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Thermal effect of climate change on groundwater-fed ecosystems

Water Resources Research

By:
https://doi.org/10.1002/2016WR020007

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Abstract

Groundwater temperature changes will lag surface temperature changes from a changing climate. Steady state solutions of the heat-transport equations are used to identify key processes that control the long-term thermal response of springs and other groundwater discharge to climate change, in particular changes in (1) groundwater recharge rate and temperature and (2) land-surface temperature transmitted through the vadose zone. Transient solutions are developed to estimate the time required for new thermal signals to arrive at ecosystems. The solution is applied to the volcanic Medicine Lake highlands, California, USA, and associated springs complexes that host groundwater-dependent ecosystems. In this system, upper basin groundwater temperatures are strongly affected only by recharge conditions. However, as the vadose zone thins away from the highlands, changes in the average annual land-surface temperature also influence groundwater temperatures. Transient response to temperature change depends on both the conductive time scale and the rate at which recharge delivers heat. Most of the thermal response of groundwater at high elevations will occur within 20 years of a shift in recharge temperatures, but the large lower elevation springs will respond more slowly, with about half of the conductive response occurring within the first 20 years and about half of the advective response to higher recharge temperatures occurring in approximately 60 years.

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Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Thermal effect of climate change on groundwater-fed ecosystems
Series title:
Water Resources Research
DOI:
10.1002/2016WR020007
Volume:
53
Issue:
4
Year Published:
2017
Language:
English
Publisher:
American Geophysical Union
Contributing office(s):
Forest and Rangeland Ecosystem Science Center, Oregon Water Science Center
Description:
11 p.
First page:
3341
Last page:
3351
Country:
United States
State:
California
Other Geospatial:
Medicine Lake highlands