Water & Carbon - flood hydrographs Flashcards
What are hydrographs?
Flood (storm) hydrographs are graphs that show how a drainage basin responds to a period of rainfall. Hydrologists use them to plan for flood situations and times of drought.
What are cumecs?
Short for cubic metres per second (m³/s), cumecs is a unit of measurement for the flow rate of water, typically used to describe the discharge of a river or stream.
What is the rising limb?
The part of a hydrograph that shows the increase in river discharge following a rainfall event. It represents the period when water is rapidly entering the river system.
What is peak precipitation?
The highest amount of rainfall recorded during a specific period, usually within a storm event. It indicates the maximum intensity of rainfall.
What is lag time?
The time interval between peak precipitation and peak discharge in a river. It represents the delay between the heaviest rainfall and the highest river flow.
How can hydrographs help predict flooding?
They show how river discharge changes over time in response to rainfall. By analysing the shape of hydrographs, we can understand how quickly and significantly a river responds to precipitation, which helps in flood prediction and management.
What is base flow?
The normal, sustained flow of a river or stream, primarily fed by groundwater. It represents the typical flow level in the absence of recent rainfall.
What is storm flow?
The additional flow in a river or stream resulting from a storm event. It includes both surface runoff and any increased flow from tributaries.
What is the falling limb?
The part of a hydrograph that shows the decrease in river discharge after the peak has been reached. It represents the period when the flow is receding.
What is bankfull discharge?
The flow rate at which a river fills its channel to the point of overflowing. It is the maximum discharge that the river channel can hold without flooding. This can vary from river to river depending on multiple different factors.
What is peak discharge?
The maximum flow rate of water passing through a river or stream at a given point and time, usually following a period of heavy rainfall or snowmelt.
