Data wellid qdes capmult cprime xyz wellid must

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Unformatted text preview: ed by the pump manufacturer. These data provide intermediate values for a lookup table in which the end (limiting) values are derived from values specified earlier in dataset 2g. Appendix 1—Data Input Instructions for Multi-Node Well (MNW2) Package 51 FOR EACH STRESS PERIOD: 3. Data: ITMP ITMP is an integer value for reusing or reading multi-node well data; it can change each stress period. ITMP must be ≥ 0 for the first stress period of a simulation. • if ITMP > 0, then ITMP is the total number of active multi-node wells simulated during the stress period, and only wells listed in dataset 4a will be active during the stress period. Characteristics of each well are defined in datasets 2 and 4. • if ITMP = 0, then no multi-node wells are active for the stress period and the following dataset is skipped. • if ITMP < 0, then the same number of wells and well information will be reused from the previous stress period and dataset 4 is skipped. IF ITMP > 0: For each multi-node well (that is, repeat dataset 4 ITMP times): 4a. Data: WELLID Qdes {CapMult} {Cprime} {xyz} WELLID must correspond with one of the names defined in dataset 2a. Including WELLID in this dataset means it will be an active well during this stress period. Qdes CapMult Cprime [xyz] is the actual (or maximum desired, if constraints are to be applied) volumetric pumping rate (negative for withdrawal or positive for injection) at the well (L3/T). Qdes should be set to 0 for nonpumping wells. If constraints are applied, then the calculated volumetric withdrawal or injection rate may be adjusted to range from 0 to Qdes and is not allowed to switch directions between withdrawal and injection conditions during any stress period. When PUMPCAP > 0, in the first stress period in which Qdes is specified with a negative value, Qdes represents the maximum operating discharge for the pump; in subsequent stress periods, any different negative values of Qdes are ignored, although values are subject to adjustment for CapMult. If Qdes ≥ 0.0, then pump-capacity adjustments are not applied. is a flag and multiplier for implementing head-capacity relations during a given stress period. Only specify if PUMPCAP > 0 for this well. If CapMult ≤ 0, then head-capacity relations are ignored for this stress period. If CapMult = 1.0, then head-capacity relations defined in datasets 2g and 2h are used. If CapMult equals any other positive value (for example, 0.6 or 1.1), then head-capacity relations are used but adjusted and shifted by multiplying the discharge value indicated by the head-capacity curve by the value of CapMult. is the concentration in the injected fluid. Only specify if Qdes > 0 and GWT process is active. represents a list of up to five auxiliary variables for a multi-node well that have been defined in dataset 1. The auxiliary variables must be present in each repetition of dataset 4a if they are defined in dataset 1. If Qlimit < 0: 4b. Data: Hlim QCUT {Qfrcmn Qfrcmx} Hlim is the limiting water level (head) in the well, which is a minimum for discharging wells and a maximum for injection wells. For example, in a discharging well, when hWELL falls below hlim, the flow from the well is constrained. QCUT is an integer flag that indicates how pumping limits Qfrcmn and Qfrcmx will be specified. If pumping limits are to be specified as a rate (L3/T), then set QCUT > 0; if pumping limits are 52 Revised Multi-Node Well (MNW2) Package for MODFLOW Ground-Water Flow Model Qfrcmn Qfrcmx to be specified as a fraction of the specified pumping rate (Qdes), then set QCUT < 0. If there is not a minimum pumping rate below which the pump becomes inactive, then set QCUT = 0. is the minimum pumping rate or fraction of original pumping rate (a choice that depends on QCUT) that a well must exceed to remain active during a stress period. The absolute value of Qfrcmn must be less than the absolute value of Qfrcmx (defined next). Only specify if QCUT ≠ 0. is the minimum pumping rate or fraction of original pumping rate that must be exceeded to reactivate a well that had been shut off based on Qfrcmn during a stress period. The absolute value of Qfrcmx must be greater than the absolute value of Qfrcmn. Only specify if QCUT ≠ 0. Note 10: Only specify dataset 4b if the value of Qlimit associated with the well defined by WELLID in dataset 4a is negative (where Qlimit is defined in dataset 2b). Do not enter fractions as percentages. For example, if QCUT < 0, and the well must exceed 80 percent of the original pumping rate to remain active, then enter a value of “0.8” for Qfrcmn. If QCUT > 0, then the rates specified for Qfrcmn and Qfrcmx follow the sign convention for MODFLOW; that is, for discharging wells the rate should be negative, and for recharging (injection) wells the rate should be positive. Multi-Node Well Information (MNWI) Package Data calculated for multi-node wells can be recorded at every time increment using the MNWI Package. The specific nature of the recorded and wr...
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