The dialog window "Groundwater mound: circular aquifer" calculates steady state groundwater mounding caused by recharge, that is homogeneously distributed over the whole area of a circular unconfined aquifer or an aquifer of elliptic shape. The aquifer is bounded by Constant Head boundary with the head value that is equal to initial saturated thickness. This hydrodynamic boundary acts as a discharge boundary after start of mounding.
The dialog window is opened by selecting "File > Hydrogeologist workbench > Groundwater mound > Circular aquifer".
"Groundwater mound: circular aquifer" dialog box for a circular aquifer or an aquifer of elliptic shape
The profile and required parameter fields appear on the left side of the dialog window. The right side of the window shows the plan view and the associated required parameter fields. Some of the parameters are the same on the plan and the profile views and they can be entered on the either of them.
Explanatory table
"ε, m/day" text box |
Recharge rate |
"k, m/day" text box |
Hydraulic conductivity of aquifer |
"m, m" text box |
Initial saturated thickness of aquifer. It remains time-constant at the boundary. |
"R, m" text box |
Radius of circular aquifer |
"a, m" and "b, m" text box |
Dimensions of ellipsis. Inputs to text box "a" can be done on plan or profile views. Elipsis sketch is automatically updated based on input values. |
"х, m", "y, m" text box |
Coordinates of the location to determine mounding "s". Distance from the centre of the rectangular area along X and Y axes. The coordinate value can be entered on the plan or the profile views.
To be accounted in calculations, the coordinates must satisfy the conditions below: 1) for a circular aquifer
2) for an elliptic aquifer
Mounding in this type of aquifers is symmetric relatively to the aquifer center. Thus both positive and negative coordinate values return the same results |
"Circular aquifer" and "Aquifer-ellipse" option |
Selection between circular and elliptic aquifers for calculations of mounding |
"s(max), m" and "s, m" text box |
Information field displaying the maximum height of a groundwater mound (smax) and height of a groundwater mound at any distance from the aquifer's center. Maximum mounding occurs in the center of aquifer |
"Q, m^3/day" text box |
Information field displaying discharge rate at the perimeter contour of the aquifer |
The following analytical solutions are used for calculations.
1. Circular aquifer
Mounding in the aquifer's center:
Mounding at radial distance r from the aquifer's center:
where
discharge to the circular drain contour:
2. Ellipsis-shaped aquifer
Mounding in the aquifer's center:
Mounding at distances x and y from the aquifer's center:
discharge to the ellipsis-shaped drain contour:
References
Strack O.D.L. Analytical groundwater mechanics. Cambridge University Press, 2017.