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Why do we need to know about Rivers?
• Source of drinking water• Source of irrigation water (You eat rivers as well
as drink them)• Waste removal (takes it downstream)
– A given pollutant can settle out within 30 feet of flowing over rock and sand.
• Industry – you like electricity?• Flood Control – you like your house dry?• Recreation• Wildlife Habitat
Texas River Basins
With topographic relief added…
Rivers in Texas – Common Denominators
• All flow in Southeasterly direction
• All empty into Gulf of Mexico
• Otherwise – EXTREMELY variable in their characteristics!
All the Rivers of Texas
Primary Watersheds1. Sabine2. Neches3. Trinity4. San Jacinto5. Brazos6. San Bernard7. Colorado8. Navidad9. Atascosa10. San Antonio11. Guadalupe12. Aransas13. Nueces
The Rio Grande and its Tributaries• Rio Grande• Pecos• Devils
Tributaries of the Mississippi• Canadian • Red • Cypress• Sulphur
WatershedWhat is a Watershed?
A watershed is the area of land where all of the water that is under it or drains off of it goes into the same place. John Wesley Powell, scientist geographer, put it best when he said that a watershed is:
"that area of land, a bounded hydrologic system, within which all living things are inextricably linked by their common water course and where, as humans settled, simple
logic demanded that they become part of a community." Watersheds come in all shapes and sizes. They cross county, state, and national
boundaries. In the continental US, there are 2,110 watersheds; including Hawaii Alaska, and Puerto Rico, there are 2,267 watersheds.
River Zones
• Zone # 1: Headwaters
• Zone # 2: Transition
• Zone # 3:Flood Plains
Zone # 1: Headwaters
• Water rises out of springs
• Water typically cooler
• Waterfalls, rapids, make for high DO
• Lifeforms: trout, members of Order Ephemeroptera.
Headwaters videos
http://www.youtube.com/watch?v=ldg6Sru0ddgIn Transit Mississippi River by canoehttp://www.youtube.com/watch?v=JJ6WB3lKMHo&feature=list_related&playnext=1&list=SPE2907D7AA81F6571
Zone #2: Transition Zone
• Formed where headwaters merge
• Wider, deeper, gentler flow
• Lower DO
• Shape land by incising valleys
• Lifeforms: Crappie, Crayfish
Transition Zone Videos
http://www.youtube.com/watch?v=y8UfH1Eo5bE
http://www.youtube.com/watch?v=zQQngZ-M6II
Zone #3: Flood Plains
• Streams join to form deep, wide rivers that MEANDER across broad, flat valleys.
• Higher temperatures• Lower DO• Shape land by cutting
meanders, laying out deltas, depositing levees and floodplains.
• Lifeforms: Catfish, tolerant “Macs”
Floodplain Videos
http://www.youtube.com/watch?v=RQ6oyf9C8Lc&feature=results_main&playnext=1&list=PL6D35E13D8E3608B9
Zone # 4: Delta
• Stream meets the sea or lake and dumps its load, forming a broad plain called a DELTA.
• Nutrient RICH, often influenced by tides, variable salinity
• These factors allow for an extremely rich smorgasbord of fish and invertebrates: – Freshwater and Inshore
Saltwater species (Alligator Gar, Red Drum) cohabitate.
Delta Videos
http://www.youtube.com/watch?v=SJLg_Fabuok
http://www.youtube.com/watch?v=Hi6x0951H7A
http://www.youtube.com/watch?v=RFDYfvahEwE
How to Kill a River• Pollution (Point Source)
– Sewage– Industrial Wastes(Non-point Source)– Agricultural Fertilizers– Runoff from Roads (Oil scum)– Plastics(Biological)– Alien species
• Over – damming– Kills the flow, upsets local fisheries. – Starves ocean of sand, leading to erosion of coastal features.
• Channelization• River Sediment Mining
More Must-see Videos
Non-point Source Pollution
http://www.youtube.com/watch?v=cACFw8lzkPI
http://www.youtube.com/watch?v=eozVMJCYHCM&feature=related
Dynamic Equilibrium
http://www.youtube.com/watch?v=0Va7E7KOz94&feature=related
More Good Stuff
• http://www.youtube.com/watch?feature=player_embedded&v=0fIXhs6DzIE#!