GIS Procedure for Developing Three‐Dimensional Subsurface Profile

Abstract

A geographic information system (GIS)‐based procedure for developing subsurface profiles from well‐log data is developed. The well‐log data base is constructed from a series of borehole geophysical logs. Interpretation of geophysical and formation well logs is discussed. The GIS procedure is developed to target a modeling area and interpolate the well‐log data base to create a three‐dimensional representation of the subsurface environment. Any number of cross‐sectional profiles or three‐dimensional images of well‐log data can be created and viewed interactively. From the generated profile information, a vertical discretization of the study area is defined. For each of the denoted subsurface units, a GIS‐MODFLOW interface computes the geohydrologic parameters from the GIS well‐log data base. The well‐log data is analyzed and output in a format compatible with the input data structure of the ground‐water flow model MODFLOW. An example modeling problem demonstating the range and versatility of the well‐log data base and the GIS‐MODFLOW interface is presented.