Tag Archives: Analysis

Vector Borne Disease Surveillance with QGIS – A Series of Two Day Workshops

This spring, with funding provided by the Association of State and Territorial Health Officials (ASTHO), Kurt Menke developed a two day workshop that combines elements of the standard Community Health Maps workflow with vector borne disease surveillance analyses.

The workshop begins with an introduction to Community Health Maps, and learning how to use Fulcrum to develop a data collection form and collect community GIS data with a smartphone. Participants will then be introduced to QGIS. They will learn how to add the field data just collected, and symbolize it. They will then download some open data and create a map.

The second day focuses on a suite of mosquito trap data acquired from Madera County, CA, by Dr. Chris Barker at UC Davis. There are 5 years of mosquito trap data and mosquito virus testing data. There are also anonymized data for mosquito biting complaints, mosquito management zones, storm drain locations, parcels and roads.

Collectively this provides a rich yet manageable dataset. With it participants will learn to use to create information such as:

mosquitosPerYearChart.png

Trend graphs of mosquito populations through time via the QGIS Data Plotly plugin.

culexquinqheatmap

Heatmaps of mosquito populations per species

2019-05-23_173132

Calculations of the Minimum Infection Rate per year for West Nile virus (WNV) and St. Louis Encephalitis (SLEV) virus

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Identify parcels at risk due to their proximity to a fictional outbreak of Dengue Fever. This is done by buffering the outbreak location by the potential flight range of the mosquito species

This workshop represents applied real-world workflows. These are many of the standard products needed by public health officials and typically produced by researchers. Having this sort of analysis and data visualization available via an open source package means anyone willing to take a few days to learn can produce them! This is especially true as the needed input data can be collected via Fulcrum if they don’t already exist.

This workshop will be taught twice in June. Both workshops will be part of the Community Health Maps project and are partly funded by the National Library of Medicine (funding for the workshop is provided under a sub-award from the National Library of Medicine to ICF International). The first iteration will be taught in conjunction with the Insular Area Climate and Health Summit in Honolulu, HI. This will be attended by public health officials from many of the Pacific Territories.

The second workshop will be taught in Providence, RI at the GIS Surveillance Workshop. This will be attended by State based health officials.

This material really showcases the analysis and data visualization capabilities of QGIS.  It represents perhaps the greatest potential for applied use of Community Health Maps to date. This workshop will part of the suite of Resources available through the Community Health Maps program in the near future.

If you are interested in having this taught for you or your colleagues contact Kurt Menke (kurt@birdseyeviewgis.com).

 

Community Health Mapping: A New Year Review

To start the New Year I thought I’d begin with a review of Community Health Mapping (CHM). There are a lot of new project partners, and I thought it would be a good time to give a project overview. CHM is a collaborative effort between the National Library of MedicineCenter for Public Service Communications and Bird’s Eye View. The National Library of Medicine is funding the initiative.

The overall goal is to empower community organizations serving vulnerable or underserved populations with low cost, intuitive mapping technology. Therefore we’ve been working with programs organizations who:

  • Focus on vulnerable populations
  • Frequently use and collect data
  • Need effective, scalable & easy to use mapping tools
  • Lack resources (i.e., for proprietary GIS training & software)

We have identified a suite of tools that allow you to collect custom field data, analyze that data, combine it with other spatial datasets, and generate both static maps and/or dynamic maps on the internet. This allows organizations to collect and work with their own data, and if appropriate, share it with others. CHM involves three components that meet all basic mapping needs:

  • Field Data Collection
  • Desktop Analysis and Cartography
  • Internet Mapping
Community Health Mapping Workflow

Community Health Mapping Workflow

A given project may not require all three, however, collectively these components address the basic needs of all mapping projects.

Field Data Collection:

Rather than focusing on the use of expensive GPS receivers, we recommend the use of smart phones and tablets for these reasons:

  • Most community-based organizations already have them!
  • Many know how to use them
  • They’re intuitive
  • They’re portable
  • They come with an on board GPS receiver (iPhone 5 uses GPS + GLONASS)
  • Have on board cameras
  • Can connect to wireless networks
  • Access to the internet
  • Email is available
  • “There’s an app for that!”
SmartPhones and Tablets vs. Traditional GPS Receivers

SmartPhones and Tablets vs. Traditional GPS Receivers

Of course an important consideration is horizontal accuracy. You can read our blog post on that topic to see if mobile smart devices meet your project needs.

When collecting data you need to be able to develop your own custom data collection form. The top three mobile apps we have found are:

Desktop Analysis and Cartography:

After community field data collection, the next step typically involves bringing the data into a desktop GIS. This is the middle step in the workflow. Here the data can be viewed against basemaps such as Google or OpenStreetMap, and combined with other organizational data. This is also where analyses (proximity, density etc.) can be conducted. Presentation quality maps can also be generated in this step.

The software we found to be the best fit is QGIS. This is an open source desktop GIS software. It has many strengths:

  • It can consume many kinds of data, including all the data that would come out of the field data collection apps.
  • It is both intuitive and robust.
  • It has a large suite of geoprocessing tools for analyzing data.
  • It will run on Windows, Mac, or Linux.
  • It is free to download and install.
  • It is well documented.
  • There is a large user community.
  • New functionality is being continuously added. New stable versions are being released every 4 months!
Baltimore Diabetes Data in QGIS Desktop

Baltimore Diabetes Data in QGIS Desktop

Web Presentation

Often you may want to present an interactive map of your results. Interactive means the map reader can zoom in/out, pan the map and turn layers off and on. For this we recommend CartoDB.

You can sign up for a free account, which gives you 50Mb of storage space. Data can be collected with a smart phone or tablet and brought directly into CartoDB.  It is a very intuitive platform. You can literally drag and drop a spreadsheet onto the CartoDB page and have the data upload to your account.  It will accept the most common geospatial file formats including: spreadsheets and comma delimited text files with addresses or coordinates, KML/KMZ, GPX, and shapefiles.

CartoDB also has great documentation including:

Baltimore Diabetes Data in CartoDB

Baltimore Diabetes Data in CartoDB

In Conclusion

This blog has a lot of resources including reviews of mapping technology and case studies. You might begin by clicking on some of the links in this entry. We are also working on a 6 lab CHM curriculum that interested parties will be able to use to hone their skills. Stay tuned for that!

We are always looking for new partners and continuously work to support current project partners. If you are interested, or have questions please don’t hesitate to contact John Scott (jscott at cpsc.com) or Kurt Menke (kurt at birdseyeviewgis.com). Most importantly get out and do some mapping in 2016!

 

 

 

Map and Analyze Field Data with QGIS

After community field data collection, the next step typically involves bringing the data into a desktop GIS. This is the middle step in the workflow outlined in the Introduction. Here the data can be viewed against basemaps such as Google or OpenStreetMap, and combined with other organizational data. This is where analyses can be conducted. Presentation quality maps can also be generated in this step.

The software we found to be the best fit is QGIS. This is an open source desktop GIS software. It has many strengths:

  • It can consume many kinds of data, including all the data that would come out of the field data collection apps.
  • It is both intuitive and robust.
  • It has a large suite of geoprocessing tools for analyzing data.
  • It will run on Windows, Mac, or Linux.
  • It is free to download and install.
  • It is well documented.
  • There is a large user community.
  • New functionality is being continuously added. New stable versions are being released every 4 months!

 QGIS Browser:

QGIS has two main applications: QGIS Browser and QGIS Desktop. Browser allows you to preview your GIS data. It is similar to Windows Explorer, or Mac Finder, but is designed to work with GIS data. It has a File Tree, a main Display Window, Database Connections and Display Tabs (See figure below). It allows you to view basic information about a GIS layer and preview both the spatial features and the attributes. Data can be dragged and dropped from QGIS Browser to QGIS Desktop.

QGIS Browser

QGIS Browser

QGIS Desktop:

Desktop is the program for conducting analyses and making maps. It comes with tools for editing and manipulating GIS data. The main interface is similar to well known proprietary GIS packages with a Table of Contents along the left side. This shows your data layers and the symbol applied to them. The majority of the space is taken up with the Map Window (See figure below). Buttons along the left side allow you to add data to a map. Buttons along the top allow you to pan and zoom into the map. There are additional editing and data analysis tools available from menus.

QGIS Desktop

QGIS Desktop

With QGIS Desktop you can perform analyses such as calculating distances to resources, characterizing communities with socioeconomic data from the U.S. Census (NOTE: you will need to obtain data from the U.S. Census to do this), or generate new data like density surfaces.  The sky is the limit.

QGIS Desktop also comes with a Print Composer (See figure below). This opens in a separate window and allows you to craft a publication quality map. Common map elements such as a title, legend, scale bar, north arrow, logos, and text can be added. The final map can be exported in a variety of common image formats such as: jpg, png or tif. Maps can also be exported as pdf’s. If you want to do additional design work in a program like InkScape or Adobe Illustrator the maps can also be exported as svg files.

QGIS Print Composer

QGIS Print Composer

Resources:

While fairly intuitive, GIS work can still be rather complicated and full of jargon. There is a learning curve involved. To help with this we have resources that explain how to install QGIS and bring in data from the three recommended field data collection apps.

For more complete GIS training with QGIS there is the newly created FOSS4G Academy. This is a five course curriculum teaching GIS principles via QGIS. The material is available for free here: http://foss4geo.org/. The courses include:

  • GST 101 – Introduction to Geospatial Technology
  • GST 102 – Spatial Analysis
  • GST 103 – Data Acquisition and Management
  • GST 104 – Cartography
  • GST 105 – Remote Sensing

QGIS also comes with thorough documentation.

Download it today and try it out!