32. Boundary condition is important when the
effect of transient stresses reach the boundary
1.Physical boundaries (impermeable rock
formation)
2.Hydraulic boundary ( groundwater divide ,
partly aquifer penetrating water bodies and
streamlines )
3.No flow boundary (fault zones and salt water
interface)
33. Formula:
q = K *p* h /f
,
• where: q= = total
discharge per unit
width of aquifer (L3/T)
• K = hydraulic
conductivity
• p = number of flow
tubes
• h = total head drop
• f = number of squares,
covering length of flow
34. Equations of groundwater flow
A) Steady flow in a confined aquifer
- Flow implies that the aquifer has a gradient (Remember: water
flows downhill)
35.
36. B) Steady flow in an unconfined aquifer:
Aquifer isn't always fully saturated.
Gradient is not constant now.
Gradient increases in the direction of flow .
37. 2 problems:
- Equation for this sloping surface is much more complicated
- Also: recharge from the surface affects the gradient
- The solution: make some assumptions about boundary
conditions, calculate discharge through a section of the aquifer: