Engineering for Climate Coastal Engineering Methods for Resilient Atoll Nations in Productive Oceans Presented to Asian Development Bank (ADB), Maldives By: Michael J.H. Foley, Ph.D., P.E. August 28, 2019 Welcome to Our Future Climate 10/8/19 2 Beach & Shoreline Erosion Mitigation Protecting Against Sea Level Rise Nature-Based Designs to Restore Eroded Shorelines & Enhance Coastal Resilience • Engineering • Design • Ecosystems • Technology 3 Land Subsidence Drivers of Coastal Erosion Rainfall Betio Runoff Currents Wave Runup Bairiki Rising Sea Levels 4 Sea Level Rise Increases Shoreline Wave Heights and Flooding Beach Reef Crest Reef Flat Forereef Sea Level Rise Bad for Atoll Islands Reef Crest Reef Flat Lagoon Forereef Mitigation of Erosion Hazards Adaptation Managed Retreat 10/8/19 7 Mitigation of Shoreline Erosion Armored Slopes Vertical Walls 10/8/19 8 Beaches Natural Erosion Protection 10/8/19 9 Mitigation of Beach & Shoreline Erosion Sand Nourishment Vegetated Coastal Berm Before After 10/8/19 10 Beach Stabilization Groins Breakwaters 10/8/19 11 Design by Nature – Beach Stabilization 10/8/19 12 Crescent Beaches Natural Biomimicry Crescent Engineered Beach Lagoon Crescent Beach Natural Lagoon Source: Google Earth Waves Move Sand Long-Shore Sediment Transport Cross-Shore Sediment Transport Source: Google Earth Source: Google Earth Wave Reef Interactions - Refraction Swell Deep Submerged Reef Water Channel Rotated Wave Crest Submerged Reef Waves Slow, Rotate and Converge Swell Wave Energy Diverted Source: Google Earth Source: Google Earth Wave Structure Interactions - Diffraction Wrapped Waves Wrapped Waves Opening Swell Obstruction Opening Swell Obstruction Source: Google Earth Source: Google Earth Beach Formations Salient Tombolo Emerging Reef Waves Refract & Diffract Submerged Reef Swell Headland Waves Shoal & Break c Source: Google Earth 17 Living Reefs for Coastal Protection Living Reef Beach Reef Crest Reef Flat Forereef Design of Living Reefs • Wave Dissipation – Coastal & Harbor Protection – Beach & Shoreline Stabilizing • Ecosystem Habitat – Sand Production – Marine Resources • Recreational Use – Diving – Surfing – Tourism 10/8/19 19 Design by Nature – Living Reefs High Wave Energy Structural Stability 10/8/19 20 Design by Nature – Reef Topography Macro Scale Micro Scale 10/8/19 21 Design by Nature - Reef Structure High Wave Energy Flat Coral Morphology 10/8/19 22 Reef Morphology Calm Energy Environment Branching Coral Morphology 10/8/19 23 Design by Nature – Ecosystem Habitat Macro Scale Micro Scale 10/8/19 24 Design by Nature – Living Reef Economically Viable Construction Materials & Surface Texture 10/8/19 25 Design by Nature – Living Reef Natural Biomimicry 10/8/19 26 Living Reefs A Strategy for Atoll Islands Sand Fill Living Reef Reef Crest Reef Flat Forereef Lagoon Monitoring a Changing Environment Waves & Currents Shoreline Surveys Erosion Data iBeach Computer Vision: Using computers To automate tasks That the human visual system can do To gain high-level understanding from Digital images or Videos 29 10/8/19 30 10/8/19 31 Numerical Simulation of Wave Patterns Design Verification Existing: Proposed : Coastal Restoration and Sea Level Rise Protection Existing Eroding Coastline Potential Restoration Scheme Protection Beach Fishing Shoreline No Diving Hazards Beach Reef Surfing 10/8/19 Dr. Michael Foley Coastal Engineer (808) 954-4184 [email protected] https://myibeach.com/ 10/8/19 35.