1.4 The human impact Flashcards
Abstraction
Amount taking out
Bankfull stage
Condition in which a river’s channel fills completely that any increase in discharge will cause water to overflow the bank
Channel
Passageway in which a river flows
Channelisation
Modifications to the river channels. (straightening, deepening, widening, clearing or lining.
Discharge
Quantity of water that passes a given point on the bank of a river.
Drainage basin
Total area that contributes water to a river.
Flash flood
Flood where lag time is quite short
Flood
Discharge great enough to cause a body of water to overflow its channel.
Flood-Frequency curve
How often and how large floods are in an specific area
Floodplain
Part of any stream valley that is inundated during floods
Hazard assessment
Process of determining when and where hazards have occurred in the past. The frequency as well as events that could happen now.
Natural hazards
Range of natural circumstances, materials and processes that are hazardous to humans.
Risk assesment
Establishing the probability that a hazardous event of a particular magnitude will occur within a given period.
Flood abatement
Decreasing the amount of runoff