ENGR 691, Fall Semester Special Topic on Sedimentation Engineering Section 73 Coastal Sedimentation Yan Ding, Ph.D. Research Assistant Professor, National Center for Computational Hydroscience and Engineering (NCCHE), The University of Mississippi, Old Chemistry 335, University, MS Phone:

Objective The lectures are to introduce morphodynamic processes driven by waves and currents in coasts, estuaries, and lakes. Emphasis is placed on understanding the features of sediment transport and morphological changes induced by combined waves and currents. Numerical modeling in morphodynamic process simulations will be briefly introduced.

Outline Introduction of morphodynamic processes driven by waves and currents in coasts, estuaries, and lakes Initiation of motion for combined waves and currents Bed forms in waves and in combined waves and currents Bed roughness in combined waves and currents Sediment transport in waves Sediment transport in combined waves and currents Transport of cohesive materials in coasts and estuaries Mathematical models of morphodynamic processes driven by waves and currents Introduction of a process-integrated modeling system (CCHE2D-Coast) in application to coastal sedimentation problems

Course Mechanics Grades – Grades will be based on the homework assignments and the lecture Lecture notes: g/Engr691_73_Fall_2010/ g/Engr691_73_Fall_2010/

References van Rijn, L.C., (1993). Principles of sediment transport in rivers, estuaries and coastal seas, Aqua Publications, ISBN: PART I: EDITION 1993; 715 pages PART II: SUPPLEMENT/UPDATE 2006; 500 pages Dean, R. G., and Dalrymple, R. A. (2002). Coastal Processes with Engineering Applications, Cambridge Press. Sorensen, R. M. (1993), Basic Wave Mechanics for Coastal and Ocean Engineering, Wiley-Interscience (ISBN ). Coastal Engineering Manual (2002). Coastal Engineering Manual, Part II: Coastal Hydrodynamics, US Army Corps of Engineers, ERDC, Report Number: EM ( manuals/em /PartII/PartII.htm ). manuals/em /PartII/PartII.htm Mei, C.C. (1989). The Applied Dynamics of Ocean Surface Waves, World Scientific, Singapore. Dean, R.G. and Dalrymple, R.A. (1992). Water Wave Mechanics for Engineering and Scientists, World Scientific, Singapore.

Beautiful Coasts Sunrise at Turtle Bay Resort Hotel, Honolulu, Hawaii, 04/14/2008 Turtle Bay Resort Hotel, Honolulu, Hawaii, 04/15/2008 Waves in Turtle Bay, Honolulu, Hawaii, 04/15/2008

Estuaries and Coastal Waters Mouth of Columbia River, WA Coastal Inlet Ocean City Beach looking north, Maryland Barrier Island Breaching A small estuary

Wave crashed against a boat that washed into Highway 90 in Gulfport, MS, AP Photo Vulnerable Coasts Storm Surge, Hurricane Katrina Water spilled over a collapsed levee in New Orleans on Tuesday (8/30/2005)

Erosion in the beach A beautiful beach before 13 years Embankment and groin for shore protection

Hurricane Isabel Hatteras Island Breach, 21 Sep 03 (Breached ~ 18 Sep 03 )

Vulnerable Coasts Structure Failure by Katrina US 90, Bilox, MS, Feb 26, 2006

NWLON Station AnalysesNew Global Station Analyses Long-term Variations in Sea Level and Analysis of Trends: Exceedance Probability Analyses and the 100-year Event :* * In development 2008 Annual Exceedance Probability Curves1%, 10%, 50%, 99% Exceedance Probability Levels Analysis of Climate Change 12

USGS Published Landloss Since 1932 and Projected For the Next 45 Years NWRC Landscape Change: Predicted Landloss in Louisiana

Spatial and Temporal Multi-Scales of Hydrodynamics and Morphology in Coasts and Estuaries Small-Scale Processes (0.1mm-10m; 0.1s-1day) Fluid and sediment motions in turbulent wave-current bottom boundary layer Intermediate-Scale Processes (1-10km; 1s-1yr) Wave breaking across surf zone, wave-induced nearshore current, lower frequency infragravity wave motions by storm surges, sediment transport alongshore and crossshore, fresh water and sediment from rivers during floods, and tidal motions Large-Scale Processes (1-100km; months-decades) Ocean circulations, sea-level rising, global scale weather change, long-term shoreline change, etc. A challenging goal: a realistic coupled waves-currents-morphologic-ecological evolution model See

Coupling of the small-, intermediate-, and large-scale process: turbulent boundary layer wave deformation Nearshore circulation Sediment movement Shoreline change Bar and tough

Physical Processes in an Estuary

Wave Transformation Columbia River Entrance, WA/OR Breaking Refraction Reflection Shoaling after Smith & Cialone (2000) Wave breaking in a tidal front of an inlet Wave breaking in Turtle Bay, HI, 4/14/08 Wave breaking in a tidal front of the Fraser Estuary, BC, Canada (after Baschek) Strait of Georgia River flow

Wave Transformation Columbia River Entrance, WA/OR, 1966 Breaking Refraction Reflection Shoaling Smith & Cialone (2000)

Seminar for Course ENGR Deformation of Irregular Wave (1) Deformation of wave Refraction Diffraction Reflection Wave Breaking Bottom Friction …… Incident Wave Nearshore wave processes

Seminar for Course ENGR Nearshore Current System (Schematically) Incident Wave Longshore Rip Current Currents generated by breaking wave One Cell Mass Transport

Wave Parameters Figure. Definition of wave parameters Parameter (SI Unit)Conventional NotationNotes Wave Height (m)H Wave Period (s)T Wave Length (m)L Wave Celerity /Speed (m/s)CC = L/T = σ/k Wave number (1/m)kk=2π/L Wave Angular Frequency (1/s)σ (ω)σ = 2π/T, Wave SteepnessH/L Relative Water Depthd/L trough crest

Wave Celerity (1) Solution of nonlinear equation (Newton’s method) A good estimate of initial value of L (deep wave length) Newton’s method n = 1,2, …… Dispersion relation:

Wave Breaking in beach Deep wave breaking

Small Wave Characteristics Shallow (d/L <=0.05) IntermediateDeep (d/L >=0.5) Celerity Wave Length Wave Number2π/L Wave PeriodTTT

Small Wave Characteristics (3) Shallow (d/L <=0.05) IntermediateDeep (d/L >=0.5) Velocity Potential φ Surface Profile η Particle velocity u Particle Velocity w Pressure P Group Velocity CgCnCnCC/2 where

Near-bed Orbital Velocities Applying linear wave theory, the peak value of the orbital excursion (A δ ) and velocity (U δ ) at the edge of the wave boundary layer can be expressed as

Longshore Sediment Transport in Coasts Observations on natural beaches as well as in laboratory wave basins have confirmed that the longshore current is largely confined to the surf zone. This longshore current drives the shoreward movement of longshore sediment transport. Ocean City Beach looking north, Maryland Downloaded from: Wave Current & Sediment Breaking Line

Longshore and Cross-shore Sediment Transport in Local Scale (2D Morphological Change in River Mouth) The total longshore sediment transport model is not useful for this case. Sediment alongshore q l =? Sediment cross-shore q c =? Deposition of littoral sand Movement of littoral sand Erosion Protection (Artificial Headland) River Mouth

Jetty and Navigation Channel Portage Lake Harbor, Onekama, Michigan From Digital Virtual Library, U.S. Army Corps of Engineers

Detached Breakwater Physical model testing of detached breakwaters and beach morphology in CHL's Longshore Sediment Transport Facility (LSTF)

Scour holes at Indian River Inlet, Delaware Aerial Photo Scour: view looking seaward

Hydrodynamic and Morphodynamic Processes in River Mouths and Estuaries Touchien River Estuary Tidal Inlet Flood Shoal River Waves Tides Longshore Current Yangtze River Estuary An estuary: a semi-enclosed coastal water body with a river inflow