PROBLEMS - Hydrogeology: Objectives, Methods, Applications - page 331

Figure 6 Piezometry of the Lower Durance aquifer.

Question: What is the discharge through the cross-sections I to VI?

Table 7 Hydrodynamic and geometric data for the Lower Durance aquifer (to be
completed).

Location Permeability width of

section

saturated
thickness

saturated
cross-
section

hydraulic
gradient

discharge

m·s -1 m m m 2 m·m -1 m 3 ·s -1

I Jouques 1·10 -2 500 4 1/120

II St Estève-
Janson

2·10 -2 600 1 1/200

III Mallemort 5·10 -3 1,500 2 1/600

IV Sud
Sénas

4·10 -3 3,500 2 1/500

V Nord
Alpilles

3·10 -3 19,000 1 1/100

VI Ouest
Lubéron

1·10 -2 10,000 7 1/1500

Answer:

Based on the piezometric map, the hydrodynamic data (permeability), and
a few geometric parameters, one can estimate the discharge of aquifers by
applying Darcy's Law: Q = K·S·i

Where: Q is discharge in m 3 ·s -1 ; K is permeability in m 3 ·s -1 ; S is the saturated
cross-section in m 2 ; i is the hydraulic gradient in m·m -1 .