Geographic Information Systems (GIS)

What is GIS?
A Geographic Information System (GIS) is an automated system that enables a user or analyst to capture, store, integrate, manipulate, analyze and display data that are spatially referenced to the Earth. It can be best described as a high-tech map that replaces traditional cartographic methods which are static, expensive to update, and can only represent one level or specific scale of spatial data per map.

Digital Data
Geographic Information Systems use digital data that allow the analyst to easily create maps with many different layers or themes at any scale desired. The scale can be changed from 1:24000 to 1:10000. By changing the scale of your final map, you are not changing the scale that the original data was collected at, you are only changing the scale of the map that you are producing.

Data can be stored as:

Points: Store locations, emergency phone locations, historic sites, or traffic lights
Lines (vectors): Roads, trails, or power lines
Polygons (regions): A country, lake, watershed, or even the extent of a milfoil site.

All of this data can be layered on top of raster images such as aerial photography or satellite imagery. Since the data are digital, they are easily transferred and shared with other GIS users.

The Power Of GIS
GIS is more than a mapmaking tool. Its real power lies in its ability to query the associated database that is attached to the points, lines, and polygons of geographic information. The information on the map is displayed in many different layers. Each layer has information stored in fields within the database. The fields contain the geographic location of the points, lines, or polygons as well as information that may be useful to scientists, city planners, or market researchers. The information is spatially referenced to the Earth, allowing many different data layers to be queried for one specific location all at one time.

GIS & The LGA
The Lake George Association is currently utilizing GIS to produce maps, query data, as well as produce models to simulate the real world.

Maps
The LGA uses GIS to produce maps of all sizes and scales. Most of the maps relate to property locations. For example, GIS would enable the LGA to make a map for a member who wanted to see where their property is located in relation to a proposed construction site or to determine if a re-zoning area is within the watershed. Maps are also created for consultants working on Lake-Saving Projects. The maps are used to identify property owners along stream paths or nearby project sites so that the nearby owners can be well informed of problems and solutions recommended in that area.

Putting The Software To Work
GIS is also used to query data. In other words, a GIS user can ask the system questions. Some questions may be: Where is Jane Doe’s property located? What properties have an area greater than 500,000 Acres? Which properties have contact with a particular brook?

The major advantage here is that the database works for the user, preventing time-consuming manual searches of the database.

The Real World
LGA is attempting to use GIS as a model to simulate the real world. This is a powerful use of GIS and one that LGA would like to do more of in the future. We are currently working on creating a Non-Point Source Pollution Model in conjunction with the Department of State (Division of Coastal Resources). This model will allow us to find areas with high runoff potential and help us to determine locations that might be in need of renovation. Once identified, solutions can be proposed that may help to alleviate such problems as phosphorous loadings in the lake. Other types of models are also being considered that can monitor and project the Basin’s development ensuring that Lake George remains the “Queen of American Lakes”.

For more information on GIS please contact the LGA.

Other articles of interest are listed below. Click on the coordinating name to view the article.

November 2000 LGA News “What is GIS?” Page 1
December 2000 LGA News “LGA Utilizes the Power of Geographic Information Systems” Page 3
Click here to view the Project Maps