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Hydrology and a mathematical model of ground-water flow in the Pullman-Moscow region, Washington and Idaho Item Info

Increasing pumpage rates and declining ground-water levels in the Columbia River Basalts of the Pullman-Moscow area of Washington and Idaho indicate a need for ground-water management. A three-dimensional numerical computer model of ground-water flow is constructed to guide this management. Basalt aquifer thicknesses of 0 to 3,500 feet are determined by a magnetotelluric geophysical survey in support of the study. The model incorporates a Grande Ronde Basalt layer, a Wanapum Basalt layer, and an overlying surficial loess layer. A recharge rate of 139 cubic feet per second to the upper layer of the ground-water flow model is calculated using a recharge model developed by the U.S. Geological Survey. Ground-water discharge is modeled as stream inflow and seepage where a layer is incised by a river. Cross-sectional models distributed across the domain of the three-dimensional model along flow lines provide an efficient means of obtaining hydraulic coefficient input for the three-dimensional model. The three-dimensional model is calibrated using the time-average method and evaluated through a history match procedure. The model incorporates numerous assumptions and simplifications; model predictions therefore are indicative only of general trends for the future. The model suggests that it is possible for ground-water levels to stabilize if ground-water pumpage stabilizes at a constant level. Ground-water level declines will continue into the foreseeable future as long as ground-water pumpage continues to increase.

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Title:
Hydrology and a mathematical model of ground-water flow in the Pullman-Moscow region, Washington and Idaho
Authors:
Smoot, John Leach; Ralston, Dale R.
Date Created (ISO Standard):
1987-04
Description:
Increasing pumpage rates and declining ground-water levels in the Columbia River Basalts of the Pullman-Moscow area of Washington and Idaho indicate a need for ground-water management. A three-dimensional numerical computer model of ground-water flow is constructed to guide this management. Basalt aquifer thicknesses of 0 to 3,500 feet are determined by a magnetotelluric geophysical survey in support of the study. The model incorporates a Grande Ronde Basalt layer, a Wanapum Basalt layer, and an overlying surficial loess layer. A recharge rate of 139 cubic feet per second to the upper layer of the ground-water flow model is calculated using a recharge model developed by the U.S. Geological Survey. Ground-water discharge is modeled as stream inflow and seepage where a layer is incised by a river. Cross-sectional models distributed across the domain of the three-dimensional model along flow lines provide an efficient means of obtaining hydraulic coefficient input for the three-dimensional model. The three-dimensional model is calibrated using the time-average method and evaluated through a history match procedure. The model incorporates numerous assumptions and simplifications; model predictions therefore are indicative only of general trends for the future. The model suggests that it is possible for ground-water levels to stabilize if ground-water pumpage stabilizes at a constant level. Ground-water level declines will continue into the foreseeable future as long as ground-water pumpage continues to increase.
Subjects:
Groundwater Groundwater development Groundwater basins Confined aquifers Unconfined aquifers Water supply Computer models
Location:
Pullman; Moscow; Northern Idaho
Latitude:
46.74
Longitude:
-117.17
Collection:
Palouse Basin
Series:
Water for Idaho
IWRRI number:
198713
Rights:
In copyright, educational use permitted. Educational use includes non-commercial reproduction of text and images in materials for teaching and research purposes. For other contexts beyond fair use, including digital reproduction, please contact the University of Idaho Library Special Collections and Archives Department at libspec@uidaho.edu. The University of Idaho Library is not liable for any violations of the law by users.
Publisher:
Idaho Water Resources Research Institute; University of Idaho
Contributing Institution:
University of Idaho
Type:
Text
Format:
application/pdf
Cataloger:
KIT
Date Digitized:
2017-09-05

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Preferred Citation:
"Hydrology and a mathematical model of ground-water flow in the Pullman-Moscow region, Washington and Idaho", Idaho Waters Digital Library, University of Idaho Library Digital Collections, https://www.lib.uidaho.edu/digital/iwdl/items/iwdl-198713.html
Rights
Rights:
In copyright, educational use permitted. Educational use includes non-commercial reproduction of text and images in materials for teaching and research purposes. For other contexts beyond fair use, including digital reproduction, please contact the University of Idaho Library Special Collections and Archives Department at libspec@uidaho.edu. The University of Idaho Library is not liable for any violations of the law by users.
Standardized Rights:
http://rightsstatements.org/vocab/InC-EDU/1.0/
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