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Urban Features

Urban Features#

Required Data

File

Content

*.shp

Building Polygons

Data Location: \Coastal Training\Project Data\Buildings

Step 1: Load buildings#

  1. Click the Project Data Group.

  2. Drag the Building Polygons shapefile onto the map space.

../_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#

  1. Uncheck the Grid layer.

  2. Uncheck the Elevation layer.

  3. Check the Google image.

  4. Uncheck the Outfalls, Inlet Junctions, and Conduits in the User Layers group.

Step 3: Digitize in empty missing polygons#

  1. Click the Building Polygon layer.

  2. Right click the layer and click the Edit Pencil.

../_images/bldg006.png

  1. Zoom in to the lower east side of the grid.

../_images/bldg005.png

  1. Right click the top of QGIS near the Tool Bars and Click the Shape Digitizing Toolbar.

../_images/bldg007.png

  1. Click the Add Rectangle button.

../_images/bldg008.png

  1. 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

  1. To digitize a building that is disoriented, use the 3 Point option.

../_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

  1. To digitize a non-rectangular structure, use the regular Add Polygon button.

../_images/bldg010.png ../_images/addbldg3.gif

  1. It is faster to digitize all buildings and then fill in the missing data using the Attributes Table.

../_images/bldg013.png

  1. 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.

  1. Leave a buffer between any building and the edge of the grid.

  2. Covered parking structures and pools do to change the flow direction or displace volume.

../_images/bldg011.png

  1. Sort the buildings by FEAT_TYPE. Select the GARAGE and POOL features using the line numbers. Delete them.

../_images/bldg012.png

Step 3: Assign buildings#

  1. Collapse the widgets and select the Grid Tools.

  2. Click the Evaluate Reduction Factors (ARF and WRF) button.

../_images/bldg002.png

  1. Set up the parameters and click OK

../_images/bldg003.png

  1. Close OK the window.

../_images/bldg004.png
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