Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

DSD-INT 2019 SPIT - application of a novel sediment pathway visualization method - Elias

35 views

Published on

Presentation by Edwin Elias, Deltares USA, at the Delft3D and XBeach User Day: Coastal morphodynamics, during Delft Software Days - Edition 2019. Wednesday, 13 November 2019, Delft.

Published in: Software
  • Be the first to comment

  • Be the first to like this

DSD-INT 2019 SPIT - application of a novel sediment pathway visualization method - Elias

  1. 1. 'SPIT: APPLICATION OF A NOVEL SEDIMENT PATHWAY VISUALIZATION METHOD’ A CASE-STUDY FOR THE NORTH-HEAD DISPOSAL SITE, COLUMBIA RIVER, USA Edwin Elias, Stuart Pearson, Andrew Stevens & Maarten van Ormondt D e l f t 3 D U s e r D a y s 2 0 1 9
  2. 2. Delft3DUserDays2019 2 WHY? 1) Visualizations are a great way to explain complex flow and sediment transport patterns 2) Visualizations are a great way to understand complex flow and sediment transport patterns 3) Visualizations are a great way to engage stakeholders Let’s develop a method to do this for sediment transport and sediment transport pathways.
  3. 3. Delft3DUserDays2019 3 It is SPIT, because it is not a Sediment Tracer! Sediment Pathways Interactive visualisation Tool
  4. 4. Delft3DUserDays2019 4 Columbia River (USA) PacificOcean Oregon Washington
  5. 5. Delft3DUserDays2019 5 Columbia River (USA) PacificOcean Oregon Washington
  6. 6. Delft3DUserDays2019 6 PacificOcean Objectives 1) Large dredge efforts in the Mouth of the Columbia River to maintain the Federal Navigation Channel (4,5-6 million m3) 2) Strong erosion observed at Benson Beach. 3) There is a need to keep sediment in the Littoral Cell. 4) Strategic placement in shallow water disposal sites.
  7. 7. Delft3DUserDays2019 7 North Head nearshore circulation and transport pathways modeling Objectives 1) Quantify the sediment linkages between the MCR, North Head shallow water disposal site, and the adjacent open coast beaches 2) Provide guidance on strategic placement of dredged material within the North Head permit area Not a trivial task using standard methods. Can we use SPIT analysis?
  8. 8. Delft3DUserDays2019 8 North Head nearshore circulation and transport pathways modeling Objectives 1) Quantify the sediment linkages between the MCR, North Head shallow water disposal site, and the adjacent open coast beaches 2) Provide guidance on strategic placement of dredged material within the North Head permit area Method 1. Extensive Field-data collection 2. Process-based modelling
  9. 9. 9 Delft3DUserDays2019 Validated MCR model used as base to run Update grid, bathymetry and boundary conditions to examine circulation and sediment transport at North Head Higher resolution grid between North-Head and the MCR; 15 – 100 m in longshore direction, 50 m cross-shore Model Method
  10. 10. 10 Delft3DUserDays2019 Validated MCR model used as base to run Update grid, bathymetry and boundary conditions to examine circulation and sediment transport at North Head
  11. 11. 11 Delft3DUserDays2019 Validated MCR model used as base to run Update grid, bathymetry and boundary conditions to examine circulation and sediment transport at North Head
  12. 12. 12 Delft3DUserDays2019 Morphostatic simulation; 2-day morphodynamic tide case Hsig [m] Tpeak Dir (deg) % 1 1 10,2 279 0,05 2 2,28 8,6 216 0,02 3 2,29 10 241 0,02 4 2,16 11,4 262 0,04 5 2,16 13 278 0,10 6 2,06 11,4 294 0,10 7 3,88 10,1 224 0,03 8 3,87 12,2 257 0,03 9 3,79 13,9 278 0,04 10 3,71 13,4 291 0,02 11 5,76 12,9 241 0,01 12 5,9 15,1 281 0,01 13 0,7 9,8 271 0,03 case Hsig [m] Tpeak Dir (deg) % 1 1 10,2 279 0,05 2 2,28 8,6 216 0,02 3 2,29 10 241 0,02 4 2,16 11,4 262 0,04 5 2,16 13 278 0,10 6 2,06 11,4 294 0,10 7 3,88 10,1 224 0,03 8 3,87 12,2 257 0,03 9 3,79 13,9 278 0,04 10 3,71 13,4 291 0,02 11 5,76 12,9 241 0,01 12 5,9 15,1 281 0,01 13 0,7 9,8 271 0,03 14 1,67 8,4 221 0,03 15 1,58 9,9 259 0,06 16 1,64 10,4 281 0,14 17 1,53 8,6 300 0,17 18 3,5 10,7 241 0,04 19 3,38 13,2 284 0,05 2-day morphologic tide Schematized wave-climate
  13. 13. 13 Delft3DUserDays2019 Morphostatic simulation; 2-day morphodynamic tide Store the: hydrodynamics Sediment transport vector fields and wave heights • Morphostatic simulations – no bed updating. • Store the results as a timeseries every 10 minutes. • These plots show the mean transports averaged over 2 tides.
  14. 14. 14 Delft3DUserDays2019 Morphostatic simulation; 2-day morphodynamic tide Store the: hydrodynamics Sediment transport vector fields and wave heights Post-Processing: Scaled with probability of occurrence to derive mean transports Input for Sediment Transport analysis & Sediment Pathways and Visualization
  15. 15. Mean potential transport during the North Head pilot (September 20 – December 1, 2018) • Southern portion of permit area more active • Note different scaling between left and right maps Model Results Delft3DUserDays2019 15
  16. 16. Model Results; transect-averaged results Delft3DUserDays2019 16
  17. 17. Model Results; transect-averaged results Delft3DUserDays2019 17
  18. 18. Sediment Pathways Interactive visualization Tool (SPIT) Background • We often use streamlines as a Lagrangian way to visualize steady Eulerian fluid flow fields Can we get more out of these model results? Delft3DUserDays2019 18
  19. 19. Streamlines • But what happens when the flow field is constantly changing? • We can represent it with the mean field over a given period and compute streamlines from that Delft3DUserDays2019 19
  20. 20. • We can visualize Lagrangian pathways that idealized particles would travel as they pass through the changing vector field 1. Use current velocity field to move particles passively through the domain 2. Use current velocity field plus add rules governing the active motion of particles • Larval swimming behavior • Entrainment/settling thresholds based on critical shear stresses e.g. Delft3D-PART (Deltares, 2015) or PTM (McDonald et al, 2006), Mdrift This approach often greatly simplifies the processes influencing sediment transport 3. SPIT uses sediment transport vector fields instead of current velocity to advect particles 4. SPIT is a post-processing routine (matlab) that uses the existing model output of Delft3D Lagrangian representations of Eulerian flow fields Delft3DUserDays2019 20
  21. 21. Lagrangian representations of Eulerian flow fields • Release 500 particles in the domain • Compute the trajectories over a given time interval e.g. 1 month or 1 year. • The final end result: SPAGHETTI? • Colors indicate wave directions • Red = from the north-west • Yellow = from the west • Green = from the southwest Delft3DUserDays2019 21
  22. 22. • We can visualize Lagrangian pathways that idealized particles would travel as they pass through the changing vector field 1. SPIT uses sediment transport vector fields instead of current velocity to advect particles 2. SPIT is a post-processing routine (matlab) that uses the existing model output of Delft3D 3. SPIT results allow us to visualize the sediment transport pathways Lagrangian representations of Eulerian flow fields Delft3DUserDays2019 22
  23. 23. Wave height Sediment trajectories (circles denote starting locations) • Constant wave forcing • Morphologic tide Delft3DUserDays2019 23
  24. 24. Particles released within the NH permit area If the particles move, most seem to reach Long Beach, with some arriving at Benson Beach A few even make it to the navigation channel Colored arrows denote wave direction Delft3DUserDays2019 24
  25. 25. Benson Beach is mainly fed by the Peacock Spit Particles that pass through Benson Beach polygon Delft3DUserDays2019 25
  26. 26. The Navigation Channel is largely fed by upstream sources and the ebb-tidal delta Particles that pass through the navigation channel in the MCR Delft3DUserDays2019 26
  27. 27. Delft3DUserDays2019 27 Conclusions • Applied to MCR, SPIT allows for evaluation of dredge placement and its effects on the coast/littoral cell • Sediment transport pathways form an important element in the coastal system, but are usually not studied or analyzed • New analysis technique (SPIT) was developed to better understand Sediment Transport pathways • SPIT is NOT a tracer but a Lagrangian visualization of an Eulerian vector field • Tools like SPIT allow us to obtain more information from our model results • Tools like SPIT combined with animations and visualizations allow us to better communicate complex model results

×