Preprints
Filtering by Subject: Civil and Environmental Engineering
A note on the instability and pattern formation of shrinkage cracks in viscoplastic soils
Published: 2019-11-08
Subjects: Civil and Environmental Engineering, Engineering, Materials Science and Engineering
In this note we present a theoretical study on the conditions for the onset of cracks, as well as the corresponding pattern formation, in saturated viscoplastic soils under isotropic loading (extension). The type of stress applied is left unspecified, to cover a variety of loadings including shrinkage due to dessication, isotropic thermal expansion, mechanical loading and so forth. By treating [...]
Over 1000 rivers accountable for 80% of global riverine plastic emissions into the ocean
Published: 2019-10-24
Subjects: Civil and Environmental Engineering, Engineering, Environmental Engineering
Plastic waste increasingly accumulates in the marine environment, but data on the distribution and quantification of riverine sources, required for development of effective mitigation, are limited. Our new model approach includes geographical distributed data on plastic waste, landuse, wind, precipitation and rivers and calculates the probability for plastic waste to reach a river and [...]
Network topology and rainfall controls on the variability of combined sewer overflows and loads
Published: 2019-10-24
Subjects: Civil and Environmental Engineering, Engineering, Environmental Engineering
Water and pollutant fluxes from combined sewer overflows (CSO) have a significant impact on receiving waters. The random nature of rainfall forcing dominates the variability of sewer discharges, pollutant loads, and concentrations. An analytical model developed here, shows how sewer network topology and rainfall properties variously impact the stochasticity of CSO functioning. Probability [...]
The sensitivity of estimates of multiphase fluid and solid properties of porous rocks to image processing
Published: 2019-10-10
Subjects: Chemical Engineering, Civil and Environmental Engineering, Earth Sciences, Engineering, Hydrology, Petroleum Engineering, Physical Sciences and Mathematics, Transport Phenomena
X-ray microcomputed tomography X-ray microCT) is a rapidly advancing technology that has been successfully employed to study flow phenomena in porous media. It offers an alternative approach to core scale experiments for the estimation of traditional petrophysical properties such as porosity and single-phase flow permeability. It can also be used to investigate properties that control multiphase [...]
Does a damaged fault zone mitigate the near-field landslide risk during supershear earthquakes?—Application to the 2018 magnitude 7.5 Palu earthquake.
Published: 2019-10-03
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geotechnical Engineering, Physical Sciences and Mathematics
The impact of earthquakes can be severely aggravated by cascading secondary hazards. The 2018 Mw 7.5 Palu, Indonesia earthquake led to devastating tsunamis and landslides, while triggered submarine landslides possibly contributed substantially to generate the tsunami. The rupture was supershear over most of its length, but its speed was unexpectedly low, between the S-wave velocity Vs and [...]
Paradoxical impact of sprawling intra-Urban Heat Islets: Reducing mean surface temperatures while enhancing local extremes
Published: 2019-09-09
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Life Sciences, Physical Sciences and Mathematics, Statistics and Probability
Cities are at the forefront of climate change impacts and face a growing burden of adaptation to ensuing natural hazards. Extreme heat is a particularly challenging hazard as persistent heatwaves are locally exacerbated by the Urban Heat Island (UHI) effect. As a result, there is an increasing scientific interest in the influence of diverse urban morphologies on UHI. However, as the temperatures [...]
Hydropower dependency and climate change in sub-Saharan Africa: A nexus framework and evidence-based review
Published: 2019-09-06
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Sciences, Environmental Studies, International and Area Studies, Physical Sciences and Mathematics, Social and Behavioral Sciences
In sub-Saharan Africa, 160 million grid-connected electricity consumers live in countries where hydropower accounts for over 50% of total power supply. A warmer climate with more frequent and intense extremes could result in supply reliability issues. Here, (i) a robust framework to highlight the interdependencies between hydropower, water availability, and climate change is proposed, (ii) the [...]
Building back bigger in hurricane strike zones
Published: 2019-09-03
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Sciences, Geomorphology, Physical Sciences and Mathematics, Sustainability
Despite decades of regulatory efforts in the United States to decrease vulnerability in developed coastal zones, exposure of residential assets to hurricane damage is increasing — even in places where hurricanes have struck before. Comparing plan-view footprints of individual residential buildings before and long after major hurricane strikes, we find a systematic pattern of ‘building back [...]
Emergent self-similarity and scaling properties of fractal intra-Urban Heat Islets for diverse global cities
Published: 2019-09-02
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Sciences, Physical Sciences and Mathematics, Statistics and Probability
Urban areas experience elevated temperatures due to the Urban Heat Island (UHI) effect. However, temperatures within cities vary considerably and their spatial heterogeneity is not well characterized. Here, we use Land Surface Temperature (LST) of 78 global cities to show that the Surface UHI (SUHI) is fractal. We use percentile-based thermal thresholds to identify heat clusters emerging within [...]
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 [...]