1. Design Sequence Economics: is the port economically justified?
Site Selection: Where should the Port be developed

2. Coastal Geomorphology
Study of Coastal Landforms, Their Origin and Evolution and the Processes That Shape Them

3. References for Site Selection
Nautical charts: Best for coastal navigation and underwater features
Topographic (quad) Maps: Best for uplands
Aerial photography (including “google Earth” satellite imagery: Good for land features and upland development

4. Coastal Features

5. Sediment Budget LOSSES GAINS Longshore Transport Longshore Transport
Offshore Bars
Sediment Budget
Rivers
Sediment Budget
Offshore Deep Water
Cliff and Berm Erosion
Offshore Bars
Onshore Wind Transport
Beach Nourishment
Beach Mining

6. Sediment budget 2 Sediment Budget Longshore Transport Cliff Erosion
Offshore Sand Bars
Cliff Erosion
Longshore Transport

7. Spit (sediment sink)
Erosion
Deposition

8. Cliff Erosion Primary Causes: Wind & Rain Freeze Thaw
Waves (high water)

9. Be careful using old charts
1984
Is the spit in a stable equilibrium?
1990
Or is it eroding?

10. Alluvial Fans Caution:
Created by river sediments deposited into deepwater.
Characterized by relatively flat inter tidal zone and steep rounded outer face. Outer face is usually close to angle of repose (about 2H:1V).
Typically comprised of uniform sand and gravel suitable for construction including dredging and pile driving.
Caution:
River sediments need to be factored into design.
Alluvial fans can have high risk of failure during seismic events.

11. Alluvial Fans

12. Alluvial Fans
Before 1964 Earthquake
Currently
New Cruise Ship Dock

13. Glacial – Terminal & Lateral Moraines Blackstone Bay

14. Be sure to read the Charts

15. Cuspate Bar:
From 84 SPM Appendix A

16. Point Hope North Shore Eroding at 10’ per year
South Shore accreting at 10’ per year

17. Effect of Coastal Structures
Accretion
Erosion

18. 1000’

19. Delong Mountain Terminal (Red Dog)
Erosion
Original Shoreline
Accretion
Delong Mountain Terminal (Red Dog)

20. Offshore bars
Strong Longshore Currents
Offshore Bars

21. Most Charts soundings are Fathoms but not always
Note: “Feet” not “Fathoms”
Most Charts soundings are Fathoms but not always

22. Port of Anchorage

23. Headlands
Headlands will often have shallow bedrock. Look for irregular contours. Generally higher and steeper shorelines with more difficult onshore access.

24. Pocket Beaches
Pocket Beaches: Situated between headlands. Generally deep deposit of sand & gravel. Easy dredging and pile driving but very active sedimentation.

25. Areas of Environmental Sensitivity
Kelp
Eel Grass
Other Submerged Aquatic Vegetation (SAV)

26. Homework 1 CE A675
1.Using the Chart for Akhiok Island (black & white copies):
Identify all the sediment sources (red)
Identify all the sediment sinks (blue)
Areas of difficult construction (rocky)
Areas of easy construction (sand & gravel)
Areas that would be environmentally sensitive (green)
2. We are going to place a fuel storage tank on the island and need to service it with a 400’ long self propelled barge with a 15 foot loaded draft. Show a good location for constructing a dock of a similar length and sketch it in. Allow 3 feet under keel at mllw. Assume prevailing wind & waves are from the South (Bottom of Page). Provide a one page (maximum) write up explaining your Selection.

27. Homework 1 chart

28. Homework 1 CE A675
Using the attached charts of Homer Spit discuss it formation and how it evolved. Is it really a spit or perhaps a terminal moraine or some other type of feature?