Beach Monitoring Reports
January 2014 Report
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spread sheets of all data
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photos for each monthly measurement.
Date: 1 January 2014
Monitoring Team: Mark, Nick & Ian
Analysis & Report: David Bills-Thompson, PFCG Technical Officer and Data Co-ordinator
Commentary: A significant result this month is the positive gain in sand height at all
reference posts. This is the first time a total gain has been recorded in 50
weeks.
This data is best viewed in a new chart called Height Table 0114.pdf. This is not
new data, just a clearer way of highlighting gain and loss.
Now that we are approaching a full season of data collection, there is
evidence of seasonal variation visible in the height table. The pattern of
colours around posts 5 and 6 suggest that this part of the beach has the
greatest potential for reliable sand gain.
The greatest sand gain was at post 8 and although the height has not yet
reach the level of 12 months ago, it has exceeded the level in April when the
first profile measurements where taken.
This dramatic performance at post 8 is another example of the instability we
can expect at this part of the beach. Sand heights at Post 8 continue to be the
lowest known points on the beach.
The general increase in sand height is also visible in the beach profiles
starting at posts 4 and increasing around through the higher numbered posts
where there is a noticeable gain in sand height in the deeper water, giving the
effect that the tide is going out further.
The Profile Post 8 0114.pdf shows a large amount of sand build up in the deeper
water. See also the other post profiles.
The sand height increase seems to have influenced the dune toe distance
with all except post 5 recording a reduction in dune toe distance. Post 9 has
had the largest toe reduction which also made it difficult to decide where the
toe was.
Another method of toe measurement using laser heights behind the post may
be required on all of the posts and not just 11 and 12 as predicted with earlier
observations.
The real value of beach monitoring will be apparent in another 12 months
when we are able to quantify the net annual loss of sand in various locations.
I am assuming there will be a net annual loss by comparing the data from
1996 with today.
Measurements of the dune crest were also taken at posts 8 and 9 along with
lateral crest positions at NS1 and NS2 (Between posts 5 & 6). This data has
not yet been evaluated.
While walking between posts 8 and 9 behind the dune crest, I noticed a
number of flat leafed sticky weeds that were holding a considerable amount of
sand. Surrounding weeds that were not sticky did not hold any sand. This
sand had obviously been carried there by wind so we should not discount the
amount of wind erosion that is also occurring.
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Absolute toe distance 01114.pdf (7KB)
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Dune toe distance 0114.pdf (14KB)
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Height table 0114.pdf (25KB)
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Post sand height range 0114.pdf (4KB)
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Profile post 4 0114.pdf (7KB)
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Profile post 6 0114.pdf (8KB)
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Profile post 8 0114.pdf (7KB)
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Profile post 10 0114.pdf (7KB)
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Sand height date series 0114.pdf (16KB)
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Sand height post series 0114.pdf (9KB)
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Toe distance range 0114.pdf (4KB)