Preprints
Filtering by Subject: Engineering
Independent estimates of net carbon uptake in croplands: UAV-LiDAR and machine learning vs. eddy-covariance
Published: 2023-08-30
Subjects: Engineering, Life Sciences, Physical Sciences and Mathematics
Understanding sequestration of organic carbon (C) in agroecosystems is of primary importance for greenhouse gas (GHG) accounting in managed ecosystems, reducing the environmental footprint of land use, and inform crediting programs. However, a broader application of precise C accounting is currently constrained by a limited number of direct flux measurements. Aside well-studied ecosystems via [...]
Quantifying salinity in heterogeneous coastal aquifers through ERT and IP: insights from laboratory and field investigations
Published: 2023-08-24
Subjects: Engineering
The lithological and stratigraphical heterogeneity of coastal aquifers has a great influence on saltwater intrusion (SI). This makes it difficult to predict SI pathways and their persistence in time. In this context, electrical resistivity tomography (ERT) and induced polarization (IP) methods are receiving increasing attention regarding the discrimination between saltwater-bearing and clayey [...]
Thermo-hydro-mechanical simulation of deep excavations in claystone
Published: 2023-08-17
Subjects: Engineering
Marine Cloud Brightening: an airborne concept
Published: 2023-08-12
Subjects: Engineering
Marine cloud brightening (MCB) is a proposed solar radiation modification (SRM) geoengineering technique to enhance marine boundary layer (MBL) cloud albedo. Extant proposals consider 10,000-100,000 autonomous ships spraying seawater, generating and dispersing sea salt nanoparticles. Alternatively, this paper proposes industrially manufacturing NaCl nanoparticles using ethanol anti-solvent brine [...]
Implementation and Evaluation of the Automated Model Reduction (AMORE) Version 1.1 Isoprene Oxidation Mechanism in GEOS-Chem
Published: 2023-08-04
Subjects: Engineering, Physical Sciences and Mathematics
Detailed chemical mechanisms are computationally challenging to include in large-scale chemical transport models such as GEOS-Chem. Employing a graph theory-based automated model reduction (AMORE) algorithm, we developed a new reduced (12 species and 23 reactions) gas-phase isoprene oxidation mechanism. We performed GEOS-Chem simulations for a full year (June 2018 – May 2019) with the default [...]
FIND: A Synthetic weather generator to control drought Frequency, Intensity, and Duration
Published: 2023-08-04
Subjects: Engineering, Other Civil and Environmental Engineering
Water systems worldwide are experiencing climate change-induced shifts in drought properties like frequency, intensity, and duration, affecting water security and reliability. To develop and test effective drought preparedness plans, researchers often use synthetic weather generators to create hydrological scenarios that explore drought variability beyond historical records. Existing weather [...]
A Web-based Decision Support Framework for Optimizing Road Network Accessibility and Emergency Facility Allocation During Flooding
Published: 2023-08-03
Subjects: Civil and Environmental Engineering, Engineering, Environmental Studies, Geographic Information Sciences, Geography, Risk Analysis
Transportation systems can be significantly affected by flooding, leading to physical damage and subsequent adverse impacts such as increased travel distance to essential services. Even though flooding is a frequently recurring phenomenon that can affect thousands of people per event, there are limited accessible online tools available for analyzing and visualizing flood risk for supporting [...]
Estimating Reservoir Sedimentation Using Deep Learning
Published: 2023-08-03
Subjects: Engineering, Physical Sciences and Mathematics
Several reservoirs across the US are filling with sediment, which jeopardizes their functionality and increases maintenance costs. The US Army Corps of Engineers (USACE) developed the Reservoir Sedimentation Information (RSI) system to assess reservoir aggradation and track dam operation suitability for water-resource management and dam safety. The RSI dataset contains historical [...]
Ultrasonic degradation of GenX (HFPO-DA) - Performance comparison to PFOA and PFOS at high frequencies
Published: 2023-07-31
Subjects: Engineering
Sonolytic degradation kinetics of hexafluoropropylene oxide-dimer acid (HFPO-DA or GenX) were studied for the first time at four high ultrasonic frequencies (375, 580, 860 and 1,140 kHz) and three power densities (200, 300 and 400 W/L), and compared to the degradation of previously studied perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). The frequency of 580 kHz displayed [...]
Retrieving the irrigation actually applied at district scale: assimilating high-resolution Sentinel-1-derived soil moisture data into a FAO-56-based model
Published: 2023-07-25
Subjects: Engineering
Irrigation is the most water consuming activity in the world. Knowing the timing and amount of irrigation that is actually applied is therefore fundamental for water managers. However, this information is rarely available at all scales and is subject to large uncertainties due to the great diversity of existing agricultural practices and associated irrigation regimes (full irrigation, deficit [...]
Python workflow for segmenting multiphase flow in porous rocks
Published: 2023-07-25
Subjects: Engineering, Physical Sciences and Mathematics
The need for accurate, consistent and fast image processing has become an important part of the investigation of multiphase flow through porous media. We describe an open-source image processing workflow written in python, using the sci-kit toolbox. We demonstrate the methodology to segment multiple fluids (gas and brine), and the rock grains for a Bentheimer sandstone. This workflow can be [...]
Lower summer lake levels in regulated perialpine lakes, caused by climate change
Published: 2023-07-20
Subjects: Engineering
Alpine regions are particularly sensitive to climate change due to the pronounced effect on snow and glacial melt. In this context, large perialpine lakes play a crucial role in modulating climate change impacts on water resources, which brings together diverse interests. However, climate change studies on river systems rarely include lakes or lake level management. An open question is how to [...]
Commercial-Scale Demonstration of a First-of-a-Kind Enhanced Geothermal System
Published: 2023-07-18
Subjects: Engineering, Physical Sciences and Mathematics
Fervo Energy has completed construction of a commercial enhanced geothermal system (EGS) project and has qualified full functionality of the system through production testing at commercially relevant operating conditions. The project site is located in a nearfield setting adjacent to an operating geothermal power station in north-central Nevada and is designed to deliver an uplift in [...]
Waterflood-CMG production optimization analysis for the Draugen field of Norway
Published: 2023-07-18
Subjects: Engineering
The Draugen field is well-known for producing oil that is then transported to power plant facilities to generate electricity in Draugen. However, with declining oil production (as of 2021) and new necessary electrification contracts, the field may be unable to meet the demand for plant facilities. The current study combines waterflooding and reservoir simulation methods from the Computer [...]
Assisted upscaling of miscible CO¬2-enhanced oil recovery floods using an artificial-neural-network-based optimisation algorithm
Published: 2023-07-13
Subjects: Engineering, Other Engineering
The fine-scale compositional simulations required to accurately model miscible CO2 flooding are unrealistic and highly computationally expensive, and upscaling procedures are required to approximate the behaviour of these fine-scale grids on more realistic coarse-scale models. These procedures include the pseudoisation of relative permeabilities which ensures the matching of large-scale effects [...]