Date of Completion


Embargo Period



Stream Visual Assessment; Geomorphic Units; Spatiotemporal Delineation; Human Perception

Major Advisor

Nathaniel Trumbull

Associate Advisor

Timothy Byrne

Associate Advisor

Anji Seth

Associate Advisor

Jason Vokoun

Field of Study



Doctor of Philosophy

Open Access

Open Access


The utility of human visual assessments to stream geomorphic unit delineation as part of project work inception has been established in the literature. However, certain issues arise. The impact of flow stage variation on stream geomorphic unit (SGU) distribution is not well known and the relatively short time that is spent conducting a visual assessment is not adequate to sufficiently understand the stream spatiotemporal dynamic. Also, critical assumptions regarding personal proficiency with visual assessments are embraced, yet often go untested. Even more, various disciplines are discordant in the way they identify and define stream units – interpersonal differences lead to very different SGU delineations. This dissertation addresses the aforementioned difficulties by providing an innovative spatiotemporal mechanism that explores stream geomorphic unit dynamics with discharge, resolving conflicting definitions, integrating a hierarchical workflow for streams projects, building a statistical device to realize both individual deficiencies and proficiencies with unit delineation, and creating a robust delineation error prediction technique. Despite the appeal of quick assessments, thorough understanding of stream and self are requisite to an inclusive technique. This research pushed the boundaries of understanding more fully the human dimension of stream geomorphic unit visual assessment.