Geographical Data Sets
Geographic Data Types
Although the two terms, data and information, are often used indiscriminately, they both have a specific meaning. Data can be described as different observations, which are collected and stored. Information is that data, which is useful in answering queries or solving a problem. Digitizing a large number of maps provides a large amount of data after hours of painstaking works, but the data can only render useful information if it is used in analysis.
Spatial and Non-spatial data
Geographic data are organised in a geographic database. This database can be considered as a collection of spatially referenced data that acts as a model of reality. There are two important components of this geographic database: its geographic position and its attributes or properties. In other words, spatial data (where is it?) and attribute data (what is it?)
Attribute Data
The attributes refer to the properties of spatial entities. They are often referred to as non-spatial data since they do not in themselves represent location information.
| District Name | Area | Population |
| Noida | 395 sq. Km. | 6,75,341 |
| Ghaziabad | 385 sq. Km. | 2,57,086 |
| Mirzapur | 119 sq. Km. | 1,72,952 |
Spatial data
Geographic position refers to the fact that each feature has a location that must be specified in a unique way. To specify the position in an absolute way a coordinate system is used. For small areas, the simplest coordinate system is the regular square grid. For larger areas, certain approved cartographic projections are commonly used. Internationally there are many different coordinate systems in use.
Geographic object can be shown by FOUR type of representation viz., points, lines, areas, and continuous surfaces.
Point Data
Points are the simplest type of spatial data. They are-zero dimensional objects with only a position in space but no length.
Line Data
Lines (also termed segments or arcs) are one-dimensional spatial objects. Besides having a position in space, they also have a length.
Area Data
Areas (also termed polygons) are two-dimensional spatial objects with not only a position in space and a length but also a width (in other words they have an area).