Preprints
Filtering by Subject: Engineering
Hydroclimatic Analysis of Rising Water Levels in the Great Rift Valley Lakes of Kenya
Published: 2021-05-05
Subjects: Engineering, Physical Sciences and Mathematics
Study Region The Great Rift Valley lakes of Kenya have recently experienced significant increases in their water levels, negatively impacting the local communities. This has provoked renewed concerns about the causations, with various geological, anthropogenic and hydro-climatic influences hypothesized as potential causes of the water level rises. Study Focus This study analyses and documents [...]
CO2 capture by pumping surface acidity to the deep ocean
Published: 2021-04-30
Subjects: Chemical Engineering, Climate, Engineering, Environmental Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The majority of IPCC scenarios call for active CO2 removal (CDR) to remain below 2oC of warm- ing. On geological timescales, ocean uptake regulates atmospheric CO2 concentration, with two homeostats driving CO2 uptake: dissolution of deep ocean calcite deposits and terrestrial weathering of silicate rocks, acting on 1ka to 100ka timescales, respectively. Many current ocean-based CDR proposals [...]
FROM THE PAST TO THE FUTURE: SPATIO-TEMPORAL DYNAMICS OF WATER-BALANCE IN A RAPIDLY URBANIZING KATHMANDU VALLEY WATERSHED OF NEPAL
Published: 2021-04-23
Subjects: Civil and Environmental Engineering, Engineering
The resources of the earth are under immense pressure due to the multiple anthropogenic influences. The land resources which largely attribute to the quality as well as quantity of the water, is facing extreme stress due to the rapid urbanization resulting from population growth as well as socio-economic development. It is imperative that the response of hydrological processes to the change in [...]
Decadal Evaluation of the AIRPACT Regional Air Quality Forecast System in the Pacific Northwest from 2009-2018
Published: 2021-04-21
Subjects: Engineering, Physical Sciences and Mathematics
The Air Indicator Report for Public Awareness and Community Tracking (AIRPACT) is a comprehensive, automated air quality forecast system that provides 48-hr in-advance air quality over the Pacific Northwest region (http://lar.wsu.edu/airpact/). Since 2001, the AIRPACT forecasting system has been successfully operated by Washington State University, with the financial support from the Northwest [...]
Microstructural differences between naturally-deposited and laboratory beach sands
Published: 2021-04-14
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Geophysics and Seismology, Geotechnical Engineering, Physical Sciences and Mathematics, Sedimentology
The orientation of and contacts between grains of sand reflect the processes that deposit the sands. Grain orientation and contact geometry also influence mechanical properties. Quantifying and understanding sand microstructure thus provide an opportunity to understand depositional processes better and connect microstructure and macroscopic properties. We compare naturally-deposited beach sands [...]
Microanchored fiber-optic DSS in boreholes allows strain profiling of the shallow subsurface
Published: 2021-03-22
Subjects: Earth Sciences, Engineering
Vertical deformation profiles of subterranean geological formations are conventionally measured by borehole extensometry. Distributed strain sensing (DSS) paired with fiber-optic cables installed in the ground opens up possibilities for acquiring high-resolution static and quasistatic strain profiles of deforming strata, but it is currently limited by reduced data quality due to complicated [...]
A Regional Semi-Distributed Streamflow Model Using Deep Learning
Published: 2021-03-08
Subjects: Civil and Environmental Engineering, Engineering, Environmental Studies, Hydrology
Recent studies have shown that deep learning models in hydrological applications significantly improved streamflow predictions at multiple stations compared to traditional machine learning approaches. However, most studies lack generalization; i.e. researchers are training separate models for each location. The spatial and temporal generalization ability of deep learning models in hydrology that [...]
Strike-slip overprinting of initial co-axial shortening within the toe region of a submarine landslide: a case study from the Angoche Basin, offshore Mozambique.
Published: 2021-03-01
Subjects: Engineering
Submarine landslides (slides) are some of the most voluminous sediment gravity-flows on Earth and they dominate the stratigraphic record of many subaqueous basins. The general kinematics and internal structure of slides are relatively well-understood, although the way in which they increase in volume and internally deformed as they evolve, and how these processes relate to the development of [...]
ROLE OF LITHIUM MINING ON THE WATER STRESS OF THE SALAR DE ATACAMA BASIN
Published: 2021-02-25
Subjects: Engineering
Brines located in the Salar de Atacama are a significant source of lithium worldwide. The extractive method for these minerals is through brine pumping, with subsequent solar evaporation in ponds. In this latter process, part of the water present in brine is evaporated to the atmosphere, leading to the possibility of harvesting lithium and potassium salts. This situation has risen a series of [...]
Stable a posteriori LES of 2D turbulence using convolutional neural networks: Backscattering analysis and generalization to higher Re via transfer learning
Published: 2021-02-24
Subjects: Engineering
There is a growing interest in developing data-driven subgrid-scale (SGS) models for large-eddy simulation (LES) using machine learning (ML). In a priori (offline) tests, some recent studies have found ML-based data-driven SGS models that are trained on high-fidelity data (e.g., from direct numerical simulation, DNS) to outperform baseline physics-based models and accurately capture [...]
Global climate-driven trade-offs between the water retention and cooling benefits of urban greening
Published: 2021-02-23
Subjects: Civil and Environmental Engineering, Construction Engineering and Management, Earth Sciences, Engineering, Environmental Engineering, Environmental Health and Protection, Environmental Sciences, Hydrology, Physical Sciences and Mathematics, Sustainability, Water Resource Management
Heat-related mortality and flooding are pressing challenges for the >4 billion urban population worldwide, exacerbated by increasing urbanization and climate change. Urban greening, such as green roofs and parks, can potentially help address both problems, but the geographical variation of the relative hydrological and thermal performance benefits of such interventions are unknown. Here we [...]
Displacing fishmeal with protein derived from stranded methane
Published: 2021-02-23
Subjects: Bioresource and Agricultural Engineering, Civil and Environmental Engineering, Engineering, Environmental Engineering
Methane emitted and flared from industrial sources across the United States is a major contributor to global climate change. Methanotrophic bacteria can transform this methane into useful protein-rich biomass for animal feed. In the rapidly growing aquaculture industry, this can replace ocean-caught fishmeal, reducing demands on over-harvested fisheries. Here, we analyze the economic potential of [...]
Real-time Flood Mapping on Client-side Web Systems using HAND model
Published: 2021-02-19
Subjects: Civil and Environmental Engineering, Computational Engineering, Engineering
The height above nearest drainage (HAND) model is frequently used to calculate properties of the soil as well as predict flood inundation extents. HAND is extremely useful due to its lack of reliance on prior data, as only the digital elevation model (DEM) is needed. It is close to optimal, running in linear or linearithmic time in the number of cells depending on the values of the heights. It [...]
Numerical modeling of Earth's dynamic surface: a community approach
Published: 2021-02-14
Subjects: Civil and Environmental Engineering, Computer Sciences, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Geology, Geomorphology, Glaciology, Hydrology, Numerical Analysis and Scientific Computing, Other Environmental Sciences, Physical Sciences and Mathematics, Sedimentology, Soil Science, Stratigraphy
Computational modelling occupies a unique niche in Earth environmental sciences. Models serve not just as scientific technology and infrastructure, but also as digital containers of the scientific community's understanding of the natural world. As this understanding improves, so too must the associated software. This dual nature---models as both infrastructure and hypotheses---means that [...]
Using Landsat and Sentinel Imagery to Monitor Alfalfa and Grass Pastures in Western Colorado
Published: 2021-02-10
Subjects: Engineering, Physical Sciences and Mathematics
Crop phenology of alfalfa and grass pasture fields on the western slope of Colorado, USA, was tracked using an NDVI time series derived from Landsat 7 (ETM+), Landsat 8 (OLI) and Sentinel 2a MSI to obtain high temporal frequency information of crop growth stages. These perennial pastures, which occupy a majority of irrigated land in the region and typically have more than one growing/cutting [...]