The Los Angeles Infill Scenario Mapping System allows planners to test out infill scenarios themselves, which takes some of the workload off the GIS Department.

People are moving back into urban centers, and the demand for infill housing in U.S. cities is on the rise. Infill is defined as the use of vacant land and property within a built-up area for further construction or development, especially as part of a neighborhood. According to the Urban Land Institute, the factors influencing this trend are varied but include disillusionment about life in the suburbs, where traffic, crime, and pollution are increasing, and the appeal of an urban lifestyle, where residents have easy access to restaurants, cultural attractions, and work. Dramatic increases in population also have city planners thinking more about infill development projects. According to the U.S. Census Bureau, Los Angeles, California, gained more than 209,000 people between the years 1990 and 2000. According to the Southern California Association of Governments (SCAG), the Los Angeles city share of the regional housing need for 2014 will be 112,876 new units.

City planners at the Los Angeles Department of City Planning (DCP) needed an agile, easy-to-use solution to help them identify potential infill development opportunities. Specifically, planners required the ability to assess underutilized land for infill development potential by screening larger areas, like census tracts, community planning areas, and city council districts.

The Challenge: Leveraging an Existing Database

During the last eight years, DCP has used the Zone Information and Map Access System (ZIMAS), an Internet-based GIS that utilizes ArcIMS, to access a parcel database consisting of nearly a million records. Originally developed in 1998 using MapObjects, ZIMAS was rewritten using ArcIMS in 2003 by the current principals of Esri Business Partner Altruvista of San Diego, California.

"ZIMAS is a comprehensive inventory tool of zoning and parcel information," explains Clint Daniels of Altruvista. "ZIMAS helps the user analyze that inventory for patterns to help policy makers make better use of a limited resource—land."

However, instead of researching one parcel at a time, DCP needed the ability to find all the parcels that met explicit criteria, taking advantage of the ZIMAS database but basing the analysis on existing geographic and political boundaries, linear features like roads, or exact locations like commuter rail station stops.

Planners Can Now Perform Simple Queries Themselves

In 2006, Solimar Research Group (SRG) of Ventura, California, was contracted by the City of Los Angeles to develop the Infill Scenario Mapping System (ISMS) based on a prototype application that SRG had developed earlier. SRG, in turn, subcontracted with IGIS Technologies, Inc., of San Diego, California, an Esri Business Partner, to develop the product.

The development team found that ArcGIS Server could easily handle the potentially large query results, and because DCP had specified that the application be built on .NET, the team also realized that, with ArcGIS Server, Microsoft ASP.NET AJAX (formerly Microsoft Atlas) and Yahoo! User Interface (UI) Library utilities and controls could be incorporated to help improve the Web application interactivity, speed, and overall user experience.

ISMS makes it possible for planners to formulate parametric queries against the ZIMAS inventory to find parcels that meet a particular range of requirements for infill development potential. Users interact with an easy-to-use Web application to create a scenario, either by filling in a form and submitting it or by responding to a wizard that helps them understand how the different input parameters affect the resulting scenarios. They can also load a saved scenario. Saved scenarios are XML files created from previous queries and can be easily shared among city planners.

ISMS includes administrative tools for connecting to different servers and datasets, which makes the system flexible and reliable. For example, DCP currently uses two servers on a rotating basis to support the constant updating of ZIMAS data; ISMS can be reconfigured to point at whichever server has the most current ZIMAS data.

Additional Possibilities for Using the Web Application

Even as planners tested the beta versions of ISMS, they saw its potential for helping them with issues other than infill development. For example, the same parameters could be used to identify possible sites for parks, community facilities, or cultural amenities. Reverse scenarios, such as identifying housing-rich areas, could be used to help attract jobs and businesses.

As ISMS matures, Jane Blumenfeld, principal city planner, DCP, envisions additional opportunities to communicate with Los Angeles citizens. "We are always updating community plans, and we can use this system as a community outreach tool and to help us quickly create what-if scenarios within the context of a public meeting. For example, we can model scenarios for potential pilot projects that may not work for the entire city but might work very well in certain portions of the city, like increasing population density near transit or adding a story to a building where there is a height limit. We're able to test it out and calculate how much more housing we could generate with these types of strategies before making policy changes."

City Planners Don't Need to Be GIS Experts

ISMS leverages the massive parcel inventory of ZIMAS and extends GIS capabilities to more than 150 planners at DCP in an easy-to-use Web format. They don't need GIS software on their desktop computers, and they don't have to be GIS experts. They just need a network connection. ISMS provides them with new ways to look at existing data—quickly and precisely—so they can evaluate current conditions in areas of concern or interest and tease out additional information.

"The Infill Scenario Mapping System boils down a complex problem into a simple map product," says Andres Abeyta, president of IGIS Technologies. "It uses GIS to take advantage of the city's significant and long-term investment in GIS data (namely ZIMAS), placing Web- browser-based analysis tools directly in the hands of the city and community planners.

More Information

For more information, contact Jane Blumenfeld, principal city planner, Los Angeles Department of City Planning (e-mail: Jane.Blumenfeld@lacity.org), or Dave Van Mouwerik, IGIS Technologies, Inc. (e-mail: vanmouwerik@igist.com).