Question

In a Geographic Information System database, a stream is represented by a line and houses are represented by polygons. The pollution in the stream is affecting houses within a distance of 500 m on both sides. Which vector data analysis operations should be performed to identify houses affected by the pollution in the stream?

• A. Buffer and Overlay
• B. Dissolve and Overlay
• C. Buffer
• D. Split

Hint:

In GIS vector analysis, use the {Buffer} operation to define zones around features, and the {Overlay} operation to analyze spatial relationships between layers. This combination is especially useful for impact analysis.

Answer 1

The Correct Option is A

To identify the houses affected by pollution within 500 meters of the stream, two GIS vector operations are required:

1. Buffer: Create a 500 m buffer around the stream (line feature) to represent the impact zone of pollution.

2. Overlay: Perform an overlay (such as intersection) of the buffer zone with the polygons representing houses to extract only those houses that fall within the buffer area.

Hence, the correct combination of operations is Buffer and Overlay.