Analytical Solutions for One-Dimensional Water Flow in Vegetated Layered Soil

Vegetation reduces soil pore-water pressure (PWP) through root water uptake. There are limited studies about the effects of vegetation on PWP distributions in layered soil, such as multilayered earthen landfill cover. New analytical solutions for vertical water flow in vegetated layered soil at steady state are derived considering various root architectures, including exponential, parabolic, triangular, and uniform roots. The solutions are verified through (1) hypothetical vegetated layered soil using numerical seepage analyses and (2) a soil column test investigating PWP distributions in vegetated layered soil. The new solutions are capable of determining PWP distributions for both inside and outside root zone in vegetated layered soil. These solutions provide a relatively simple and reliable approach for estimation of PWP distributions in vegetated layered soil.