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HYD - HYDMOD Package

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HYD - HYDMOD Package

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HYD - HYDMOD Package

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Abbreviation in Name file

HYD

Purpose

The HYDMOD package is used to record time-series data for selected data types.

Documentation

Hanson, R.T., and Leake, S.A., 1999, Documentation for HYDMOD, a program for extracting and processing time-series data from the U.S. Geological Survey's modular three-dimensional finite-difference ground-water flow model: U.S. Geological Survey Open-File Report 98-564, 57 p.

Hydmod7.pdf

Supported in

MODFLOW-2000
MODFLOW-2005
MODFLOW-LGR
MODFLOW-CFP
MODFLOW-NWT
MODFLOW-OWHM

Input Instructions

Input to the HYDMOD package is read from the file name and unit specified in name file for MODFLOW-2000. The file type that is added to the name file for HYDMOD is specified as HYD.

FOR EACH SIMULATION

Data Set 1

NHYD IHYDUN HYDNOH (free format)

NHYD is the maximum number of observation points that may be read in.

IHYDUN is a unit number to which hydrograph records are written.

HYDNOH is a user-specified value that is output if a value cannot be computed at a hydrograph location. For example, the cell in which the hydrograph is located may be a no-flow cell.

Data Set 2

PCKG ARR INTYP KLAY XL YL HYDLBL (free format)

(Input item 2 consists of one record for each hydrograph. No more than NHYD hydrograph records will be read.)

PCKG is a 3-character flag to indicate which package is to be addressed by HYDMOD for the hydrograph of each observation point. The current packages are:

BAS for the Basic Package,
IBS for the Interbed-Storage Package,
SUB for the Subsidence Package,
STR for the Streamflow Routing Package, and
SFR for the SFR2 Streamflow Routing Package.

ARR is a text code indicating which model data value is to be accessed for the hydrograph of each observation point. The table of available values:

ARR

Value Feature to be recorded by HYDMOD

HD

Head  (BAS package)

DD

Drawdown  (BAS package)

HC

Preconsolidation-head (SUB and IBS1 packages)

CP

Instantaneous compaction (SUB and IBS1 packages)

SB

Instantaneous subsidence array (SUB and IBS1 packages)

ST

Stream stage (SFR and STR packages)

SI

Streamflow into reach array (SFR and STR packages)

SO

Streamflow out of reach (SFR and STR packages)

SA

Streamflow into or out of aquifer array (SFR and STR packages)

INTYP is a 1-character value to indicate how the data from the specified feature are to be accessed. The two options are I for interpolated value or C for cell value. Interpolated value indicates that the value is linearly interpolated from values at the 4 nodes surrounding the hydrograph location. Cell value means the value at the node closest to the hydrograph location. INTYP must be C for STR and SFR hydrographs.

KLAY is the layer sequence number of the array to be addressed by HYDMOD. For arrays that exist for each model layer, such as head (HNEW), KLAY is the layer number. For arrays that exist for only certain model layers, KLAY is the sequence number of the array starting with the uppermost array as 1, the next lower array as 2, and so forth. For the subsidence option (ARR = ‘SB’), KLAY designates the range of layers (from layer 1 to layer "KLAY") used to sum compaction from individual layers into total subsidence for these layers.

XL is the coordinate of the hydrograph point in model units of length measured parallel to model rows, with the origin at the lower left corner of the model grid (fig. 2). The value of XL does not need to correspond with the location of any particular model node. For streamflow-related data, XL designates the segment number that contains the reach from the streamflow-input data set for which data are to be output.

hydmod2

Figure 2. Diagram showing test problem layout and coordinates used for interpolation.

YL is the coordinate of the hydrograph point in model units of length measured parallel to model columns, with the origin at the lower left corner of the model grid (fig. 2). The value of YL does not need to correspond with the location of any particular model node. For streamflow-related data, YL designates the reach number that is the cell location from the streamflow-input data set for which data are to be output.

hydmod2

Figure 2. Diagram showing test problem layout and coordinates used for interpolation.

HYDLBL is used to form a label for the hydrograph. The purpose of the label is to identify output and allow users to reorder, add, or subtract from the input list and still maintain location identity. HYDLBL is up to 14 characters for the BAS, IBS, and SUB Packages. An additional 6 characters are added as a prefix to make a 20-character label. The first two characters of the prefix are the ARR characters. The third character is the INTYP value. Characters 4 through 6 are the KLAY value. For stream hydrographs, HYDLBL is up to 12 characters. The constructed prefix consists of the 2-character ARR value, the 3-digit stream-segment number (character locations 3 to 5), and the 3-digit stream-reach number (character locations 6 to 8). The prefix is added to HYDLBL to again make a 20-character hydrograph label.