1. Identifying the impact of the winter 2013/14 storms and subsequent remediation work on the sediment at Chesil Beach Dr David Graham Department of Geography Loughborough University

2. Context of Chesil Beach BMU 3 BMU 1& 2 Cove Inn UNESCO SAC SPA SSSI Geomorphology Particle size and composition

3. January / February 2014 storms

8. Why is grain size important? SSSI citation ‘Closed system’ – only ‘18 billion’ pebbles left! Uncertainty remains over causes of size grading Control on flood risk Wave energy/run up Percolation and overtopping

10. Digital Gravelometer Commercial software package developed at Loughborough Photographic sampling + digital image analysis Originally developed for river sediments Used internationally Key benefits: Very rapid  facilitates high-resolution sampling  cost effective Non-destructive

14. 27 profiles 189 samples c. 1000 images Consistent locations

15. 27 'Wolman' samples for control

16. Results: magnitude of errors Image processing procedures not optimised for beach sediments (well sorted) Calibrated using 'Wolman' data Small errors after calibration (c. 5%)

17. Results: along-beach trends

18. Results: across-beach trends

19. Results: summary diagram

20. Key finding: “Limited evidence” of impact Long shore:  No obvious discontinuity at management boundary  Some evidence of difference in ‘shape’ of grain size distribution but magnitude very small Cross shore:  Most variation in managed unit BUT this was small and within most dynamic section of the beach Project generated benchmark dataset for future monitoring

21. The report is available in the Loughborough University Institutional Repository: https://dspace.lboro.ac.uk/2134/18808 The data are available in the Loughborough University Data Repository: l DOI:10.17028/rd.lboro.2002947