Hydrogeological Decision Analysis: 1. A Framework

Abstract This paper is the first in a four‐part series that describes the application of decision analysis to engineering design for projects in which the hydrogeological environment plays an important role. The methodology is well‐suited to the design of containment facilities at new waste‐management facilities, purge‐well networks in contaminant remediation applications, or drainage systems in geotechnical projects. It is based on a risk‐based philosophy of engineering design. It involves the coupling of three separate models: a decision model based on a risk‐cost‐benefit objective function, a simulation model for ground‐water flow and transport, and an uncertainty model that encompasses both geological uncertainty and parameter uncertainty. The approach can be used for the comparison of alternative engineered components of a system, for the design of monitoring systems, and for the assessment of data worth in the design of site investigation programs. This first paper lays the framework; the subsequent papers escribe how the methods can be applied in geotechnical and waste‐management applications.