Evaluating mountain meadow groundwater response to Pinyon-Juniper and temperature in a great basin watershed

Ecohydrology
By: , and 

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Abstract

This research highlights development and application of an integrated hydrologic model (GSFLOW) to a semiarid, snow-dominated watershed in the Great Basin to evaluate Pinyon-Juniper (PJ) and temperature controls on mountain meadow shallow groundwater. The work used Google Earth Engine Landsat satellite and gridded climate archives for model evaluation. Model simulations across three decades indicated that the watershed operates on a threshold response to precipitation (P) >400 mm/y to produce a positive yield (P-ET; 9%) resulting in stream discharge and a rebound in meadow groundwater levels during these wetter years. Observed and simulated meadow groundwater response to large P correlates with above average predicted soil moisture and with a normalized difference vegetation index threshold value >0.3. A return to assumed pre-expansion PJ conditions or an increase in temperature to mid-21st century shifts yielded by only ±1% during the multi-decade simulation period; but changes of approximately ±4% occurred during wet years. Changes in annual yield were largely dampened by the spatial and temporal redistribution of evapotranspiration across the watershed: Yet the influence of this redistribution and vegetation structural controls on snowmelt altered recharge to control water table depth in the meadow. Even a small-scale removal of PJ (0.5 km2) proximal to the meadow will promote a stable, shallow groundwater system resilient to droughts, while modest increases in temperature will produce a meadow susceptible to declining water levels and a community structure likely to move toward dry and degraded conditions.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Evaluating mountain meadow groundwater response to Pinyon-Juniper and temperature in a great basin watershed
Series title Ecohydrology
DOI 10.1002/eco.1792
Volume 10
Issue 1
Year Published 2017
Language English
Publisher Wiley
Contributing office(s) National Research Program - Western Branch
Description e1792; 18 p.
First page 1
Last page 18
Country United States
State Nevada
Other Geospatial Great Basin
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