FRESHWATER COULTER

RIVER SYSTEMS: TRIBUTARIES

• RIVERS OFTEN BEGIN IN THE MOUNTAINS, WHERE RUNOFFS FROM MELTING SNOW FORMS SMALL STREAMS.

• AS YOU FOLLOW A SINGLE STREAM YOU WILL NOTICE THAT IT JOINS ANOTHER.

• THESE STREAMS WILL EVENTUALLY FLOW INTO A SMALL RIVER WHICH WILL THEN JOIN A LARGE RIVER.

• THESE STREAMS AND SMALLER RIVERS ARE CALLED TRIBUTARIES.

• A RIVER AND ALL ITS TRIBUTARIES TOGETHER MAKE UP A RIVER SYSTEM.

RIVER SYSTEMS: WATERSHED

• THE LAND AREA THAT SUPPLIES WATER TO A RIVER SYSTEM IS CALLED A WATERSHED.

• WATERSHEDS ARE SOMETIMES KNOWN AS DRAINAGE BASINS.

• MISSOURI AND OHIO RIVERS ARE LARGE YET FLOW INTO THE MISSISSIPPI RIVER. SO LARGE RIVERS JOIN ANOTHER RIVER SYSTEM.

• THE AREAS THEY DRAIN FROM BECOME PART OF THE LARGEST RIVER’S WATERSHED.

RIVER SYSTEMS: DIVIDES

• ONE WATERSHED IS SEPARATED FROM ANOTHER BY A RIDGE OF LAND CALLED A DIVIDE.

• STREAMS ON EACH SIDE OF THE DIVIDE FLOW IN DIFFERENT DIRECTIONS.

• CONTINENTAL DIVIDE: LONGEST DIVIDE IN NORTH AMERICA FOLLOWS THE ROCKY MOUNTAINS.

PONDS

• IN GENERAL PONDS ARE SMALLER AND SHALLOWER THEN LAKES. SUNLIGHT USUALLY REACHES TO THE BOTTOMS OF ALL PARTS OF A POND.

• BODIES OF FRESH WATER.

• CONTAIN STILL WATER.

• HOW PONDS FORM:

• PONDS FORM WHEN WATER COLLECTS IN HOLLOW LOW-LYING AREAS OF LAND.

• SOME PONDS ARE SUPPLIED BY RAINFALL, MELTING SNOW AND ICE, RUNOFFS, RIVERS, OR GROUNDWATER.

• NOT ALL PONDS EXIST YEAR ROUND; SOME PONDS APPEAR IN SPRING WHEN RUNOFF AND MELTING SNOW COLLECT IN LOW AREAS, THEN BY MIDSUMMER DRY UP DUE TO EVAPORATION.

LAKES

• LAKES ARE GENERALLY DEEPER AND BIGGER THAN PONDS. IN ADDITION, SUNLIGHT DOES NOT REACH THE BOTTOM IN A DEEP LAKE, AS IT DOES IN A POND.

• NO PLANTS AND FEW ORGANISMS LIVE IN THE LAKES DEPTHS.

• BOTTOM OF A LAKE CONSISTS OF SAND, PEBBLES, OR ROCK, WHEREAS THE BOTTOM OF A POND IS USUALLY COVERED WITH MUD OR ALGAE.

HOW LAKES FORM

• SOME, SUCH AS THE GREAT LAKES, FORMED IN DEPRESSIONS CREATED BY ICE SHEETS THAT MELTED AT THE END OF THE ICE AGE.

• OTHERS WERE CREATED BY MOVEMENT OF EARTH’S CRUST.

• SUCH MOVEMENTS FORMED THE DEEP VALLEYS IN CENTRAL AFRICA THAT LIE BELOW LAKE TANGANYIKA AND LAKE VICTORIA.

HOW LAKES FORM CONT.

• OTHER LAKES ARE THE RESULT OF VOLCANOES.

• ERUPTIONS CAN CAUSE A FLOW OF LAVA OR MUD THAT BLOCKS A RIVER AND FORMS A LAKE.

• SEA OF GALILEE WAS FORMED BY LAVA BLOCKING JORDAN VALLEY

• SOME FORM IN THE EMPTY CRATERS OF LAKES.

• LAKES CAN ALSO BE FORMED BY BUILDING A DAM (HELLO LAKE MEAD)

WETLAND

• WETLAND IS A LAND AREA THAT IS COVERED WITH WATER DURING PART OR ALL OF THE YEAR.

• HELP CONTROL FLOODS AND PROVIDE HABITATS.

• TYPES OF WETLANDS: THE THREE COMMON TYPES OF FRESHWATER WETLANDS ARE MARSHES, SWAMPS, AND BOGS.

MARSHES

• MARSHES ARE USUALLY GRASSY AREAS COVERED BY SHALLOW WATER OR STREAMS.

SWAMPS

• LOOK MORE LIKE FLOODED FORESTS, WITH TREES AND SHRUBS SPROUTING FROM THE WATER.

• MANY ARE LOCATED IN WARM, HUMID CLIMATES, WHERE TREES GROW QUICKLY.

BOGS

• ARE MORE COMMON IN COOLER NORTHERN AREAS.

• THEY OFTEN FORM IN DEPRESSIONS LEFT BY MELTING ICE SHEETS THOUSANDS OF YEARS AGO.

• WATER IN BOGS TENDS TO BE ACIDIC, AND MOSSES THRIVE IN THESE CONDITIONS.

COASTAL WETLANDS

• INCLUDE SALT MARSHES AND MANGROVE FORESTS.

Salt marsh Mangrove forest

PROTECT THE WETLANDS!!

• BECAUSE OF THEIR SHELTERED WATERS AND RICH SUPPLY OF NUTRIENTS, WETLANDS PROVIDE HABITATS FOR MANY LIVING THINGS.

• WETLANDS HELP POLLUTION CONTROL.

• WETLANDS ACT AS NATURAL WATER FILTERS. THEY ALSO HELP CONTROL FLOODS BY ABSORBING EXTRA RUNOFF FROM HEAVY RAINS.

• WETLANDS ARE LIKE GIANT SPONGES, STORING WATER UNTIL IT GRADUALLY DRAINS OR EVAPORATES.