Geographic Information Systems store, examine and visualize data for geographic location on Earth’s surface. GIS is a computer-based device that studies spatial relationships, patterns and trends. By joining geography with data, GIS better understands data using a geographic context.
GIS presents the capability to relate formerly unrelated information, through the use of location as the “key index variable”. Locations and extents that are constructed in the Earth’s spacetime, are able to be recorded through the date and time of occurrence. Along with x, y, and z coordinates; symbolizing , longitude (x), latitude (y), and elevation (z). This main characteristic of GIS, has started to open new avenues of scientific inquiry and studies.
The 4 main concepts of Geographic Information Systems (GIS) are:
- Create geographic data.
- Manage it in a database.
- Analyze and find patterns.
- Picture it on a map.
We use Geographic Information Systems for:
- Pinpointing new store locations
- Reporting power outages
- Analyzing crime patterns
- Routing in car navigation
- Forecasting and predicting weather
Components of Geographic Information Systems
The three major constituents of Geographic Information Systems are:
- DATA: GIS saves location data as thematic layers. Each data set has an attribute table that saves information about the component. The two major types of GIS data are raster and vector:
Raster resembles grids because they save data in rows and columns. They can be discrete or continuous. For example, we generally represent land cover, temperature data and imagery as raster data.
Vectors are points, lines and polygons with vertices. For example, fire hydrants, contours and administrative boundaries are generally vectors.
- HARDWARE: Hardware controls GIS software. It can be anything from powerful servers, mobile phones or a personal GIS workstation. The CPU is workhorse and data processing is the term of the game. Dual monitors, extra storage and crisp graphic processing cards are necessary to have in GIS.
- SOFTWARE: ArcGIS and QGIS are the chiefs in GIS software. GIS software specialize in spatial analysis by using math in maps. It mixes geography with modern technology to evaluate, quantify and understand our world.
Geoprocessing is a Geographic Information Systems operation device to manipulate spatial data. A typical geoprocessing operation accepts an input dataset, performs an operation on that dataset, and returns the result of the operation as an output dataset.
Basic geoprocessing operations include:
- geographic trait overlay,
- feature selection and analysis,
- topology processing,
- raster processing,
- data conversion.
Geoprocessing grants for definition, management, and analysis of information used to form decisions.
Geographic Information Systems data shows real objects (such as roads, land use, elevation, trees, waterways, etc.) with digital data determining the mix. Real objects are split into two abstractions: discrete objects (e.g., a house) and continuous fields (such as rainfall amount, or elevations). Commonly, there are two broad methods used to store data in a GIS for kinds of abstractions mapping references: raster images and vectors. Points, lines, and polygons are the objects of mapped location attribute references. A modern hybrid method of storing data is that of identifying point clouds. It combines three-dimensional points with RGB information at each point, returning a “3D colour image”. GIS thematic maps are gradually becoming more and more realistically visually descriptive of what they set out to show or determine.
Geostatistics is a branch of statistics that is concerned with field data, spatial data with a continuous index. It grants methods to model spatial correlation, and predict values at arbitrary locations (interpolation).
When phenomena are evaluated, the observation methods govern the accuracy of any subsequent analysis. Due to the nature of the data (e.g. traffic patterns in an urban environment; weather patterns over the Pacific Ocean), a constant or dynamic degree of attention is always gone in the measurement. This failure of precision is determined from the scale and distribution of the data collection.
Geographic Information Systems careers are booming for:
- CARTOGRAPHERS prepare maps. In fact, the source of “cartographer” comes from charta which signifies “tablet or leaf of paper” and graph “to draw”
- DATABASE MANAGERS store and collect information from structured sets into spatial databases.
- REMOTE SENSING SPECIALISTS use aerial, satellite imagery and remote sensing software.
- SPATIAL ANALYSTS use geoprocessing tools to change, extract, locate and analyze geographic data.
- LAND SURVEYORS measure the 3-dimensional coordinates on the land.