Infiltration and Unsaturated Zone

Abstract

After a review of the basic unsaturated water flow processes, relevant soil and infiltration parameters that control infiltration are introduced such as the soil water retention and unsaturated hydraulic conductivity functions. In addition, a short review of unsaturated water flow and solute transport modeling is presented. In the main part of this chapter, the most frequently used physically based and empirical infiltration equations are introduced. The presentation of the available methods of measuring infiltration and unsaturated water flow includes a section on how specific field tests can be used to characterize soil infiltration parameters. The chapter concludes with a section on a review of spatial considerations of unsaturated soil water flow and infiltration, highlighting research of infiltration measurements and modeling at the basin scale.