Why do we need to know about Rivers? Source of drinking water Source of irrigation water (You eat...

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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

Why do we need to know about Rivers? Source of drinking water Source of irrigation water (You eat...

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