river regimes Flashcards
what is storm hydrograph
graph of river discharge during storm event
outline a storm hydropgraph
baseflow - fed by throughflow
fast moving water from storm
rising limb
peak discharge
lag time
receding limb
return to base flow
physical factors impacting drainage basins
circular shape - flashy as tributaries equidistant
steep sides - flashy as overland flow
high drainage density
already saturated - cant infiltrate
impermeable rock
thick vegetation - interception and takes up and is evap/transpired
intensity rain
size basin
human factors impact drainage basin
deforestation
afforestation
agriculture
urbanisation
how does deforestation impact DB
reduce interception
rapid overland flow
flashy
expose soil
erosion
sedimentation of channel
reduces bankfull capacity
flooding
how does afforestation impact DB
inc interception
subdued
how does agriculture impact DB
ploughing
break up topsoil
more infiltrate
subdued
plough wet
make impermeable
dec percolation
overland flow
flashy
crops
interception
inc infiltration
subdued
animals
compact soil
impermeable
flashy
how does urbanisation impact DB
more impermeable surfaces
flashy
drains
fast to enter river
flood
water abstraction
lowers base flow
more water required before bankfull
