Inverse Analysis Implementation of the SUTRA Ground-Water Model

Abstract

Numerical simulation of ground-water flow and transport is often impeded by a lack of information regarding the conceptual model and properties that best represent the water-bearing formation. Inverse analysis assists in the estimation of the properties of the formation once a defensible form of the conceptual model is defined. In essence, inverse analysis reverses the direction of model application to determine the properties that best match data collected from the formation under investigation. This paper describes the development of an inverse analysis implementation of the well-known and versatile SUTRA model of ground-water flow and transport. The inverse analysis algorithm retains the extensive functionality of SUTRA in forward simulation and allows various forms of parameter constraints to be stipulated. Addition of inverse analysis functionality to an existing ground-water model circumvents the development of redundant models, reduces development time, and ensures the consistent and concurrent development of predictive and interpretive capabilities. Two example analyses are presented to demonstrate a portion of the functionality of the novel inverse analysis algorithm.