We study the problem of field-scale infiltration over soils where spatial variability of saturated hydraulic conductivity is represented by a homogeneous correlated log-normal random field. The Green-Ampt equation is used to describe infiltration at the local scale m terms of cumulative infiltration. Expressions for the ensemble mean and variance of field-scale infiltration are developed. Analytical expression is derived for the expected time it takes for a given depth of water to infiltrate into me soil. The results are compared with extensive sets of Monte-Carlo simulations for a wide variety of cases. The simulations reveal that the proposed formulations provide an adequate estimate of the field-scale infiltration, and that the variance of field-scale infiltration can be parameterized through a simple scaling relationship in terms of the correlation length of the saturated hydraulic conductivity field. Simplified expressions for the variance under asymptotic correlation lengths are also presented.
Infiltration over soils with spatially-correlated hydraulic properties
MORBIDELLI, Renato;CORRADINI, Corrado
2000
Abstract
We study the problem of field-scale infiltration over soils where spatial variability of saturated hydraulic conductivity is represented by a homogeneous correlated log-normal random field. The Green-Ampt equation is used to describe infiltration at the local scale m terms of cumulative infiltration. Expressions for the ensemble mean and variance of field-scale infiltration are developed. Analytical expression is derived for the expected time it takes for a given depth of water to infiltrate into me soil. The results are compared with extensive sets of Monte-Carlo simulations for a wide variety of cases. The simulations reveal that the proposed formulations provide an adequate estimate of the field-scale infiltration, and that the variance of field-scale infiltration can be parameterized through a simple scaling relationship in terms of the correlation length of the saturated hydraulic conductivity field. Simplified expressions for the variance under asymptotic correlation lengths are also presented.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.