Building in flow

Abstract

This dissertation features one experimental study, field study, and literature review to address building in flow. We start with the small-scale observations of a localized logjam. Chapter one is to understand the structural basis of quasi-2D jamming in flow. The questions are 1) under what conditions do jams form, and 2) is there a structural parameter that characterizes the degree of a) ordered, b) disordered, or c) arched. From here, this work takes a larger-scale approach to observing building in a localized habitat. Chapter two asks how a living organism, the North American beaver, can carry a similar process to jamming in constructing their dams. A beaver must source terrestrial materials to build aquatic dams and navigate complex terrestrial and aquatic topography over large scales. Using drone footage, combined with GIS analysis and in-field flow measurements of the streams, this work characterized under what conditions building is initiated and terminated by tracking trail formation and estimating an effective Darcy permeability associated with the dimensions of the dam. From this work, an initial generalization can be made by connecting the structure to the behavioral aspects of the builder. Chapter three contextualizes the field study by taking a broad overview of aquatic architects across the natural world by compiling a dataset based on extensive sampling of literature, including 1)the biology of the builder, 2) the morphology of the structure, 3) habitat characteristics of where an architecture resides, 4) material properties, and 5) the hydrodynamic characteristics of the environment. Doing so enabled an understanding of structure size concerning builder size, material usage, and structure complexity. This work further characterizes the structures in terms of Effective strength, Reynold's number, Froude number, the Shield parameter, and the aspect ratio of the structure. Chapter 4 is a brief narrative on the ethics and considerations of conducting fieldwork within Indigenous communities. Chapter 5 looks to future building applications in flow.