Pumping wells

Pumping wells, under Model Build → Pumping wells, may be either discharge-specified or head-specified. The discharge-specified type may be screened in one domain or across multiple domains if the well screen spans multiple model levels.

Input Common to all Pumping Wells

With all types of pumping wells, the following parameters are required.

• Label is a text label that helps you keep track of multiple wells.
• X,Y defines the horizontal coordinates of the well. Type the coordinates, or click the map pin in the cell and then click the map where you want the well. The map pin is shown when the cell is empty. Clicking a well on the map changes it to a black square, which you can drag to a new location. The coordinates in the table update.
• Radius defines the radius of the well. If there is a high conductivity filter pack around the well screen, the radius should be the radius of the borehole, not the radius of the screen.

Discharge-Specified

With discharge-specified wells, negative rates are used for extraction from the aquifer and positive rates are used for injection into the aquifer. Additional parameters defined here are:

• Domain defines the domain that the well screen is in.
• Discharge is the discharge of the well in units of [L³/T]. In transient simulations, this parameter may vary from one time period to the next.

Discharge-Specified (Multi-Domain)

Use this type of well to simulate a well with a screen that spans multiple domains and levels in the vertical direction. Anaqsim computes the appropriate discharge from each domain spanned so that the total discharge equals the specified discharge, and the heads at the well radius in each domain match each other. With discharge-specified wells, negative rates are used for extraction from the aquifer and positive rates are used for injection into the aquifer.

• Domains defines the domains that the well screen spans.
• Discharge is the discharge of the well in units of [L³/T]. In transient simulations, this parameter may vary from one time period to the next.

Head-Specified

With head-specified wells, you specify a head that applies at the well radius and Anaqsim computes the discharge needed to achieve that head. The discharge of a head-specified well may be checked after solving with the plot results icon on the well row.

• Domain defines the domain that the well screen is in.
• Head at Well defines the head at the well radius. In transient simulations, this parameter may vary from one time period to the next.
• Off Periods sets the well discharge to zero during the listed periods of a transient simulation. Separate multiple period numbers with commas. In the example below, Sump Pump North is off in periods 2 and 3 and uses a specified head of 72 when active.