Posts Tagged ‘web mapping’

Notes from the Open Geoportal National Summit

Wednesday, October 30th, 2013

This past weekend I had the privilege of attending the Open Geoportal (OGP) National Summit in Boston, hosted by Tufts University and funded by the Sloan Foundation. The Open Geoportal (OGP) is a map-based search engine that allows users to discover and retrieve geospatial data from many repositories. The OGP serves as the front-end of a three-tiered system that includes a spatial database (like PostGIS) at the back and some middleware (Like OpenLayers) to communicate between the two.

Users navigate via a web map (Google by default but you can choose other options), and as they change the extent by panning or zooming a list of available spatial layers appears in a table of contents beside the map. Hovering over a layer in the contents reveals a bounding box that indicates its spatial extent. Several algorithms determine the ranking order of the results based on the spatial intersection of bounding boxes with the current map view. For instance, layers that are completely contained in the map view have priority over those that aren’t, and layers that have their geographic center in the view are also pushed higher in the results. Non-spatial search filters for date, data type, institution, and keywords help narrow down a search. Of course, the quality of the results is completely dependent on the underlying metadata for the layers, which is stored in the various repositories.


The project was pioneered by Tufts, Harvard, and MIT , and now about a dozen other large research universities are actively working with it, and others are starting to experiment. The purpose of the summit was to begin creating a cohesive community to manage and govern the project, and to increase and outline the possibilities for collaborating across institutions. At the back end, librarians and metadata experts are loading layers and metadata into their repositories; metadata creation is an exacting and time-consuming process, but the OGP will allow institutions to share their metadata records in the hope of avoiding duplicated effort. The OGP also allows for the export of detailed spatial metadata from FGDC and ISO to MODS and MARC, so that records for the spatial layers can be exported to other content management systems and library catalogs.

The summit gave metadata experts the opportunity to discuss best practices for metadata creation and maintenance, in the hopes of providing a consistent pool of records that can be shared; it also gave software developers the chance to lay out their road map for how they’ll function as an open source project (the OGP community could look towards the GeoNetwork opensource project, a forerunner in spatial metadata and search that’s used in Europe and by many international organizations). Series of five-minute talks called Ignite sessions gave librarians and developers the ability to share the work they were doing at their institutions, either with OGP in particular or with metadata and spatial search in general, which sparked further discussion.

The outcome of all the governance, resource sharing, and best practices discussions are available on a series of pages dedicated to the summit, on the project website. You can also experiment with the OGP via, Tuft’s gateway to their repository. As you search for data you can identify which repository the data is coming from (Tufts, Harvard, or MIT) based on the little icon that appears beside each layer name. Public datasets (like US census layers) can be downloaded by anyone, while copyrighted sets that the schools’ purchased for their users require authentication.

OGP is a simple yet elegant open source project that operates under OGC standards and is awesome for spatial search, but the real gem here is the community of people that are forming around it. I was blown away by the level of expertise, dedication, and over all professionalism that each of the librarians, information specialists, and software developers exuded, via the discussions and particularly by the examples of the work they were doing at their institutions. Beyond just creating software, this project is poised to enhance the quality and compatibility of spatial metadata to keep our growing pile of geospatial stuff find-able.

Plan Your Trip through the Roman Empire with ORBIS

Wednesday, June 27th, 2012

If you wanted to know the fastest route from Roma to Londinium in June of 300 AD or how much it would cost to ride the shortest distance at ox cart speed to Constantinopolis, check out ORBIS. Researchers at Stanford have created a model of Ancient Roman transport networks over land and sea composed of 751 points (cities, landmarks, mountain passes) and thousands of linkages.

The model simulates the average distance of a large group of travelers taking a given route in a given month. The frictions of distance, terrain, climate, and monetary expense are all accounted for in the model and you have the ability to set many of the options. The technical aspects of the project as well as its historical bases are thoroughly documented. The output consists of route maps (which you can download as KML or as CSV) and interactive cartograms. The platform is an open source stack – PostgreSQL with PostGIS, Open Layers, Geoserver, and some JavaScript libraries.

Check it out at

The fastest route from Roma to Londinium in June? A boat ride across the Mediterranean to Narbo, foot/army/pack animal across southern Gaul, and a coast-hugging boat ride from Burdigala will get you there in 26.6 days and 2,974 kilometers. That carriage to Constantinopolis would cost you about 2,087 denarii and would take 128 days at ox cart speed – perhaps you should consider a fast military march instead?

Freely Available World Bank Country Data

Saturday, September 11th, 2010

This actually happend a little while ago, but for various reasons I haven’t been able to keep up with posting…

Our library had been subscribing to the WDI (World Development Indicators) database from the World Bank, but we were recently informed that the product was being discontinued and all of the data from the WDI and a number of other World Bank datasets would now be freely available from their data portal at

You can download an indicator for all countries by browsing through a list of all 300, or drill down by broad topics. Select an indicator and you can view a table with the most recent data, or a graduated circle map. If you download a table you can choose between an Excel or XML format. If you download the Excel format you get all years for all countries for that particular indicator from 1960 to present; but for many indicators you end up with a lot of null values up until this decade. If you go the XML route, the nulls are omitted and only years with data are provided. Unfortunately, in neither case do you get any unique identifiers like an ISO code.

Fortunately, power users can opt to download an entire data set, such as all of the WDI Indicators, in one file via their data catalog. In this case you have the option for Excel (xlsx only) or CSV, and the records I looked at DID contain ISO codes for each country (3 letter alpha). It looks like they’re also letting people tap into an API, so you can build web applications that harness the data directly from their repository.

In addition to browsing through indicators, you also have the ability to pull up a profile for a particular country to view several indicators for one particular place. They have a snazzy dashboard with stats, charts, and a reference map.

NY Times Interactive Maps

Sunday, March 29th, 2009

The New York Times has been putting together some great, web-based, thematic maps lately. I thought I’d provide a summary of some of the latest and greatest here.

US Maps

  • Immigration Explorer – Explore foreign born groups for the United States by county, based on the decennial census from 1880 to 2000. Choropleth maps of the largest immigrant group per county and graduated circle maps depicting the size of each group. 3/10/2009.
  • The Geography of a Recession – Choropleth map of the US that shows the annual change in unemployment by county. Lets you filter by county type (urban, rural, manufacturing areas, housing bubbles). 3/7/2009.
  • A Growing Detention Network – a graduated circle map of the US that shows detention centers where people are held on immigration violations, by number of detainees and type of facility. 12/26/2008.
  • Where Homes Are Worth Less Than the Mortgage – State-based US choropleth and graduated circle maps of the housing and debt crisis. 11/10/2008.

NYC Maps

  • New Yorkers Assess Their City – How New Yorkers rate their neighborhood based on quality of life, city services, education, transportation and crime. Based on a large survey of city residents. Choropleth maps of community districts. 3/7/2009.
  • Census Shows Growing Diversity in New York City – Choropleth maps show median rent and median income by PUMAs in 2000 and 2007. An example of mapping 3-year ACS data by PUMAs to show patterns below the county level. 12/9/2008.

World Maps

  • A Map of Olympic Medals – A cartogram of countries based on the number of olympic medals they’ve won for every olympics from 1896 to 2008. Mouse over to get medal counts. 8/4/2008.

Social Explorer and New ACS Census Data

Thursday, January 22nd, 2009

This is kind of a follow-up to my last post – the Social Explorer, a great interactive mapping site that allows you to map US Census data, has added the 2005-2007 American Community Survey data to their site at the PUMA level. This is the smallest geographic area that is available for recent data, until we get to the 2010 Census and 2010 ACS. At this point you can look at total population, race, and Hispanic ethnicity. It looks like you can make maps, but you can’t export the data unless you subscribe to the full version.

The Social Explorer allows you to map a wide selection of decennial census data all the way back to the 1790 census (they have a partnership with NHGIS, which provides historical data and boundary files for free download with registration). Tract-level data is available back to 1940. While you can map the data, and you can generate slideshows and download static maps as image files, you can only generate reports for the 2000 census. In order to get full access for report generation and other features, you’ll have to subscribe (or find access to a library that does).

Social Explorer also works with ARDA (Association of Religious Data Archives) to create maps of county-level religious affiliation (since the US Census does not collect this data by law). Of all the interactive mapping sites I’ve seen, the Social Explorer is one of the slickest and easiest to use.

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