Hydrologic Characterization and Measurements

Abstract

This chapter focuses attention upon the unique hydrologic characteristics of fractured and karst aquifers and the wide range of measurements that can be utilized to characterize them. At this stage of the characterization we should have a well-developed geologic conceptual model of conditions with many of the questions about the site already answered (Tables 13.1 , 13.2 and 13.3 ). We should already know the type of surface hydrologic features at the site; the surface water and groundwater boundaries, in general if not in detail; the depth, thickness and level of complexity of the epikarst; whether the aquifer is confi ned or unconfi ned, and whether there is more than one. In addition, we will have preliminary data from existing monitoring wells or initial borings on water levels, potentiometric surfaces and fl ow directions. The objectives for this phase of work will focus upon the details to quantify and support our conceptual model. This is obviously important for projects focused on groundwater resources or contaminant remediation. But surface and groundwater in a fractured or karst setting will also impact most engineered structures, if not managed well they can result in unstable conditions.

Subsurface imaging of water electrical conductivity, hydraulic permeability and lithology at contaminated sites by induced polarization

“…This requires information on the spatial 56 distribution of the contaminant plume, local geology, and hydrogeological properties (e.g. 57 permeability, k), which are conventionally estimated from analysis of groundwater samples, of soil 58 samples, and of aquifer tests (EPA, 1991;Cameron, 1992;Benson and Yuhr, 2016a). These 59 approaches require many drillings to sufficiently characterize field sites, which is often unfeasible 60 at large sites (Benson and Yuhr, 2016b).…”