Option

Description

Horton

Max Infiltration Rate

Maximum infiltration rate on the Horton curve (mm/hr or in/hr).

Min Infiltration Rate

Minimum infiltration rate on the Horton curve (mm/hr or in/hr). Equivalent to the saturated hydraulic conductivity. See the Soil Characteristics Table for typical values.

Decay Constant

Infiltration rate decay constant for the Horton curve (1/hours). Typical values range between 2 and 7.

Drying Time

Time in days for a fully saturated soil to dry completely. Typical values range from 2 to 14 days.

Max Infiltration Volume

Maximum infiltration volume possible (mm or inches, 0 if not applicable). Can be estimated as the difference between a soil's porosity and its wilting point, multiplied by the depth of the infiltration zone.

Green Ampt

Suction Head

Average value of soil capillary suction along the wetting front (mm or inches).

Conductivity

Soil saturated hydraulic conductivity (mm/hr or in/hr).

Initial Deficit

Difference between soil porosity and initial moisture content (a fraction). The initial deficit for a completely drained soil is the difference between the soil's porosity and its field capacity.

Curve Number

Curve Number

This is the SCS curve number, which is tabulated in the publication SCS Urban Hydrology for Small Watersheds, 2nd Ed., (TR-55), June 1986.

Consult the SCS Runoff Curve Numbers Table for a listing of values by soil group, and the accompanying Soil Group Table for the definitions of the various groups.

Conductivity

This is the SCS curve number, which is tabulated in the publication SCS Urban Hydrology for Small Watersheds, 2nd Ed., (TR-55), June 1986.

Consult the SCS Runoff Curve Numbers Table for a listing of values by soil group, and the accompanying Soil Group Table for the definitions of the various groups.

Drying Time

The number of days it takes a fully saturated soil to dry. Typical values range between 2 and 14 days.