1 / 45

Floodplain Management SESSION 2

Floodplain Management SESSION 2. Stream Systems on Dynamic Earth Geologic Framework Prepared By Donald R. Reichmuth, PhD. Geologic Framework. Objectives: Define Floodplains Describe Stream System Functions Explain Tectonic Plates Explain Vertical Plate Motion

maura
Download Presentation

Floodplain Management SESSION 2

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Floodplain ManagementSESSION 2 Stream Systems on Dynamic Earth Geologic Framework Prepared By Donald R. Reichmuth, PhD.

  2. Geologic Framework Objectives: Define Floodplains Describe Stream System Functions Explain Tectonic Plates Explain Vertical Plate Motion Identify Tectonic Domains Summarize Glacial Behavior Compare Erosion Related Processes

  3. River Basin Definition A region or area bounded by a topographic divide that contributes water to a particular stream channel (corridor) or other water body.

  4. Floodplain Definition That portion of a Drainage Basin that is covered by Transported Sediment that was deposited in or near a stream channel.

  5. FUCTIONS OF RIVER SYSTEMS • Removes Erosional Debris • Most Important • Acts Over Long Periods • Removes Excess Water • Importance Secondary • Acts Sporadically Over Short Periods • Provides Fresh Water Supply • Necessary To Sustain Life • Transports Chemicals & Nutrients

  6. Geologic Framework • Tectonics • Passive Margins • Stable Platforms • Active Margins • Hot Spots • Glaciation • Alpine Glaciers • Continental Glaciers • Geomorphology • Surface Forming Processes • Water • Ice • Gravity • Wind

  7. Present Plate Boundaries

  8. Stream Systems on Dynamic Earth BASIC TYPES OF PLATE INTERACTION

  9. North America Structure • Craton • Shield • Stable Platform • Mobile Belts Tectonic Activity • Active Margin • Passive Margin

  10. Karst TopographyExample • Solution Cavities In Limestone • Streams Have Subsurface Connections

  11. Cretaceous Inland Sea100 Million Years Ago

  12. Vertical Plate Motion Causes: Tectonic/Earthquake Activity Erosion & Sediment Loading Glaciation Human Activities

  13. Uplift Example

  14. Himalayan Data Present Height --- 30,000 Ft (9,500 m) Tectonic Uplift Rate --- More Than 1 cm/yr Erosion Rate --- Now Equals Uplift Rate Sediment Yields Highest Known

  15. Worldwide Erosion Rates

  16. Oceanic-Continental Convergence Oceanic Crust Subducts Ocean Trench Forms Lighter Melted Material Rises Volcanoes Form Lithosphere Plunges Into Asthenosphere

  17. Effects Of Plate Locking

  18. Effects Of Erosion

  19. Man Induced Vertical Movement

  20. Ongoing Elevation Changes

  21. Active Margin Note: • Aleutian Trench • Canada • Strike-Slip Faulting • Mobile Belt Deposits • California • Strike-Slip Faulting

  22. Active Margin • Ocean-Continent Subduction • Strike Slip Faulting

  23. Hot Spot Locations

  24. Hawaiian Hotspot

  25. Passive Margin • Coastline Sinking • Drowned River Valleys • Numerous Near-shore Islands • Shoreline Migrating Landward

  26. Northern Hemispheric GlacialAreas16,000 B.P. NOTE: Portions Of Alaska Are Ice Free

  27. Pleistocene Glaciation Note: • Alpine Glaciers • Continental Glaciers • Ice Marginal Rivers • Alaska Ice Free Area

  28. Glacial Impact Areas

  29. Preglacial Teays Basin Teays Basin Overrun By Ice Channel Buried Ohio River Forms Drains Basin

  30. Western Glacial Lakes 15,000 B.P. • Climate Much Wetter Than Present • Large Basins Had Internal Drainage

  31. Loess Wind Blown Silt From Glaciers Rock Flour Stream Banks Stand Vertical When Stable

  32. Glacial ReboundContours In Meters Uplift

  33. Great Lakes Glacial ReboundContours – Uplift per 100 Yrs.

  34. Sea Level Changes 16,000 Years BP -- 120 Meters Lower 6,000 Years BP – Reached Present Level Near Future – Expected To Rise

  35. HoloceneSea Level Changes Primarily Cause --- Glacial Melting In The Northern Hemisphere

  36. Erosion In River Basins Controlling Factors: • Chemical vs. Mechanical Weathering • Temperature • Precipitation • Basin Gradient • Basin Soil/Bedrock Type • Tectonic Activity

  37. Chemical & Mechanical Weathering

  38. Erosion Processes

  39. Erosion Processes

  40. Mass Movements

  41. Class Handout

  42. CASE STUDIES • Columbia River • Mississippi River • Ohio River • Potomac River • Red River of the North • Rio Grande River • Santa Ana River

  43. Geologic Setting

  44. JURISDICTION & CONCERNS

  45. Slide PresentationPrepared ByGeomax, P.C.Dr. Donald R. Reichmuth, President1023 W. 30th Ave.Spokane, WA 99203-1324Phone & FAX – 509-838-6390E-mail – geomax@comcast.net

More Related