Hydrology & Fluvial Geomorphology Flashcards
(23 cards)
Define drainage basin
Catchment area for water whick drains into a river and its tributaries
What is precipitation?
Rainfall will follow the routes within the drainage basin system
Equation for water balance?
P=Q+E+/-S
Discharge?
Amount of volume of water flowing past a particular point at a given time
Discharge measured in?
Cumec - cubic meter per seconds
Lag time?
Time diffrent between maximum precipitation and peak discharge
What is flood?
A discharge great enough to cause a body if water to overflow its channel and submerge the surrounding land
Primary effects of flood?
Loss of life, houses damaged, crop damage, roads and railways damaged
Secondary effects of flood?
Homeless, food supply problems, diseases spread, polluted water and reconstruction cost
Name flood protection methods
Building dams, levees, flood wall, canalisation, and afforestation
Name the 3 types of flows
Laminar, turbulent and helicodial flow
What are the four types of erosion processes
Hydraulic action, corrasion, solution and attrition
What are the four types of transport processes
Traction, saltation, suspension and solution
Deposition?
Where material carried by the river is dropped
Why does deposition occur?
Because there is no longer sufficient energy to transport material
What are rapids?
Series of very short and fast falls
Levees?
A raised river bank
Hjulstrom curve?
Shows the relationship between velocity and particle size. It shows velocities for erosion, deposition and the area where transportation will continue to occur
Why does clay require high velocity eventhough clay is small
Have the tendancy to stick together which is very hard to seperate
What is a riffle?
Shallow parts of a river where water flows more turbeluntly over depostis of coarse materials
Where does a riffle occur?
Middle course
What are pools?
Deeper sections in a river where water flows less turbulently over deposits of fine materials
Where do pools occur
Middle course
