Green-Ampt approximations

被引：50

作者：

Barry, DA ^{[1
]}

Parlange, JY

Li, L

Jeng, DS

Crapper, M

机构：

[1] Ecole Polytech Fed Lausanne, Sch Architecture Civil & Environm Engn, CH-1015 Ecublens, Switzerland

[2] Cornell Univ, Dept Biol & Environm Engn, Ithaca, NY 14853 USA

[3] Univ Queensland, Sch Engn, Brisbane, Qld 4072, Australia

[4] Hohai Univ, Ctr Ecoenvironm Modelling, Nanjing 210098, Peoples R China

[5] Univ Sydney, Dept Civil Engn, Sydney, NSW 2006, Australia

[6] Univ Edinburgh, Sch Engn & Elect, Inst Infrastruct & Environm, Contaminated Land Assessment & Remediat Res Ctr, Edinburgh EH9 3JL, Midlothian, Scotland

来源：

ADVANCES IN WATER RESOURCES | 2005年 / 28卷 / 10期

关键词：

Lambert W-1 function approximations; asymptotic expansions; branch point; iteration scheme;

D O I：

10.1016/j.advwatres.2005.03.010

中图分类号：

TV21 [水资源调查与水利规划];

学科分类号：

081501 ;

摘要：

The solution to the Green and Ampt infiltration equation is expressible in terms of the Lambert W-1 function. Approximations for Green and Ampt infiltration are thus derivable from approximations for the W-1 function and vice versa. An infinite family of asymptotic expansions to W-1 is presented. Although these expansions do not converge near the branch point of the W function (corresponds to Green-Ampt infiltration with immediate ponding), a method is presented for approximating W-1 that is exact at the branch point and asymptotically, with interpolation between these limits. Some existing and several new simple and compact yet robust approximations applicable to Green-Ampt infiltration and flux are presented, the most accurate of which has a maximum relative error of 5 x 10(-5)%. This error is orders of magnitude lower than any existing analytical approximations. (c) 2005 Elsevier Ltd. All rights reserved.

引用

页码：1003 / 1009

页数：7

共 37 条

[1] A CLASS OF EXACT-SOLUTIONS FOR RICHARDS EQUATION [J].