In the FAO-56 Penman-Monteith method, the reference crop evapotranspiration ($ET_0$) is defined for a hypothetical reference surface with an assumed height of:
Options:
(A) $0.12\text{ m}$ (tall fescue/grass)
(B) $0.50\text{ m}$ (alfalfa)
(C) $1.0\text{ m}$ (wheat)
(D) $2.0\text{ m}$ (maize)
Answer Key:
A
Step-by-Step Solution & Explanation
The FAO-56 Penman-Monteith reference surface is an idealized hypothetical grass reference crop with an assumed height of $0.12\text{ m}$, a fixed surface resistance of $70\text{ s/m}$, and an albedo of $0.23$.