debiet

Debiet is a term used in hydrology, hydraulics and related fields to describe the rate at which a fluid passes through a given cross-section. It represents the volume of fluid transiting a point per unit of time and is typically denoted by the symbol Q. Debiet can be instantaneous, measured at a specific moment, or averaged over a time interval.

In open channels and closed conduits, debiet is commonly estimated as the product of cross-sectional area A and the mean fluid velocity v, i.e., Q = v · A for uniform flow. For non-uniform or complex flow, more advanced methods or depth- and velocity-profile integrations may be required. Because the fluid may be incompressible or nearly so, debiet calculations often rely on continuity and, where applicable, energy or momentum principles.

Common units are cubic meters per second (m^3/s) in the International System of Units, with liters per second (L/s) or cubic meters per hour (m^3/h) also in use for practical measurements. Debiet is a central concept in river discharge, flood forecasting, irrigation planning, water-resource management and the design and operation of water-supply networks, drainage systems and industrial piping.

In physiology, the term is also used to describe the cardiac output—the volume of blood the heart pumps per minute—often referred to as the hartdebiet in Dutch.

Measurement methods include weirs and flumes for open-channel flows, and electromagnetic, ultrasonic, venturi and other flow meters for closed systems. Accurate estimation of debiet requires appropriate instrumentation, calibration, and consideration of fluid properties, turbulence and system geometry.