Use of GIS at the LGA
Nonpoint Source Pollution Model
ESRI & LGA
The Geographic Information System at the Lake George Association enables us to produce sophisticated maps of Lake George and the Lake George watershed. These Lake George maps can show us Lake George land-use, personal property lines, roads, power-lines, census tracts, wetlands, forests, and much more.
What is GIS?
A Geographic Information System (GIS) is an automated system that enables a user to capture, store, integrate, manipulate, analyze, and display data that are spatially referenced to the Earth (a specific location). It is basically a high-tech electronic map that can be easily manipulated and added to, essentially taking the place of paper maps. Traditional cartographic paper maps are static, quickly become outdated, are expensive to update, and can only represent a single specific scale of spatial data per map. GIS gives the user the ability to view the data at different scales or zoom levels (e.g. Project Site or Watershed) and with different layers of information or datasets.
Geographic Information Systems use digital data that allows the user 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.
Project Site Scale (West Brook Conservation Initiative Location)
Data can be stored as:
- Points: Store locations, emergency phone locations, historic sites, or traffic lights
- Lines: Roads, trails, or power lines
- Polygons: 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, topographic maps or satellite imagery. Since the data are digital, they are easily transferred and shared with other GIS users.
Watershed Scale (West Brook Watershed)
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.
Putting The Software To Work
A GIS user can ask the system questions. Questions can vary in complexity beginning with something as simple as "Where is Jane Doe’s property located?" or "'What properties have an area greater than 500,000 acres?" to something much more complex like "What parcels have a forested land cover with over 10 acres of land and contain a wetland?" GIS prevents time-consuming manual searches of data sets and is a great way to manage the watershed. The possibilities are really just limited to the data that exist.