Ayacut is the area intended or served under an irrigation source in official usage. A project page may list designed command, potential created, potential utilised and actually irrigated area separately. These numbers should not be conflated. Water availability, canal condition, seasonal rainfall and cropping decisions affect actual use. A hectare count from one year cannot be carried into every subsequent year as if it were a fixed physical feature.
Krishna district's irrigation-circle page lists ayacut for different works, illustrating how multiple sources overlap a district's farm economy. For a basic exam, understand that a reservoir is infrastructure and ayacut is a land-service measure. “One project has a large ayacut” does not prove every hectare grew paddy or that water arrived in every season. The map point for the headwork and the much larger command area are different geometries.
Worked example: An irrigation project announces 100,000 hectares of planned ayacut. If only part receives water this season, the planned command and actual irrigated crop area differ. To compute coverage, use the same season and units for numerator and denominator. A canal running through a district is not proof that every hectare of that district is in the project command.
Active recall: Which is an area measure: reservoir, canal or ayacut? Why might actual irrigation be smaller than design potential?