Supervised by Kate Smith, at CGES, Bethany Rossiter (BSc Geography at the University of Exeter) investigated the correlation between the increase in tree cover area in the Cober valley, and a decrease in the size of peak flow levels in the river Cober over time.
This aim was investigated through looking at the growth of the Cober valley woodland by analysing satellite imagery and historical maps. Furthermore, changes in peak flow levels were investigated by using Peak Over Threshold data, for two gauge stations on the river Cober, in its upper and lower middle course (Trenear and County Bridge).
Precipitation change was also investigated as a possible cause for any changes in peak flow. Results showed that tree cover increased over time, although peak flow did not increase or decrease. However, a small decrease in peak flow was observed in the upper course. Precipitation influenced peak flow at both stations, although more so in the lower middle course.
This paper concludes that overall, tree cover increase is not significantly correlated with peak flow levels in the river Cober, although a weak correlation was observed in the upper course, suggesting afforestation is more effective at reducing peak flow levels in the upper course.
You can read the Bethany Rossiter’s BSc Dissertation here: 2017 – Investigating the impact of afforestation on the magnitude of peak flow levels in the River Cober, Helston