Preprints
Filtering by Subject: Engineering
On the thermo-poro-mechanics of chemically active faults
Published: 2020-05-21
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geophysics and Seismology, Geotechnical Engineering, Physical Sciences and Mathematics
Shear zones in outcrops and core drillings on active faults commonly reveal two scales of localization, with centimeter to tens of meters thick deformation zones embedding much narrower zones of mm- to cm-scale. The narrow zones are often attributed to some form of fast instability such as earthquakes or slow slip events. Surprisingly, the double localisation phenomenon seem to be independent of [...]
Using Bayesian Hierarchical Modelling to capture cyanobacteria dynamics in Northern European lakes
Published: 2020-05-21
Subjects: Civil and Environmental Engineering, Engineering, Environmental Engineering
Cyanobacteria blooms in lakes and reservoirs currently threaten water security and affect the ecosystem services provided by these freshwater ecosystems, such as drinking water and recreational use. Climate change is expected to further exacerbate the situation in the future because of higher temperatures, extended droughts and nutrient enrichment, due to urbanisation and intensified agriculture. [...]
Probabilistic soil moisture dynamics of water- and energy-limited ecosystems
Published: 2020-05-17
Subjects: Agriculture, Agronomy and Crop Sciences Life Sciences, Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Forest Sciences, Hydrology, Life Sciences, Physical Sciences and Mathematics, Plant Sciences, Statistical Models, Statistics and Probability
This paper presents an extension of the stochastic ecohydrological model for soil moisture dynamics at a point of Rodriguez-Iturbe et al. (1999) and Laio et al. (2001). In the original model, evapotranspiration is a function of soil moisture and vegetation parameters, so that the model is suitable for water-limited environments. Our extension introduces a dependence on maximum evapotranspiration [...]
Detecting Ground Deformation in the Built Environment using Sparse Satellite InSAR data with a Convolutional Neural Network
Published: 2020-05-14
Subjects: Earth Sciences, Electrical and Computer Engineering, Engineering, Other Earth Sciences, Physical Sciences and Mathematics, Signal Processing
The large volumes of Sentinel-1 data produced over Europe are being used to develop pan-national ground motion services. However, simple analysis techniques like thresholding cannot detect and classify complex deformation signals reliably making providing usable information to a broad range of non-expert stakeholders a challenge. Here we explore the applicability of deep learning approaches by [...]
A Near-Real-Time Approach for Monitoring Forest Disturbance Using Landsat Time Series: Stochastic Continuous Change Detection
Published: 2020-05-13
Subjects: Earth Sciences, Engineering, Other Earth Sciences, Physical Sciences and Mathematics
Forest disturbances greatly affect the ecological functioning of natural forests. Timely information regarding extent, timing and magnitude of forest disturbance events is crucial for effective disturbance management strategies. Yet, we still lack an acute, near-real-time and high-performance remote sensing tools for monitoring abrupt and subtle forest disturbances. This study presents a new [...]
Predicting the yield stress of a 3D printed porous material from its internal structure
Published: 2020-05-12
Subjects: Engineering, Materials Science and Engineering, Structural Materials
The design of any engineering structure requires the knowledge, and therefore determination, of the yield, i.e. limit of elasticity, for the building material. Whilst destructive experimental testing is currently necessary to do so, our work is part of initiatives which aim at deriving the yield without such laboratory experiments. The seminal work of Gurson (1977) on a simplified pore structure, [...]
Permeability hysteresis from micro-channels opening during dissolution/reprecipitation cycle
Published: 2020-05-11
Subjects: Civil and Environmental Engineering, Computational Engineering, Engineering, Hydraulic Engineering
Permeability is a critical parameter for geological resources characterisation. Its evolution with respect to porosity is particularly interesting and many research initiatives focus on deriving such relationships, to understand some hydraulic impacts of microstructure alteration. Permeability evolution from chemical reactions for instance can become complex as flow channels may open during rock [...]
Three Common Statistical Missteps We Make in Reservoir Characterization
Published: 2020-05-11
Subjects: Chemical Engineering, Earth Sciences, Engineering, Geology, Petroleum Engineering, Physical Sciences and Mathematics, Statistical Methodology, Statistics and Probability
Reservoir characterization analysis resulting from incorrect applications of statistics can be found in the literature, particularly in applications where integration of various disciplines is needed. Here, we look at three misapplications of ordinary least squares linear regression (LSLR) and show how they can lead to poor results and offer better alternatives, where available. The issues are [...]
On doing large-scale hydrology with Lions: Realising the value of perceptual models and knowledge accumulation
Published: 2020-05-08
Subjects: Earth Sciences, Engineering, Environmental Sciences, Hydrology, Physical Sciences and Mathematics
Moving the study domain in hydrology to larger and larger regions leaves us with significant knowledge gaps because we are unable to observe the hydrology of many parts of the world, while in-depth hydrologic studies cover only a fraction of our landscape. On medieval maps, knowledge gaps were shown as images of lions. How do we best acknowledge and reduce these gaps in hydrology, i.e. our [...]
Estimating Submicron Aerosol Mixing State at the Global Scale with Machine Learning and Earth System Modeling
Published: 2020-05-07
Subjects: Atmospheric Sciences, Civil and Environmental Engineering, Computational Engineering, Computer Sciences, Earth Sciences, Engineering, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
This study integrates machine learning and particle-resolved aerosol simulations to develop emulators that predict sub-micron aerosol mixing state indices from the Earth System Model (ESM) simulations. The emulators predict aerosol mixing state using only ESM bulk aerosol species concentrations, which do not by themselves carry mixing state information. Here we used PartMC as the [...]
Evaluating Controller Performance and Placement on System-level Urban Flooding Reduction and Water Quality Improvement
Published: 2020-05-07
Subjects: Civil and Environmental Engineering, Civil Engineering, Engineering, Environmental Engineering
Increases in urbanization and climate change are forcing urban drainage engineers to more effectively leverage stormwater storage facilities to minimize flooding and water quality impacts. This process becomes increasingly challenging due to the operations of storage coordination across the system-level watershed. This study presents a system-level real-time control simulation for assessing [...]
Permeability computation of high resolution µCTscan with an unfitted boundary method to improve accuracy
Published: 2020-05-07
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geophysics and Seismology, Hydraulic Engineering, Hydrology, Physical Sciences and Mathematics
Flow simulations on porous media, reconstructed from Micro-Computerised Tomography (μCT)-scans, is becoming a common tool to compute the permeability of rocks. In order for the value of this homogenised hydraulic property to be representative of the rock at a continuum scale, the sample considered needs to be at least as large as the Representative Elementary Volume. More- over, the numerical [...]
A Data-driven Improved Fuzzy Logic Control Optimization-simulation Tool for Reducing Flooding Volume at Downstream Urban Drainage Systems
Published: 2020-04-30
Subjects: Civil and Environmental Engineering, Civil Engineering, Engineering, Environmental Engineering
The uncertainty of climate change and urbanization imposed additional stress for urban drainage systems (UDSs) by intensifying rainfall frequency and magnifying peak runoff rate. UDSs are among the stormwater infrastructures that can be controlled in real-time for mitigating downstream urban flooding. In this paper, a data-driven improved real-time control optimization-simulation tool called [...]
A Performance Comparison of Unsupervised Machine Learning Algorithms for Clustering Water Depth Datasets at Urban Drainage Systems
Published: 2020-04-30
Subjects: Civil and Environmental Engineering, Civil Engineering, Engineering, Environmental Engineering
As sensor measurements emerge in urban water systems, data-driven unsupervised machine learning algorithms have been drawn tremendous interest in infrastructure monitoring, flow prediction, and pollutant warning recently. However, most of them are applied in water distribution systems, and few studies consider using unsupervised clustering analysis to group the time-series hydraulic-hydrologic [...]
Protecting rivers by integrating supply-wastewater infrastructure planning and coordinating operational decisions
Published: 2020-04-30
Subjects: Civil and Environmental Engineering, Engineering, Environmental Engineering
Placing water quality in rivers at the centre of water infrastructure planning and management is an important objective. In response there has been a range of whole system analyses. Few studies, however, consider both abstraction (water removed from rivers) and discharge (water returned) to inform the future planning of water systems. In this work we present a systems approach to analysing future [...]