Digital Commons Network^™

The Formation Of Glacier Dirt Cones, Ryan M. Strickland, Matthew D. Covington

Geosciences Faculty Publications and Presentations

Glacier dirt cones are meter-scale cones of ice covered with sediment and rock. The cones develop through a process known as differential melt, whereby ice underlying thick debris melts more slowly than bare ice. We report observations of dirt cones on the Kuskulana Glacier, Alaska and develop a model that simulates the growth of dirt cones from debris-filled pits in the ice. With this model, we vary ice melt rates, hillslope debris diffusion rates and pit geometry. Cone heights scale with the square root of debris volume and growth occurs in three distinct stages: emergence, flux-controlled growth and melt-controlled growth. …

Community Land Governance In Liberia: Implications For Tenure Security And Land Concessions, Julia R. Entwistle, Hanson Nyantakyi-Frimpong

Geography and the Environment: Faculty Scholarship

Throughout rural Africa, the intersection of customary traditions and statutory governance has often led to overlapping jurisdictions and conflicts over community land rights. In Liberia, this dynamic is particularly evident in the rise of commercial land concessions. This article examines the Liberian government’s approach to community land rights and its impacts on land tenure security, especially in the context of these concessions. This study employs a discourse analysis of Liberian land use policies alongside qualitative data from in-depth interviews with community members living near large-scale plantations. Despite historical erosion of community land rights, Liberian communities have adapted statutory frameworks to …

Prenatal Exposure To Pm2.5 Concentration And Risk Of Preterm Birth In New Mexico; A Seasonal Pattern And Spatio-Temporal Modeling., Onyedikachi J. Okeke

Mathematics & Statistics ETDs

This study investigates the association between prenatal PM2.5 exposure and preterm birth risk in New Mexico (2014–2021). Using descriptive statistics, time series models, and spatial analyses, findings show an average preterm birth rate of 14.87 per 1,000 live births, with moderate correlation (r = 0.727) between PM2.5 levels and very preterm births. While traditional models revealed no significant global effect, spatial methods such as Geographically Weighted Regression (GWR) and Multiscale GWR uncovered strong spatial heterogeneity. PM2.5 effects varied by county (coefficients: -0.00154 to 0.00150), with clustering evident in 2018–2019 (Moran’s I = 0.155–0.174). Results highlight the limitations of global models …

Seasonal Effects Of Plant Functional Groups On Molecular Biogeochemistry Of Dissolved Organic Matter In Porewater Of A Poor Fen, Zhimin Song, Maryam Khaksari, Erik A. Lilleskov, Evan Kane, Paul V. Doskey

Michigan Tech Publications

Climate change may transform peatlands from net carbon (C) sinks to C sources, which could result in a positive feedback to global warming. Warmer temperatures might lower water tables, increase the abundance of shrubs, slow Sphagnum and sedge growth and further accelerate the decomposition of dissolved organic matter (DOM) with a concomitant release of C from the surface. Studies in which vascular plant functional groups (PFGs) in peatlands have been manipulated to mimic the potential effects of a warming climate on DOM are scarce. In the subject study, seasonal effects of PFGs on the molecular composition of DOM of peat …

Perencanaan Bauran Pembangkit Listrik Energi Terbarukan Di Indonesia: Pendekatan Optimasi Program Linier Berbasis Wilayah, Annisa Garmaisa, Uka Wikarya

Jurnal Kebijakan Ekonomi

Indonesia has renewable energy potential spread across various islands. However, limited interconnection between regions is an obstacle to energy distribution. The purpose of this study is to analyze the planning of renewable energy (RE) power plants covering eight types: Geothermal Power Plants (PLTP), Solar Power Plants (PLTS), Wind Power Plants (PLTB), Biomass Power Plants (PLTBm), Biogas Power Plants (PLTBg), and Waste Power Plants (PLTSa). The analysis was conducted in four main system regions in Indonesia, namely Java-Bali, Sumatra, Kalimantan, and Sulawesi, which are currently not interconnected. The study is based on the availability of renewable energy potential, production forecasts, and …

Development And Application Of Self-Supervised Machine Learning For Smoke Plume And Active Fire Identification From The Fire Influence On Regional To Global Environments And Air Quality Datasets, Nicholas Lahaye, Anastasija Easley, Kyongsik Yun, Hugo Lee, Erik Linstead, Michael J. Garay, Olga V. Kalashnikova

Engineering Faculty Articles and Research

Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) was a field campaign aimed at better understanding the impact of wildfires and agricultural fires on air quality and climate. The FIREX-AQ campaign took place in August 2019 and involved two aircraft and multiple coordinated satellite observations. This study applied and evaluated a self-supervised machine learning (ML) method for the active fire and smoke plume identification and tracking in the satellite and sub-orbital remote sensing datasets collected during the campaign. Our unique methodology combines remote sensing observations with different spatial and spectral resolutions. With as much as a 10% …

Changes In The Western Flank Of The North Atlantic Subtropical High Since 1140 Ce: Extremes, Drivers, And Hydroclimatic Patterns, Joshua C. Bregy, Justin T. Maxwell, Scott M. Robeson, Grant L. Harley, Valerie Trouet

Publications

Summer circulation and moisture patterns in the Southeast United States are controlled by the position of the North Atlantic subtropical high. In a warming climate, the subtropical high is projected to strengthen and expand west, but there remains uncertainty regarding its variability and linkages to natural drivers. Here, we use a tree-ring network across the Southeast United States to reconstruct the relative intensity of the pressure gradient across the subtropical high’s western flank over the past 870 years. Variations in the flank’s position and the pressure gradient have been a major driver of the hydroclimate—including creating a Southeast-Caribbean moisture dipole—since …

Climate Change Threatens Water Resources For Major Field Crops In The Serbian Danube River Basin By The Mid-21st Century, Jamshid Jalali, Nishan Bhattarai, Jillian Greene, Tao Liu, Oskar Marko, Mirjana Radulović, Molly Sears, Sean A. Woznicki

Open Access Publishing Support Funded Articles

Study region: Serbian Danube River Basin

Study focus: As climate change makes weather patterns more erratic, water supply for agriculture is becoming increasingly uncertain. This is concerning in the Serbian Danube River Basin, where crops are mainly rainfed and the growing season is becoming warmer and drier. Assessing the balance between future agricultural water demand and availability in a changing climate is critical to address agricultural water scarcity. To understand how changing climate will affect water availability during 2041–2070, we used the Soil and Water Assessment Tool+ hydrological model with field-scale crop rotations and irrigated extent data and forced with …

A Comprehensive Assessment Approach For Multiscale Regional Economic Development: Fusion Modeling Of Nighttime Lights And Openstreetmap Data, Zhe Wang, Jianghua Zheng, Chuqiao Han, Binbin Lu, Danlin Yu, Juan Yang, Linzhi Han

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Assessing regional economic development is key for advancing towards the Sustainable Development Goals and ensuring sustainable societal progress. Traditional evaluation methods focus on basic economic metrics like population and capital, which may not fully reflect the complexities of economic activities. Nighttime light (NTL) has been validated as an alternative indicator for regional economic development, yet limitations persist in its evaluation. This study integrates OpenStreetMap (OSM) data and NTL data, providing a novel data integration approach for evaluating economic development. The study uses mainland of China as a case, applying ordinary least squares (OLS) and geographically weighted regression (GWR) to evaluate …

‬ ‭ Spiritual Geographies And Living Ritual:‬ ‭ Misali Island’S Caves In Swahili Religious Life In Zanzibar, Everett Gordon

Tanzania-Zanzibar: Coastal Ecology and Natural Resource Management

Caves along the East African Swahili coast are more than geological formations—they are spiritual landscapes where the boundaries between visible and invisible worlds collapse. This paper explores the ritual and religious significance of three caves on Misali Island, a small coral rag island off the coast of Pemba in the Zanzibar Archipelago. Drawing on vegetation surveys and three weeks of ethnographic fieldwork, including interviews with local fishermen, waganga (healers), and marine rangers, this study investigates how these caves serve as sites of prayer, healing, and spirit veneration. It argues that the practices performed within and around these caves exemplify the …

Agricultural Innovation To Climate Change In Northwest Pemba Island, Margaret Horn

Tanzania-Zanzibar: Coastal Ecology and Natural Resource Management

This study investigates how climate change is reshaping agriculture and food security on Pemba Island, Zanzibar, a region historically known as “The Green Island” for its rich biodiversity and agricultural productivity. Through semi-structured interviews with 11 local farmers and extended participant observation at the farm of government official Amour Juma Mohammed, the research reveals that increasingly erratic rainfall, rising temperatures, and prolonged droughts are disrupting traditional planting cycles and reducing crop yields. Farmers report the near disappearance of the vuli rainy season and increasingly severe weather during masika, leading to both water scarcity and crop damage. In response, many have …

Geochronology Of Senèze, Eric Delson, Sébastien Nomade, Sevket Sen, Evelyne Debard, Jean-François Pastre, Jean-Jacques Bahain, Qingfeng Shao, Christophe Falguères

Publications and Research

The age of the Senèze mammalian fauna has been discussed since it was first reported in 1892. 40Ar/39Ar ages reported by Nomade et al. (2014) and recalculated here to agree with current standards placed the deposits between 2.20 and 2.07 Ma. Paleomagnetic data collected in 2001 and 2004 help to narrow the age range, especially of the levels yielding fossils in 2001–2006. In the western sector, fossils can be securely dated between 2.10 and 2.08 Ma, while in the southeastern sector, they are slightly older, between 2.20 and 2.18 Ma. Senèze is one of the few later Cenozoic European sites …

Enhancing Remote Sensing Imagery Temporal Resolution Using Starfm Data Fusion Approach For Improved Land Surface Monitoring, Ahmadreza Pourghodrat

School of Computing: Dissertations, Theses, and Student Research

High-resolution remote sensing imagery plays a critical role in various domains, such as farm-level agricultural operations, environmental monitoring, and natural resource management. However, data with high spatial resolution typically have low temporal resolution, and those with high temporal resolution often lack spatial detail. For example, Landsat 8 and 9 satellites deliver high spatial resolution images with a 30-meter pixel size but suffer from low temporal resolution, with a 16-day revisit cycle. In contrast, satellites like MODIS and VIIRS provide daily images but with a much coarser spatial resolution (375 meters or more), reducing spatial details. Additionally, there is a lack …

College Of Natural Sciences Newsletter, Spring 2025, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Page 1 Dean's Message from Dr. Sen Subramanian
Page 2 Student Spotlights
Page 3 Kaushik honored, Three-Minute Thesis, & Ice Cores revealed
Page 4 Alumni Spotlight
Page 5 Day of Scholars
Page 6 Cyanide research, Record Research Expenditures, Adhikari awarded Miller Research Award
Page 8 Hanson Receives NSF Grant
Page 9 Snow Lab Research Team
Page 10 Faculty Awards
Page 11 Drone Day
Page 13 Khalaf Awarded Presidential Award

Spatial And Equity Analysis Of The Xeriscape Conversion Rebate Program In Albuquerque, Nm., Claire Jordy

Water Resources Professional Project Reports

With increasing water scarcity concerns threatening water supplies, many cities in the Western U.S. are focusing more effort on their water conservation programs to reduce consumptive water use. The Albuquerque Bernalillo County Water Utility Authority (Water Authority) in Bernalillo County, NM has had several water conservation programs in place since the 1990s, and still, they aim to further reduce water consumption. The Xeriscape Conversion Rebate Program is one of the primary tools to achieve this goal, encouraging customers to convert their high water-use turfgrass lawns to desert-friendly xeriscaping by providing a one-time rebate on their water bill. This rebate program …

Context-Aware Representation: Jointly Learning Item Features And Selection From Triplets, Rodrigo Alves, Antoine Ledent

Research Collection School Of Computing and Information Systems

In areas of machine learning such as cognitive modeling or recommendation, user feedback is usually context-dependent. For instance, a website might provide a user with a set of recommendations and observe which (if any) of the links were clicked by the user. Similarly, there is growing interest in the so-called “odd-one-out” learning setting, where human participants are provided with a basket of items and asked which is the most dissimilar to the others. In both of those cases, the presence of all the items in the basket can influence the final decision. In this article, we consider a classification task …

Decarbonising Digital Infrastructure And Urban Sustainability In The Case Of Data Centres, Felicia H. M. Liu, Karen P. Y. Lai, Bertrand Seah, Winston T. L. Chow

Research Collection College of Integrative Studies

This paper critically assesses the complex interplay between urban transitions of digitisation and sustainability. Building on a mixed-method research design, we unpack the challenges of decarbonising digital infrastructure while attending to urban sustainability goals in a land- and water-scarce country facing significant physical climate risks. We identify transferrable lessons on the economic, technological, and environmental synergies and trade-offs behind data centre development and argue that stewarding the global data centre sector towards sustainability requires an ecosystem-wide approach. We identify implementation gaps across five key dimensions: technological innovation, policy and regulation, finance, infrastructure, and people. We find that the progress and …

The Impact Of Drought And Socio-Economic Factors On Attitudes Toward Immigrants In South Africa, Pamela Antwi-Nimarko

Graduate Program in International Studies Theses & Dissertations

Estimates of the global migrant population have steadily increased, with current data from the International Organization for Migration (IOM) reporting approximately 281 million migrants worldwide. Alongside this growth, anti-immigrant sentiments have risen in many host countries. This study seeks to contribute to the research on attitudes toward immigrants by exploring climate-related factors, particularly drought, as a key influence.

Leveraging a unique dataset combining the World Values Survey (WVS) and Afrobarometer, the study examines how drought, along with individual and contextual factors, affects attitudes toward immigrants. This dataset allows for an in-depth analysis of the direct impact of drought on public …

The Compass - Volume 94 Issue 2 - Complete Issue, Scott R. Beason

The Compass: Earth Science Journal of Sigma Gamma Epsilon

No abstract provided.

Weapons Of Mass Disruption: How Small States Use Cyber To Resist Larger Powers, Russell Alexander Korb

Graduate Program in International Studies Theses & Dissertations

This paper examines the ways in which small states can engage larger actors using cyber- attacks. Since the end of both World Wars, small states have increased in both numbers and relevance, with strong international institutions and norms against military aggression allowing small states to gain legitimacy by the very act of participating in the international system. However, although small states can now do more than simply choose a larger, stronger benefactor to ward off their enemies, they still cannot defy larger powers outright due to the still- dramatic difference in capabilities between them. Those small states interested in confronting …

Humanist Copyright, Jane C. Ginsburg

Faculty Scholarship

This exploration of the role of authorship in copyright law proceeds in three parts: historical, doctrinal, and predictive. First, I will review the development of author-focused property rights in the pre-copyright regimes of printing privileges and in early Anglo-American copyright law through the 1909 U.S. Copyright Act. Second, I will analyze the extent to which the present U.S. copyright law does (and does not) honor human authorship. Finally, I will consider the potential responses of copyright law to the claims of proprietary rights in AI-generated outputs. I will explain why the humanist orientation of U.S. copyright law validates the position …

The Urgency Of Instituting Systemic Cybersecurity Curriculum Within Stem At Secondary Educational Levels In Preparation For Postsecondary Institutions., Robert Spencer

Journal of Cybersecurity Education, Research and Practice

Over the last 20 years, many secondary institutions have made advances developing curriculum defined as “STEM (Science, Engineering and Mathematics)” in order to ensure secondary students are eligible to apply as well excel in technology degree programs at the college and university levels. Although various initiatives exist, there are studies however, which allude to a great possibility that there will be a lack of cybersecurity professionals filling present day and anticipated future positions. Despite a large number of federal and educational enhancements there is need for additional research regarding instituting overall systemic processes and curriculum which supports secondary student transition …

Efficiency Of Labor In Winter Pruning Of Apple Trees Using Technological Innovations, Élio Fillipi Dos Santos, Wendel Paulo Silvestre, Lessandra Silva Rodrigues, Carine Cocco

School of Earth, Environmental, & Marine Sciences Faculty Publications

The increase of new technologies in fruit-growing crops has increased productivity in cultural practices and helped farmers expand their production areas. This work aimed to quantify labor performance in winter pruning of apple trees, using manual and electronic scissors associated with utilizing a pruning platform and ladders. The treatments consisted of two types of pruning shears and two support systems. A pruner carried out pruning for 16 days, with a journey of 10 h per day. The average yield in manual pruning with a ladder was 21.35 plants pruned per hour per man. Using a platform, the yield increased to …

College Of Natural Sciences 2024 Year-End Publication, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Page 2 Dean's Message
Page 3 Department Highlights
Page 4 One Day for State
Page 5 New Students in Wecota
Page 6-8 Faculty Excellence
Page 9 SDSU Physics Students Recognized
Page 9 Prairie Doc Watch Party
Page 10-11 Student Excellence
Page 11 Connections Abroad
Page 12-13 CNS’s Research Centers
Page 14 Connections Abroad
Page 14 Dean Wolf-Hall Retired
Page 15 Outreach Program
Page 15 Events and Traditions
Page 16 Student Spotlight
Page 17 Alumni Spotlight
Page 18-19 SDSU Alum at Paris Paralympics
Page 20 Work Anniversaries & Programs

Springscape: The Nature Coast And The Making Of Modern Florida, 1820s-Present, Douglas E. Ponticos

USF Tampa Graduate Theses and Dissertations

According to an oft-repeated tale, the Florida we know today emerged as a dreamscape of tourism, retirement, and suburbanization during the second half of the twentieth century. Growth victimized nature. This dissertation deeply unsettles that story. The history of the Nature Coast exposes not just nature’s agency but its primacy in the development of modern Florida.

Using surveys, maps, census data, personal correspondence, government documents, business records, timber reports, advertising materials, and hydrological research, this dissertation follows time and water across landscapes, into the Upper Floridan Aquifer, and back out again. Each chapter explores a single landscape within the Nature …

Impact Of Carbonate-Hosted Zn-Pb Ore Deposits On Groundwater Chemistry: Üzümcü-Olgunlar Mining Site (Hakkari, Türkiye), Ci̇han Tuncer, Yüksel Örgün Tutay, Muhterem Demiruğlu

Turkish Journal of Earth Sciences

Hakkari, known for its high economic value Zn-Pb deposits in Türkiye, has been predominantly producing Zn ore for about 20 years. This study investigated the hydrogeochemical properties of groundwater and surface water collected from the vicinity of carbonate-oxide Zn-Pb mine sites in southern Hakkari to evaluate the effects of mineral deposits and mining activities on groundwater chemistry, as there are potential sources of natural pollution. Samples were collected four times at regular intervals during 2021–2022 from points determined upstream, downstream, and around the mine sites, springs, and streams. The samples were analyzed for majorions, trace elements, and isotopes (18O, 2H, …

System Change, Not Climate Change: Collaborative Development Of A Few Nexus Experiential Learning Course For A Justice-Centered Comparative Study Abroad Program, Sonya Ahamed

National Collaborative for Research on Food, Energy, and Water Education (NC-FEW)

The International Honors Program (IHP) on Climate Change: The Politics of Land, Water and Energy Justice has been offered by the School for International Training (SIT) since 2013. This thematic multidisciplinary program currently travels to Morocco, Nepal, and Ecuador for one month each, introducing students to local food, water, and energy challenges in the context of a changing climate. In updating the program following its relaunch in 2023, renewed attention was given to the food, energy, and water nexus from a comparative perspective across and within these countries. This presentation will focus on the development of experiential learning cycles for …

Examining Intersectional Queer Biases In Large Language Models: A Combined Statistical And Visual-Qualitative Approach For Quantification And Explanation, Huu Duong (Chip) Nguyen

Computer Science Senior Theses

Despite significant advancements in research on (intersectional) social biases in Large Language Models (LLMs), intersectional biases affecting subgroups within the LGBTQ+ community remain critically understudied. Existing bias detection methodologies often prioritize quantification but lack depth in explaining the specific stereotypes/biases that shape evaluation metrics. To address these gaps, this study proposes a combined statistical and visual-qualitative approach to quantify and identify persistent intersectional queer biases in five recent, state-of-the-art LLMs through a downstream story generation task. Findings from analysis uncover substantial evidence of stereotypes that perpetuate harmful, reductive narratives against intersectionally marginalized groups within the LGBTQ+ community. To promote public …

Characterizing Rainfall Variability Within A Series Of Storms Over Northern California In February 2017, Parker Jan Malek

Dissertations and Theses

In February 2017, a series of storms with associated atmospheric rivers (ARs) made landfall in the US state of California, dropping large amounts of precipitation over the Sierra Nevada Mountains and their western foothills. The rainfall from these ARs, long, narrow bands of water vapor that transport large amounts of water vapor from the tropics to the mid-latitudes, instigated the near-failure of the Oroville Dam located at the southeastern edge of the Feather watershed outside the city of Oroville in the state's Central Valley. This case study provides a synoptic and mesoscale diagnosis of the drivers of rainfall pulses that …

Next Arrival And Destination Prediction Via Spatiotemporal Embedding With Urban Geography And Human Mobility Data, Pengjiang Li, Zaitian Wang, Xinhao Zhang, Pengfei Wang, Kunpeng Liu

Computer Science Faculty Publications and Presentations

With the development of transportation networks, countless trajectory data are accumulated, and understanding human mobility from traffic data could be helpful for smart cities, urban computing, and urban planning. Extracting valuable insights from traffic data, such as taxi trajectories, can significantly improve residents’ daily lives. There are many studies on spatiotemporal data mining. As we know, arrival prediction or regional function detection encompasses important tasks for traffic management and urban planning. However, trajectory data are often mutilated because of personal privacy and hardware limitations, i.e., we usually can only obtain partial trajectory information. In this paper, we develop an embedding …