Simulation of dye pattern
  Home
  Research
  Publication
  Presentations
  Interests
  Links
 
       
 
       

Introduction
         

Overview

      

Water flow in macropores is an important mechanism of infiltration in natural soils and as such is crucial for the prediction of runoff generation. The major flow processes controlling macropore flow are the initiation of macropore flow (water supply into macropores) and the water transfer from the macropores into the surrounding soil matrix (interaction).

         

Experi-
ments

      

Experimental plot The water movement during infiltration and the resulting flow paths were studied with combined sprinkling and dye tracer experiments under different rainfall intensities and initial soil moisture conditions. The chosen rainfall intensity mimics a convenctive (60 mm/h) and an advective (12 mm/h) rainfall event. The dye tracer was continuously applied with the sprinkling water on 1 m2 plots. After the sprinkling, horizontal and vertical soil sections were prepared for surveying dye patterns, which showed the cumulated flow pathways in the soils. These experiments were carried out on three hillslope sites covered with grassland, where earthworms mainly built the macropore system.

         

Sites

      

The following table shows the soil properties of the three experimental sites in Switzerland.

Site

Soil Classification

Geological parent material

Average values at 30-80 cm depth

Density
(g cm-3)

Soil texture

Macro-porosity
(%)

Macropore Density(m2)

Rietholzbach

Mollic Cambisol

Conglomerates (molasse)

1.30

clay loam

0.35

228

Heitersberg

Umbric Cambisol

Moraine

1.65

loam

0.41

357

Niederweningen

Eutric Cambisol

Sandstone (molasse)

1.45

sandy loam

0.77

623

         

IN3M

      

Concept of IN3M The process understanding and results from the combined sprinkling and dye tracer experiments were used to develop the INfiltration-INitiation-INteraction Model (IN3M), which describes vertical and horizontal infiltration with a consistent and stable approach (Green-Ampt), uses physically-based parameters that can be derived from soil properties, and simulates the interaction for each macropore. Because of the unique structure of IN3M, dye patterns can be simulated and the results can be compared with the resulting dye patterns from the sprinkling experiments.
The simulation of dye patterns illustrates the variety of different processes and infiltration characteristics in macroporous soils. The simulation can also help to better understand how water moves in structured soils.
Details to the experiments and IN3M can be found in my Ph.D. thesis.

         

© Markus Weiler 3/2002