The GATE Grind

GATE 2022 CE (CE1) – Question 20

Hydrology · Hydrologic cycle, precipitation, evaporation, evapo-transpiration, infiltration · 1 mark · Multiple choice

Let $\psi$ represent soil suction head and K hydraulic conductivity. If moisture content $\theta$ increases, which statement is TRUE?

  1. $\psi$ decreases and K increases
  2. $\psi$ increases and K decreases
  3. Both $\psi$ and K decrease
  4. Both $\psi$ and K increase

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Correct answer: (A) $\psi$ decreases and K increases

Explanation

Increasing water content makes an unsaturated soil wetter, reducing capillary suction. It also connects more water-filled pores, increasing hydraulic conductivity toward its saturated value.

Thus **suction decreases and conductivity increases**, **A**.