title: Forecasting Groundwater Temperature with Linear Regression Models Using Historical Data.
abstract: Although temperature is an important determinant of many biogeochemical processes in groundwater, very few studies have attempted to forecast the response of groundwater temperature to future climate warming. Using a composite linear regression model based on the lagged relationship between historical groundwater and regional air temperature data, empirical forecasts were made of groundwater temperature in several aquifers in Switzerland up to the end of the current century. The model was fed with regional air temperature projections calculated for greenhouse-gas emissions scenarios A2, A1B, and RCP3PD. Model evaluation revealed that the approach taken is adequate only when the data used to calibrate the models are sufficiently long and contain sufficient variability. These conditions were satisfied for three aquifers, all fed by riverbank infiltration. The forecasts suggest that with respect to the reference period 1980 to 2009, groundwater temperature in these aquifers will most likely increase by 1.1 to 3.8 K by the end of the current century, depending on the greenhouse-gas emissions scenario employed.
authors.affiliation: ETH Zurich, Institute of Biogeochemistry and Pollutant Dynamics, Universitätsstrasse 16, CH-8092, Zürich, Switzerland.|Eawag: Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600, Dübendorf, Switzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Figura
authors.affiliation: Eawag: Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600, Dübendorf, Switzerland.
authors.forename: David M
authors.initials: DM
authors.lastname: Livingstone
authors.affiliation: ETH Zurich, Institute of Biogeochemistry and Pollutant Dynamics, Universitätsstrasse 16, CH-8092, Zürich, Switzerland.|Eawag: Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, CH-8600, Dübendorf, Switzerland.|ETH Zurich, Institute of Geochemistry and Petrology, Clausiusstrasse 25, CH-8092, Zürich, Switzerland.
authors.forename: Rolf
authors.initials: R
authors.lastname: Kipfer
mesh_terms: D057231:Climate Change; D005544:Forecasting; D060587:Groundwater; D016014:Linear Models; D013557:Switzerland; D013696:Temperature