Running on water Water can’t run it doesn’t have legs

Water TriCycle  The water cycle is the movement of water among land, oceans and atmosphere. The cycle is never-ending The cycle is never-ending  The energy of the water cycle comes from the sun  The amount of water the earth has now has been the same since the creation of the earth

Riding my water triCycle  The water cycle consists of… Water evaporating into the atmosphere Water evaporating into the atmosphere Water condensing and falling to the ground (precipitation) Water condensing and falling to the ground (precipitation) Water runoff & Infiltration Water runoff & Infiltration Infiltration is the movement of surface water through rock and soilInfiltration is the movement of surface water through rock and soil These parts do NOT always happen in this order These parts do NOT always happen in this order

Water Balance  The water cycle is what we call Balanced This means that the TOTAL precipitation is equal to the TOTAL amount of water evaporated This means that the TOTAL precipitation is equal to the TOTAL amount of water evaporated This is because water is not lostThis is because water is not lost Localized places may not have balanced water cycles Localized places may not have balanced water cycles Continents tend to have more precipitation then evaporation and oceans tend to have more evaporation then precipitationContinents tend to have more precipitation then evaporation and oceans tend to have more evaporation then precipitation

Go with the stream-flow  Gravity is the leading reason streams flow Because of gravity water wants to flow to the lowest point Because of gravity water wants to flow to the lowest point Streams flow down hillStreams flow down hill  When a stream is flowing it erodes the land and carries the material downstream The ability of a stream to erode and transport materials depends largely on its velocity The ability of a stream to erode and transport materials depends largely on its velocity Faster streams can carry more and heavier materialsFaster streams can carry more and heavier materials

Streams and velocity  A stream flowing in a strait line has it’s fastest moving water in the middle of the stream  As a stream turns it’s fastest moving water is further to the outside Think of making a turn in a car; you go to the outside of the turn Think of making a turn in a car; you go to the outside of the turn

Stream flow characteristics  Gradient: is the slope or steepness of a stream channel The higher the gradient of a stream the faster it will flow The higher the gradient of a stream the faster it will flow  The Mississippi river at many points has a gradient of 10cm drop for every 1 km it goes downstream Many mountain streams can be 400x’s more Many mountain streams can be 400x’s more

Channel characteristics  The channel is land where a river or stream flows through If the stream has an irregular shape and consists of large boulders at the bottom it will slow the overall speed of the stream If the stream has an irregular shape and consists of large boulders at the bottom it will slow the overall speed of the stream The reason it slows is due to frictionThe reason it slows is due to friction Smaller steeper channels will produce more friction between the water and the surface of the channel Smaller steeper channels will produce more friction between the water and the surface of the channel Large wide channels will produce the highest speed Large wide channels will produce the highest speed

Discharge  Discharge: volume of water that passes by a certain point in a given amount of time Speed and size of a steam will dictate the total amount of discharge of a river/stream Speed and size of a steam will dictate the total amount of discharge of a river/stream The discharge of steams and rivers change based on rainfall amounts and possible snowmeltsThe discharge of steams and rivers change based on rainfall amounts and possible snowmelts Urban areas can increase the discharge of streams Urban areas can increase the discharge of streams This happens by decreasing the amount of water absorbed by soilsThis happens by decreasing the amount of water absorbed by soils

Largest Rivers by discharge RankRiverCountry average discharge (m^3/s) 1AmazonBrazil212,400 2CongoZaire39,650 3YangtzeChina21,800 4BrahmaputraBangladesh19,800 5GangesIndia18,700 6YeniseiRussia17,400 7MississippiUnited States17,300 8OrinocoVenezuela17,000 9LenaRussia15,500 10ParanaArgentina14,900

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A river’s life  One useful way to study a steam is to look at It’s profile A stream’s gradient usually decreases as it goes downstream A stream’s gradient usually decreases as it goes downstream But it’s discharge increases But it’s discharge increases Discharge increases because tributary’s flow into the main streamDischarge increases because tributary’s flow into the main stream Tributaries are streams that empty into another larger stream or riverTributaries are streams that empty into another larger stream or river As a stream goes downhill it also increases in it’s velocity As a stream goes downhill it also increases in it’s velocity This may go against what you think with mountain streamsThis may go against what you think with mountain streams

Base level  Streams do have a level at which they can’t erode any further This level is called the base level This level is called the base level When a stream gets close to it’s base level it will begin to meander When a stream gets close to it’s base level it will begin to meander  Meanders are large bends in the stream They are most common when the gradient is low They are most common when the gradient is low