Simple Equations For Hooghoudt Equivalent Depth

Abstract

Due to its simplicity and relative accuracy as compared with other more elaborate and hence more complicated methods, the Hooghoudt solution to the drainage design problem is widely used by the practicing engineer. In addition, it is the notion of equivalent depth that Hooghoudt introduced, which makes his analysis more important. The equivalent depth has gained considerable significance in the treatment of the transient drainage problem based on the Dupuit-Forchheimer theory. For calculations on a computer in solving the transient flow problems, the computation of the equivalent depth requires the storage in the computer memory of an appreciable size table (maximum 300 values). For a faster determination of the equivalent depth, and to avoid storage of a table in the computer memory, approximate formulas have been introduced. After the detailed reworking of the solution of Hooghoudt equations, it was considered appropriate to proceed with finding simple algebraic equations which approximate the equivalent depth in a more satisfactory way. This is the subject of the present note.