leanne, sewater intrusion lecture 2 Flashcards
typical feature of costal aquifers
-fluctuating sea levels result in alternative continental and marine sediments
thicker seaward
aquifer-gravels and sands
aquitards, marine silt and clay
recharge from slope
discharge mechanisms for the aquifers
ET
sepage to springs, and sea floor
mixing with seawater
flow through layers
whats it called with the two layers of fresh and salt and whats the definition
halocline, vertical zone of oceanic water column in which salnity changes rapidly with depth
what are the three scales
nearshore scale
embayment scale
shelf scale
equation for equivalent fresh water pressure head
hf=hs*(salty density/fresh desntiy)
draw the two circulating sea plumes for an unconfined aquifer
ok
list the 5 sewater intrusion mechanisms
pumping decreased recharge sea level rise overtopping land use change
differemt ways of measuring sewater intrusion 3
temporal and spatial trends in salinity and hydraulic heads -piezometers
geophysical mapping-resistivity, and electromagnetic methods
origns and transport- tracers and isotopes
simple methods for modelling sewater intrusion
sharp interface
steady state
ghyben herzberg
complex method
transient , sharp interface
dispersion and flow
prove the relationship between Z and H
ok
three things change toe distance
recharge increase, toe distance idecreases
sea level increase, toe distance increases
gw discharge increase, toe distance increases
four main points to SWI for australia
aquifers no longer flowing to sea
sea equiv heads larger
non steady state
active intrusion
draw, active ,active passive, and passive
ok
ways to manage intrusion (5)
regulate wells pump from shallower barriers extract seawater sand motor
