What can we find out about our local river?
For this section, the teacher needs to find a suitable local river for the children to study. A stream is best; the River Len in Fairbourne Lane, the White Drain River in Boughton Under Blean and the River Darent in West Kent are three suitable sites.
ACTIVITY ONE : Site Diagrams.
Before the children can study a local river, they need to be able to draw site diagrams of the river i.e. accurate sketches. This is important particularly if the teacher wants the children to draw sketches of the parts of the river that they have studied. The children need to understand that a site diagram is an accurate sketch of the river and is also labelled. The children need to be able to label the following things on a site diagram; left and right banks, evidence of erosion and deposition, fastest flow of water, and any other significant features such as a large stone/boulder, clumps of grass in the river, a tree branch in the water, a tree growing in the water etc. For the right and left bank the children need to understand that water flows from the source to the mouth and if they face the way that the water is flowing, the right and left banks will correspond to where their right and left arms are. This work wild probably be best done over two lessons.
RESOURCES REQUIRED
ACTIVITY TWO : The relationship between how fast a river flows and sediment type.
For this activity, the teacher will need to have done a pre-visit to a local stream as two different sites are required. The first site should be where the sediment type is pebbles and stones and the second site should be predominantly mud/silt. Below is a photo of what a suitable stream looks like. Lots of parent helpers are required (1 per 4/6 is ideal) and it is a god idea for classes to go individually rather than as a year group so that the sites do not get over crowded. Also the teacher needs to mark the sites using flags or something else before the actual visit so that the parents know which site is which and where to go and the sites need to be close to each other if possible.
The aim is for the children to find out if sediment type has any effect on how fast a stream travels. Generally the stream should travel fastest over the pebbles and stones as there is less friction between the pebbles/stones and the water. But this is not always the case. It is best not to tell the children what they should find as it is complicated to explain to the children why sometimes the stream flows fastest over the mud/silt. It is better to let the children make their own conclusions based upon hat they have found.
The children need to do two experiments to test this hypothesis by firstly doing a survey of the sediment type at each site for the left bank, right bank and midstream. They then need to see how fast the river travels at both sites, again at the left bank, right bank and midstream -Worksheet 30. If the children are unfamiliar with using a stopwatch, then Worksheet 31 will help them with this. It is suggested that younger children just measure the speed at which the river travels at each bank once, whereas older children can do this three times and then work out the average speed. Worksheet 32 is suggested for older children.
RESOURCES REQUIRED
2 poles per group.
6 corks per group.
2 metre sticks per group.
1 stopwatch per group.
Wellington Boots.
Clipboards.
ACTIVITY THREE : Stream Visit : Meanders.
If the stream that the children are visiting has a meander, then this is a good opportunity for the children to observe erosion and deposition on a meander first hand. The children should already have a good understanding of meanders and work at a local stream will only serve to reinforce these concepts.
RESOURCES REQUIRED
1 stopwatch per group.
2 corks per group.
Wellington Books.
Clipboards.
The above items are not extra items if this activity is done alongside Activity Two on the same visit.
ACTIVITY FOUR : What is the relationship between how fast the river travels and depth of the river?
This activity is similar to Activity Two and it should be noted that if the teacher decides to do Activity Four alongside Activity Two using the same sites, then the velocity experiment need not be repeated. However it is suggested that different sites are used for this activity for two reasons; firstly the children will spend too long at one site, potentially causing problems when other groups want to use that site and the previous group has not finished; and secondly it prevents the children from getting their results mixed up and thus ending up confused about what they have learnt from the activities. It is also recommended that the children do Activity Four on a different day than Activity Two, although it is recognised that with time and transport constraints that this may not be possible. Again the teacher should preview the sites first, one shallow site and one deeper site is best. Also the sites should be marked with flags before the visit so that everyone knows where they are going and the sites should be quite close to each other if possible.
The aim is for the children to test the relationship between the stream velocity and the depth of the water. Generally where the river is travelling the fastest, the river is shallow and where the river is deeper, it travels slower. This is because there is a greater volume of water to travel the same distance. Again older children can do Worksheet 35 and find out the average velocity. It is suggested again that younger children just do the velocity part once. The children can do a site diagram for each site if they wish, but it is suggested that this is not necessary.
RESOURCES REQUIRED
2 poles per group.
6 corks per group.
2 metre sticks per group.
1 stopwatch per group.
1 30cm ruler per group.
Wellington Boots.
Clipboards.
ACTIVITY FIVE : River Pollution.
Whether the children can do this activity or not greatly depends upon the local river upon which the teacher has chosen. If there are no visible signs of pollution in the river such as crisp packets, then this activity is unsuitable or another river needs to be chosen. It is suggested that a variety of different types of pollution need to be present at two or three sites along the river (within close proximity) for this activity to be effective. For this activity the children could make a note of what different types of pollution they can see and the frequency of each type of pollution. Also the children could compare 2 different rivers and see how the level of pollution is different for each river. Bar graphs of the types pollution and frequency could be made after the visit. It is suggested that the children record their results in a table, like the one in Worksheet 36. In addition the teacher may wish to do this activity after the section about pollution has been completed.
RESOURCES REQUIRED
A suitable river displaying evidence/signs of pollution.
Wellington Boots.
Clipboards.
ACTIVITY SIX : The Source of a River.
If part of the river that is studied is close to the source of that river, it is a good idea to take the children to visit the source, as this reinforces concepts already learnt previously. It also affords the children the opportunity to see the source first hand. Ask the children to make a sketch of the source and to label any significant features such as water bubbling up from under the ground to the surface. Also it is a good idea to get the children to write a description of the source.
RESOURCES REQUIRED
Wellington Boots.
Clipboards.
Paper.
ACTIVITY SEVEN : Project : The Relationship between how fast a river flows and sediment type.
Firstly discuss the children's results as a class as the children need to understand that higher time values mean a slower river and low time values mean a fast river. Explain that the children are going to do a project about the river that they have studied. Depending on the age and ability of the children (Year 2, 3 and 4 children are able to do Worksheet 37), the teacher will need to decide whether the work should be done individually, in pairs or as a small group. Also the teacher needs to decide whether the children should hand write or word process their work. It is suggested that older and younger children could do the same type of work as Worksheet 37 and 38 offer a good guide to presenting projects. The project needs to be divided into sections:
1) Introduction - what river the children studied, where it was and when they went.
2) Method - Description of the Time and Sediment Experiments.
3) Results - neat copies of the site diagrams and tables. Also a written explanation using Worksheet 37 as a guide.
4) Conclusions - what the children found out using Worksheet 37 as a guide.
5) Front Cover - title, picture, names of the group etc.
This work will take quite a while to complete; therefore it is suggested that if the children do either Activity 2 or 4 as a project, not both.
RESOURCES REQUIRED
Worksheet 37 - younger children.
Worksheet 38 - older children.
ACTIVITY EIGHT : Meander Results.
As a class discuss what the children found out at the meander site. Explain that the children are going to write up their results neatly about the meander. The same activity is suitable for both older and younger children.
RESOURCES REQUIRED
ACTIVITY NINE : Project : The relationship between how fast the river travels and the depth of the river.
If the children have already done the other project, it is suggested that doing this one is not necessary. However it could serve as a useful exercise for those children who finish early and is more suitable for older children. However brighter children of Years 3 and 4 could probably do this project. The project needs to be divided into sections:
1) Introduction - what river the children studied, where it was and when they went.
2) Method - Description of the Time and Depth Experiments.
3) Results - neat copies of the tables, cross-sectional area diagrams, and a written explanation using Worksheet 40 as a guide.
4) Conclusions - what the children found out using Worksheet 40 as a guide.
5) Front Cover - title, picture, group names etc.
RESOURCES REQUIRED
Graph paper.
Worksheet 40 - younger children.
Worksheet 41 - older children.
