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Leakage over polygons

Leakage over polygons, under Output Specification → Leakage over Polygons, computes vertical leakage discharges integrated over a polygon area. The area may be the area covered by a specified domain, or the area covered by a polygon you define. The discharges are computed by evaluating the vertical leakage rate [L/T] at a large number of regularly spaced points, and numerically integrating contributions over the small increments of area each point represents. The total leakage discharge [L3/T] over the area is reported.

This examines vertical leakages for each level that exists within the domain or polygon. For example, if levels 1, 2, 3, and 5 exist in the area of the polygon, the output includes:

  • downward leakage into the topmost level of the model, regardless of whether the topmost level is level 1, 2, or another level
  • downward leakage out of level 1
  • downward leakage out of level 2
  • downward leakage out of level 3

  • downward leakage out of level 5

  • Label is a text label that helps you keep track of multiple polygon areas.

  • Polygon Source selects whether the polygon is the extent of a model domain, or the coordinates of a polygon, which may cross domain boundaries. The choices are Domain and Coordinates.
  • Points Evaluated is the approximate number of points evaluated. If the polygon is a rectangle parallel to the x and y axes, this number is the actual number of points. If the polygon is irregular, the actual number is less than the number specified here. The spacing is set so that the specified number of points fills a rectangle that encompasses the entire polygon. More points yield more accurate estimates of integrated leakage discharge, at the cost of more computation.
  • Domain sets the domain that defines the polygon area, when Polygon Source is Domain. When Polygon Source is Coordinates, this input is not used and may be left blank.
  • Coordinates are the coordinates of the polygon area, when Polygon Source is Coordinates. When Polygon Source is Domain, this input is not used and may be left blank. Click the edit icon Edit coordinates in this cell to open the coordinate editor, and enter one vertex per line, with x and y separated by a comma. The polygon is closed from the last vertex to the first if you do not repeat the first vertex. To digitise the polygon on the map, click the draw icon Draw polygon and then click each vertex; double-click to close the polygon.

After solving, graph the leakage with the plot results icon Plot Results on the row.