Architectural Simulations on Spatio-Temporal Changes of Settlement Outdoor Thermal Environment in Guanzhong Area, China

Kai Xin,Jingyuan Zhao,Tianhui Wang,Weijun Gao,Qihui Zhang

doi:10.3390/buildings12030345

Abstract

This paper aims to provide data support for rural sustainable development through analyzing the spatio-temporal characteristics of the interactions of the outdoor thermal environment. The ordinary and representative rural settlements in the Guanzhong area were selected to analyze the dynamic process of the rural thermal environment through field measurements and numerical simulations. RMSE (root mean square error) and MAPE (mean absolute percentage) were used to verify the numerical simulation model, and physiological equivalent temperature (PET) was used to evaluate the outdoor thermal environment. Results show that the ENVI-met model reliably predicts the thermal environment of a rural settlement, as the air temperature and relative humidity values range of the RMSE and MAPE were 0.85–1.79 and 2.04–5.11%, respectively. Moreover, the air temperature rose by 3.08% and relative humidity dropped by 4.42% from 2003 to 2018 as the amount of artificial surfaces increased by 35.4% and the PET index gradually increased by 27.43% at daytime and 34.03% at nighttime. Furthermore, trees could improve the outdoor thermal environment significantly, mainly because the average air temperature decreased by 3.6% and relative humidity increased by 8%, and the PET index decreased by 12.4% and 13.1%, respectively, for daytime and nighttime. This case study is representative of rural settlements in the Guanzhong plain, and thus is an appeal to rural planners to pay attention to the thermal environment issues caused by increased artificial underlay surfaces and to focus on trees in rural areas.

Highlights

Urbanization itself is a complex process of rural-to-urban transformation with corresponding changes to social structures, economic structures, and way of life [1,2]
It can be clearly seen that the root mean square error (RMSE) of the air temperature between the simulation data and the measured data is from 0.85 to 1.79, and the relative humidity error is between 1.24 and 2.78
In terms of MAPE, both the air temperature and relative humidity are between 2.04% and 5.11%

Summary

Introduction

Urbanization itself is a complex process of rural-to-urban transformation with corresponding changes to social structures, economic structures, and way of life [1,2]. China has undergone an unprecedented urbanization process since the reform and opening up in 1978 [3,4]. Rapid urbanization has boosted the incomes of rural residents, and changed the rural settlement landscape in China [5]. The air temperature near impermeable ground will increase due to impermeable surfaces (concrete, etc.) promoting ground radiation compared to natural surfaces (soil, etc.) [8], especially in hot summer. Artificial surfaces change the original energy distribution balance (the decrease in latent heat and increase in sensible heat) because the thermodynamic properties of artificial surfaces are different from natural surfaces [9]

Objectives

Methods

Results

Conclusion