Lesson 8 - Hydrograph Analysis Flashcards Preview

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Flashcards in Lesson 8 - Hydrograph Analysis Deck (15)
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1
Q

It is a continuous plot of instantaneous discharge vs time

A

Hydrograph

2
Q

Detailed analysis of hydrographs is usually important in flood damage mitigation, flood forecasting or establishing design flows for structures that convey floodwaters.

A

Hydrograph Analysis

3
Q

Components of Runoff:

A
  • Overland flow or Surface Runoff
  • Interflow or Subsurface Storm Flow
  • Groundwater Flow or Base Flow
4
Q

The water that travels over the ground surface to a channel.

A

Overland Flow or Surface Runoff

5
Q

The precipitation that infiltrates the soil surface and move laterally though the upper soil layers until it enters a stream channel

A

Interflow or Subsurface Storm Flow

6
Q

The portion of precipitation that percolates downward until it reaches the water table.

A

Groundwater flow or Base Flow

7
Q

It has been customary to consider the total flow to be divided into two parts:

A

Direct runoff and the base flow

8
Q

Presumed to consist of surface runoff and substantial portion of the interflow

A

Direct runoff

9
Q

Considered to be largely groundwater

A

Base Flow

10
Q

The time from the center of mass of the rainfall excess to the peak of the hydrograph

A

Lag Time

11
Q

The time from the start of rainfall excess to the peak of the hydrograph

A

Time of rise or peak

12
Q

One estimate is the time from the end of the rainfall excess to the inflection point of the hydrograph

A

Time of Concetration

13
Q

The total duration of the Direct runoff hydrograph

A

Time base

14
Q

A typical hydrograph resulting from an isolated period of rainfall consists of a rising limb, crest segment and falling limb and recession

A

Recession and Base flow separation

15
Q

Baseflow Separation Techniques

A
  • Straight-line method
  • Fixed Base Method
  • Variable Slope Method