Hydrogeology GEOL 611


Darcy's law

(Fig)(Fig 6.1)(Fig 6.2)(Fig. 6.3)(Fig 6.4)(Fig 6.5)(Fig)(Fig 6.6)(Fig 6.7)(Fig 6.8)(Fig 6.9)(Fig 6.10)(Fig 6.11)

Introduction

Conceptual model of groundwater flow

  • the flow of water through a porous medium (Fig 6.1)
  • water flows tortuous paths
  • geometry of channels is very complex
  • frictionles flow is totally meaningless!
  • conceptual model of flow through a porous medium is flow through a bundle of very small (capillary) tubes of different diameters (Fig 6.2)
  • the flow (Q) through a horizontal tube can be described as: Q = -p*D4/(128*m)*dp/dx (Poiseuille's law)

  • => size of the capillary tubes is important!

    Darcy's law

    Water in natural formations

    formation contains water permeability
    aquifer Y high
    aquitard Y low
    aquiclude Y very low
    aquifuge N negligible

    Steady groundwater flow

    Quantifying groundwater flow using flownets

    Heterogeneity and anisotropy

    Resources

  • Manning, J.C. (1997) Applied Principles of Hydrology. Prentice Hall, third edition, 276p.
  • Freeze, R.A. and Cherry, J.A. (1979) Groundwater. Prentice Hall, 604p.