Effect of Landscape Microclimates on Thermal Comfort and Physiological Wellbeing

Binyi Liu,Robert D Brown,Zefeng Lian

doi:10.3390/su11195387

Abstract

Global climate change and intensifying heat islands have reduced human thermal comfort and health in urban outdoor environments. However, there has been little research that has focused on how microclimates affect human thermal comfort, both psychologically and physiologically. We investigated the effect of a range of landscape microclimates on human thermal comfort and health using questionnaires and physiological measurements, including skin temperature, skin conductance, and heart rate variability, and compared the results with the effect of prevailing climate conditions in open spaces. We observed that in landscape microclimates, thermal sensation votes significantly decreased from 1.18 ± 0.66 (warm–hot) to 0.23 ± 0.61 (neutral–slightly warm), and thermal comfort increased from 1.18 ± 0.66 (uncomfortable–neutral) to 0.23 ± 0.61 (neutral–comfortable). In the landscape microclimates, skin temperature and skin conductance decreased 0.3 ± 0.8 °C and 0.6 ± 1.0 μs, respectively, while in the control, these two parameters increased by 0.5 ± 0.9 °C and 0.2 ± 0.7 μs, respectively. Further, in landscape microclimates, subject heart rate variability increased significantly. These results suggest landscape microclimates improve human thermal comfort and health, both psychologically and physiologically. These findings can provide an evidence base that will assist urban planners in designing urban environments for the health and wellbeing of residents.

Highlights

Rapid urbanization, especially in developing countries, has led to massive migrations to urban areas, where the proportion of the world population is over 55% and increasing [1]
Researchers have concluded that in some situations, air temperature and solar radiation are the two most significant variables affecting outdoor thermal comfort and behavior [7,8,9]; Lenzholzer found that wind speed and experience influenced thermal comfort perceptions more than other parameters in the Netherlands [10]; and Nikolopoulou suggested psychological adaption including thermal expectation effected the use of outdoor environments [11]
For solar radiation (SR), values of the landscape space were always lower than the control (59.42 ± 54.84 vs. 497.60 ± 334.11 W/m2, p < 0.001), with the largest gap appearing around 12:00 p.m., while values decreased to their lowest and were close to each other around 18:00 p.m

Summary

Introduction

Especially in developing countries, has led to massive migrations to urban areas, where the proportion of the world population is over 55% and increasing [1]. In order to achieve the sustainability of urban areas, the increasing research interest in thermal comfort and health has heightened the need to figure out how the human body responds, both psychologically and physiologically, to different microclimates. Researchers have concluded that in some situations, air temperature and solar radiation are the two most significant variables affecting outdoor thermal comfort and behavior [7,8,9]; Lenzholzer found that wind speed and experience influenced thermal comfort perceptions more than other parameters in the Netherlands [10]; and Nikolopoulou suggested psychological adaption including thermal expectation effected the use of outdoor environments [11]. Much recent research has emphasized the physical and psychological aspects of thermal comfort by combining thermal questionnaires with microclimate parameters and thermal comfort models

Objectives

Methods

Results

Conclusion