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Floodplain Management SESSION 2. Stream Systems on Dynamic Earth River Basins & Tectonics Prepared By Donald R. Reichmuth, PhD. River Basin & Tectonic Framework. Objectives: 1 Major landscape parameters that are involved in Floodplain Management.
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Floodplain ManagementSESSION 2 Stream Systems on Dynamic Earth River Basins & Tectonics Prepared By Donald R. Reichmuth, PhD.
River Basin & Tectonic Framework Objectives: 1 Major landscape parameters that are involved in Floodplain Management. 2 Four fundamental functions of stream systems. 3 Size, shape, structure, and location of the major tectonic plates affect stream behavior. 4 Vertical plate motion affects sediment production. 5 Regional tectonic domains in the United States and their affect on floodplains. (Optional Objective) 6 Select a course case study exercise and form teams.
Floodplain Definition That portion of a Drainage Basin that is covered by Transported Sediment that was deposited in or near a stream channel.
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. --------------------------------------------------- Sometimes called a “catchment” or a “watershed”.
FUNCTIONS 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
Geologic Framework Tectonics • Passive Margins • Stable Platforms • Active Margins • Hot Spots
Stream Systems on Dynamic Earth BASIC TYPES OF PLATE INTERACTION
North America Structure • Craton • Shield • Stable Platform • Mobile Belts Tectonic Activity • Active Margin • Passive Margin
Karst TopographyExample • Solution Cavities In Limestone • Streams Can Have Subsurface Connections
Vertical Plate Motion Causes: • Tectonic/Earthquake Activity • Erosion & Sediment Loading • Glaciation • Human Activities
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
Oceanic-Continental Convergence Oceanic Crust Subducts Ocean Trench Forms Lighter Melted Material Rises Volcanoes Form Lithosphere Plunges Into Asthenosphere
Active Margin Note: • Aleutian Trench • Canada • Strike-Slip Faulting • Mobile Belt Deposits • California • Strike-Slip Faulting
Active Margin • Ocean-Continent Subduction • Strike Slip Faulting
Passive Margin • Coastline Sinking • Drowned River Valleys • Numerous Near-shore Islands • Shoreline Migrating Landward
Uplift ForcesEarth’s Internal Heating ProvidesEnergy To Cause Surface UpliftErosion Can Then Proceed
CASE STUDIES Columbia River Mississippi River Ohio River Potomac River Red River of the North Rio Grande River Santa Ana River
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