{"id":{"repo_id":"royalroads","oai_identifier":"oai:null:10613/29459"},"canonical_url":"https://search.dev.ndltd.org/etd/royalroads/oai:null:10613/29459","repository":{"repo_id":"royalroads","name":"Royal Roads University","base_url":"https://www.viurrspace.ca/server/oai/request"},"display":{"title":"Quantifying Uncertainty in Velocity-area Streamflow Measurements Under Non-ideal Conditions","abstract":"The measurement of discharge by the velocity-area method is a commonly used technique but methods for estimating its quantitative uncertainty are rarely studied in non-ideal conditions. Three methods for estimating uncertainty – ISO 748, IVE, and FLAURE – were compared across cross-sections representing both near-ideal and non-ideal conditions along a small, regulated river on Vancouver Island, British Columbia. High-resolution measurements were collected using an acoustic doppler velocimeter with verticals spaced every 0.1 m. Measurements were sub-sampled to investigate the effect of sampling frequency on total uncertainty. All three methods compared well under near-ideal conditions but diverged for sites with non-ideal conditions. Increasing the number of verticals did not improve discharge accuracy for non-ideal conditions. The IVE method was deemed the most conservative and sensitive estimate of total uncertainty in non-ideal conditions when the number of verticals was greater than 20. Further research is required to test how other sampling strategies may improve discharge accuracy for non-ideal conditions, such as increasing the number of velocity measurements at each vertical. Keywords: streamflow, hydrometrics, velocity-area method, flowtracker2, discharge, uncertainty, IVE, FLAURE, ISO","abstract_html":"The measurement of discharge by the velocity-area method is a commonly used technique but methods for estimating its quantitative uncertainty are rarely studied in non-ideal conditions. Three methods for estimating uncertainty – ISO 748, IVE, and FLAURE – were compared across cross-sections representing both near-ideal and non-ideal conditions along a small, regulated river on Vancouver Island, British Columbia. High-resolution measurements were collected using an acoustic doppler velocimeter with verticals spaced every 0.1 m. Measurements were sub-sampled to investigate the effect of sampling frequency on total uncertainty. All three methods compared well under near-ideal conditions but diverged for sites with non-ideal conditions. Increasing the number of verticals did not improve discharge accuracy for non-ideal conditions. The IVE method was deemed the most conservative and sensitive estimate of total uncertainty in non-ideal conditions when the number of verticals was greater than 20. Further research is required to test how other sampling strategies may improve discharge accuracy for non-ideal conditions, such as increasing the number of velocity measurements at each vertical. Keywords: streamflow, hydrometrics, velocity-area method, flowtracker2, discharge, uncertainty, IVE, FLAURE, ISO","abstract_has_math":false,"creators":["Jeffery, Jonathan"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Moore, Dan"],"committee_chairs":[],"committee_members":[],"year":2026,"date_issued":"2026","date_published":"2026","updated_at":"2026-07-27T20:47:44Z","subjects":["School of environment and sustainability"],"languages":["en_US"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://doi.org/10.25316/IR-20986"],"render_values":[{"text":"https://doi.org/10.25316/IR-20986","href":"https://doi.org/10.25316/IR-20986","code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10613/29459","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Moore, Dan"]},{"key":"dc:creator","label":"Author","values":["Jeffery, Jonathan"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2026-05-22T19:03:51Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2026-05-22T19:03:51Z"]},{"key":"dc:date.issued","label":"Date","values":["2026"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["School of environment and sustainability"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en_US"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10613/29459","https://doi.org/10.25316/IR-20986"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["2026"]},{"key":"dc:description.abstract","label":"Abstract","values":["The measurement of discharge by the velocity-area method is a commonly used technique but methods for estimating its quantitative uncertainty are rarely studied in non-ideal conditions. Three methods for estimating uncertainty – ISO 748, IVE, and FLAURE – were compared across cross-sections representing both near-ideal and non-ideal conditions along a small, regulated river on Vancouver Island, British Columbia. High-resolution measurements were collected using an acoustic doppler velocimeter with verticals spaced every 0.1 m. Measurements were sub-sampled to investigate the effect of sampling frequency on total uncertainty. All three methods compared well under near-ideal conditions but diverged for sites with non-ideal conditions. Increasing the number of verticals did not improve discharge accuracy for non-ideal conditions. The IVE method was deemed the most conservative and sensitive estimate of total uncertainty in non-ideal conditions when the number of verticals was greater than 20. Further research is required to test how other sampling strategies may improve discharge accuracy for non-ideal conditions, such as increasing the number of velocity measurements at each vertical. Keywords: streamflow, hydrometrics, velocity-area method, flowtracker2, discharge, uncertainty, IVE, FLAURE, ISO"]},{"key":"dc:title","label":"Title","values":["Quantifying Uncertainty in Velocity-area Streamflow Measurements Under Non-ideal Conditions"]}]}],"canonical_facts":{"dc:contributor.advisor":["Moore, Dan"],"dc:creator":["Jeffery, Jonathan"],"dc:date.accessioned":["2026-05-22T19:03:51Z"],"dc:date.available":["2026-05-22T19:03:51Z"],"dc:date.issued":["2026"],"dc:description":["2026"],"dc:description.abstract":["The measurement of discharge by the velocity-area method is a commonly used technique but methods for estimating its quantitative uncertainty are rarely studied in non-ideal conditions. Three methods for estimating uncertainty – ISO 748, IVE, and FLAURE – were compared across cross-sections representing both near-ideal and non-ideal conditions along a small, regulated river on Vancouver Island, British Columbia. High-resolution measurements were collected using an acoustic doppler velocimeter with verticals spaced every 0.1 m. Measurements were sub-sampled to investigate the effect of sampling frequency on total uncertainty. All three methods compared well under near-ideal conditions but diverged for sites with non-ideal conditions. Increasing the number of verticals did not improve discharge accuracy for non-ideal conditions. The IVE method was deemed the most conservative and sensitive estimate of total uncertainty in non-ideal conditions when the number of verticals was greater than 20. Further research is required to test how other sampling strategies may improve discharge accuracy for non-ideal conditions, such as increasing the number of velocity measurements at each vertical. Keywords: streamflow, hydrometrics, velocity-area method, flowtracker2, discharge, uncertainty, IVE, FLAURE, ISO"],"dc:identifier.uri":["https://hdl.handle.net/10613/29459","https://doi.org/10.25316/IR-20986"],"dc:language.iso":["en_US"],"dc:subject":["School of environment and sustainability"],"dc:title":["Quantifying Uncertainty in Velocity-area Streamflow Measurements Under Non-ideal Conditions"],"dc:type":["Thesis"]},"updated_at":"2026-07-27T20:47:44Z"}