GIS and spatial data

Define GIS?

GIS as a system stores geographic information in layers and integrated with geographic software programs so that spatial information can be created, stored, manipulated, analyzed, and visualized (mapped). 

Define spatial Data?

Spatial data uses data that include a geographic component to it. The records in a dataset have locational information tied to them such as geographic data in the form of coordinates, address, city, or ZIP code. GIS data is a form of geospatial data.  Other geospatial data can originate from GPS data, satellite imagery, and geotagging.

Data with a spatial component refers to Geospatial data. Vector or raster data are the two types of geospatial data available.

Vector data format
Datasets with specific coordinates are represented as points, lines, or polygon features in vector data. Because point data reflects a place in space, it is commonly referred to as “location data.” Lines refer to features with a length or distance, such as rivers and highways, whereas polygons refer to features having an area. Regions such as parcels, cities, woods, states, and countries are represented by polygons.

Raster data format
Rasters, also known as coverages, grids, pixels are images with a geographic location assigned to its edges. Because rasters are made up of pixels, they indicate average values within the area covered by the pixel, whereas vector data is explicit. Rasters are commonly used in GIS to display elevation, satellite pictures, or scanned paper maps with geographic extents.

GIS data types

GIS data is categorized into spatially referenced data known as vector and raster forms (including imagery) and attribute tables which are represented in tabular format. 

GIS and Spatial data relationship

In order to develop local and regional relationships to understand the nature of the Earth, geoscientists work with spatial data. GIS has added to our capabilities, but spatial relationships in geoscience predate our modern concept of a GIS system (e.g. computers, software, digital data, etc.) through geological, topographic, and other maps with spatial data. The content for a class is derived using GIS as a tool. GIS methods create the materials and are also involved in the student learning experience