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User guide for the drawdown-limited, multi-node well (MNW) package for the U.S. Geological Survey's modular three-dimensional finite-difference ground-water flow model, versions MODFLOW-96 and MODFLOW-2000

Keith J. Halford·Randall T. Hanson
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Abstract

A computer program called the drawdown-limited, Multi-Node Well (MNW) Package was developed for the U.S. Geological Survey three-dimensional finite-difference modular ground-water flow model, commonly referred to as MODFLOW. The MNW Package allows MODFLOW users to simulate wells that extend beyond a single model node. Multi-node wells can simulate wells that are completed in multiple aquifers or in a single heterogeneous aquifer, partially penetrating wells, and horizontal wells. Multi-aquifer wells dynamically distribute flow between nodes under pumping, recharging, or unpumped conditions. Variations in intraborehole flow can be simulated with the MNW Package, which is limited by how finely an aquifer system has been discretized vertically. Simulated discharge from single-node and multi-node wells also can be drawdown limited, which is user specified for pumping or recharging conditions. The MNW Package also has the ability to track potential mixes of a water-quality attribute. Simulated wellbore flow can be compared with measured wellbore flow, which provides another constraint for model calibration.

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Keith J. Halford, Randall T. Hanson. 2002. User guide for the drawdown-limited, multi-node well (MNW) package for the U.S. Geological Survey's modular three-dimensional finite-difference ground-water flow model, versions MODFLOW-96 and MODFLOW-2000. https://doi.org/10.3133/ofr02293

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