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1. Click the Catalog tab.
2. Right-click the HydrologyLab geodatabase and selectNew > Feature Class….
3. For ‘Feature Class Name’, type “Outlet”.
4. Use the ‘Geometry Type’ drop-down menu to select Point.
5. For Coordinate System, select Current Map.
6. Click Run.
7. On the Standard toolbar, click the Edit tab and click the Create button.
   
   
8. 
   
   
9. On the Create Features pane, select Outlet layer and click Point. Click ->.
   
   
   
   
10. In the Map Display, click the outlet pixel to draw a point there.
    
    
    
    
11. On the Editor toolbar, click Save.
12. When asked if you want to save your edits, click Yes.
13. Close the Editor toolbar and the Create Features tab.

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1. Click Tools from Analysis tab.
2. In the Hydrology toolset, double-click the Watershed tool.
3. For ‘Input flow direction raster’, select the FDR layer.
4. For ‘Input raster or feature pour point data’ select the Outlet layer from the drop-down menu.
5. For ‘Output raster’, rename the raster from “Watersh_FDR1” to “Watershed”.
6. Ensure your Geoprocessing pane appears as shown below and click Run.
   
   

...

Notice that this is very close, but does not exactly match the boundaries of the subbasin you were originally provided from NHDPlus.

1. In the Contents pane, turn off all layers beneath the Watershed layer, so that only the cells within the newly defined subbasin are visible.

Delineating streams

Now that you have delineated the subbasin boundaries, you will generate flowlines. The number of flowlines that are generated will depend upon the flow accumulation threshold you select in separating a flowline cell from a non-flowline cell. For the purposes of this lab, you will select a threshold of 3000.

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1. Click Tools from Analysis tab.
2. In the Hydrology toolset, double-click the Stream Link tool.
3. For ‘Input stream raster’, select the Streams layer.
4. For ‘Input flow direction raster’, select the FDR layer.
5. For ‘Output raster’, rename “StreamL_Stre1” to “StreamLinks”.
6. Ensure your Geoprocessing pane appears as shown below and click Run.
   
   
   
   
7. Symbolize the StreamLinks layer using unique values.
8. In the Contents pane, collapse the StreamLinks symbology.

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1. Click Tools from Analysis tab.
2. In the Hydrology toolset, double-click the Watershed tool.
3. For ‘Input D8 flow direction raster’, select the FDR layer.
4. For ‘Input raster or feature pour point data’ select the StreamLinks layer.
5. For ‘Output raster’, rename “Watersh_FDR2” to “Catchments”.
6. Ensure your Geoprocessing pane appears as shown below and click Run.
   
   
   
   
7. Symbolize the Catchments layer using unique values.
   
   
   
   
8. In the Contents pane, collapse the Catchments symbology.

...

1. Click Tools from Analysis tab.
2. Double-click the Conversion Tools toolbox à From Raster toolset à Raster to Polygon tool.
3. For ‘Input raster’, select the Catchments layer.
4. For ‘Output polyline features’, rename “RatsterT_Catchme1” to “CatchmentPoly”.
5. Uncheck Simplify polylines.
6. Ensure your Geoprocessing pane appears as shown below and click Run.
   
   
   
   
7. Symbolize the CatchmentPoly layer using unique values with ID as the value field.
   
   
   
   
8. In the Contents pane, collapse the CatchmentPoly symbology.

...

1. Click Tools from Analysis tab.
2. Collapse the Conversion Tools toolbox.
3. In the Hydrology toolset, double-click the Stream to Feature tool.
4. For ‘Input stream raster’, select the StreamLinks layer.
5. For ‘Input flow direction raster’, select the FDR layer.
6. For ‘Output polyline features’, rename the feature class from “StreamT_StreamL1” to “DrainageLines”.
7. UncheckSimplify polylines.
8. Ensure your Geoprocessing pane appears as shown below and click Run.
   
   

Calculating Strahler stream order

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1. Click Tools from Analysis tab.
2. In the Hydrology toolset, double-click the Stream Order tool.
3. For ‘Input stream raster’, select the Streams layer.
4. For ‘Input flow direction raster’, select the FDR layer.
5. For ‘Output raster’, rename the raster from “StreamO_Stre1” to “StrahlerOrder”.
6. Ensure your Geoprocessing pane appears as shown below and click Run.
   
   
   
   
7. In the Contents pane, turn off all layers except for the new StrahlerOrder layer, so that its symbology is more apparent.
   
   

...

1. Open the DrainageLines attribute table.
2. At the top of the DrainageLines attribute table, click the Add Field button.
3. 
4. For ‘Name:’, type “StrahlerOrder”.
5. Use the ‘Type:’ drop-down menu to select Short Integer.
6. Ensure your ‘Add Field’ window appears as shown below and click Save on top of  the main tab.
   
   
   

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Scroll all the way to the right and notice the new StrahlerOrder field has been added to the end of the table. All of the values are currently null, but will later be populated with the Strahler Order integers from the OrderTable.

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1. Click the Table Options button and select Joins and Relates > Add Join….
   
   
   
   
2. For ‘Input Join Field’, select the grid_code field.
3. For ‘Join Table’, select the OrderTable table.
4. For ‘Output Join Field’, select the VALUE field.
5. Ensure that your Geoprocessing pane appears as shown below and click Run.
   
   
   
   
6. Scroll across the table and notice that most of the statistics (Min, Max, Mean, Majority, Minority, Median) are the same and all contain the Strahler order integer, so it doesn’t matter which field you copy, though you will choose the MIN field for this lab.
7. In the attribute table, right-click on the StrahlerOrder field header and select Calculate Field….
8. Scroll down the list of ‘Fields:’ and double-click the OrderTable.MINORITY field and click Run.
9. Scroll down the newly populated StrahlerOrder field and notice the values of 1, 2, and 3 corresponding to Strahler order value. You no longer need join.
10. Again, click the Table Options button and select Joins and Relates > Remove Join(s) > Remove All Joins.
11. Symbolize the DrainageLines layer using graduated symbols based on the StrahlerOrder field.
12. In the Contents pane, turn on only the Outlet, DrainageLines, and CatchmentPoly, layers and turn off all other layers.
    

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Create an 8.5 x 11 layout showing the vector catchment basins along with the stream links symbolized using graduated symbols according to their Strahler order and the outlet point that you used.

1. An exported map of DEMRecon layer turned on.
2. Create an 8.5 x 11 layout showing the vector catchment basins along with the stream links symbolized using graduated symbols according to their Strahler order and the outlet point that you used.