2Watershed Watershed: The land drained by a river or stream and all of its tributaries.Also known as aDrainage Basin.Watershed boundaries,or divides, are typicallydefined by the highestelevation that drainsa stream.
3Watersheds The rate at which water travels through a watershed is determinedby factors such as:its size (total surface area)topography (flat or steep)amount and type of vegetationhuman developmentThe total amount of water that collects ina river that drains the watershed is calledits Discharge.Discharge is measured in meters3/second.Total Discharge
4Drainage Patterns Drainage patterns depend mostly on: (1) topography; and (2)the type ofrock over whichstreams flow.
5Stream Order Stream Order: a system of classifying streams and rivers based on theirrelationship or position in the drainagenetwork.Streams at the beginning of the system are calledfirst-order streams. First order streams receive water directly from a source such as a spring, lake,melting snow, etc.When two first order streams join, the resulting streamis now classified as a second-order stream.
6Stream Order Note: the stream order will increase only when two like streamsjoin.
7Slide 1: Stream Order Identify the proper stream order for each of the following locations.1324
8Slide #2 Lackawanna River Watershed Name the mountains that act as the boundary/divide onthe eastern portion of theLackawanna River watershed.How many countiescomprise the LackawannaRiver watershed?The Lackawanna Rivereventually flows into whichlarger river?Which type of drainagepattern is dominant in theLackawanna River watershed?
9Slide 3: Stream Gradient 123Place in order from fastest stream velocity to slowest the three locationsin the above diagram.Which number would best illustrate a youthful stream?Which number would best illustrate a mature stream?Which number would carry the largest sediments (pebbles, cobbles, boulders)?Which location is most likely to have extensive meandering?Small sediments like sand and silt will be most likely found at which location?
10Slide 4: Mississippi Watershed Name the mountainsthat cause the divideon the western boundaryof the watershed.2. Name the mountainson the eastern boundary
11Slide 5: PA’s Major Watersheds 1. Name the bodies of water that each watershed eventually drains into.2. Which watershed includes theLackawanna River watershed?
12Drainage Patterns Slide #6 #BSlide #6Identify the type ofdrainage pattern foreach example and;Discuss how,geologically, eachpattern forms.#C#D
13Watershed Questions1. Describe the relationship between stream order and the size of a watershed. 2. Describe how humans can affect a watershed. Give specific examples. 3. Describe how increased human development will affect how surface water travels through a watershed. 4. Compare a saturated and unsaturated geosphere and how each will influence the rate of surface water flow and discharge of a watershed.
14Watershed DynamicsAll of the following watersheds are equal in surface area and receive equal rainfall. Compare and contrast each of the following watersheds: Discuss specifically, a. the rate of surface water flow through each watersheds (faster or slower) b. possible disruptions to flow. Give specifics! c. final discharge (more or less) 5. Flat (slope) terrain vs. steep (slope) terrain 6. Agricultural vs. forested land 7. Rural development vs. urban development