Karlsruhe Institute of Technology (KIT) , Institute for Applied Geosciences (AGW), Kaiserstrasse 12, 76131 Karlsruhe, Germany.
Environ Sci Technol. 2013 Sep 3;47(17):9747-55. doi: 10.1021/es401546u. Epub 2013 Aug 19.
Anthropogenic alterations in urban areas influence the thermal environment causing elevated atmospheric and subsurface temperatures. The subsurface urban heat island effect is observed in several cities. Often shallow urban aquifers exist with thermal anomalies that spread laterally and vertically, resulting in the long-term accumulation of heat. In this study, we develop an analytical heat flux model to investigate possible drivers such as increased ground surface temperatures (GSTs) at artificial surfaces and heat losses from basements of buildings, sewage systems, subsurface district heating networks, and reinjection of thermal wastewater. By modeling the anthropogenic heat flux into the subsurface of the city of Karlsruhe, Germany, in 1977 and 2011, we evaluate long-term trends in the heat flux processes. It revealed that elevated GST and heat loss from basements are dominant factors in the heat anomalies. The average total urban heat flux into the shallow aquifer in Karlsruhe was found to be ∼759 ± 89 mW/m(2) in 1977 and 828 ± 143 mW/m(2) in 2011, which represents an annual energy gain of around 1.0 × 10(15) J. However, the amount of thermal energy originating from the individual heat flux processes has changed significantly over the past three decades.
人为因素改变了城市地区，影响了热环境，导致大气和地下温度升高。在许多城市都可以观察到地下城市热岛效应。通常存在具有热异常的浅层城市含水层，这些异常会横向和纵向扩散，导致热量长期积累。在这项研究中，我们开发了一个分析热通量模型，以研究可能的驱动因素，如人工表面的地面温度（GST）升高和建筑物地下室、污水系统、地下区域供热网络以及热废水再注入的热量损失。通过对德国卡尔斯鲁厄市 1977 年和 2011 年地下人为热通量进行建模，我们评估了热通量过程的长期趋势。结果表明，升高的 GST 和地下室的热量损失是热异常的主要因素。研究发现，1977 年和 2011 年，卡尔斯鲁厄浅层含水层的平均总城市热通量分别约为 759±89 mW/m(2)和 828±143 mW/m(2)，这代表每年约 1.0×10(15) J 的能量增益。然而，过去三十年来，源自各个热通量过程的热能数量发生了显著变化。
