Introduction
Welcome to Digital Mapping Ecosystems! This workshop is both an introduction to critical cartography practices and a hands-on tutorial that will guide you throught the process of creating and sharing a digital mapping project. This site provides complete documentation for the workshop.
This workshop is a work in progress and the site will be updated accordingly.
Goals
This workshop aims to facilitate a conversation between participants about how we can best engage and support researchers who are intereseted in creating and using digital maps in their work in some way. In some cases researchers want to explore materials in a spatially oriented research environment that enables them to ask questions about people and places. Other researchers may also want to share these results and make them accessible online to different communities. Beyond which tools can help researchers accomplish these goals it is also important to engage with them about all aspects of this process, from data management to thinking about the ethics of which platforms they use and how they visualize their data.
Through this workshop we will not only build skills and competencies that will help to support this type of scholarship but we will also help to become part of a community of practice that emphasizes a critical approach to mapping and cartography.
Setup
We will be using 3 different tools during this workshop - CARTO, MapBox, and GitHub. In the past few years most mapping platforms have either moved towards a subscription model or made it more difficult to use their platforms freely. Platforms, such as ArcGIS Online or Google My Maps, while free tend to become problematic with respect to how they store data and provide access to it. Another great option that we will not be utilizing in this workshop and that could easily replace CARTO is Tableau.
CARTO - Carto is free for students and researchers. After you create a CARTO account you will be able to apply for an ambassador or a researcher account. For those who already have projects in CARTO you can make the request to become an ambassador or researcher. For new users to CARTO after this workshop you will be able to point to this project as an example of your work. Researchers or Ambassadors get special CARTO accounts with features and larger data storage. According to CARTO “to qualify, you must be an individual working on non-commercial projects and having a considerable impact in your community.”
Carto Ambassador and Researcher Accounts
Student Developer Pack via GitHub provides access to free CARTO account
MapBox - Limited free account for everyone. For research purposes it will likely be more than enough for almost any project.
GitHub - Free for everyone. Some limits on file size uploads. Anything you publish is publically accessible by others.
What makes a good project?
What makes for a good project?
Good projects are meaningful and impactful. They make you stop and ask questions. A digital project provides a way to directly communicate that meaning and impact.
Two model projects that have helped to inform this workshop are South Carolina’s Green Book project and the Digital Scholarship Lab at the University of Richmond American Panorama project:
These two projects take existing archival materials, process them so they can be made accessible online, and do so in a seamless way so that individuals can interact, learn, and ask questions through them.
We will use these projects as starting points and attempt to recreate them on a local level.
For this example project we want to learn more about the history of Los Angeles through the lens of the GreenBook. We will use data that will create points for where Greenbook establishments existed, boundaries from the Homeowner’s Loan Corporation, current neigbhorhood boundaries, and an image overlay of historical maps including the HOLC map. This data provides a great introduction to different types of geospatial data and important geospatial processes including geocoding, georeferencing, and spatial joins.
Through these datasets we will create a digital project that will let us explore Los Angeles and provide opportunities for meaningful engagement, interpretation, discovery, and critical thinking. Moreover, the project is replicable and can be adapted to other cities and communities.
Data
During this workshop we will use different types of data files, including CSV, Geojson, ESRI Shapefiles, and Geotiffs that will help us to work with different types of geospatial features including points, polygons, and raster images.
You will get a basic understanding of these types of different data, specifically how they are created, how they can be mapped, and how they can interact with one another.
Smaller files have been placed in a GitHub repo. Larger Geotiffs (historical maps) have been placed in a Google Drive.
CSV
CSV files are your friends. They can be used in virtually every type of tool or software. For mapping purposes they only need to contain two types of information in order to be used:
- Latitude and Longitude coordinates allow an individual record to be located on a map as a point. Latitude and Longitude can be generated through the process of geocoding. Geocoding can be an automated process if your CSV records have known addresses. If not, you can manually add latitude and longitude. For historical research the process can often times be both automated and then manually checked to ensure that the locations are accurate.
- You do not need to have latitude and longitude data in a CSV file in order to visualize data on a map. If you have a column that contains geographic information, for example a census tract or a neighborhood, and you also have a corresponding data layer of that census tract or neighborhood then you can join your CSV file to that other file and visualize your data within the stated boundary.
CSV files with locations of places listed in the GreenBook. Special thanks to Professor Genevieve Carpio at UCLA and student research assistant Jose Cardona for creating and sharing the data. Jose Cardona compiled the data for these two CSV files. We used google sheets to store the data and a script that plugs into google sheets to geocode the addresses. Each address was manually transcribed by Jose from the NYPL GreenBook website - https://digitalcollections.nypl.org/collections/the-green-book#/?tab=about - then checked against current street data to verify each location.
CSV files that we will be using:
- Greenbook1939
- Greenbook1947
Geojson
Geojson are also your friend! Geojson is an open standard that displays different types of features. For this workshop we will be working with polygon boundaries in order to show neighborhoods and other distinct geographic areas. The HOLC_LosAngeles.geojson files is a geojson file which is a geographic encoding format.
Geojson files that we will be using:
- HOLC_LosAngeles This file was downloaded from the American Panorama project. This project provides access to original scan maps of the Homeowner’s Loan Corporation, georeferenced maps, and area descriptions with polygons.
- la-county-neighborhoods-v6 This file was downloaded from the LATimes Mapping LA Boundaries API.
ESRI Shapefile
ESRI Shapefiles are a propreity format that primarily work with ArcGIS but can also be used in different software including QGIS and CARTO. For this workshop we will work with one ESRI Shapefile in order to see the difference between it and an Geojson file. The biggest difference being that a shapefile is comprised of multiple files instead of just one file. This poses some challenges and The la_county-neigbhorhoods-v6.zip file contains a shapefile, which is a vector data format developed by ESRI. The shapefile format requires specialized software to be opened. CARTO allows for shapefiles (up to a certain size) to be uploaded as long as they are zipped.
ESRI Shapefile that is provided:
- la-county-neighborhoods-v6_shapefile This file was downloaded from the LATimes Mapping LA Boundaries API. It was renamed to indicate that is a shapefile. In order to be used in CARTO the zipped file must be uploaded. In order to be used in ArcGIS or QGIS you unzip the folder and open the .shp file.
Geotiffs
Geotiffs are amazing, espeically for humanities oriented spatial research. A geotiff is an image file that has been georeferenced using GIS software such as ArcGIS or QGIS. Georeferencing or georectifying an image means that the image has had control points assigned to it so that it can be placed into a specific geographic location by software, such as MapBox. We will be working with Geotiffs and we will not be georeferencing any images.
Geotiffs are usually larger files and because of this you will need to access them via a Google Drive.
Geotiffs:
- HOLCCentralLA This was downloaded from the American Panorama project.
- Watts1965 This map was downloaded as part of a MaptimeLA workshop that was inspired by this LA Times story, Inside the Watts Curfew Zone.
Resources:
Carto
CARTO has been chosen for this workshop as an example of a simple exploratory mapping platform. What I mean by this is that many researchers do not need the full functionality and performance of desktop mapping software like ArcGIS or QGIS. They need a fast and intuitive platform in order to see data or perhaps do simple analysis. CARTO is probably the best platform available to quickly introduce students to the essentials of web mapping.
A slide deck has been created that provides a step-by-step tutorial and walkthrough of how to piece together the example map. It is broken up into different sections. The CARTO section walks you through adding several layers of data. The deck then pauses and sends you to the Mapbox section where you create a tileset of historical map. Once this is completed you go back to CARTO and eventually add it as a base layer.
Mapbox
Mapbox is an open source platform that allows you to design custom maps. If CARTO is an entry level tool for easily creating a fully interactive map in a few minutes, Mapbox is on the other spectrum. You can create fully customizable maps fairly quickly but to make them fully interactive (pop-up windows or widgets etc) it takes time. Mapbox also does not provide access to any spatial tools in its interface. This doesn’t mean that you cannot make those types of maps. It just means you will need to learn how to code those yourself.
The other thing that Mapbox lets you do and the reason why it is a part of this workshop is that you can utilize it as a server to host your own historical map layers (or even image layers).
We will upload a Geotiff to Mapbox as a tileset, add that tileset to an existing style (really just adding them to a base layer of data, imagine if you opened up Google Maps and you saw a historical map in addition to the current satellite data!).
Mapbox is already fully integrated into platforms such as CARTO and Tableau. What that means is that once you create your style with a historical map you can add it to these platforms with just a simple click of the button.
We won’t stop there though. There are some limitations to this and as part of this workshop we will use MapBox and our data to try and recreate our CARTO maps (in part) as stand alone coded maps. This means we will take our data out of CARTO, put it into Mapbox, and then write (really copy) some code.
Github
GitHub is the final piece of this workshop. GitHub is not necessarily a mapping platform. There is support through Jekyll for making map posts and there are a few great examples of how to make limited, but very interactive maps.
For this workshop though GitHub is more about creating a space to help you manage a project and share it.
This GitHub model is meant to be an exploratory one. This is NOT about long term preservation and access. It is better than many other short term fixes though and it provides a solid basis for thinking about taking a project to the next level. That said some organizations and individuals have used GitHub for providing access to select data, project work, and other materials.
For this workshop I have created a GitHub repository that has some data as well as some sample html. Using GitHub you can publish this html code and create different maps.
Everyone will fork this GitHub repoository and be able to adapt and use it for their own purposes.