Preprints
Filtering by Subject: Environmental Sciences
Towards machine ecoregionalization of Earth’s landmass using pattern segmentation method
Published: 2018-02-15
Subjects: Categorical Data Analysis, Computer Sciences, Earth Sciences, Environmental Sciences, Geographic Information Sciences, Geography, Numerical Analysis and Scientific Computing, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Statistics and Probability
We present and evaluate a quantitative method for delineation of ecophysigraphic regions throughout the entire terrestrial landmass. The method uses the new pattern-based segmentation technique which attempts to emulate the qualitative, weight-of-evidence approach to a delineation of ecoregions in a computer code. An ecophysiographic region is characterized by homogeneous physiography defined by [...]
Global inventory of landscape patterns and latent variables of landscape spatial configuration
Published: 2018-02-15
Subjects: Biodiversity, Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Sciences, Geographic Information Sciences, Geography, Life Sciences, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science
We present a regionalization of the entire Earth’s landmass into land units of homogeneous landscape patterns. The input to the regionalization is a high resolution Global Land Cover (GLC) dataset. The GLC is first divided into local landscapes – small non-overlapping square blocks of GLC cells. These blocks are agglomerated into much larger land units using a pattern-based segmentation [...]
Distributions of geohopanoids in peat: implications for the use of hopanoid-based proxies in natural archives
Published: 2018-02-04
Subjects: Biogeochemistry, Chemistry, Earth Sciences, Environmental Sciences, Geochemistry, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics
Hopanoids are pentacyclic triterpenoids produced by a wide range of bacteria. Within modern settings, hopanoids mostly occur in the biological 17β,21β(H) configuration. However, in some modern peatlands, the C31 hopane is present as the thermally-mature 17α,21β(H) stereoisomer. This has traditionally been ascribed to isomerisation at the C-17 position catalysed by the acidic environment. However, [...]
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 [...]
Leaf trait acclimation amplifies simulated climate warming in response to elevated carbon dioxide
Published: 2018-01-10
Subjects: Earth Sciences, Ecology and Evolutionary Biology, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics, Physiology, Plant Sciences
Vegetation modifies Earth’s climate by controlling the fluxes of energy, carbon, and water. Of critical importance is a better understanding of how vegetation responses to climate change will feedback on climate. Observations show that plant traits respond to elevated carbon dioxide concentrations. These plant trait acclimations can alter leaf area and thus productivity and surface energy fluxes. [...]
River Restoration Design Framework
Published: 2018-01-10
Subjects: Environmental Sciences, Natural Resources and Conservation, Physical Sciences and Mathematics
This preprint provides a design framework for river restoration and enhancement efforts. The preprint will be of interest to watershed stakeholder groups, jurisdictional permitting staff and river restoration practitioners.
Analysis of miscellaneous non-ambergris organic jetsam beach deposits
Published: 2018-01-05
Subjects: Environmental Monitoring, Environmental Sciences, Physical Sciences and Mathematics
The analysis of a number of ad hoc samples of organic beach jetsam by Fourier transform infrared spectroscopy (FTIR), gas chromatography (GC), high temperature GC (HTGC), GC-mass spectrometry (GC-MS) HTGC-MS and derivatisation, is described. Many of these samples were found by members of the public and handed in for analysis in the hope that the material was ambergris. Jetsam ambergris is [...]
Estimating regional flood discharge during Palaeocene-Eocene global warming (submitted)
Published: 2018-01-04
Subjects: Climate, Earth Sciences, Environmental Sciences, Geology, Geomorphology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sedimentology, Stratigraphy
Among the most urgent challenges in future climate change scenarios is accurately predicting the magnitude at which precipitation extremes will intensify. Analogous changes have been reported for an episode of millennial scale 5°C warming termed the Palaeocene-Eocene Thermal Maximum (PETM; 56 Ma), providing independent constraints on hydrological response to global warming. However, quantifying [...]
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 [...]
Lake sediment records of persistent organic pollutants and polycyclic aromatic hydrocarbons in Southern Siberia mirror the changing fortunes of the Russian economy over the past 70 years
Published: 2017-12-18
Subjects: Chemistry, Ecology and Evolutionary Biology, Environmental Chemistry, Environmental Sciences, Life Sciences, Physical Sciences and Mathematics, Terrestrial and Aquatic Ecology
Persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) have previously been detected in the surface sediments, water, and endemic organisms of Lake Baikal, a UNESCO World Heritage Site. The Selenga River is the primary source of freshwater to Lake Baikal, and transports pollutants accumulating in the Selenga River basin to the lake. Sources of POPs and PAHs in the [...]
The joint influence of break and noise variance on the break detection capability in time series homogenization
Published: 2017-12-15
Subjects: Climate, Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Instrumental climate records of the last centuries suffer from multiple breaks due to relocations and changes in measurement techniques. These breaks are detected by relative homogenization algorithms using the difference time series between a candidate and a reference. Modern multiple changepoint methods use a decomposition approach where the segmentation explaining most variance defines the [...]
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 [...]
Estimating geological CO2 storage security to deliver on climate mitigation
Published: 2017-12-04
Subjects: Earth Sciences, Environmental Sciences, Natural Resources Management and Policy, Physical Sciences and Mathematics
Carbon capture and storage (CCS) can help nations meet their Paris CO2 reduction commitments cost-effectively. However, lack of confidence in geologic CO2 storage security remains a barrier to CCS implementation. Here we present a numerical program that calculates CO2 storage security and leakage to the atmosphere over 10,000 years. This combines quantitative estimates of geological subsurface [...]
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 [...]