Tag Archives: QGIS

CHM Lab Exercises Updated!

One of the most valuable resources for Community Health Mappers remains the series of lab exercises created two years ago. Our workshops, while effective, are short and only scratch the surface of what you can do with mapping tools. They are basically a quick start guide to Community Health Mapping. The labs however, can be used as a resource to help you build your skills once you’ve taken the first steps towards mapping your community.

The technology changes rapidly. QGIS produces a new stable version every 4 months. Annually QGIS also produces a long-term release. Carto and Fulcrum also update their tools on a regular basis. This mean the lab exercises need to be updated to keep pace.

The good news is that this spring the labs were all updated and expanded. There is some foundational knowledge needed to really take the next step after a workshop. The current revised set of labs includes Lab 0: A Community Health Map Introduction and Reference. This lab has background on the Community Health Maps project and the workflow. It also contains a Glossary of GIS terms, and several appendices covering: A) available software, B) data sources and C) everything you need to know to better understand coordinate systems and projection.

The remaining labs are as follows:

Lab 1 covers field data collection and has been updated to work with Fulcrum. This has allowed us to unify the exercise into one document for both iOS and Android users.

Lab 2 shows you how to bring your field data into QGIS. This includes a tour of the QGIS interface, and how to map coordinate data stored in a spreadsheet.

Lab 3 is named Combining Field Data with other Organizational Data. It shows you how to work with coordinate systems in QGIS. It also covers how to join tabular data to the attribute table of a GIS layer. This is a step that often has to be done to merge socioeconomic data from the U.S. Census to census geography such as tracts or block groups. It concludes with a lesson on address geocoding. This is the process you use to produce points from addresses.

Lab 4 shows you how to do some basic spatial analysis. You learn how to clip data to your study area, measure proximity, query your data to select features and calculate areas/ density.

In Lab 5 you learn how to use some of the great data visualization techniques found in only in QGIS. The lab then walks you through how to compose a map. Along the way you learn some data styling tricks and how to use the Print Composer.

The series concludes with Lab 6 Data Visualization with Carto. Carto underwent a major update and rebranding since the first edition of these labs were created. You can use this exercise to see how to work with the new Carto Builder interface and tools to create an online map of your results. It covers uploading your data, styling and sharing your map with others.

The four labs that deal with QGIS have been updated to include some exciting new features that have been added to QGIS in the last year. Links to the lab data are included. So head to the Resources page and build your Community Health Mapping skills!

GIS as an Educational Tool at MUSC

Submitted by Jennifer Rewolinski

Dr. Deborah Williamson is an Associate Professor in the College of Nursing at the Medical University of South Carolina (MUSC), Charleston. Dr. Williamson, Community Health Maps (CHM) and MUSC have partnered in providing training that integrates GIS and CHM tools for a high school Teen Health Leadership Program. Dr. Williamson has worked with both community members and students.


Dr. Deborah Williamson (MUSC)

Dr. Williamson believes that, “GIS has the potential to substantially increase community engagement and is truly a concept of the neighborhood taking control of their data.” She notes that while researchers might study a community, that a community’s input is essential to understanding the cultural and environmental context surrounding health issues: “GIS mapping puts the community members on more of a level playing field with their research partners.” GIS can empower and educate community members to identify their key issues, to become a part of an analysis, and to provide solutions. When communities are given the opportunity to map their own health, discovery, and awareness, positive changes can result.  When a community feels it has more of a say through engagement with GIS, or communication with a map, intervention is more likely to be effective.

For the past three semesters, Dr. Williamson has used GIS in her own classroom as a capstone project for population health students.  They, “find it fun and can take it with them into other settings, it fits into the world of new technology, and it takes people to the next step of looking at health issues.” Mapping offers a different way to help students visualize Social Determinants of Health and to make the connection between what population health is, and the factors that promote or deter it.


MUSC students presenting their capstone work at the APTR Conference in Albuquerque (April 2016)

Finally, Dr. Williamson sees GIS as bi-directional: it supports visualizing gaps and assets while also providing the ability to disseminate and build on information via intervention programs to improve health outcomes and strengthen communities. GIS is also broadly applicable to almost any discipline and easily used by those with little expertise. “Presenting raw data to a community or students doesn’t mean a lot,” Dr. Williamson comments, “but when that same data is aggregated visually it instantly communicates a message to any audience.” GIS is clearly suitable as an effective educational tool in the classroom and in communities.

CHM thanks Dr. Williamson for her continued collaboration and time spent advancing the CHM program through use of the CHM tools at MUSC. CHM values our partnership with MUSC and hope that the future is as mutually beneficial as the past few years.

Field data collection for the CHM workflow bridges the divide between learning in a classroom and experiencing conditions in a community. For the capstone project, students use CHM labs and parts of the CHM workflow, including phone data collection with iForm or Fulcrum, integration of the data into QGIS, and presenting the data with Carto or Google Maps. Dr. Williamson’s students often upload their data from iForm to Google Maps because of its familiarity and easy access.

One student project involved identifying migrant camps as a community in need, and assessing the community through surveys and key informant interviews.  When the data showed that migrant workers often lack knowledge of health information and access to healthcare services, students mapped locations of migrant camps near Charleston, SC in relation to urgent care facilities and shared the data with the migrant outreach workers from a local community health center. Later, an intervention was developed to provide hands on CPR and first aid instruction to 60 workers. This project displays successful application of CHM tools in an educational and community context resulting in an intervention that may offer real change.


Map of MUSC Population Health student’s capstone project showing the locations of migrant camps and urgent care facilities in Charleston, SC.

CHM Workshop at the National Tribal Forum in Spokane, WA

This week the Community Health Maps team is heading to Spokane, Washington to teach a workshop at the National Tribal Forum for Excellence in Community Health Practice! We are honored to participate and engage a new community of mappers.2016-08-29_161231

It is a four hour workshop and by the end attendees will have:

  • Built their own data collection form in Fulcrum
  • Gone outside and collected some points
  • Made an online map of what they collected in Carto
  • Learned how to work with QGIS!

We’ll report back on how it goes when we return. Stay tuned!

So What is Open Source Exactly?

This term ‘Open Source’ pops up in discussions about Community Health Maps and the blog and I realize many may not really know what it means. That’s OK, I’m going to explain it here. From both licensing and software development perspectives, there are two broad categories of computer software: proprietary and open source. The figure below shows some examples of both types.


Examples of Open Source & Proprietary Software

Proprietary Software 

Proprietary software is created and sold by a corporation. They create software and sell it to make a profit. When purchasing it you may also be paying for the privilege to get help and support using the software. Or you may have to pay extra for that privilege. Two examples of proprietary software are Microsoft Office and Esri’s ArcGIS. There is also a license that accompanies a proprietary software package. When you purchase software, you are actually just buying a license that gives you the rights to operate the software. You never actually own the software itself. That software license will restrict use in some way:

  1. the number of computers you are allowed to install the software onto,
  2. the time period that the software will operate, and
  3. the number of features you are licensed to use.

Open Source Software

Open source software (OSS), on the other hand, is created by a community of software developers (programmers). It is created to solve a common problem and is made available freely for everyone’s use. Open Office, Android and QGIS are examples. Open source software also comes with a license. That license tends to grant rights to users. For example:

  1. The freedom to run the software for any purpose.
  2. The freedom to study how the software works.
  3. The freedom to redistribute copies so you can help your neighbor.
  4. The freedom to improve the program.

Access to the source code may not be important to most, but the freedom to use the software as you see fit very well may be.


Why Give it Away for Free?

To many it is counter-intuitive for something of value to be given away for free.  However, open source software development isn’t entirely altruistic. Most of these programmers work for companies providing services with the software. Those involved in an open source project simply feel that this is a better way to create software. There are several reasons for this:

  1. there are a lot of “eyes” on the code and bugs can be spotted and fixed quickly,
  2. having access to the source code let’s you understand how the software is working, it’s not a ‘black box,’
  3. you are not locked into a particular vendors system, licensing scheme or software release schedule,
  4. you have the freedom to create any missing functionality that you need
  5. you benefit from the contributions of others and vice versa.

Making Money with OSS

Obviously you can provide services using OSS. However, there are other ways to make money with open source. Companies like Facebook, IBM, Sun, and Google are all heavily involved in open source. Let’s take the example of Google. They may be the world’s largest open source company. One of the keys to their business are vast server farms, which include several million servers. Google never would have been able to get their company off the ground if it weren’t for the Linux operating system. The cost of putting a proprietary operating system like Windows on all those servers would have been prohibitive. Now their open source Android operating system is the most popular on the market with a 66.5% market share. In another example, even Esri’s ArcGIS includes some open source software components ‘under the hood.’ This is because some open source software licenses allow that software to be bundled with proprietary software and sold for profit.

Any given open source software is considered a ‘project’ and they aren’t all user friendly and useful. You still have to determine if the software will meet your needs. An important aspect is getting help and support. Things to look for include a good online manual, ‘how-to’ books, and an active listserv.


Let’s take QGIS as an example. It has fantastic support. It has a great online manual, training material, case studies, sample maps, commercial support, email listservs, plus a number of ‘how-to’ books written by people who use QGIS. The QGIS project does not have a corporation behind it. It has about 30 independent but dedicated core developers. They work in a democratic fashion, voting on new features to be implemented. As an end user you can provide input with feature requests! With QGIS, if there is a feature you need that doesn’t exist, you can hire (sponsor) a programmer to create it. It then may become part of the core program or it may be written as a standalone plugin. That feature then becomes part of the software and everyone benefits. As a user of the software, you can easily contact someone involved in developing the software and ask questions and request features. With proprietary software you never have such direct access to the development team. You can also donate to the QGIS project. Your donation will pay for developers to fix bugs and implement new features. Beyond programming there are many ways people can contribute to a project like QGIS. You can report bugs when you encounter them, write and translate documentation, contribute a case study, and write books.


Open source is both a development methodology and a software license. In the end it is really impossible to say that a proprietary software like ArcGIS is better than the open source equivalent like QGIS or vice versa. You must decide if either works for you, and freedom and monetary cost may be part of that decision.

End Note:

There are a lot of acronyms in GIS and specifically open source GIS. Here are some you may encounter:

FOSS = Free and Open Source. Historically there were two similar software movements, Free Software and Open Source software. They are so similar that they now are lumped together, and people simply use this acronym when talking about them.

FOSS4G – Free and Open Source for Geospatial. This is free and open source software specifically for mapping. OsGeo (below) holds annual open source GIS conferences called FOSS4G. The next is coming up later this month in Bonn, Germany.

OsGeoOpen Source Geospatial Foundation – this is a non-profit organization whose mission is to foster global adoption of open geospatial technology by being an inclusive software foundation devoted to an open philosophy and participatory community driven development. To be considered an OsGeo project a software must meet certain requirements. QGIS is a project under the OsGeo umbrella.

How Does Esri Software Fit into the CHM Workflow?

Community Health Maps (CHM) necessarily focuses on low cost and open source tools. This is because our goal is to find mapping tools that can be used by any community group, no matter the budget or resources. However, that doesn’t preclude people from using Esri software or other proprietary mapping tools too.


One benefit of using Fulcrum for data collection, and QGIS for analysis and cartography, is that they both support a wide range of common GIS formats. This means that the data you’ve created via these two platforms can be easily brought into Esri’s ArcGIS software. Similarly if you have data you have created with Esri tools they can be brought into QGIS or Carto. This feature is known as ‘interoperability’ and QGIS is highly interoperable. For example, QGIS can work with shapefiles, Esri personal and file geodatabases, KML and over 100 other formats!

From the outset we knew there were many scenarios for mapping software being used in public health and community organizations.  For instance, there are larger organizations who are already using tools such as Esri’s ArcMap, ArcGIS Pro or ArcGIS Online. With this scenario there are still several reasons the CHM mapping tools could be useful.

  • It might be that the organization doesn’t have enough Esri licenses for everyone in the office who’s interested in doing mapping work. In this case Fulcrum, QGIS or Carto could be used to fill the need.
  • An organization may find that their Esri license doesn’t give them access to certain tools they need. They could use comparable tools in QGIS to fill the need, without having to pay extra license fees just for one or two extra tools.
  • There may be smaller affiliated satellite groups that don’t share the same access to the software. In this case, these groups could use CHM suggested tools. Because of good interoperability they would then be able to provide data back to the central hub, where they could be incorporated seamlessly with the rest of the organizations data.
  • There may be certain tasks that are easier and faster to do in one piece of software and others that are easier in another. For example, I use both ArcGIS and QGIS daily to do different things. Many beginners also find QGIS to be more intuitive. GIS is simply a tool and by incorporating QGIS you are giving yourself a bigger toolbox.

If you are in an organization using another software package don’t worry. The tools we are promoting as part of this project can be integrated quite seamlessly with your current tools. It doesn’t have to be Coke or Pepsi, or Ford or Chevy. You can have both!

Mapping Curb Ramp Accessibility around a Silver Spring, MD Assisted Living Facility

Submitted by Jenny Rewolinski, University of Maryland, B.S. Community Health 2016

I just completed a spring internship with the National Library of Medicine (NLM). My goal was to demonstrate what a typical user of the Community Health Maps (CHM) blog might experience, while using the low cost resources it reviews to develop a mapping project with a public health focus. I read through the case studies on the CHM blog and used its labs to develop my project plan and to guide my related decisions.

Because of my experience with elderly relatives and my background in public health, I centered my project on how the senior population of a nearby Assisted Living Facility might safely navigate local sidewalks. According to the 2014 American Community Survey, 23% of people over 65 have some sort ambulatory disability. With this in mind, I decided to map local curb ramps –sloped transitions between sidewalks and streets which function as accessibility enhancements to help those with mobility issues to cross streets safely.


Figure 1. Curb Ramp Data Collection using the iForm app

I used CHM Lab 1: Field Data Collection to learn how to design my own data collection form using iForm. My Curb Ramp form captured curb ramp location, conditions, and other observations such as seniors using the curb ramps, steep or damaged curb ramps, and a lack of sidewalks in the area. As discussed in a prior blog post, How Accurate is the GPS on my Smart Phone?, phone geolocation is usually accurate up to 8 meters. This was not precise enough for my curb ramp data, so I corrected for this on my form.  Over the course of 8 hours spanning 2 days, and with 2 other interns I collected 103 existing curb ramps and locations where curb ramps might aid accessibility.


Figure 2. iForm Curb Ramp Data Collection Form

Next, I brought my iForm curb ramp data from my phone into the QGIS software by using instructions from CHM Lab 2: Bringing Field Data into QGIS.  I also used CHM Labs 3: Combining Field Data with Other Organizational Data and CHM Lab 4: Basic Spatial Analysis  to add data layers and to perform spatial analysis to finalize my map.


Figure 3. Curb Ramp Accessibility of Senior Population of Silver Spring Assisted Living Center Map

This is my project map! I completed construction of my map using CHM Lab 5: Cartography with QGIS. In addition to my curb ramp data points, I added data layers for sidewalks, roads, places of interest (such as grocery stores, restaurants, bus stops,  theaters), and my Assisted Living Facility. My goal was to raise awareness of how accessibility can impact seniors’ sense of autonomy and empowerment, and their ability to exercise and to lead a healthier lifestyle. This map also provides recommendations for where more curb ramps should be placed based on observations during data collection. I plan to discuss this map and curb ramp recommendations with the city of Silver Spring and to create “safest route” guides for popular local destinations.


Figure 4. A Safest Route Guide example showing safe and dangerous routes based on location of curb ramps and sidewalks

GIS has a huge potential to help us analyze health issues. When I began my project at NLM, I thought I would simply be mapping the location of curb ramps near a local Assisted Living Facility; however I discovered the significant need for more curb ramps as well as sidewalks around my project area.

I believe the conclusions I was able to reach by using the low cost CHM resources CHM are accurate and workable. I came to NLM with little to no GIS knowledge yet I learned from the CHM GIS labs, collected curb ramp data points and created a map that may bring awareness to a public health issue. In doing so I believe my experience is typical of many CHM users.

If I can do it, you can too!

Discover QGIS – A new QGIS workbook!

Two years ago, myself and several colleagues authored the GeoAcademy which is the first ever GIS curriculum based on a national standard – the U.S. Department of Labor’s Geospatial Competency Model (GTCM). The GTCM consists of the knowledge, skills and abilities needed to be a working GIS professional.  Our team was honored with the 2015 GeoForAll Educator of the Year award for this effort. The GeoAcademy consists of 5 complete college courses.

  • Introduction to Geospatial Technology Using QGIS
  • Spatial Analysis Using QGIS
  • Data Acquisition and Management Using QGIS
  • Cartography Using QGIS and InkScape
  • Remote Sensing Using QGIS and GRASS

This winter I converted the curriculum to fit into a convenient workbook format with Locate Press. The workbook is called Discover QGIS.

As you may be aware, QGIS is evolving rapidly. A new version is released every 4 months!  Due to this rapid development pace each spring a long-term release (LTR) is created. The LTR version is supported for a calendar year and is better for production environments. Originally written for QGIS 2.4, the GeoAcademy material in this workbook has been updated for use with QGIS 2.14 LTR. It therefore represents the most up-to-date version of the GeoAcademy curriculum. In addition to working with QGIS, it also includes exercises doing analysis tasks with the powerful GRASS GIS software, both alone and via the GRASS QGIS plugin. The cartography section includes exercises with InkScape. Here you’ll learn how to begin a map in QGIS and use InkScape to finish a publication quality map.

At the moment the digital version of the workbook is available as a Preview Edition for only $24.99. Purchasing this preview entitles you to the full version when it is released. There are just a few formatting issues to resolve.

This book will be a great resource for Community Health Mappers wanting to build their skills. The 470 page workbook comes with exercise data, challenge exercises and solution files!

Discover QGIS

Discover QGIS