By: Emma Beck and Deborah Berry
The goal for the Disappearing DC summer project was to map all the buildings demolished in DC. This will provide data for companies, nonprofits, and the City of DC to analyze. This data will show how the city is growing and in what direction. Our hope was to map the buildings in DC since its creation in 1790 when the land was set aside for the purpose of a capital city. This is clearly a large task and requires lots of time.
Our plan to achieve our goal is to take old maps of Washington DC and trace over them using ArcGIS. We decided to start with Sanborn maps from 1903. There were many reasons for this choice. We wanted to start with maps that were not too recent, and the maps from 1903 were out of copyright, so digital versions of the maps are available from the Library of Congress’s website, making it accessible and easy to download. The Sanborn maps from 1903 were also very detailed and could provide us with a large number of buildings. The Library of Congress has done a phenomenal job of uploading these maps so their resolution is good and easy to trace in ArcGIS. These maps were reproduced every few years so we knew that there were maps a few years later we can compare them to. Brian Kraft has looked through historic building records and has created a database which has a lot of information. He has also created a shapefile that has most of the buildings currently in DC and their history.
First we went to the Library of Congress’s website. There we searched for Sanborn maps of Washington DC. We downloaded the TIFF file for the square we needed. We brought the TIF file into ArcGIS where we used DC Street Centerlines to georeference the sections of the map. Once the maps were georeferenced, we used the extinct buildings layer in editor mode to outline the buildings that appeared on the map. If the building is still present, we would not map it. We found that many of the squares would not line up properly with the buildings that are still or currently there, which we figured out by referencing the Histoic_DC_Buildings Layer. We then further georeferenced that square so that it would be more accurate before tracing. After they were traced, we added the addresses into the attribute table. This file would be used later to join with a spreadsheet of data we acquired from Brian Kraft. In order for the join to work, we had to put two spaces between the street number and the street name. If there were any building names, we wrote that in “building name” or “notes” fields. Brian Kraft collected his data by looking at old building permits. His data includes the date that the permit was issued, the lot, square, owner, builder, and use. While Brian was able to collect data for a large number of buildings, there are still some buildings that were on the Sanborn maps but were not in Brain’s data.
We were able to map almost all of NW Washington DC as it stood in 1903, totalling in over 8,000 buildings. We were supposed to receive students through the city of Washington DC. Due to unforeseen circumstances we were only had one student for about a week. Fortunately we had a few other volunteers but with the lower numbers, we had less progress than anticipated.
-finish GW section to show (goal at this point)
-try to map as many buildings as we can from the history of DC without worrying about the dates they were built. Assume dates from missing chunks
-make the info accessible, and focus on trying to collect more data for the buildings already mapped, because only a third have information that Brian Kraft collected
Some challenges we have faced and will continue to encounter are finding the dates these buildings were built. Because the Sanborn maps are hand drawn, it will create a challenge to try to aline the different maps. Like mentioned above, the 1903 maps are out of copyright. As we progress closer to the present, it will be a challenge to find maps in the public domain that are online. Being based in Washington DC while doing this project has gives us access to many resources that collect maps of the area. We were fortunate enough to look at maps in the Library of Congress Map and Geography library. We will be able to use the physical maps that they have stored later. It will be difficult however to trace them on ArcGIS because they are not online. If we were to scan them in the library, the scans would not have high resolutions because they are enclosed to protect the maps. This would show up as a reflection during scanning. Despite these challenges, this is a project that should continue to be worked on and perused. Some of the building have the same addresses in multiple years, so they are given the wrong dates when joined with the spreadsheet. There are some buildings that have a permit but don’t appear on that map for the year (e.g.: building permit says 1887, but it doesn’t appear on the 1888 map, but does on the 1903 map)
Thank you very much to George Washington Geography department for allowing us to use their resources for the summer. Thank you also to the Library of Congress, Washington DC Historical Society, and Rosemary at National Geographic for giving tours to our team this summer!
ExtictBldgs – the layer we edit and draw the buildings onto. Each person had one in their own folder, file, and a row to work on
BldgsPoly – current buildings in Washington DC, but has little information about them
Historic_Data_on_DC_Buildings – Brian Kraft’s layer of data that has most of the current buildings in Washington DC and information about their use, date built etc
GW Campus Boundary – The outline of area GW owns
GW Current Buildings – Buildings that are currently in GW, clipped from BldgsPoly layer
ExtictBuildings_Merge 3 – All of the work that we have done so far this summer combined into a single layer
1888_GW_Buildings – shows all the buildings on the GW campus in 1888
Sources for the Maps:
Library of Congress-Sanborn Maps. Library of Congress also has more physical maps that are not online due to copyright or just haven’t been scanned yet
http://digdc.dclibrary.org/ – has Real Estate maps from earlier that can also be used