A GIS is a computerized system for input, storage, management, display and analysis of data that can be precisely linked to a geographic location. GIS is both a database system with specific capabilities for spatially referenced data, as well as a set of operations for working with the data. GIS makes it possible to link or integrate information that is difficult to associate through any other means. Data can be linked with a particular point on the earth, such as an address or a monitoring well, or can be aggregated to a specific level of analysis, such as a watershed, town, or user-defined area. By incorporating geography into an investigation, trends and patterns are revealed that were not previously apparent. The power of GIS lies in its ability to incorporate and analyze both geographical and non-geographical data from a variety of sources and formats. GIS capabilities can augment existing services, as well as offer new, innovative solutions to ERL’s clients. Composite mapping and 3D visualization capabilities are effective in making results clear and understandable.

GIS allows for easy data access and management allowing users to formulate specific queries such as where are my customers located? Using combinations of mapped variables the data then can be used in further analyses to answer questions such as "How many customers live within a 5-mile radius of my store?" or "Where is the ideal site for a telecommunication tower?" This ability to examine relationships between multiple layers of the same geographic region is an important display feature of GIS. For example, GIS can simultaneously display neighborhood boundaries, streets, bus routes, and healthcare facilities for a community. The overlay function also facilitates the adding, or aggregation, of point data within geographic subdividions. For example, the number of asthma cases can be determined by community health district.

The following areas are among those services provided by ERL’s GIS department:

Monitoring, Managing & Mapping Databases
GIS offers the ability to visualize environmental contamination data in relation to current and historical land use, soil classifications, known tank locations, spill locations, watersheds, wetlands, water bodies, and aerial photographs.

View Shed Analysis / Line of Sight
Using digital elevation models (DEM's) and parcel level data we can determine what can and can’t be seen from a particular location.

GIS Healthcare Applications
**NEW** View GIS Solutions For Healthcare Newsletter

The potential for GIS to benefit the healthcare industry is just now beginning to be realized. Both public and private sectors are developing innovative ways to harness the data integration and spatial visualization of this technology. GIS plays a critical role in determining where and when to intervene, improving the quality of care, increasing accessibility to services and preserving patient confidentiality while satisfying the needs of the research community for data accessibility (Davenhill 1999). Recent advances in geographic information and mapping technologies have created new opportunities for healthcare administrators to enhance their planning, management and monitoring capabilities. These technologies can help planners better assess and analyze the spatial relationships of factors and potential constraints in the implementation of healthcare programs.

Demographic Marketing Tools
With a couple of clicks of a mouse - the GIS can display a detailed geographic and demographic view of community characteristics. Providing healthcare services and effective marketing both require an understanding of the community. GIS offers geographic solutions to improve strategic planning and marketing decisions that affect the delivery of healthcare services. This technology allows strategists to accurately visualize spatial pattens for demand and utilization. Understanding the distribution of the patients, facilities, and the underlying population enables admisinstrators to make informed and effective decisions. Identifing concentrations of specific sub-populations, such as seniors (see graphic) or newborns, can improve the dissemination of funding, staffing, and information.

Strategic Planning - Decision Support
As an emerging trend in healthcare planning GIS allows administrators to retain a competitive edge by determining who their patients are, what their health needs are, and where they are located. Combining traditional administrative data, such as hospital discharge data and billing information with socio-demographic data available through the US Census Bureau, improves the capability of decision-makers to evaluate the needs of the population. Allocating resources is a critical component of any business and in healthcare, it's even more critical. By tracking the locations of people, places, and things, resources can be deployed more effectively.

Disease and Injury Mapping
Mapping out disease and injury patterns enables users to identify areas where incidents of specific conditions such as asthma are higher than others. Patient location can be cross tabulated with age, race, sex, ICD-9 codes to determine where to target new facilities. For example, geographic analysis can identify communities and neighborhoods with growing numbers of foreign born women which indicate areas where the need for multi-lingual women’s services may be needed.

Emergency Response Mapping
If a catastrophic event was to occur, pre-planning could have produced a geographic analysis which could have been used to determine the number of, and distance to, all major hospitals. It could identify the closest emergency response teams, as well as calculate the density and characteristics of the affected population. City-wide (region-wide, county-wide, etc.) response plans developed using GIS capabilities could expedite appropriate response and optimize the services available.