Preprints
Filtering by Subject: Engineering
An Online-Learned Neural Network Chemical Solver for Stable Long-Term Global Simulations of Atmospheric Chemistry
Published: 2021-12-02
Subjects: Engineering, Physical Sciences and Mathematics
A major computational barrier in global modeling of atmospheric chemistry is the numerical integration of the coupled kinetic equations describing the chemical mechanism. Machine-learned (ML) solvers can offer order-of-magnitude speedup relative to conventional implicit solvers, but past implementations have suffered from fast error growth and only run for short simulation times (<1 month). A [...]
Optimizing nature-based solutions by combining social equity, hydro-environmental performance, and economic costs through a novel Gini coefficient
Published: 2021-11-15
Subjects: Civil and Environmental Engineering, Civil Engineering, Computational Engineering, Engineering, Environmental Studies, Geographic Information Sciences, Geography, Nature and Society Relations, Operations Research, Systems Engineering and Industrial Engineering, Physical and Environmental Geography, Social and Behavioral Sciences, Systems Engineering
A robust multi-functional framework for widespread planning of nature-based solutions (NBS) must incorporate components of social equity and hydro-environmental performance in a cost-effective manner. NBS systems address stormwater mitigation by increasing on-site infiltration and evaporation through enhanced greenspace while also improving various components of societal well-being, such as [...]
Elastoplastic constitutive behavior and strain localization of a low-porosity sandstone during brittle fracturing
Published: 2021-11-11
Subjects: Engineering, Mechanics of Materials
We investigated the elastoplastic behavior and strain localization of the Zigong sandstone (porosity: 6.5%) during brittle fracturing based on two series of axisymmetric compression experiments. The experiments were conducted under various confining pressures (σ3 = 0 ~ 80 MPa). For each confining pressure, the sandstone specimens were deformed under constant axial and circumferential strain [...]
The future of Alpine Run-of-River hydropower production: climate change, environmental flow requirements, and technical production potential
Published: 2021-11-10
Subjects: Engineering
Past studies on the impacts of climate change (CC) on Alpine hydropower production have focused on high-head accumulation power plants. We provide one of the first comprehensive, simulation-based studies on CC impacts on Alpine Run-of-River (RoR) production, also considering effects of environmental flow requirements and technical increase potential. We simulate future electricity production [...]
Non-linear multiphase flow in hydrophobic porous media
Published: 2021-11-08
Subjects: Engineering, Physical Sciences and Mathematics
Multiphase flow in porous materials is conventionally described by an empirical extension to Darcy’s law which assumes that the pressure gradient is proportional to flow rate. Through a series of two-phase flow experiments, we demonstrate that even when capillary forces are dominant at the pore scale, there is a non-linear intermittent flow regime with a power-law dependence between pressure gradient [...]
Regional analysis of climate projections using Bias Corrected spatial disaggregated super-resolution convolutional neural networks
Published: 2021-11-04
Subjects: Engineering, Life Sciences, Physical Sciences and Mathematics
Climate change is very crucial for ecological systems and society. But Global climate models run at coarse spatial resolution which is difficult to do regional analysis. Regional-scale projections can be obtained by a technique called statistical downscaling which uses past data to find out the high resolution and low-resolution mapping. There are many methods for statistical downscaling of [...]
Flood Risk Assessment and Quantification at the Community and Property Level in the State of Iowa
Published: 2021-10-27
Subjects: Civil and Environmental Engineering, Engineering, Risk Analysis
Flood risk assessment contributes to identifying at-risk communities and supports mitigation decisions to maximize benefits from the investments. Large-scale risk assessments generate invaluable inputs for prioritizing regions for the distribution of limited resources. High-resolution flood maps and accurate parcel information are critical for flood risk analysis to generate reliable outcomes for [...]
Flood Mitigation Data Analytics and Decision Support Framework: Iowa Middle Cedar Watershed Case Study
Published: 2021-10-23
Subjects: Civil and Environmental Engineering, Engineering, Environmental Studies, Geographic Information Sciences, Risk Analysis
Flooding is one of the most frequent natural disasters, causing billions of dollars in damage and threatening vulnerable communities worldwide. Although the impact of flooding can never be diminished, minimizing future losses is possible by taking structural or non-structural mitigation actions. Mitigation applications are often costly practices. However, they can be more feasible for long-term [...]
Linking technical geothermal potential from borehole heat exchangers and heating demand scenarios on a regional scale
Published: 2021-10-20
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Sciences, Natural Resources Management and Policy, Other Earth Sciences, Physical Sciences and Mathematics
Extracting shallow geothermal energy using borehole heat exchangers (BHEs) can help decarbonising the residential heating sector. To assist urban planers and policy makers in developing carbon-neutral heating plans the regional technical shallow geothermal potential must be analysed. Here, we propose a methodology to estimate the technical geothermal potential of BHE fields on a regional scale [...]
Human-in-the-Loop Segmentation of Earth Surface Imagery
Published: 2021-10-16
Subjects: Engineering, Physical Sciences and Mathematics
Segmentation, or the classification of pixels (grid cells) in imagery, is ubiquitously applied in the natural sciences. Manual methods are often prohibitively time-consuming, especially those images consisting of small objects and/or significant spatial heterogeneity of colors or textures. Labeling complicated regions of transition that in Earth surface imagery are represented by collections of [...]
Desiccation of the Transboundary Hamun Lakes between Iran and Afghanistan in Response to Hyro-climatic Droughts and Anthropogenic Activities
Published: 2021-10-13
Subjects: Engineering, Life Sciences
This paper investigates the hydro-climatic reasons behind the desiccation of the Hamun Lakes in the Iran-Afghanistan border. We analyzed changes in the flow of the Hirmand River (90 percent of the total inflow to the lakes) at the international border, and precipitation over this river’s sub-basin during 1960-2016 by calculating standardized indices for precipitation (SPI) and discharge (SDI). We [...]
In-situ hydrogen wettability characterisation for Underground Hydrogen Storage
Published: 2021-10-11
Subjects: Engineering
Hydrogen storage in subsurface aquifers or depleted gas reservoirs represents a viable seasonal and/or long-term energy storage solution. However, currently, there is a scarcity of subsurface petrophysical data for the hydrogen system, limiting modelling work and industrial rollout. In this work, we address the knowledge gap by determining the wettability and Interfacial Tension (IFT) of the [...]
Bedform segregation and locking increase storage of natural and synthetic particles in rivers
Published: 2021-09-24
Subjects: Engineering
While the ecological significance of hyporheic exchange and fine particle transport in rivers is well established, these processes are generally considered irrelevant to riverbed morphodynamics. We show that coupling between hyporheic exchange, suspended sediment deposition, and sand bedform motion strongly modulates morphodynamics and sorts bed sediments. Hyporheic exchange focuses fine-particle [...]
Changes in deep groundwater flow patterns related to oil and gas
Published: 2021-09-17
Subjects: Engineering, Physical Sciences and Mathematics
Large volumes of saline formation water are both produced from and injected into sedimentary basins as a by-product of oil and gas production. Despite this, the location of production and injection wells has not been studied in detail at the regional scale and the effects on deep groundwater flow patterns (i.e. below the base of groundwater protection) possibly driving fluid flow towards shallow [...]
Three-dimensional fluid-driven stable frictional ruptures
Published: 2021-09-13
Subjects: Earth Sciences, Engineering, Environmental Sciences, Geophysics and Seismology, Oil, Gas, and Energy, Physical Sciences and Mathematics, Physics
We investigate the quasi-static growth of a fluid-driven frictional shear crack that propagates in mixed mode (II+III) on a planar fault interface that separates two identical half-spaces of a three-dimensional solid. The fault interface is characterized by a shear strength equal to the product of a constant friction coefficient and the local effective normal stress. Fluid is injected into the [...]