F Topographically driven flow Flashcards
most important driver of flow
elevation head
recharge area
head decreases with depth so drives down flow
discharge area
head increases with depth
drivers of flow
density (saline water or heating at depth)
hinge lines
separates an area of recharge from an area of discharge
where equipotential are mostly vertical
Aspect Ratio
basin depth/ length from GW divide to the lower part of the basin
in anisotropic aquifers
flow lines not perpendicular to equipotential
vertical flow more pronounced
local flow in shallow aquifer
rapid flow
short residence time
favours reactions limited by fluid flux (carbonate dissolution)
regional flow in deep aquifers
slow flow
long residence time
elevated temp as at depth
favours kinetically controlled reactions as warmer
Stagnation point
hydraulic potential higher surrounding point
between local and regional systems
contaminant only moves by diffusion
Hyporheic zone what is it
interchange between stream and ground water
hyporheic zone provides
shelter for organisms, plants and fish
reduction in pollutants in the stream
