Attribute data

Also called: Non-spatial data · Topic: Remote Sensing, GIS and GNSS · NCERT: Class 12, Ch 4 "Spatial Information Technology"

Meaning

Attribute data (also called non-spatial data) is descriptive information about a feature: what it is, what it is like, or how much of it there is. It has no location of its own. A cycle shop's stock register (models, prices, quantities) is the NCERT example. A GIS (geographic information system: a computer system that stores, combines and analyses data linked to places) keeps attribute data in tables. It links each row to a point, line or area on the map.

It matters because location alone tells you only where something is. Attribute data tells you what is there. Only when the two are joined can a planner ask why it is there and what if it changes.

Explanation

Two forms of geographical information

• Spatial data: data tied to a location and registered to a coordinate system (a fixed grid of latitude–longitude or map coordinates). Examples are the outline (polygon) of a state, the line of a river and the point of a well.
• Attribute (non-spatial) data: the description that goes with a feature. Examples:
• a road's name, width, surface type and traffic
• a district's population or literacy figure

• a well's depth or water quality

• NCERT Box 4.1:

• a cycle shop's stock register is non-spatial, because its rows do not refer to places
• state-wise literacy rates are spatial, because each row belongs to a state that can be found on the map.

How a GIS joins the two

• Step 1: store the shape. Each real-world object is stored as a point (well, bus stop), a line (road, canal) or an area/polygon (lake, district).
• Step 2: store the description. The attributes sit in a table of rows and columns. Each row stands for one feature.
• Step 3: link them. A shared ID or location code (for example, a district code) connects each table row to its map feature.
• Result: the polygon of a state (spatial) is joined to its literacy figure (attribute). Now the data can be analysed, not just drawn.

What attribute data makes possible

• Query a feature: click a district and see its population.
• Draw maps from attribute queries: for example, "show all districts with literacy below 60%". The map is drawn from the table.
• Join tables: link Census data and health data through a common district code.
• Re-display without redrawing: a paper map fixes one theme and one look. A GIS keeps data separate from display, so the same attributes can be shown in many colours, classes and scales.

Where it sits in the system

• DBMS (database management system: software that stores and processes data in tables) is the tool that manages attribute tables in spatial information technology.
• A DBMS on its own knows "what" but not "where". GIS adds the "where".
• Under the data component of GIS, data are both spatial and tabular (attribute). Data are called the backbone of GIS.
• Attribute data are typed in and edited through the data entry and editing software module. They are used in the analysis module and shown through the display and output module (maps, tables, reports).

Where it occurs

• Indian Census and planning: Census tables (population, literacy) are linked to district and state boundaries through district codes. Health data can be joined to the same districts.
• Bhuvan (ISRO's geoportal, run by NRSC, Hyderabad): its Thematic mode gives natural-resource layers made by NRSC with State Remote Sensing Applications Centres. Each layer carries descriptive classes linked to map areas [5]. Government departments host their own applications on it [4].
• Geospatial governance: Bhuvan runs about 150 web services that departments use to govern with the help of maps and their linked data [5].
• Everyday GIS layers anywhere in the world: roads (name, width, surface), rivers (name, length), wells (depth), land-use parcels (owner, crop). The shape is spatial and the description is attribute data.
• Sources of the data: buying digital data (for example from Survey of India or Bhuvan), digitising (converting into computer form) paper maps, or carrying out your own surveys. Ground surveys often collect the attributes, while GPS fixes the position.

Don't confuse with

• Spatial data: this is registered to a coordinate system and has a location. Attribute data only describes a feature and has no location of its own.
• A table that is linked to places: the same kind of table becomes spatial once each row is tied to a place. State-wise literacy is spatial because "Kerala" or "Bihar" can be found on a map. A shop's stock register is not.
• DBMS vs GIS: a DBMS manages attribute tables but cannot answer "where". A GIS links those tables to map features and analyses them.
• Feature type (point/line/polygon): this is the shape used to store an object, which is spatial. The road's width or the lake's depth is the attribute.

Prelims Hooks

• NCERT Box 4.1: a cycle shop's stock register is non-spatial. State-wise literacy rates are spatial. This is a common "which of the following" trap.
• Attribute data = non-spatial data = descriptive, tabular data that a GIS links to point, line or area features.
• The DBMS is the part of spatial information technology that manages tables of descriptive data.
• The data component of GIS includes both spatial and tabular (attribute) data. Data are called the backbone of GIS.
• "Show all districts with literacy below 60%" is an example of drawing a map from an attribute query, which a paper map cannot do.
• Two tables (for example Census and health) are joined through a shared location code, such as a district code.

Mains Points

• Turning tables into decisions (GS-I/GS-III):
• When attribute tables such as Census, health or land-use data are linked to map features, planners can query, filter and map them at once.

• This supports targeting, such as finding low-literacy districts, and "what if" analysis in urban planning and disaster management.

• Open data multiplies the value of attributes: the National Geospatial Policy 2022 opened up geospatial datasets made with public funds [3]. It also replaced security clearance with self-certification [2]. Together with Bhuvan's free data [4], this lets states, start-ups and researchers attach their own attribute data to standard base maps.

• Quality gaps remain: attribute data are only as good as the people and procedures behind them. Data standards differ between agencies, digitised records vary in quality and trained GIS staff are scarce. Mismatched codes and descriptions weaken analysis even when the maps are accurate.

Related concepts

• Database management system
• Computer assisted cartography
• Spatial information technology
• Geographic information system
• Spatial data
• Point, line and area features
• Advantages of GIS over manual maps
• Components of GIS

Read more

• Spatial information technology and GIS: concepts and components