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SWATmf · USER MANUAL: HOW TO START USING SWATmf ·

Revision 0.1 for SPELLmap v 0.2.2.11 – May 6-2013

JORGE A. GUZMAN

DANIEL N. MORIASI PATRICK J. STARKS

JEAN L. STEINER

ALAN VERSER

ARS - GRAZINGLANDS RESEARCH LABORATORY, EL RENO, OK

EL RENO, OKLAHOMA. MAY 15, 2013

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SWATmf is at development stage and is provided to you by the USDA-ARS Grazinglands Research Laboratory (GRL)

for evaluation purposes as “it is” without any warranty and responsibility. Possession of this software,

documentation, examples or data does not grant permission for commercialization or distribution in any way

without express written permission. SWATmf has not been intensively tested and unexpected results may occur at

any time. Authors and institutions (i.e., USDA, ARS and the GRL) are not responsible for the use, results or data

interpretation derived from using SWATmf, figures or reported data.

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What is SWATmf

SWATmf is a key component in the modeling framework under development at the USDA-ARS

Grazinglands Research Laboratory (GRL) providing comprehensive surface-subsurface modeling

capabilities. SWATmf provide easy integration of the Soil and Water Assessment Tool (SWAT)

and the Newton formulation for the Three-

Dimensional Finite-Difference Groundwater Flow

(MODFLOW) models due to the differences in

their physical discretization and representation.

SWATmf allows setup the SWAT-MODFLOW

model for single surface-subsurface domain or

multiple SWAT surface projects contributing to a

single aquifer system. Moreover, SWATmf serves

to MODFLOW model parameterization and result

visualization. In summary SWATmf is a model project builder.

Functionality of SWATmf is centralized in the opening

form (Figure 2) from which users are allow to select

the MODFLOW packages to be incorporated in the

SWAT-MODFLOW model. The SWAT-MODFLOW

model is a single application integrating or coupling

the SWAT and MODFLOW models. Users must be

aware that the SWAT-MODFLOW model differs from

SWAT and MODFLOW although maintains similar

functionality. In other words, in the SWAT-MODFLOW

model the codes from SWAT and MODFLOW were

combined with additional routines to interact with

SWATmf, and then compiled as a single application. Therefore, is there is bug or improvement

in the SWAT or MODFLOW codes you will find it in the SWAT-MODFLOW model.

1. HOW TO INTEGRATE THE SWAT AND MODFLOW MODELS

In the following tutorial we assume that you have knowledge of the SWAT and MODFLOW

model as well as spatial data representation. To integrate the SWAT and MODFLOW models we

recommend that you proceed to develop the surface and subsurface model independently but

keeping in mind how they are going to interact. Remember, hydrological and water quality

SPELLmapSWATmf

SWAT-MODFLOW

Figure 1. GRL hydrologic modeling framework

Figure 2. SWATmf main form

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models (HWQM) are simplified representation of the real world and how you proceed to

represent that reality will have a great impact in your results. This includes your data (e.g.,

quality assurance) as well as the input-output spatio-temporal scales used, the objective of your

model, and how each model represents processes and mechanism (e.g., model nature).

1.1. SHOPPING LIST FOR USING SWATmf:

1. SWAT projects in a corresponding folder (one per surface watershed; use ArcSWAT to

create this projects)

2. MODFLOW input files needed to build a MODFLOW project (use SPELLmap, a text-

editor and perhaps ArcGIS)

3. The HRU-ID map (You will create this from ArcSWAT)

Fig.4-Convert the HRU GRID to ASCII raster file, MODFLOW format

To create the HRU-ID map you will need to do some GIS operation at the time you create the SWAT

project in ArcSWAT. First, in the ArcSWAT “Land Use/Soil/Slope definition” menu you MUST check the

“Create the HRU Feature Class” option (Figure 3). Be aware that SWATmf and the SWAT-MODFLOW

model do not support the HRU re-classification process. If you find that this is important for your model

you may find a way to refine your input data to avoid this step.

Figure 3. ArcSWAT HRU definition menu

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Figure 4. Table of features class created by ArcSWAT

Second, in ArcGIS select the FullHRU create by ArcSWAT, assign a unique HRUCODE for each HRU using

ArcGIS Editor tool, and then proceed to convert feature to raster with a cell size equal (recommended)

to the input DEM file (in this example 30 x 30 m; use the DEM grid as a mask). Note that you must use

the “HRUcode” field (indicated in cyan color in Figure 4) in this operation (Figure 4 and 5). Finally, you

will need to convert the HRU grid to ASCII raster file as indicated in Figure 6. The ASCII file is what you

will need when using SWATmf to create the SWAT-MODFLOW linking file (automatically created by

SWATmf). You can use any text-editor (we recommend notepad ++ or EditPad Lite for these task) to

browse the map or modify it (you must be familiar with ESRI ASCII grid format).

Figure 5. Feature class to raster conversion in ArcGIS.

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Figure 6. Raster to ASCII conversion in ArcGIS.

To name the HRU-ID map (ASCII file) you can use any name without spaces or special characters and

provide the file extension. We recommend using single and simple names such as “hruID.txt”. Note that

in SWATmf and SPELLmap the following notation is used to separate the data as a function of the file

extension:

1. TXT for space separated (#32)

2. ASC for TAB separated (#9)

3. CSV for comma separated (#44)

After creating the SWAT project, the HRU-ID map, and MODFLOW maps you can proceed to use

SWATmf to build the SWAT-MODFLOW project.

1.2. THE PROJECT WINDOW IN SWATmf:

Before using SWATmf, please verify that you are using the latest version of SPELLmap, SWATmf and the

SWAT-MODFLOW model (uninstall any existing version before install a new one). If you downloaded and

installed SWATmf you must be able to find example data in the following folders:

For windows 64 bits: look for the folders: base, modflowGRIDS and TextInOut in

C:\Program Files (x86)\SWATmf

For windows 32 bits: look for the folders: base, modflowGRIDS and TextInOut in

C:\Program Files\SWATmf

Copy the former folders to an unprotected folder in your hard disk (e.g., c:\swatmf). Note

that the C:\Program Files (x86) folder is protected and SWATmf will crash if executed.

In the folder you placed the data create a new folder with the name SWATmf-1

Run SWATmf and select project/new

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Figure 7. SWATmf project window

In the window PROJECT we will setup a SWAT-MODFLOW project consisting of one surface watershed

matching one aquifer system:

1. Type the number one and hit ENTER

2. Double click the first row, browse for the folder swatmf-1 (previously created) in

c:\swatmf, and then click in SELECT FOLDER

3. Leave the MODFLOW name file as it is (i.e., SWATmf)

4. This button must be green and inactivated (on SWAT-MODFLOW projects with one

surface SWAT model, the master MODFLOW project will be created in the folder

defined in step 2

5. Click the red button, browse for the folder c:\swatmf\modflowgrids, and then click in

SELECT FOLDER.

At this moment your window PROJECT must exhibit a different view and the blac area in Figure 7

must be active

6. Click the red button, browse for the file mfEXTENT.txt, then click OPEN (located in

c:\swatmf\modflowgrids).

7. Leave the number of layers as one

Type here the number of surface

project s you will use, then hit ENTER

Type here the name of the MODFLOW

project you will use

After you enter the number of SWAT projects equal number of rows will

appear in this box. Double click in each row to define the folder in which each

SWAT-MODFLOW project will be created

Click here to select the folder where the master MODFLOW

project will be located

Click here to select the folder where the

MODFLOW data necessary to build

the MODFLOW project is located

Click here to select the GRID file that

define the MODFLOW extent

Type here the number of layers that define your

MODFLOW project

1

2

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5

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8. Double click the first row, browse for the file “file.cio” in c:\swatmf\TxInOut\, and then

click OPEN

9. Double click the first row, browse for the file “hru240m1.txt” in

c:\swatmf\modflowGRIDS\, and then click OPEN

10. Click the ACCEPT button to return to the main menu (Figure 2).

Figure 8. SWATmf project window

Double click on the row to select SWAT

*.cio for the corresponding

project

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Double click on the row to select HRU-

ID map for the corresponding

project

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