Attribute Data

Definition

Attribute data in Geographic Information Systems (GIS) refers to the additional information about spatial features that is stored in a tabular format and linked to spatial data. This type of data, also known as non-spatial data, is the descriptive information or characteristics of spatial data that give it greater depth and context. Attribute data enriches the spatial data as users not only know the location of events or features, but also the properties of those events or features.

Attributes can be of different types, including categorical (e.g., land use type), numerical (e.g., population), or binary (e.g., presence or absence of a certain characteristic). This dataset is usually stored in a database where each row represents a geographic feature and each column represents a particular attribute of the features.

What is Attribute Data?

Attribute data in GIS are the details that describe the properties and characteristics of spatial features. These spatial features could be points, lines, or polygons that represent real-world phenomena on a map. For example, in a GIS application, a point on a map may represent a location of a school. This point would have attribute data associated with it that details information about the school, such as the school name, type of school (elementary, high school, etc.), number of students, and so on.

In a table of attribute data, each spatial feature is assigned a row, and each attribute of the feature is assigned a column. Therefore, the attribute data table provides more than just the "where"; it also provides the "what," "how," and "why" that enhances our understanding of the spatial data.

FAQs

What is the role of attribute data in GIS?

Attribute data is vital in GIS because it provides additional information or context to the locational data, enabling users to make informed decisions. It enhances spatial data by detailing and explaining more about the specific features represented on a map.

How is attribute data created and stored in GIS?

Attribute data is often created by specialists who collect data in the field or from various secondary sources like censuses or surveys. Once collected, this data is stored in a relational database where it is linked to the spatial data, usually via a unique ID or 'primary key'.

What are some examples of attribute data?

Some examples of attribute data include descriptive information like name, color, type, height, area, population, density, and any other characteristic that can be associated with the geographic feature.

What are the different types of attribute data in GIS?

Attribute data in GIS can be classified into nominal (categorical), ordinal (rankings), interval (measurements), and ratio (counts). Nominal data typically includes names or labels. Ordinal data involves some sort of ranking. Interval data includes measurements where the range matters. Ratio data includes counts and often involves rates or multiples.