What is a piezometer and what does it measure in hydrology?

What is a piezometer and what does it measure in hydrology?

• A. A device used to measure rainfall intensity.
• B. A device used to measure stream velocity.
• C. A device used to measure groundwater pressure or hydraulic head in aquifers.
• D. A device used to measure soil moisture.

Answer: (C)

A piezometer is a tube or small sensor installed into the ground to measure the pressure of groundwater, which is interpreted as hydraulic head in an aquifer. When you place a piezometer into the subsurface, the water column inside rises or falls to a height that represents the hydraulic head at that location. This head combines elevation head (the vertical position) and pressure head (the pore pressure within the water-filled pores), and comparing heads at different points reveals the groundwater gradient and flow direction. This is a fundamental way to characterize how groundwater moves through an aquifer and to assess conditions for pumping, contamination transport, or aquifer recharge. It isn’t used to measure rainfall intensity, which requires a rain gauge, nor stream velocity, which requires flow meters or tracer methods, nor soil moisture, which is measured with soil moisture probes or sensors.

A piezometer is a tube or small sensor installed into the ground to measure the pressure of groundwater, which is interpreted as hydraulic head in an aquifer. When you place a piezometer into the subsurface, the water column inside rises or falls to a height that represents the hydraulic head at that location. This head combines elevation head (the vertical position) and pressure head (the pore pressure within the water-filled pores), and comparing heads at different points reveals the groundwater gradient and flow direction. This is a fundamental way to characterize how groundwater moves through an aquifer and to assess conditions for pumping, contamination transport, or aquifer recharge.

It isn’t used to measure rainfall intensity, which requires a rain gauge, nor stream velocity, which requires flow meters or tracer methods, nor soil moisture, which is measured with soil moisture probes or sensors.