Question

Water distribution efficiency has got identical similarity with that of:

• A. Friction Coefficient
• B. Runoff Coefficient
• C. Uniformity Coefficient
• D. Drainage Coefficient

Hint:

Water distribution efficiency evaluates how evenly water is distributed along the irrigation run.
A value above 85% is generally considered excellent for surface irrigation systems.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Water distribution efficiency measures how uniformly water is applied across an irrigated field.
A high water distribution efficiency indicates that water has penetrated to a consistent depth throughout the root zone, ensuring uniform crop growth and minimizing deep percolation or underwatered patches.
Key Formula or Approach:
The water distribution efficiency (\( \eta_d \)) is calculated using the following equation:
\[ \eta_d = \left( 1 - \frac{y}{d} \right) \times 100 \] where:
\( d \) is the average depth of water stored along the run during irrigation.
\( y \) is the average numerical deviation from \( d \).

Step 2: Detailed Explanation:
This formulation is mathematically identical to Christiansen's Uniformity Coefficient, which is used to evaluate sprinkler systems.
Christiansen's Uniformity Coefficient (\( C_u \)) is expressed as:
\[ C_u = \left( 1 - \frac{\sum |x_i - \bar{x}|}{n \cdot \bar{x}} \right) \times 100 \] where:
\( x_i \) is the individual water catch in a can.
\( \bar{x} \) is the mean catch.
\( n \) is the number of catch cans.
Both parameters evaluate the deviation of water depth from the mean value to quantify application uniformity.
Friction coefficient is a fluid flow parameter.
Runoff coefficient is used in hydrology to estimate the peak discharge.
Drainage coefficient refers to the depth of water removed from an area in 24 hours.

Step 3: Final Answer:
Water distribution efficiency is conceptually and mathematically identical to the Uniformity Coefficient.