Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)
-
Upload
dorothy-cross -
Category
Documents
-
view
27 -
download
2
description
Transcript of Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)
![Page 1: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/1.jpg)
Nourishments and shoreline changes
uninterrupted coast Egmond-Bergen
(The Netherlands)
Ruud Spanhoff (RIKZ) and Stijn de Keijzer (University of Amsterdam)
Kathelijne Wijnberg and Stefan Aarninkhof (WL | delft hydraulics)
Coastview meeting, Bologna, Italy, 4/5 March 2004
![Page 2: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/2.jpg)
![Page 3: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/3.jpg)
![Page 4: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/4.jpg)
![Page 5: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/5.jpg)
![Page 6: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/6.jpg)
Nourishments Bergen-Egmond since 1999
![Page 7: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/7.jpg)
![Page 8: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/8.jpg)
![Page 9: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/9.jpg)
![Page 10: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/10.jpg)
Objective
• Monitor a nourished beach with Argus video remote sensing technology in terms of one or more CSI’s defined in the Coastview project
• Analyse relation between seasonal wave forcing and
beach evolution
![Page 11: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/11.jpg)
Study area
• Egmond (NL), Argus site: Jan van Speijk lighthouse
• Beach nourishment: • June 30 – July 5, 2000 • location: y = 0 – 800 m• volume 0.2x106 m3
![Page 12: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/12.jpg)
Data set
Morphology: 48 monthly intertidal bathymetries (IBMapper)
t range : June 1999 - April 2003
y range: -680 m to +680 m
z range: 0/-0.4 m NAP to + 0.9 m NAP
► +0.2 m NAP contour (Mean Tide Level)
► Beach width (0m to +0.9m contour)
Hydrodyn.: 3-hourly observations of:
► Hrms, Tpeak, angle of incidence (θ0) (YM6, ELD)
► Water level (IJmuiden, Petten)
![Page 13: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/13.jpg)
Methods (1): morphological data analysis
• Temporal evolution of alongshore-averaged MTL position
• Temporal evolution of spatial patterns in MTL position
set of spatial patterns empirically defined by EOF method (empirical eigenfunctions)
• For comparison to seasonal wave forcing: • linear subsampling to 3-hourly interval• Hanning filter, 90 days window width
![Page 14: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/14.jpg)
Methods (2): seasonal wave forcing
• Cross-shore component of nearshore wave energy flux:
evaluated at 6m –NAP depth contour
• Extract seasonal signal:
• Hanning filter
• 90 days window width
218
cos( )sn rms gE gH c
![Page 15: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/15.jpg)
The data (1)M
on
thly
In
tert
idal
Bath
ym
etr
ies
(aft
er:
Caljou
w /
Nip
ius) Egmond station
‘Jan van Speyk’
June 1999-
August 2001
![Page 16: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/16.jpg)
Egmond station‘Jan van Speyk’
October 2001-
April 2003
Mon
thly
In
tert
idal
Bath
ym
etr
ies
The data (2)
![Page 17: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/17.jpg)
The data (3)Mean : 57 m 57 m 0 mSt.dev. : 29 m 16 m 25 mVariance : 838 m2 211 m2 (25%) 627 m2 (75%)
![Page 18: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/18.jpg)
Results EOF analysis
Variance explained by EOF1: 83.1%
= beach nourishment
Example: MTL position (+0.2m contour)
![Page 19: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/19.jpg)
Reconstructed MTL positionbased on EOF1 only
![Page 20: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/20.jpg)
Correlation between seasonal wave forcing and alongshore-averaged contour evolution
![Page 21: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/21.jpg)
Correlation between seasonal wave forcing and amplitude evolution EOF 1
![Page 22: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/22.jpg)
Correlation between seasonal wave forcing and beach width evolution
![Page 23: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/23.jpg)
Conclusions
At Egmond beach :
• Position of the shoreline largely (75%) determined by positioning and amplitude of naturally occurring spatial patterns, rather than cross-shore movement of the beach as a whole
• Beach nourishment incorporated in dominant spatial pattern (explaining 83% of spatial pattern variance) within months
• Seasonality wave forcing of subordinate importance in observed beach evolution
• Regarding prediction of beach evolution at seasonal scale we need to assess the relation between bar evolution and beach evolution (e.g. delayed beach response?).
![Page 24: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/24.jpg)
![Page 25: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/25.jpg)
![Page 26: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/26.jpg)
![Page 27: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/27.jpg)
![Page 28: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/28.jpg)
![Page 29: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/29.jpg)
![Page 30: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/30.jpg)
![Page 31: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/31.jpg)
![Page 32: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/32.jpg)
Longshore position 2942
June 1999
September 1999
March 2000D
istance from R
SP H
eight (m)
![Page 33: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/33.jpg)
9 June 1999
20 December 1999
5 October 1999
15 March 2000
![Page 34: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/34.jpg)
![Page 35: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/35.jpg)
![Page 36: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/36.jpg)
5 September 2001
11 September 2001
77 hours NNW-storm (315-330)
![Page 37: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/37.jpg)
![Page 38: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/38.jpg)
Variance explained by EOF1: 83.1%
= beach nourishment
![Page 39: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/39.jpg)
![Page 40: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/40.jpg)
![Page 41: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/41.jpg)
December 2003
![Page 42: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/42.jpg)
Conclusions
Present case / in general:
• Local problems (1-2 km, 1-5 years) can only be properly understood/tackled by involving larger scales (tens of kilometers/years)
This uninterrupted coast (Egmond-Bergen):
• 3D features important, also on a decadal timescale
Local shallows (spacing 2km) on the breaker bar
Interplay between bars and shore
![Page 43: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/43.jpg)
Conclusions (continued)
After the shoreface nourishment(s):• NW-storms straighten the bar/
SW-storms induce crescentic shapes between the shallows
(local shoreline: S-N oriented)
![Page 44: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/44.jpg)
Conclusions (continued)
• Shoreface/beach nourishment quite satisfactory in terms of CSI’s (4-5 years stead of 2 years)
Negative side-effect probably could have been prevented
Argus (with its high resolution) helpful :• At a local scale, and as a complementary
instrument in studies of larger scales
In the design of a new nourishment ?
![Page 45: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/45.jpg)
![Page 46: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/46.jpg)
![Page 47: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/47.jpg)
10 O
ctob
er 2
000
24 N
ovem
ber
200
0124 hours S
W-storm
![Page 48: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/48.jpg)
SW
-storm (30 hours)
NW
-storm (25
hours)
Dec
embe
r 20
00
1214
16
![Page 49: Nourishments and shoreline changes uninterrupted coast Egmond-Bergen (The Netherlands)](https://reader030.fdocuments.in/reader030/viewer/2022032709/568131be550346895d98265c/html5/thumbnails/49.jpg)
29 December 2001
22 February 2002South 96 hoursNorth 13 hours
24 February 2002North 38 hours
28 February 2002South 25 hoursWest 19 hours