the point which defines the watershed, the location where the watershed all flows to.
smaller sub-watersheds are found within larger networks of watersheds
Subdivisions of a large watershed to create land unitswith comparable characteristics.This simplifies computer modelingand allows us to identify flowcharacteristics at multiple pointswithin a watershed.
On a topographic map water flows are shown:
as perpendicular to contour lines
On a topographic map in steeper areas contour lines are depicted:
On a topographic map in flatter areas contour lines are depicted:
On a topographic map a ridge top or mountain top is depicted by:
closed contour line
On a topographic map a valley bottom is depicted by:
“v” shape pointing uphill in the contour lines
On a topographic map a ridge is depicted by:
“v” shape pointing downhill
Why is the drainage area so important?
It reflects the volume of water that is generated during rainfall. It is common in hydrologic design to assume a constant depth of rainfall throughout the watershed.
Under this assumption the volume of rainwater available for runoff would be the product of the rainfall depth and drainage area.
What are the three linear measurements used for channel length?
L-The distance measured along the main channel from the watershed outlet to the basin divide.Lc – The distance from watershed outlet to the end of the channel as indicated on the map.L10-85 – Distance between two points located at 10 and 85% of the distance from the outlet.
Location of the point within the drainage basin that represents the weighted center of the basin.