Table of Contents

Goals of the Exercise
Computer and Data Requirements
Watershed Delineation Tutorial
NPSM Tutorial
Getting Started
Watershed Delineation
Using NPSM
Appendix

This exercise is structured after the EPA BASINS Training Workshop for BASINS2 training.

This exercise will familiarize the user with the tools available in BASINS. The first two parts of the exercise use the tutorial included with the BASINS CD-ROM. The tutorial shows how the delineation tool and NPSM model works. The following exercise will walk you through the delineation of Onion Creek in Texas. The final exercise will run the NPSM model on the Onion Creek Watershed. For your reference, Onion Creek is a tributary of the Colorado River which is located in the south end of Austin, TX. The objective of the model is to determine the overland flow and fecal coliform contributions to Onion Creek from the watershed. The general goals of using the NPSM model is to perform hydrologic and water quality simulations.

Computer and Data Requirements

 ArcView 3.0a and BASINS2 software are needed for the exercise. The BASINS2 software can be downloaded from the EPA Internet Site: http://www.epa.gov/OST/BASINS/.  In addition, you should download the Texas data files, the tutorial files, and the User's Manual.  The User's Manual will walk you through the installation of the files.  In addition, there are download instructions on the webpage.

The computer requirements needed to run the BASINS software are listed below:
Computer Pentium w/ CD-ROM
RAM 32 MB
Free disk space 400 MB for an average State
Operating System Windows 95
GIS software ArcView 3.0a

We recommend that you do not attempt to run this exercise on a machine that is running Windows NT - as of mid May 1998, the BASINS2 software still had some bugs associated with Windows NT that needed to be worked out.
 

 Watershed Delineation Tutorial

Using the Windows Start button, click on the Programs icon which will lead you to the Windows NT Explorer program. Click on the Windows NT Explorer icon. Click on the C: drive icon. Click on the Basins folder. Click on the Tutorial folder. Click on the Tutor icon. Click on the Delineate a Watershed button. Watch the show. Click on the Exit button when you are finished unless you are going directly on to the NPSM tutorial. In that case, go directly to the ** in the next section.

NPSM Tutorial

Using the Windows Start button, click on the Programs icon which will lead you to the Windows NT Explorer program. Click on the Windows NT Explorer icon. Click on the C: drive icon. Click on the Basins folder. Click on the Tutorial folder. Click on the Tutor icon. **Click on the Run NPSM Model button. Watch the show. Click on the Exit button when you are finished.

Getting Started

Using the Windows Start button, click on the Programs icon which will lead you to the Basins program. Click on the Basins icon. Open the project called texas.apr.

In order to get the texas.apr project, a data extraction must be done along with the build program. These two process are explained in the BASINS users manual. They are not discussed in this exercise due the time involved.

** Immediately save the project to a directory of your own with a unique name.**

The BASINS program saves to its own folder as the default.  If others have access to the machine that you are working on they may have access to your files which are created while you work.  You will not have the option to save most of your data files else where, but you will have the option to save your project to where you want it. This will partially secure your project as you own.  The reason for this is because this version of BASINS2 is still in Beta format and some of the bugs have not been worked out.
 

Watershed Delineation

The major steps required for watershed delineation consist of the following:

• Select the cataloging unit in which delineation will be performed
• Declare a watershed name
• Create the outline for the watershed using the cursor and a point-and-click routine.

1. Activate the Basins View.
2. Display and activate the Cataloging Unit Boundary theme by clicking the box and the name of the theme.
3. Use the query builder in the Theme menu to locate Cataloging Unit (CU) # 12090205. Zoom to the selected features using this button .
4. Unselect the Cataloging Unit once it has been located by using the "Clear Selected Feature" tool .
5. Display and activate the Reach File, V1 theme.
6. Use the query builder to locate Onion Creek (Pname is the field). Zoom in closer to the selected features while making sure you can still see part of the east and west boundaries of the CU.
7. Unselect Onion Creek (use the "Clear Selected Feature" tool again).
8. Select CU # 12090205 by activating the theme and using the Select Feature tool (The watershed delineation will be performed within this cataloging unit’s boundaries).
9. Depress the watershed delineation button (denoted by a "W") to create a name for the watershed being delineated.
10. Use yourname.shp as the name. Remember to save it in a directory of your own.

NOTE: your soon-to-be created watershed name is listed at the top of the themes list. Also, a dashed box appears around the checked box next to the new watershed’s theme name. This dashed box notifies you that your watershed is in "editing" mode. To create the watershed outline, the watershed must be in "editing" mode. If you are not in "editing" mode, simply depress "W" again.
 

11. Begin to create the outline for the watershed at CU # 12090250's boundary by clicking the mouse.  Best results are produced by an "out-and-back" procedure, i.e. delineate in the direction of the tributary’s mouth (on one side of the tributary) and return to the CU boundary (on the other side of the tributary).  Be sure to click at a point just outside of the CU boundary.  I recommend using the west, east and southern boundaries of the CU and only artificially creating the north boundary of the new watershed.  Another point of interest is to try not to include any of the Colorado River in the watershed you are delineating. This will cause problems when trying to run the NPSM module.
12. Complete one segment of the outline by moving the cursor, drawing a segment, and clicking the mouse a second time.
13. Repeat this point-and-click process until the entire watershed outline is developed.
14. Finish the watershed outline at the same CU boundary you started from by double-clicking the mouse outside of the CU.  If you have trouble with this part, you can delete the yourname.shp theme from the view (using Edit/Delete Theme) and also delete it from the directory where you had saved it and start the process over.
15. Once the watershed has been delineated successfully, it is represented by a visible outline.
16. When prompted to continue subwatershed delineation, select NO. YES would be selected if multiple subwatersheds were to be delineated.

 NOTE: It is likely that the watershed outline you delineated does not follow the actual boundary of the watershed too well. As a consequence, it may be necessary to clean the initial delineation. Be sure the yourname.shp theme is active, and click on the BASINS cleaning tool (denoted by a "C"). Create a box enclosing a segment of the delineated watershed’s outline. Click YES to delete the line. Once the line has been deleted, the previously-delineated watershed disappears. When prompted to continue cleaning, click NO. Re-delineate the watershed as described in previous steps. When you are prompted to export watersheds, select NO. This saves your new delineation to the .shp file already created for your watershed (yourname.shp). Selecting YES would enable you to create an additional .shp file for the re-delineated watershed (under a different name).

Your delineated watershed should look something like this:

Answer the following questions:

1. Turn in a picture of the watershed you delineated.
2. What is the name of the closest weather station? (Use the identify tool)_____________

(Be sure to take note of its name, as it will be used for NPSM modeling.)

3. What is the total area of the watershed?(Use the identify tool - area is m²)?________
4. What are the types of land uses found in the watershed?_______________

Using NPSM

 
The following steps are performed within the NPSM interface and are required for an NPSM simulation:

• Load watershed and reach data. (Landuse, reach, and point source data for the watershed must be loaded into the NPSM interface to perform a simulation.)
• Edit reach information. (Missing reach data imported from BASINS must be updated.)
• Assign meteorological data to the watershed and select a simulation period. (A WDM file containing meteorological time series data for multiple weather stations must be selected. Weather station(s) must be assigned for each watershed being modeled. A simulation period needs to be designated. This period must fall within the time period of data contained in the WDM file.)
• Edit landuse data. (Landuses have already been divided into PERLNDs and IMPLNDs based on the previously assigned. Percent perviousness (PERLND and IMPLND) areas can be changed if necessary.)
• Select NPSM modules. (NPSM modules must be selected for the simulation. These modules simulate separate processes, for example: overland hydrology (PWATER for pervious land units and IWATER for impervious land units), flow routing (HYDR), sediment processes (SEDMNT for pervious land units, SOLIDS for impervious land units, and SEDTRN for sediment transport in reaches).
• Select pollutants to model. (Once NPSM modules required for simulating quality processes have been designated, it is necessary to select pollutants to simulate.)
• Edit point source data. (Point source data imported from BASINS can be edited. Additional point sources can be added and existing point sources can be removed.)
• Load a default data set (Parameter values for landuses, reaches, and pollutants are saved in a default data set. Selection of a default file is required. Once the file containing parameter values is selected, the data must be loaded. That is, appropriate parameter values for PERLND and IMPLND landuses, reaches, and pollutants in the default data set must be assigned to those being modeled.)
• Edit NPSM parameters. (Parameter values loaded from a default set can be edited for the simulation being performed. Parameters not included in the default set can also be assigned values. This step is important for model calibration.)
• Run the model and view output.

1. Activate the Basins View.
2. Activate the watershed theme that you created and select it using the Select Feature tool .
3. Run NPSM from the MODEL menu and save the model run as yourproj. This will create a directory in c:\basins\modelout in which all of the modeled output will be saved.  A window will pop up indicating the ID number selected - it should be 1209025036.
4. When prompted to View/Modify the default % perviousness, select YES. These values will be applied to the watershed being modeled.
5. Change the percent pervious value to 100% pervious for the Unclassified landuse from 0%.
6. Select 1993 as the discharge year for point source loading.

Note - You may get a warning message stating that No PCS Data was found.  There are a few PCS points within the watershed that you created, but for some reason, they are not picked up.  Just click OK.

1. Look at the BASINS views produced while preparing the data for the NPSM model. This appears an instant before the NPSM interface appears. You will have to make the BASINS interface active to view the output.
2. Once the NPSM interface screen appears, create a new project by selecting the button on the far left side of the toolbar .
3. Choose the yourname.wsd file, in order to load data for the selected watershed into your new project.
4. When the "Trapezoidal Import Data Review" window appears, change the slope value from -9999.0000 to 0.0018 (be sure to press the enter key after typing in this value).

 Discussion of this information will follow in an appendix.

Note - At this point you will probably get a message stating "Unable to open GIS point source input file" with a pathname looking for a .psr file.  This error message is a result of the fact that No PCS Data was found earlier.  Just click OK and continue.
 

5. Select the REACH EDITOR button (denoted by a stream network ), and select the REACH CHARACTERISTICS button from the list of selections.
6. Check to make sure there are no -9999.00 00 values in any of the fields. Use your engineering judgment to change the values, if needed.

 Again, discussion of information in these tables will follow in an appendix.

7. Click OK and then DONE when finished editing the reach information.
8. Select the SIMULATION TIME button .
9. Select the reg06.wdm file containing meteorological data for the state of Texas by depressing the browse button, denoted by "…".
10. Enter a simulation time period of 01/01/1980 (00) - 12/31/1983 (24).
11. Assign the weather station closest to Onion Creek to the watershed being modeled using the pulldown menu.
12. In the Unselected Watershed Box, double click on Onion Cr to select it.
13. Click OK.
14. Select the LANDUSE EDITOR button .

NOTE: The table lists all PERLND and IMPLND segments and their respective areas, as they will be represented by the model. Values in this table were transferred directly from the watershed delineated for Onion Creek.

NOTE 2: Changes can be made to landuse areas if necessary. Click OK when finished.

15. Select the NPSM CONTROL CARDS button . This section displays the names of all NPSM modules.
16. Activate the ATMP, PWATER, and PQUAL modules for Pervious land.
17. For Impervious land segments, select ATMP, IWATER and IQUAL.
18. Also select the HYDR, ADCALC, and GQUAL modules for the Reaches.

NOTE: These modules are necessary for performing hydrologic and water quality functions.

19. Click OK and Close when finished.
20. Then depress the POLLUTANT SELECTION button, , and select "Fecal Coliform, #/100ml" from the pollutant list as the pollutant for water quality simulation.  This can be accomplished by going to the Pollutant List, highlighting the pollutant Fecal Coliform, #/100ml, and clicking the Left Arrow button. Click OK.
21. Since there are no point sources in the watershed (we noted earlier that no PCS Data was found), the point source button, , will not be needed.
22. Depress the DEFAULT DATA ASSIGNMENT button .
23. Browse for available default files by clicking on the "…" button, and choose the initial.def default data file.
24. Depress the LOAD ALL button to load all data available in the default file into your present simulation.

NOTE: This action essentially checks to see if any default data for landuses in your watershed are contained in the default data set (by comparing landuse names). If any data exists in the default file for your landuse types, it is automatically assigned to your landuses. If any landuses are not assigned data from the default file (i.e. if data for a particular landuse is not available in the default data set), a warning will appear. In this situation, it is necessary to manually assign data from a similar landuse or reach (in the default set) to the landuse or reach being modeled. Use the Right Arrow button to perform this function. A problem I found with the initial.def is that there is no data for pollutants other than nitrate, ammonium and fecal coliforms.

NOTE 2: Reach information from the default data set is automatically assigned to reaches being modeled. This is independent of the reach name.
 

25. Assign the Pasture Land default data to the unassigned landuse by highlighting Pasture Land in the "Available Data" list and highlighting Range Land in the "Actual Land Unit" list.
26. Then click the ASSIGN TO arrow button.

NOTE: Rangeland then appears in the "Assigned Land Units" list with the automatically-assigned landuses (Forest Land, Agricultural Land, and Urban Land).

NOTE2: The manual assigning you just performed was only for the pervious land units, because the "Pervious Land" radial button is selected. Also select the "Impervious Land" and "Reach" radial buttons to be sure default data has been assigned for all impervious land units and reaches.
 

27. Also, depress the POLLUTANT ASSIGNMENT button and be sure that Fecal Coliform has been assigned default values.
28. Click CLOSE when you are done.
29. Select the INPUT DATA EDITOR button (denoted by a calculator ).
30. PERLND, IMPLND, and RCHRES module names are initially visible.

READ APPENDIX!! The data groups and their sub-groups are set up in a tree-like structure. Double-clicking on a module name results in the listing of data groups within the module. Double-clicking on a data group name results in the listing of additional data groups within the chosen data group, or a listing of parameters associated with the data group. Actual parameter names will not have  a "+" or "-" symbol in front of them.  If you double click on a parameter name, a screeen will pop up that will allow you to edit that parameter.  Explanation of some of the parameters are located in the appendix.

31. Depress the "Run" button, , to run the model. You will be prompted to save the file. Save the project as yourname.prj.
32. Choose to View Output after running the simulation. The View Output option is divided into separate sections for:
PERLND
IMPLND
RCHRES
33. First, view the flow contribution from the Agricultural Landuse.
34. Do so by highlighting it in the section listing "Pervious Lands" and select VIEW.

Pervious cover:

Impervious Cover:

Reach Output:

 Answer the following question:

1. What was the selected watershed ID #?_________________
2. What was the default % perviousness for Urban or Built-up Land?__________
3. For what time span was meteorological data available in the reg06.wdm file?_______
4. Which landuse accounts for the largest area in the watershed?_________
5. What is the total area of the watershed?____________________
6. How does this compare to the watershed area found while in the GIS portion of BASINS?___________________
7. What landuse is not accounted for in the default data set?______________

In the Input Data Editor Section:

8. What modules are selected for the IMPLND section?_____________
9. Do these modules match the ones selected in the NPSM Control Cards section?____

NOTE: You must exit the Input Data Editor window and return to the NPSM Control Cards window to perform this action.
 

10. How many parameters are associated with the PWAT-PARM3 data sub-group, within the PWATER data group of the PERLND module?
11. Is the interception storage capacity for PERLND represented by a constant or monthly varying values? _____________

Hint: the -PARM1 section of each data group generally offers the user the opportunity to change parameters from constant to monthly.
 

12. Is the interflow inflow parameter represented by constant or monthly varying values?______________
13. What are the units for each of these cloumns of output?___________

NOTE: The beginning of this text file lists information about the data. (Recall that the pollutant is fecal coliform bacteria).
 

14. What is the fecal coliform loading contribution from the Agricultural landuse on May 13, 1983?___________________
15. How does this compare to each of the other pervious landuse fecal coliform loading values for the same day?(List their values)________________________

APPENDIX

This appendix contains some description of some of the default data parameters.  For more detailed information, we suggest that you download the EPA Users Manual.  Data groups and their associated parameters are listed.  Parameters which need special attention during either initial simulations of a watershed or during calibration are in bold text.

PERLND Default Data
 
NOTE: The active modules of PERLND segments for hydrologic and general water quality simulation are:

• ATMP
• PWATER
• PQUAL

ATEMP-DAT - Temperature information

• ELDAT - varies for different geographic locations, and must be addressed whenever the model is run on a new watershed.
• AIRTMP - varies for different geographic locations, and must be addressed whenever the model is run on a new watershed.

 PWAT-PARM2 - Surface and subsurface characteristics

• FOREST
• LZSN - varies based on soil characteristics, calibration parameter
• INFILT - varies based on soil characteristics, calibration parameter
• LSUR - varies for different watersheds, calibration parameter
• SLSUR - varies for different geographic locations
• KVARY
• AGWRC

• PETMAX
• PETMIN
• INFEXP
• INFILD
• DEEPFR - varies based on subsurface characteristics, calibration parameter
• BASETP
• AGWETP

• CEPSC - dependent upon land cover, calibration parameter
• UZSN - varies based on soil properties, calibration parameter
• NSUR - varies by landuse
• INTFW - varies based on soil properties, calibration parameter
• IRC - varies based on soil properties, calibration parameter
• LZETP - varies based on soil properties and land cover, calibration parameter

• CEPS
• SURS
• UZS
• IFWS
• LZS
• AGWS
• GWVS

QUAL-INPUT - Pollutant buildup information

• SQO
• ACQOP - varies for each pollutant and for each landuse, calibration parameter
• SQOLIM - varies for each pollutant and each landuse, calibration parameter
• WSQOP - varies for each pollutant and each landuse, calibration parameter
• IOQC - varies based on soil properties and landuse, calibration parameter
• AOQC - varies based on subsurface properties, calibration parameter

 Parameters are displayed for the IMPLND module in the same manner as for PERLND.

 NOTE: The active modules of IMPLND segments for hydrologic and general water quality simulation are:

• ATMP
• IWATER
• IQUAL

 Same as PERLND

IWATER parameters:

IWAT-PARM2 - Surface characteristics

• LSUR - varies by watershed, calibration parameter
• SLSUR - varies by geographic location, calibration parameter
• NSUR - varies by landuse, calibration parameter
• RETSC - varies based on land cover, calibration parameter

• PETMAX
• PETMIN

• RETS
• SURS

QUAL-INPUT - Pollutant buildup information

• SQO
• ACQOP - varies for different pollutants and landuses, calibration parameter
• SQOLIM - varies for different pollutants and landuses, calibration parameter
• WSQOP - varies for different pollutants and landuses, calibration parameter

These materials may be used for study, research, and education, but please credit the authors and the Center for Research in Water Resources, The University of Texas at Austin. All commercial rights reserved. Copyright 1998 Center for Research in Water Resources.