Preprints
Filtering by Subject: Engineering
Power law scaling model predicts N2O emissions along the Upper Mississippi River basin
Published: 2020-03-03
Subjects: Civil and Environmental Engineering, Engineering, Environmental Engineering
Nitrous oxide, N2O, is widely recognized as one of the most important greenhouse gases, and responsible for stratospheric ozone destruction. A significant fraction of N2O emissions to the atmosphere is from rivers. Reliable catchment-scale estimates of these emissions require both high-resolution field data and suitable models able to capture the main processes controlling nitrogen transformation [...]
Tracking Flooding Phase Transitions and Establishing a Passive Hotline with AI-Enabled Social Media Data
Published: 2020-02-21
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Environmental Monitoring, Environmental Sciences, Hydrology, Physical Sciences and Mathematics, Water Resource Management
Flooding management requires collecting real-time onsite information widely and rapidly. As an emerging data source, social media demonstrates an advantage of providing in-time, rich data in the format of texts and photos and can be used to improve flooding situation awareness. The present study shows that social media data, with additional information processed by Artificial Intelligence (AI) [...]
Realistic River Image Synthesis using Deep Generative Adversarial Networks
Published: 2020-02-20
Subjects: Artificial Intelligence and Robotics, Civil and Environmental Engineering, Computer Sciences, Engineering, Environmental Engineering, Physical Sciences and Mathematics
In this paper, we investigate an application of image generation for river satellite imagery. Specifically, we propose a generative adversarial network (GAN) model capable of generating high-resolution and realistic river images that can be used to support models in surface water estimation, river meandering, wetland loss and other hydrological research studies. First, we summarized an augmented, [...]
Comparison of permeability predictions on cemented sandstones with physics-based and machine learning approaches
Published: 2020-02-06
Subjects: Chemical Engineering, Earth Sciences, Engineering, Hydrology, Multivariate Analysis, Petroleum Engineering, Physical Sciences and Mathematics, Statistics and Probability
Permeability prediction has been an important problem since the time of Darcy. Most approaches to solve this problem have used either idealized physical models or empirical relations. In recent years, machine learning (ML) has led to more accurate and robust, but less interpretable empirical models. Using 211 core samples collected from 12 wells in the Garn Sandstone from the North Sea, this [...]
On the potential of linked-basin tidal power plants: an operational and coastal modelling assessment
Published: 2020-02-02
Subjects: Civil and Environmental Engineering, Computational Engineering, Engineering, Environmental Engineering, Hydraulic Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Single-basin tidal range power plants have the advantage of predictable energy outputs, but feature non-generation periods in every tidal cycle. Linked-basin tidal power systems can reduce this variability and consistently generate power. However, as a concept the latter are under-studied with limited information on their performance relative to single-basin designs. In addressing this, we [...]
Sensitivity Analysis of a Conceptual, Lumped Model Using VARS-TOOL Applied to Western Ghats Catchments of India
Published: 2020-01-30
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Hydrology, Other Civil and Environmental Engineering, Physical Sciences and Mathematics, Water Resource Management
The present work considers the application of Variogram Analysis of Response Surfaces Toolbox (VARS-TOOL) to identify the sensitive parameters of a rainfall-runoff model in the Netravati river basin of Karnataka, India using the global sensitivity analysis method. The statistical bootstrapping method is used to obtain the confidence intervals around each of the sensitivity indices. The VARS-TOOL [...]
High Attenuation Recycled Materials as landfill liners (the HARM project) – A new concept for improved landfill liner design
Published: 2020-01-28
Subjects: Bioresource and Agricultural Engineering, Civil and Environmental Engineering, Earth Sciences, Education, Engineering, Engineering Science and Materials, Environmental Public Health, Environmental Sciences, Geochemistry, Geotechnical Engineering, Hydrology, Medicine and Health Sciences, Physical Sciences and Mathematics, Public Health, Soil Science
A new approach in landfill liner design which combines hydraulic containment of leachate with contaminant attenuation to improve the performance of these environmental control systems at landfills is described. The idea is to re-use readily available industrial waste residues (construction and biomass waste) as additives for natural clay liners, wherein the additives have specific properties [...]
Dynamics of displacement in mixed-wet porous media
Published: 2020-01-23
Subjects: Earth Sciences, Engineering, Fluid Dynamics, Physical Sciences and Mathematics, Physics
We identify a distinct two-phase flow invasion pattern in a mixed-wet porous medium. Time-resolved high-resolution synchrotron X--ray imaging is used to study the invasion of water through a small rock sample filled with oil, characterized by a wide non-uniform distribution of local contact angles both above and below $90^{\circ}$. The water advances in a connected front, but throats are not [...]
A Multivariate Outlier Detection Approach for Water Footprint Assessments in Shale Formations: Case Eagle Ford Play (Texas)
Published: 2020-01-17
Subjects: Civil and Environmental Engineering, Engineering, Environmental Engineering
The increasing trend on water use for hydraulic fracturing (HF) in multiple plays across the U.S. has raised the need to improve the HF water management model. Such approaches require good quality datasets, particularly in water stressed regions. In this work, we presented a QA/QC framework for HF data using a multivariate outlier detection methodology based on five univariate techniques: two [...]
The role of natural clays in the sustainability of landfill liners
Published: 2020-01-10
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Sciences, Geochemistry, Geology, Geotechnical Engineering, Physical Sciences and Mathematics
Engineered synthetic liners on their own are not the ideal solution to protect land, water and living beings against landfill leachate pollution. Despite their impermeability, engineered liners are susceptible to fail during installation and after a few years of landfill operation, and have no attenuation properties. Conversely, natural clay liners can attenuate leachate pollutants by reactions [...]
A web application for hydrogeomorphic flood hazard mapping
Published: 2020-01-09
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Hydraulic Engineering, Hydrology, Physical Sciences and Mathematics
A detailed delineation of flood-prone areas over large regions represents a challenge that cannot be easily solved with today’s resources. The main limitations lie in algorithms and hardware, but also costs, scarcity and sparsity of data and our incomplete knowledge of how inundation events occur in different river floodplains. We showcase the implementation of a data-driven web application for [...]
Single-blind test of airplane-based hyperspectral methane detection via controlled releases
Published: 2020-01-08
Subjects: Education, Engineering, Other Engineering
Methane leakage from point sources in the oil and gas industry is a major contributor to global greenhouse gas emissions. The majority of such emissions come from a small fraction of ``super-emitting" sources. We evaluate the emission detection and quantification capabilities of Kairos Aerospace’s airplane-based hyperspectral imaging methane emission detection system for methane fluxes of 18 to [...]
Goal-Oriented Error Estimation and Mesh Adaptation for Shallow Water Modelling
Published: 2019-12-31
Subjects: Applied Mathematics, Computer Sciences, Engineering, Non-linear Dynamics, Numerical Analysis and Computation, Numerical Analysis and Scientific Computing, Partial Differential Equations, Physical Sciences and Mathematics
Numerical modelling frequently involves a diagnostic quantity of interest (QoI) - often of greater importance than the PDE solution - which we seek to accurately approximate. In the case of coastal ocean modelling the power output of a tidal turbine farm is one such example. Goal-oriented error estimation and mesh adaptation can be used to provide meshes which are well-suited to achieving this [...]
Scheduling of Twin Telescopes and the Impact on Troposphere and UT1 Estimation
Published: 2019-12-13
Subjects: Earth Sciences, Engineering, Other Earth Sciences, Physical Sciences and Mathematics
Recently, several VGOS twin telescopes in Europe were completed. We examine the use of VGOS twin telescopes by a new scheduling approach. This ap- proach is based on integer linear programming and cre- ates uniform distributed observations over time. Sev- eral VLBI intensive sessions are rescheduled involving the VGOS twin telescopes and the impact on the tropo- sphere and UT1 estimation is [...]
Fluid surface coverage showing the controls of rock mineralogy on the wetting state
Published: 2019-12-13
Subjects: Chemical Engineering, Earth Sciences, Engineering, Petroleum Engineering, Physical Sciences and Mathematics
The wetting state is an important control on flow in subsurface multi fluid phase systems, e.g., carbon storage and oil production. Advances in X-ray imaging allow us to characterise the wetting state using imagery of fluid arrangement within the pores of rocks. We derived a model from equilibrium thermodynamics relating fluid coverage of rock surfaces to wettability and fluid saturation. The [...]