The effect of sorptivity on cumulative infiltration

Abstract

Hydraulic parameters of the soil play a considerable role in the hydrological cycle, irrigation planning, drainage, groundwater recharge, and water resources management. One of the most important hydraulic parameters of the soil is sorptivity (S), yet there is insufficient research on how it affects the mechanism of infiltration. The main scope of this study is to investigate the effect(/significance) of sorptivity on the mechanism of infiltration of water, through various types of soil medium, from both mathematical and experimental perspectives. For this scope, the absolute sensitivity analysis factor of sorptivity was obtained, while two experimental procedures were carried out in the laboratory. Each soil sample was packed into a vertical column, while a constant head of 2 mm was applied at the surface of the soil. The incoming water was measured volumetrically and at the same time, soil moisture, at certain locations, was measured using the TDR method. Sorptivity of each soil was calculated using Parlange's equation. Absolute sensitivity analysis factor of sorptivity showed that for a longer duration/period of cumulative infiltration, sorptivity strongly affects the phenomenon the more synectic the soil type. Thus, estimating sorptivity of the soil could lead to better solutions for irrigation planning, flood prediction and water saving. HIGHLIGHTS Three soil samples sand (S), sandy loam (SL) and loamy sand (LS) were used.; Hydraulic conductivity at saturation of each soil was measured in the laboratory.; Large time of cumulative infiltration influences the sorptivity.; Equations of diffusivity (D) were obtained using using analytical and arithmetic methods.;

Keywords

• cumulative infiltration
• diffusivity
• soil column
• sorptivity