East Yorkshire coastal erosion

beach levels and cliff loss





This page is intended as an appendix to the sediment segmentation model and the migration chart.

Twice-yearly monitoring of cliff loss under the present system began in 2003, and information on beach contour levels is available from 2008. Although the following table spans eleven years, there is a break where a survey was missed because of poor weather. In effect, averages are calculated using data from ten years.

A coastal length of 52.77km is covered, this being undefended cliff from Bridlington south to the neck of the Spurn peninsula (monitoring profiles 8 to 122/123).

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     A


2008 Aut
2009 Spr
2009 Aut
2010 Spr
2010 Aut
2011 Apr
2011 Sep
2012 Mar
2012 Sep
2013 Apr
2013 Oct
2014 May
2014 Nov
2015 Apr
2015 Sep
2016 Mar
no survey
2017 May
2017 Nov
2018 May
2018 Oct
2019 Mar

averages:
autumn
spring
all

     A

B


41
31
14
43
38
46
  9
25
38
57
20
54
19
33
17
42


26
59
16
23


24
41
33

B

   C
   %
 high
52.60
45.23
53.67
57.26
53.43
58.21
58.05
49.45
52.49
59.50
45.86
54.64
52.24
47.03
63.90
57.68

55.19
53.39
59.55
54.22
61.55


53.99
55.03
54.53

   C

   D
   %
   int.
26.19
38.29
28.12
29.89
30.82
31.19
29.96
29.26
26.17
28.49
35.84
35.53
41.03
42.94
27.92
31.04

32.82
39.86
37.61
42.04
35.55


32.80
33.87
33.36

   D

   E
   %
  low
21.21
16.48
18.21
12.85
15.75
10.60
11.99
21.29
21.34
12.01
18.30
  9.83
  6.73
10.03
  8.18
11.28

11.99
  6.75
  2.84
  3.74
  2.90


13.22
11.10
12.11

   E

   F
   %
 high
42.06
25.90
28.79
41.29
39.17
42.13
31.05
33.22
32.61
47.55
38.71
45.37
37.52
22.42
41.39
37.80


30.76
53.70
42.47
48.03


36.45
39.74
38.10

   F

   G
   %
  int.
20.49
35.59
29.01
33.70
33.60
36.21
22.51
36.81
27.13
32.13
37.27
39.95
52.36
55.93
34.00
40.67


51.54
42.85
50.31
46.31


35.82
40.02
37.92

   G

   H
   %
  low
37.45
38.51
42.20
25.01
27.23
21.66
46.44
29.97
40.26
20.32
24.02
14.68
10.12
21.65
24.61
21.53


17.70
  3.45
  7.22
  5.66


27.73
20.24
23.98

   H

   I
   m
 high
14.38
19.27
  5.10
41.41
29.68
30.28
  6.25
  8.73
24.04
60.16
11.78
59.53
12.39
16.60
10.06
32.29


16.59
74.45
  5.95
18.05


13.62
36.08
24.85

   I

   J
   m
  int.
10.76
34.59
  6.49
51.90
26.07
47.90
  7.66
16.09
28.40
58.52
11.98
59.27
18.79
39.65
13.62
52.55


32.94
71.13
15.35
27.45


17.21
45.91
31.56

   J

   K
   m
  low
28.86
56.14
  9.41
45.69
22.25
33.82
14.09
17.18
30.56
32.32
16.24
21.20
  4.82
17.75
  9.32
25.16


19.47
  4.42
  4.70
  4.50


15.97
25.82
20.90

   K

   L


  54
110
  21
139
  78
112
  28
  42
  83
151
  40
140
  36
  74
  33
110
  55
109
  69
150
  26
  50


  48
108
  78

   L


A: monitoring season.

B: number of monitoring profiles at which cliff loss reported.

C, D, E: percentage of coastal length occupied by high / intermediate / low beach.

F, G, H: percentage of profile sections opposite high / intermediate / low beach.

I, J, K: total cliff loss (landward recession in metres) at profiles opposite high / intermediate / low beach.

L: activity index (detail).

Averages for columns B and L are rounded.
Columns F to K relate to profiles counted in B.

high beach: beach level contour having a minimum of +2.5 metres OD extending for a few metres from the base of the cliff.

intermediate beach: beach level contour between +1.5 and +2.5 metres OD extending for a few metres from the base of the cliff.

low beach: beach level contour having a maximum of +1.5 metres OD extending for a few metres from the base of the cliff.

profile: the intersect of the cliff line by the monitoring line.

profile section: the lateral extension either side of a monitoring line, usually 500 metres in total. See data in detail (profiles).

The charts below are produced from the table.

 
beach contour levels autumn 2008 to spring 2019


cliff loss opposite beach level autumn 2008 to spring 2019

It may be seen that, on average, a little over half the coastal length displays a high, or full, upper beach. Such a beach offers some protection against wave energy. In quieter weather, the high water mark often does not reach the foot of the cliff. The migration chart indicates distribution.

About two-thirds of cliff loss, whether expressed in terms of extent or amount, occurs where the beach is less than full. Around one quarter of loss is opposite a low beach.

The loss of cliff where beach is high would for possibly a greater part be a result of erosion lag. See direct and delayed erosion.




An example of beach level contours data, for April 2015, can be found at the East Riding of Yorkshire Coastal Explorer Interface (Layer List at toolbar right, then tick Beach Level Contours).

Locations of monitoring profiles may be viewed in satellite imagery as follows:

Place descriptions are supplied at data summary and coordinates (spreadsheet).

cliff loss data (menu)

cliff lines




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Prepared by Brian Williams in August 2020.