Preprints
Filtering by Subject: Civil and Environmental Engineering
Speeding up PPP ambiguity resolution using triple-frequency GPS/BeiDou/Galileo/QZSS data
Published: 2019-08-29
Subjects: Aerospace Engineering, Civil and Environmental Engineering, Engineering, Navigation, Guidance, Control and Dynamics
Precise point positioning (PPP) has been suffering from slow convergences to ambiguity-fixed solutions. It is expected that this situation can be relieved or even resolved using triple-frequency GNSS data. We therefore attempt an approach where uncombined triple-frequency GPS/BeiDou/Galileo/QZSS (Quasi-zenith satellite system) data are injected into PPP, whereas their raw ambiguities are mapped [...]
Imbibition in porous media: correlations of displacement events with pore-throat geometry and the identification of a new type of pore snap-off
Published: 2019-08-23
Subjects: Chemical Engineering, Civil and Environmental Engineering, Complex Fluids, Dynamics and Dynamical Systems, Engineering, Engineering Science and Materials, Environmental Engineering, Materials Science and Engineering, Mechanics of Materials, Petroleum Engineering, Transport Phenomena
The displacement of a non-wetting fluid by a wetting fluid in porous media, called imbibition, is important in many natural and industrial processes. During imbibition, the wetting fluid invades the pore space through a series of competitions between piston-like displacement, film and corner flow, snap-off, pore bypassing and trapping. Our understanding of these fundamental pore-scale [...]
Realistic and simplified models of plant and leaf area indices for a seasonally dry tropical forest
Published: 2019-08-06
Subjects: Civil and Environmental Engineering, Desert Ecology, Ecology and Evolutionary Biology, Engineering, Environmental Engineering, Forest Management, Forest Sciences, Life Sciences, Plant Sciences, Research Methods in Life Sciences
Leaf Area Index (LAI) models that consider all phenological stages have not been developed for the Caatinga, the largest seasonally dry tropical forest in South America. LAI models that are currently used show moderate to high covariance when compared to in situ data, but they often lack accuracy in the whole spectra of possible values and do not consider the impact that the stems and branches [...]
SediNet: A configurable deep learning model for mixed qualitative and quantitative optical granulometry
Published: 2019-07-31
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Geomorphology, Physical Sciences and Mathematics
I describe a configurable machine-learning framework to estimate a suite of continuous and categorical sedimentological properties from photographic imagery of sediment, and to exemplify how machine learning can be a powerful and flexible tool for automated quantitative and qualitative measurements from remotely sensed imagery. The model is tested on a large dataset consisting of 400 images and [...]
Can barrier islands survive sea-level rise? Quantifying the relative role of tidal deltas and overwash deposition
Published: 2019-07-18
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Environmental Engineering, Geology, Geomorphology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology
Accepted open-access publication available at: https://doi.org/10.1029/2019GL085524 Barrier island response to sea-level rise depends on their ability to transgress and move sediment onto and behind the barrier, either through flood-tidal delta deposition, or via overwash. Our understanding of these processes over decadal or longer timescales, however, is limited. Here we [...]
Information-theoretic Portfolio Decision Model for Optimal Flood Management
Published: 2019-06-27
Subjects: Civil and Environmental Engineering, Civil Engineering, Computational Engineering, Earth Sciences, Engineering, Environmental Engineering, Environmental Health and Protection, Environmental Sciences, Geomorphology, Hydraulic Engineering, Hydrology, Life Sciences, Natural Resources and Conservation, Natural Resources Management and Policy, Operations Research, Systems Engineering and Industrial Engineering, Other Civil and Environmental Engineering, Other Engineering, Other Environmental Sciences, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics, Probability, Risk Analysis, Statistics and Probability, Sustainability, Systems Engineering, Water Resource Management
The increasing impact of flooding urges more effective flood management strategies to guarantee sustainable ecosystem development. Recent catastrophes underline the importance of avoiding local flood management, but characterizing large scale basin wide approaches for systemic flood risk management. Here we introduce an information-theoretic Portfolio Decision Model (iPDM) for the optimization of [...]
Decentralized Flood Forecasting Using Deep Neural Networks
Published: 2019-06-22
Subjects: Civil and Environmental Engineering, Engineering, Environmental Engineering, Life Sciences, Other Life Sciences
Predicting flood for any location at times of extreme storms is a longstanding problem that has utmost importance in emergency management. Conventional methods that aim to predict water levels in streams use advanced hydrological models still lack of giving accurate forecasts everywhere. This study aims to explore artificial deep neural networks performance on flood prediction. While providing [...]
Global resource potential of seasonal pumped-storage
Published: 2019-06-20
Subjects: Civil and Environmental Engineering, Engineering, Geotechnical Engineering, Hydraulic Engineering
The risk of seasonal mismatches between electricity supply and demand is increasing due to expanded use of wind, solar and hydropower resources. Power system planners are thus in search of low-cost seasonal energy storage options. Seasonal Pumped-Storage (SPS) can provide short, medium and long-term energy storage at a relatively low-cost and provides co-benefits in the form of freshwater storage [...]
Optimizing Regional Climate Model Output for Hydro-Climate Applications in the Eastern Nile Basin
Published: 2019-06-18
Subjects: Civil and Environmental Engineering, Climate, Earth Sciences, Engineering, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
This study focuses on the Eastern Nile (EN) Basin, most of whose water flows into the High Aswan Dam (HAD), Egypt. It is, therefore, crucial to have an accurate hydrological assessment overtime to plan water resource management in the area. With complex topography, it is important to capture most of the physics captured with the least bias in meteorological information. Weather Research and [...]
Technical note: Limitations on the use of space borne differential SAR interferometry for systematic monitoring and failure forecast of alpine landslides
Published: 2019-06-16
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Geology, Geotechnical Engineering, Physical Sciences and Mathematics
Recent advances on satellite geodesy have boosted our capabilities to map and monitor landslides globally with unprecedented resolutions. In this scenario, differential interferometry of space borne synthetic aperture radar imagery (DInSAR) plays a major role in identifying surface displacements associated to slope instabilities and in monitoring their spatial and temporal evolution. However, [...]
A Temperature- and Pressure-Sensitive Visco-Plasticity Theory based on Interface Mechanisms for Sedimentary Rocks
Published: 2019-05-24
Subjects: Civil and Environmental Engineering, Engineering, Geotechnical Engineering, Materials Science and Engineering, Other Materials Science and Engineering
Constitutive modelling in geotechnical engineering and applied earth sciences is facing the challenge of assessing the long-term potential of both man-made and natural geohazards. This involves designing engineering operations for length scales and timescales well beyond those observable in the laboratory. In order to bridge the gap between scales, study rock behaviours well beyond their yield [...]
On the stability of deep-seated landslides. The cases of Vaiont (Italy) and Shuping (Three Gorges Dam, China)
Published: 2019-05-24
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geology, Geotechnical Engineering, Physical Sciences and Mathematics
Deep-seated catastrophic landslides are among the most powerful natural hazards on earth. These devastating events are not possible to be prevented yet, because of their large volumes and sudden acceleration phase. The present study suggests a new method to detect when a landslide will turn unstable, giving both a time-window to evacuate the area that is going to be affected and critical values [...]
An assessment of the wind influence in local inertial 1D hydrodynamic flow routing
Published: 2019-05-23
Subjects: Civil and Environmental Engineering, Engineering, Environmental Engineering
One-dimensional (1D) hydrodynamic modeling studies generally do not take into account the influence of wind, although literature experiences demonstrate the importance of this information in some cases. In this context, the present work had the objective to investigate this matter further, studying the influence of wind on hydrodynamic 1D modeling results and proposing an abacus for the rapid [...]
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: 2019-05-17
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 [...]