A case history: Galveston, Texas, on Sept. 8th 1900 and now.

View of Galveston, with breakwaters, seawall and buildings built on raised plaform.

Factoids on 1900 storm:

View of Hotel Galvez from breakwater made of granite blocks. The thin beach and the seawall are also evident.

What basic forces are involved in shaping shorelines?

Myriad of shoreline types - will look at three general types.

• deltas.
• barrier island complexes.
• cliffs.

• three end member types: river, wave, tide dominated.
• the Mississippi delta, lobe progradation -> lobe switching, and the Atchafalaya pirate.
• compaction, subsidence, flooding, mass wasting, shifting channels and ecosystems
• flooding on the Bangla Desh delta: in last 30 years typhoons have caused over 300,000 fatalities.

• examples: from Hilton Head to Padre Island.
• some components: shoreface, dune berm, washover fans, tidal channels, tidal deltas, offshore sand bars, lagoonal area.
• presently characterized by erosion. Rates?
• how does sand move? This is key to many environmental problems.
• how can barrier island change with time?
• how do you determine and what are rates of shoreline retreat and what are rates?
• the importance of hurricanes.
• what are possible causes of shoreline retreat?

• California and mass wasting triggered by slope profile steepening.

What is an alternate approach to shifting and flooded shorelines?

Some links to explore more:

Extensive USGS study of El Niño Coastal Erosion along California.

State of Texas Coastal Erosion Planning and Response.

Study on risk analysis and management for coastal erosion and catastrophic storms.

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