Optimal Management of Groundwater Monitoring Networks in Highly Heterogeneous Aquifers

Abstract

The increasing concerns about groundwater resources make managing such resources a must. Monitoring networks are the basis of any management process. Therefore, these networks are the main sources of information and have to result in very accurate outputs, which needs a huge number of observation wells. Nevertheless, increasing the number of wells means increasing the cost and the time consumed in collecting this data, especially if it were collected manually. The aim of this research is to build an optimized monitoring network that satisfies the need for accurate output while having the minimum number of wells necessary to make it cost-efficient. The accuracy of the output depends on the objective of the monitoring, which is a decision-maker task. Therefore, it was argued to deduce a relation between the accuracy required and the minimum number of wells to be observed. To reach this target, a geostatistical approach was used. It was found that the most suitable geostatistical model for interpolating groundwater-level data collected from District VI, El-Obour City using GIS was found to be the ordinary kriging method, fitted with Gaussian function. The data had to be normalized using Box-Cox with power parameter 2, and no external trend affected the data. All of them together compose the best matched model for the studied area to generate a prediction error map with good accuracy that was used further to optimize the existing monitoring network. Nevertheless, different relations between the accuracy and the number of wells were deduced in both graphical and analytical ways. Also, a tabulated confrontation between each of the resultant relations was created.