streamflow measurement

flow channel

A stream can be defined as a _____ into which the surface runoff from a specified basin drains.

Perennial Streams

Water flows in these streams throughout the year. The primary water source can be from ground water, surface water, or a combination of both.

Intermittent Streams

streams flow for part or most of the year but may carry no water during the dry season.

Ephemeral Streams

These streams flow only for a short time, usually after a large storm or snowmelt when there is an increase in water runoff.

Staff Gauge

The simplest of stage measurements are made by noting the elevation of the water surface in contact with a fixed graduated staff.

Wire Gauge

It is a gauge used to measure the water- surface elevation from above the surface such as from a bridge or similar structure.

Automatic Stage Recorders

The staff gauge and wire gauge described earlier are manual gauges.

Float-Gauge Recorder

is the most common type of automatic stage recorder in use.

Bubble Gauge

In this gauge, compressed air or gas is made to bleed out at a very small rate through an outlet placed at the bottom of the river

Volumetric and gravimetric method

It is the simplest and quickest method of determining the flow, thus may cause inaccuracies on flow measurement of large channels.

Slope-Area Method

This method is most used by civil engineers in the design of channels (canals and drainage systems).