title: The thermal consequences of river-level variations in an urban groundwater body highly affected by groundwater heat pumps.
abstract: The extensive implementation of ground source heat pumps in urban aquifers is an important issue related to groundwater quality and the future economic feasibility of existent geothermal installations. Although many cities are in the immediate vicinity of large rivers, little is known about the thermal river-groundwater interaction at a kilometric-scale. The aim of this work is to evaluate the thermal impact of river water recharges induced by flood events into an urban alluvial aquifer anthropogenically influenced by geothermal exploitations. The present thermal state of an urban aquifer at a regional scale, including 27 groundwater heat pump installations, has been evaluated. The thermal impacts of these installations in the aquifer together with the thermal impacts from "cold" winter floods have also been spatially and temporally evaluated to ensure better geothermal management of the aquifer. The results showed a variable direct thermal impact from 0 to 6 °C depending on the groundwater-surface water interaction along the river trajectory. The thermal plumes far away from the riverbed also present minor indirect thermal impacts due to hydraulic gradient variations.
authors.affiliation: Department of Earth Sciences, University of Zaragoza, c/Pedro Cerbuna 12, 50009 Zaragoza, Spain; GHS, Institute of Environmental Assessment & Water Research (IDAEA), CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain. Electronic address: agargil@unizar.es.
authors.forename: Alejandro
authors.initials: A
authors.lastname: García-Gil
authors.affiliation: GHS, Institute of Environmental Assessment & Water Research (IDAEA), CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Enric
authors.initials: E
authors.lastname: Vázquez-Suñe
authors.affiliation: Instituto Geológico y Minero de España (IGME), C/Manuel Lasala no. 44, 9° B, 50006 Zaragoza, Spain.
authors.forename: Eduardo Garrido
authors.initials: EG
authors.lastname: Schneider
authors.affiliation: Department of Earth Sciences, University of Zaragoza, c/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
authors.forename: José Ángel
authors.initials: JÁ
authors.lastname: Sánchez-Navarro
authors.affiliation: Department of Earth Sciences, University of Zaragoza, c/Pedro Cerbuna 12, 50009 Zaragoza, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Mateo-Lázaro
mesh_terms: D002947:Cities; D004784:Environmental Monitoring; D055868:Floods; D060587:Groundwater / Q000737:chemistry*; D006358:Hot Temperature; D045483:Rivers / Q000737:chemistry*; D014872:Water Movements
keywords: GSHP; GWHP; Groundwater; River–groundwater interaction; Thermal impact; Thermal management; Urban aquifer