GIS and Planning
A Geographic Information System, or GIS, is -- in the simplest terms -- computer mapping. GIS is a computer system that enables the collection, analysis, and visualization of information in a geographic context. It has cartographic tools for map production, to be sure, but it also uses data connected to geographic features to answer questions and reveal relationships. Features like utility poles, zoning boundaries, and building footprints are digitally represented by geometric objects such as points, lines, and polygons. These are given real-world coordinates, which means distances and locations are accurately represented. The attributes of a feature are stored in database tables that are linked to the geometric objects, and queries can reveal such things as how many people live within 1000 feet of a T station, or where buildings over 60 feet tall are located in the City, to give just two examples.
The base map data use by the City was derived from aerial photography commissioned in April 2010. Technicians then processed stereoscopic photographs to delineate and identify a slew of features visible on the ground, such as water bodies, pavement edges, buildings, and even park benches and crosswalks. Other data has been collected by City staff using GPS units to locate and identify items like street trees and bike racks. Legal descriptions or survey data provide the basis for invisible boundaries such as parcel lines and zoning district boundaries. All of this information can be analyzed in GIS, or organized with GIS for presentation on a map.
The planning information staff of the Community Development Department create and maintain GIS data related to public parks, playgrounds, and open space; zoning and zoning overlay districts; and demographic data drawn from the United States Census. CDD staff use maps to facilitate public meetings, illustrate neighborhood studies, and perform zoning and transportation analysis. There is hardly an aspect of civic life in Cambridge that does not have a geographic component to it, so GIS becomes an invaluable tool to support decision-making and problem-solving for City staff and citizens alike. GIS was used to create a gallery of maps on a number of more common subjects that can be accessed from the CDD website. GIS also powers the interactive maps within this website that allows users to pan, zoom, and select features in some of the datasets that are most relevant to the work of the Community Development Department.
Learn more about the Cambridge GIS.
For More Information
For more information about GIS at the Community Development Department and to learn more about the maps available on this web site contact Brendan Monroe at 617/349-4641 or firstname.lastname@example.org.