Unconfined Ground-Water Flow to Multiple Wells

The purpose of this paper is to clarify the nature of unconfined flow to single and multiple wells, and to present a method of solving problems associated with this type of flow. The effect of the capillary fringe on the location of the free surface .and the form of the flow patterns; the zone of validity of the Dupuit equation, the shape of the free surface near the well, and the variation: in the stream surface spacing are all discussed. A functional relationship independent of the radius of influence is established, relating the variables at the well; this relationship applies to both single and multiple wells. A fundamental dimensionless parameter consisting of a ratio of the Froude number to the Reynolds number is formulated that characterizes the shape of the cone of depression around a well. The concepts of well efficiency and effectiveness are clarified and guides are presented for their correct use.