On Sunday 1st March, in preparation for the fieldwork skills exam, pupils in the Lower Sixth investigated eight sites on the River Glaven. Three teams looked at physical changes to the river channel from Selbrigg Pond near the School and its source area, to Wiveton Bridge near Cley. The Glaven is only seventeen kilometres long and mainly rests on chalk beds. It starts at about fifty metres above sea level and due to the permeable nature of the chalk hills; the level of the river does not vary much throughout the year. There used to be nineteen water mills along its course during the Domesday records, with six remaining today. There are three man-made lakes at the Hempstead mill pond, Edgefield Hall Lake and Bayfield Hall Lake. This gives the river a stepped profile down to the sea. There have been a lot of river restoration projects in recent times to make the Glaven a more ecologically sound valley such as the creation of water meadows with more meandering channels. Some parts of the Glaven have been engineered to create riffles and pools, thus putting more oxygen in some parts and providing more hiding places for fish. Many farmers along the floodplain are using more organic methods and creating habitats for wildlife.
The teams now have to analyse the mass of data (wetted perimeter, discharge, bed load and frictional scores) using Spearman Rank Correlation and Standard Deviation statistical tests. Gresham’s is lucky to have such an interesting and natural river system on our doorstep.