Energy Attenuation & Hybrid Living Shorelines: A Viable Tool for ...
Energy Attenuation & Hybrid Living Shorelines: A Viable Tool for Coastal Resilience Hot Topic Session
Delaware Estuary Science & Environmental Summit “Balancing Progress & Protection – 10 Years of Science in Action” January 25-28, 2015 Cape May, New Jersey
Douglas Janiec Natural Resources Program Manager & Senior Restoration Ecologist Sovereign Consulting, Inc. Photograph provided by Living Shoreline Solutions, Inc.
What does a Hybrid Living Shoreline do? A Hybrid Living Shoreline creates a multi-step wave energy attenuation system by mimicking natural processes. They provide the following benefits: •Supports LS Projects in Moderate to •Barrier Reefs High Energy Systems •Oyster Habitat •Sediment Conservation •Stabilizes Beaches for Horseshoe •Cost Saving for Dune and Crab and Migratory Birds Nourishment Projects •EFH Uplift •Infrastructure Protects
•Sea grass/SAV Restoration
•Resilience (50+ years) Page 2
Natural Energy Attenuation System (concept cross section)
(mixed dune/beach/marsh/flat system) Arrows Represent Wave Energy
Existing Beach
MHW MLW Natural Accretion Zone (may be beach, marsh, intertidal bars, and/or SAV)
Dune, high marsh edge, forest, or other supratidal feature Step 3 (severe storm) Attenuation
00
100
Bottom w/o Irregular Feature
Step 2 (lower energy) Attenuation
200
300
400
500 600 Example of Spacing (ft)
Feature (i.e. land, sand bar, reef, wide shallows, structure) Step 1 (higher energy) Attenuation
700
800
900
Hybrid Energy Attenuation System (concept cross section)
Targeted Resilient Shoreline (mixed dune/beach/marsh/flat system) Existing Beach
MHW MLW Existing supratidal feature gets hammered
Most or all of Step 2 is absent
Step 3 (severe storm) Attenuation
00
100
Step 1 is gone
Existing Bottom
Step 2 (lower energy) Attenuation
200
300
400
500 600 Example of Spacing (ft)
Step 1 (higher energy) Attenuation
700
800
900
Hybrid Energy Attenuation System (concept cross section)
Targeted Resilient Shoreline (mixed dune/beach/marsh/flat system) Existing Beach
MHW MLW Created or existing supratidal feature
Passive accretion and/or optional nourishment (may be beach, intertidal bars, and/or some SAV)
Step 3 (severe storm) Attenuation
00
100
Hybrid Structure (n.t.s.)
Existing Bottom
Step 2 (lower energy) Attenuation
200
300
400
500 600 Example of Spacing (ft)
Step 1 (higher energy) Attenuation
700
800
900
Wave Constructive (in phase) Conditions & Destructive Wave (out of phase) Conditions
In Phase
Out of Phase
Page 6
Some Wave Basics
The longer the wind blows - the bigger the waves The stronger the winds – the higher the waves The longer the fetch - the bigger the waves Substrate depth and slope affect wave type and break Relative to the Delaware Bay, these factor limit wave size and energy. Page 7
How Wave Energy Interacts with Objects (BBW) Reflection (bouncing)
Refraction (bending)
Diffraction (wrapping)
Page 8
An Example
Shoreline Erosion Area
Constructive Wave Energy Redirectioning and Focusing
Destructive Wave Condition
Wave Diffraction Apollo Bay, AU
Breakwaters & Hybrid Living Shorelines Are Functionally Different Breakwaters provide a complete or partial linear barrier to redirect (manipulate) concentrated wave energy. New hybrid living shorelines allow the wave to pass through the structural array as the wave attenuates (breaks up) and creates a destructive wave environment.
Page 10
Examples of Breakwaters
Erosion Patterns (not accretion patterns). Although some attenuation occurs, much of the energy is still concentrated.
Fights with nature.
Example of Energy Attenuation: Cupped Wave Spreader – Loop Canal, Bethany Beach, DE Concentrated energy
Log Cups
Gap Logs Unconcentrated energy; suspended particuates drop out of column
Red is refractions over logs Purple is diffraction around logs Cumulatively, the combined wave manipulations result in energy cancellation and attenuation Thank you, Delaware Center for the Inland Bays for sharing
Page 12
Other Structural Energy Manipulations Energy Focusing/Defocusing Baffled opening in structures Strategic constrictions and enlargements Strategic placement of structures Energy Redirectioning X-Y Planar energy deflections (horizontal vector alterations) Z Planar energy deflections (vertical vector alterations) Microturbulence
Page 13
Example of Other Manipulations • Energy Focusing/Defocusing • Energy Redirectioning • Microturbulence
Figures provided by Living Shoreline Solutions, Inc.
Page 14
Energy Attenuation Technology at Work
Video provided by Living Shoreline Solutions, Inc.
Energy Attenuation Offers a New Options for Shoreline Resilience Wayfarers® (low to moderate energy)
Oyster Castles® (low to moderate energy)
WADs™ (moderate to high energy)
Thank You Douglas Janiec Natural Resource Program Manager Sovereign Consulting, Inc. 973-433-6480 [email protected]
A typical summer evening at the point
Delaware Estuary Science & Environmental Summit “Balancing Progress & Protection – 10 Years of Science in Action” January 25-28, 2015 Cape May, New Jersey
Douglas Janiec Natural Resources Program Manager & Senior Restoration Ecologist Sovereign Consulting, Inc. Photograph provided by Living Shoreline Solutions, Inc.
What does a Hybrid Living Shoreline do? A Hybrid Living Shoreline creates a multi-step wave energy attenuation system by mimicking natural processes. They provide the following benefits: •Supports LS Projects in Moderate to •Barrier Reefs High Energy Systems •Oyster Habitat •Sediment Conservation •Stabilizes Beaches for Horseshoe •Cost Saving for Dune and Crab and Migratory Birds Nourishment Projects •EFH Uplift •Infrastructure Protects
•Sea grass/SAV Restoration
•Resilience (50+ years) Page 2
Natural Energy Attenuation System (concept cross section)
(mixed dune/beach/marsh/flat system) Arrows Represent Wave Energy
Existing Beach
MHW MLW Natural Accretion Zone (may be beach, marsh, intertidal bars, and/or SAV)
Dune, high marsh edge, forest, or other supratidal feature Step 3 (severe storm) Attenuation
00
100
Bottom w/o Irregular Feature
Step 2 (lower energy) Attenuation
200
300
400
500 600 Example of Spacing (ft)
Feature (i.e. land, sand bar, reef, wide shallows, structure) Step 1 (higher energy) Attenuation
700
800
900
Hybrid Energy Attenuation System (concept cross section)
Targeted Resilient Shoreline (mixed dune/beach/marsh/flat system) Existing Beach
MHW MLW Existing supratidal feature gets hammered
Most or all of Step 2 is absent
Step 3 (severe storm) Attenuation
00
100
Step 1 is gone
Existing Bottom
Step 2 (lower energy) Attenuation
200
300
400
500 600 Example of Spacing (ft)
Step 1 (higher energy) Attenuation
700
800
900
Hybrid Energy Attenuation System (concept cross section)
Targeted Resilient Shoreline (mixed dune/beach/marsh/flat system) Existing Beach
MHW MLW Created or existing supratidal feature
Passive accretion and/or optional nourishment (may be beach, intertidal bars, and/or some SAV)
Step 3 (severe storm) Attenuation
00
100
Hybrid Structure (n.t.s.)
Existing Bottom
Step 2 (lower energy) Attenuation
200
300
400
500 600 Example of Spacing (ft)
Step 1 (higher energy) Attenuation
700
800
900
Wave Constructive (in phase) Conditions & Destructive Wave (out of phase) Conditions
In Phase
Out of Phase
Page 6
Some Wave Basics
The longer the wind blows - the bigger the waves The stronger the winds – the higher the waves The longer the fetch - the bigger the waves Substrate depth and slope affect wave type and break Relative to the Delaware Bay, these factor limit wave size and energy. Page 7
How Wave Energy Interacts with Objects (BBW) Reflection (bouncing)
Refraction (bending)
Diffraction (wrapping)
Page 8
An Example
Shoreline Erosion Area
Constructive Wave Energy Redirectioning and Focusing
Destructive Wave Condition
Wave Diffraction Apollo Bay, AU
Breakwaters & Hybrid Living Shorelines Are Functionally Different Breakwaters provide a complete or partial linear barrier to redirect (manipulate) concentrated wave energy. New hybrid living shorelines allow the wave to pass through the structural array as the wave attenuates (breaks up) and creates a destructive wave environment.
Page 10
Examples of Breakwaters
Erosion Patterns (not accretion patterns). Although some attenuation occurs, much of the energy is still concentrated.
Fights with nature.
Example of Energy Attenuation: Cupped Wave Spreader – Loop Canal, Bethany Beach, DE Concentrated energy
Log Cups
Gap Logs Unconcentrated energy; suspended particuates drop out of column
Red is refractions over logs Purple is diffraction around logs Cumulatively, the combined wave manipulations result in energy cancellation and attenuation Thank you, Delaware Center for the Inland Bays for sharing
Page 12
Other Structural Energy Manipulations Energy Focusing/Defocusing Baffled opening in structures Strategic constrictions and enlargements Strategic placement of structures Energy Redirectioning X-Y Planar energy deflections (horizontal vector alterations) Z Planar energy deflections (vertical vector alterations) Microturbulence
Page 13
Example of Other Manipulations • Energy Focusing/Defocusing • Energy Redirectioning • Microturbulence
Figures provided by Living Shoreline Solutions, Inc.
Page 14
Energy Attenuation Technology at Work
Video provided by Living Shoreline Solutions, Inc.
Energy Attenuation Offers a New Options for Shoreline Resilience Wayfarers® (low to moderate energy)
Oyster Castles® (low to moderate energy)
WADs™ (moderate to high energy)
Thank You Douglas Janiec Natural Resource Program Manager Sovereign Consulting, Inc. 973-433-6480 [email protected]
A typical summer evening at the point
