Are Doppler radar flowmeters accurate in sediment-laden rivers?

Yes, it stays accurate. A Doppler radar flowmeter measures non-contact: the radar beam is reflected from above the water surface and never touches the flow, so sediment, suspended solids and weeds do not enter the measurement chain. This avoids the problem of ultrasonic instruments, whose acoustic signal is scattered by suspended particles in the water.

The HZ-KSLF multi-band Doppler radar flowmeter has been used on Yellow River irrigation main canals, high-turbidity tailwater and debris-flow channels. Surface velocity is derived from the microwave return of surface micro-roughness; turbidity does not degrade the signal, and because the device is mounted above the channel it cannot be buried by silt or worn by abrasive flow.

• Sediment, floating debris and weeds do not affect measurement — no cleaning maintenance
• A wide range of 0.03-15 m/s handles the velocity swings of sediment-laden flow
• With EC32/EC60 series RTUs and solar power, suited to long-term unmanned field deployment

One boundary case to note: heavily aerated flow (rapids, drop structures) degrades the return signal, so cross-check against a stage-discharge rating curve at those sites. For more information, please visit our product pages or contact our technical team.