1. GROUNDWATER

2. GROUNDWATER

3. GROUNDWATER
Aquifer
“Geologic unit that can store and transmit enough water to be a significant water resource”
1. Large volume (in relation to the amounts being removed annually)
2. Moderately high porosity
3. Facilitate easy movement of water toward a well
aquiclude

4. GROUNDWATER
Confined versus unconfined

5. GROUNDWATER

6. GROUNDWATER

7. GROUNDWATER
Elevation energy and pressure energy

8. GROUNDWATER
Elevation energy and pressure energy

9. GROUNDWATER Potentiometric surface Equipotential lines
Potentiometric contours

10. GROUNDWATER

11. GROUNDWATER

12. GROUNDWATER

14. GROUNDWATER
Vx = Q/A
Water potential (hydraulic) gradient:
Q = h/d

15. GROUNDWATER Q = A h/d Q = K A (h/d) Hydraulic conductivity (K)
Q = K A (h/d)
Hydraulic conductivity (K)
“Permeability”
T = Kb
where b = aquifer thickness  

16. GROUNDWATER

17. GROUNDWATER

18. GROUNDWATER

19. GROUNDWATER Storage properties of aquifers
In GW flow, S = 1 and  volume stored/unit volume = 

20. GROUNDWATER
The volume of water a unit volume of aquifer releases in response to Dh =
Specific storage, Ss
Volume water released [L3]
Ss =
Volume of aquifer [L3] x Dh [L]
Storage coefficient or storativity, S
S =
Surface area of aquifer [L2] x Dh [L]

21. GROUNDWATER
 S and Ss are related as
S = bSs

22. GROUNDWATER Unconfined aquifer: Specific yield (Sy) = sy
Specific yield (Sy) = sy
= volume of stored GW released per unit surface area per unit decline of
 S = sy
 sy = bSs
and Ss = sy b

23. GROUNDWATER Fc
 = Sy + Sr

24. GROUNDWATER

25. GROUNDWATER

26. GROUNDWATER

27. GROUNDWATER

28. GROUNDWATER

29. GROUNDWATER