Preprints
Filtering by Subject: Civil and Environmental Engineering
Hydrodynamic control of gas-exchange velocity in small streams
Published: 2019-03-02
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Sciences, Fluid Dynamics, Hydraulic Engineering, Physical Sciences and Mathematics, Physics, Planetary Sciences
Gas exchange is a critical component of any biogeochemical mass balance model of dissolved gases in aquatic systems, yet the magnitude and drivers of spatial and temporal variations of air-water exchange rates in shallow streams are poorly understood. We investigated the relationships between gas exchange velocity of carbon dioxide and methane and flow hydraulics at different sections along a [...]
Heavy rainfall in Paraguay during the 2015-2016 austral summer: causes and sub-seasonal-to-seasonal predictive skill
Published: 2019-02-11
Subjects: Atmospheric Sciences, Civil and Environmental Engineering, Climate, Earth Sciences, Engineering, Environmental Engineering, Environmental Sciences, Hydrology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Water Resource Management
During the austral summer 2015/16, severe flooding displaced over 170 000 people on the Paraguay River system in Paraguay, Argentina, and southern Brazil. These floods were driven by repeated heavy rainfall events in the lower Paraguay River basin. Alternating sequences of enhanced moisture inflow from the South American low-level jet and local convergence associated with baroclinic systems were [...]
Utilising the flexible generation potential of tidal range power plants to optimise economic value
Published: 2019-01-08
Subjects: Civil and Environmental Engineering, Computational Engineering, Engineering, Hydraulic Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Tidal range renewable power plants have the capacity to deliver predictable energy to the electricity grid, subject to the known variability of the tides. Tidal power plants inherently feature advantages that characterise hydro-power more generally, including a lifetime exceeding alternative renewable energy technologies and relatively low Operation & Maintenance costs. Nevertheless, the [...]
Intensity-Duration-Frequency curves at the global scale
Published: 2018-12-18
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Sciences, Hydraulic Engineering, Hydrology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Water Resource Management
Intensity-Duration-Frequency (IDF) curves usefully quantify extreme precipitation over various durations and return periods for engineering design. Unfortunately, sparse, infrequent or short observations hinder the creation of robust IDF curves in many locations. This paper presents the first global, multi-temporal (1 to 360 hours) dataset of Generalized Extreme Value (GEV) parameters at 31 km [...]
Rapid and accurate estimates of streamflow depletion caused by groundwater pumping using analytical depletion functions
Published: 2018-11-12
Subjects: Civil and Environmental Engineering, Civil Engineering, Earth Sciences, Engineering, Environmental Sciences, Hydrology, Natural Resources Management and Policy, Physical Sciences and Mathematics, Water Resource Management
Reductions in streamflow due to groundwater pumping (‘streamflow depletion’) can negatively impact water users and aquatic ecosystems but are challenging to estimate due to the time and expertise required to develop numerical models often used for water management. Here, we develop analytical depletion functions, which are simpler approaches consisting of (i) stream proximity criteria which [...]
Flow-Substrate Interactions in Aggrading and Degrading Submarine Channels
Published: 2018-10-24
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Geology, Geomorphology, Other Civil and Environmental Engineering, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Connecting real time measurements of current-bed interactions to the temporal evolution of submarine channels can be extremely challenging in natural settings. We present a suite of physical experiments that offer insight into the spectrum of interactions between turbidity currents and their channels, from (i) detachment-limited erosion to (ii) transport-limited erosion to (iii) pure deposition. [...]
Modeling the effects of future urban planning scenarios on the Urban Heat Island in a complex region
Published: 2018-10-02
Subjects: Civil and Environmental Engineering, Construction Engineering and Management, Engineering, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Because of the global warming, urban planning strategies must be investigated to reduce the building energy consumption and increase the thermal comfort in cities. In the framework of Energy Strategy 2050 of Switzerland, this research aim to highlight the impact of future climate change on urban planning and proposes strategies to help urban planners and policymakers face this new challenge [...]
Vulnerability of Louisiana’s coastal wetlands to present-day rates of relative sea-level rise
Published: 2018-10-01
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Engineering, Environmental Monitoring, Environmental Sciences, Geology, Geomorphology, Hydrology, Natural Resources Management and Policy, Physical Sciences and Mathematics, Risk Analysis, Sedimentology, Soil Science, Stratigraphy, Sustainability
Coastal Louisiana has lost about 5,000km2 of wetlands over the past century and concern exists whether remaining wetlands will persist while facing some of the world’s highest rates of relative sea-level rise (RSLR). Here we analyse an unprecedented data set derived from 274 rod surface-elevation table-marker horizon stations, to determine present-day surface-elevation change, vertical accretion [...]
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: 2018-09-24
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 [...]