Over the past 20 years, the Soil and Water Assessment Tool (SWAT) has become widely used across the globe. The large numbers of applications across the globe have also revealed limitations and identified model development needs. Numerous additions and modifications of the model and its individual components have made the code increasingly difficult to manage and maintain. In order to face present and future challenges in water resources modeling SWAT code has undergone major modifications over the past few years, resulting in SWAT+, a completely revised version of the model.

Even though the basic algorithms used to calculate the processes in the model have not changed, the structure and organization of both the code (object based) and the input files (relational based) have undergone considerable modification. This is expected to facilitate model maintenance, future code modifications, and foster collaboration with other researchers to integrate new science into SWAT modules. SWAT+ provides a more flexible spatial representation of interactions and processes within a watershed.

User Groups

Because there are 3 distinct pieces to SWAT+, we have created user groups for each. Please identify which area you are having difficulty with and choose the appropriate group:

QSWAT+ user group For issues defining your watershed in QGIS and using the QSWAT+ plugin.

SWAT+ Editor user group For issues related to the editor interface.

SWAT+ model user group For questions and discussion related to the model itself, not the editor or GIS interfaces.

Bug/Issue Reporting

For SWAT+ Editor bugs or issues, report to the user groups or the Bitbucket issue tracker.

What you'll need

The following guide will show you how to get started with SWAT+ Editor. This guide does not cover how to set up your watershed in QSWAT+. Please refer to the QSWAT+ manual for this step.

Demo project files

Please use the following Robit demo project, which has already been set up in QSWAT+. Alternatively, you may use the Robit project you set up on your own after following the steps in the QSWAT+ manual.

Watch the SWAT+ Editor guide video

Please watch the guide video before launching SWAT+ Editor. This video will quickly walk you through the steps needed to bring your QSWAT+ project into the editor, as well as show you how to catch and report errors. If you prefer a written guide instead of or in addition to the video, a walk through is shown below.

Walk through guide for SWAT+ Editor

If you do not want to watch a video, follow the steps below. This guide shows the basic steps you need to take to set up your model, but does not cover all input parameters available through the editor. Please refer to the SWAT+ Editor documentation section for help editing specific input parameters.

Set up your project in QSWAT+

Follow the QSWAT+ manual to set up your watershed. To open SWAT+ Editor from within QSWAT+, click the button for Step 3: Edit Inputs and Run SWAT.

Open your project in the editor

The first time your open your QSWAT+ project in SWAT+ Editor, your data must be imported from the GIS tables into SWAT+ database format. This may take a few seconds to several minutes depending on the size of your watershed.

When your GIS data is done loading, your project will be displayed in the light blue box in the top center of the editor. Click the start editing SWAT+ inputs button to begin.

Edit SWAT+ inputs

The first step you should take is to add weather generator (WGN) data. It may be imported from the distributed WGN database in the SWAT+ Tools installer, or from CSV files. Go to the weather generator section and click the import data button as shown in the screenshot below.

The database import option is selected by default, with the global CSFR weather generator table chosen. Click in the box to see other table options. wgn_us is weather generator data for the United States. wgn is an empty table you may populate with your own data if desired.

Alternatively, select CSV files from the top pull-down menu. In the Robit demo dataset, we have provided CSV files to use for weather generators, located in the Wgn folder of the sample project linked at the top of this page. Select these files in the editor as shown in the screenshot below, then click the start import button.

You should now see one weather generator station added. Next, we need to add observed weather data. From the left menu in the editor, click the Weather Stations link.

Click the import data button to import your files. In the Robit demo dataset, we have provided weather data in SWAT2012 format in the Weather directory. Select this folder as the SWAT2012 weather files directory in the editor's import form. You may also choose where to save the files when they are converted to SWAT+ format. By default, your TxtInOut folder is selected. Click the start import button to continue.

Once your data has been converted to SWAT+ format and imported to your project, we've also automatically adjusted your simulation dates. From the left menu in the editor, under the Simulation heading, click on Time. You may alter your simulation starting and ending times, however make sure they fall within the range of your observed weather data. If you have made any changes, click the save changes button.

Next, select what data you want to print from your simulation. We advise not printing all daily output files as the file size can be very large and take a long time to import to the database for visualization. For the Robit demo, please change the number of skip years to 3, then check the boxes to print all monthly and annual output. Click the save changes button when done.

This concludes the last required section for editing SWAT+ inputs before writing files and running the model. The remaining sections are not covered in this walk-through, however you can look through the SWAT+ Editor Documentation section for more information.

In this demo, we'll go ahead and proceed to the next step: writing SWAT+ input files. From the navy ribbon on the left side of the editor, click on the pencil icon. Choose your location to write the files, then click the save and write files button.

When done, from the navy ribbon on the left side of the editor click the next step with the triangle/play icon to run the model. By default, the release version of the model is run. If you encounter an error, you can come back and check the box to run in debug mode to get a detailed error message from the model.

After the model run has finished successfully, from the navy ribbon on the left side of the editor, click the graph icon. From here you can import your model output text files into a SQLite database for use with the QSWAT+ visualization tool. Output may take a long time to import depending on the length of your simulation, the output files selected from the Simulation->Print section, and the size of your watershed.

When the editor finishes importing your output, you may close the editor by clicking the X in the top right of the editor window, or by going to File->Exit from the editor's menu.

You may now proceed to QSWAT+ step 4: visualization. Please refer to the QSWAT+ manual for more information about this process.

I received an error setting up my watershed in QSWAT+

Make sure you have installed the most recent version of QSWAT+ and followed the manual's installation instructions closely.

If you received an error during steps 1, 2, or 4 of the QSWAT+ interface, please consult the QSWAT+ user group. Check existing questions to see if anyone else had the same problem. If not, please post your error and be as descriptive as possible about what you were doing when you received the error message.

I received an error in SWAT+ Editor

SWAT+ Editor is most often accessed during step 3 of the QSWAT+ plugin. It may also be launched on its own. Make sure you have installed the most recent version of SWAT+ Editor.

If your error is not covered by the solutions below, please consult the SWAT+ Editor user group.

There was an error checking your project configuration

If you receive this message when you first launch your project in the editor, it is a sign the editor did not load its services correctly. While SWAT+ Editor is running, please right-click your Windows taskbar and select Task Manager. Expand the arrow next to SWATPlusEditor and ensure you have swatplus_rest_api.exe running as shown in the screenshot below.

If you do not see it running, please open a command prompt window. Make sure you are in the C drive, or the drive where you installed SWAT+. Browse to the location below, then run the swatplus_rest_api.exe file.

> cd C:\SWAT\SWATPlus\SWATPlusEditor\resources\app.asar.unpacked\api_dist
> swatplus_rest_api.exe

If it is working properly, you should receive something similar to the following:

* Serving Flask app "swatplus_rest_api" (lazy loading)
* Environment: production
WARNING: Do not use the development server in a production environment.
Use a production WSGI server instead.
* Debug mode: off
* Running on http://127.0.0.1:5000/ (Press CTRL+C to quit)

If this is what you received, please simply close SWAT+ Editor and try launching it again.

If you get no message on the screen at all, it might be a permission or error related to your computer settings. Try installing to another location on your machine, such as another hard drive, or even install to a flash drive. If this still does not work, try another machine.

If you receive an error message, please copy it and report to the Bitbucket issue tracker.

I received an error importing GIS data or updating my project

Please post the error message to the SWAT+ Editor user group AND include your project files. This error is likely project specific and we cannot help you without seeing your project files.

Other SWAT+ Editor errors

If you receive any other error messages from SWAT+ Editor, from its menu go to View -> Toggle Developer Tools. In the windows that pops open, toggle the Console tab and take a screenshot or copy an errors received and post to the SWAT+ Editor user group.

I received an error running the SWAT+ model

If you received an error running the model, first make sure you have run it in debug mode and checked the detailed error received. If you are not able to make sense of the source of the model error, please post to the SWAT+ model user group AND include your project files. This error is likely project specific and we cannot help you without seeing your project files.

Click the paper icon in the leftmost blue toolbar to enter the editing section. Most editors in this section are a literal representation of the SWAT+ input files. The collapsible dark-gray headings on the left correspond to the section lines in the master watershed file (file.cio).

When you click on an editor section from the left menu, you'll find the default SWAT+ file name with which the section corresponds. This enables you to quickly look up further information in the SWAT+ input/output documentation.

Navigating the Editor

Most data is presented in a tabular format. When you click a row, you're presented with a form where you can make changes and save. The following features are common across many editor sections.

Action Bar

At the top of most tables, you'll see the following action bar. Not all sections will have each option available.

Click create new record to add an item to the table. Edit multiple records allows you to set a single value for one or more fields across all or selected rows in your table.

In the search box, start typing the name of the object you want to view. Matching options will appear below the text box. Click the one you want, then click the search icon button to the right.

The import/export data button allows you to quickly access your data in CSV (comma-separated values spreadsheet) format, in most cases. We recommend exporting your data (or empty table is okay) first to get a template with the column names. You may then modify the file and import it back into the editor.

Tables

Sort by a column in the table by clicking on the heading name. It will toggle ascending or descending direction as indicated by the arrows next to the name.

Tables with many records can be scrolled and then paged by clicking the page number or arrow links at the bottom of the table.

Each row may contain an edit/view icon on the far left to access the data in the row, and a delete icon on the far right (may need to scroll to access the far right of the table). We do not recommend deleting rows unless you are absolutely sure they are not used elsewhere in your model. Due to the relationships of data in SWAT+, deleting records could have unintended effects and break your model. Deleting cannot be undone; if in doubt, make a backup of your project SQLite database first.

Forms

Most objects in SWAT+ have a name field and are identified using this name. Names should be unique and not contain spaces (spaces will be automatically converted to underscores).

Each form will have a save changes button toward the bottom. Be sure to click this button after making any changes and before leaving the form.

Look-up Fields

There are a lot of relationships between objects in SWAT+. For example, all fields in your channel properties table link to rows in other tables. In SWAT+ Editor forms, you can easily select these related rows by starting to type an object's name and select it as it pops up. If you accidentally enter an incorrect name, the editor will return an error stating the record does not exist in your database.

Getting Started

We recommend starting in the climate section, and importing your weather generators and observed weather data. If you're coming from GIS, when you import weather generators or observed data, it will create weather stations and match them to your spatial objects automatically.

SWAT+ revision 59.3

Download the revision notes for the model below.

QSWAT+ revision 1.2.2

• Environmental flows have been added.

• Revised treatment of ponds and reservoirs.

SWAT+ Editor revision 1.2.3

• Fixed bug in reading output file headers

• Fixed bug that allowed user to run model without adding weather generator data

• Added rotation year to management operation schedule

• Updated SWAT+ rev. 59.3 to fix bug where it wasn't printing all IDs in lsunit output files

SWAT+ Editor revision 1.2.2

• Fixed bug in writing aqu_catunit.ele where basin fraction would be 0 for small areas

• Fixed various bugs while importing GIS data

• Updated model rev. 59.3 with various bug fixes

• Improved weather and wgn importing speed when matching to connect objects

• Limit map view in connect pages to avoid display locking in large projects

• When writing inputs, changed bsn_frac column to exponential format for better precision

SWAT+ Editor revision 1.2.1

• Small fix for projects using barren land use.

• Fixed bug when receiving an error trying to edit a row in landuse management.

SWAT+ Editor revision 1.2.0

• Compatible with SWAT+ rev. 59.3

• Fixes default routing in rout_unit_con for upland to floodplain surface runoff. Use fraction of area of upland routing unit surface runoff goes to channel/reservoir, the remaining goes to floodplain (see Bieger et al. JAWRA 2019). New projects only, existing projects should try re-import from GIS option.

• Change aquifer creation. Previously created one aquifer per channel. Changed to two per subbasin (upland/floodplain), and add a deep aquifer for each outlet.

• Fixes default principal/emergency area and volume of reservoirs. Note: new projects / re-import GIS data only. Existing projects should update values manually as needed. New defaults are described below:

  • Principal spillway area (area_ps) is set from GIS data

  • Emergency spillway area is set to area_ps * 1.15

  • Principal spillway volume is set to area_ps * 10

  • Emergency spillway volume is set to area_es * 10

• Un-managed ponds are now retained as HRUs in QSWAT+. Imported to the editor as HRUs with wetlands inputs (wetlands_wet and hydrology_wet).

• Update output database tables to include revisions from model rev. 59.3: channel and channel morph, reservoir, and wetlands columns.

• Project update function available for the following data changes related to model rev. 59.1-3:

  • Update cal_parm_cal abs_max=10 and units=m for flo_min and revap_min. Add dep_bot.

  • Update aquifer_aqu default values for gw_flo=0.05, dep_wt=10, flo_min=5, revap_min=3.

  • In plant_ini_item, yrs_init changed to fraction (change values to 1 where previously 15), and biomass increased for some plants. Lc_status changed to yes for past and barr plants.

  • Update codes_bsn default values for pet=1, rtu_wq=1, wq_cha=1

• User interface improvements:

  • Add csv import for weather generator data.

  • All related table search boxes return all possible results underneath matches to typed text.

  • Add automatic database rollback when user gets an error importing GIS or updating project.

• Bug fixes:

  • Fixed bug when updating project from 1.0.0, a variable was not declared.

  • Fixed bug where weather stations were created but not always assigned weather data file if one exists.

  • Fixed bug when trying to import weather data located on another hard drive.

  • Fixed bug where swatplus_rest_api.exe wasn't terminating correctly when exiting the editor.

SWAT+ Editor revision 1.1.1

• Fixes bug when importing GIS data into plant communities not in the datasets database

• Print section usability update

• Update automatic project database backups so multiple failed import/upgrade attempts don't overwrite the original

SWAT+ Editor revision 1.1.0 changes from 1.0.0

The remainder of this page outlines what changed from the initial release of the editor in fall 2018 to version 1.1.0 released in spring 2019. If you never used version 1.0.0, you can skip the remainder of this page.

• Upgrade function available for projects made with version 1.0.0.

• Compatible with SWAT+ rev. 59.

• Re-designed project setup page. If importing GIS, allow SWAT+ lte option for projects without point source or reservoir data.

• Channels now default to using the channel-lte structure (as per SWAT+ rev. 58). Please note that this means your channel input files are different (chandeg.con) and the channel output will be in channel_sd tables.

• New editor sections for: basin parameters, connections--export coefficients, recall, delivery ratio, landscape unit regions, land use management, calibration, initialization data, soils, databases, and structural.

• Added export/import to and from CSV files for most sections.

• Other miscellaneous usability improvements.

• Automatic updating for more rapid bug fixes and releases.

Notable limitations

• Constituents (pesticides, pathogens, heavy metals, salts) are not fully available through the editor yet.

Project database changes

• d_table_dtl - add column file_name, repopulate table based on 4 new decision table files: lum.dtl, res_rel.dtl, scen_lu.dtl, flo_con.dtl

• d_table_dtl_act - add column const2

• d_table_dtl_act - rename columns application->fp and type->option

• recall_dat - drop columns sol_pest, srb_pest, p_bact, lp_bact, metl1, metl2, metl3

• exco_om_exc - drop columns sol_pest, srb_pest, p_bact, lp_bact, metl1, metl2, metl3

• exco_om_exc - rename columns ptl_n->orgn, ptl_p->sedp, no3_n->no3, sol_p->solp, nh3_n->nh3, no2_n->no2, bod->cbod, oxy->dox, sm_agg->sag, lg_agg->lg_agg

• aquifer_aqu - drop columns gw_dp, gw_ht, delay

• aquifer_aqu - add columns dep_bot (default value 10), dep_wt (default value 5), bf_max (default 1)

• aquifer_aqu - change spec_yld value from 0 to 0.05

• aquifer_aqu - add column init_id referencing initial_aqu

• fertilizer_frt - drop columns p_bact, lp_bact, sol_bact

• fertilizer_frt - add column pathogens

• hydrology_hyd - drop column dp_imp

• pesticide_cha - rename column sed_conc->pst_solub

• channel_lte_cha - rename table to hyd_sed_lte_cha

• hru_data_hru - drop column soil_nut_id

• hru_data_hru - add column soil_plant_init_id

• cal_parms_cal - change column type of units from number to text

• initial_cha - drop existing columns, add new columns: org_min_id, pest_id, path_id, hmet_id, salt_id (foreign keys to new tables in init)

• initial_res - drop existing columns, add new columns: org_min_id, pest_id, path_id, hmet_id, salt_id (foreign keys to new tables in init)

• reservoir_res - drop column pest_id

• wetland_wet - drop column pest_id

• sediment_res - add columns carbon and bd

• plants_plt - drop column plnt_hu and add column days_mat

• plant_ini - add column rot_yr_ini

• codes_bsn - change column type of atmo_dep from number to text

• rout_unit_ele - drop column hyd_typ, change foreign key of rtu_id from rout_unit_rtu to rout_unit_con

• constituents_cs - drop and re-create table

• dr_om_del, dr_pest_del, dr_path_del, dr_hmet_del, dr_salt_del, delratio_del - drop and re-create tables

• calibration_cal - drop and re-create table

• pesticide_pst - drop and re-create table

• codes_cal - rename table codes_sft, replace columns landscape and hyd with hyd_hru and hyd_hrulte

• ls_parms_cal - rename table wb_parms_sft

• ch_parms_cal - rename table ch_sed_parms_sft

• pl_parms_cal - rename table plant_parms_sft

Drop tables

• pest_soil_ini

• pest_soil_ini_item

• path_soil_ini

• hmet_soil_ini

• salt_soil_ini

Add new tables

• soil_plant_ini

• om_water_ini

• pest_hru_ini

• pest_hru_ini_item

• pest_water_ini

• path_hru_ini

• path_water_ini

• hmet_hru_ini

• hmet_water_ini

• salt_hru_ini

• salt_water_ini

• channel_lte_cha (new structure; not the same as old table renamed to hyd_sed_lte_cha)

• initial_aqu (same structure as initial_cha)

• calibration_cal_cond

• calibration_cal_elem

• water_balance_sft and water_balance_sft_item (replace ls_regions_cal)

• ch_sed_budget_sft and ch_sed_budget_sft_item (replace ch_orders_cal)

• plant_gro_sft and plant_gro_sft_item (replace pl_regions_cal)

SWAT+ Datasets database changes

• d_table_dtl - add column file_name, repopulate table based on 4 new decision table files: lum.dtl, res_rel.dtl, scen_lu.dtl, flo_con.dtl

• d_table_dtl_act - add column const2

• d_table_dtl_act - rename columns application->fp and type->option

• plants_plt - drop column plnt_hu and add column days_mat

• Replace all decision table data

• Replace all plants_plt data

• Replace all fertilizer_frt data

• Replace all pesticide_pst data (also new table structure)

• Replace all var_range data

• Add new tables: version, tropical_bounds

Output database changes

• New naming structure based on SWAT+ rev. 56

General watershed attributes are defined in the basin input files: codes and parameters. These attributes control a diversity of physical processes at the watershed level. The interfaces will automatically set these parameters to the default or recommended values listed in the variable documentation. Users can use the default values or change them to better reflect what is happening in a given watershed. Variables governing bacteria or pesticide transport need to be initialized only if these processes are being modeled in the watershed. Even if nutrients are not being studied in a watershed, some attention must be paid to these variables because nutrient cycling impacts plant growth which in turn affects the hydrologic cycle.

Codes

codes_bsn

Parameters

parameters_bsn

Time

Configure the number or years to run the simulation and time step. If you have observed weather data, make sure your simulation time falls within these dates.

time_sim

Configure the output files to print.

print_prt

print_prt_object

Each row in print_prt_object represents an output file that can be print daily, monthly, yearly, and average annual output for each.

Print Object Descriptions

Repository Links

• SWAT+ source code repository

• SWAT+ Editor source code repository

• QSWAT+ source code repository

Run and Compile SWAT+ Editor

Install Development Tools

• You may use any IDE of your choice, however Visual Studio Code is used by the developer.

• Install Python 3.7

• Install required Python packages. From command prompt, go to source code /api directory and run:

pip install -r requirements.txt

• Install Node.js

• Install required Node.js packages. From command prompt, go to the root directory of the source code and run:

npm install

Run the Source Code

From a command prompt in the root directory (terminal inside Visual Studio Code)

npm run dev

Open a second command prompt and run

npm run electron

Build the Source Code

First, use PyInstaller (included in the Python packages during install) to freeze the Python into executable files. This should be done from the /api directory in the source code. In Windows, run the supplied .bat file from a command prompt:

pyinstaller_builds

Next, build the Vue.js code. Open a command prompt and run:

npm run build

Finally, package the code for distribution using Electron Builder. Configuration is set in the package.json file. Results of the build will be placed in the /release/dist directory.

Create an installer:

npm run dist

Or, build a portable executable:

npm run dist-port

Or, pack the files into a directory:

npm run pack

Special note about using export coefficients with constant point source/inlet data

In SWAT+, constant values for point sources and inlets are stored in the export coefficients properties file, exco.exc, while time series data are stored entirely in the recall section.

However, in the editor, we keep both constant and time series point sources and inlets in the recall section. When you write input files, the editor will write to the exco.exc and exco_om.exc files appropriately.

When you are done editing your input data, click the pencil icon in the leftmost blue toolbar to go to the write input files section. Select the directory to save your files (if coming from GIS, your default scenario TxtInOut directory is chosen by default), and click the save and write files button.

A progress bar will pop up showing the files being written. When complete, you can proceed to the next step: running the model. Click the arrow button in the leftmost blue toolbar.

If you need to make additional changes to your SWAT+ input data, be sure to come back to this step and re-write your files before running the model again.

Weather Stations

Weather stations are linked from all of your connection objects (channels, HRUs, etc.) in SWAT+. If you are coming from QSWAT+, it is much better to import stations either from the weather generator section, or the observed weather file importer than it is to create them manually.

By importing through one of the methods described below, your new stations will be automatically matched your spatial connection objects.

Import Weather Generator Data

Click the import data button to import weather generator (wgn) data for your project. If you installed the SWAT+ databases, this file will be selected by default along with the CFSR world table. USA wgn data is also available from this database; type wgn_us to use this table.

You may also add your own data to this database using the wgn and corresponding wgn_mon tables.

Below the table name field is a check box asking if you are using observed weather data. By default (unchecked), when you click start import, weather stations will be created based on your wgn locations. If you are using observed weather data and prefer to have weather stations created based on this data, check this box--stations will not be created when you start import, and instead they will be created for you when you import your observed weather data files.

If you are not using observed weather data, it is important to leave the box unchecked so that weather stations are created for you.

CSV Import

If you do not want to use the SQLite database, you may import CSV files of your weather generator data. Two CSV files are required.

1. Stations CSV file:

   • Columns id, name, lat, lon, elev, rain_yrs

   • id should be uniquely numbered

2. Monthly values CSV file:

   • Columns id, wgn_id, month, tmp_max_ave, tmp_min_ave, tmp_max_sd, tmp_min_sd, pcp_ave, pcp_sd, pcp_skew, wet_dry, wet_wet, pcp_days, pcp_hhr, slr_ave, dew_ave, wnd_ave

   • id should be uniquely numbered

   • wgn_id corresponds to the id column from the stations file

Import Observed Weather Data

Import observed weather data from the top of the weather stations section. The data files may be in one of two formats: SWAT2012/Global Weather Data CFSR website format, or SWAT+.

SWAT2012/Global Weather Data CFSR Website Format

Each measurement included in your data must have the following entry file names:

Each entry file is a comma-separated list of stations. Each station name should have a corresponding .txt file (e.g., name p326-963 should have a p326-963.txt file).

Each station file should have the first line as the starting day as YYYYMMDD (e.g., 19790101). The following lines are the measurement for each day, one line per day. For temperature, each line will be max,min (e.g., 10.138,-2.662).

Weather data may be downloaded from the Global Weather CFSR website.

SWAT+ Format

Each measurement included in your data must have the following entry file names:

Each entry file has a title line (any text allowed), followed by a heading line, followed by a list of filenames for each station. Filenames should be listed alphabetically.

Each station file has a title line, followed by a heading line and data line for time and location. Measurements for each timestep are in the lines to follow. For temperature, the measurements will be listed as max then min.

Weather Generator Parameters

weather_wgn_cli

weather_wgn_cli_mon

Each entry in weather_wgn_cli will have 12 rows in weather_wgn_cli_mon.

Weather Stations Parameters

weather_sta_cli

When entering an observed weather file name in the station editor, you may start typing to search for existing weather files adding during the import step. If adding observed files manually, just type the name of the file (e.g., p326953.pcp), and put that file in the directory you plan to write input files (e.g., your TxtInOut). Files must be in SWAT+ format. If your weather data is in SWAT2012 format or from the Global Weather CFSR website, please use the import step to convert them to SWAT+.

weather_file

This table is only used if you import observed weather data files. If entering stations manually, this table will not be populated.

Need to access this documentation offline? Please download a PDF export of this documentation website linked below. We recommend you also make sure you have downloaded a copy of the QSWAT+ manual and SWAT+ input docs.

The connections section contains all spatial object connectivity for the simulation run. In SWAT+ Editor, all connection object properties can be set through this section. For example, when you click on channels, you will see additional menu links appear for: properties, initialization, hydrology and sediment, and nutrients.

All connection objects have a similar format as seen in the above figure. The tabular view is shown by default. Click the map view tab to see a map with markers for the center coordinates of each object. Click an object marker in the map view, or edit icon on the left side of a row in the table to view or edit the object.

Each connection object will have a main properties object associated with it as well as a weather station. Click on these names in the table, or from the edit view page, click the button next to their names to view information about the properties object or weather station.

Each connection object may have outflow. This can be viewed in the table by clicking the eye icon in the rightmost column, or view from the edit page.

If you imported your project from GIS, your connection objects are populated automatically during project setup.

Explanation of SWAT+ Spatial Objects

Subbasin

The subbasin is defined by the DEM in the GIS interface as it always has been. All flow within the subbasin drains to the subbasin outlet.

Landscape Unit

A landscape unit (LSU) is defined as a collection of HRUs and can be defined as a subbasin, or it could be a flood plain or upland unit, or it could be a grid cell with multiple HRUs. The landscape unit is not routed, it only used for output. The landscape unit output files (waterbal, nutbal, losses, and plant weather) are output for HRUs, landscape units, and for the basin. Two input files are required: 1) landscape elements and, 2) landscape define. The elements file includes HRUs and their corresponding LSU fraction and basin fractions. The define file specifies which HRUs are contained in each LSU.

Routing Unit

A routing unit is a collection of hydrographs that can be routed to any spatial object. The routing unit can be configured as a subbasin, then total flow (surface, lateral and tile flow) from the routing unit can be sent to a channel and all recharge from the routing unit sent to an aquifer. This is analogous to the current approach in SWAT. However, SWAT+ gives us much more flexibility in configuring a routing unit. For example, in CEAP, we are routing each HRU (field) through a small channel (gully or grass waterway) before it reaches the main channel. In this case, the routing unit is a collection of flow from the small channels. We also envision simulating multiple representative hillslopes to define a routing unit. Also, we are setting up scenarios that define a routing unit using tile flow from multiple fields and sending that flow to a wetland.

The routing unit is the spatial unit SWAT+ that allows us to lump outputs and route the outputs to any other spatial object. It gives us considerably more flexibility than the old subbasin lumping approach in SWAT, and will continue to be a convenient way of spatial lumping until we can simulate individual fields or cells in each basin.

When you open SWAT+ Editor, you are taken to the project setup screen. If you are coming from QSWAT+, an overlay will appear with the paths to your project databases. You may edit these as needed, and click the start import button.

When your project is done importing from GIS, it will be selected as your current project and displayed in the recent projects sidebar on the left as well as in the center screen.

From here you can start editing your SWAT+ inputs by clicking the button in the middle, or by clicking the paper icon in the far left blue-colored menu.

SWAT+ lte

SWAT+ lte is a version of the SWAT+ model that greatly simplifies hydrology and plant growth and does not simulate nutrients, concentrating on gully formation and stream degradation. It only uses channel and HRU objects, so this option is not available if you have point source or reservoirs.

If your project in QSWAT+ does not have point source or reservoirs, you will have an option to set up your project for SWAT+ lte by checking the box. Otherwise, this option is hidden.

Other options for opening a project

If you are not coming from QSWAT+, you may open the editor and choose from one of three options:

Open project allows you to select an existing SWAT+ Editor project settings file and load it into the editor. Please note that this is an existing editor project, not any SWAT+ project. You must have an existing .json file for this option to work.

Click QSWAT+ project to select your QSWAT+ project database file. From here the steps are the same as described above when coming directly from QSWAT+.

Click new empty project to start a SWAT+ project from scratch, or if you have an existing SWAT+ project database but no settings file. If creating from scratch, leave the project database field blank and it will be created for you.

Recall objects are used for connecting point source or inlet data to your watershed. If you added point source in QSWAT+, when you import your project into SWAT+ Editor it will be connected via the recall section.

By default, constant data with all zero values during the default simulation period is added. To add your own recall data, click the recall item in the edit menu under connections. Click the item name under the rec column in the connection object table, or click the data item under recall in the edit menu on the left.

Constant Data

By default, your recall data is imported as constant. To insert your values, you can edit each item individually by clicking the edit button and manually entering each value. Alternatively, you may upload a CSV of your data.

From the recall data section, click the import/export button in the top right corner.

Export is selected by default. Choose a file name, and click the export CSV file button to get a template for your data.

Edit the CSV as needed, save, and then go back to the editor and click the import/output button again. This time toggle the import button. Choose your modified CSV file and click the import CSV data button. Your updated values will appear in the table.

Time Series Data

By default recall data is imported as constant, however this can be changed by clicking the edit button next to a row in the recall data table. Select the new time step for your data: daily, monthly, or yearly. Click the save changes button. Next, click the import/export button that appears on the form.

Export is selected by default. Choose a file name, and click the export CSV file button.

To import your data, click the import/export data button again and this time click to toggle import. Choose your file and click import CSV file. Your new data will appear in the table.

Recall Table Definitions

Each record in recall_rec will have a data file named {name}.rec. All of this data is stored in a single recall_dat table in the database.

A primary goal of environmental modeling is to assess the impact of human activities on a given system. Central to this assessment is the itemization of the land and water management practices taking place within the system. This section contains input data for planting, harvest, irrigation applications, nutrient applications, pesticide applications, and tillage operations. Information regarding tile drains and urban areas is also stored in this file.

In addition to the above, SWAT+ Editor groups the operations databases in this section of the editor. However, within the SWAT+ master watershed file (file.cio), these are listed under the ops section.

Land Use Management

This section is the entry point for management data in SWAT+. It comprises cross-walks to several other sections of data.

This data is accessed from the HRU properties section (hru-data.hru).

landuse_lum

Management Schedules

Management schedules comprise auto-schedules (decision tables) and/or operations schedules.

When you import your project from GIS, SWAT+ assigns auto-schedules for management based on your crop land use.

For example, oats is a cold annual crop. If this crop is in your HRUs, a decision table named pl_hv_oats will be created based on the template of pl_hv_wwht when you import your data from GIS.

Adding/Editing a Schedule

From the management schedules section, click create a new record or click edit on a row in the table. Give your schedule a unique name.

To add an automatic schedule, start typing a decision table name in the box provided. Click the desired result from the list of matches that pops up, and click the add button. If you enter more than one schedule, you can drag and drop to sort.

To add an operation, click the add operation button. Select your operation type from the form that pops up and complete the remaining fields. Click save when done to add the operation to your table.

When you're done adding automatic schedules and operations, click the save changes button to save your management schedule.

Table Parameters

management_sch

management_sch_auto

management_sch_op

Operations Types

Operation Data 1 Values

Operation Data 2 Values

Operations Databases

Values in the operations tables are provided in the SWAT+ datasets database and copied to your project database during project setup. You may modify them or add new rows as needed in the editor.

Harvest

Graze

Irrigation

Chemical Application

Fire

Sweep

Curve Number Table

Values in this table are provided in the SWAT+ datasets database and copied to your project database during project setup. You may modify them or add new rows as needed in the editor.

Conservation Practices

Values in this table are provided in the SWAT+ datasets database and copied to your project database during project setup. You may modify them or add new rows as needed in the editor.

Overland Flow Manning's n

Values in this table are provided in the SWAT+ datasets database and copied to your project database during project setup. You may modify them or add new rows as needed in the editor.

Decision tables are a precise yet compact way to model complex rule sets and their corresponding actions. Decision tables, like flowcharts and if-then-else and switch-case statements, associate conditions with actions to perform, but in many cases do so in a more elegant way (see on decision tables).

Structure of decision tables:

1. Conditions

2. Condition alternatives

3. Actions

4. Action entries

Each decision corresponds to a variable, relation or predicate whose possible values are listed among the condition alternatives. Each action is a procedure or operation to perform, and the entries specify whether (or in what order) the action is to be performed for the set of condition alternatives the entry corresponds to. Many decision tables include in their condition alternatives the "don’t care" symbol, a hyphen. Using "don’t cares" can simplify decision tables, especially when a given condition has little influence on the actions to be performed. In some cases, entire conditions thought to be important initially are found to be irrelevant when none of the conditions influence which actions are performed.

Usage in SWAT+

There are four decision table sections in SWAT+: land use management, reservoir release, scenario land use, and flow conditions.

See the land use management documentation, under management schedules for how to choose a decision table for your HRUs.

Reservoir release decision tables are assigned from the reservoir properties section under connections in SWAT+ Editor.

Modifying Decision Tables in SWAT+ Editor

In the current version of SWAT+ editor, we do not have a GUI available for editing decision tables, however we have provided the ability to export the decision table file. You may then make changes to it in a text editor, and upload back into SWAT+ Editor.

Table Definitions

d_table_dtl

d_table_dtl_cond

d_table_dtl_cond_alt

d_table_dtl_act

d_table_dtl_act_out

Text File Example and Explanation

The following is an example of a decision table in the lum.dtl input file. It is a table for warm season annual crops, using continuous corn.

In the above table, there are 6 conditions, 4 alternatives and 3 actions.

Description of the conditions

1. soil_water – if soil water is too high (> 1.50*field capacity), it will be too wet to operate machinery

2. plant_gro – (“n”) Planting allowed if plant is not growing.

3. phu_base0 – (0.15) when the sum base zero heat units for the year (starting Jan 1) exceeds 0.15, indicating it’s warm enough to plant

4. phu_plant – (1.15) harvest is scheduled when the sum of the heat units for the crop exceed 1.15 (if the heat units to maturity for the crop = 1500, then harvest would be scheduled at 1.15 * 1500 = 1725).

5. year_rot – needed to identify the current year of rotation. In this example, corn is grown in year 1.

6. days_plant – days since last plant (200) to ensure harvest occurs before next crop is planted.

Description of the alternatives

If all of the conditions for each alternative are met, outcomes are checked for ‘y’ to take action. Alternatives with dash (‘-‘) are not checked.

1. plant corn based on heat units: if soil water < 1.50*fc and if phubase0 > 0.15*phu_mat and if year_rot = 1 then check outcomes for ‘y’ and if ‘y’, take that action (plant)

2. Harvest corn based on crop accumulated heat units: if soil_water < 1.50*fc and if phu_plant > 1.15*phu_mat and if year_rot = 1 and then check outcomes for ‘y’ and if ‘y’, take that action (plant)

3. Harvest corn based on days since planting: if year_rot = 1 and if days_plant =200 then check outcomes for ‘y’ and if ‘y’, take that action (harvest)

4. Reset rotation year: if year_rot > 1 then check outcomes for ‘y’ and if ‘y’, take that action (rot_reset)

Description of the actions

1. plant: corn – cross walked to plant name in plants.plt file

2. harvest_kill: corn – cross walked to plant name in plants.plt file grain – relates to harvest type in harv.ops file

3. rot_reset: rotation reset – for continuous corn (1 year rotation). The rotation year is reset to 1 at the end of every year.