Preprints
Filtering by Subject: Hydrology
River dissolved inorganic carbon losses from the Andes to lowland Amazon via cryptic sedimentary exchange processes
Published: 2026-08-05
Subjects: Biogeochemistry, Earth Sciences, Geochemistry, Geomorphology, Hydrology
River carbon transfers and associated greenhouse gas emissions are a major component of the carbon cycle. Proposals to use rivers and their catchments to increase carbon dioxide (CO2) drawdown, by enhanced rock weathering and river alkalinity enhancement, require secure delivery of dissolved inorganic carbon (DIC) and increased cation loads (e.g. Ca2+) to the ocean. Here we explore the fate of [...]
Global Flood Mapper v2: Open-Access Flood Mapping and Exposure Assessment with Sentinel-1 SAR
Published: 2026-07-31
Subjects: Environmental Monitoring, Hydrology
We present Global Flood Mapper v2 (GFM v2), which adds flood depth estimation, on-demand GeoTIFF export, cloud-based impact assessment against high-resolution land cover and five global population datasets to quantify exposure uncertainty, and parameter-encoded URLs for reproducibility and sharing. Its predecessor, GFM v1, was already an open-access, globally operational web portal for rapid, [...]
Stress-Conditioned Lightweight Flash-Drought Detection in the US Corn Belt Using MODIS NDVI and ERA5-Land
Published: 2026-07-29
Subjects: Hydrology, Meteorology
Flash-drought monitoring by classical indices averages predictive signal across calm and stressed years, blunting the signal exactly where it matters. We show empirically that the coupling between precipitation, soil moisture, vapor pressure deficit (VPD), and NDVI is stress-conditional: the hydrological pathway is visible when vegetation is already under stress (Spearman rho of about 0.18 for [...]
Detecting illegal water abstractions using Earth Observation and artificial intelligence: challenges, research gaps, and future directions
Published: 2026-07-28
Subjects: Artificial Intelligence and Robotics, Environmental Monitoring, Hydrology, Natural Resources Management and Policy, Remote Sensing, Water Resource Management
Water scarcity and unsustainable withdrawals are major environmental challenges, particularly in semi-arid and Mediterranean regions where agriculture places strong pressure on limited hydrological resources. Illegal or unreported water abstractions intensify these pressures by undermining ecosystem stability, policy compliance, and long-term water security. Although Earth Observation (EO) and [...]
Connectivity effects on fluid age and residence time distributions in two- and three-dimensional pore networks
Published: 2026-07-27
Subjects: Biogeochemistry, Earth Sciences, Hydrology, Physical Sciences and Mathematics
Pore-scale simulations are often run on a single plane cut from a three-dimensional image, because resolving the whole pore space is expensive. This study asks what that shortcut costs. What is at stake is the distribution of fluid ages, and above all its long tail, because that tail is what slow reactions respond to. We computed the distribution directly from the flow field, by labeling the [...]
Reconstructing age and reactivity distributions from the moments carried by central-moment transport models
Published: 2026-07-26
Subjects: Biogeochemistry, Earth Sciences, Hydrology, Physical Sciences and Mathematics
A central-moment transport model follows a property that varies across a population, such as the age of water parcels or the decay rate of organic-matter particles. Instead of storing the whole distribution of that property, it keeps only a few summary numbers, the moments, and moves those through the model. But the distribution itself is usually what a scientist wants, so it has to be rebuilt [...]
Mechanical Association between Pressure Wave Propagation Time and Constitutive Parameter Damage in Porous Media: Theoretical Derivation and Sensitivity Analysis
Published: 2026-07-16
Subjects: Engineering Mechanics, Geology, Geophysics and Seismology, Geotechnical Engineering, Hydraulic Engineering, Hydrology, Physics, Soil Science
The propagation time of pressure waves in porous media carries critical information about the constitutive parameters of the medium. This study rigorously derives the mechanical relationship between the lag time of pressure wave and the hydraulic parameters of porous media based on the diffusion wave equation. The lag time is shown to be a direct functional of the hydraulic conductivity and [...]
CSUFlow25: Colorado Streamflow Ungaged Prediction Models
Published: 2026-07-07
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics, Water Resource Management
CSUFlow25 is an updated set of statistical models for predicting streamflow in ungaged basins in Colorado, USA. It builds on the earlier CSUFlow18 models (Eurich et al., 2021) by extending the streamflow record from water years 2001–2018 to 2001–2024, expanding the pool of candidate predictor variables, and increasing the number of streamflow metrics predicted. Models were developed from a [...]
SWMMCanada: An Open-Source Service for Generating Ready-to-Run Urban Drainage Models Across Canada
Published: 2026-07-03
Subjects: Civil and Environmental Engineering, Computational Engineering, Engineering, Environmental Engineering, Geotechnical Engineering, Hydrology, Software Engineering
Urban stormwater modelling is often slowed more by data preparation than by the simulation itself, because rainfall, terrain, land cover, soil, and pipe network data usually come from different agencies, formats, projections, and data structures. This software paper presents SWMMCanada, an open source and standardized model building service that makes Canadian urban hydrological modelling easier [...]
Quantifying Watershed Criticality via Deep Learning and Explainable AI for Groundwater Resilience
Published: 2026-07-02
Subjects: Civil and Environmental Engineering, Earth Sciences, Environmental Engineering, Environmental Sciences, Hydrology, Water Resource Management
Groundwater is a vital freshwater resource that supports drinking water supply, agricultural sustainability, ecosystem functioning, and drought resilience. As water scarcity and climate change impacts intensify, sustainable groundwater management plays an important role in groundwater management, with groundwater storage (GWS) acting as a key indicator of groundwater resilience. This study [...]
Merge Satellite and Gauge Daily Precipitation Data for Areas with Sparse-Gauge and Rugged Terrain: A High-Accuracy Gridded Dataset CGS01 (2000-2024) across China
Published: 2026-07-02
Subjects: Earth Sciences, Hydrology, Physical Sciences and Mathematics
High-precision quantiffcation of regional precipitation is the foundation of watershed water balance analysis and water resources management. However, current approaches are hindered by methodological diversity and inconsistent results, with limited accuracy, especially in gauge-sparse regions and areas with drastic topographic relief. This study proposes a dual thin-plate spline (TPS) fusion [...]
Measurement and Tracking of Blowing and Falling Snow Particles Using an Automotive 1550 nm LiDAR
Published: 2026-06-26
Subjects: Atmospheric Sciences, Fresh Water Studies, Glaciology, Hydrology, Meteorology
The prevalence and affordability of fast-scanning commercially available LiDARs are increasing due to the rapid expansion of the autonomous vehicle industry. These LiDAR units can provide >1 Hz measurements of millions of laser reflections at ranges of hundreds of meters with high precision. In this study we investigate the often overlooked 1550 nm wavelength LiDAR for measurements of airborne [...]
Probabilistic Regional Conditioning of Natural Hazard Loss Models
Published: 2026-06-25
Subjects: Environmental Studies, Hydrology, Risk Analysis
Natural hazard risk models underpin decisions from insurance pricing to infrastructure investment, yet their accuracy depends on vulnerability functions rarely calibrated to local conditions. The most accurate vulnerability functions capture regional building characteristics through multi-variable models or large engineering-based loss-function databases, but need detailed asset-level data that [...]
Where to Watch the Water: Multi-Sensor Network Design Optimization for Inland Flood Detection
Published: 2026-06-23
Subjects: Earth Sciences, Environmental Sciences, Geomorphology, Hydrology, Physical Sciences and Mathematics, Water Resource Management
Inland flood detection is often constrained less by sensor availability than by where sensors are placed along branching river networks, especially in ungauged headwaters where floods often initiate. We present a three-phase, decisionfocused framework for designing basin-by-basin multi-sensor flood detection networks that coordinate water-level, discharge, and camera sensors while explicitly [...]
Tectonic pump closes the evolutionary loop for long-buried subseafloor microbes
Published: 2026-06-22
Subjects: Biogeochemistry, Geophysics and Seismology, Hydrology, Tectonics and Structure
Deep marine sediments host one of Earth’s largest microbial biospheres, yet most cells in this environment persist in a non-growing state for thousands to millions of years beneath kilometers of sediment. For natural selection to favor such extraordinary long-term survival, a mechanism must exist that is capable of returning buried living populations to near-surface environments, where [...]