Recharge Package (RCH1)

Please Register

Last modified on Wednesday, January 31, 1996 - 6:27:10 PM

Skip forward to Input instructions for the Recharge Package.

The original instructions for the Recharge Package are on pages 7-6 to 7-7 of McDonald and Harbaugh (1988).

Introduction: The Recharge Package is used to set the rates, timing and location or recharge in model.

Recharge as simulated by the recharge package is independent of head and only occurs in one cell in each vertical column of cells. Recharge to several cells in a vertical column, as might occur in artificial recharge, can be simulated with the Well package. The recharge package also can simulate a steady evapotranspiration rate by specifying a negative recharge rate. The recharge rate has units of length/time.

There are three options for specifying which cell in a vertical column receives recharge.

• Option 1; recharge occurs in the top layer
• Option 2; recharge occurs in specified cells which can be in different layers
• Option 3; recharge occurs in the uppermost active cell in any vertical column

Go back to Contents

Input Instructions

• Line 1
  • Spaces 1-10, NRCHOP, Integer, Recharge option
    • NRCHOP=1, recharge occurs in the top layer
    • NRCHOP=2, recharge occurs in specified cells which can be in different layers
    • NRCHOP=3, recharge occurs in the uppermost active cell in any vertical column
  • Spaces 11-20, IRCHCB, Integer, (You must also set ICBCFL in the Output Control option to print or save cell-by-cell flow terms.)
    • if IRCHCB > 0, IRCHCB is the unit number for cell-by-cell flow terms;
    • if IRCHCB <= 0, cell-by-cell flow terms will not be printed or saved;
• Lines 2+, repeated for every stress period
  • Spaces 1-10, INRECH, Integer
    • If >=0, an array of recharge fluxes RECH(NCOL,NROW) is read
    • If <0, recharge rates for the preceding stress period are reused.
  • Spaces 11-20, INIRCH, Integer, Ignored if NRCHOP = 1 or 3
    • If >=0, an array of layer numbers IRCH(NCOL,NROW) is read
    • If <0, recharge layers for the preceding stress period are used.
• Lines 3+, Used only when INRECH>=0
  • RECH(NCOL,NROW) array entered using U2DREL, Recharge rates, Length/time
• Lines 4+, Used only if NRCHOP=2 and INIRCH>0, repeated for every stress period
  • IRCH(NCOL,NROW) array entered using U2DINT, Recharge Layers

Line 1, Spaces 1-10, Variable = NRCHOP, Integer, Recharge option

• NRCHOP=1, recharge occurs in the top layer.
  Inactive cells including cells which dry out during a simulation will not receive recharge nor will any lower layers.
• NRCHOP=2, recharge occurs in specified cells which can be in different layers.
  Inactive cells including cells which dry out during a simulation will not receive recharge nor will any lower layers.
• NRCHOP=3, recharge occurs in the uppermost active cell in any vertical column.
  No recharge occurs if a constant head cell is the uppermost active cell; the constant head cell intercepts the recharge.

Line 1, Spaces 11-20, Variable = IRCHCB, Integer, cell-by-cell flag and unit number

• if IRCHCB > 0, unit number for cell-by-cell flow terms;
• if IRCHCB <= 0, cell-by-cell flow terms will not be printed or saved;

Lines 2+, Spaces 1-10, Variable = INRECH, Integer

• If >=0, an array of recharge fluxes, RECH(NCOL,NROW), is read as Lines 3+
• If <0, recharge rates for the preceding stress period are used. Lines 3+ are skipped

Lines 2+, Spaces 11-20, Variable = INIRCH, Integer, Ignored if NRCHOP = 1 or 3

• If INIRCH>=0, an array of layer numbers IRCH(NCOL,NROW) is read as Lines 4+
• If INIRCH<0, recharge layers for the preceding stress period are used. Lines 4+ are skipped.

Lines 3+, Array = RECH(NCOL,NROW) entered using U2DREL

Lines 4+, Array = IRCH(NCOL,NROW) entered using U2DINT

Go back to Input instructions for the Recharge Package
Go back to Contents