Table of Contents
How is streamflow discharge measured?
discharge = area x velocity The most common method used by the USGS for measuring velocity is with a current meter. However, a variety of advanced equipment can also be used to sense stage and measure streamflow. In the simplest method, a current meter turns with the flow of the river or stream.
What unit is streamflow measured in?
cubic feet per seconds
It is most commonly expressed in cubic feet per seconds or gallons per day. To calculate discharge, multiply the area of water in a channel cross section by the average velocity of water in that cross section.
What is unit for rate of flow discharge?
Flow rate or discharge, Q, is the volume of water in cubic feet passing a flow section per unit time, usually measured in cubic feet per second (ft3/s).
Which method is used for discharge measurement?
Stream discharge can be measured using (1) volumetric gauging, (2) float gauging, (3) current metering, (4) dilution gauging (constant injection or gulp methods), (5) structural methods, and (6) slope-area methods. The choice of method depends on the characteristics of the stream and on the application.
Why do we measure streamflow?
Streamflow information is required to determine how much water is available in different locations so the citizens can make informed decisions about growth and to help assure there is an adequate water supply even during periods of drought.
What is discharge measurement?
Discharge measurement requires determining the mean velocity in each of the selected verticals. The mean velocity in a vertical cross section can be approximated by making several velocity observations at different depths and then using a known relationship between these velocities and the vertical mean velocity.
How is discharge rate calculated?
In this case, the discharge rate is given by the battery capacity (in Ah) divided by the number of hours it takes to charge/discharge the battery. For example, a battery capacity of 500 Ah that is theoretically discharged to its cut-off voltage in 20 hours will have a discharge rate of 500 Ah/20 h = 25 A.
What is stream discharge?
Stream flow, or discharge, is the volume of water that moves over a designated point over a fixed period of time. It is often expressed as cubic feet per second (ft3/sec).
Why is measuring discharge important?
This is one reason for measuring flow – to work out the load of contaminants and sediment the waterway is carrying. Because discharge can have a significant effect on water quality, it is important that it is recorded at the time of sampling and, if possible, during the previous few days.
What device measures discharge?
Venturimeter is a discharge measurement instrument that uses a converging section of pipe to give an increase in the flow velocity and a corresponding pressure drop from which the flowrate can be deduced.
How do you calculate discharge units?
Total Discharge Units Calculator
- Total Discharge Units = SUM(Number of Appliances X Discharge Units per Appliance)
- System – Changing the system will update the Discharge Units per Appliance to the default values of that system.
- Appliance – The type of appliance.
What is rate of discharge?
The discharge rate is defined as the steady current in amperes (A) that can be taken from a battery of defined capacity (Ah) over a defined period (h). Batteries for CEGB power stations are normally specified for a 10-hour rate.
Why do we measure discharge?
What are the equipment used to measure river discharge?
ADCP (acoustic Doppler current profiler) is the most advanced instrument for river discharge measurement.
How do you calculate discharge per unit width?
Discharge per unit width considering flow in open channels calculator uses Discharge per unit width = sqrt((Critical depth^3)*[g]) to calculate the Discharge per unit width, The Discharge per unit width considering flow in open channels is known while considering the critical depth to the power of three and gravity.
How do you calculate discharge rate?
What is discharge measurement method?
How is canal discharge calculated?
The principle is the same as of venturi meter, and the discharge of the channel is determined by formula (refer to figure). 𝑄 = 𝑎1 𝑎2 2𝑔(ℎ1 − ℎ2) 𝑎1 2 −𝑎2 2 Where Q =discharge of channel a1 =waterway of the channel a2 =waterway at throat section h1 =depth of water in upstream side h2 =depth of water in venturi flume.
How do you measure streamflow and discharge?
Most streamflow (discharge) measurements use a technique where the cross-section of the stream is “cut” into subsections. Depth, width, and velocity are measured in each section to calculate the volume of streamflow (discharge). The streamflows in all sections are then added up to get the total for the stream.
Streamflow, or discharge, is the volume of water moving down a stream or river per unit of time, commonly expressed in cubic feet per second or gallons per day. Because stream discharge cannot be measured directly, it must be computed from variables that can be measured directly, such as stream depth, stream width, and streamflow velocity.
How does a USGS stream gauge measure streamflow?
Most USGS streamgages transmit stage data by satellite to USGS computers where the stage data are used to estimate streamflow using the developed stage-discharge relation (rating). The stage information is routinely reviewed and checked to ensure that the calculated discharge is accurate.
How is discharge from a river calculated?
In general, river discharge is computed by multiplying the area of water in a channel cross section by the average velocity of the water in that cross section: The USGS uses numerous methods and types of equipment to measure velocity and cross-sectional area, including the following current meter and Acoustic Doppler Current Profiler.