Monitoring Hydraulic Gradient Using Three-Point Estimator

Abstract

A new method is discussed for garnering information from water level data. Using measured water level data, a series of local estimates of the hydraulic gradient are generated. By combining these estimates through a series of plots, significant insight can be gained regarding the regional gradient and local variability in the gradient. Utility of this approach for monitoring gradients and temporal changes in the gradient is discussed through application to experimental results from a constructed aquifer, field results from a site in northern Indiana, and numerical simulation. In each case, the estimator provided a measure of the regional gradient and local deviation from this regional gradient. It is shown that the shape of the plots generated is related to errors in measurement and local anomalies in the hydraulic gradient. It is suggested that the shape of the plot also provides insight into the relative scales of the measurement and the integral scale of the underlying transmissivity field.