Completed

Classification of a Desert Urban Landscape Using Multi-spectral Analysis

Jerry D Davis — Sun, 17 Aug 2025 18:28:17 +0000

Thesis

Proposal for Culminating Experience Submitted

2023-09-30

Michael Martin

Year

2024

Defense Date

12-12-2024

Committee

Leonhard Blesius

XiaoHang Liu

Posted PDF

Status

Completed

Pore-scale dual-domain flow and temporal variability in recharge, High Plains Aquifer, USA

Alaina Ross — Tue, 22 Jul 2025 22:53:34 +0000

Thesis

Brent Corbin Everett

Year

2011

Abstract

Between 2006 and 2010, heat dissipation probes monitored real-time matric potential at various depths in the vadose zone beneath two semiarid natural grassland sites within the High Plains aquifer. Monitoring results indicate 1) a downward potential for water movement, 2) at least 4 wetting fronts that rapidly propagated to previously unobserved depths (7.3 to 23.0 m below land surface), and 3) rapid water fluxes (0.9 to 6.8 mm/day) that likely resulted in recharge events during the period of observation. Measured water fluxes are orders of magnitude greater than previous estimates using convention tracer-based techniques that provide average water fluxes over decadal to millennial timescales. The rapid water fluxes are likely controlled by pore-scale dualdomain flow. Using observations from this study, I propose a new conceptual model of water flux in the vadose zone beneath natural grasslands in semiarid climates. The model conceptualizes monotonically decreasing total potential, and deep and rapid water movement that can result in episodic recharge events. The movement of water on daily to monthly timescales has important implications for the enhanced mobilization of some fraction of surface-derived contaminants in the vadose zone to groundwater. Most notably, interpretations of the observations and reported water fluxes from this study may account for the inconsistencies between observed groundwater chemistry and previously estimated chemical fluxes in the vadose zone of the High Plains aquifer.

Full Text

AS362011GEOLE94V1.pdf4.31 MB

Posted PDF

Yes

Status

Completed

Citation

https://scholarworks.calstate.edu/concern/theses/5425kc219

Damping characteristics of wave propagation across the muddy Louisiana shelf

Alaina Ross — Thu, 17 Jul 2025 19:25:40 +0000

Thesis

Anita Cathrine Engelstad

Year

2011

Abstract

To improve the understanding of the effect of a muddy seafloor on wave dynamics, a new data set, collected on the muddy Louisiana coast in the spring of 2008, is analyzed. Waves were observed for two months at 32 locations along a 25 km transect between 13- and 2-m water depth. To investigate the effects of mud on the nearshore wave energy balance, the SWAN wave model was used to hindcast the observational period, using a standard JONSWAP bottom friction term for wave-bottom interaction to represent wave propagation across a sandy shelf. The findings show that the interaction between mud and waves is episodic. We identify two types of wave-mud damping events, where either 1) the damping occurs in the energetic ranges of the spectrum, generally stronger at lower frequencies, or 2) wave growth is suppressed during times of heightened sediment concentrations throughout the water column. Our observations suggest that currents play an important role in the resuspension of sediments.

Tim Janssen

Newell (Toby) Garfield

Thomas H.C. Herbers

Full Text

AS362011GEOLE54.pdf3 MB

Posted PDF

Yes

Status

Completed

Quantitative linkages between watershed conditions and mainstem channel characteristics in Lagunitas Creek, Northern California

Alaina Ross — Thu, 17 Jul 2025 19:21:58 +0000

Thesis

James Alan Chayka

Year

2011

Abstract

The Lagunitas Creek watershed provides critical habitat to endangered and threatened fish populations. Although much research has been conducted on the relationship between sediment particle size and habitat quality, it is not well known how watershed conditions may affect the bed texture variability along mainstem channels. I explore the relationship between watershed conditions and channel bed texture through a geomorphic landscape unit (GLU) framework which analyzes the spatial distribution of rock type, land cover, and surface gradients for selected sub water sheds. I found that channel slopes do not appear to correlate with variations in bed texture, but it is not immediately apparent that differences in subwatersheds can explain this variability. Individual subwatershed attributes—instead of combined GLUs—may be more appropriate for predicting bed texture. I suggest an adjusted GLU approach that is more sensitive to variability within each attribute category.

Committee

Leonard Sklar

Karen Grove

Ray Pestrong

Full Text

AS362011GEOLC439.pdf3.83 MB

Posted PDF

Yes

Status

Completed

Citation

https://scholarworks.calstate.edu/concern/theses/g445cg03g

Fluid controlled metamorphism of eclogitic pseudotachylite-bearing shear zones, Flakstadøy, northern Norway

Alaina Ross — Thu, 17 Jul 2025 19:16:20 +0000

Thesis

Deborah Joy Shulman

Year

2012

Abstract

The Lofoten Islands in northern Norway represent the lower crust in the Baltica- Laurentia collision during the Caledonian Orogeny -460 Ma. The island of Flakstadoy consists o f -1.8 Ga granulite-facies gneisses and AMCG units cut by discrete Caledonian shear zones, some containing pseudotachylite veins. A combination of petrography, mineral chemistry, and electron backscatter diffraction analyses show a spatial relationship between pseudotachylite formation, shear zone development, fluid infiltration, and metamorphism. Microfractures and backscatter imaging indicate that pseudotachylite-forming processes seismically shattered the rocks, reducing grain sizes and opening fluid pathways. Evidence of eclogite-facies metamorphism in omphacite and/or albite-diopside symplectite is found exclusively in the shear zones. A strong amphibolite-facies overprint in the shear zones replaced eclogite with amphibolite; a strong alignment of amphibole 0 0 1 parallel to the shear zone fabric indicates fluid availability during shearing. A lack of amphibole growth in the host rock indicates they remained effectively dry. I propose that co-seismic pseudotachylite formation opened fluid pathways in an otherwise effectively dry, impermeable granulitic crust. The advection of fluids led to localized strain and eclogite-facies metamorphism in otherwise metastable granulites. Permeability was maintained through localized strain during exhumation leading to a nearly complete amphibolite-facies overprint in the shear zones.

Committee

Mary Leech

Karen Grove

Christopher Gerbi

Full Text

AS362012GEOLS58.pdf9.63 MB

Posted PDF

Yes

Status

Completed

Citation

https://scholarworks.calstate.edu/concern/theses/mg74qn69b

Establishing background arsenic in soil of the urbanized San Francisco Bay region

Alaina Ross — Thu, 17 Jul 2025 19:03:12 +0000

Thesis

Dylan Jacques Duvergé

Year

2011

Abstract

Soil analysis data within the nine-county San Francisco Bay Area was compiled from the State Water Quality Control Board's Geotracker online database to determine the background levels and variability of arsenic concentrations across four Quaternary geologic units. Arsenic analyses of 1,454 soil samples across 77 sites were screened from Geotracker for inclusion in a JMP 7.0 database. Mean arsenic concentrations within Holocene alluvium (5.10 mg/kg) were determined to be statistically greater than those within Pleistocene alluvium (3.65 mg/kg) and "other" Quaternary units (3.30 mg/kg); and no significant relationship was found between arsenic concentrations and sampling depth. The proposed upper estimate for background arsenic (99th percentile) within undifferentiated flatland soils of the study area—11.00 mg/kg—is markedly lower than commonly cited sources in the literature. These findings present the first regional estimates of background arsenic concentrations in the San Francisco Bay Area.

Committee

Jason Gurdak

Jerry Davis

Mary Rose Cassa

Full Text

AS362011GEOLD88.pdf4.43 MB

Posted PDF

Yes

Status

Completed

Citation

https://scholarworks.calstate.edu/concern/theses/zs25xb251

Geomorphic controls on spatial distributions of cobbles and boulders in stream-channel networks

Alaina Ross — Thu, 17 Jul 2025 18:59:49 +0000

Thesis

Eric Donaldson

Year

2011

Abstract

Cobbles and boulders (CoBo) in stream channels provide overwintering habitat for juvenile steelhead trout (Oncorhynchus mykiss). Lack of overwintering habitat may be a key limiting factor causing dwindling steelhead populations. Here, I develop a model for predicting the spatial distribution of CoBo in Pescadero Creek, San Mateo County, northern California, which could be used to estimate the watershed-scale extent of overwintering habitat. The model is based on the theoretical expectations that (1) bed sediment is at threshold of motion at bankfull discharge, (2) debris flows deliver large material to predictable locations in stream channel networks, (3) shallow landsliding is a primary source for debris flows, and (4) that durable source bedrock is necessary for CoBo to occur. I develop and test the model with a combination of field reconnaissance, laboratory rock strength testing, and GIS analysis of the channel network and upstream shallow landsliding potential and rock type. The model correctly predicts the occurrence or lack of CoBo at 90% of the field-verified sites using criteria for channel slope, drainage area, and upstream extent of either hillslope instability or durable bedrock. From measurements of refugia density in two reaches, I estimate that CoBo can support 0.5 fish/m2 for juvenile steelhead.

Committee

Leonard Sklar

Jason Gurdak

Tim Janssen

Full Text

AS362011GEOLD66.pdf2.32 MB

Posted PDF

Yes

Status

Completed

Citation

https://scholarworks.calstate.edu/concern/theses/47429b87s

A comprehensive survey of buoyancy and shear parameters for California tornadoes: 1951-2011

Alaina Ross — Thu, 17 Jul 2025 18:54:25 +0000

Thesis

Christopher J. Stumpf

Year

2012

Abstract

The buoyancy and shear environments for 391 tornado events in California from 1951-2011 were evaluated on the basis of an analyses of proximity soundings and hodographs. The events were stratified into F0, FI, and F2/F3 categories or bins. The 0-1 km above ground level (AGL) Absolute Value Shear (ABVSHR), which is similar to positive shear [as defined in Lipari (2000)], was found to be a statistically significant discriminator between the bins, with increasing values of ABVSHR associated with the higher intensity tornadoes. Approximately 65% of the tornado events exhibited low level and deep layer shear values in the ranges consistent with mesocyclone formation in the parent thunderstorm. Shear values for F0 and FI tornado events occurring before 1980 suggest that there was a systematic misrating of the tornadoes, with most probably assigned too high an F-rating. Case studies of two of the more damaging tornadic events (associated with the Sunnyvale F2 and Los Angeles F2) early in the California tornado record showed that both occurred in shear environments favoring tornadic supercells. Based upon an evaluation of documentary evidence, the author recommends that the Sunnyvale event should be re-rated to F3 and three additional tornadoes occurring on the same day should be added to the database. The Los Angeles tornado event was probably accurately rated.

Committee

John Monteverdi

Oswaldo Garcia

Dave Dempsey

Full Text

AS362012GEOLS78.pdf9.82 MB

Posted PDF

Yes

Status

Completed

Citation

https://scholarworks.calstate.edu/concern/theses/6108vd030

Geophysical evidence for quaternary deformation within the offshore San Andreas Fault System, Northern California

Alaina Ross — Thu, 17 Jul 2025 18:50:20 +0000

Thesis

Brian Andrew Stozek

Year

2012

Abstract

Offshore multichannel and mini-sparker seismic reflection profiles collected north of San Francisco indicate varying tectono-stratigraphic conditions since the Late Miocene. Near the Point Reyes Peninsula headland, Miocene units have been vertically offset at least 2 km on the Point Reyes fault (PRF); deformation began during the Late Miocene, probably in response to a change in relative plate motions. North of the peninsula, multiple Quaternary sequences formed above a subsiding Plio-Pleistocene unconformity (PPU) during eustatic sea-level fluctuations. The mechanism for subsidence may be related, in part, to isostatic loading from thick Pleistocene deposits derived from the Russian River. West of the Gualala Block, preserved sequences have been folded, probably starting ~500 ka, by transpressional structures associated with the Gualala fault. South and adjacent to the headland, few Pleistocene sediments are preserved. The PPU and overlying Holocene deposits are undeformed, suggesting that the PRF has become increasingly inactive since the Middle Pleistocene and that its hazard potential in current fault and tsunami hazard models should be reduced.

Committee

Karen Grove

John Caskey

Holly Ryan

Full Text

AS362012GEOLS76.pdf11.59 MB

Posted PDF

Yes

Status

Completed

Citation

https://scholarworks.calstate.edu/concern/theses/m039k649s

Recharge beneath low impact development and the effects of climate variability

Alaina Ross — Thu, 17 Jul 2025 18:46:27 +0000

Thesis

Michelle E. Newcomer

Year

2012

Abstract

Groundwater resources in urban, coastal environments are highly vulnerable to human pressures and climate variability. Impervious surfaces often overflow sewage systems, prevent infiltration, and reduce recharge to aquifers. To mitigate these effects, cities worldwide are adopting Low Impact Development (LID) approaches that are hypothesized to increase infiltration and recharge rates to aquifers. The effects of LID on recharge rates are unknown, particularly in response to interannual variability of the El Nino Southern Oscillation (ENSO). Results from this study indicate recharge rates are enhanced by one order of magnitude beneath LID compared with an irrigated grass lawn and are greater during El Nino years. Recharge rates are projected to increase by 100 mm/year beneath LID and increase 6.9% under forecasted El Nino years as compared to current El Nino years. This work highlights the benefits of LID to capture and store stormwater during El Nino years, which can help urban planners manage above average water volumes introduced from climate variability.

Committee

Jason Gurdak

Leonard Sklar

Rachel Kraai

Full Text

AS362012GEOLN49.pdf5.14 MB

Posted PDF

Yes

Status

Completed

Citation

https://scholarworks.calstate.edu/concern/theses/4q77ft10q