Three-dimensional model simulation of steady-state ground-water flow in the Albuquerque-Belen Basin, New Mexico

Abstract

As part of the Southwest Alluvial Basins study, a three-dimensional groundwater flow model was constructed to simulate the alluvial-aquifer system underlying the Albuquerque-Belen Basin in New Mexico. The model was used to simulate the steady-state flow condition assumed to have existed prior to 1960. Until this time there apparently were no long-term groundwater level changes of a significant magnitude outside the immediate vicinity of Albuquerque. Therefore, the construction of a steady-state flow model of the aquifer system based on reported hydrologic data predating 1960 was justified. During construction of the steady-state model, simulated hydraulic conductivity values were adjusted, within acceptable physical limits, until a best fit between measured or reported and computed heads at 34 control wells was achieved. The modeled area was divided into six subareas, or zones, within each of which hydraulic conductivity was assumed to be uniform. The model consisted of six layers for each of which simulated transmissivity was proportional to the layer thickness. Adjustments to simulated hydraulic conductivity values in the different zones resulted in final values that ranged from a low of 0.25 foot per day in the west to 50 feet per day in the eastern part of the basin. The error of the simulation, defined as the absolute difference between the computed and the measured or reported water level at the corresponding point in the physical system being modeled, ranged from 0.6 foot to 36 feet, with an average of 14.6 feet for the 34 control we 11s .

Estimated 2016 groundwater level and drawdown from predevelopment to 2016 in the Santa Fe Group Aquifer System in the Albuquerque Area, Central New Mexico

“…Although the Santa Fe Group aquifer system throughout the MRGB is generally considered to be unconfined, silt and clay layers within the aquifer can create confined to semiconfined conditions. (Kernodle and Scott, 1986;Bartolino and Cole, 2002). The upper Santa Fe Group is the primary water-bearing unit (Thorn and others, 1993), with some water production yields from the middle and lower units, especially west of the Rio Grande (Bexfield and others, 2011).…”