Beach Monitoring Reports
December 2014 Report
Date: Sunday 7 December 2014
Monitoring Team: Nick, Mark & Scott
Analysis & Report: David Bills-Thompson, PFCG Technical Officer and Data Co-ordinator
Commentary: In general, they are good results for the beach, although this month has had a lower increase in sand height at the posts than last month, the increase is spread over more posts so more of the beach is benefiting.
Eight posts gained sand, two had no change and only 10mm losses were measured at posts 11 and 12. Despite this minor sand loss, the general sand heights at posts 11 and 12 are above average.
A new characteristic has developed for post profiles 1 - 6 showing simultaneous sand gain and loss between the Foreshore and the Backshore. This is particularly noticeable in the Post 4 Profile.
In an effort to understand the system, two new charts have been drawn. The Post 4 profile has been redrawn using averages of the three readings per season but will need two more readings for the Summer of 2015. This differential sand movement did not occur this time last year.
Another sand height chart has also been drawn for a point 15 metres seaward of the posts. At 15 metres, only post 4 records a sand loss for the last month. If the sand height was taken at 20 metres, all posts would have recorded a sand gain during the past month.
Post 7 shows a slight uniform gain in sand height across the beach.
Posts 8 and 9 show recovery of sand height in the Foreshore area to match previous profiles.
Note the subtle difference in the profiles 1-6 compared to 8 & 9 for November 2014 and December 2014.
For posts 1-6 in November, the beach was almost uniform gradient while the December profile shows a marked step.
The reverse is true for posts 8 & 9. In November they had a distinct dip which has now leveled out in December.
As the sand build up is not expected to peak before Autumn 2015, perhaps the above is just work in progress and we are seeing some of the mechanism of sand movement.
Dune Toe results for post 8 behind the WEDs continue to be stable with only minor movement, however posts 5 & 6 have had a very active dune toe during the last month.