Irrigation Water Conveyance and Application Methods
Subtopic: Irrigation efficiencies
Question Statement:
In sprinkler irrigation evaluation, Christiansen's Uniformity Coefficient ($CU$) is computed from catch can depths as $CU = 100\left[ 1 - \frac{\sum |x_i - \bar{x}|}{n \bar{x}} \right]$. A sprinkler system is generally considered to achieve an acceptable standard of water distribution uniformity when $CU$ is at least:
Options:
(A) $80.0\%$
(B) $50.0\%$
(C) $30.0\%$
(D) $99.9\%$
Answer Key:
A
Step-by-Step Solution & Explanation
In agricultural sprinkler engineering practice, a Christiansen Uniformity Coefficient ($CU$) of $\ge 80\%$ is considered acceptable for commercial field crops, and $\ge 85 - 90\%$ for high-value horticultural crops. Option A is correct.