Quantifying Human Impacts on River Bar Morphology Using Digital Photogrammetry

Historically, the study of fluvial geomorphology has been dominated by the field method of surveying using a level and surveying rod. Beginning in the 1980s, the use of ground based and aerial LiDAR increased in popularity as a surveying method. However, LIDAR is expensive and requires significant training to operate. In recent years there has been an increase in the applicability of digital photogrammetry in the field of fluvial geomorphology. Lower costs, streamlined training and an increased accuracy all make digital photogrammetry a promising tool for the field geomorphologist. A study of the morphologic changes of four river bars on the Browns Canyon section of the Arkansas River, Colorado is used to explore the potential of digital photogrammetry by attempting to quantify the impacts of recreation river users on bar morphology. By creating high resolution digital elevation models (DEMs) at time intervals from 24 hours to several days, DEMs of difference (DoDs) were created and analyzed using the open-source 3D data processing software CloudCompare. DoDs were correlated with historical, daily commercial river user data to derive a relationship. Verification concerning the validity of CloudCompare was done using a simple experiment simulating erosion and deposition of a known volume of material

Photography and field data used for hydrogeomorphic analysis of the Rogue River in southwest Oregon, USA

Contains README file, and data in three formats: georeferenced orthophotographs, videos and csv files.This data set contains three data types. The majority of the data here are the individual photographs used to build the Structure-from-Motion models of the gravel bars used in the study. The photos for each gravel bar are saved in a separate folder. In addition, there are a series of folders which contain the imagery used to produce maps of water surface roughness. There is also tabular data that was generated from the single-beam echo sounder which recorded depth.This data was funded a Doctoral Dissertation Research Improvement grant by the National Science Foundation (#1734840). Additional support came from the American Society for Photogrammetry and Remote Sensing and the Department of Geography at the University of Oregon

Lateral Channel Confinement, Tributaries, and Their Impact on Channel Morphology

Humans have had a ubiquitous influence on fluvial systems worldwide (Wohl, 2013). Landscape modifications such as lateral channel confinement and flow modifications frequently result in changes to channel morphology including width, depth, channel slope, unit stream power, and particle size distributions (PSD). Morphologic changes can be directly measured, but may also be reflected in the patterns of water surface roughness. This research builds on downstream hydraulic geometry (Leopold and Maddock, 1953) and the sediment links concept (Rice, 1998) to examine anthropogenic and natural controls on channel form across spatial scales. It also develops a method for mapping water surfaces with the same resolution we measure channel form. This research examines how anthropogenic and natural mechanisms control channel form along a 200-kilometer section of the Rogue River in Southern Oregon. I use a combination of remote sensing and field data to create a hyperscale data set containing width, slope and depth data. I use Structure-from-Motion to create particle size distributions for all exposed gravel bars in the study area. With these data I conducted a number of non-parametric statistical analysis to examine how natural and anthropogenic forces influence longitudinal trends in channel morphology. v I find that the Rogue River is a highly heterogenous river. At basin-wide scales it does not conform to our traditional views of downstream hydraulic geometry. At smaller spatial scales, the role of local geology triggers an alteration between the commonly observed trends in downstream hydraulic geometry and trends that do not match theory. At scales of 10s of kilometers anthropogenic controls on channel form trigger statistically significant modification of channel form as compared to natural channel reaches. Tributary and non-tributary sediment sources do not consistently result in a statically significant change to channel morphology. However, evidence of persistent delivery of sediment through alluvial and colluvial processes does appear to play an important role in channel morphology. This research supports the claim that intensive and extensive data collection of fluvial systems will further out understanding of how external and autogenic processes control channel morphology; allowing the combination and improvement of current theory which exist and distinct spatial scales