ABSTRACT

The existence of hydrogeologic boundaries serves to limit the continuity of most aquifers in one or more directions to distances ranging from a few hundred feet (hundred meters) or less to a few miles (5000 meters) or more. Hydrogeologic boundaries may be divided into two types: barrier and recharge. A barrier boundary is defined as a line (streamline) across which there is no flow and it may consist of folds, faults, or relatively impervious deposits (aquiclude) such as shale or clay. A recharge boundary is defined as a line (equipotential) along which there is no drawdown and it may consist of rivers, lakes, and other bodies of surface water hydraulically connected to the aquifer. Flow net analysis involves a study of potentiometric surface and water table contour maps or profiles and the law of the conservation of mass. A program for producing flow nets, streamline plots, and capture zone maps is listed by Bonn and Rounds.