A hydrograph is a graph showing the rate of flow (discharge) versus time past a specific point in a river, or other channel or conduit carrying flow. The rate of flow is typically expressed in cubic meters or cubic feet per second (cms or cfs)

1. Hydrograph

2. Hydrograph
•A hydrograph is a graph showing the rate of
flow (discharge) versus time past a specific
point in a river, or other channel or conduit
carrying flow. The rate of flow is typically
expressed in cubic meters or cubic feet per
second (cms or cfs)

4. • These hydrographs are an easy and quick
way to assess the hydrologic conditions in
your HAS
•rivers are whether rising, falling or
remaining steady; whether flows are high,
low, or near base flow; if the rivers have
crested, or are near crest, etc..

5. Unit hydrograph
•A Unit Hydrograph is by definition, a
hydrograph having a volume of 1 inch
of runoff which is associated with a
precipitation event of specified
duration and areal pattern (uniforam
over the basin).

6. Types
•Storm hydrographs
• Flood hydrographs
•Annual hydrographs

7. Storm hydrographs
• graphs that show how a drainage basin responds to a period of
rainfall.

8. Flood hydrographs
• visual representation of the variation in the
stream or river depth over time.
• Flooding normally occurs when the depth of
the stream exceeds the depth from the
stream bank to the stream bottom.

10. Annual hydrograph
•shows the average daily flow of a river over
the course of one year rather than a period
of hours
•It Is affected by a number of controls that
are various importance depending on the
drainage basin concerned or the time of
the year

11. Uses
• Storm hydrograph are useful in planning for flood situations and
times of drought as they show the discharge (amount of water
reaching channel via surface run-off
• Flood hydrograph is used to measure the ‘characteristics’ of a river
the gradient, the velocity etc. The flood hydrograph is basically a dual
plot of river discharge and rainfall.