SWAT操作手册

BASINS Extension - Model - SWAT

by M. Di Luzio, R. Srinivasan and J.G. Arnold

Purpose

The SWAT ArcView extension for BASINS is a graphical user interface for SWAT (Soil and Water Assessment Tool)model (Arnold et al., 1998). SWAT model is a river basin, or watershed, scale model developed to predict the impact of land management practices on water,sediment（沉积物）,and agricultural chemical yields in large,complex watersheds with varying soils,land use,and management conditions over long periods of time.The model is physically based and computationally efficient, uses readily available inputs and enables users to study long-term impacts. For a detailed description of SWAT, see Soil and Water Assessment Tool User's Manual, Version 2000 (Neitsch et al., 2000), published by the Agricultural Research Service and the Texas Agricultural Experiment Station, Temple Texas.

The SWAT model can be applied to support various watershed and water quality modeling studies.Examples of such studies include the following:

?National and regional scale water resource assessment considering both current and projected management conditions. 在当今和未来的管理条件下，对全国和区域尺度上的水资源评估，

?Bosque（丛林）River TMDL in Erath County, Texas. The project determined sediment, nitrogen and phosphorus loadings to Lake Waco from various sources including dairy waste application areas,waste treatment plants,urban areas,conventional row crops and rangeland（牧场，牧地）.Numerous land management practices were simulated and analyzed (Saleh et al., 2000)

?Poteau River TMDL in Oklahoma/Arkansas.This project assess determined sediment, nitrogen and phosphorus loadings to Wister Lake and dissolved oxygen（溶解

氧）,temperature,algae（水藻,海藻）,and CBOD（碳生化需氧量）in the river.

Management scenarios regarding poultry（家禽）waste were analyzed (Srinivasan et al., 2000).

?DDT in the Yakima River basin,Washington.SWAT was used to simulate past and future sediment contamination by DDT in the Yakima river basin.

?The EPA office of pesticide registration（农药注册局）is evaluating SWAT for use in landscape/watershed scale evaluation for pesticide registration.

?SWAT is being used extensively in the U.S.and Europe to assess the impact of global climate on water supply and quality (Rosenberg et al, 1999).

The SWAT ArcView extension for BASINS is a consistent evolution（一致的评估）of AVSWAT,an ArcView extension developed for an earlier version of SWAT (Di Luzio et al.,1998).

The BASINS SWAT interface extension requires the designation of land use（土地利用说明）,soil,weather,groundwater,water use,management,soil chemistry,pond, and stream water quality data,as well as the simulation period,to ensure a successful simulation.

Application

SWAT model can be used to simulate a single watershed or a system of multiple hydrologically connected watersheds.Each watershed is divided first in subbasins and then in hydrologic response units (HRUs)based on the land use and soil distributions. In BASINS the watershed boundaries（流域边界）can be defined through the BASINS Delineation extensions（BASINS流域划分）(see BASINS User's Manual, Sec. 8),while the HRU distribution can be defined exclusively using the Landuse and Soil Overlay and HRU distribution extension (see BASINS User's Manual, Sec. 9.1).For this reason, although the BASINS SWAT has been developed using Dialog Designer extension(ver. 3.1 or later)the installation requires Spatial Analyst (ver. 1.1 or later) and ArcView extensions installed on your PC.

Procedures

Key Procedures

?Load or select the SWAT extension (if not done) checking the relative box in the BASINS Extension Manager ('Models' category)

?Delineate the watershed (see BASINS User's Manual, Sec. 8) and define the HRUs (see BASINS User's Manual, Sec. 9.1)

?(Optional) Edit SWAT databases

?Define the weather data

?Apply the default input files writer

?(Optional) Edit the default input files

?Set up (requires specification of simulation period, PET calculation method, etc.) and run SWAT

?(Optional) Apply a calibration tool

?(Optional) Analyze, plot and graph SWAT output using GenScn

Before you Get Started

First, verify that the SWAT extension is active in your BASINS project by typing Ctrl+B from the BASINS View(or selecting the BASINS Extension choice in the File menu) and selecting the Models item from the Extension Categories dropdown list. The SWAT entry in the Basins Extensions list should be visible and selected (Screen 1).

Screen 1

If the SWAT entry is not selected (checked), click on it to select it.

The extension brings to the project a new View object with the designed graphical user interface (GUI) for SWAT model. The working view is SWAT View (Screen 2) and is actually introduced to the project when the user defines the HRUs distribution in the watershed with the SWAT option active (see BASINS User's Manual, Sec. 9.1).

Screen 2

Moreover the extension brings to BASINS View the following items:

1.Under the Utilities menu, the item SWAT Databases (Screen 3).

Screen 3

By selecting this item the user can access and edit several SWAT model data bases (see Sec. 11.1.1) that can be used within each BASINS project.

2.Under the Models menu, the SWAT item (Screen 4)

Screen 4

By selecting this item the user can pass from BASINS View to SWAT View, the graphical user interface (GUI) for the SWAT model.

3. A new item is added to the BASINS View pop-up menu（视图弹出菜单）. Right click

on the map display of the BASINS View to activate the pop-up menu (Screen 5)

Screen 5

By selecting this item the user can pass from BASINS View to SWAT View, the graphical user interface (GUI) for the SWAT model.

References

Arnold, J.G., Srinivasan, R., Muttiah, R.S., and Williams, J.R. 1998. Large area hydrologic modeling and assessment part I: model development. J. American Water Resources Association 34(1):73-89.

Di Luzio, M., Srinivasan R. and Arnold J.G, 1998. Watershed oriented non-point pollution assessment tool. In: Computers in Agriculture - 7th international conference. October 26-30th 1998, Orlando, FL. ASAE. 233-241.

Neitsch, S. , Arnold J.G. and Williams J.R., 2000. Soil and Water Assessment Tool User抯 Manual, Version 2000.

Rosenberg, N.J., Epstein, D.L., Wang, D., Vail, L., Srinivasan, R., and Arnold, J.G. 1999. Possible impacts of global warming on the hydrology of the Ogallala aquifer region. J. of Climate 42:677-692.

Saleh, A., Arnold, J.G., Gassman, P.W., Hauck, L.W., Rosenthal, W.D., Williams, J.R., and McFarland, A.M.S. 2000. Application of SWAT for the upper north Bosque watershed. Transactions of the ASAE 43(5):1077-1087.

Srinivasan, R., Arnold, J.G., Ramanarayanan, T.S., and Bednarz, S.T. 2000. Modeling Wister lake watershed with the soil and water assessment tool (SWAT) J. American Water Resources Association (in review).

1.0 SWAT Database Editors

Purpose

The SWAT model uses five databases to store required information about plant growth and urban land uses, tillage, fertilizer components and pesticide properties (See Soil and Water Assessment Tool User's Manual, Version 2000).The BASINS SWAT extension brings to the user, friendly dialog based editors (SWAT Database Editors) to access and edit these and two additional databases to store custom soils and custom weather station parameters.

Application

The SWAT Database Editors are available once BASINS SWAT extension is loaded.The user can start the editing session from two locations in the BASINS project:

1.From BASINS View,select the SWAT Databases item from the Utilities menu (see

Screen 1.1);

Screen 1.1

2.From SWAT View,select the Databases item from the Edit Input menu (see Screen

1.2).

Screen 1.2

A dialog pops up showing the list of the SWAT Database Editors (Screen 1.3).

Screen 1.3

Seven database items are listed: User Soils, User Weather Stations, Land Cover/Plant Growth, Fertilizer, Pesticide, Tillage, Urban:.

https://www.wendangku.net/doc/2718329610.html,er Soils: this database is used to store SWAT custom soil data. Data

are entered in this database when the used soil maps are not linked to the STATSGO soil database included with BASINS.

https://www.wendangku.net/doc/2718329610.html,er Weather Stations: this database is used to store SWAT statistical weather parameters for stations that are not in the US database included with BASINS.

https://www.wendangku.net/doc/2718329610.html,nd Cover/Plant Growth: this database contains SWAT plant growth parameters. Although you are given the option of modifying existing land cover/plant parameters or adding additional plant species to the

database, it should be noted that changes to the plant database should be based on experimental data. The typical user will not need to make changes to this database.

IV.Fertilizer: this database is used to store SWAT fertilizer parameters.

Both inorganic and organic (manure) fertilizer data are stored in this database. You are given the option of modifying existing and/or adding new fertilizer parameters. The typical user will not need to make changes to this database.

V.Pesticide: this database is used to store SWAT pesticide parameters. You are given the option of modifying existing and/or adding new pesticide parameters. The typical user will not need to make changes to this

database.

VI.Tillage: this database is used to store SWAT tillage parameters. You are given the option of modifying existing and/or adding new tillage

parameters. The typical user will not need to make changes to this

database.

VII.Urban: this database is used to store SWAT urban land type parameters.

You are given the option of modifying existing and/or adding new urban

land type parameters. The typical user will not need to make changes to

this database.

Double click on the database item to start editing.

Key Procedures

?(Optional) Edit the User Soils database

?(Optional) Edit the User Weather Stations database

?(Optional) Edit the Land Cover/Plant Growth database

?(Optional) Edit the Fertilizer database

?(Optional) Edit the Pesticide database

?(Optional) Edit the Tillage database

?(Optional) Edit the Urban database

1.1 User Soils Database Editor

The User Soils Database Editor is used to update the database storing the SWAT custom soil data: data are entered in this database when using soil maps that are not linked to STATSGO soil database included in BASINS. Detailed definitions of the variables listed under each command can be found in the Soil and Water Assessment Tool User's Manual, Version 2000see the section covering the Soil Input File (Chapter 36, Par.

36.1).

From the Edit SWAT Database dialog, double click the User Soils item (Screen 1.1.1).

Screen 1.1.1

The User Soils dialog is displayed to start the editing session (Screen 1.1.2).

Screen 1.1.2

A list of soils in the custom database is shown on the left side of the dialog. The user has three options to proceed: edit an existing soil data set, add a new soil data set, or delete a soil data set:

1.To edit an existing soil data set, click the name of the soil to be edited on

the soil list. The data for the soil will be loaded and displayed (Screen 1.1.3).

Screen 1.1.3

The data are separated in two groups: the first group of parameters are applicable to the entire soil profile and are displayed in the box titled 'By Soil'; the second group of parameters pertain to a particular soil layer and are displayed in the box titled 'By Layer'.

The layer number is displayed at the bottom of the 'By Layer' box between

the Up and Down buttons.

The different layers in the soil profile can be accessed through these buttons.

Activate the parameter text box clicking on it. Type in and/or edit the text value. You can pass to the next parameter text box pressing the TAB key. If the value of the parameter is out of range a message box like the one on screen 1.1.4, pops up.

Screen 1.1.4

Click OK: the parameter is reset to the original value or to the closest range limit.

Once all editing changes have been made, click Exit.

If changes have been made, a dialog may pop up (Screen 1.1.5).

Screen 1.1.5

This dialog reports parameters that exceed the suggested ranges. Click OK.

A dialog pops up (Screen 1.1.6).

Screen 1.1.6

Click No to return to editing and correct the values. Click Yes to continue, a new dialog pops up (Screen 1.1.7).

Screen 1.1.7

Click Yes to save the changes. Click No to proceed without saving.

2.To add a new soil data set to the database, the user has 3 options: entering

parameters on a default form, loading data from a formatted SWAT Soil input file, or copying data from an existing soil data set in the database.

a.To add a new soil using a default form, click the Add New button in

the User Soils dialog.

A modified dialog with default values for the soil profile will pop up

(Screen 1.1.8). The default values are the minimum in the respective

allowed range.

Screen 1.1.8

Click the Cancel button to exit the session.

To complete the session enter the name of the new soil and edit the

other parameters. Once finished, click the Save button to store the

new soil data set.

This returns you to the original User Soils dialog. The list of soils in the database will now include the name of the just added soil.

b.To load soil data from a formatted SWAT input file, click the Load

(.Sol) button.

A message pops up (Screen 1.1.9) warning you to use a correctly

formatted .sol file (see SWAT user Manual).

Screen 1.1.9

To quit the load operation, click No. To proceed with loading click Yes.

A browser will be displayed (Screen 1.1.10).

Screen 1.1.10

Select the soil input file (.sol) to be loaded and click OK (or double click the selection). The soil data will fill the fields in the User Soils dialog. Click the Save button to store the new data set or click Cancel to exit the adding session.

c.To add a new soil by modifying an existing soil data set, select the

name of the soil to be copied from the User Soils dialog (left side

list). Once the soil data is displayed, click the Add New (Modify)button.

A modified dialog box will appear with all the data fields filled (copied

from the previous selected soil data) except the soil name (Screen

1.1.11).

Screen 1.1.11

Enter a new soil name and modify the other data fields. Click Save to

store the modified soil data.

3.To delete a soil data set, select the name of the soil to be deleted from

the User Soils dialog (left side). Once the soil data are displayed, click

the Delete button.

A prompt box will appear asking you to verify the deletion (Screen 1.1.12).

Screen 1.1.12

Click Yes to continue with the deletion. Click No to quit without deleting. To exit the editing session of the User Soils database click Exit from the User Soils dialog.

1.2 User Weather Stations Database Editor

The User Weather Stations Database Editor is used to update the database of SWAT custom weather generator parameters: data are entered in this database for weather stations that are not in the US database included in BASINS. Detailed definitions of the variables listed under each command can be found in the Soil and Water Assessment Tool User's Manual, Version 2000see the section covering the 'Weather Input File' (Chapter 34, Par. 34.1).

From the SWAT Database Editors dialog, double click the User Weather Stations item (Screen 1.2.1).

Screen 1.2.1

The User Weather Stations dialog is displayed to start the editing session (Screen 1.2.2).

Screen 1.2.2

A list of stations in the custom database is shown on the left side of the dialog. The user has three options: edit an existing station data set, add a new station data set, or delete a station data set.

1.To edit an existing station data set, click the name of the station on the

stations list. The data for the station will be loaded and displayed (Screen

1.2.3).

Screen 1.2.3

The data are separated into two groups: the first group consists of single parameters (see top right of the dialog) while variables summarized by month are listed in the box labeled 'Monthly parameters.' The data fields for the monthly parameters can be accessed by clicking the buttons to the left of the variable names (Screen 1.2.4).

Screen 1.2.4

Activate the parameter box by clicking on it. Enter and/or edit the text value. You can move to the next parameter by pressing the TAB key. If the current value of the parameter is out of range a message box like the one on screen 1.2.5 pops up.

Screen 1.2.5

Click OK: the parameter is reset to the original value or to the closest range limit.

Once all editing changes have been made, click Exit.

If changes have been made, a prompt dialog may pop up (Screen 1.2.6).

Screen 1.2.6

A dialog pops up (Screen 1.2.7).

Screen 1.2.7

Click No to return to editing and correct the values. Click Yes to continue,

a new dialog pops up (Screen 1.2.8).

Screen 1.2.8

Click Yes to save the changes. Click No to proceed without saving.

2.To add a new station data set to the database, the user has 3 options: enter

the parameters in a default form, load the data from a formatted SWAT Soil input

file, or copy the data from an existing soil data set in the database.

a.To add a new station using a default form, click the Add New button

in the User Weather Stations dialog.

A modified dialog with default values for the soil profile will pop up

(Screen 1.2.9). The values are the minimum in the respective allowed

range.

Screen 1.2.9

Click the Cancel button to exit the session.

To complete the adding session type the name of the new station and edit

the other parameters.

Once finished, click the Save button to store the new station data

set.

This returns you to the original User Weather Stations dialog. The list

of stations in the database will now include the name of the just added

station.

b.To load stations data from a formatted SWAT input file, click the Load (.Wgn)

button.

A message pops up (Screen 1.2.10) warning you to use a correctly

formatted .wgn file (see SWAT User's Manual).

Screen 1.2.10

To quit the load operation, click No. To proceed with the loading click

Yes, a browser will be displayed (Screen 1.2.11).

Screen 1.2.11

Select the station input file (.wgn) to be loaded and click OK(or double

click the selection). The station data will fill the fields in the User