Web mapping is the process of designing, implementing, generating and delivering maps on the World Wide Web and its product. While web mapping primarily deals with technological issues, web cartography addition
A desktop GIS is a mapping application that is installed onto and runs on a personal computer and allows users to display, query, update, and analyze data about geographic locations and the information linked
Geographic Information System (GIS) is defined as an information system that is used to :
- retrieve ,
- manipulate ,
- analyze and
- output geographically referenced data or geographic data, in order to support decision making for planning and management of land use, natural recourses, environment, transportation, urban facilities, and other administrative records.
How Do We Describe Geographical Features?
by two 2 types of data:
-Spatial data which describes location (where)
-Attribute data which specifies characteristics at that location (what and how much) stored in a data base table
How Do We Represent These Digitally In A GIS?
by grouping into layers based on similar characteristics (e.g hydrography, elevation, water lines, sewer lines, grocery sales) and using either:
-Vector data model
-Raster data model
• Vector formats
-Discrete representations of reality
• Raster formats
-Use square cells to model reality