1. Home
  2. Items
  3. Hydrology and a mathematical model of ground-water flow in the...
PDF

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.

View on Timeline View on Map Download PDF
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:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
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

Contact us about this record

Source
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:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
« Previous Back to Browse Next »