GW-SW interactions

Question 1

Hydrogeological unit

Answer 1

comprises one or more geological units with almost similar hydrogeological properties (ex hydraulic conductivity)

Question 2

Aquifer

Answer 2

permeable hydrogeological unit that stores large amount of water and permits large amount of water move throguh it under field conditions

ex. sands, gravels from aluvial, glacial or deltaic origins
sandstone, karst limestone, fractured basalt

Question 3

Aquitard

Answer 3

less permeable hydrogeological unit that stores water but is incapable of transmitting significant quantities of water

ex. silt and clay
shales and crystaline rocks

Question 4

unconfined vs confined aquifer

Answer 4

unconfined = an aquifer in which the water table forms the upper boundary

confined = aquifer confined between aquitard layers (ex clay), or aquifer that is overlain by relatively impermeable unit such that the aquifer could be under pressure and the water level rises above the confined unit

Question 5

Groundwater Table/Phreatic Surface

Answer 5

surface along which pressure head =0

Question 6

Baseflow

Answer 6

the portion of the stream(or river) that is sustained between precipitation events, fed to stream from groundwater storage

Question 7

Describe ground-water stream interactions

Answer 7

gaining streams
-water table level with stream; ground-water flows into stream
-contour lines point upstream

losing stream
-water table below river level; surface water leaches into ground-water
-contour lines point in downstream direction

Question 8

Describe disconnected streams

Answer 8

streams are separated from groundwater by an unsaturated zone

Question 9

describe bank storage

Answer 9

if stream levels rise higher than adjacent ground-water levels, stream moves into the streambanks as bank storage

Question 10

Describe ground-water stream water withdrawal interactions

Answer 10

If you draw water near stream, it will pull water groundwater away from stream
if you increase the discharge of the withdrawal it will pull surface water into the ground and through your withdrawal(dry up lakes/rivers)

Question 11

Describe ground-water spring interactions

Answer 11

when perched aquifer intersects with land surface it causes springs
-occurs when water table intersects with earths surface

Question 12

Describe ground-water lake interactions

Answer 12

lakes can have ground-water inflow or outflow throughout their entire bed, or have both inflow and outflow at different localitites

Question 13

Describe ground-water wetland interactions

Answer 13

can occur at slopes (unlike lakes/rivers)
-at seepage face or break in slope