25 Apr

  • By wendydodds

What have a rubber mallet, a tarpaulin, sluice gates and garden spray bottles got in common? The answer is that they were all key elements of the Year 13 geography trip to Leeson House FSC in Langton Matravers on Tuesday.

This was the last of the 4 compulsory day’s fieldwork that students in Year 13 have to undertake in order to meet the A2 specification. The topic of the day was the operation of the water cycle in the Swanbrook River catchment and consisted of a mix of collecting and analysing primary data together with observations and some supplied secondary data. Expert tuition was provided by the centre’s tutor Louise.

Students enjoyed the 3 main practical experiments to determine why the area is prone to flooding. The first involved pouring a measured amount of water onto 3 different surfaces, concrete, gentle slope and steep slope and measuring the speed and quantity that ran off. From this we found that impervious and steeply sloping land lead to rapid run off and enhanced the potential for floods.

The next task was to spray water from a garden sprayer onto the leaves of 3 different trees and see which was the most effective at interception. A tarpaulin was used to catch the water not intercepted and this was channelled into measuring beakers with readings taken every 30 seconds. Surprising to many, the coniferous tree was the most effective interceptor but the deciduous trees had only just come into leaf after the arduous winter, which made an unwelcome reappearance with fog and frequent showers on the day. Note: don’t give Riley a job involving sprayer use.

Finally, we looked at whether soils had a higher infiltration rate in grassland or woodland areas. A rubber mallet was used to knock a tube 5cms into the soil. The tube was filled to 10cms depth with water and the amount of infiltration was measured using a ruler at the inevitable 30 second intervals. Results differed due to variations in site and the vigour with which the mallet was used. Note: do give Matt a job involving knocking pipes into the ground.

To round off the day, we visited Swanage and saw the flood relief culvert, the alterations made to the river by the Victorians, the sluice gates to prevent flooding of the urban areas and the low value land that was allowed to flood. Most people were amazed by how such a small river could potentially cause so much havoc. Brittany was amazed by how wet her feet were!

Thanks to Peter Morton for driving and visiting Macdonalds and Mrs Humphreys for her support too. Everyone had a great day and will hopefully have learned some useful information they can utilise in the upcoming exams.

Steve Wilson