Investigation into Subsurface Sampling and Characterization Efficiency Using a High Resolution GIS Based Three Dimensional Earth System

摘要

The degree of homogeneity, dimensions, and anisotropy of a contaminant source zone (SZ) distribution gradient should allow one to roughly estimate the most cost effective three dimensional sampling resolution and method. We have quantified the effect that three dimensional systematic sampling density has on conceptual site model error. A high resolution Earth System Simulator (ESS) was applied to three investigative subsurface direct sensing case studies, plus a synthetic high resolution control site. The ESS has a resolution of 5ft in the horizontal and 0.05 feet in the vertical. Site dimensions were 400ft x 300ft x 21ft with a total of 2,080,161 nodes. A square centered systematic sampling method was used in the sampling and characterization simulation effort. Accounting for high SZ heterogeneity, this research has shown that increasing vertical sampling resolution from 2ft to 0.1ft can decrease normalized model error on average 40% or more while reducing total characterization costs.