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Geoelectrics and geostatistics for characterizing ground water protection zones
Abstract
The dissertation is directed at developing a set of methodological tools for characterizing the protection and yield of ground water reservoirs. In each method, geophysical observations are used for supplementing data from traditional measurements (e.g., well logs, specific capacity and pumping tests), and geostatistics, specifically cokriging and compound kriging for combining the different source of information. The manuscript is divided into four main sections. The first part describes a method for characterizing aquifer protective properties (e.g. thickness and continuity) of subsurface layers with low hydraulic conductivity. Data estimated from wells and derived from electrical resistivity measurements are used to map the thickness of a protective clay layer using cokriging. The second section presents a procedure for evaluating wellhead protection zones for existing wells by mapping the corresponding travel times. Travel times are calculated assuming a fixed protection zone around each well. In the third section, a methodology is developed for delineating areas for new wells where the yield for the wells and the effectiveness of protection zones around the wells are jointly considered criteria. The method has been developed for leaky aquifer settings and the effectiveness of a protection zone is characterized by the corresponding travel time. The 'best' well locations are determined using composite programming, a multi-criteria decision making (MCDM) technique. Section four presents an approach to observation network design for selecting the most appropriate location for water supply wells over an area. The method considers measurement network alternatives combining wells and geoelectric measurements. The best observation network is selected by jointly considering the estimation error and cost for each candidate network in a MCDM analysis. Each method is illustrated through examples using real data.
Subject Area
Geotechnology|Civil engineering
Recommended Citation
Pesti, Geza, "Geoelectrics and geostatistics for characterizing ground water protection zones" (1993). ETD collection for University of Nebraska-Lincoln. AAI9322808.
https://digitalcommons.unl.edu/dissertations/AAI9322808