Evaluating Aquifer Parameters For Analytical Groundwater Models On Contaminated Sites
Free (open access)
S. B. Anim-Addo & I. David
The estimation of area-specific hydro-geological parameters or coefficients (HGPCs) for groundwater modelling through conventional methods such as Pump Tests may not be suitable for contaminated sites, as these infiltration/extraction Tests may lead to inestimable additional risks of contaminant spread to protected zones and settlements. For early detection and control of contaminant plume transport behaviour, homogenized models of the affected site are important and reasonably accurate sources of information for decision makers. Measured data from bore profiles and groundwater monitoring stations and measuring wells provide the most reliable and formalised source of information on subsurface soil layers in most countries. This paper presents a method for estimating homogenized HGPCs for groundwater modelling and simulation, based on these data. The calculation method uses a spatially weighted averaging technique that incorporates an adaptation of the Voronoi algorithms in the plane as well as the thicknesses of soil layers recorded in each MWB. Each characteristic local HGPC is calculated separately. In a number of examples, the Paper underpins the assertion that a spatially weighted estimate of HGPCs provides a high accuracy for the modelling parameters, and for simulation results for the flow and transport of contaminant plumes in aquifer. Finally, a software tool for carrying out the estimation of groundwater parameters effectively is discussed, based on the presented method.