Hydrogeology 1

Question 1

Permeability

Answer 1

measure of soil’s ability to permit fluid to flow through its pores or voids

loose soil=easy to flow, high permeability
dense soil = difficult to flow, low permeability

Question 2

Porosity

Answer 2

ratio of volume of voids to total volume
n=Vvoids/Vtotal

dependant on size, shape and packing of grains, lots of empy space=high porosity

Question 3

Why does water flow

Answer 3

flows from high to low energy
energy is dissipated in overcoming the soil resistance, therefore water loses energy as it flows through soil

Question 4

Hydraulic Head

Answer 4

H=pressure head+elevation head

pressure head=height fluid rises
elevation head=elevation of point

Question 5

fluid potential

Answer 5

=gh

defines energy per unit mass of fluid

Question 6

Equipotential line

Answer 6

line along which hydraulic head is constant

Question 7

Streamline

Answer 7

shows direction of groundwater flow
flow direction perpendicular to equipotential lines, from high energy(head) to low

Question 8

Hydraulic Gradient

Answer 8

i=h/L
can go up or downstream depending on different in head
direction of flow perpendicular to gradient and towards smaller head