Elevation-area relationship
A relationship between elevation and storage volume is required to perform detention basin routing calculations. This is obtained by defining areas of horizontal 'slices' through the volume in which water is stored from polygons drawn in CAD programs.
The elevations must be set at points where areas change, as indicated below.
If infiltration is to be modelled in a detention basin, the perimeters of the slices can also be determined at the same elevations as the areas. The elevation-perimeter relationship can be used to define the areas of the sides of the storage that are submerged at various elevations. Water is assumed to pass through these areas in calculating infiltration.
The elevations must be set at points where areas change, as indicated below.
If infiltration is to be modelled in a detention basin, the perimeters of the slices can also be determined at the same elevations as the areas. The elevation-perimeter relationship can be used to define the areas of the sides of the storage that are submerged at various elevations. Water is assumed to pass through these areas in calculating infiltration.