200 likes | 290 Views
Climate Impacts on Washington’s Coasts. Dr. Daniel Huppert School of Marine Affairs, UW. Organization of Talk. Overview of Sea Level Rise Erosion of beaches and bluffs Impacts on Shellfish Impacts on Ports.
E N D
Climate Impacts on Washington’s Coasts Dr. Daniel Huppert School of Marine Affairs, UW
Organization of Talk • Overview of Sea Level Rise • Erosion of beaches and bluffs • Impacts on Shellfish • Impacts on Ports
WA has 5000km of coast (3085 mi.), including Puget Sound, 300 islands, & 2 major bays
Beaches, Sand Spits & Bluffs The most prevalent shore type in Puget Sound is the bluff-backed beach – coastal bluffs fronted by narrow mixed sand and gravel beaches.(Johannsssen and MacLennan 2007)
Sea walls, riprap, or revetments protecting beaches reflect wave energy, causing increased erosion of adjacent beach
Bainbridge Island (Pt Munroe) • 82% of shoreline is residential, commercial, or industrial use • 48% is armored • How to accommodate SLR?
Shorelines are relatively well protected within the SW Wash. bays • Willapa Bay and Grays Harbor
Bluff Erosion in Puget Sound • Feeds sediment for beach formation but also threatens property and human lives • The steepening of bluff slopes increases the probability of bluff failure • Key factors are storms with large waves, especially when combined with high tides or elevated sea levels
Western Whidbey Island • Erosion rates range from 1cm to more than 61cm (2ft) per year • CC will increase the rate of erosion
San Juan Islands • Very little bluff erosion • Composed mainly of exposed bedrock coast • Unlikely that an increase in SLR will affect the bluff erosion patterns
Adaptation Options • Accommodation - raise docks • Protection - Sea walls, dikes • Retreat • Moving or building on higher ground • rolling easements
Impacts on Ports • Shoreline facilities susceptible to inundation with SLR. • Both Tacoma and Seattle ports have some plans to raise docks & piers • Broader problem is flooding of neighboring lands and transportation routes - highways and rail lines. • Solutions require broad planning