Physical Sciences and Mathematics Commons^™

Resurgence Of An Apex Marine Predator And The Decline In Prey Body Size, Jan Ohlberger, Daniel E. Schindler, Eric J. Ward, Timothy E. Walsworth, Timothy E. Essington

Watershed Sciences Faculty Publications

In light of recent recoveries of marine mammal populations worldwide and heightened concern about their impacts on marine food webs and global fisheries, it has become increasingly important to understand the potential impacts of large marine mammal predators on prey populations and their life-history traits. In coastal waters of the northeast Pacific Ocean, marine mammals have increased in abundance over the past 40 to 50 y, including fish-eating killer whales that feed primarily on Chinook salmon. Chinook salmon, a species of high cultural and economic value, have exhibited marked declines in average size and age throughout most of their North …

Beavers Alter Stream Macroinvertebrate Communities In Northeastern Utah, Susan E. Washko, Brett B. Roper, Trisha Brooke Atwood

Watershed Sciences Faculty Publications

1. Understanding changes in macroinvertebrate communities is important because they play a large role in stream ecosystem functioning, and they are an important food resource for fish. Beaver‐induced changes to stream morphology could alter macroinvertebrate communities, which in turn could affect food webs and ecosystem function. However, studies investigating the effects of North American beaver activities on macroinvertebrates are rare in the inter‐mountain west, an area with high potential for beaver‐assisted restoration.
2. The aim of this study was to quantify differences in the macroinvertebrate community between unaltered segments of streams and within beaver ponds in north‐eastern Utah, U.S.A. We assessed macroinvertebrate …

Assessing Beaver Dam Dynamics In The Logan-Little Bear Watershed, Connor Penrod

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

This paper seeks to address a knowledge gap concerning how flood events impact beaver dams over time. To address this gap, I took four time-snapshots of beaver dams, mapping them across the Utah portion of the Logan-Little Bear watershed, from 2009 to 2016 to bookend a large flood event in 2011. I assessed dam status (intact, breached, or blown out) for each dam mapped to assess the impact of the large spring runoff on the dam status. Assessing dam status over time allowed me to assess the change in condition over time, from before to several years after, while also …

Evaluation Of Stream Bank Restoration To Improve Water Quality In A Semi-Arid Stream, Johnathan Neenan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Human watershed activities such as converting land cover to agriculture and livestock grazing have negatively impacted stream water quality worldwide. One such case is Utah’s Upper Sevier River where a loss of woody bank vegetation (reduced shading) and accelerated bank erosion (increased fine sediment inputs) has led to increased stream temperature and water turbidity. As a result, the state of Utah sought to improve water quality conditions using streambank restoration. While commonly recommended and performed, the effectiveness of this sort of restoration has rarely been quantified. Here, I evaluated a restored reach of the Upper Sevier River near Hatch, UT …

Wildfire In The West: An Initial Analysis Of Wildfire Impacts On Hydrology And Riverbed Grain Size In Relation To Salmonid Habitat, Natalie J. Gillard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Historically wildfires have been beneficial to forests, however, human developments have encroached on forests when wildfire was artificially suppressed by federal and state agencies. The area burned by wildfire each year has increased twenty-fold in the past three decades. Large, high severity fires pose increased threats to human and aquatic communities within and downstream of the burned area due to post-wildfire effects on flooding and sedimentation. We need to understand the impacts of wildfires to be able to mitigate their damages and to recognize their potential benefits. This research addresses the questions: 1) Do wildfires impact rural and urban economies …

Mapping Valley Bottom Confinement At The Network Scale, Gary R. O'Brien, Joseph Michael Wheaton, Kirstie Fryirs, William W. Macfarlane, Gary Brierley, Kelly Whitehead, Jordan T. Gilbert, Carol Volk

Watershed Sciences Faculty Publications

In this article, we demonstrate the application of a continuous confinement metric across entire river networks. Confinement is a useful metric for characterizing and discriminating valley setting. At the reach scale, valley bottom confinement is measured and quantified as the ratio of the length of channel confined on either bank by a confining margin divided by the reach length. The valley bottom is occupied by the contemporary floodplain and/or its channel(s); confining margins can be any landform or feature that makes up the valley bottom margin, such as bedrock hillslopes, terraces, fans, or anthropogenic features such as stopbanks or constructed …

Examination Of The Climate Factors That Reduced Wheat Yield In Northwest India During The 2000s, Avik Mukherjee, Shih-Yu (Simon) Wang, Parichart Promchote

Plants, Soils, and Climate Faculty Publications

In India, a significant reduction of wheat yield would cause a widespread impact on food security for 1.35 billion people. The two highest wheat producing states, Punjab and Haryana in northern India, experienced a prolonged period of anomalously low wheat yield during 2002–2010. The extent of climate variability and change in influencing this prolonged reduction in wheat yield was examined. Daily air temperature (T_max and T_ave) was used to calculate the number of days above optimum temperature and growing degree days (GDD) anomaly. Two drought indices, the standard precipitation and evapotranspiration index and the radiation-based precipitation index, …

Introductory R For Water Resources - Fall 2019 - University Of North Carolina At Chapel Hill, David Gorelick, Gregory Characklis

All ECSTATIC Materials

This is all course material for R for Researchers, a one-credit course taught at UNC Chapel Hill in Fall 2019 to introduce upperclassmen and graduate students to the R programming language and apply learned skills in basic water resources applications, as well as other (semi-related) topics of interest to students.

Lecture notes were distributed before (as a subset of full lecture notes) and after lectures, and lectures involved collaborative coding exercises with students in class without any powerpoint material. Course material here includes:

Syllabus: rough schedule and description of lectures

Lectures: pdf lecture notes with embedded code, including …