MONITORING HYDRAULIC-GRADIENT USING 3-POINT ESTIMATOR

A new method is discussed for garnering information from water level d ata. Using measured water level data, a series of local estimates of t he hydraulic gradient are generated. By combining these estimates thro ugh a series of plots, significant insight can be gained regarding the regional gradient and local variability in the gradient. Utility of t his approach for monitoring gradients and temporal changes in the grad ient is discussed through application to experimental results from a c onstructed 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 gradie nt. It is shown that the shape of the plots generated is related to er rors 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 unde rlying transmissivity field.