Long Island Index Expands and Improves Interactive Community Map

By Directions Staff

Last month, the City University of New York's (CUNY) Mapping Service at the Center for Urban Research developed a new application, the "Long Island Index," that makes data about Long Island available to citizens, local developers and politicians to help them discern local and regional trends using a variety of geospatial technologies. Directions Magazine interviewed Steve Romalewski, director of CUNY Mapping Service at the Center for Urban Research, CUNY Graduate Center, and by Ann Golob, Ph.D., director of the Long Island Index about the project, the technology and what's ahead.

Directions Magazine (DM): Can you provide details on the technology platforms used to create the online mapping system and the reasons you chose those solutions? Microsoft Virtual Earth seems to be the base visualization platform, but please provide other information?

Steve Romalewski/ Ann Golob (SR/AG):
Microsoft Virtual Earth is just one part of the application (though an important part - it provides the "bird's eye photos" accessible when you click on the map). The technology platforms include:
  • ESRI ArcGIS Desktop (to create MXD files for the transportation and reference layers, land use maps, demographics and regional views) and ArcSDE/SQL Server to manage the data sources
  • ESRI ArcGIS Server to generate Web map services from the MXD files. We also use ArcGIS Server to generate cached tiles for the land use map layer.
  • OpenLayers consumes the WMS resources, manages and displays the map layers, and provides map navigation tools.
  • Dynamic data feeds are also provided via REST web services (such as village-specific statistics and comparison statistics).
  • Ext.js provides the overall framework for the website itself and enables us to relatively easily integrate AJAX-style tools such as dynamic transparencies, collapsible panels, floating windows populated with dynamic data and charts, etc.
The Center for Urban Research (CUR) at the CUNY Graduate Center created the MXD files, customized OpenLayers and ext.js, and developed the overall application. Note that with the exception of the satellite/aerial photos, the map layers for this project are all hosted by CUR. There was too much data to simply mash it up with a basemap from Google Maps or Microsoft, for example, and we wanted control over the cartography.

The maps use ESRI's platform on the back end because CUR has extensive experience using ESRI products to generate maps (online and offline). Though CUR has historically used ArcIMS to manage and serve online applications, the learning curve was minimal to install and use ArcGIS Server's tools.

The Center did explore open source map server options such as MapServer and GeoServer. But using those tools would have required learning a new "language" in terms of map styling and online cartography (such as GeoServer's SLD files).

That said, CUR wanted to develop the front end of the application using tools that would provide the kind of user experience that is now generally expected of online maps intended for a wide audience. For example, we felt it would have been too onerous to require our users to first click a "hand" tool in order to pan around the map, or to click an "information" tool in order to access information from the map. The Center therefore evaluated several open source alternatives to ESRI's Web ADF and concluded that OpenLayers was best suited to our needs. (Going forward, ESRI's new JavaScript and/or Flex APIs may be worth considering for new applications.)

The hardware architecture is a three-tier configuration: 1) a Web server that manages Web traffic and the application itself; 2) a map server for ArcGIS Server; and 3) a data server that manages ArcSDE and SQL Server. The machines are Dell PowerEdge servers. The hardware is housed at the CUNY Graduate Center, whose Research Computing and Information Technology staff provide invaluable support to keep it all running.

DM: What was the impetus for putting this information online and sharing it with the public? Was there citizen demand for this application or was it the vision of a political leader?

A central goal of the Long Island Index is to make information about regional indicators easily and broadly accessible. We also try to localize the information as much as possible to make it especially relevant to people interested in their communities, as well as the island as a whole. Several years ago the Index website had provided "Community Profiles" consisting of static maps and tables highlighting Census data for each village, town and city on Long Island. The Index had removed those profiles when our website was redesigned two years ago, but we knew that we needed to provide better access to data like this - the Index regularly receives requests from public officials, the media and community groups for information about what the Index's indicators mean for their local areas. We also knew that we needed an easier way of helping people make connections among multiple issues - such as housing, transportation and jobs. An interactive map seemed like the logical approach.

Several open source tools made it possible for CUR to relatively easily meet these goals. In particular, components such as the dynamic transparency tool within the ext.js framework enabled CUR to transcend the traditional GIS approach of viewing one or perhaps two map layers at a time. The transparency tool coupled with OpenLayers' ability to quickly swap in and out different map layers - such as thematic Census layers and satellite imagery - facilitated the effect of viewing multiple map layers at once.

DM: You indicate that the website is in beta. What was the reason for calling this a "beta" launch, as the maps look fairly complete?

The "beta" version of the map was launched in October 2008. We conducted a webinar with a small group (three dozen people) of community leaders, GIS experts and local planning agencies to walk people through the site and seek their feedback. Since some of the mapping tools were relatively new (such as the transparencies), we wanted to "kick the tires" before doing a more public launch. The beta site was accessed by more than 300 people worldwide, including high school students, local public officials and agency staff, community leaders and industry representatives. We were able to incorporate their feedback before the site was officially announced in December 2008.

The map at www.longislandindexmaps.org is a public version, no longer in beta.

DM: Does the funding organization, the Rauch Foundation, have a public/non-profit relationship with Nassau County to support this activity? Please explain more about the relationship.

The Rauch Foundation does not have an official relationship with either Nassau County or Suffolk County. For the mapping project, both counties provided access to parcel-level land use data - GIS boundary files and parcel attributes - on a licensed basis. It is the first time that real property data from both counties have been combined and presented online in an interactive, thematic map format. We plan to continue working closely with county officials to access other data, as well as ongoing parcel updates.

DM: What is the three- or five-year vision for the Long Island Index? How will it develop further and what geographic data are you seeking next to incorporate online?

The Long Island Index publishes an annual report of indicators impacting the region. In January 2009 we will release our latest report and public opinion survey, with a focus on education. The interactive map will be updated with data related to education such as district-by-district analysis and individual school locations with links to detailed school "report cards" provided online by New York State. The goal is to use the interactive map to help reveal patterns of education funding and enrollment and how they might relate to housing characteristics, residential development, racial and ethnic diversity, and even public transportation options. We also expect to add information related to health, open spaces and brownfields.

In addition to new data, the Index map will incorporate updates to data we've already included in the maps as public agencies and others make this information available. Recent updates from the Census Bureau will be incorporated, as well as annual land use updates from Nassau and Suffolk counties.

Above all, we want to avoid adding data to the maps just for the sake of adding data. It is important that the maps continue to help reveal relationships of interest to the Index. For example, the wealth of education statistics compiled by local districts as mandated by state and federal agencies can be overwhelming. Simply tossing all those data into the mix would be counter-productive, helping to obscure rather than enlighten the public's understanding of what lies at the heart of educational challenges and how to overcome them. We will strive to be strategic in how we further develop the maps, while also responding to feedback and requests from the public.

Editor's Note Steve Romalewski added the following clarification: "Technically, the CUNY Mapping Service didn't create the Index itself, only the interactive mapping feature for the Index. The Index project itself is a multi-year effort by the Rauch Foundation and others, of which we're only a part."

Published Thursday, January 8th, 2009

Written by Directions Staff

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