Flood Hydrographs Flashcards
What is a flood hydrograph
Used to represent rainfall for the drainage basin of a river and the discharge of the same river on a graph
Who’s is the discharge
The volume of water passing through a cross-sectional point of the river at any one point in time
Measured in cubic metres per second
Who’s is the rising limb
The line on the graph that represents the discharge increasing
What is the falling limb
The line on the graph that represents the discharge decreasing
What is the Lag time
The time between peak rainfall and peak discharge
What is the base flow
The level of groundwater flow
What is storm flow
Compromised of overland flow
What is bank full discharge
The maximum capacity of the river
If discharge exceeds this then the river will bursts its banks and be in flood
Flashy Hydrograph
Short lag time and high peak discharge, most likely to occur during a storm event
Steep rising and falling limb
Higher flood risk
Subduded hydrograph
Long lag time and low peak discharge
Gradually rising and falling limb
Lower flood risk
