Estimate the flow velocity of a river with satellite images

Asked by: Kemar Jones

How do you measure the flow velocity of a river?

Multiply the average depth of the stream by the width of the stream to find the area in ft2. Divide the distance traveled by the average travel time to find the velocity of the stream in ft/sec.

How do you calculate the velocity and discharge of a river?

The discharge of a stream is the product of its velocity (V – length of travel per unit of time such as feet/second) times depth of the water (D – unit of length) times width (W of the water – units of length). (Make sure all all three lengths are expressed in the same unit.)

What is a velocity of a river?

The velocity of a river is the speed at which water flows along it.

How do you calculate surface velocity?

Use the Stream Flow Field Sheet to calculate surface velocity. Divide distance (20 feet) by average velocity time to get average surface velocity in feet per second. Next, multiply this result by the velocity correction factor of 0.8 to get average corrected velocity.

How do you calculate water flow rate?

Measure the number of liters or gallons in the container, and divide that number by 15. This gives the flow rate in liters per second or gallons per second. The formula is F = V/T, where F is the flow rate, V is the volume and T is the time.

What is the formula for calculating flow rate?

The flow rate is given by Q=A¯v or ¯v=Qπr2 for a cylindrical vessel. ¯v=(5.0L/min)(10−3m3/L)(1min/60s)π(0.010m)2=0.27m/s.

How do you calculate velocity from discharge?

Referring to the formula Q = V ´ A, it should be clear that for the same discharge and a smaller average flow velocity, the area of the wetted cross-section has to increase. Thus, due to a lower flow velocity, the water depth will increase and the canal will risk overtopping. 3.3.

How do you calculate discharge velocity?

Discharge, or the volume of water flowing in a stream over a set interval of time, can be determined with the equation: Q = AV, where Q is discharge (volume/unit time-e.g. m³/second, also called cumecs), A is the cross-sectional area of the stream (e.g. m²), and V is the average velocity (e.g. m/s).

How do you find average velocity of a stream?

The average velocity at any location in a stream can be estimated by measuring the velocity at six-tenths of the depth of the stream at that location. This is called the six-tenths rule.

How do you find the velocity of a river in geography?

Quote from video: So let's place it in the middle of the river. Off we go. Past first pole past second poll. Four minute four second 4.15 seconds there's the velocity of the river.

Where is velocity highest in a river?

1. Toward the middle of a river, water tends to flow fastest; toward the margins of the river it tends to flow slowest. 2. In a meandering river, water will tend to flow fastest along the outside bend of a meander, and slowest on the inside bend.

What determines the flow of a river?

The direction of flow is determined mostly by the area’s topography located between the headwater (origin) and mouth (destination). Also, rivers not only follow one direction; some turn and twist in several directions. It is important to note that a compass direction does not influence the flow of a river.

How do you calculate velocity from diameter and flow?

To calculate blood flow rate through a blood vessel:

1. Divide the diameter of the vessel by 2 to obtain the radius.
2. Find the circular cross-sectional area using A = π × r² .
3. Determine the (average) velocity of blood in the vessel.
4. Multiply the area by the velocity to obtain the volumetric blood flow rate.

How is water velocity calculated in open channel?

Using the equation, V = Q/A as a definition for average flow velocity, the Manning Equation becomes: V = (1.49/n)(R2/3)(S1/2), with average flow velocity in ft/sec. In S.I. units this equation becomes: V = (1.0/n)(R2/3)(S1/2), with average velocity in m/s.

How do you calculate water flow in Litres per minute?

Flow rate (L/min) = [Bucket Size (L)] ÷ [Fill time (sec)] × 60 × 0.8

1. 60 is to convert the unit to minutes.
2. 0.8 refers to a 20% reduction in flow rate to allow for pressure loss in your system. If the bucket test is taken off the main water feed at the correct pressure then this 20% allowance is not necessary.

How do you measure river velocity GCSE geography?

To measure velocity we use a flow meter. Using the flow meter measure the speed of the river flow at 5 equally spaced points across the channel. ​At each point measure the speed at the surface, half way between the surface and the bed and at the river bed. Record the measurements on the recording sheet.

How do you measure the velocity of an Igcse river?

Velocity = Distance / Time



One person with a ranging pole should stand at the top and another person with a ranging pole should stand at the 5m mark. Place your float in the water upstream at 0m. Record the time it takes for the float to travel 5m. Repeat this three times and calculate the mean.

How do you measure velocity using a flow meter?

press and hold both left and right buttons simultaneously for 2 seconds to zero the display, and start measurement. for point measurements, hold in the flow until the average velocity is constant, then remove the probe.

Which instrument measure the flow of water?

A water flow meter is an instrument capable of measuring the amount of water passing through a pipe.

What are the various devices used to measure velocity of flow?

Explanation: Venturimeter: It is a device to measure the rate of flow of fluid flowing through a pipe.



Important Points.

Which methods can be used to measure flow rate?

Primary devices are generally considered the most accurate way to measure flow in open channels. An area-velocity meter is an open channel flow meter that measures flow by making two separate measurements of depth and velocity. The depth is converted to cross sectional area using the geometry of the pipe or channel.