Preprints
Filtering by Subject: Civil and Environmental Engineering
Quantifying natural delta variability using a multiple-point geostatistics prior uncertainty model
Published: 2018-09-30
Subjects: Artificial Intelligence and Robotics, Civil and Environmental Engineering, Computer Sciences, Earth Sciences, Electrical and Computer Engineering, Engineering, Environmental Engineering, Geology, Geomorphology, Other Civil and Environmental Engineering, Other Engineering, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Theory and Algorithms
We address the question of quantifying uncertainty associated with autogenic pattern variability in a channelized transport system by means of a modern geostatistical method. This question has considerable relevance for practical subsurface applications as well, particularly those related to uncertainty quantification relying on Bayesian approaches. Specifically, we show how the autogenic [...]
Learning about climate change uncertainty enables flexible water infrastructure planning
Published: 2018-09-29
Subjects: Civil and Environmental Engineering, Civil Engineering, Climate, Computer Sciences, Earth Sciences, Engineering, Environmental Sciences, Hydrology, Numerical Analysis and Scientific Computing, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Statistics and Probability, Water Resource Management
Water resources planning requires making decisions about infrastructure development under substantial uncertainty in future regional climate conditions. However, uncertainty in climate change projections will evolve over the 100-year lifetime of a dam as new climate observations become available. Flexible strategies in which infrastructure is proactively designed to be changed in the future have [...]
Estimating flood quantiles at ungauged sites using nonparametric regression methods with spatial components
Published: 2018-09-26
Subjects: Civil and Environmental Engineering, Engineering, Other Civil and Environmental Engineering
Prediction of flood quantiles at ungauged sites has been investigated using several nonparametric regression methods including: local regression based on regions of influence, neural networks and generalized additive models (GAM). These methods were used to describe the relationship between run-off variables and catchment descriptors to predict flood quantiles. Previous work reported the presence [...]
A nationwide regional flood frequency analysis at ungauged sites using ROI/GLS with copulas and super regions
Published: 2018-09-26
Subjects: Civil and Environmental Engineering, Engineering, Other Civil and Environmental Engineering
Region of influence is a common approach to estimate runoff information at ungauged locations. To estimate flood quantiles from annual maximum discharges, the Generalized Least Squares (GLS) framework has been recommended to account for unequal sampling variance and intersite correlation, which requires a proper evaluation of the sampling covariance structure. Since some jurisdictions do not [...]
Backwater Controls on the Sedimentology, Kinematics and Geometry of Bar Deposits in Coastal Rivers
Published: 2018-09-23
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Geology, Geomorphology, Hydrology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
The backwater reach of coastal rivers is associated with considerable spatial and temporal variability in water and sediment flux. Here we test the hypothesis that the spatial and temporal variability in water flux and particle sizes in transport result in systematic changes in the geometry of bank-attached bars across the backwater transition. Measured transverse slopes of bank-attached bars in [...]
Creating a Model to Optimize and Evaluate the Heat-Reducing Capacity of Green Infrastructure
Published: 2018-09-10
Subjects: Civil and Environmental Engineering, Engineering, Environmental Engineering, Environmental Public Health, Environmental Studies, Medicine and Health Sciences, Public Health, Social and Behavioral Sciences
As global warming increases temperatures worldwide, cities are experiencing even greater temperatures due to the urban heat island effect, which is the trapping of heat in “gray” urban infrastructure. Cities are combatting this with green infrastructure (GI) initiatives, such as the Department of Environmental Protection (DEP) GI initiative in New York City. However, these programs are often [...]
Modifications to Internal Tide Conversion Parameterizations and Implementation into Barotropic Ocean Models
Published: 2018-08-15
Subjects: Civil and Environmental Engineering, Engineering, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Parameterization of the tidal energy conversion from barotropic to baroclinic modes through internal tide generation over rough and steep submarine topography is a necessary dissipative force for barotropic ocean models. We present and unify two forms of parameterizations that differ by assuming that wave generation is either only due to the local topographic features, or that it includes the [...]
A network scale, intermediate complexity model for simulating channel evolution over years to decades
Published: 2018-07-03
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Physical Sciences and Mathematics
Excessive river erosion and sedimentation threatens critical infrastructure, degrades aquatic habitat, and impairs water quality. Tools for predicting the magnitude of erosion, sedimentation, and channel evolution processes are needed for effective mitigation and management. We present a new numerical model that simulates coupled river bed and bank erosion at the watershed scale. The model uses [...]
Evaluation of open-access global digital elevation models (AW3D30, SRTM and ASTER) for flood modelling purposes
Published: 2018-06-25
Subjects: Aerospace Engineering, Civil and Environmental Engineering, Computational Engineering, Computer Engineering, Earth Sciences, Engineering, Environmental Sciences, Hydraulic Engineering, Hydrology, Life Sciences, Physical Sciences and Mathematics, Water Resource Management
Digital Elevation Models (DEM) are a key piece of information for the accurate representation of topographic controls exerted in hydrologic and hydraulic models. Many practitioners rely on open-access global datasets usually obtained from space-borne survey due to the cost and sparse coverage of sources of higher resolution. In may 2016 the Japan Aerospace eXploration Agency publicly released an [...]
Surface albedo as a proxy for land-cover clearing in seasonally dry forests: evidence from the Brazilian Caatinga
Published: 2018-05-16
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Natural Resources and Conservation, Other Environmental Sciences, Physical Sciences and Mathematics
Ongoing increase in human and climate pressures, in addition to the lack of monitoring initiatives, makes the Caatinga one of the most vulnerable forests in the world. The Caatinga is located in the semi-arid region of Brazil and its vegetation phenology is highly dependent on precipitation, which has a high spatial and temporal variability. Under these circumstances, satellite image-based [...]
Rainfall-Runoff modelling using Long Short-Term Memory (LSTM) networks
Published: 2018-05-01
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Hydrology, Physical Sciences and Mathematics
Rainfall-runoff modelling is one of the key challenges in the field of hydrology. Various approaches exist, ranging from physically based over conceptual to fully data driven models. In this paper, we propose a novel data driven approach, using the Long-Short-Term-Memory (LSTM) network, a special type of recurrent neural networks. The advantage of the LSTM is its ability to learn long-term [...]
Optimising tidal range power plant operation
Published: 2017-12-11
Subjects: Civil and Environmental Engineering, Civil Engineering, Computational Engineering, Electrical and Computer Engineering, Engineering, Hydraulic Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Power and Energy
Tidal range power plants represent an attractive approach for the large-scale generation of electricity from the marine environment. Even though the tides and by extension the available energy resource are predictable, they are also variable in time. This variability poses a challenge regarding the optimal transient control of power plants. Here we consider simulation methods which include the [...]
Comparison of 0-D, 1-D and 2-D model capabilities for tidal range energy resource assessments
Published: 2017-11-22
Subjects: Civil and Environmental Engineering, Computational Engineering, Earth Sciences, Electrical and Computer Engineering, Engineering, Environmental Sciences, Hydraulic Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Power and Energy
Tidal range energy projects present an attractive means for the predictable and large-scale generation of electricity from the marine environment. In particular, proposals are under consideration in UK waters, with their feasibility currently being under high levels of scrutiny. This is due to a combination of potential environmental and socio-economic impacts that are challenging to quantify in [...]
A comparison of GPS, VLBI and model estimates of ocean tide loading displacements
Published: 2017-11-13
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Sciences, Geophysics and Seismology, Other Civil and Environmental Engineering, Other Earth Sciences, Physical Sciences and Mathematics
In recent years, Ocean Tide Loading Displacements (OTLD) have been measured using the Global Positioning System (GPS) and Very Long Baseline Interferometry (VLBI). This study assesses the accuracy of GPS measurements of OTLD by comparison with VLBI measurements and estimates derived from numerical ocean tide models. A daily precise point positioning (PPP) analysis was carried out on ~11 years of [...]
GPS sidereal filtering: coordinate- and carrier-phase-level strategies
Published: 2017-11-13
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Other Civil and Environmental Engineering, Other Earth Sciences, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics
Multipath error is considered one of the major errors affecting GPS observations. One can benefit from the repetition of satellite geometry approximately every sidereal day, and apply filtering to help minimize this error. For GPS data at 1 second interval processed using a double-difference strategy, using the day-to-day coordinate or phase residual autocorrelation determined with a 10 hour [...]