Thermodynamic analysis of air-ground and water-ground energy exchange process in urban space at micro scale.
Thermodynamic analysis of air-ground and water-ground energy exchange process in urban space at micro scale.
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DOI：
10.1016/j.scitotenv.2019.133612
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发表时间：
2019-12
期刊：
影响因子：
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通讯作者：
Luo Yi;Liu Qiulin;Yang Kun;X. Wen-qing;Zhou Xiaolu;Shang Chunxue;Xu Yuanting;Zhang Yan
中科院分区：
文献类型：
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作者：
Luo Yi;Liu Qiulin;Yang Kun;X. Wen-qing;Zhou Xiaolu;Shang Chunxue;Xu Yuanting;Zhang Yan
随着我国城市化进程的加快，大量的天然下垫面被不透水面所取代，严重影响了城市的水热环境。在这项研究中，我们集中在四个典型的城市下垫面，沥青，水泥，透水砖，和草坪。基于传热学和流体力学理论，建立了太阳辐射模型和降雨对流模型，分析了不同气象条件下城市下垫面的热辐射、热传导和热对流传热过程。两种模型的拟合效果均较好：太阳辐射模型为0.89 ≤ R2≤ 0.99，1.93 °C ≤ RMSE≤2.45 °C，1.87 °C ≤ MAE ≤ 2.17 °C。对于降雨对流模式，0.95 ≤ R2≤ 0.96，0.17 °C ≤ RMSE≤0.21 °C，0.15 °C ≤ MAE ≤ 0.2 °C。结果表明：1）在没有降雨的情况下，沥青、水泥、透水砖下垫面的地表温度高于气温，对城市近地表气温有积极影响。此外，温度最低、温差最小的草坪下垫面对城市地表温度有负面影响。2)在降雨过程中，下垫面以对流的形式将热量传递给径流，迫使径流温度升高。沥青对径流的加热作用最明显，草坪对径流温度的影响最小。研究认为，在高温地区可通过铺设草坪降低地表温度，在临近水体的地区可采用透水下垫面，以减少下垫面对径流温度的影响。
With an acceleration of urbanization in China, a large number of natural underlying surface have been replaced by impervious surface, which seriously affect the urban thermal and water environment. In this study, we focus on four typical urban underlying surfaces, asphalt, cement, pervious brick, and lawn. Based on the theory of heat transfer and fluid mechanics, we establish a solar radiation model and a rainfall convection model to analyze the heat transfer process of thermal radiation, thermal conduction, and thermal convection of urban underlying surface under different meteorological conditions. The fitting effects of both models are good: For solar radiation model, 0.89 ≤ R2≤ 0.99, 1.93 °C ≤ RMSE≤2.45 °C, 1.87 °C ≤ MAE ≤ 2.17 °C. For rainfall convection model, 0.95 ≤ R2≤ 0.96, 0.17 °C ≤ RMSE≤0.21 °C, 0.15 °C ≤ MAE ≤ 0.2 °C. Results show that: 1) In the absence of rainfall, the land-surface temperature of asphalt, cement, and pervious brick underlying surface is higher than air temperature, which has a positive effect on urban near-surface air temperature. In addition, the lawn underlying surface with the lowest temperature and the lowest temperature difference has a negative impact on the urban surface temperature. 2) In the rainfall, the underlying surface transfers heat to the runoff in the form of convection, forcing the runoff temperature to rise. Asphalt has the most obvious heating effect on runoff and lawn has the least effect on runoff temperature. The study proposes that the land-surface temperature can be lowered by paving lawn in hot places, and the pervious underlying surface should be adopted in the areas adjacent to the water bodies to reduce the influence of the underlying surface on runoff temperature.