# Geography Rivers

Method

Measuring the Speed of Flow

Equipment used: Ball, Stopwatch, Tape Measure.

Firstly, we measured 3 metres to where we started and finished. We then recorded how long it would take it to travel the 3 metres. One person was standing where the ball had to reach, another was dropping the ball into the water and another was timing it with a stopwatch.

We repeated this test three times to make it more accurate. We also repeated it in three different places; the left bank, the middle and the right bank. We did this to work out which area of the river had the fastest flow.

Measuring Depth

Equipment: Measuring Tape.

For this, we needed to measure how deep the river was, so we used a measuring tape. To make sure this was accurate we measured across from the left bank to the right bank.

Measuring Width

Equipment: Tape Measure.

After measuring the speed of flow and depth, we had to measure the width. We had to measure the full bank position and the width of the river channel to see the difference in each section. The river is neither too big nor too small, so it is easier to measure. We carried out this experiment in three positions and the meander.

Equipment: Tape Measure.

To carry on with this experiment we had to measure ten different stones or pebbles in each section of the river. These stones/pebbles were not where the river was flowing; the stones/pebbles were found when the water was not travelling at a great speed. We measured each stone/pebble by the length, width and diagonally.

The pebbles were different in every part of the river;

They were bigger at the source and got smaller as the river disappeared.

Problems.

There were a few problems with this investigation, which stopped us getting the right equipment, which made the results less accurate. The first problem was finding a place to measure; there was lots of private land and farmland, which stopped us getting to the best places. There were also things in the way that stopped us collecting the data we needed and looking what the river was like before. The reason for using a tennis ball is because the real equipment is too expensive to buy and the tennis ball will give us the same results because it floats on the water.

Discharge is the amount of water passing a specific point at a given time and is measured in cubic metres per second. The discharge depends on the river’s velocity and volume. As the river moves down towards the sea its discharge will increases because of more water from the tributaries. This will lead to an increase in velocity and less friction with bed and banks so more energy in the river, which will lead to more erosion.

When we look at the velocity we can see it increased from 0.15 m/sec at the upper course to 0.51 m/sec ...