Urban Features#
Required Data
File |
Content |
---|---|
*.shp |
Building Polygons |
Data Location: \Coastal Training\Project Data\Buildings
Step 1: Load buildings#
Click the Project Data Group.
Drag the Building Polygons shapefile onto the map space.
![../../_images/bldg001.png](../../_images/bldg001.png)
The Building shapefile requires 3 Attributes.
Collapse field; 0 = no collapse, 1 = collapse; (see Data Input Manual)
ARF field; 1 = assign area reduction
WRF field; 0 = no width reduction, 1 = assign width reduction
Step 2: Prepare the map#
Uncheck the Grid layer.
Uncheck the Elevation layer.
Check the Google image.
Uncheck the Outfalls, Inlet Junctions, and Conduits in the User Layers group.
Step 3: Digitize missing buildings#
Click the Building Polygon layer.
Right click the layer and click the Edit Pencil.
![../../_images/bldg006.png](../../_images/bldg006.png)
Zoom in to the lower east side of the grid.
![../../_images/bldg005.png](../../_images/bldg005.png)
Right click the top of QGIS near the Tool Bars and Click the Shape Digitizing Toolbar.
![../../_images/bldg007.png](../../_images/bldg007.png)
Click the Add Rectangle button.
![../../_images/bldg008.png](../../_images/bldg008.png)
Center the map on the missing buildings and use the cursor to cover them with a polygon.
Left click one corner of the building.
Move the cursor to the opposite corner and right click to close the polygon.
Fill the 3 required attributes and click OK. 0 collapse, 1 ARF, 0 WRF
![../../_images/addbldg.gif](../../_images/addbldg.gif)
To digitize a building that is disoriented, use the 3 Point option.
![../../_images/bldg009.png](../../_images/bldg009.png)
Click one corner of the building.
Click the adjacent corner.
Move the cursor to the opposite side of the building and right click to close the polygon.
![../../_images/addbldg2.gif](../../_images/addbldg2.gif)
To digitize a non-rectangular structure, use the regular Add Polygon button.
![../../_images/bldg010.png](../../_images/bldg010.png)
![../../_images/addbldg3.gif](../../_images/addbldg3.gif)
It is faster to digitize all buildings and then fill in the missing data using the Attributes Table.
![../../_images/bldg013.png](../../_images/bldg013.png)
Make a mistake?
Delete key will delete the last vertex.
ESC key will delete the current polygon.
CTRL-Z will undo the last completed task.
Leave a buffer between any building and the edge of the grid.
Covered parking structures and pools do to change the flow direction or displace volume.
![../../_images/bldg011.png](../../_images/bldg011.png)
Sort the buildings by FEAT_TYPE. Select the GARAGE and POOL features using the line numbers. Delete them.
![../../_images/bldg012.png](../../_images/bldg012.png)
Step 3: Assign buildings#
Collapse the widgets and select the Grid Tools.
Click the Evaluate Reduction Factors (ARF and WRF) button.
![../../_images/bldg002.png](../../_images/bldg002.png)
Set up the parameters and click OK
![../../_images/bldg003.png](../../_images/bldg003.png)
Close OK the window.
![../../_images/bldg004.png](../../_images/bldg004.png)