Preprints
Filtering by Subject: Hydrology
Hydroelectric Regulation Decouples Arctic Silica Delivery from the Diatom Bloom: A Climate-Independent Causal Attribution Across Twenty Subarctic Rivers
Published: 2026-05-23
Subjects: Earth Sciences, Hydrology, Oceanography, Physical Sciences and Mathematics
Large subarctic rivers deliver most of their dissolved nutrients during the spring freshet, in approximate phase with the ice-edge diatom bloom that those nutrients support. Hydroelectric regulation flattens the river hydrograph, holding back the freshet and raising winter discharge, and in doing so it redistributes nutrient delivery in time. Across twenty subarctic rivers spanning the Arctic [...]
Deforestation Edge Effects on Soil Moisture Persistence in the Amazon Basin: Observational Evidence for Lateral Hydrological Degradation and Minimum Viable Restoration Scales
Published: 2026-05-22
Subjects: Atmospheric Sciences, Environmental Monitoring, Forest Sciences, Hydrology
Deforestation in the Amazon basin degrades not only the cleared land but also the hydrological function of adjacent intact forest. Here we combine 10 years of SMAP Level 4 root-zone soil moisture (9 km, 2015 to 2024) with Hansen Global Forest Change data (30 m) to quantify how proximity to deforestation edges affects soil moisture persistence in intact forest across the Amazon basin. We classify [...]
First Observational Evidence That Biological Giant CCN Control Urban Rainfall Character: A Natural Experiment from Islamabad's Paper Mulberry Removal
Published: 2026-05-22
Subjects: Atmospheric Sciences, Earth Sciences, Hydrology, Meteorology
Modeling studies predict that biological aerosol, specifically pollen acting as giant cloud condensation nuclei (GCCN), can modify precipitation character by initiating collision-coalescence and warm rain in shallow cloud (Steiner et al., 2015; Wozniak et al., 2018; Paukert et al., 2025). No observational study has tested this prediction. We exploit a natural experiment, the removal of ~29,000 [...]
CryoSentinel: A Multimodal Foundation-Model Segmenter for Glacial Lakes in High Mountain Asia from Sentinel-1 SAR, Sentinel-2 Optical, and Copernicus DEM Imagery
Published: 2026-05-16
Subjects: Artificial Intelligence and Robotics, Environmental Monitoring, Geomorphology, Glaciology, Hydrology
Glacial-lake outburst floods (GLOFs) are the dominant climate-driven hazard in High Mountain Asia, and reliable lake-extent segmentation is the prerequisite for every downstream early-warning workflow. We present CryoSentinel, a multimodal foundation-model semantic segmenter built on the IBM/ESA TerraMind 1.0 Large encoder (1.1 B parameters) with a UperNet decoder, fine-tuned on 5,614 [...]
Drying summers threaten western North American river ecosystems and a keystone migratory fish
Published: 2026-05-14
Subjects: Ecology and Evolutionary Biology, Hydrology, Water Resource Management
Climate change threatens river ecosystems by altering the seasonal streamflow patterns to which aquatic species have adapted, including keystone species like Chinook salmon in western North America. Chinook salmon display diverse life-history adaptations to local hydrologic regimes, contributing to their past resilience but leaving locally adapted populations vulnerable to changing conditions. [...]
Pakistan's Orographic Ladder: Terrain-Constrained Water Potential and the Atmospheric Mechanism Suppressing It
Published: 2026-05-14
Subjects: Atmospheric Sciences, Climate, Hydrology
Pakistan's north-south topographic gradient, 0 m at the Arabian Sea coast rising to 8,611 m at K2 across five distinct ridge systems, represents one of the largest orographic condensation machines on the planet. The terrain's theoretical water yield, set by Arabian Sea moisture flux and ridge geometry alone, far exceeds what Pakistan currently captures. We show that a single atmospheric variable, [...]
swmm-breach: Probabilistic dam-breach hydrograph forecasting integrated with EPA SWMM and PCSWMM
Published: 2026-05-13
Subjects: Hydraulic Engineering, Hydrology
The U.S. EPA Storm Water Management Model (SWMM) and its commercial extension PCSWMM are among the most widely deployed open-source urban-hydrology engines worldwide, but neither provides a native facility for simulating embankment-dam, detention-basin, or lagoon failure. Practitioners working on dam-adjacent SWMM models typically generate a breach hydrograph in HEC-RAS, losing their SWMM network [...]
Causal analyses reveal changing land-atmosphere patterns and soil moisture control under warming
Published: 2026-05-12
Subjects: Geophysics and Seismology, Hydrology
Climate change is projected to modify the global water cycle and land-atmosphere interactions. However, warming-induced changes in multivariate dependence remain insufficiently explored. Here we examine the interdependence among temperature, precipitable water, precipitation, evaporation, soil moisture, and runoff in all five earth system models within the latest IPCC CMIP6 ensembles that [...]
TUD-L3-EWH_UNC-GRACE: A Global Level‑3 GRACE(-FO) EWH Uncertainty Product
Published: 2026-05-08
Subjects: Earth Sciences, Glaciology, Hydrology, Other Earth Sciences
We present TUD-L3-EWH\_UNC-GRACE, a globally gridded Level-3 GRACE(-FO) equivalent water height (EWH) data product providing an extensive characterisation of uncertainty for direct use in Earth system research. Unlike conventional approaches that either require propagation of full normal matrices or rely on empirical assumptions regarding temporal and spatial correlations, the dataset combines [...]
Remotely sensed evapotranspiration for corporate water stewardship: Opportunities and limitations in agricultural landscapes
Published: 2026-05-07
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Natural Resources and Conservation, Sustainability, Water Resource Management
Corporate water stewardship (CWS), in which companies engage in or incentivize actions to advance sustainable water resource management, can positively affect water resources, reduce water-related business risks, and support Environmental, Social, and Governance (ESG) and sustainability reporting efforts. Agricultural landscapes affect diverse industries including finance, technology, fuel [...]
Sustained Decline of Annual Snow Cover Area in the Sikkim Himalaya (1987–2025): Multi-Sensor Remote Sensing on Google Earth Engine, Machine Learning, and Projections to 2100
Published: 2026-05-03
Subjects: Climate, Glaciology, Hydrology, Planetary Glaciology, Planetary Hydrology, Remote Sensing
Snow cover is a critical component of the Himalayan cryosphere, providing freshwater to millions of people across South Asia and regulating regional climate through albedo feedbacks. Sikkim, a small but ecologically significant state in the Eastern Himalaya, has experienced accelerating glacial retreat and mounting hydrological stress in recent decades. This study presents a comprehensive, [...]
Extreme recharge triggers seismicity in a confined karst aquifer in southern Spain
Published: 2026-05-01
Subjects: Earth Sciences, Geophysics and Seismology, Hydrology, Tectonics and Structure
Hydrological forcing during extreme recharge events can perturb crustal stress and trigger seismicity in a critically stressed crust, yet the coupling between aquifer dynamics and the spatio-temporal distribution of earthquake swarms remains poorly constrained. Here we document such a response during an exceptional rainfall episode in early 2026 that affected a confined karst aquifer in southern [...]
Why the Cap-Ferret sand spit is collapsing
Published: 2026-04-27
Subjects: Geomorphology, Hydrology, Oceanography, Sedimentology
The Cap-Ferret sand spit (SW France) exhibits a pattern of coastal instability that combines chronic shoreline retreat (8.7 m·yr⁻¹ at the tip, Robinet et al. 2025), sudden vertical collapses of emplaced structures (WW2 blockhaus 2024, 2026; oyster-farm sector 1936, 1977; Hortense promenade 1999, 2000, 2014, 2019), and progressive deepening of submarine pits (Hortense-Pointe depression volume [...]
Continuous Water Surface Elevation Estimates Using Deep Learning with Legacy Altimetry and Surface Water and Ocean Topography Data
Published: 2026-04-24
Subjects: Earth Sciences, Environmental Sciences, Hydrology, Physical Sciences and Mathematics, Water Resource Management
We present the development of a high-temporal-resolution global dataset of daily river water surface elevation (WSE), spanning January 2008 through May 2025. By utilizing a deep learning framework to integrate legacy satellite altimetry and the Surface Water and Ocean Topography (SWOT) mission data, we produced a continuous record covering 9,184 river reaches, 5,926 rivers, and 1,342 basins. The [...]
Quantifying hydropower flexibility during extreme temperature events
Published: 2026-04-20
Subjects: Computational Engineering, Environmental Engineering, Hydraulic Engineering, Hydrology, Other Civil and Environmental Engineering, Other Mathematics, Power and Energy, Systems Engineering
Extreme weather events can impose substantial stress on the electrical grid. Hydropower offers unique operational flexibility, enhancing grid resilience and reliability. Despite this value of flexibility, systematic assessments of hydropower flexibility -- particularly during extreme events -- remain limited. This study is the first to quantify hydropower operational flexibility using 25 years' [...]