Discharge measurement
The discharge measurement is a method of Hydrometrie in the hydrology . It shows the volume of water that has flowed through a certain river per time. The flow velocity and the imaginary cross-sectional area of the flowing water are usually measured, which when multiplied together produce the desired size.
Measurement method
There are different measuring methods, such as wing measurement, in which the flow speed is determined mechanically using water blades ( propeller or impeller ), on the other hand the tracer method , in which the concentration of tracers in the flowing water enables conclusions to be drawn about the flow speed. The measurement can also be carried out using an ultrasonic Doppler profile flow meter ( Acoustic Doppler Current Profiler (ADCP) ). This method measures the Doppler effect of the water moving towards the sensor and, when used correctly, is considered reliable and precise. Also , magnetic inductive flowmeters are used. They allow even greater precision, but not with water with a small mineral content. There is also the possibility of using so-called Thomson weirs . Here at, the amount of draining water is deduced from the height of the dammed water level.
See also
Web links
- Flow measurement - discharge measurement - OTT Hydromet Germany
- RQ-30d discharge measurement flow measurement
- Discharge measurement with moving bottom - LfU Bayern
- Planning of discharge measurements - UNITRACC - Underground Infrastructure Training and Competence Center
- Hydropower potential
- Report of the "Institute Water for Africa" association on cost-effective measurement methods for discharge measurement