Preprints
Filtering by Subject: Hydrology
Was the Pre-Event SWIR Anomaly at Tsangbu Ri a Genuine Glacier-Collapse Precursor? A Calibrated Multi-Glacier Test of the 2026 Case
Published: 2026-09-19
Subjects: Applied Statistics, Geographic Information Sciences, Geology, Geomorphology, Glaciology, Hydrology, Planetary Geology, Planetary Glaciology, Remote Sensing, Spatial Science, Tectonics and Structure
On 26 August 2026 a compound bedrock-and-glacier failure on the northern flank of the Langtang Lirung–Tsangbu Ri (Kimshung) massif, Nepal–China border, generated a rock–ice avalanche and a catastrophic downstream flood along the Bhotekoshi–Trishuli river system. A pre-event Sentinel-2 shortwave-infrared (SWIR2–NIR–Red) composite (12 August 2026) shows a sharply bounded, strongly saturated [...]
From data availability to evidence sufficiency. PIH MS as an auditable framework for diagnosing hydrogeological knowledge gaps in Mato Grosso do Sul, Brazil
Published: 2026-09-11
Subjects: Earth Sciences, Hydrology, Natural Resources Management and Policy
Groundwater registries can be extensive yet fail to demonstrate the evidence chain required to answer a hydrogeological question. We present PIH MS, an experimental framework that audits a bounded corpus of acquired records and makes knowledge gaps visible without predicting groundwater occurrence. The framework organises 12 evidence layers, nine knowledge dimensions, 39 declared requirement [...]
Deglacial Mass-Movement Floods as a Potential Source of Catastrophic Flood Traditions: A Testable Geomythological Hypothesis
Published: 2026-09-05
Subjects: Earth Sciences, Geology, Geomorphology, Glaciology, Hydrology
Catastrophic flood traditions occur in many geographically separated cultures, but their possible geological substrates need not be uniform. Existing explanations include river floods, earthquake and volcanic tsunamis, glacial-lake outburst floods, postglacial sea-level rise, and cultural transmission. This paper proposes a complementary, explicitly testable hypothesis: during the terminal [...]
The Vulnerability Spiral: Compound Climate Risk Across Five Islands
Published: 2026-09-05
Subjects: Biodiversity, Earth Sciences, Environmental Monitoring, Environmental Sciences, Environmental Studies, Geographic Information Sciences, Geography, Geomorphology, Hydrology, International and Area Studies, Marine Biology, Natural Resource Economics, Nature and Society Relations, Oceanography and Atmospheric Sciences and Meteorology, Other Environmental Sciences, Other Geography, Remote Sensing, Spatial Science, Statistical Methodology, Statistical Models, Sustainability
sea level rise stacked on top of degrading natural coastal defenses. That assumption is rarely tested againstindependent, multi temporal evidence, and rarely broken down by ecosystem type, so I tested it directly,across 5 islands spanning 3 ocean basins (Maldives, Lakshadweep, [...]
Forest–Water–Atmosphere Theory: A Multiscale Framework for Management-Induced Coupling in Forested Landscapes
Published: 2026-09-03
Subjects: Hydrology
Recent advances in ecohydrology, land–atmosphere coupling and Earth System Science increasingly recognize the importance of forests for coupled water, energy and climate dynamics. However, the explicit integration of forest management, multiscale hydrological pathways and atmospheric feedbacks remains limited, despite increasing recognition of forests as active biophysical regulators within [...]
Investigation of Drivers and Sources of Potential Harmful Algal Blooms in Lake Anna, Virginia, 2023–24
Published: 2026-09-02
Subjects: Biogeochemistry, Earth Sciences, Environmental Monitoring, Environmental Sciences, Hydrology, Physical Sciences and Mathematics, Water Resource Management
Algal blooms in freshwater reservoirs are an increasing concern because of the risk to aquatic ecosystem health, recreational use, and water quality. Among the taxa that comprise an algal bloom, cyanobacteria are of particular concern due to the potential to produce toxic compounds which can cause acute and chronic illness in humans if ingested through contaminated water or shellfish. When toxins [...]
A cascade, not a flood: testing the competing accounts of the 26 August 2026 Lhende Khola–Bhote Koshi disaster
Published: 2026-09-02
Subjects: Earth Sciences, Geomorphology, Glaciology, Hydrology, Physical Sciences and Mathematics
On 26 August 2026 a rock–ice mass detached above the Lhende Khola on the China–Nepal border, blocked the channel, and released a flow that travelled about 100 km down the Bhote Koshi and Trishuli, killing hundreds of people and removing about a tenth of Nepal's generating capacity in a single morning. Reporting produced mutually incompatible accounts of the cause, while the agency best placed to [...]
The 26 August 2026 Langtang Lirung ice–rock avalanche and its transboundary cascade: a multi-source observational reconstruction in the Bhote Koshi basin
Published: 2026-09-01
Subjects: Geomorphology, Glaciology, Hydrology
On 26 August 2026, an ice–rock avalanche detached from the northern flank of Langtang Lirung (7,227 m) at about 5,200 m a.s.l., transformed into a debris flow that travelled roughly 22 km in 6–7 minutes, destroyed the Gyirong border port (China) and dammed the river; a flood then propagated a reported ~170 km down the Bhote Koshi–Trishuli–Narayani system into Nepal and India. At least 16 people [...]
The Bhote Koshi–Trishuli flash flood of 26 August 2026, Rasuwa, Nepal: warning latency exceeded flood travel time
Published: 2026-08-29
Subjects: Earth Sciences, Environmental Monitoring, Hydrology
An ice-rock mass detached from the northern flank of the Langtang massif, Nepal, at 08:37:10 Nepal Time on 26 August 2026. It blocked the Lhende Khola and released a cascade that killed more than 500 people along the Bhote Koshi-Trishuli-Narayani corridor. This study measures the warning chain end to end, timing the front at six stations from ten-minute stage series recovered from the river-watch [...]
Automated karst spring catchment approximation for discharge modelling
Published: 2026-08-28
Subjects: Hydrology
Karst spring discharge modelling is complicated by the limited availability of hydrogeologically delineated catchments, particularly in large-sample applications. We present an automated approach to approximate karst spring catchments from discharge, gridded recharge, and topography and evaluate its suitability for discharge modelling at 63 springs across the wider Alpine region. Recharge-area [...]
ALPAKAS: Alpine hydrographs and catchment attributes for karst springs
Published: 2026-08-25
Subjects: Earth Sciences, Hydrology
Approximately 40 % of the European Alps consist of karstifiable rock. Due to their distinct recharge, storage, and discharge properties, karst aquifers are key components of the hydrological cycle and water supply in the Alpine region. However, large-sample datasets enabling comparative and data-driven analyses of karst spring discharge are currently lacking. Here, we present ALPAKAS (ALPine [...]
AquaContam: machine-learning models of drinking-water contamination learn who is monitored as much as where contamination occurs
Published: 2026-08-24
Subjects: Environmental Sciences, Hydrology
Machine learning informs drinking-water monitoring, yet administrative data record the monitoring process as much as the contamination. Using AquaContam (over 4 million samples from 95,223 U.S. water systems and ambient monitoring locations), we find provenance proxies dominate feature attributions, and an apparent lead-model AUROC of 0.962 is largely a target- leakage artifact (corrected skill [...]
Flood Susceptibility Mapping and Engineering Exposure Assessment of Zhob District, Balochistan, Using Sentinel-1 SARValidated AHP and Frequency Ratio Modeling
Published: 2026-08-22
Subjects: Earth Sciences, Geomorphology, Hydrology
Zhob District in northern Balochistan was substantially affected by the 2022 Pakistan monsoon floods, yet, unlike comparable districts mapped in the immediate aftermath of the same event (Larkana, Nowshera, Pishin, Quetta), it has lacked a dedicated, district-specific flood susceptibility assessment. This study addresses that gap using a hybrid Analytic Hierarchy Process (AHP) and Frequency Ratio [...]
Hydrodynamic controls on mineral precipitation in porous media: From pore-scale clogging to continuum permeability upscaling
Published: 2026-08-21
Subjects: Hydrology
Mineral precipitation can sharply reduce permeability in reactive porous media, yet continuum models commonly represent this effect using fixed porosity-permeability relationships that do not account for hydrodynamic controls on precipitation localisation. Here we use pore-scale reactive transport simulations of calcite precipitation in six synthetic two-dimensional porous structures to examine [...]
Flooded Rivers, Drying Wetlands, Vanishing Tributaries: Hydrological Paradox of the East Ganga Plains
Published: 2026-08-17
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 [...]