城市下垫面辐射热作用过程差异分析

ANALYSIS OF DIFFERENCE OF THERMAL ACTION PROCESSES IN URBAN SUBSURFACE

为了研究城市不同下垫面辐射热作用过程的差异,选取4种下垫面(草地、混凝土、铺面砖、沥青)为研究对象,测量不同下垫面反射的短波辐照度、向上的长波辐照度、地表热流强度以及空气温度、风速等环境参量。分析对比不同下垫面辐射热传递过程中的差异。结果表明:大气逆辐照度占下垫面吸收辐射热的65%以上,4种下垫面以长波辐射的形式释放热量均在75%以上;下垫面与空气间的换热主要以辐射换热的方式进行;夏季草地热稳定性最好,混凝土下垫面的热稳定性最差;冬季混凝土的热稳定性最好,铺面砖的热稳定性最差。

In order to investigate the differential process of radiant heat action among various urban underlying surfaces,four types of substrates(grass,concrete,paving blocks and asphalt)were selected as research subjects,measurements were conducted on the shortwave radiation intensity reflected by different underlying surfaces,upward long-wave radiation intensity,surface heat flux intensity,air temperature,wind speed and other environmental parameters.The differences in radiant heat transfer process between the different subbedding surfaces were analyzed and compared.The results show that atmospheric inverse radiation accounts for more than 65%of the radiant heat absorbed by the underlying surfaces,and all four types of underlying surfaces release more than 75%of the heat in the form of long-wave radiation;the heat transfer between the underlying surfaces and the air is mainly carried out in the form of radiation heat transfer;the thermal stability of grass is the best in summer,and the thermal stability of concrete underlying surfaces is the worst;the thermal stability of concrete is the best in winter,and the thermal stability of paving blocks is the worst.