WATERSHEDS / DRAINAGE BASINS

1
WATERSHEDS / DRAINAGE BASINS
Def The area of land drained by any one stream
REMEMBER a stream is running water thats
confined to a channel---this channel can be any
size
2
QWhere does water go once it hits the surface of
the earth? A Some gets absorbed into the ground
(infiltration) some flows along the surface
(runoff)
3
Water always flows from HIGH elevation to LOW
elevation.
Along the way, this water combines with other
water, so the size of the stream gets bigger and
bigger.
4
The rivers of New York State obtain their water
from very distinct regions. The state is divided
into the following DRAINAGE BASINS (WATERSHEDS)
These watershed regions are pretty small because
the streams they feed into are pretty small
In what drainage basin is Hyde Park?
5
Watersheds Continental Divide and Appalachian
Mountains
Water goes from high sea level to low sea level
6
The UNITED STATES is split into two LARGE
drainage basins.
7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
Drainage Patterns of Watersheds

• Dendritic
• Radial
• Rectangular
• Trellis

11
(No Transcript)
12
Dendritic Drainage Patterns

• Dendritic drainage pattern is the most common
  form and looks like the branching pattern of tree
  roots.
• It develops in regions underlain by homogeneous
  material.
• The subsurface bedrock all has a similar
  resistance to weathering so there is not a path
  of least resistance, the resistance is equal in
  every direction the tributaries take.
• Tributaries joining larger streams at acute angle
  (less than 90 degrees).

13
Drainage Patterns of Watersheds

• Dendritic
• Radial
• Rectangular
• Trellis

14
(No Transcript)
15
Radial Drainage Patterns

• radial drainage pattern develops around a central
  elevated point.
• This pattern is common to cone shaped features
  such as volcanoes.
• The tributary streams originate at the highest
  points toward the top of the volcano or cone.

16
Drainage Patterns of Watersheds

• Dendritic
• Radial
• Rectangular
• Trellis

17
(No Transcript)
18
Rectangular Drainage Patterns

• rectangular drainage pattern is found in regions
  that have undergone faulting.
• Streams follow the path of least resistance and
  thus are concentrated in places where exposed
  rock is the weakest.
• Movement of the surface due to faulting off-sets
  the direction of the stream.
• As a result, the tributary streams make sharp
  bends and enter the main stream at high angles.

19
Drainage Patterns of Watersheds

• Dendritic
• Radial
• Rectangular
• Trellis

20
(No Transcript)
21
Trellis Drainage Patterns

• Trellis drainage patterns look similar to their
  namesake, the common garden trellis.
• Trellis drainage develops in folded topography
  like that found in the Appalachian Mountains of
  North America.
• Down-turned folds called synclines form valleys
  in which the main channel of the stream flows.
• Short tributary streams enter the main channel at
  sharp angles, as the tributaries run down sides
  of parallel ridges called anticlines.
• Tributaries join the main stream at nearly right
  angles.