Rivers and Drainage
Dr. R. B. Schultz
Streams and Drainage
It is important that we make a review of the hydrologic cycle.
*97% of all water is oceans (salt water)
*2% of all water is in ice caps/polar ice
*0.6% is groundwater (fresh)
*0.2% is rivers and lakes (fresh)
*0.16% is atmospheric water (fresh)
Streams:
Gaining streams are those that take in water with time and tend to widen.
Losing streams are those that lose water with time and tend to become narrower.
Intermittent streams are those that are wet during the wet season and dry in
drier times.
There
• 1.
• 2.
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are several drainage patterns that develop based on rock type:
Dendritic -- branching
Radial -- associated with uplifts/hills
Rectangular -- associated with resistant rock
Trellis -- associated with resistant ridges
Drainage Types
There are several stages of stream development:
a.
Early (adolescent) -- waterfalls and rapids present
b. Middle (adult) -- widening floodplains
c.
Mature -- meandering streams present
d.
Old age -- very broad, wide valley, Yazoo stream tributaries and
oxbow lakes present
*Materials carried by the stream is referred to as bedload.
*The larger the particles, the less they are moved by water. Water
tends to round particles with time.
Three (3) types of materials in streams:
1. Bedload/Traction Load -- that which is heavy and pushed by the
water
2. Saltation – bouncing effect of grains
Suspended load -- that which is carried and bounced by the water
3. Dissolved -- actually dissolved in the water
Head of stream is starting point; mouth of stream is “end”.
Stages of Stream Development
Initial Stage:
Fast moving
stream, narrow
valley
Second Stage:
Meanders develop,
widening floodplain
Last Stage:
Wide floodplain,
yazoo streams, and
oxbow lakes
develop
*Channel shape is based on the velocity of the stream and resistance of rock it
is cutting into.
*Water in streams tends to move quicker in the center of the stream and
slower towards the outside.
*Wider streams move slower than narrow streams.
*Outside of meander is called a Cutbank and is associated with erosion.
*Inside of meander is called a Point Bar and is associated with deposition.
*Much (~45%) of the eastern portion of the U.S. is drained by the Mississippi
River, whereas the western portion of the U.S. is predominantly drained by
the Colorado River.
*The point between where drainage shifts is called a divide.
*As water from a river (stream) empties into a large body of water like an
ocean, it forms a structure called a delta.
*The Mississippi River emptying into the Gulf of Mexico is the type example of
a delta.
*Deltaic switching occurs when no more sediment can be added to a given area.
Thus, the river takes the path of least resistance and moves or migrates.
Cutbanks and Point Bars
Mississippi River Drainage Basin
Development of Delta
Deltaic Lobe Switching
Key Terminology
Gaining stream
Intermittent stream
Radial
Trellis
Traction load
Suspended load
Head
Floodplain
Oxbow lake
Cutbank
Divide
Deltaic lobe switching
Losing stream
Dendritic
Rectangular
Bedload
Saltation
Dissolved load
Mouth
Yazoo stream
Meander
Point bar
Delta
Drainage basin
Pertinent Web Sites
Dartmouth Flood Observatory
This Web site is a research tool for early detection, mapping, measurement, and analysis of extreme flood events worldwide using remote
sensing.
Disaster Finder (NASA)
A complete index to the best disaster Web sites on the Internet.
Discharge Data
United States Geological Survey (USGS) real-time and historical river discharge data by state.
Envirofacts (EPA)
Envirofacts is a single point of access to select U.S. EPA environmental data.
Environmental Protection Administration (EPA) Water Office
United States Environmental Protection Agency (EPA) Office of Water includes links to related federal and state agencies.
Flood Links
Links to various types of flood information.
Floodplain Management
Floodplain management from the Floodplain Management Association (FMA).
Global Hydrology and Climate Center (NASA)
The Global Hydrology and Climate Center (GHCC) is a joint venture between government and academia to study the global water cycle and
its affect on climate.
Hazards (USGS)
Information obout several types of environmental hazards from the United States Geological Survey (USGS).
Historical Streamflow Data (USGS)
Access to records of almost 19,000 stations that are part of the United States Geological Survey stream gaging network; some records go
back more than a century.
Hydrologic Calculations
Online hydrologic calculators from LMNO Engineering, Research, and Software, Ltd.
Hydrologic Remote Sensing Center
The National Operational Hydrologic Remote Sensing Center of the National Weather Service.
Hydrology Web
The Hydrology Web is a site that hosts a comprehensive list of links to Hydrology and related Hydrology resources.
International Rivers Network
The International River Network (IRN) supports local communities working to protect their rivers and watersheds. It works to halt destructive
river development projects, and to encourage equitable and sustainable methods of meeting the needs for water, energy and flood
management.
Landform Atlas of the United States
The color landform atlas of the United States includes shaded relief maps and satellite image maps of each state.
River Data Links
This Central Michigan University site maintained by Dr. Mark Francek lists several good links to websites containing information relative to
topics discussed in the chapter.
River Systems and Flooding
Excellent class notes on river systems and flooding from Tulane University.
Running Water Links (Houghton Mifflin)
Links to several running water sites, including class lecture notes, arranged by topic.
Stream and River Landforms
Text and images about how water shapes the land from the Geological Survey of Canada.
Streams and Mass Wasting Links (NAGT)
An extensive listing of streams and mass wasting links arranged by topic from the National Association of Geology Teachers (NAGT).
TopoZone
The TopoZone bills itself as the Web's center for recreational and professional topographic map users. Here you can interactively view
topographic maps from the entire United States.
Water Data, Real Time (USGS)
Real-time water data from the United States Geological Survey (USGS).
Water Pollution Links
This Central Michigan University site maintained by Dr. Mark Francek lists several good links to websites containing information relative to
topics discussed in the chapter.
Water Quality Information Center
The Water Quality Information Center collects, organizes, and communicates the scientific findings, educational methodologies, and public
policy issues related to water quality and agriculture.
Water Resources Links
This Central Michigan University site maintained by Dr. Mark Francek lists several good links to Web sites containing information relative to
topics discussed in the chapter.
Water Resources of the United States (USGS)
Information about water resources in the United States from the United States Geological Survey.
Watershed, Locate Your
This U.S. Environmental Protection Agency (EPA) site alllows you to locate and obtain information about the watershed you live
in, including a small map of the watershed.
Watershed Resources Links
An extensive listing of watershed links from the Global Rivers Environmental Education Network.
Water Resource Terms (Glossary of)
A glossary of water resource terms from the Edwards aquifer home page.
Water Use (USGS)
The National Water-Use Informational Program from the USGS.
World's Water, The
The World’s Water is a site dedicated to providing up-to-date water information and data, and web connections to
organizations, institutions, and individuals working on a wide range of global freshwater problems and solutions.