Water

Water Distribution

Water use in the US in 2000

The Water Cycle

Transpiration (plants)

Parts of a River

Collection Transportation Dispersal

Dendritic patternYemen

Limestone Bedrock:Naturally fractures into squares & rectangles

Common in the Appalachians where rivershave cut through parallel ridgelines.

Drainage Basin

Drainage Basin II

Delta Development

Distributary

Water coming down a river hits the ocean; gradient goes to zeroSediment is deposited; channel eventually fillsRiver jump its banks and takes a new courseProcess repeatsVery common in deltas

Distributaries

Mississippi River Delta

Mature Deltas

Mississippi Delta

Left to its own devices, theMississippi would now beflowing down the Atchafalaya Basin.

Oil refineries line the Mississippi

Atchafalaya River

Embankment

Mississippi

New Orleans

Hurricane Threat -- very real

Eroding defenses

Rivers are complex systems influenced by number of things, which are: - discharge - velocity - gradient - sediment load - base level

River Dynamics

Stream Discharge

- amount of water passing by a given point during a specific time interval

- measured in cubic meters/second

Discharge Station

Velocity

Meanders

Cut Bank

Meandering

Oxbow Lakes

NE/SD border

Slope

Sediment Load

- fine particles are moved in suspension, never touching the ground (suspended load) - silt & clay giving the water a muddy look

- coarse particles are moved by traction along the stream bed, jumping along (bed load) - move by saltation: short leaps as a strong current picks them up and moves them a short distance. - 7-10% of the total sediment load, on average. - abrasion between particles causing them to wear, smoothing them and forming round pebbles and stones. - also wears away the stream channel along the sides and bottom of the channel.

- dissolved materials are carried along in solution (dissolved load) - invisible chemical ions

QuickTime™ and aSorenson Video decompressorare needed to see this picture.

Mississippi Sediment

Base Level

The lowest elevation (depth) to which a river can erode its bed.

Stream Maturity

Youthful

Mature

Old Age

Old Age River

Flooded River

Levees occur when active deposition takes place along the banks of an older river when it is in a flood. Each time this happens the banks get higher forming a natural levee -- a barrier to future flooding.

Natural Levee

River channel

Levees

Urban Runoff

More pavement = dramatically increased runoff rates

LeveeIf the river doesn’t flood, sediment is deposited on the river bed;causes water level to rise

Concrete PavingSmooth bottom = less friction = fast-moving water = less sediment deposition

Levee Breech

Siltation

Wastewater15,000,000 people. All pavement. 50 inches of precipitation per year. Where does all the water go?

Urban sewer system

Many urban sewer systems are outdated

Wilmington, Delaware

Wilmington

Delaware Streams

Storm Sewer Runoff

Storm Sewer Runoff

Raw untreatedsewage

“IOWA'S BEACHES WILL STAY OPEN THIS YEAR.EVEN IF THEY *ARE* POLLUTED WITH FECAL BACTERIA.THE IOWA DEPARTMENT OF NATURAL RESOURCES SAYS THE BEACHES AT STATE PARKS ARE TOO POPULAR AND VALUABLE TO IOWANS TO CLOSE THEM WHEN THERE ISN'T CLEAR EVIDENCE OF A HEALTH RISK.LAST YEAR, EMERSON BAY IN LAKE OKOBOJI WAS ONE OF SEVERAL BEACHES CLOSED.THE D-N-R SAYS THIS YEAR THE STATE WILL POST WARNING SIGNS INSTEAD.WORKERS WILL BASE THEIR FINDINGS ONLY ON TESTS FOR FECAL COLIFORM BACTERIA.LAST YEAR, THE STATE CONSIDERED THREE DIFFERENT BACTERIAS.THE D-N-R SAYS IT CONSULTED HEALTH OFFICIALS BEFORE DECIDING THAT USING THREE WAS CONFUSING AND CUMBERSOME.”

KMEG News: Storm Lake, IA

Alesund, Norway

Wastewater Treatment

Toxic Runoff

Acid DrainageSummitville, CO:All aquatic life absent for17 miles away from mine.

How bad is it?