SSC IMD SA 2017 – Question 171

Which of the following statements is true regarding a ‘discrete field’?

• Discrete fields divide the study space into mutually exclusive, bounded parts, with all locations within one part having the same value
• ‘Land classification’ is an example of discrete fields
• Discrete fields use ‘boundary’ features
• All options are correct

Detailed Explanation:

The correct answer is d) All options are correct (सभी विकल्प सही हैं).

In Geographic Information Systems (GIS) and spatial data modeling, geographic phenomena across a surface are conceptualized either as continuous fields or discrete fields:

• Partitioning of Study Space: A discrete field (also known as a categorical coverage or categorical field) divides geographic space into distinct, mutually exclusive, and contiguous bounded regions (polygons). Every location within a given region is assigned the exact same attribute value or class label.
• Land Classification as a Prime Example: Land use and land cover (LULC) maps, soil classification maps, geological units, and administrative zoning districts are classic examples of discrete fields. For instance, a polygon classified as ‘Forest’ or ‘Urban’ represents an area where that specific category applies homogeneously.
• Use of Boundary Features: Discrete fields rely on defined boundaries (edges or perimeters) to separate one homogeneous zone from another, unlike continuous fields (such as elevation, temperature, or air pressure) where attribute values transition smoothly and continuously without abrupt borders.

Because all three statements (a, b, and c) accurately characterize discrete fields, option d is the correct choice.