---
title: "GCA, CCA, NCA, intensity and pattern"
subject: "Irrigation and Drainage Engineering"
chapter: 1
key: "semester_6/irrigation_and_drainage_engineering:gca-cca-nca-intensity-pattern"
source: https://www.bctengineer.com/q/semester_6/irrigation_and_drainage_engineering/gca-cca-nca-intensity-pattern
site: BCT Engineering
---

# GCA, CCA, NCA, intensity and pattern

Irrigation and Drainage Engineering · Chapter 1: Introduction

- Asked in: 2075 Baisakh, 5 marks; 2070 Chaitra (old course), 8 marks; 2063 Asoj (old course), 8 marks; 2074 Bhadra, 2 marks (asked 4 times)
- Answer checked by Claude Opus 5.5 (high effort) on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_6/irrigation_and_drainage_engineering/gca-cca-nca-intensity-pattern
- Whole chapter: https://www.bctengineer.com/md/semester_6/irrigation_and_drainage_engineering/chapter-1

## Question

Explain GCA, CCA, NCA, cropping intensity and cropping pattern.

## Short answer

GCA is total area enclosed by canal command; CCA is cultivable portion of GCA; NCA is area actually cropped in a season. Cropping intensity is the percentage of net sown area cropped in a year (e.g., 180% for two crops), while cropping pattern is the yearly crop sequence like rice-wheat.

## Answer

#### Gross Command Area (GCA)
The total area enclosed within the boundary of a canal command, including cultivable land, roads, villages, ponds, forests and barren land. It is the area that can be commanded by the canal by gravity.

#### Culturable Command Area (CCA)
The part of GCA that is fit for cultivation. CCA = GCA - unculturable area (settlements, rock, water bodies, roads). CCA is the area used for design.

#### Net Culturable (Cropped) Area (NCA)
The area actually cropped or irrigated in a season. It excludes land kept fallow and is less than or equal to CCA. For a single season, the irrigated area is the part of CCA that actually receives water.

$$
GCA \ge CCA \ge NCA
$$

CCA is often about 75-85% of GCA.

#### Cropping intensity
The percentage of the net sown area that is cropped in a year, counting each crop separately (a field with two crops in a year has 200%).

$$
\text{Cropping intensity}=\frac{\text{Gross cropped area}}{\text{Net sown area}}\times 100
$$

#### Irrigation intensity
The percentage of CCA irrigated in a season (e.g. 60% of CCA in kharif).

#### Cropping pattern
The yearly sequence and spatial arrangement of crops on a farm or in the command area, e.g. rice-wheat-fallow, rice-wheat-maize or rice-mustard-maize. It depends on climate, soil, water, market and the farmers' preference.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What does Gross Command Area (GCA) include?
   A. The whole area within the canal command including roads, villages, ponds and barren land
   B. Only the land actually cropped
   C. Only land fit for cultivation
   D. Only the area irrigated this season
   Answer: A. GCA is the total area that could be commanded by gravity, including unculturable portions. (Key point: GCA definition)

2. How is CCA obtained from GCA?
   A. CCA = GCA + fallow area
   B. CCA = GCA - unculturable area
   C. CCA = NCA x cropping intensity
   D. CCA = GCA / 2
   Answer: B. CCA is the culturable part of GCA and is used for design. (Key point: CCA)

3. Which order is correct?
   A. NCA > CCA > GCA
   B. CCA > GCA > NCA
   C. GCA > CCA > NCA
   D. GCA < CCA < NCA
   Answer: C. Each area is a subset of the previous one, from total command down to the area actually cropped. (Key point: Order of areas)

4. A field with two crops in a year has what cropping intensity (single net sown area)?
   A. 100%
   B. 50%
   C. 20%
   D. 200%
   Answer: D. Cropping intensity = gross cropped area / net sown area x 100, counting each crop. (Key point: Cropping intensity)

## Related in Irrigation and Drainage Engineering

- [Cropping intensity and irrigation intensity](https://www.bctengineer.com/question.md?key=semester_6%2Firrigation_and_drainage_engineering%3Acropping-irrigation-intensity) — Irrigation and Drainage Engineering, chapter 1, asked 2×

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