Shapefiles

Manipulating Shape Files

Extracting a subset of shape files

Why: too big to load into OCAD - eg all the buildings in Boston or Massachusetts

Example: Cambridge

Get LIDAR data

• https://coast.noaa.gov/dataviewer/

• Click on Elevation/Lidar

• Select area around Harvard indluding the area S of the river and Radcliffe. This might be too big for my computer to handle

• Click on the cart for 2021 USGS Lidar: Central Eastern MA

• Go to the cart

• Click on Next

• Fill in the information. Name: Harvard 2025. Projection: UTM. Vertical Units: Meters. Output: Point. Data classes: all. Next

• Fill in email (president@navigationgames.org)

• Check the results and submit. Order number is 903506.

• Use 1:4000. Change name of the map to put it in the right place. Calling it "NG Harvard.ocd". Next.

• Zoom in to where the map is to be; Check "Rotate map to magnetic north" and use the provided angle.

Start the map in OCAD

• File > New Map Wizard

• Worldwide / ISSprOM 2019; check Import OSM data. Doublecheck that the coordinate system is UTM something. Next.

• When it is ready, save the file as NG Harvard OSM.ocd

• Re-open "NG Harvard.ocd"; select everything and delete. Then bring in "NG Harvard OSM.ocd" as a background map.

Get shapefiles

• https://www.cambridgema.gov/GIS/gisdata From here you can get to their data dictionary, from which you can download data layer by layer.

  • Buildings

Bring in shapefiles

1. Open NG Harvard Blank map in OOM.

2. File > Import the shapefile. You'll have to assign the symbol.

3. Edit to remove the objects outside of the drawing area. Select symbols, then invert selection (easiest approach), then delete.

4. Save as OCAD 12 file with an appropriate name.

5. Import into the OCAD file, in OCAD.

OCAD

Importing into OCAD is hard because https://www.ocad.com/wiki/ocad/en/index.php?title=Import_Files#Import_Shape_Files does not match what I see when I do File > Import.

• (Buildings) File > Import. Select the shapefile and leave everything else default. Wait for a long time. 

• Map > Convert imported layers to symbols -- I futzed with this and was not successful. Giving up again; going back to OOM for this.

OOM

• Open Map: NG Harvard test.

Get imagery from MassMapper

• Go to the website and hit "Enter"

• Zoom into Harvard.

• Use the i with red outline button to put an outline around the areas we want to map.

• Pop up has 2023 Aerial Imagery Index; there are 4; click on each to download.

  • 19TCG240920

  • 19TCG255920

  • 19TCG240935

  • 19TCG255935

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Example: Boston

Available Shape Files

Source: google "Boston shape files"; examine the top 2 pages of results in google.

• https://bostonopendata-boston.opendata.arcgis.com/

• https://data.boston.gov/

  • Geospatial. For these, look for the "landing page" and from there you can view on map.

    • treekeeper street trees - used

    • treekeeper park trees - not used (redundant)

    • sidewalk inventory (2014) - view on map - used.

    • sidewalk centerline

    • public schools

    • public libraries

    • pedestrian ramp inventory (2014, modified 4/20/25). Viewing these on the provided map, they don't look right. They just look like point features. not using.

    • park features - not useful - point features with tet

    • open space - not super useful imho

    • non public schools

    • hydrography (polygon)

    • hydrography (line)

    • hospitals

    • fire hydrants

    • colleges and universities

    • city of boston outline bondary (water included)

    • city of boston outline boundary (water excluded) - this might be good for the edge of the water.... for contour line at 0....

    • Boston buildings with roof breaks

    • blue bike stations

    • parcels - might be useful for getting owner contact info

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Importing into OCAD

Generally I am finding that importing directly into OCAD is hard. A challenge is including the right auxiliary file that maps imported objects into symbols, or (after import) mapping objects to symbols. Importing into OOM seems to work more easily. 

Method:

1. export shapefiles from koordinates.com - eg street edges

2. Import into OOM.

3. Save as ocad file

4. Import into OCAD file.

5. All the imported items are selected; go to the symbol we want (edge of pavement), and change symbol to that.

Source:

• koordinates.com https://koordinates.com/layer/112612-boston-sidewalks/

  • I created an account there, with president@ng email address.

Buildings

https://massgis.maps.arcgis.com/apps/View/index.html?appid=1b933ed4332345e7a6cffd36475743bf

This instructs me to click on a city then in the popup to download data. Extracted into Shapefiles / Structures massgis/

Import in OOM. Huge amount of data so takes a while. Then use the cutout tool to draw a rectangle and cutout anything outside of that rectangle. Save as ocad file and import. This worked successfully, and I added the buildings into my OCAD file. 

Coastline: I got the shape file but importing into OOM didn't let me see Boston - it was elsewhere?

Trees: park trees seem to load fine. There are so many street trees that it takes a long time to load anything. I gave up for now.

Extracting subset of trees using QGIS

1. Project > New

2. Import shape files for the streetkeeper trees by dragging the file into the Layers pane (bottom left).

3. Use selection (awkward - the mouse clicked in a different place than it showed but I managed nonetheless) to select the north end trees. 

4. Export or save: right click on the layer: Treekeper_Street_Trees and export selected into a new shapefile. Watch where you save it (3 dots in the popup menu)

5. Open OOM (base map for north end) and import using the bush or small tree symbol. Further trim the selection and save as OCAD file.

6. Import the OCAD file in OCAD.

7. Create a new tree symbol just for those trees, and move them over to that symbol. Save as "North End 3 - Strees buildings trees" or something like that.

Extracting coastline using QGIS

1. ...

2. Use split features. Draw a line across the line (left click for first one, then right click for second one to end it), and again at the other end. There is no indication that the line is split, but when you go to select it you can see...

3. ...

4. Turns out the coastline was not accurate enough at the North End to keep it.

Other features we want to bring in

• Park trees: Not bringing in the park trees bc the streetkeeper trees seem to include those.

• Coastline: Not bringing in the coastline bc not sufficiently accurate.

• Street inventory: these are 2D shapes not lines. I opened the shape file from https://data.boston.gov/dataset/sidewalk-inventory into OOM. I selected and deleted shapes outside of the North End. Then save as ocad file. Then import into OCAD. Select all (by symbol) and change to new symbol duplicated from the paved area with boundary line (upper). Looks great. Saved as North End 4 - added sidewalks.ocd

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