Why is geospatial metadata so important?

June 18, 2015

Gordon Plunkett

Governments around the world have been collecting geospatial data for some time and are now making archived and recently collected copies of this data available to the open data community and the public. However, developers and users can’t discover and consume this data without being able to find it and determine if it is fit for their purposes. That’s where metadata comes in. Find out why it’s such an essential component of any GIS.

Recently, I attended both the Canadian Open Data Summit and the International Open Data Conference in Ottawa where I was surprised about two things.

First was the large number of attendees at both conferences who were either providing or using open data. Of all this available open data, it was remarkable how much of it was geospatial data. This was a pleasant surprise that shows the availability of open geospatial data and its use is important and growing.

The second surprise was the usefulness and importance of metadata. For those who don’t know what metadata is, metadata is created to describe datasets so people can find specific data, know what the dataset contains, determine its quality and content, ascertain how this dataset differs from similar datasets and uncover other pertinent descriptive information about the individual instances of the open data.

Geospatial data is often more complex than other types of open data because of the geographic, temporal and type aspects of the data – which are important considerations when selecting or using the data. So, how does one determine these characteristics of the dataset?

These data characteristics are documented in the metadata record. Most data management systems allow users to search the metadata for particular data characteristics that are important to the user.

For many decades, the library community has been developing and using metadata standards for locating books and other material. When there was a proliferation of geospatial data, the geospatial community got together and developed metadata standards for locating and selecting geographic data.

With the prevalence of geographic data these days, metadata is an essential element for documenting and managing all of this geospatial data. Metadata is now considered an essential component of any geospatial system and metadata processing must be taken into account in any organization’s operational workflow.

Are things all rosy in the world of geospatial metadata?

Well, not quite. At one of the open data workshops I attended, one of the participants who worked at a Canadian University Library spoke about the proliferation of metadata standards for open data and the issues that this creates. This participant said that for their library, they need to support the following metadata standards: FGDC CSDGM, ISO 19115, North American Profile, CKAN, Dublin Core and MARC. There are, of course, crosswalks (a field ‘mapping’ table) from standard to standard, but these are generally not perfect conversions and often involve losses of metadata information.

For geospatial metadata, the landscape is not much better. In fact, there are a plethora of standards currently in use that touch on geospatial metadata. Most of the world has converted to the ISO 19115 family of standards, except the US, which is slowly inching their way to ISO implementation. This will eventually deprecate the FGDC CSDGM metadata standard, but there will still be lots of other standards to support and use.

Geospatial metadata is such an essential component of any GIS or other geospatial system. In fact, the metadata motto should be: “geospatial data without its metadata does not exist.” Easy-to-use tools would go a long way in making metadata creation and management much easier. But for now, let’s carry on creating metadata using the tools we have so that users can continue to discover and harness open geospatial data for the betterment of us all.