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. 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
Present Plate Boundaries
BASIC TYPES OF PLATE INTERACTION
Stream Systems on Dynamic Earth
North America
Structure
– Craton
• Shield • Stable Platform
– Mobile Belts
Tectonic Activity
– Active Margin – Passive Margin
Karst Topography
Example
• Solution Cavities In Limestone • Streams Can Have Subsurface Connections
Cretaceous Inland Sea
100 Million Years Ago
Vertical Plate Motion
Causes:
• • • • Tectonic/Earthquake Activity Erosion & Sediment Loading Glaciation Human Activities
Uplift Example
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
Worldwide Erosion Rates
Oceanic-Continental Convergence
Oceanic Crust Subducts Ocean Trench Forms Lighter Melted Material Rises Volcanoes Form Lithosphere Plunges Into Asthenosphere
Effects Of Plate Locking
Effects Of Erosion
Man Induced Vertical Movement
Ongoing Elevation Changes
Active Margin
Note:
• Aleutian Trench
• Canada
– Strike-Slip Faulting
• Mobile Belt Deposits • California
– Strike-Slip Faulting
Active Margin
• Ocean-Continent Subduction
• Strike Slip Faulting
Hot Spot Locations
Hawaiian Hotspot
Passive Margin
• Coastline Sinking
– Drowned River Valleys – Numerous Nearshore Islands – Shoreline Migrating Landward
Uplift Forces
Earth’s Internal Heating Provides Energy To Cause Surface Uplift
Erosion Can Then Proceed
CASE STUDIES
Columbia River Mississippi River Ohio River Potomac River Red River of the North Rio Grande River Santa Ana River
Geologic Setting
RIVER BASIN
Tectonic
COLUMBIA RIVER
(Refer to Handout)
Water Sediment
Considerable Bedrock Control, Average Sediment Production
GEOLOGIC SETTING
Glacial Outlet
Pacific Ocean, Glacial Flood Deposits Off Coast, Northern Shore Current Dominant Gulf Of Mexico, Large Marine Fan-delta, Westward Coastal Circulation
(INCLUDING ROCKY MTN. TRENCH, Active Margin, Subducting Plate, Alpine Glaciation, Lake Missoula Significant SnowSNAKE RIVER, WILLAMETTE Flood Basalts Shifted Channel Floods, Bonneville Flood pack, Dryer Summers RIVER, COLUMBIA RIVER BAR & LONG BEACH)
MISSISSIPPI RIVER
(INCLUDING MISSOURI RIVER & LOUISIANA DELTA)
Passive Margin, Stable Midcontinent Shelf, Coastal Zone Sinking
Major Glacial Meltwater Channel, Heavy Lowland Large Quantities Of Fine Strong Impact From Low Glacial Spring Runoff, Heavy Sediment And Dissolved Sea Level Rainfall At Times Solids
OHIO RIVER
(INCLUDING TEAYS RIVER, MONONGAHELA RIVER & ALLEGHENY RIVER)
Stable Mid-continent, Heads In Old Eroded Allegheny Mtns., Crosses Stable Mid-continent Sedimentary Shelf
Ice Marginal Channel Built From Pieces Of Numerous Drainages
Significant Spring Runoff, Above Average Precipitation
Below Average Because Of Low Elevation And Good Vegetative Cover
Flows Into Mississippi River, Can Have Flood Synchronization Problems
Passive Margin, Heads In Old Eroded Allegheny Mtns., Crosses Originally Graded To Low Glacial Into Sinking Sedimentary (INCLUDING CHESAPEAKE BAY & Sea level Coastal Shelf, Impacted By A DELMARA PENINSULA) Meteor
POTOMAC RIVER
Above Average Precipitation
Below Average Because Of Low Elevation And Good Vegetative Cover
Atlantic Ocean, Submerged River Valley, Northern Coastal Circulation.
RED RIVER OF THE NORTH
(INCLUDING LAKE WINNIPEG & HUDSON BAY)
Stable Mid-continent, Flows From Sedimentary Shelf OnTo Continental Craton
Originates In Glacial Lake Agassiz, Flows North Against Glacially Induced Crustal Rebound Centered Near Hudson Bay, Stream Gradient Lowering
Rapid Spring Lowland Snowmelt Occasionally Mixed With Rain
Fine Grained Derived From Old Glacial Lake Bed
Hudson Bay That Has Uplifted Over 100 Meters Since The Last Glaciation
RIO GRANDE RIVER
(INCLUDING ELEPHANT BUTTE RESERVOIR, RIO PUERCO & PADRE ISLAND)
Active Uplift At Head (Mtn. Building), Mouth Sinking At Passive Margin
No Significant Glacial Impacts, Small Amount Of Alpine Glaciation At Head
High Fine Sediment Area Arid, Gulf Of Mexico, Northeast Production Caused By Significantly Higher Coastal Circulation Occasional High Intensity Precipitation During Strongly Influences The Storms And Scant Glacial Periods Stability Of Padre Island Vegetative Cover
SANTA ANA RIVER
(INCLUDING SAN BERNARDINO MTNS., PRADO WETLANDS, LOS ANGLES BASIN & HUNTINGTON BEACH) Active Margin, Strike-slip Faulting Very Active No Significant Glacial Impacts
Area Arid, High Fine Sediment Significantly Higher Production Caused By Precipitation During Occasional High Intensity Glacial Storms And Scant Periods,Water Vegetative Cover Imported Into Basin
Pacific Ocean, Southern Coastal Circulation Influences Huntington Beach
JURISDICTION & CONCERNS
(Refer to Handout)
RIVER BASIN
COLUMBIA RIVER
(INCLUDING ROCKY MTN. TRENCH, SNAKE RIVER, WILLAMETTE RIVER, COLUMBIA RIVER BAR & LONG BEACH) Washington, Oregon, British Columbia & Indian Nations Declining Salmon Populations Cominco Smelter (Canada) Numerous Large Dams, Hanford Nuclear Facility, Barge Traffic Conflict Developing Between Indian Nations & Newer Arrivals
JURISDICTION
Habitat
RECENT CONCERNS
Pollution Development
COMMENTS
MISSISSIPPI RIVER
(INCLUDING MISSOURI RIVER & LOUISIANA DELTA)
Midwestern States & Montana
Loss Of Channel Length, Disruption Of Sediment Transport
Agricultural Chemicals Entering River, Gulf Of Mexico "Dead Zone"
Levee Construction, Barge Traffic, Large Dams, Oil & Gas Drilling/Production
Conflict Developing Between Upper River States (Especially Along The Missouri) & Lower River States
OHIO RIVER
(INCLUDING TEAYS RIVER, MONONGAHELA RIVER & ALLEGHENY RIVER)
Pennsylvania, Ohio, West Virginia, Kentucky, Indiana & Illinois
Impacted By Industrial Use
Industrial Discharges, Acid Rain From Power Plant Emissions
Change In Vegetative Cover, Major Urban Growth In Valleys
Original Teays River Partially Buried During Glaciation
POTOMAC RIVER
(INCLUDING CHESAPEAKE BAY & DELMARA PENINSULA)
West Virginia, Virginia, Washington D.C. & Maryland
Bay Contains 160 Nonindigenous Species
Industrial Discharges, Urban Runoff, Salt Water Intrusion In Groundwater
Expanding Urbanization, Shoreline Construction
Demand For Domestic Water Supplies Becoming Critical
RED RIVER OF THE NORTH
(INCLUDING LAKE WINNIPEG & HUDSON BAY)
North Dakota, Minnesota, & Manitoba
Degraded By Agriculture
Agricultural Chemicals Entering River
Construction On The Management Requires Floodplain, Levee Construction Cooperaton Between Canada & Near Towns The U.S.
RIO GRANDE RIVER
(INCLUDING ELEPHANT BUTTE RESERVOIR, RIO PUERCO & PADRE ISLAND)
Colorado, New Mexico, Texas, Chihuahua, Coahuila, Nuevo Leon & Tamaulipas
Loss Of Fresh Water Access For Marine Species
Channel Heavily Dewatered Particularly In Lower Reaches
Dam Construction, Water Withdrawal For Agriculture, Sediment Filling Channel In Some Sections
Requires Water Allocation Between The United States & Mexico
SANTA ANA RIVER
(INCLUDING SAN BERNARDINO MTNS., PRADO WETLANDS, LOS ANGLES BASIN & HUNTINGTON BEACH)
California (Containing Cities & Counties Of The Los Angles Basin)
Channel Concrete Lined, Total Loss Of Cover
Sewer Outfalls Discharge Massive Urban Development In Into River, Salt Water Lowlands, Construction On Intrusion Into Groundwater, Steep Erosive Hillsides Fires In Upper Watershed
Water Imported From The Colorado River
Slide Presentation
Prepared By
Geomax, P.C.
Dr. Donald R. Reichmuth, President 1023 W. 30th Ave. Spokane, WA 99203-1324 Phone & FAX – 509-838-6390 E-mail – geomax@comcast.net