| Author | Varshney, Peeyush |
| Call Number | AIT Thesis no. AE-89-60 |
| Subject(s) | Seepage
|
| Note | A thesis submitted in partial fulfilment of the requirements for
the degree of Master of Engineering, School of Environment, and Development |
| Publisher | Asian Institute of Technology |
| Abstract | The present research was undertaken at the International
Crops Research Institute for the Semi-Arid Tropics {ICRISAT) ,
Hyderabad , India, to study the infiltration behaviour in layered
and crusted Alfisols, one of the predominant soil groups found in
the Semi-Arid Tropical region. Extensive field experiments were
done for infiltration measurements required in the determination
of key parameters for model formulation.
A model for analyzing water infiltration into layered soil
profiles with crusting phenomenon, under rainfall application is
developed, using the Green and Ampt approach. The model developed
predicts the reduction in infiltration rate caused by surface
sealing/ crusting and the consequent behaviour of infiltration in
layered profile, the time at which surface saturation occurs and
describes the infiltration thereafter. Prior to surface
saturation stage, the infiltration rate in the soil is equal to
the rain application rate.
The model contains seven measurable input parameters, which
are based on properties and initial soil profile conditions. The
key parameters of the model namely, saturated hydraulic
conductivity, effective wetting suction front, were measured by
Guelph Permeameter and Air-Entry Permeameter simultaneously . The
moisture content deficit was determined by the gravimetric method
of oven drying. The model results are compared with the results
obtained from a rainfall simulator field data, on three different
soil textures with 75%, 85% and 95% sand.
It was found from measurements of crust thickness and
observed data, that the effect of surface sealing decreases as
sand content in the soil profile increases. Predicted results of
the model and the observed results from the rainfall simulator
showed in limited cases good agreement and proved the
applicability of the Green Ampt approach to incorporate various
ameliorating measures which can control this soil crusting
phenomenon and predict accurately the infiltration behaviour in
the soil under diversified field conditions. |
| Year | 1989 |
| Type | Thesis |
| School | School of Environment, Resources, and Development |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Murty, V.V.N
; |
| Examination Committee(s) | Nielsen, Jens Moller ;Paudyal, Guna N. ; |
| Scholarship Donor(s) | The Government of Japan ; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1989 |