CHAPTER 13 SURFACE WATER13.1 STREAMS AND RIVERS

WATER CYCLE

RIVER SYSTEMSA RIVER AND ALL IT’S

TRIBUTARIESTRIBUTARIES –

SMALLER STREAMS THAT RUN INTO THE MAIN RIVER – AND CARRY ERODED ROCK – SEDIMENTFOR

RS ACCOUNT FOR MOST EROSION ON EARTH’S SURFACE

DRAINAGE BASIN / WATERSHEDS

ALL THE LAND THAT DRAINS INTO THE RIVER

SEPERATED BY DIVIDES

CONTINENTAL DIVIDERUNS THROUGH

ROCKY MOUNTAINS

RAIN FALLING TO THE WEST FLOWS TO

PACIFICEAST FLOWS TO

ATLANTIC

MISSISSIPPI RIVER WATERSHEDLARGEST SINGLE

DRAINAGE BASIN IN U.S. – 4.76 MILLION km2

WEST DIVIDE= CONTINENTAL DIVIDE

EAST DIVIDE = APPALACHAIN MTNS

MISSISSIPPI RIVER WATERSHEDDUBOIS

PENNSYLVANIA WATERSHEDS –WHERE DOES OUR WATER GO?

PA DRAINAGE BASINSUSQUEHANNA VALLEY WATERSHED

CHESAPEAKE BAY WATERSHED

CHARACTERISTICS OF STREAMS AND RIVERS

ABILITY OF STREAMS AND RIVERS TO ERODE, TRANSPORT AND DEPOSIT SEDIMENT IS AFFECTED BY MANY FACTORSFACTORS INCLUDE:

VELOCITY OF WATER GRADIENT OF STREAM DISCHARGE SHAPE OF CHANNEL

STREAM VELOCITYDISTANCE WATER

TRAVELS IN GIVEN AMOUNT OF TIME

FACTORS AFFECTING SPEED:1. STEEPNESS OF

SLOPE2. AMOUNT OF

WATER3. THE SHAPE OF

STREAM

GRADIENT – STEEPNESS OF SLOPEVARIES

AT SOURCE – LARGE

AT SEA LEVEL - SMALLLARGE

SOURCE

SMALLGentle

DISCHARGE NOT CONSTANTGENERALLY INCREASE

DOWNSTREAM TRIBUTARIES ADD

MORE WATERDESERTS DECREASE

YEARLY VARIATIONSPRING MELTS –

VELOCITY = MAYBE FLOODING = DISCHARGE

CHANNELTHE PATH

THROUGH WHICH WATER FLOWS

SIZE SHAPE AFFECT VELOCITY

SLOW

FAST

MORE SURFACE AREA

LESS SA

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