GIS for All: The Fairfax County Story


Once upon a time, there was a young girl living in Fairfax County, yearning to go to school. She wanted nothing but to attend the best school in the safest neighborhood with a good police force. But the problem was that she had no way of figuring out which schools were in which areas. In the modernized version of this tale, she was visited by the MarkLogic fairy, and GIS data was at her fingertips. Together, MarkLogic and Fairfax County created a new platform that gives the citizens of the region access to important GIS data.

Fairfax County, Virginia wanted to upgrade their existing Police Events application. This application allowed the public to search, filter and map police service calls by type, location, and date as well as access preliminary police investigation data from Fairfax County’s 9-1-1 call center. The application resulted in multiple issues such as data currency, scalability, data consolidation, scalability, query time, and search performance. By working with MarkLogic Enterprise NoSQL database platform, Fairfax County’s Department of Information Technology currently has the capability to answer complex queries using its public-facing GIS data, ultimately making it easily accessible to both county employees and county residents.

During Wednesday’s Virtual Summit training “Simplifying Your Search: Open Up Your Data with GIS,” James Callahan, GIS Application Developer for Fairfax County, Virginia, and Mark Ferneau, Managing Principal Consultant at MarkLogic, discussed how Fairfax County created a new, easy-to-use GIS search engine.

Opening Up GIS Data for County Staff and Public Accessibility

MarkLogic is the new generation database, unlike the platform and system specific databases of the past that were less flexible. This model is supports all types of data, whether unstructured, semi-structured, or poly-structured. By using one database platform, you get faster time to results, you can do data analytics, you can do queries across a massive amount of data simultaneously,” said Ferneau.

Fairfax County is 400 square miles and is home to one million Virginians. It is also home to ten Fortune 500 agencies and various government agencies such as the CIA. Although Fairfax County is fairly sophisticated and powerful, one major thing this region was lacking was an effective way to share GIS information with the public and county officials. “What they needed was a platform that application developers could use to effectively search and use critical GIS data such as crime information, school locations, voting precincts, and more, and they needed to do it with a modest database,” said Ferneau. “MarkLogic is the database currently for a number of Fairfax County applications.”

Before MarkLogic, Fairfax County had multiple data sources, new data sets and formats, a limited query and filtering capability, and limited usage of the data due to the complexity of the information, causing it to be difficult to access. After MarkLogic was implemented, the county had a high-powered, uniformed data platform that reduced costs by improving access to government data. Application developers can create customized applications just by using this one platform.

Increasing Staff Productivity and Delivering Better Services to the Community

There are hundreds of datasets in the enterprise GIS database with multiple schemas. The basic search tools in GIS databases are not always easy to use nor meet our needs. Searches are incredibly specific and challenging for non-GIS professionals because you have to know which layers and columns to search, and they have to be searched one layer at a time. In order to search across a large portion of the GIS database in one operation, this would be extremely slow and costly.

Callahan asked an important question that Fairfax County was determined to answer: “In our public facing web applications, how do we make more information easily searchable to the general public?”

It is difficult to create a standardized output format that all layers with their unique data schemas can share. Callahan looked to design a GIS search engine with MarkLogic that could make information more readily available. It had fulfill multiple requirements, including being accessible over the Internet, having the ability to return information in multiple data forms, having the ability to add new datatsets as they are discovered, and excludability of certain GIS datasets from unconstrained searches.

Callahan discussed the Police Event Viewer as an example of a successful application for unconstrained GIS searches. For the Police Event Viewer, citizens can search through the 400,000 criminal events spanning over the last decades. The search can be constrained by date range, type of event, and several different geographic boundaries (i.e. type of location and location, distance, etcetera). This is one of the many ways GIS is utilized in Fairfax County. He also highlighted the bright future for the GIS database for Fairfax County, such as making county developers aware of the GIS database and encouraging them to include it in their applications where GIS searches are desired.

To listen to the complete archive, click here.

GovLoop recently hosted its State and Local Innovators Virtual Summit, an all-day, virtual event with six different online trainings, networking opportunities and resources to help you do your job better. Be sure to read the other recaps here.


Featured Image Attribution: [puamelia]

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Catherine Ann Taylor

Having trouble completing the evaluation on this presentation. Can’t seem to find it….
The possibilities of GIS as a tool and Fairfax county’s leveraging that use were very intriguing though. Good papers for further exploration.

Catherine Andrews

Hi Catherine, if you log into the resource center back in the virtual environment and search for “CPE” you should be able to find it. Email me at [email protected] if you are unable and I will help you out!