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Full-Text Articles in Physical Sciences and Mathematics

Detecting Change In Rainstorm Properties From 1977-2016 And Associated Future Flood Risks In Portland, Oregon, Alexis Kirsten Cooley Sep 2017

Detecting Change In Rainstorm Properties From 1977-2016 And Associated Future Flood Risks In Portland, Oregon, Alexis Kirsten Cooley

Dissertations and Theses

In response to increased greenhouse gases and global temperatures, changes to the hydrologic cycle are projected to occur and new precipitation characteristics are expected to emerge. The study of these characteristics is facilitated by common indices to measure precipitation and temperature developed by the Expert Team on Climate Change Detection and Indices (ETCCDI). These indices can be used to describe the likely consequences of climate change such as increased daily precipitation intensity (SDII) and heavier rainfall events (R95p). This study calculates a subset of these indices from observed and modelled precipitation data in Portland, Oregon. Five rainfall gages from a …


Analyzing Dam Feasibility In The Willamette River Watershed, Alexander Cameron Nagel Jun 2017

Analyzing Dam Feasibility In The Willamette River Watershed, Alexander Cameron Nagel

Dissertations and Theses

This study conducts a dam-scale cost versus benefit analysis in order to explore the feasibility of each the 13 U.S. Army Corps of Engineers (USACE) commissioned dams in Oregon’s Willamette River network. Constructed between 1941 and 1969, these structures function in collaboration to comprise the Willamette River Basin Reservoir System (WRBRS). The motivation for this project derives from a growing awareness of the biophysical impacts that dam structures can have on riparian habitats. This project compares each of the 13 dams being assessed, to prioritize their level of utility within the system. The study takes the metrics from the top …


Effects Of Spatially Distributed Stream Power On Check Dam Function In Small Upland Watersheds: A Case Study Of The Upper Laja Watershed, Guanajuato, Mexico, Zachary Andrew Herzfeld Jan 2017

Effects Of Spatially Distributed Stream Power On Check Dam Function In Small Upland Watersheds: A Case Study Of The Upper Laja Watershed, Guanajuato, Mexico, Zachary Andrew Herzfeld

Dissertations and Theses

Watershed restoration comes in a variety of forms depending on which set of problems are sought to be remedied. Severe soil erosion, in the form of gullying and/or headcutting, can be mitigated through constructing check dams in well-selected locations. This practice has been used throughout the upland subwatersheds within the Upper Laja River watershed in Guanajuato, México. The present study employed Wolman pebble counts to systematically assess the effectiveness of 21 check dams located near the city of San Miguel de Allende. Particle size distributions taken directly downstream and upstream of each check dam were differentiated, aggregated and compared--with the …