{"id":{"repo_id":"alabama","oai_identifier":"oai:ir.ua.edu:123456789/9466"},"canonical_url":"https://search.dev.ndltd.org/etd/alabama/oai:ir.ua.edu:123456789/9466","repository":{"repo_id":"alabama","name":"University of Alabama","base_url":"https://ir-api.ua.edu/oai/request"},"display":{"title":"Small Scale Aeolian Processes and Landform Response","abstract":"When the wind blows across a surface with erodible grains, it exerts a shear stress on the surface. When the strength of the wind increases, those grains on the surface can be moved. The transported grains exchange momentum with fluid flow, interact with the surface, and then finally settle down when the wind strength becomes too weak to maintain their motion. The deposited grains produce various landforms from centimeter-scale sand ripples to meter- or kilometer-scale dunes and dune fields on terrestrial and extraterrestrial surfaces. In this dissertation, I investigated three subjects concerning small-scale aeolian processes and landforms: 1) the mechanisms of the low-energy creep mode of sand motion, especially the proportion of creep relative to the total transport within the aeolian system; 2) a method to efficiently delineate grainflow boundaries from a dune slipface; and 3) grainflow morphology characteristics on dunes of different sizes. To address these understudied topics, I integrated field data, signal and image processing techniques, and remote sensing and GIS techniques, to elucidate questions and arguments relevant to the study of aeolian processes and landforms.This dissertation focuses on aeolian landforms that respond quickly to forcing processes by studying creep motion and grainflow morphology. We reviewed the literature on aeolian creep and found a fundamental deficit in the understanding of the sand transport system. We argued for an agreement on creep definition and accompanying measurement methods. We developed an algorithm to objectively and efficiently delineate grainflow boundaries. It is an essential tool to study aeolian processes on slipfaces and is also applicable to the broader family of geophysical flows. we addressed grainflow morphology on two relatively large dunes. The quantification and classification of grainflow morphology showed that grainflow shapes were dune-size dependent. The findings of this dissertation are relevant to the formation and evolution of aeolian landforms with associated processes.","abstract_html":"When the wind blows across a surface with erodible grains, it exerts a shear stress on the surface. When the strength of the wind increases, those grains on the surface can be moved. The transported grains exchange momentum with fluid flow, interact with the surface, and then finally settle down when the wind strength becomes too weak to maintain their motion. The deposited grains produce various landforms from centimeter-scale sand ripples to meter- or kilometer-scale dunes and dune fields on terrestrial and extraterrestrial surfaces. In this dissertation, I investigated three subjects concerning small-scale aeolian processes and landforms: 1) the mechanisms of the low-energy creep mode of sand motion, especially the proportion of creep relative to the total transport within the aeolian system; 2) a method to efficiently delineate grainflow boundaries from a dune slipface; and 3) grainflow morphology characteristics on dunes of different sizes. To address these understudied topics, I integrated field data, signal and image processing techniques, and remote sensing and GIS techniques, to elucidate questions and arguments relevant to the study of aeolian processes and landforms.This dissertation focuses on aeolian landforms that respond quickly to forcing processes by studying creep motion and grainflow morphology. We reviewed the literature on aeolian creep and found a fundamental deficit in the understanding of the sand transport system. We argued for an agreement on creep definition and accompanying measurement methods. We developed an algorithm to objectively and efficiently delineate grainflow boundaries. It is an essential tool to study aeolian processes on slipfaces and is also applicable to the broader family of geophysical flows. we addressed grainflow morphology on two relatively large dunes. The quantification and classification of grainflow morphology showed that grainflow shapes were dune-size dependent. The findings of this dissertation are relevant to the formation and evolution of aeolian landforms with associated processes.","abstract_has_math":false,"creators":["Zhang, Pei"],"institution":"University of Alabama Libraries","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Liu, Hongxing","Parteli, Eric J.","Ellis, Jean T","Cohen, Sagy"],"advisors":["Sherman, Douglas J."],"committee_chairs":[],"committee_members":[],"year":2022,"date_issued":"2022","date_published":"2022","updated_at":"2026-07-27T18:44:27Z","subjects":[],"languages":["en_US","English"],"rights":["All rights reserved by the author unless otherwise indicated."],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["http://purl.lib.ua.edu/186480","u0015_0000001_0004439","Zhang_alatus_0004D_14908"],"render_values":[{"text":"http://purl.lib.ua.edu/186480","href":"http://purl.lib.ua.edu/186480","code":true},{"text":"u0015_0000001_0004439","href":null,"code":true},{"text":"Zhang_alatus_0004D_14908","href":null,"code":true}]}]},"links":{"outbound_url":"https://ir.ua.edu/handle/123456789/9466","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Liu, Hongxing","Parteli, Eric J.","Ellis, Jean T","Cohen, Sagy"]},{"key":"dc:contributor.advisor","label":"Advisor","values":["Sherman, Douglas J."]},{"key":"dc:contributor.other","label":"Dc Contributor Other","values":["University of Alabama Tuscaloosa"]},{"key":"dc:creator","label":"Author","values":["Zhang, Pei"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2022-09-28T14:54:48Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2022-09-28T14:54:48Z"]},{"key":"dc:date.issued","label":"Date","values":["2022"]},{"key":"dc:publisher","label":"Institution","values":["University of Alabama Libraries"]},{"key":"dc:type","label":"Dc Type","values":["thesis","text"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]},{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]},{"key":"dc:rights","label":"Dc Rights","values":["All rights reserved by the author unless otherwise indicated."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["http://purl.lib.ua.edu/186480","u0015_0000001_0004439","Zhang_alatus_0004D_14908"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://ir.ua.edu/handle/123456789/9466"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Electronic Thesis or Dissertation"]},{"key":"dc:description.abstract","label":"Abstract","values":["When the wind blows across a surface with erodible grains, it exerts a shear stress on the surface. When the strength of the wind increases, those grains on the surface can be moved. The transported grains exchange momentum with fluid flow, interact with the surface, and then finally settle down when the wind strength becomes too weak to maintain their motion. The deposited grains produce various landforms from centimeter-scale sand ripples to meter- or kilometer-scale dunes and dune fields on terrestrial and extraterrestrial surfaces. In this dissertation, I investigated three subjects concerning small-scale aeolian processes and landforms: 1) the mechanisms of the low-energy creep mode of sand motion, especially the proportion of creep relative to the total transport within the aeolian system; 2) a method to efficiently delineate grainflow boundaries from a dune slipface; and 3) grainflow morphology characteristics on dunes of different sizes. To address these understudied topics, I integrated field data, signal and image processing techniques, and remote sensing and GIS techniques, to elucidate questions and arguments relevant to the study of aeolian processes and landforms.This dissertation focuses on aeolian landforms that respond quickly to forcing processes by studying creep motion and grainflow morphology. We reviewed the literature on aeolian creep and found a fundamental deficit in the understanding of the sand transport system. We argued for an agreement on creep definition and accompanying measurement methods. We developed an algorithm to objectively and efficiently delineate grainflow boundaries. It is an essential tool to study aeolian processes on slipfaces and is also applicable to the broader family of geophysical flows. we addressed grainflow morphology on two relatively large dunes. The quantification and classification of grainflow morphology showed that grainflow shapes were dune-size dependent. The findings of this dissertation are relevant to the formation and evolution of aeolian landforms with associated processes."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["electronic"]},{"key":"dc:format.mimetype","label":"Dc Format Mimetype","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Small Scale Aeolian Processes and Landform Response"]}]}],"canonical_facts":{"dc:contributor":["Liu, Hongxing","Parteli, Eric J.","Ellis, Jean T","Cohen, Sagy"],"dc:contributor.advisor":["Sherman, Douglas J."],"dc:contributor.other":["University of Alabama Tuscaloosa"],"dc:creator":["Zhang, Pei"],"dc:date.accessioned":["2022-09-28T14:54:48Z"],"dc:date.available":["2022-09-28T14:54:48Z"],"dc:date.issued":["2022"],"dc:description":["Electronic Thesis or Dissertation"],"dc:description.abstract":["When the wind blows across a surface with erodible grains, it exerts a shear stress on the surface. When the strength of the wind increases, those grains on the surface can be moved. The transported grains exchange momentum with fluid flow, interact with the surface, and then finally settle down when the wind strength becomes too weak to maintain their motion. The deposited grains produce various landforms from centimeter-scale sand ripples to meter- or kilometer-scale dunes and dune fields on terrestrial and extraterrestrial surfaces. In this dissertation, I investigated three subjects concerning small-scale aeolian processes and landforms: 1) the mechanisms of the low-energy creep mode of sand motion, especially the proportion of creep relative to the total transport within the aeolian system; 2) a method to efficiently delineate grainflow boundaries from a dune slipface; and 3) grainflow morphology characteristics on dunes of different sizes. To address these understudied topics, I integrated field data, signal and image processing techniques, and remote sensing and GIS techniques, to elucidate questions and arguments relevant to the study of aeolian processes and landforms.This dissertation focuses on aeolian landforms that respond quickly to forcing processes by studying creep motion and grainflow morphology. We reviewed the literature on aeolian creep and found a fundamental deficit in the understanding of the sand transport system. We argued for an agreement on creep definition and accompanying measurement methods. We developed an algorithm to objectively and efficiently delineate grainflow boundaries. It is an essential tool to study aeolian processes on slipfaces and is also applicable to the broader family of geophysical flows. we addressed grainflow morphology on two relatively large dunes. The quantification and classification of grainflow morphology showed that grainflow shapes were dune-size dependent. The findings of this dissertation are relevant to the formation and evolution of aeolian landforms with associated processes."],"dc:format.medium":["electronic"],"dc:format.mimetype":["application/pdf"],"dc:identifier.other":["http://purl.lib.ua.edu/186480","u0015_0000001_0004439","Zhang_alatus_0004D_14908"],"dc:identifier.uri":["https://ir.ua.edu/handle/123456789/9466"],"dc:language":["English"],"dc:language.iso":["en_US"],"dc:publisher":["University of Alabama Libraries"],"dc:rights":["All rights reserved by the author unless otherwise indicated."],"dc:title":["Small Scale Aeolian Processes and Landform Response"],"dc:type":["thesis","text"]},"updated_at":"2026-07-27T18:44:27Z"}