How To Use It

Community mapping involves five broad steps.  As illustrated in the graphic below, the process begins and ends with local communities, and each step builds upon the information obtained in a previous step.  Although we have defined this approach in a linear fashion, some of the steps can be implemented simultaneously.

The process begins with community groups and residents identifying an issue or problem that can be resolved with the assistance of maps and data.  The community must take leadership in framing the mapping effort.  This initial step also involves forming a community mapping team. The second step is determining the most appropriate levels of geography (or simply, geographies) for the mapping project.  The third step is collecting data.  The fourth step is producing maps using the data collected in step three.  Finally, the maps are used by community groups and residents to resolve issues and problems identified in step one.

Each of the five steps is described in greater detail below.

Step 1: Identify Community Issues/Problems & Build Community Mapping Collaborative.     back to top
All community mapping efforts start with community based organizations and residents and their in-depth understanding of community conditions, assets, and problems.  Community knowledge is used to identify issues and problems, set benchmarks, goals and outcomes, locate opportunities for revitalization, frame data-gathering efforts, determine the appropriate types of geography and maps, and use maps for community building purposes.  By designing and leading the mapping process, community residents and organizations are better positioned to insure that the maps provide community benefit and accurately reflect community needs.  Community leadership also promotes community values in the mapping process and better equips community groups to use the resulting maps for advocacy and organizing purposes.

For example, in Providence , Rhode Island , community groups suspected that the sale of tax titles was a major contributor to instability in Olneyville-one of the city's most distressed neighborhoods. The project team used Geographic Information Systems (GIS) to map properties-on a parcel level-that were sold through tax sales and to identify properties that had had multiple owners and frequent turnovers.  The maps helped community members identify a specific root cause of instability: speculators were buying tax delinquent properties through auctions and allowing them to remain vacant.  The maps turned the problem of instability into an issue that could be acted on-land speculation. New legislation was passed to combat that speculation.

In addition to leading the design process, community groups should establish a community mapping collaborative with three types of expertise: 1) community knowledge, 2) data collection capacity, and 3) mapping capacity.  Community knowledge shapes the mapping process from the outset, and community groups are the primary end users of the maps.  Working with data from multiple sources requires the ability to make sure those data are accurate and in compatible formats. Finally, organizations with the technological capacity to map data are required to display and analyze the information gathered.  Without the participation of each of these key stakeholders, developing community mapping applications is challenging, if not impossible. Should an organization want to develop GIS capacity in-house, all three of these areas of expertise are still vital.

Step 2: Determine Appropriate Geography.   back to top
Selecting the appropriate geographies is one of the first decisions to be made in the mapping process.  As shown below in the graphic from Providence , Rhode Island , community mapping projects can use a range of geographic units for mapping, ranging from individual parcels to census tracts to entire neighborhoods.  Most initiatives will include several different geographies, from parcel to census tract.

The smaller the geography, the more detailed the data, but the more difficult it will be to acquire. Most equitable development mapping initiatives make use of parcel-level maps in addition to other geographies.  Parcel-based maps allow community practitioners to identify and track properties that are available for local development. These maps are unique for all municipalities, and base maps must be acquired from local sources.

For example, in Los Angeles , the Neighborhood Knowledge Los Angeles (NKLA) project uses parcel and census maps to illustrate the distribution of vacant properties compared to the race and ethnicity of the surrounding residents.  NKLA obtained vacancy information for individual parcels and race/ethnicity data for census tracts.

Examples of Geographic Units for Community Mapping
Providence , Rhode Island

Step 3: Collect Data.  back to top
Community mapping initiatives are only as strong as the data upon which the maps are built.  Maps that are most useful in a community context will likely consist of information from many sources.  There are four major data types used in community mapping projects: public statistics, administrative data, survey data, and private data.

• Public Statistics.  There are many public data sources important for community revitalization, including federal and state information like Census data, data from the Home Mortgage Disclosure Act (HMDA), and statistics from federal agencies such as the Department of Labor and the Department of Commerce. This information is usually available to the public at no cost.  Census data is the primary source of public data for neighborhood revitalization efforts and almost every community mapping effort highlighted in this tool uses Census data.  It can be categorized in five major groups: demographics, socio-economic characteristics, housing, business/economy, and transportation.

• Administrative data. Administrative data collected by state and local government agencies (e.g., tax assessors, police departments, city agencies, zoning offices, and school districts) are key inputs for community mapping projects.  These data are usually available for small levels of geography (smaller than census tracts) and are often available for parcel-level mapping.

• Original data: Surveys.   Many GIS projects augment public and administrative data with information collected first-hand by community organizations. This type of original data collection is the basis of many asset mapping programs, where community groups and residents map local assets and resources.  Data may be collected about assets including social networks, recreation facilities, volunteer opportunities, trees and green space, murals, and community gathering sites.  Data can be gathered by volunteers, including youth, students, and residents.  For original data collection to be most useful, it is important that the data collectors know why they are collecting this information and how it will be used.

• Commercial data.  Data is available for sale from companies like DataQuick and Dun and Bradstreet, which is often used by real estate brokers and others seeking current data on available properties.  This information is expensive, and only a few community mapping efforts make use of this resource.

Step 4: Create Maps.   back to top
Most mapping projects require a significant technology investment.  All but one of the community mapping projects reviewed in the Why Use It section were GIS-generated projects and many were Internet based, such as Neighborhood Knowledge Los Angeles and Philadelphia's Neighborhood Information System.  Here are five components necessary to use GIS:

• Hardware. Hardware is the physical computer on which GIS operates.  GIS software runs on a wide range of hardware types, from centralized computer servers to desktop computers. You do not have to buy a special kind of computer to run GIS. However, because GIS requires a very large amount of memory, it is often a good idea to dedicate a computer to the project.

• Software. GIS software provides the functions and tools needed to store, analyze, and display geographic information.  Most mapping projects reviewed in this tool used ArcGIS ( www.esri.com ) or MapInfo ( www.mapinfo.com ) software packages.  See www.geoplan.ufl.edu/software.html   for a comprehensive review of GIS software packages.

• Data. Data is the most important ingredient of GIS projects. GIS transforms tabular databases into layered geographic information or maps.  (See the above review of various data types.)

• People. GIS technology is of limited value without people who have the capacity to manage it and develop plans for applying it to real world problems.

• Methods. A successful GIS project operates according to a well-designed working collaborative and implementation plan.

As noted above, mapping community data requires not only investments in hardware and software, but also staff support.  For most community groups, developing the technological capacity in-house is too expensive.  Parcel-based mapping systems, powered by massive databases, require significant investments and on-going maintenance.  Therefore, many community organizations partner with technology or mapping intermediaries, such as universities, to maintain the GIS technology.

Tools and Costs for Developing a Web-Based GIS Application: Neighborhood Knowledge Los Angeles

The following example from the NKLA Web site highlights the cost of developing and maintaining a parcel-based GIS application. See NKLA's Web site for more documentation of the NKLA mapping application.

The figure below provides a general overview of the tools used to develop NKLA, as well as their associated costs. Overall, the estimated cost for hardware and software needed to develop and maintain the site is $26,400. The estimated cost for Web development (i.e. staff time in building the database and developing the Web site) is $76,600, based on three persons working full-time on the project for four months. It should be kept in mind that the budget for similar projects will vary greatly according to existing infrastructure, geographical scope, and quality of existing data.

Hardware and software tools

As community mapping projects increasingly make use of computers and the Internet, we are also seeing a need to strengthen technology infrastructure in low-income/low-wealth communities.  Even though community groups are not expected to build and maintain GIS applications, they must have the technological capacity to be informed partners and users of these systems. Building organizational and community capacity to use technology is a challenging endeavor.  In the Resources section there is information with links to help organizations navigate hardware and software purchases and training.

Step 5: Use Maps to Promote Neighborhood Revitalization.    back to top
The ultimate purpose of community mapping is to improve programs, policy, advocacy, and research.  Effective community groups will use GIS outputs and maps as a foundation for campaigns to promote equitable development.  In this step of the mapping process community organizations transform data and spatial analysis into action. In the Resources section are links to the organizations and campaigns profiled in the Why Use It section.  These projects illustrate the powerful connection between data and information and community change.