Effects of Highly Permeable Geological Discontinuities upon Groundwater Productivity and Well Yield

Abstract

It is generally understood that groundwater flow is greatly affected by linear features associated with geologic structures such as fractures, faults, lithologic boundaries, and fold axes. In crystalline rock aquifers, such geologic structures seem to be closely related to large-scale groundwater flow field and well productivity. However, quantification of how the structures are related with the flow and well productivity is not so simple, because it involves many factors of hydraulic properties and flow phenomena. This study proposes a semianalytical method to analyze the effects of highly permeable geologic discontinuities on the groundwater flow system. Effects of geological discontinuities on groundwater productivity are interpreted from the geometry of linear geologic features by the conformal mapping of the spatial distribution function. The proposed method is compared with the numerical methods, and the applicability and usefulness of the method to delineate high well yield areas from a limited number of well productivity measurements is discussed.