Preprints
Filtering by Subject: Hydrology
River deltas as Multiplex networks: A framework for studying multi-process multi-scale connectivity via coupled-network theory
Published: 2018-04-13
Subjects: Applied Mathematics, Dynamic Systems, Earth Sciences, Environmental Sciences, Geomorphology, Hydrology, Mathematics, Non-linear Dynamics, Physical Sciences and Mathematics, Physics, Statistical, Nonlinear, and Soft Matter Physics
Transport of water, nutrients or energy fluxes in many natural or coupled human-natural systems occurs along different pathways that often have a wide range of transport timescales and might exchange fluxes with each other dynamically (e.g., surface-subsurface). Understanding this type of transport is key to predicting how landscapes will change under changing forcing. Here, we present a general [...]
Using climate to relate water-discharge and area in modern and ancient catchments
Published: 2018-04-13
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Models relating sediment-supply to catchment-properties are important in order to use the geological record to deduce landscape evolution and the interplay between tectonics and climate. Water-discharge (Qw) is an important factor in the widely used BQwART-model of Syvitski and Milliman (2007), which relates sediment load to a set of measureable catchment parameters. Although many of the factors [...]
Reporting negative results to stimulate experimental hydrology
Published: 2018-03-13
Subjects: Earth Sciences, Hydrology, Life Sciences, Physical Sciences and Mathematics
Experimental work in hydrology is in decline. Based on a community survey, Blume et al. showed that the hydrological community associates experimental work with greater risks. One of the main issues with experimental work is the higher chance on negative results (defined here as when the expected or wanted result was not observed despite careful experimental design, planning and execution), [...]
Climatic influences on the offset between d18O of cave drip waters and precipitation inferred from global monitoring data
Published: 2018-03-09
Subjects: Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Geochemistry, Hydrology, Physical Sciences and Mathematics, Speleology
We present a meta-analysis of data from 22 caves and 96 drip sites from 4 continents where both the cave drip water d18O and the weighted mean d18O of precipitation have been measured. Drip water d18O is similar to the weighted mean d18O of precipitation (within ± 0.3 ‰) for sites where mean annual temperature (MAT) is less than 15 °C (85% of drips where MAT < 15 °C) and an aridity index [...]
Tracking Groundwater Levels using the Ambient Seismic Field
Published: 2018-02-27
Subjects: Earth Sciences, Geophysics and Seismology, Hydrology, Physical Sciences and Mathematics
Aquifers are vital groundwater reservoirs for residential, agricultural, and industrial activities worldwide. Tracking their state with high temporal and spatial resolution is critical for water resource management at the regional scale yet is rarely achieved from a single dataset. Here, we show that variations in groundwater levels can be mapped using perturbations in seismic velocity (dv/v). [...]
Groundwater controls on post-fire permafrost thaw: Water and energy balance effects
Published: 2018-02-22
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics
Fire frequency and severity are increasing in high latitude regions, but the degree to which groundwater flow impacts the response of permafrost to fire remains poorly understood. Here, we use the Anaktuvuk River Fire (Alaska, USA) as an example for simulating groundwater-permafrost interactions following fire. We identify key thermal and hydrologic parameters controlling permafrost response to [...]
Selection of hydrological signatures for large-sample hydrology
Published: 2018-02-12
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
Hydrological signatures are now used for a wide range of purposes, including catchment classification, process exploration and hydrological model calibration. The recent boost in the popularity and number of signatures has however not been accompanied by the development of clear guidance on signature selection, meaning that signature selection is often arbitrary. Here we use three complementary [...]
Groundwater pumping impacts on real stream networks: testing the performance of simple management tools
Published: 2018-02-02
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics, Water Resource Management
Quantifying reductions in streamflow due to groundwater pumping (‘streamflow depletion’) is essential for conjunctive management of groundwater and surface water resources. Analytical models are widely used to estimate streamflow depletion but include potentially problematic assumptions such as simplified stream-aquifer geometry and rely on largely untested depletion apportionment equations to [...]
Impacts of land-use and land-cover change on stream hydrochemistry in the Cerrado and Amazon biomes
Published: 2018-01-28
Subjects: Chemistry, Computer Sciences, Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Monitoring, Environmental Sciences, Fresh Water Studies, Geography, Hydrology, Natural Resources and Conservation, Oceanography and Atmospheric Sciences and Meteorology, Physical and Environmental Geography, Physical Sciences and Mathematics, Physics, Social and Behavioral Sciences, Soil Science
Studies on the impacts of land-use and land-cover change on stream hydrochemistry in active deforestation zones of the Amazon agricultural frontier are limited and have often used low-temporal-resolution datasets. Moreover, these impacts are not concurrently assessed in well-established agricultural areas and new deforestations hotspots. We aimed to identify these impacts using an experimental [...]
Drought Conditions Maximize the Impact of High-Frequency Flow Variations on Thermal Regimes and Biogeochemical Function in the Hyporheic Zone
Published: 2018-01-16
Subjects: Biogeochemistry, Earth Sciences, Hydrology, Physical Sciences and Mathematics
Anthropogenic activities, especially dam operations, often induce larger and more frequent stage fluctuations than those occurring in natural rivers. However, long-term impacts of such flow variations on thermal and biogeochemical dynamics of the associated hyporheic zone (HZ) are poorly understood. In this study, we built a heterogeneous, two-dimensional, thermo-hydro-biogeochemical model for a [...]
The role of glacier retreat for Swiss hydropower production
Published: 2017-12-22
Subjects: Earth Sciences, Engineering, Environmental Sciences, Glaciology, Hydrology, Natural Resource Economics, Natural Resources Management and Policy, Physical Sciences and Mathematics, Sustainability, Water Resource Management
High elevation or high latitude hydropower production (HP) strongly relies on water resources that are influenced by glacier melt and are thus highly sensitive to climate warming. Despite of the wide-spread glacier retreat since the development of HP infrastructure in the 20th century, little quantitative information is available about the role of glacier mass loss for HP. We provide the first [...]
Multiphase flow characteristics of heterogeneous rocks from CO2 storage reservoirs in the United Kingdom
Published: 2017-12-08
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Oil, Gas, and Energy, Physical Sciences and Mathematics
We have studied the impact of heterogeneity on relative permeability and residual trapping for rock samples from the Bunter sandstone of the UK Southern North Sea, the Ormskirk Sandstone of the East Irish Sea, and the Captain Sandstone of the UK Northern North Sea. Reservoir condition CO2-brine relative permeability measurements were made while systematically varying the ratio of viscous to [...]
Characterising Drainage Multiphase Flow in Heterogeneous Sandstones
Published: 2017-12-07
Subjects: Earth Sciences, Engineering, Hydrology, Physical Sciences and Mathematics
In this work, we analyse the characterisation of drainage multiphase flow properties on heterogeneous rock cores using a rich experimental dataset and mm-m scale numerical simulations. Along with routine multiphase flow properties, 3D sub-metre scale capillary pressure heterogeneity is characterised by combining experimental observations and numerical calibration, resulting in a 3D numerical [...]
Non-crossing nonlinear regression quantiles by monotone composite quantile regression neural network, with application to rainfall extremes
Published: 2017-12-05
Subjects: Artificial Intelligence and Robotics, Climate, Computer Sciences, Earth Sciences, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Statistical Models, Statistics and Probability
The goal of quantile regression is to estimate conditional quantiles for specified values of quantile probability using linear or nonlinear regression equations. These estimates are prone to "quantile crossing", where regression predictions for different quantile probabilities do not increase as probability increases. In the context of the environmental sciences, this could, for example, lead to [...]
A new global mode of Earth deformation: seasonal cycle detected
Published: 2017-11-14
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Geophysics and Seismology, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Other Environmental Sciences, Other Oceanography and Atmospheric Sciences and Meteorology, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics
We have detected a global mode of Earth deformation that is predicted by theory. Precise positioning of GPS sites distributed worldwide reveals that in February to March the northern hemisphere compresses (and the southern hemisphere expands), such that sites near the North Pole move downward by 3.0 mm, and sites near the equator are pulled northwards by 1.5 mm. The opposite pattern of [...]