use for the waterfront environment and the influence of water on microclimate are discussed, supplemented by results from low-altitude infrared remote sensing technology, which was mainly used to obtain a wider range of infrared thermal images with higher accuracy. To improve the urban heat island effect and the quality of the ecological environment, this paper used outdoor thermal environment simulation software to quantitatively analyze the thermal environmental impact of outdoor public activity spaces around the representative urban body of water and proposes the optimization scheme of the waterfront space’s thermal environment. The results show that, based on the factors of water itself, the most economical water width was 70–80 m, and the cooling effect intensity of water had an essential correlation with the distance between the measured site and the water center. In terms of the environmental factors around the water, when the green lawn of the waterfront space was 12 m and the water shore’s geometric form was S-shaped, this could improve the cooling effect of water significantly. Waterfront activity spaces should focus on thermal comfort on the east and south water shores. It is expected that this study could provide practical implications and useful guidance for the planning and design of urban waterfront space in China’s cold regions.

Highlights

Rapid urbanization has led to a high concentration of city dwellers
High density of urban population, closely situated high-rise buildings, and an impervious underlying surface affect the urban climate environment. This is characterized by urban heat island (UHI) issues, which result in high-temperature heatwaves in summer, an increase in the number of deaths from heatstroke, and an increase in refrigeration energy consumption and greenhouse gas emissions [4,5,6]
This paper aims to explore the relevant environmental factors influencing the public space around the water from the perspective of thermal comfort, put forward the possibility of low-altitude infrared remote sensing technology to mitigate the UHI effect, establish the thermal demand characteristics of waterfront residents, and utilize thermal environment simulation software to quantitatively analyze the influencing characteristics of water on the microclimate of the waterfront’s public activity space, which helps in the development of strategies proposed for waterfront construction, based on land use and evaluation standards

Summary

Introduction

Rapid urbanization has led to a high concentration of city dwellers. According to the predictions of the United Nations and the World Bank, the proportion of the world’s population living in urban areas will grow rapidly in the 21st century, which is expected to reach 66% by 2050 [1]. A high density of urban population, closely situated high-rise buildings, and an impervious underlying surface affect the urban climate environment This is characterized by urban heat island (UHI) issues, which result in high-temperature heatwaves in summer, an increase in the number of deaths from heatstroke, and an increase in refrigeration energy consumption and greenhouse gas emissions [4,5,6]. Such manmade and meteorological factors are not conducive to the sustainable development of urban ecosystems [7,8,9,10]

Methods

Results

Conclusion