Measurement and modeling of the spatial variability of infiltration on rangeland watersheds

Persistent Link:
http://hdl.handle.net/10150/284225
Title:
Measurement and modeling of the spatial variability of infiltration on rangeland watersheds
Author:
Paige, Virginia Burton
Issue Date:
2000
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Infiltration processes on rangeland watersheds are highly variable in both space and time due to heterogeneities in soil properties and temporal variability of rainfall, as well as vegetation, cover and topographic characteristics. Infiltration processes at the plot scale are often described and modeled using a single hydraulic conductivity (Ke) parameter. In this study, the spatial variability of infiltration processes at the plot scale is examined using an integrated measurement and modeling approach. A newly developed variable intensity rainfall simulator is effectively used to measure changes in plot scale infiltration rate with changes in rainfall intensity. In addition, process-based hydrologic simulation models are used to determine the amount of complexity needed to accurately model the observed runoff response from the rainfall simulator experiments. First, a soil box lysimeter is used to measure variability of infiltration processes and runoff response due to soil texture and rainfall intensity. Second, five natural field plots in a rangeland watershed are used to measure the same processes with additional complexity in the form of cover and topographic characteristics. Steady-state infiltration rates increased with rainfall intensity on all of the plots, indicating partial area response and spatial variability of infiltration within each plot. Evaluation of the soil box lysimeter infiltration experiments showed that the location of areas with higher and lower infiltration capacities along a flow path does have an important effect on runoff response and that the response changes with changes in rainfall intensity. Using the detailed measurements of the field plot vegetative cover and surface characteristics of the plots to discretize the plots into separate overland flow planes improved the ability to model the variability of infiltration processes and the observed runoff response. Multi-plane configurations parameterized based on soil and plot characteristics resulted in a significant improvement over single plane configurations. The measurement and simulation model results show that the rainfall runoff relationship cannot be accurately described or modeled using a single Ke value at the plot scale.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Hydrology.; Environmental Sciences.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Renewable Natural Resources
Degree Grantor:
University of Arizona
Advisor:
Stone, Jeffry J.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleMeasurement and modeling of the spatial variability of infiltration on rangeland watershedsen_US
dc.creatorPaige, Virginia Burtonen_US
dc.contributor.authorPaige, Virginia Burtonen_US
dc.date.issued2000en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractInfiltration processes on rangeland watersheds are highly variable in both space and time due to heterogeneities in soil properties and temporal variability of rainfall, as well as vegetation, cover and topographic characteristics. Infiltration processes at the plot scale are often described and modeled using a single hydraulic conductivity (Ke) parameter. In this study, the spatial variability of infiltration processes at the plot scale is examined using an integrated measurement and modeling approach. A newly developed variable intensity rainfall simulator is effectively used to measure changes in plot scale infiltration rate with changes in rainfall intensity. In addition, process-based hydrologic simulation models are used to determine the amount of complexity needed to accurately model the observed runoff response from the rainfall simulator experiments. First, a soil box lysimeter is used to measure variability of infiltration processes and runoff response due to soil texture and rainfall intensity. Second, five natural field plots in a rangeland watershed are used to measure the same processes with additional complexity in the form of cover and topographic characteristics. Steady-state infiltration rates increased with rainfall intensity on all of the plots, indicating partial area response and spatial variability of infiltration within each plot. Evaluation of the soil box lysimeter infiltration experiments showed that the location of areas with higher and lower infiltration capacities along a flow path does have an important effect on runoff response and that the response changes with changes in rainfall intensity. Using the detailed measurements of the field plot vegetative cover and surface characteristics of the plots to discretize the plots into separate overland flow planes improved the ability to model the variability of infiltration processes and the observed runoff response. Multi-plane configurations parameterized based on soil and plot characteristics resulted in a significant improvement over single plane configurations. The measurement and simulation model results show that the rainfall runoff relationship cannot be accurately described or modeled using a single Ke value at the plot scale.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectHydrology.en_US
dc.subjectEnvironmental Sciences.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineRenewable Natural Resourcesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorStone, Jeffry J.en_US
dc.identifier.proquest9992049en_US
dc.identifier.bibrecord.b41165986en_US
All Items in UA Campus Repository are protected by copyright, with all rights reserved, unless otherwise indicated.