Which device is used to measure infiltration rates in the vadose zone?

Which device is used to measure infiltration rates in the vadose zone?

• A. Tensiometer
• B. Infiltrometer
• C. Piezometer
• D. Seismograph

Answer: (B)

Measuring how fast water enters soil in the unsaturated vadose zone is done most directly with an infiltrometer. This device releases water at the soil surface and tracks how the infiltration depth changes over time, allowing you to calculate the infiltration rate. A double-ring infiltrometer helps minimize lateral water flow, so the measurement reflects vertical movement into the soil rather than sideways spread. Tensiometers, by contrast, gauge soil water potential (matric suction) rather than the rate at which water moves into the soil. Piezometers monitor pore-water pressure in the saturated zone, and seismographs measure ground vibrations—neither provides a direct infiltration rate. So the infiltrometer is the appropriate tool for this measurement.

Measuring how fast water enters soil in the unsaturated vadose zone is done most directly with an infiltrometer. This device releases water at the soil surface and tracks how the infiltration depth changes over time, allowing you to calculate the infiltration rate. A double-ring infiltrometer helps minimize lateral water flow, so the measurement reflects vertical movement into the soil rather than sideways spread. Tensiometers, by contrast, gauge soil water potential (matric suction) rather than the rate at which water moves into the soil. Piezometers monitor pore-water pressure in the saturated zone, and seismographs measure ground vibrations—neither provides a direct infiltration rate. So the infiltrometer is the appropriate tool for this measurement.