A municipal wellfield consists of five water supply wells, each rated at 16 L/s. The wells are located 100 m apart along a north-south line and fully penetrate a 20-m thick confined aquifer that has a transmissivity of 1000 m2/day and a storage coefficient of 6 x 10-5. Estimate the drawdown 500 m west of the center well after one week, one month, one year, and one decade of wellfield operation.
Solve the problem using MAGNET and an analytical approach. Compare the results.
MAGNET/Modeling Hints:
- Use ‘Synthetic mode’ in MAGNET to create a model domain.
- Use the ‘Distance Display’ capabilities when editing geometric features and/or the ‘Ruler’ tool to properly represent distances between model features.
- Assume
the initial head is zero and spatially-constant. (‘Initial’ refers to the
instant the wells are installed but has not yet started pumping).
- Make
sure the ‘no-flow’ side boundaries are sufficiently far away so that they are
outside the area of influence under maximum pumping conditions.
- Use
a large number of grid cells (e.g., NX=100) in your model.