Characterizing Hydraulic Properties
This chapter presents some of the field and laboratory techniques that are available for obtaining parameters that can be used in quantitative analyses and model simulations of vadose-zone processes. It addresses the portion of a vadose-zone characterization effort that is often critical to its success: planning. The chapter briefly outlines a five-step process that is usually relevant to planning most subsurface site investigations involving the vadose zone; however, the basic outline could apply to almost any hydrogeological investigation. The five-step process are: state the problem that requires solution; develop a preliminary conceptual model of the system; identify an approach to address the problem; identify the data needed to solve the problem; and develop a site characterization work plan. The chapter discusses hydraulic properties of the vadose zone. The principal properties include saturated hydraulic conductivity, unsaturated hydraulic conductivity, air permeability, and specific water capacity.