Thermal management of an unconsolidated shallow urban groundwater body

Abstract

This study presents the development of tools for the sustainable thermal management of a shallow unconsolidated urban groundwater body in the city of Basel (Switzerland). The concept of the investigations is based on (1) a characterization of the present thermal state of the urban groundwater body, and (2) the evaluation of potential mitigation measures for the future thermal management of specific regions within the groundwater body. <br><br> The investigations focus on thermal processes down-gradient of thermal groundwater use, effects of heated buildings in the subsurface as well as the thermal influence of river–groundwater interaction. Investigation methods include (1) short- and long-term data analysis, (2) high-resolution multilevel groundwater temperature monitoring, as well as (3) 3-D numerical groundwater flow and heat transport modeling and scenario development. The combination of these methods allows for the quantifying of the thermal influences on the investigated urban groundwater body, including the influences of thermal groundwater use and heated subsurface constructions. Subsequently, first implications for management strategies are discussed, including minimizing further groundwater temperature increase, targeting "potential natural" groundwater temperatures for specific aquifer regions and exploiting the thermal potential

Groundwater temperature evolution in the subsurface urban heat island of Cologne, Germany

“…Alternatively, a numerical modelling framework may be adopted (Ferguson and Woodbury ; Epting et al . ). Although a numerical model can be more flexible and accurate, this comes at the expense of an enormous data requirement.…”

Groundwater temperature anomalies in central Europe

“…These extreme and until now unregulated heat sources seriously impact our groundwater. When GWTs continue to increase, groundwater cooling systems are no longer efficient [55,69]. Furthermore, high GWT might also affect groundwater quality and ecology (e.g.…”

“…While the AHI of this well is lower than the ones associated with contamination and mining, almost every building in a city has a basement, which typically also hosts the heating installation of the building. Epting and Huggenberger [21], Benz et al [61] and Epting et al [69] also emphasised the large impact of basements on GWT and due to their high heat flux and dominant area, named them as the dominant drivers of SUHIs.…”

Assessment and Minimization of Potential Environmental Impacts of Ground Source Heat Pump (GSHP) Systems

“…Several studies have addressed the numerical modelling of potential interference between adjacent GWHP systems in urban areas [43][44][45][46], but numerical studies with general validity are still lacking. [42]) developed a new indicator called "relaxation factor", which imposes a margin on groundwater temperature alteration, which should be left for future installations, thus providing an alternative to the present approach of "first come, first served".…”

“…An approach called "relaxation factor" was recently proposed [42], which is based on the calculation of the margin for further thermal alteration to be induced by future installations. As the propagation of thermal plumes is a key aspect of the design and management of GSHPs, it has been addressed by several articles on case studies, including the works of [43][44][45][46], and a few theoretical studies, including the works of [47,48].…”