Earth Sciences Commons^™

Soil Moisture Regime Effects On Near-Surface Soil Chemical Properties In Alfisols Under Native Tallgrass Prairie In Arkansas, Sydney M. Talley

Crop, Soil and Environmental Sciences Undergraduate Honors Theses

Tallgrass prairie ecosystems provide many crucial ecosystem services, including nutrient cycling and storage, organism habitat, and soil and water conservation. However, tallgrass prairies are considered an endangered ecosystem, particularly in the Ozark Highlands and Grand Prairie regions of Arkansas, where less than 0.05% of Arkansas’ original prairie land area remains. Understanding soil nutrient supplies over time in native tallgrass prairie ecosystems is critical for quantifying the success of restoration and rehabilitation activities. The objective of this study was to evaluate the effects of soil moisture regime (SMR) (i.e., aquic and udic), region (i.e., Ozark Highlands and Grand Prairie), and their …

A Spatial Analysis Of Socioeconomic Characteristics And Community Vulnerability To Natural Hazards In Arkansas, Emma Steuber, Brad Peter

Geosciences Undergraduate Honors Theses

Natural hazards have become more frequent in recent years, and because of their destructive impacts, it is crucial to locate regions that are most affected historically by hazardous events and identify what socioeconomic characteristics co-occur spatially. While many studies have analyzed this relationship at national and state scales, few have focused specifically on Arkansas, and even fewer have incorporated multiple socioeconomic characteristics. Comparing the spatial distribution of community characteristics in Arkansas with zones of common natural hazards is essential for identifying who is most at risk. This study utilizes Geographic Information Science (GISci) to examine and map the spatial relationship …

Examining Extremes: A Comparison Between Machine Learning Based Southwestern Conus Seasonal Drought And High Fire Risk Event Synoptic Climatologies, Ethan M. Greenberg

School of Natural Resources: Dissertations, Theses, and Student Research

The Southwestern United States (SW CONUS), comprised of California, Arizona, Nevada, and Utah, is a vast region that tens of millions of people call home. Hosting ecosystems ranging from grasslands and shrublands to temperate forests and climate zones ranging from Mediterranean climates to arid deserts, the region is nearly unanimously prone to intense droughts and devastating wildfires. While fire weather conditions and drought are often studied separately or mentioned as background conditions for the other, there are relatively few studies that compare the typical meteorological conditions between the two. This study aims to more closely understand the meteorological relationship between …

Gaining Mussel: Evaluating Reintroduction Success Of Native Freshwater Mussels In Nebraska And Eastern Wyoming, Travis A. Moore

School of Natural Resources: Dissertations, Theses, and Student Research

Freshwater mussels are one of the most imperiled groups of organisms in North America, with over two-thirds of species considered threatened, endangered, or of special concern. These long-lived bivalves are essential to stream ecosystems, acting as filter feeders that improve water quality and as indicators of aquatic health. In Nebraska and Wyoming, native mussel populations have declined sharply due to habitat modification, pollution, and reduced connectivity. Two species of particular concern are the Plain Pocketbook Lampsilis cardium, listed as Tier I at-risk in Nebraska, and the Fatmucket Lampsilis siliquoidea, a Tier II at-risk species. In response, state agencies …

On The Paleontology Of Belize, Alson Ovando

Electronic Theses and Dissertations

Paleontology can be considered an underrepresented and emerging area of science in Belize. A primary aim of this thesis is to provide a background of paleontology in Belize and present the first comprehensive study of Quaternary vertebrate fossils known from the country. Quaternary fossil sites across Belize include caves, rivers, and sinkholes. In addition to reviewing and assessing material from known sites, this thesis presents new information and discoveries that were made while investigating Belize’s Quaternary fossil record. This thesis also includes a geospatial model depicting ecoregions in Belize during the last glacial maximum. Overall, the results presented here demonstrate …

Low Methane Emissions From Nutrient-Rich Former River Channels In A Hydrologically Managed Dryland Delta, Siena Stassi, Jude A. Benavides, Chu-Lin Cheng, Marcelo Gomes Da Silva, Nicholas E. Ray, Nathan O. Barros, Rafael M. Almeida

School of Earth, Environmental, & Marine Sciences Faculty Publications

Anthropogenic stresses in dryland regions can alter hydrology, salinization, and biogeochemical processes. How these pressures influence methane (CH4) cycling and emissions from aquatic ecosystems remains poorly understood. Over the course of 1 year, we measured diffusive and ebullitive CH4 emissions from resacas—shallow, hydrologically managed distributary channels prevalent throughout the Lower Rio Grande Valley along the US–Mexico border. Despite warm, nutrient-rich waters, CH4 emissions from resacas were low, and more comparable to rates observed in estuarine systems. CH4 fluxes were positively related to temperature but negatively related to salinity and rainfall. Elevated salinity, driven by evaporation and source water from the …

Landscape Connectivity And Wildlife Access To Water Across An International Border: Barriers And Opportunities For Facilitating Transboundary Movement, Bogdan Chivoiu, Erin L. Koen, Michael J. Osland, Christopher A. Gabler, Jerald T. Garrett, Ernesto Reyes, Stephanie A. Bilodeau, Mitch A. Sternberg, Jude A. Benavides, James Martinez

School of Earth, Environmental, & Marine Sciences Faculty Publications

Rapid global acceleration in the construction of physical barriers along international borders has greatly influenced biodiversity and animal movement. Physical barriers can fragment landscapes, hinder access to essential resources, impact long-distance migrations, and inhibit dispersal and gene flow. The effects of physical barriers on animal movement and landscape connectivity can be exacerbated in dryland environments where access to water is a limiting factor. In recent decades, the construction of border barrier infrastructure has accelerated along the international boundary between the United States and Mexico. Here, we used a landscape connectivity model to investigate the effects of barriers on wildlife access …

Passive Microwave Remote Sensing Of Flash Drought Impacts On Vegetation, Quinton R. Deppert

School of Natural Resources: Dissertations, Theses, and Student Research

In 2002, Dr. Mark Svoboda characterized a new form of drought known as flash drought. Flash drought was defined as a rapid decline in vegetation health caused by severe heat and drought. In recent years, attempts to quantify the impacts of flash drought via precipitation, soil moisture, evapotranspiration, and temperature indicators have proliferated. What has rarely been quantified is what the rapid decline in vegetation health amid flash drought looks like through remote sensing. This is because vegetation health indices like the Normalized Difference Vegetation Index (NDVI) are derived from the visible and infrared regions of the electromagnetic spectrum and …

Exploring Connectivity And Element Distribution In The Critical Zone Using Deep Cores Below Agricultural And Natural Drylands In The American Southwest, Angie Lynette Cano

Open Access Theses & Dissertations

Water movement controls how solutes are transported and stored in arid Critical Zone (CZ) systems. In natural drylands, low precipitation and high evapotranspiration lead to long term salt accumulation in the CZ, whereas irrigation increases water input and increases downward solute transport. This study investigates how agricultural practices alter subsurface hydrology and geochemistry by comparing two deep CZ cores from the southwestern United States: a 50 m deep core beneath a flood irrigated pecan farm named 5R farm, in the Rio Grande Valley in Tornillo, Texas, and a 97.5 m deep core from the Red Lake Playa in the Jornada …

Ecological Insights And Management Implications Of The Global Migratory Connectivity Of Green Turtles, Jaime Restrepo, Dina Nisthar, Harris Wei-Khang Heng, Lily K. Bentley, Corrie Curtice, Sarah Deland, Ei Fujioka, Patrick N. Halpin, Sarah K. Poulin, Roldán A. Valverde

School of Earth, Environmental, & Marine Sciences Faculty Publications

Aim

Green turtles are a widely distributed and highly migratory species; despite extensive data on their movement, there is no species-specific global synthesis on the subject. Based on three decades of published literature and building on previous global analyses, we developed a global network model of migratory connectivity for green turtles to better understand their spatial biology.

Location

Global.

Time Period

1990–2022.

Major Taxa Studied

Green Sea Turtle (Chelonia mydas).

Methods

We conducted a structured literature review extracting georeferenced information on the movement of green turtles from 1990 to 2022, aggregating this information into a single connectivity model, …

Apparent Hack’S Law In River Deltas, Tian Y. Dong, Lawrence Vulis, Hongbo Ma, Alejandro Tejedor, Timothy A. Goudge

School of Earth, Environmental, & Marine Sciences Faculty Publications

River deltas are densely populated, ecologically vital landscapes threatened by rising sea levels. Distributary channel networks disperse sediment to build deltaic land, yet the relationship between the network organization and land building remains elusive. Inspired by Hack’s law, which shows that watershed drainage area scales with channel length in tributary networks, we analyzed a global dataset of distributary networks and found a nearly identical scaling relationship between distributary channel length and nourishment area, the land-building counterpart to drainage area. Despite this apparent global scaling, we further identified two distinct local land-building patterns: uniform delta networks consistently follow Hack’s law, whereas …

Geospatial Assessment Of Agrivoltaic Opportunities And Land Use Requirements In Nigeria, Ifeoluwa Ezekiel Babarinde, Bashir Salisu, Jude A. Benavides, Engil Pereira, Steven M. Grodsky, Rafael M. Almeida

School of Earth, Environmental, & Marine Sciences Faculty Publications

Agrivoltaics, the co-location of agriculture and solar photovoltaic (PV) infrastructure, can deliver co-benefits like reduced plant drought stress and improved yields of shade-tolerant crops, particularly in water-scarce regions. Despite growing global interest, the technical potential and opportunities for agrivoltaics remain poorly understood in many regions facing both food and energy insecurity, such as sub-Saharan Africa. Here we provide a spatial assessment of agrivoltaic opportunities in Nigeria by integrating cropland distribution, solar resources, and water stress. We find that northern states—where cropland is abundant and water-stressed, solar irradiance is high, and electricity access remains low—offer the greatest potential for agrivoltaic systems …

Warming Climate Amplifies Vapor Pressure Deficit Limits On Gross Primary Productivity, Shiqin Xu, Nate G. Mcdowell, Tim R. Mcvicar, Diego G. Miralles, Stephen Sitch, Pablo Sanchez-Martinez, Joshua B. Fisher, Pierre Friedlingstein, Hylke E. Beck, Matthew F. Mccabe

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Ongoing climate warming may profoundly impact terrestrial gross primary productivity (GPP), a key component of the global carbon cycle. However, uncertainty in the relative roles of atmospheric water demand (vapor pressure deficit, VPD) and root-zone soil moisture (SM) limits predictions of drought impacts on GPP. Here, we show that growing-season GPP was more strongly constrained by VPD than SM globally, based on observation-constrained model estimates, satellite retrievals and Dynamic Global Vegetation Model simulations. The importance of VPD increased with higher temperatures and more severe and prolonged droughts. This pattern reflects VPD’s critical role in regulating stomatal conductance and plant hydraulic …

Evaluation Of Sirna-Mediated Knockdown Of Heat Shock Protein 16.2 In Adult Acropora Cervicornis, Edward P. Gniffke, Benjamin D. Young, Keir J. Macartney, Michael S. Studivan, Ian C. Enochs, Erin E. Easton

School of Earth, Environmental, & Marine Sciences Faculty Publications

Acropora cervicornis is a critically endangered Caribbean coral species facing a precipitous decline due to disease and thermal bleaching. To combat the loss of ecologically important reef-building corals, novel molecular approaches can be used to understand mechanisms of resilience and ultimately provide a means to modulate coral performance. In this study, we tested a recently developed method for gene knockdown in adult corals that utilizes short interfering RNAs (siRNAs) and the RNA interference pathway. The Heat Shock Protein 16.2 (HSP16.2) gene in fragments of adult A. cervicornis was targeted for knockdown using a single siRNA construct. RT-qPCR analysis of HSP16.2 …

Mechanisms Behind The Impacts Of Co2 Concentration On Microbial Methanogenesis In Coal Seams, Wang Junyu, Liu Bingjun, Jiang Xiangqing, Chen Ruifeng, Xue Sheng, Zhou Wanlong, Yang Yundu

Coal Geology & Exploration

Background Coal seams exhibit the extensive distribution of a variety of indigenous functional microorganisms. Among these, some archaea enable methane metabolism using CO₂ as a substrate, providing the potential for the biological CO₂ storage and utilization in coal seams. However, conventional studies focus primarily on the degradation characteristics of coal matrix, leading to a lack of a systematic understanding of the mechanisms governing the adjustment of the methanation process in CO₂-bearing environments. Methods This study investigated the bituminous coals with a high volatile content in the Huainan mining area. Using laboratory-scale experiments on methanogenesis through anaerobic …

Dynamic Response Characteristics And Failure Mechanism Of Coal-Rock Combination Under Different Immersion Conditions, Zhang Xiangyang, Tong Zhipeng, Duan Yungang, Yang Weikun, Chen Jianben, Xu Linfeng

Coal Geology & Exploration

Background In practical engineering, the waterproof coal pillar usually suffers from different degrees of dynamic load from the overlying strata, and its internal water distribution is non-uniform. Although the traditional “water content” index can reflect the overall water content, it is difficult to describe the non-uniform characteristics of the soaking space. Therefore, it is of great significance to clarify the dynamic failure mechanism of coal and rock mass under different immersion conditions for stability zoning control. Methods On this basis, the coal–rock combined bodies under three different forms of immersion, namely: complete immersion, unilateral immersion, and non-immersion were prepared. These …

Mechanisms Underlying Lateral Force Applied To A Pdc Cutter On A Pdc Drill Bit During Rotary Rock Breaking, Wei Jiusen, Han Xin, Liu Wei, Gao Deli

Coal Geology & Exploration

Objective To improve the rock-breaking efficiency and durability of drill bits in the theoretical research on the optimal design of drill bits, the key is to systematically reveal both the rock-breaking mechanisms of polycrystalline diamond compact (PDC) cutters and the characteristics of forces applied to them. Methods Existing studies on rock breaking using a single PDC cutter generally adopt a linear or approximately linear cutting mode while neglecting the impacts of the radius of gyration. To address this issue, this study conducted experiments on cylindrical granite samples using a laboratory experimental setting for single-cutter rock breaking. With cutting depth and …

Strategic Layout And Optimization Paths Of The Standard System For The Exploration And Exploitation Of Deep Coalbed Methane, Chen Xinjun, Liu Zengqin, Shen Baojian, Zhao Shihu, Ye Jincheng, Zhang Jiaqi, Wang Tianyun

Coal Geology & Exploration

Objective In China, the deep coalbed methane (CBM) industry has emerged as a key sector for the reserve growth and production addition of natural gas. However, the current CBM technical standard system, which was developed based on shallow CBM practices, is incompatible with the demands for the exploration and development of deep CBM. To address this challenge, this study proposes the optimization paths of the current standard system, aiming to provide standardization support for large-scale exploitation of deep CBM.Methods Deep CBM reservoirs exhibit complex geological conditions of high temperature, pressure, and in-situ stress, as well as the CBM occurrence …

Structural Design And Parameter Optimization Of A Vibration Absorber For Rescue Casing-While-Drilling Rigs, Liu Pu, Yao Ningping, Zou Zujie, Fan Dong, Wei Hongchao, He Binjie

Coal Geology & Exploration

Objective Rescue drilling rigs undergo intense vibration at borehole mouths when operating in a confined underground space of coal mines. To address this issue, this study designed a compact multi-directional, passive dynamic vibration absorber, aiming to improve the operational stability and safety of the rigs. Methods Based on the spring-mass-damping system theory, a stepwise optimization design method was proposed for the longitudinal and transverse dynamic models of the vibration absorber. For the longitudinal vibration model, the particle swarm optimization (PSO) algorithm was applied for multi-objective parameter optimization. In contrast, for the transverse vibration model, the fixed point theory was employed …

Exploring The Vertical Heterogeneity Of Extremely Thick Aquifers In Coal Mines Through Layered Fine-Scale Pumping Tests, Guo Xiaoming

Coal Geology & Exploration

Objective Extremely thick aquifers in mining areas typically exhibit strong heterogeneity and high water yield. Therefore, they are prone to cause severe water inflow in mines and induce water disasters, representing a major factor affecting the mining safety of numerous mines in China. However, the vertical heterogeneity of these aquifers remains poorly understood, emerging as a primary bottleneck in the prevention and control of such water hazards. Methods To scientifically reveal the vertical heterogeneity characteristics of extremely thick aquifers, this study investigated the extremely thick Luohe Formation aquifer in a coal seam roof of a representative coal mine in the …

Mechanisms Behind Thermal Evolution Of The Structural Alignment Of Polycyclic Aromatic Hydrocarbons In Coals: Implications For Structural Transition Of Coal Macromolecules, Song Yu, Jiang Bo, Cheng Guoxi, Zheng Sijian, Li Ming, Ge Yao, Dai Yan, Wang Qian, Feng Guangjun

Coal Geology & Exploration

Objective Coals are highly sensitive to variations in temperature and pressure conditions. The structural evolution of coal macromolecules, driven by tectono-thermal processes, is the key to understanding coal rank transition and geological evolution. The structural alignment of polycyclic aromatic hydrocarbons (PAHs) in coals represents a critical indicator for characterizing coal rank transition and geological evolution. However, due to limited studies, there is a lack of systematic experimental demonstration and theoretical support for the structural alignment and microstructural characteristics of PAHs in coals, as well as their intrinsic relationships with the structural transition of coal macromolecules, during pyrolysis. Methods This study …

Sedimentary Characteristics And Coal Accumulation Patterns Of The Permian Shallow-Water Deltas In Shandong And Its Adjacent Regions, Feng Kai, Li Zengxue, Li Ying, Li Xuchao, Zhang Hui, Zhou Xiaojuan

Coal Geology & Exploration

Objective The Shanxi Formation, deposited during the critical transitional period from the sedimentary filling of epicontinental sea basins to the sedimentation of continental basins, exhibits well-developed shallow-water delta systems and significant coal-forming processes. This study aims to reveal the characteristics of sedimentary environment transformation during the late stage of sedimentary filling of epicontinental sea basins in North China. To this end, the Early Permian shallow-water delta systems in Shandong and its adjacent regions during that period was investigated, including their primary sedimentary characteristics, the predominant bases of sedimentary transformation, and the lithofacies paleogeographic characteristics of coal-forming processes.Methods Based on …

Geological Characteristics And Enrichment-Accumulation Patterns Of Coalbed Methane Within The Jurassic Strata In The Miquan Area Along The Southern Margin Of The Junggar Basin, Wu Luofei, Yang Kangjun, Zhang Jie, Shi Yongxia, Fu Haijiao, Yang Shuguang, Wang Gang, Liu Mengmeng, Li Yueguo, Wang Xiaoming

Coal Geology & Exploration

Objective The southern margin of the Junggar Basin (also referred to as the southern Junggar) possesses abundant medium- to low-rank coalbed methane (CBM) resources, with significant progress achieved in CBM exploration and production. However, there remains a lack of systematic understanding of the genetic mechanisms of CBM within the Middle-Lower Jurassic strata, along with its accumulation and evolution laws, in the Miquan area, southern Junggar. This absence restricts the commercial development of CBM in these strata.Method Focusing on CBM within the Middle-Lower Jurassic Xishanyao and Badaowan formations in the Miquan area, this study further identified the CBM origins and …

Technologies For Controlling Water Inrushes From Coal Seam Floors Under Flowing Water And Their Water Plugging Performance, Yang Zhibin

Coal Geology & Exploration

Objective Limestone water hazards in coal seam floors represent one of the two primary categories of mine water hazards in China. Limestone aquifers are generally characterized by abundant static water reserves and considerable dynamic water recharge. To reduce economic losses and casualties caused by water inrushes from limestone aquifers, post-disaster emergency rescue through grouting for water plugging is frequently carried out under flowing water.Methods Based on numerous cases of water inrush control under flowing water in China and the fundamental requirements for control scheme design, this study presents a systematic review of existing technologies for water inrush control under …

Joint Inversion For Heat Transfer Parameters Of Porous Media With Geothermal-Seepage Coupling Based On A Physics-Informed Neural Network, Zhang Xiao, Yang Duoxing, Cong Lin, Cheng Yimei, Zhang Lianzhong

Coal Geology & Exploration

Background The thermal diffusivity and vertical seepage velocity of porous media are critical to characterizing the mechanisms underlying subsurface heat transfer. These two parameters are typically determined through inversion using temperature data since they are difficult to measure directly. Fiber-optic distributed temperature sensing (FO-DTS) can yield high-resolution, continuous temperature profiles, providing data for parameter identification. However, conventional numerical inversion suffers from limitations such as mesh dependency and sensitivity to initial values when used to process continuous monitoring data. Methods This study proposed a joint geothermal parameter inversion method that integrates FO-DTS data with a physics-informed neural network (PINN). Specifically, the …

Joint Inversion Of Borehole-Surface Direct-Current Resistivity Data, Xu Kaijun, Jin Heran, Cao Danping, Mou Bin, Hu Zuzhi

Coal Geology & Exploration

Objective The conventional inversion of surface direct-current (DC) resistivity data faces challenges such as limited exploration accuracy and depth. This study aims to enhance the accuracy and reliability of exploration in complex engineering and geological settings through the joint inversion of borehole-surface DC resistivity data. Methods First, different geoelectric models were constructed through three-dimensional (3D) forward modeling of full-space DC resistivity. Then, the potential response characteristics under surface and borehole observation methods were systematically analyzed to determine the differences in detection sensitivity between surface and borehole observations. Accordingly, a joint 3D inversion technique for borehole-surface DC resistivity data was developed …

Table Of Contents, The Editors

Coal Geology & Exploration

No abstract provided.

Optical Mechanisms Behind Vitrinite Reflectance Suppression Caused By Strong Anisotropy: A Case Study Of Contact Metamorphic Coals, An Yanfei, He Shuyang, Chen Kaixin, Gao Junhan

Coal Geology & Exploration

Objective For vitrinite with weak anisotropy, which proves uniaxial and optically negative, replacing random vitrinite reflectance (R_ran) with the maximum vitrinite reflectance (R_max) allows for the accurate correction of vitrinite reflectance suppression induced by anisotropy. However, as its anisotropy intensifies, vitrinite exhibits increasingly complex optical properties, rendering it challenging to reflect the thermal metamorphic temperature of vitrinite using R_max. Methods This study investigated the strongly anisotropic vitrinite in coals and natural coke subjected to magma intrusion in the Shitai coal mine, Huaibei City, Anhui Province. Using a reflected-polarized light microscope (R-PLM), an …

Machine Learning-Based Prediction And Experimental Validation Of The Pyrolysis Product Distribution In Tar-Rich Coals, Dong Shuai, Li Hongqiang, Wu Zhiqiang, Yu Zunyi, Lyu Zitao, Guo Wei, Yang Panxi, Fu Keming, Hao Xuanzhi, Liu Gen, Yang Bolun

Coal Geology & Exploration

Background Tar-rich coals serve as an important coal-based oil and gas resource in China, while their pyrolysis product distribution is governed by the coupling effects of coal properties and reaction conditions. Therefore, rapidly identifying the pyrolysis product distribution patterns holds great significance for the resource evaluation and experimental design of tar-rich coals.Methods Existing studies on tar-rich coals suffer from the insufficient integration of exclusive data and limited synergistic prediction capacities for multiple products. To address these issues, this study constructed a dedicated dataset involving proximate analysis, ultimate analysis, elemental molar ratios, maceral composition, and pyrolysis conditions by systematically collecting …

Parameter Optimization And Field Application Of Roof Volume Fracturing Using Horizontal Wells For Coalbed Methane Extraction From Broken-Soft Coal Seams, Zhang Qingli, Sun Siqing, Li Haozhe, Wu Xiaoxuan, Yang Fan, Zheng Yuqi, Li Wenbo

Coal Geology & Exploration

Objective and Method To achieve rapid coalbed methane (CBM) extraction from broken-soft coal seams using surface horizontal wells, this study proposed a volume fracturing technology for coal seam roof using horizontal wells. Focusing coal seam 4-1 in a mining area, this study established a numerical model using finite element analysis (FEA) software Abaqus Using this model, the impacts of in-situ stress on the cross-layer propagation characteristics of multiple fractures were investigated. Through true triaxial hydraulic fracturing experiments, the multi-fracture propagation patterns under varying injection rates of fracturing fluids, perforation cluster numbers, and cluster spacings were analyzed. Using 3D fracturing design …