BAEN 673 Biological and Agricultural Engineering Department Texas A&M University ArcSWAT / ArcGIS 10.1 Example 2

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1 Before you Get Started BAEN 673 Biological and Agricultural Engineering Department Texas A&M University ArcSWAT / ArcGIS 10.1 Example 2 1. Open ArcCatalog Connect to folder button on tool bar navigate to C:/SWAT/ArcSWAT/Databases Ok in Catalog Tree double click the folder C:/SWAT/ArcSWAT/Databases in the Contents window double click SWAT_US_Soils.mdb. 2. Open ArcToolbox on the toolbar double click the Data Management Tools double click Projections and Transformations double click Define Projection (If ArcCatalog is crashing while opening the ArcToolbox button then instead of clicking Arctoolbox go to Search on the toolbar in the search box type Define Projection Enter it will show the Define projection tool double click on it) drag statsgo_grd from the Catalog Tree and place it into the Input Dataset or Feature Class box Click the hand icon next to the Coordinate System box select NAD_1983_Albers to highlight in the Custom folder Then press the Add to Favorites (star with a plus) button. This should have moved the projection system into the Favorites folder Cancel Cancel to exit from the Define Projection box. Note: Any tool can be opened from the search button by typing the name of the tool in the search box if the Arctoolbox button is not working or if it is making ArcMap/ArcCatalog to crash. 3. In the Contents box double click Example2 In the ArcToolbox Projections and Transformations Raster double click Project Raster drag Example2 amask to the Input Raster box click the button next to the Output Coordinate System box highlight NAD_1983_Albers Ok Ok repeat these steps for dem, and landuse to redefine the projections close all ArcCatalog windows Getting Started 1. Start ArcMap Customize Extensions check Spatial Analyst / SWAT Project Manager / SWAT Watershed Delineator ***Make sure to save your files in either the H-drive or on a flash drive*** Explanation: Create an ArcMap project file using the ArcSWAT extension of ArcGIS 10.1 that will link GIS databases with the ArcSWAT hydrologic model. Create new SWAT project / Setup working directory / Setup Geodatabases

2 1. 1. SWAT Project Setup New SWAT Project Save current document? No Project Setup dialog box appears Project Directory select folder connect to folder navigate to the flash drive Ok select the EX2 folder (***single click***) Ok SWAT Project Geodatabase change the name to EX1Output.mdb (Note: You name this file anything but it must have a.mdb extension it will go in the Project Directory) Raster Storage leave the name RasterStore.mdb (it will go in the Project Directory) SWAT Parameter Geodatabase leave the default path G:\EX2\SWAT2012.mdb Ok wait patiently Project setup is done Ok Explanation: The Project Directory is where all of the project files will be stored. Watershed Delineation (Note: You can exit the Watershed Delineation and reopen it at anytime) 1. Watershed Delineator Automatic Watershed Delineation Watershed Delineation box appears DEM Setup Click the folder icon Load from Disk Ok C:\Swat\ArcSWAT\Databases\Example2\dem_ProjectRaster Add DEM projection setup Click on the DEM Properties box appears Check the units for the Z Unit Do this by looking at the high and low values under the SourceDEM layer. For Example 2 the values are 91 to 228. Note that there are no units! Therefore, some knowledge of the actual elevations in the watershed is required. For Example 2, 100 to 228 are in meters. Therefore make sure that the Z Unit in the DEM Properties box is meters (Note: Z-units are meter by default) Ok Explanation: The Digital Elevation Model (DEM) grid is added as a GIS layer to the ArcMap project file. Focusing on the watershed of interest using a pre-prepared mask Speeds up GIS processing 2. You will define Mask manually Go back to Watershed Delineation window peg Mask Click the folder icon next to the mask box select Manually Delineate Ok click Draw Ok Draw the polygon clicking boundaries (your outlet will be located in , meters each x, y coordinates, draw the polygon including the approximate watershed area) Double-click the final vertex Apply

3 Explanation: The mask covers the watershed that you plan to simulate with a little overlap around the watershed boundaries. The mask is pre-prepared and is added as a GIS layer to the ArcMap project file. The mask is used to exclude areas outside of your selected watershed. Therefore only the data inside of the mask area are utilized in the SWAT simulation thereby speeding up computer processing time. Defining the stream network Use the threshold area method 3. Go to the Stream Definition box peg DEM-based go to the Flow direction and accumulation box and click on the icon End of DEM grid preprocessing Ok in the Area box keep the value to 500 Ha go to the Stream network box on click on the icon wait patiently End of stream preprocessing Ok Explanation: The watershed boundaries and the stream network in the watershed are calculated from the DEM using the flow direction and flow accumulation method. The locations of the subbasin outlets are also defined. A minimum, maximum and suggested subbasin areas (in hectares) can be defined. - Let s see NHD flow lines vs. SWAT stream network. You can get the NHD flow shape file from the class webpage, unzip (extract) it to your working folder Ex2 click on add data button navigate to the working folder highlight nhdflowline_ex3.shp Add Now you can compare the NHD steam lines to the ArcMap stream lines

4 (The red line is NHD flow lines and the blue line is SWAT stream network based on the DEM with a 216 ha area accumulation setting. It is pretty similar.) Defining the main watershed outlet 4. Go to the Whole watershed outlet(s) box and click on the icon use the mouse to draw a box around the watershed outlet (note: you may have to zoom-in if outlets are close-together to make sure the box is drawn around the correct outlet) 1 outlets selected (see figures below: approximately x, y coordinates are , meters on the right bottom side of ArcMap) you can double check it from the attribute table of Monitoring point Ok

5 Explanation: Selecting the watershed outlet will define the boundary of the main watershed. Delineate the watershed 5. Go to the Delineate watershed box and click on the icon Watershed delineation is done Ok Explanation: After this step the delineated watershed with all subbasins will be added as a GIS layer to the ArcMap project file. Calculate the subbasin parameters 6. Go to the calculate subbasin parameters box and click on the icon (wait patiently!) Subbasin parameter calculation successfully done Exit from the Watershed Delineation box Explanation: This function calculates basic watershed and subbasin characteristics from the DEM. A Topographic Report can be opened by going to the Watershed Delineator tab Watershed Reports Topographic Report Ok. Each subbasin is given a unique ID number.

6 Defining the Land Use 1. HRU Analysis Land Use / Soils / Slope Definition Land Use Data tab the Land Use Grid box and click on the open file folder icon peg Load Land Use dataset(s) from disk Open Is the grid or shapefile projected? Yes go to C:\ Swat\ArcSWAT\Databases\Example2 highlight the landuse_rasterproject file you may get this message- All geometries involved in this operation must have the same spatial reference.) If you have this problem then there are two ways to define it. If this error message did not come up then skip the next two paragraphs. 1) open the ArcCatalog find the directory (C:\Swat\ArcSWAT\Databases\Example3\landuse) right click on properties edit the spatial reference peg Define a coordinate system for my data to match existing data Next select the dem file (C:\ Swat\ArcSWAT\Databases\Example3\dem) for the dataset ) open Next Finish back to Raster Dataset Properties window Apply Ok 2) click the ArcToolBox Data Management Tools Projections and Transformations define Projection input dataset or feature class is the landuse file(c:\swat\arcswat\databases\example3\landuse) click the icon of coordinate system XY coordinate System tab import select the dem file (C:\Swat\ArcSWAT\Databases\Example3\dem) Add Apply Ok Ok go to the Choose Grid Field box and from the drop-down menu select Value Ok LookUp Table User Table OK highlight the lunlcd.dbf file Select Reclassify Explanation: The landuse dataset is added as a GIS layer to the ArcMap project file. The SWAT LandUse Classification Table will be created automatically (see Figure below). However, in order to fill the 3 rd column (LandUse SWAT) a look-up table (in.txt or.dbf format) can be imported or the 3 rd column can be manually entered. The look-up table converts the GIS landuse classification to a classification code recognized by the SWAT model (RNGE, PAST, URBN, etc).

7 Defining the Soil Types 1. Click the Soil Data tab go to the Soils Grid box and click on the open file folder icon peg Load ArcSWAT US STATSGO from disk Reclassify Ok Explanation: The soils dataset is added as a GIS layer to the ArcMap project file. The SWAT Soil Classification Table will be created automatically (see Figure below). However, in order to fill the 3 rd column (Stmuid = STATSGO (State Soil Geographic database) polygon number, dominate soil phase) a look-up table (in.txt or.dbf format) can be imported or the 3 rd column can be manually entered. The look-up table converts the GIS landuse classification to a classification code recognized by the SWAT model. The soil map grid must be linked to the U.S. soils database that is provided with the ArcGIS interface or to a customized User Soils database. Defining Slopes

8 1. Click the Slope tab peg Multiple Slope go to the Number of Slope Classes box and in the drop-down menu select 3 go to the Current Slope Class box and in the drop-down menu select 1 go to the Class Upper Limit (%) box and type-in 0.6 Add go to the Current Slope Class box and in the drop-down menu select 2 go to the Class Upper Limit (%) box and type-in 1.5 Add Reclassify Ok Overlay Ok Explanation: The slope of each subbasin is taken into account to determine the areas of each Hydrologic Response Unit (HRU). The Overlay command adds the landuse, soil and slope layers to the ArcMap project file. A report on landuse, siol and slope distribution can be found by going to HRU Analysis tab HRU Analysis Report. Hydrologic Response Unit (HRU) Definition 1. HRU Analysis HRU Definition HRU Thresholds peg Multiple HRUs go to the Land use percentage (%) over subbasin area box and type-in 10% go to the Soil class percentage (%) over land use area box and type-in 10% go to the Slope class percentage (%) over soil area box and type-in 10% Create HRUs Ok Explanation: The distribution of HRUs within each subbasin is calculated based on the landuse, soil and slope layers. The interface allows the user to specify criteria for landuse, soil and slope to be used in determining the HRU distribution. One on more unique landuse, soil and slope combinations can be created for each subbasin. Runoff is simulated separately for each HRU and routed to the stream channel in the subbasin. Input the Weather Data 1. Write Input Tables tab Weather Stations Weather Generator Data tab From the Locations Table dropdown box select WGEN_user Ok go to the Rainfall Data tab peg Raingages go to the Precip Timestep box and in the drop-down menu select Daily go to the Locations Table box and click on the open files folder icon highlight the file pcpfork.txt go to the Temperature Data tab peg Climate Stations go to the Locations Table box and click on the open file folder icon highlight the file tmpfork.txt Ok Ok Exit from the Weather Stations window Generate SWAT Input Files 1. Write Input Tables tab Write SWAT Input Tables Select All Create Tables Yes Ok Exit from the Write SWAT Input Tables window

9 Explanation: Many of the input data files required by the SWAT model are generated by this step. ***If the.wgn file is not being written properly an error message will prevent you from continuing this step. In order to fix this issue you must go to the folder where you are saving your files. Double click SWAT 2012 to open the Access software. Go to the wgnrng and locate the PR_W1 and PR_W2 fields in the CRNAME column. Add an underscore to the end of both of these fields (So it should be PR_W1_ and PR_W2_ ). Save the file, close Access and rerun the Write SWAT Input Tables. Edit SWAT Input (Optional) 1. Edit SWAT Input tab click Subbasins Data 1) Edit Subbasin Inputs SWAT Input Table select soils (.Sol) go to Subbasin select 1 go to land use select PAST go to Soils select TX212 go to slope select click ok click Edit values you can modify values here, but we will not change any value. exit cancel Setup SWAT Simulation 1. SWAT Simulation tab Run SWAT Start Date: 1/1/1977 Ending Date: 12/31/1978 go to the Printout Settings box and peg Monthly Setup SWAT Run Ok Run SWAT Ok Fini!!!

10 Explanation: The dates of the SWAT simulation and the printout frequency is specified in this step. More SWAT input data files (CIO, COD, PCP.PCP and TMP.TMP) are generated at this time. The Run SWAT command runs the SWAT executable file. Optional; you can save current simulation as sim0.