Velocity and Sediment Size Data Collection on the Alderbrook River

Make sure you know the correct name of the equipment you have used. Check you understand how it works and how to gather accurate data. Record it neatly in the field. The Hydro-prop measures velocity in seconds, you will have to convert this into a flow velocity in metres / second using the appropriate calculation.


Top left - the image shows the 'Hydro-prop' equipment used to measure the velocity of a river. It is usual to take at least three measurements across the channel at each sampling site on small streams, to get a better picture of the patterns of flow.

Top right - shows the measurement of sediment size. According to the Bradshaw Model, this should decrease as you travel downstream due to erosion via the process of attrition.

Left - this is the Alderbrook River in its lower reaches before the confluence of the River Blythe.

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