lOMoARcPSD|2406970
Samenvatting - H 1 - 10
Coastal Dynamics I (Technische Universiteit Delft)
, lOMoARcPSD|2406970
Coastal Dynamics I
Chapter1:
Soft measures: beach nourishments; land reclamation; maintenance dredging
Hard measures: seawall/revetment (permeable), Groyne, Jetty, Breakwater
Tidal inlet: Tide prevents inlet from closing
Obliquely approaching waves: non-zero angle between wave crests and depth contours
Shelf break; overgang naar echt diep water (100-200m depth)
Shoreface: part of sandy profile affected by waves
Shoalzone: waves gain amplitude until they break
Breaker/surfzone: waves break
Coastal morphodynamics (positive/negative): mutual adjustment of morphology and hydrodynamic
processes involving sediment transport
Regression (of sea): advance of coast
Transgression (of sea): retreat of coast
Chapter 2:
Surge level higher for wide shelves; wave energy lower (lot of damping due to bottom friction);
higher tidal amplitude
African coast: Less sediments provide due to absence of real mountains due to fact that Africa is in
middle of crustal
Eustatic change: absolute sea level change (movement of mean sea level w.r.t. land)
Isostatic deformation: deformation of earths crust due to Eustatic sea-level changes
Glacio-isostasy: due to ice
Hydro- isostasy:
Continental sediments: originating from rock
Carbonate sediments: formed of calcium carbonate from shells/remains of marine life
Mud: fluid-sediment mixture of (salt), water, silt, clay and organic materials (created via chemical
weathering.)
Ratio mud/sand: increases for more chemical weathering which is for higher temperatures and
humidity
Reef: needs enough sunlight and warm water
Fringing reef: reef bordering the coast
Barrier reef: reef positioned offshore closing of a lagoon
Atoll reef: reef encircling a lagoon
Salt Marshes: found at moderate climates
Mangroves: found in (sub)tropical regions
Formation of Delta: depends on the relative influence of river(&provided sediment), waves and tide
Ria: drowned river
Elongated sand bars: typical for tide dominated system
, lOMoARcPSD|2406970
Chapter3:
Wave steepness: ratio of H/L
Period wind generated gravity waves: 0.25s – 30s (Gravity is restoring force)
‘sea’: relatively short (order 10s) random & irregular oscillations of surface generated by local wave
fields
‘swell’: sea that travelled for a while and has transformed due to frequency dispersion and damping
Capillary waves: small ripples (0.25s) that die out due to surface tension
Infra gravity waves: longer gravity waves (5min); merely shallow water phenomenon
Wave record stationary: short enough to be statistically stationary, long enough to get reliable
averages (15-30min used, 20min most common)
Short term statistics wave record: 1. Via wave-by-wave analysis. 2. Spectral analysis
Root-mean-square wave height: wave energy measure (since wave energy is related to H2)
Smallest frequency (longest wave) that can be determined: fmin=1/Tr (restricted by record length)
Highest frequency: fmax=1/2deltat (from sampling interval)
Standard deviation can be estimated via area under variance density spectrum
Phase: in not too steep waves and deep water independent of each other and uniform distributed
Spectral peak: indicates point in the spectrum where most energy occurs
Waves at area of generation: relatively steep and short-crested
White-capping: steepness induced wave breaking (H/L>0.14)
JONSWAP: characteristic for developing wind sea in oceanic waters
Pierson-Moskowitz: fully developed sea
Phase velocity(=propagation velocity=wave celerity): rate at which any phase of the wave (for
instance a crest) propagates in space
Shallow water for: kh<0.31 or h/L<1/20
Group speed: is speed at which energy of waves move
Phase velocity > group speed in deep water; same for shallow
Groupiness: caused by interference of waves with different wave length
Dissipation processe(white capping¤ts): more effects on shorter waves
Period of decades conditions may not be stationary (due to for instance climate change)
Gravitational acceleration: varies due to varying distances and angles to the centre of the attracting
mass
Centripetal acceleration: everywhere parallel to line connecting gravitational centers
Differential pull/tide generating force: difference between gravitational pull on ocean water masses
that are located at different distances from the sun and the moon
Normal components: small w.r.t. earth’s own gravitational attraction
Tangentianal/horizontal: same order as normal components but perpendicular to earth’s
gravity field and therefore cannot be neglected
Horizontal component: shifts water to side of earth facing sun(moon) and opposite side in tidal
bulges (pilling up of water = balanced by pressure gradients)
Solar tide: 12 hours (1/2 of solar day)
Lunar tide: 12h25min (1/2 of lunar day)
Sidereal day: time needed for earth to rotate around own axis (=23h56min)
Sidereal month: 27.3 days (moon’s revolution around earth)
Lunar month: 29.5 days
Spring tide: sun, earth and moon in one line
Samenvatting - H 1 - 10
Coastal Dynamics I (Technische Universiteit Delft)
, lOMoARcPSD|2406970
Coastal Dynamics I
Chapter1:
Soft measures: beach nourishments; land reclamation; maintenance dredging
Hard measures: seawall/revetment (permeable), Groyne, Jetty, Breakwater
Tidal inlet: Tide prevents inlet from closing
Obliquely approaching waves: non-zero angle between wave crests and depth contours
Shelf break; overgang naar echt diep water (100-200m depth)
Shoreface: part of sandy profile affected by waves
Shoalzone: waves gain amplitude until they break
Breaker/surfzone: waves break
Coastal morphodynamics (positive/negative): mutual adjustment of morphology and hydrodynamic
processes involving sediment transport
Regression (of sea): advance of coast
Transgression (of sea): retreat of coast
Chapter 2:
Surge level higher for wide shelves; wave energy lower (lot of damping due to bottom friction);
higher tidal amplitude
African coast: Less sediments provide due to absence of real mountains due to fact that Africa is in
middle of crustal
Eustatic change: absolute sea level change (movement of mean sea level w.r.t. land)
Isostatic deformation: deformation of earths crust due to Eustatic sea-level changes
Glacio-isostasy: due to ice
Hydro- isostasy:
Continental sediments: originating from rock
Carbonate sediments: formed of calcium carbonate from shells/remains of marine life
Mud: fluid-sediment mixture of (salt), water, silt, clay and organic materials (created via chemical
weathering.)
Ratio mud/sand: increases for more chemical weathering which is for higher temperatures and
humidity
Reef: needs enough sunlight and warm water
Fringing reef: reef bordering the coast
Barrier reef: reef positioned offshore closing of a lagoon
Atoll reef: reef encircling a lagoon
Salt Marshes: found at moderate climates
Mangroves: found in (sub)tropical regions
Formation of Delta: depends on the relative influence of river(&provided sediment), waves and tide
Ria: drowned river
Elongated sand bars: typical for tide dominated system
, lOMoARcPSD|2406970
Chapter3:
Wave steepness: ratio of H/L
Period wind generated gravity waves: 0.25s – 30s (Gravity is restoring force)
‘sea’: relatively short (order 10s) random & irregular oscillations of surface generated by local wave
fields
‘swell’: sea that travelled for a while and has transformed due to frequency dispersion and damping
Capillary waves: small ripples (0.25s) that die out due to surface tension
Infra gravity waves: longer gravity waves (5min); merely shallow water phenomenon
Wave record stationary: short enough to be statistically stationary, long enough to get reliable
averages (15-30min used, 20min most common)
Short term statistics wave record: 1. Via wave-by-wave analysis. 2. Spectral analysis
Root-mean-square wave height: wave energy measure (since wave energy is related to H2)
Smallest frequency (longest wave) that can be determined: fmin=1/Tr (restricted by record length)
Highest frequency: fmax=1/2deltat (from sampling interval)
Standard deviation can be estimated via area under variance density spectrum
Phase: in not too steep waves and deep water independent of each other and uniform distributed
Spectral peak: indicates point in the spectrum where most energy occurs
Waves at area of generation: relatively steep and short-crested
White-capping: steepness induced wave breaking (H/L>0.14)
JONSWAP: characteristic for developing wind sea in oceanic waters
Pierson-Moskowitz: fully developed sea
Phase velocity(=propagation velocity=wave celerity): rate at which any phase of the wave (for
instance a crest) propagates in space
Shallow water for: kh<0.31 or h/L<1/20
Group speed: is speed at which energy of waves move
Phase velocity > group speed in deep water; same for shallow
Groupiness: caused by interference of waves with different wave length
Dissipation processe(white capping¤ts): more effects on shorter waves
Period of decades conditions may not be stationary (due to for instance climate change)
Gravitational acceleration: varies due to varying distances and angles to the centre of the attracting
mass
Centripetal acceleration: everywhere parallel to line connecting gravitational centers
Differential pull/tide generating force: difference between gravitational pull on ocean water masses
that are located at different distances from the sun and the moon
Normal components: small w.r.t. earth’s own gravitational attraction
Tangentianal/horizontal: same order as normal components but perpendicular to earth’s
gravity field and therefore cannot be neglected
Horizontal component: shifts water to side of earth facing sun(moon) and opposite side in tidal
bulges (pilling up of water = balanced by pressure gradients)
Solar tide: 12 hours (1/2 of solar day)
Lunar tide: 12h25min (1/2 of lunar day)
Sidereal day: time needed for earth to rotate around own axis (=23h56min)
Sidereal month: 27.3 days (moon’s revolution around earth)
Lunar month: 29.5 days
Spring tide: sun, earth and moon in one line
