SSgampt: A Green-Ampt water infiltration model

Description Usage Arguments Details Value Author(s) References See Also Examples

Description

This is a two- parameter function to determine water infiltration parameters contained in the Green-Ampt infiltration model

Usage

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SSgampt(input, ks, A)

Arguments

input

Instantaneous infiltration rate

ks

Saturated hydraulic conductivity

A

Constant incorporating matric suction potential, wetting front, and antecedent moisture content

Details

This is a self-starting model for estimating Green-Ampt infiltration model using instantaneous and cumulative infiltration data

Value

A list of objects returned by standard R regression functions such as nls and lm

Author(s)

Christian Thine Omuto

References

Green WA and Ampt GA. 1911. Studies on soil physics: 1. The flow of air and water through soils. Journal of Agricultural Science 4: 1-24

See Also

SSphilip, SShorton

Examples

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##Load the data
data(infilt)
gamp.ns=nlsLM(Cumrate~SSgampt(Rate,ks,A), infilt)
summary(gamp.ns)

Example output

Loading required package: nlme
Loading required package: minpack.lm

Formula: Cumrate ~ SSgampt(Rate, ks, A)

Parameters:
   Estimate Std. Error t value Pr(>|t|)    
ks 15.33111    0.40690   37.68   <2e-16 ***
A  -0.70344    0.06312  -11.14   <2e-16 ***
---
Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

Residual standard error: 10.11 on 1103 degrees of freedom

Number of iterations to convergence: 2 
Achieved convergence tolerance: 1.49e-08

HydroMe documentation built on May 29, 2017, 2:58 p.m.