lOMoARcPSD|2406970
Summary Coastal Dynamics I: complete
Coastal Dynamics I (Technische Universiteit Delft)
, lOMoARcPSD|2406970
Chapter 3:
Chapter 2:
E=Ek+Ep=pg2
Wide continental shelf: facilitates sediment accumulation and rapid
coastal progradation, reduce wave energy, amplify tidal amplitude, have
higher potential storm surge elev.
Random phase model: in deep water and not too steep waves the phases
Leading edge coast: narrow shelf, steep profile, large waves, short steep
streams, coarse sediment supply from river, at edge of crustal plate are uniformly distributed between - and . Surface elevation is Gauss-
Amero-trailing edge coast: wide shelf, large sediment supply, broad distributed.
coastal p lains, deltas and barriers. Most mature trailing coast
Afro-trailing edge coast: continent in middle of plate, little sediment
supply, slow coastal development.
Sandy coasts: humid climates, passive margin coasts, 20-40 latitude,
energetic wave/tidal environm.
Holocene: sealevel rise, pleistocene: ice age-> sea level fall Dispersion relationship: √ c=L/T=/k
Effects: Eustatic(amount of water, expansion of water, ocean basin Group velocity is smaller than phase velocity except for very long waves
volume, shape of oceanic geoid) and regional(seismic, isostatic(loading by Dissipation processes filter out shorter waves, dispersion is due to
ice/water), land subsidence) different wave speeds.
Re/transgression: sea/landward shift of the shoreline Sea: Variable height/direction, high, short, steep slow
Pro/retrogradation: sediment is deposited such that shoreline moves Swell: Regular, lower, longer flatter, faster
Sea/landward Wavegroups: Dispersive wave groups: waves disappear at the front and
Emergence/Submergence: land emerges out of the water/land is flooded reappear at back, individual waves travel faster than group wave front.
due to relative sealevel fall/rise Grouping: kgroup=k1-k2 (same for )-> cg=k
Classification: Material(hard/soft), Inman&Nordstrom(Tectonic controls),
Valentin(sea-level):advanced vs retreated coasts. Shepard (dominant Generation of tide
processes):primary(shaped by non-marine agencies) vs secondary(shaped
by marine agencies).
Rotation of earth: 23hr56min. Lunar month(sidereal month): 27.3 days(to
same point 29.5 days due to rotation of earth around sun(catch up)), Lunar
day: 24hr50min, Solar year: 365.25 days.
Gravitational attraction of moon and sun provide centripetal acceleration.
The differential pull generates the tide, also called tidal force.
Tidal components: M2: 12hr25min eq ampl: 0.24m S2: 12 hr eq ampl:
0.11m
Period between 2 spring tides M2 and S2:
Tidal constituents: K1, O1: Moon declination. K1, P1: sun declination.
K1,P1,O1: diurnal inequality. K2: Amplitude modulation of M2/S2 for
declinational effect of moon and sun.
Tidal propagation is hindered by continents.
Small amplitude long wave:
Coriolis
Coriolis effect diverts a moving particle to the right(left) on the
Northern(Southern) hemisphere. Newtons
Galloway equations are only valid for a fixed inertial
frame, Coriolis is needed to correct for our
accelerating non-inertial frame. NH: x,y-plane
turns anti-clockwise
Amphidromic points(have zero tidal range) NH=anti-clockwise
Co-tidal/phase lines: lines of simultaneous HW(radiate from node)
Co-range lines: lines of constant tidal range(concentric)
Degenerate point: centre located over land
Shore classification
Kelvin waves: Coastally trapped due to Coriolis force
u=0, f=constant, no friction gives:
Cross shore momentum balance is geostrophic: pressure gradient
balances Coriolis. Alongshore momentum balance: inertia balances
pressure gradient, alongsh. velocity in phase with water lvl, in NH keeps
coast on starboard side(right)