Preprints
There are 7655 Preprints listed.
Spatiotemporal variations in trawling intensity in the German Baltic Sea Basins based on bathymetric data
Published: 2026-08-20
Subjects: Earth Sciences
Bottom trawling is the largest source of anthropogenic seafloor disturbance globally, yet spatiotemporal variations are poorly constrained in most regions due to non-reporting or low-resolution fishing effort data. To overcome this gap in knowledge, we use a U-Net convolutional neural network to segment trawl marks across approximately 1,069 square kilometers of seafloor in the German sector of [...]
Abiotic Oxygen and the Limits of Earth Analogy in Exoplanet Biosignature Interpretation
Published: 2026-08-20
Subjects: Physical Sciences and Mathematics
The detection of atmospheric oxygen on a rocky exoplanet is widely regarded as a strong indicator of biological activity. This expectation derives from a single observational precedent: Earth. We argue that this extrapolation conflates two epistemologically distinct categories of knowledge — universal physical laws, which apply to any rocky planet under any conditions, and contingent terrestrial [...]
A Unified and Scalable Framework for the Comprehensive Evaluation of Hydrological Model Behavior and Structural Diagnostics
Published: 2026-08-20
Subjects: Civil and Environmental Engineering, Environmental Engineering, Hydraulic Engineering, Statistical Methodology, Statistical Models
Robust evaluation of hydrological models requires assessing not only predictive accuracy, but also uncertainty behavior and structural realism. This study introduces the Hydrological Model Evaluation System (HyMES), a unified framework that organizes deterministic, probabilistic, and structural diagnostics, including dynamic hysteresis analysis, into a coherent, station level evaluation workflow. [...]
A heuristic approach to structural consistency of a horizon surface with tectonic faults based on Mallet's discrete model
Published: 2026-08-20
Subjects: Geology, Geomorphology, Geophysics and Seismology, Mining Engineering, Theory and Algorithms
The paper addresses the problem of automating the consistency process between reflecting horizon surfaces and the network of tectonic faults in the construction of three-dimensional digital geological models within the explicit (surface-based) approach. The problem is formalized on the basis of Mallet's discrete model (Discrete Smooth Interpolation, DSI). It is shown that the classical [...]
Reconstructing the P-T-t evolution recorded in garnet through growth and multicomponent diffusion modelling
Published: 2026-08-20
Subjects: Earth Sciences, Geochemistry, Geology
Interpreting the P –T evolution of a region recorded in garnet requires understanding of how the major elements in garnet (Fe, Mg, Mn and Ca) are modified by diffusion. We present an integrated approach that combines thermodynamic modelling with MAGEMin and multicomponent diffusion modelling using UWDiffusion, built on underworld3, to constrain the P–T–t evolution of a garnet pyroxenite from the [...]
Satellite-Based Assessment of Terrestrial Water Storage Change and Groundwater Stress in Zhob District, Balochistan
Published: 2026-08-20
Subjects: Earth Sciences, Environmental Sciences
Groundwater underpins domestic supply and irrigated agriculture across much of Balochistan, Pakistan, and satellite-based subsidence studies have documented severe groundwater-related stress around Quetta, Gulistan, Pishin, Mastung, and Kalat districts. Zhob District, in northern Balochistan, is comparably dependent on tubewell and karez irrigation but has not been covered by any published [...]
Wildfire severity reshapes remotely sensed surface temperature and vegetation phenology in a Western Cascades forest ecosystem
Published: 2026-08-20
Subjects: Life Sciences
Wildfire reorganizes forests by altering canopy structure, surface energy balance, vegetation activity, and microclimate. However, these effects remain difficult to quantify across seasons, times of day, burn severities, and complex terrain. We used the 2023 Lookout Fire at the H.J. Andrews Experimental Forest, Oregon, to test how fire severity altered coupling between surface temperature and [...]
Explicit Structural Modeling of Geological Horizons Near Fault Networks
Published: 2026-08-20
Subjects: Engineering, Physical Sciences and Mathematics
This article extends the approach of constructing a geological horizon surface near a single tectonic fault to the case of a system of arbitrary, including intersecting, faults. The generalization requires solving four subtasks: formalization of the fault system as a simplicial complex, construction of the modeling domain as a gamma-neighborhood of the cut graph on the triangulation, replacement [...]
What Can We Learn from a Reduced-Dimensional Groundwater Representation for Diagnosing Groundwater–Land Interactions? Insights from the Water Table Ratio
Published: 2026-08-20
Subjects: Engineering, Physical Sciences and Mathematics
Groundwater exerts an important control on land–atmosphere interactions, yet its explicit representation in Earth system models remains computationally prohibitive. Reduced-dimensional metrics, such as the Water Table Ratio (WTR), have been proposed to represent groundwater influences on land–atmosphere interactions. However, their uncertainty, classification stability, and correspondence with [...]
Coupling Chemistry and Machine Learning Across the Lithium Supply Chain: Resource Geochemistry, Extraction, Separation, and Recycling
Published: 2026-08-20
Subjects: Engineering
Lithium supply must expand sharply over the coming decades to support the electrification of transport and the growth of stationary energy storage. At almost every stage the governing chemical challenge is the same: concentrating and separating Li⁺ from chemically similar competing ions at acceptable economic and environmental cost. This review examines the supply chain through two interconnected [...]
ECMWF SEAS5 Seasonal Precipitation Outlook and Hydrological-Hydrogeological Assessment for the Middle East: August 2026-January 2027
Published: 2026-08-16
Subjects: Agriculture, Earth Sciences, Environmental Sciences, Food Science, Higher Education, Oceanography and Atmospheric Sciences and Meteorology, Risk Analysis
This preprint presents a regional hydrological and hydrogeological interpretation of the ECMWF SEAS5 System 51 ensemble-mean precipitation forecast initialized on 1 August 2026 for the Middle East and adjacent portions of the analysis domain. The supplied NetCDF field is time-mean total precipitation rate (tprate; m s^-1), converted to monthly precipitation depth (mm/month) using the actual [...]
Mapping Ice Slabs over Antarctic Ice Shelves using Quad-Polarization L-band Radar Backscatter
Published: 2026-08-16
Subjects: Physical Sciences and Mathematics
Nearly 3 months of enhanced-resolution, quad-polarization, L-band (1.26 GHz) radar backscatter (σo) image time series are used to map the ice slab extent over the percolation facies of Antarctic ice shelves for the first time from space. Distinctive spatial trends in σo, incidence angle, and polarization signatures mapped via principal component analysis (PCA) are used to develop a [...]
Counting the Solomon Islands: How Many Islands Does the Archipelago Actually Contain?
Published: 2026-08-16
Subjects: Physical and Environmental Geography, Remote Sensing, Spatial Science
Solomon Islands is widely reported to comprise approximately 900--1,000 islands, a figure repeated across government, tourism, and encyclopedic sources without a traceable methodology. We re-examine this figure using two independent, reproducible geospatial datasets: the USGS/Esri/UNEP-WCMC Global Islands database (30 m Landsat-derived classification) and OpenStreetMap (OSM) land polygon data [...]
Flooded Rivers, Drying Wetlands, Vanishing Tributaries: Hydrological Paradox of the East Ganga Plains
Published: 2026-08-16
Subjects: Environmental Monitoring, Geomorphology, Hydrology, Natural Resources Management and Policy, Physical Sciences and Mathematics, Sustainability, Water Resource Management
The East Ganga Plains (EGP) present a striking hydrological paradox: while embanked rivers flood with increasing magnitude, adjacent wetlands and groundwater-fed streams are desiccating, and aquifer storage is declining. Using satellite remote sensing and gravimetry, we document that: (i) wetlands exhibit significant water-cover loss despite stable monsoon rainfall; (ii) small rivers and [...]
PyRiverShift: A Gaussian Transect Decomposition Framework for Quantifying Sub-Pixel Lateral Channel Mobility
Published: 2026-08-16
Subjects: Applied Statistics, Earth Sciences, Environmental Indicators and Impact Assessment, Environmental Monitoring, Geomorphology, Hydrology, Physical Sciences and Mathematics, Sedimentology, Water Resource Management
Along many rivers, lateral channel mobility is a key process, yet quantification from freely available multi-decadal 30 m Landsat imagery is constrained by low pixel resolution relative to channel width. We introduce PyRiverShift, a sensor-agnostic spectral decomposition framework. PyRiverShift fits a 1-D Gaussian to NDWI profiles along valley-perpendicular transects, recovering sub-pixel channel [...]