Investigating Rivers: Topic Detectives

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The velocity of a river is the speed the water flows. The velocity will change along the course of a river. Place a metre ruler into the river until it touches the river bed. Record the distance between the river bed and the surface of the water. You should do this at regular intervals between the banks of the river. Add the depths together and divide by the number of recordings you took to calculate the mean depth. River depth is how deep a river is. Depth changes across a river channel due to material on the river bed. Therefore, it is useful to calculate the mean depth. It is not possible to measure river discharge directly in the field. Instead, you need to take measurements that allow you to calculate discharge. In situations where access is more limited you may have to take a more opportunistic approach to sampling – however in this case it is sensible to get as close as possible to a systematic sample as possible.

If you have a flow meter it is very easy to measure the velocity of a river in the field. If you don’t have a flow meter you can take measurements in the field using a float, stopwatch and tape measure. Once you have recorded the appropriate data you can use the formula below to calculate the velocity. The cross profile of a river changes as it moves from the upper to lower course as a result of changes in the river’s energy and the processes that the river carries out. Measuring sediment size and type mathsf{Discharge \;(m In justifying your choice of the variables you have measured it can be helpful to consider the linkages between the different river variables. Measuring river discharge Extend a tape measure from the point where the dry bank meets the water on one side of the river to the same point on the other side (hold it taut about 20cm above water level). Record the length, viewing the reading from directly above the tape measure.Coastal Environments CPD – Erosional Erosion, Coastal Management, Deposition and Fieldwork on the Holderness Coast It is not possible to measure river discharge directly in the field. Instead take measurements which will allow us to calculate discharge.

There is a range of things you can use for a float including an orange. We recommend dog biscuits because they break down in water if swept away! It introduces many key river concepts and a wide range of related vocabulary. First the presentation recaps the main processes of the water cycle. It then introduces some of the well known features of river systems (e.g. waterfalls and lakes). There are two activities: Which river channel characteristics you chose to measure will depend on the question you investigate. To gather your data you need to measure a distance of 5 metres downstream. 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. Next, use the above formula to calculate the velocity.For the collection of your qualitative data it is not necessary (or practical!) to measure all parts of the river – you will need to take a sample. According to the Bradshaw Model, the wetted perimeter of a river should increase along its course. Measuring the cross profile of ariver Measuring the width of the river channel enables you to calculate the cross-sectional area. Also, according to the Bradshaw Model, channel width increases downstream. Measuring the wetter perimeter of a river