Subtopic: Measurement of infiltration, soil moisture and irrigation water infiltration
Question Statement:
In a double-ring cylinder infiltrometer test, the primary operational purpose of the outer concentric buffer ring is to:
Options:
(A) Prevent lateral flow divergence from the inner ring, forcing purely one-dimensional vertical infiltration below the inner measuring cylinder
(B) Provide a secondary storage reservoir to double the measured infiltration rate
(C) Prevent birds and small farm animals from drinking the water
(D) Measure the evaporation rate from the soil surface concurrently
Answer Key:
A
Step-by-Step Solution & Explanation
In a single ring, water seeps outward radially in three dimensions due to matric suction gradients at the edges, giving falsely high infiltration rates. In a double-ring infiltrometer, the outer annular space acts as a hydraulic buffer; lateral divergence occurs from the outer ring while infiltration below the inner measuring ring remains purely one-dimensional and vertical. Option A is correct.