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Surface Water. Where Does the Water Go?. Precipitation. Percolates into Soil/rock. Runoff. ____________. _____________. Lakes, ponds, streams Ocean, wetlands. 52%. 8%. Surface Water. 38%. 1%. 1%. River Systems. __________. Collects. ________: Tiny water channels. Merge.
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Where Does the Water Go? Precipitation Percolates into Soil/rock Runoff ____________ _____________ Lakes, ponds, streams Ocean, wetlands
52% 8% Surface Water 38% 1% 1%
River Systems __________ Collects ________: Tiny water channels Merge ________________ Merge _________ Empty _________
River System • _________________: Network of rivers and streams draining a river basin • _____________: Feeder streams • Major River Systems • _______________ • ________________ • ________________ • _________________
Susquehanna (Main) Susquehanna (West) Delaware Schuylkill Juniata Lehigh Ohio Allegheny Monongahela Lackawaxen Lackawanna Youghiogheny Shenango Clarion Pennsylvania’s Major Rivers
Major Drainage Patterns • Drainage patterns depend on: • ___________________: Physical characteristics of the land. • Rocks over which the water travels
Types of Drainage Patterns • ______________: Resembles a mature tree • Most river systems in PA • Main river forms trunk • Uniform bedrock • Function of the slope of the land
Types of Drainage Patterns • ____________: “Spokes on a wheel” • Streams flow from a high central area • __________ • __________
Types of Drainage Patterns • ______________: • Rock broken by a series of faults and fractures • “Bends” in stream form right angles
Types of Drainage Patterns • _____________: • Type of rectangular • Tributary streams are parallel to each other • Rock alternate between hard and soft
Types of Drainage Patterns • ______________: • Large body of water (lake) at the center • “Feeder Streams” empty into the lake
Watersheds (Drainage Basin) • Watersheds: The area of land that is drained by a river. • Surrounded by topographic highs called Divides. • Divide: Any ridge between two streams along which precipitation runs off. • PA has 104 watersheds
Watersheds (Drainage Basin) • 6 Major PA Watersheds • _________________ Basin • ______________ River Basin • ___________________ Basin • ____________________ Basin • _____________________ Basin • _____________________ Basin
Identifying the Boundaries of a Watershed (Delineation) • Step #1: Identify the stream to be delineated. • Step #2: Using a pencil and ruler, draw a series of lines (1-2 cm in length) perpendicular to the stream, spaced 1 cm apart. • Step #3: At the headwaters, draw several lines radiating outward. • Step #4: Follow the perpendicular lines drawn and find the highest elevation that is closest to the steam.
Identifying the Boundaries of a Watershed (Delineation) • Step #5: Place an “X” at the highest elevation point. • Step #6: Repeat steps #4 & #5 for all of the perpendicular lines drawn. • Step #7: Connect the “X’s” to outline the boundary of the watershed.