Mechanisms and Empirical Modeling of Evaporation from Hardened Surfaces in Urban Areas.

Jinjun Zhou,Qi Chu,Zhuoran Luo,Jiahong Liu,Weiwei Shao,Yongxiang Zhang,Hao Wang

doi:10.3390/ijerph18041790

Abstract

Urban evaporation, as an essential part of local water vapor resources in urban areas, has often been underestimated. One possible reason is that the evaporation of urban hardened surfaces is seldom considered and poorly understood in urban evaporation estimation. This study focused on the mechanisms and calculation of evaporation on hardened surfaces in urban areas. Experimental monitoring was used to monitor the processes and characteristics of evaporation on hardened surfaces. Mathematical models based on water quantity constraints were built to calculate evaporation of hardened surfaces. The results showed that: The interception abilities for rainwater and rainfall days of impervious hardened surfaces determine their evaporated water amount, which means no water, no evaporation for the impervious surfaces. The greater evaporation of artificial sprinkling on roads happened in fewer days of rainfall and frost. The evaporation of pervious hardened ground is continuous compared to the impervious surface. Its soil moisture in the sub-layer of permeable concrete decreases periodically with a period of one day. The evaporation of hardened surfaces occupies 16–29% of the total amount of evaporation in the built-up areas in cities. Therefore, the hardened surface evaporation has great significance on the urban hydrological cycle and urban water balance.

Highlights

Urbanization has led to the expansion of urban population and urban hardened surface area [1,2]
Impervious hardened surfaces will intercept rain water, and this part rain water all evaporates into air
There will be municipal artificial sprinkling, and this part of the water contributes to urban evaporation

Summary

Introduction

Urbanization has led to the expansion of urban population and urban hardened surface area [1,2]. Hardened surfaces refer to the artificial ground or roof structure which are paved with stone, brick, concrete, asphalt and so on. Typical hardened surfaces include asphalt road, cement ground, brick pavement, and building roof, which are the main underlying surfaces in cities. By the end of 2019, the proportion of urban population and hardened surfaces in cities were both above 60% in China [3]. Urban hardened surfaces bring great changes to the urban environment and hydrological process [1,4,5]. The urban hardened surface will change the urban thermal comfort and influence public health [9,10]

Methods

Results

Discussion

Conclusion