Preprints
Filtering by Subject: Engineering
Using nano-XRM and high-contrast imaging to inform micro-porosity permeability during Stokes-Brinkman single and two-phase flow simulations on micro-CT images
Published: 2019-05-18
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Hydrology, Physical Sciences and Mathematics
Carbonate rocks have particularly complex and multiscale pore systems which are weakly understood. In this study we use combined experimental, modelling, and pore space generation methods to tackle the impact of micro-porosity on the bulk flow properties of Estaillades limestone. First, a nano-core from a microporous grain of Estaillades Limestone was scanned using x-ray nano tomography [...]
Well-being loss: a comprehensive metric for household disaster resilience
Published: 2019-05-17
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Studies, Physical Sciences and Mathematics, Risk Analysis, Social and Behavioral Sciences
Natural disaster risk assessments typically consider environmental hazard and physical damage, neglecting to quantify how asset losses affect households’ well-being. However, for a given asset loss, a wealthy household might easily recover, while a poor household might suffer from major, long-lasting impacts. Ignoring such differential impacts can lead to inequitable interventions and exacerbate [...]
A Novel Hybrid Finite Element-Spectral Boundary Integral Scheme for Modeling Earthquake Cycles: Application to Rate and State Faults with Low-Velocity Zones
Published: 2019-05-14
Subjects: Applied Mechanics, Earth Sciences, Engineering, Geophysics and Seismology, Mechanical Engineering, Physical Sciences and Mathematics
We present a novel hybrid finite element (FE) - spectral boundary integral (SBI) scheme that enables efficient simulation of earthquake cycles. This combined FE-SBI approach captures the benefits of finite elements in modelling problems with nonlinearities, as well as the computational superiority of SBI. The domain truncation enabled by this scheme allows us to utilize high-resolution finite [...]
Using a Superconducting Gravimeter in Support of Absolute Gravity Campaigning — A feasibility study
Published: 2019-05-13
Subjects: Earth Sciences, Engineering, Life Sciences, Other Earth Sciences, Physical Sciences and Mathematics
Preparing for joint analysis of absolute gravity (AG) campaigns, this report investigates whether a stationary superconducting gravimeter (SCG) can provide a long-term stable measurement of site-dependent perturbations that help in reduction to the local value of little-$g$ and its secular rate of change. The crucial element concerns the discrimination of instrumental drift components from trends [...]
On the automatic and a priori design of unstructured mesh resolution for coastal ocean circulation models
Published: 2019-05-10
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Civil and Environmental Engineering, Other Earth Sciences, Physical Sciences and Mathematics
This study investigates the design of unstructured mesh resolution and its impact on the modeling of barotropic tides along the United States East Coast and Gulf Coast (ECGC). A discrete representation of a computational ocean domain (mesh design) is necessary due to finite computational resources and an incomplete knowledge of the physical system (e.g., shoreline and seabed topography). The [...]
A spatially resolved fluid-solid interaction model for dense granular packs/Soft-Sand.
Published: 2019-05-09
Subjects: Earth Sciences, Engineering, Materials Science and Engineering, Physical Sciences and Mathematics
Fluid flow through dense granular packs or soft sands can be described as a Darcy s flow for low injection rates, as the friction between grain-grain and grain-walls dominate the solid system behaviour. For high injection rates, fluid forces can generate grain displacement forming flow channels or ``fractures, which in turn modify local properties within the system, such as permeability and [...]
Analysis of Persistence in the Flood Timing and the Role of Catchment Wetness on Flood Generation in a Large River Basin in India
Published: 2019-05-08
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Hydraulic Engineering, Hydrology, Physical Sciences and Mathematics, Statistics and Probability
This study contributes to the understanding of the timing of occurrence of floods and role of the catchment wetness in flood processes (i.e., magnitude and the timing of floods) over one of the largest tropical pluvial river basin system, Mahanadi, in India. Being located in the monsoon ‘core’ region (18° - 28° N latitude and 73° - 82° E longitude) and its proximity to Bay of Bengal, Mahanadi [...]
Trends of hydroclimatic intensity in Colombia
Published: 2019-05-08
Subjects: Applied Statistics, Civil and Environmental Engineering, Climate, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Hydrology, Life Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Risk Analysis, Statistics and Probability, Water Resource Management
Prediction of changes in precipitation in upcoming years and decades caused by global climate change associated with the greenhouse effect, deforestation and other anthropic perturbations is a practical and scientific problem of high complexity and huge consequences. To advance toward this challenge we look at the daily historical record of all available rain gauges in Colombia to estimate an [...]
Probabilistic space- and time-interaction modeling of main-shock earthquake rupture occurrence
Published: 2019-04-29
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geophysics and Seismology, Physical Sciences and Mathematics, Statistical Models, Statistics and Probability, Structural Engineering
This paper presents a probabilistic formulation for modeling earthquake rupture processes of mainshocks. A correlated multivariate Bernoulli distribution is used to model rupture occurrence. The model captures time interaction through the use of Brownian passage-time (BPT) distributions to assess rupture interarrival in multiple sections of the fault, and it also considers spatial interaction [...]
Bayesian parameter estimation for space and time interacting earthquake rupture model using historical and physics-based simulated earthquake catalogs
Published: 2019-04-25
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Geophysics and Seismology, Physical Sciences and Mathematics, Risk Analysis
This paper presents a robust parameter estimation technique for a probabilistic earthquake hazard model that captures time and space interactions between earthquake mainshocks. The approach addresses the existing limitations of parameter estimation techniques by developing a Bayesian formulation and leveraging physics-based simulated synthetic catalogs to expand the limited datasets of historical [...]
Influence of dissolution on frictional properties of carbonate faults
Published: 2019-04-25
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Geophysics and Seismology, Physical Sciences and Mathematics
Velocity stepping experiments have been performed on a simulated calcite gouge using an annular shear apparatus to investigate the effect of dissolution on the frictional properties of a carbonate fault. The tested material was put in contact with hydrochloric acid at different concentration in order to dissolve the grains. Particle size analysis shows that the small grains tend to disappear due [...]
A heuristic model inversion for coupled thermo-hydro-mechanical modeling of triaxial experiments
Published: 2019-04-25
Subjects: Applied Mathematics, Civil and Environmental Engineering, Engineering, Geotechnical Engineering, Physical Sciences and Mathematics
As multiphysics geomechanical models get developed, their increasing complexity and number of parameters make it particularly difficult to calibrate against experimental data. In this contribution, we present a heuristic workflow to invert for parameters of a coupled Thermo-Hydro-Mechanical (THM) model in a way that helps the theoretical modellers refine their definition of the underlying [...]
Impacts of Coal Resource Development on Surface Water Quality in a Multi-jurisdictional Watershed in the Western United States
Published: 2019-04-19
Subjects: Civil and Environmental Engineering, Engineering, Environmental Engineering
This study focuses on water quality and quantity impacts from natural resource development on watersheds originating on Crow tribal lands in southeastern Montana. My field research analysis will focus on the surface water quality in three adjacent watersheds. This study will determine impacts to water quality from reclaimed coal mine spoils surface runoff and produced water discharge from coal [...]
Are Detected Trends in Flood Magnitude and Shifts in the Timing of Floods of A Major River Basin in India, Linked To Anthropogenic Stressors?
Published: 2019-04-10
Subjects: Applied Statistics, Civil and Environmental Engineering, Earth Sciences, Engineering, Hydraulic Engineering, Hydrology, Mathematics, Physical Sciences and Mathematics, Statistics and Probability
Analyzing of trends in flood magnitude and the timing of the dates of flood occurrences of large river basins across the globe are essential for understanding changes in water availability (high or low flows) and assessing the fidelity of global hydrological models. Our research is motivated by the recent six major consecutive floods in Mahanadi (years: 2001, 2003, 2006, 2008, 2011 and 2013) [...]
What has Global Sensitivity Analysis ever done for us? A systematic review to support scientific advancement and to inform policy-making in earth system modelling
Published: 2019-04-08
Subjects: Civil and Environmental Engineering, Computer Sciences, Earth Sciences, Engineering, Environmental Sciences, Life Sciences, Mathematics, Medicine and Health Sciences, Physical Sciences and Mathematics, Risk Analysis, Statistics and Probability
Computer models are essential tools in the earth system sciences. They underpin our search for understanding of earth system functioning and support decision- and policy-making across spatial and temporal scales. To understand the implications of uncertainty and environmental variability on the identification of such earth system models and their predictions, we can rely on increasingly powerful [...]