Small-island populations disproportionately rely on fresh groundwater resources, which are increasingly threatened by salinization from changing ocean and climate conditions. This study investigates island groundwater dynamics and salinization over multiple timescales in response to marine, atmospheric, and morphologic drivers. To address this, new geophysical and hydrological datasets were collected

The emergence of large language models (LLMs), such as ChatGPT, has garnered significant attention, particularly in academic and scientific circles. Researchers, scientists, and instructors hold varying perspectives on the advantages and disadvantages of using ChatGPT for research and teaching purposes. This commentary offers a brief explanation of the fundamental principles behind ChatGPT and how

We focus on nonlinear flow regime scenarios observed at the global scale of a porous medium and explore the impact of such nonlinearities on key features of dispersive scalar transport observed across three-dimensional porous systems characterized by various degrees of pore space complexity. Flow and transport processes are analyzed at pore-scale and larger scales in well-documented digital Beadpack

Managing fragile island freshwater resources requires identifying pumping strategies that trade off the financial cost of groundwater supply against controlling the seawater intrusion (SWI) associated with aquifer pumping. In this work, these tradeoffs are investigated through a sensitivity analysis conducted in the context of an optimization formulation of the groundwater management problem, which

Water plays a central role in several socioeconomic and environmental nexuses. Faced with various anthropogenic pressures that act as water scarcity drivers and knowing that the unavailability of water can be a limiting factor for economic development, there is an urgent need for the design and evaluation of economic instruments that help in the management of water resources. This article presents

In recent years, the use of deep learning methods has rapidly increased in many research fields. Similarly, they have become a powerful tool within the climate scientific community. Deep learning methods have been successfully applied for different tasks, such as the identification of atmospheric patterns, weather extreme classification, or weather forecasting. However, due to the inherent complexity

Inverse modeling of hydraulic tomography (HT) is computationally expensive for estimating high-dimensional hydrogeologic parameter fields. In this work, we develop a novel method called HT-INV-NN, which combines dimensionality reduction techniques with a predictive deep learning (DL) model to estimate high-dimensional Gaussian and non-Gaussian channel fields. The HT-INV-NN model consists of a predictor

Dissolution trapping is one of the crucial trapping mechanisms for geological carbon storage in deep saline aquifers. The injected supercritical CO2 (scCO2) flow and dissolution processes are coupled and interact with each other. Therefore, we performed direct numerical simulations in three-dimensional micro-CT images of sandstones using the Volume of Fluid and Continuous Species Transfer (VOF-CST)

Understanding the macro-scale flow characteristics in the fractured vadose zone is of great importance for subsurface hydrological and environmental applications. Here we develop an idealized fracture network model composed of a series of linked intersections, aiming to reveal the roles of local fluid flow, storage and splitting behaviors at intersections in controlling macroscopic unsaturated flow

Sediment transport load monitoring is important in civil and environmental engineering fields. Monitoring the total load is difficult, especially because of the cost of the bed load transport measurement. This study proposes estimation models for the suspended-to-total load fraction using dimensionless hydro-morphological variables. Two prominent variable combinations were identified using the recursive

Understanding the origins and hotspots of suspended sediments is crucial for safeguarding the biotic communities and for management of water quality in river-reservoir systems. This study is an attempt to develop a new analytical framework to deconvolve the suspended sediment sources contribution using a novel index (i.e. erosion susceptibility index, ESI). The ESI is computed using sediment fingerprinting

The land surface hydrology of the North American Great Lakes region regulates ecosystem water availability, lake levels, vegetation dynamics, and agricultural practices. In this study, we analyze the Great Lakes terrestrial water budget using the NOAH-MP land surface model to characterize the catchment hydrological regimes and identify the dominant quantities contributing to the variability in the

Since the 2008 Wenchuan (Ms. 8.0) Earthquake, the foreland rivers of the Longmen Mountains have suffered from significant bed degradation, among which the Shi-ting River has experienced the largest local degradation of more than 20 m in 7 years. Potential reasons of the dramatic degradation include: (1) sediment disconnectivity due to in-channel weirs; (2) the mobilization effect on gravel of an increased

The Yarlung Zangbo River (YZR) is the largest river in the northern Himalayas, providing crucial water resources for downstream. A full understanding of the streamflow dynamics and regional water budget is critical to secure water security of the Himalayan water tower. Here we establish a comprehensive hydrological model to simulate the precipitation-runoff-evapotranspiration-groundwater-streamflow

Storm surges associated with tropical cyclones endanger atolls through groundwater flooding, wherein groundwater is discharged from the land surface at elevated sea levels. Atolls are characterised by a ‘dual-aquifer’ configuration, where recent Holocene sediments unconformably overlie highly permeable Pleistocene limestone creating an interface called a ‘Thurber discontinuity.’ This study aimed to

Land cover controls the land-atmosphere exchange of water and energy through the partitioning of solar energy into latent and sensible heat. Observations over all land cover types at the regional scale are required to study these turbulent flux dynamics over a landscape. Here, we aim to study how the control of daily and midday latent and sensible heat fluxes over different land cover types is distributed

Sustainable development and intergenerational responsibility entail the prudent use of natural resources. Water availability can constrain agriculture, a key sector in terms of resources consumed and goods and services provided. The sustainability of its intensification and expansion has been studied, often with a particular focus on water. Agricultural strategies have been based on local water availability

Accurate prediction of physical alterations in carbonate reservoirs under dissolution is critical for development of subsurface energy technologies. The impact of mineral dissolution on flow characteristics depends on the connectivity and tortuosity of the pore network. Persistent homology is a tool from algebraic topology that describes the size and connectivity of topological features. When applied

In the context of climate change, the stakes surrounding water availability are rapidly intensifying. Decomposing and quantifying the effects of climate on discharge allows us to understand their impact on water resources better. We propose a methodology to separate the effect of change in the annual mean of climate variables from the effect of the intra-annual distribution of precipitation. It combines

Groundwater input in natural systems can vary over a wide range of time scales due to different natural phenomena and anthropogenic activities. These variations give rise to time-dependent velocity fields, which in turn may influence the dynamics of a migrating chemical plume relative to migration in a constant-velocity domain. Anomalous transport, which is ubiquitous in many groundwater systems and

Large-scale cross-site scientific synthesis on low-flow storage-discharge relation can promote developing transferable hypotheses on the interactions amongst critical zone attributes, and on how such interactions affect catchments' water vulnerabilities. This study leverages cross-site empirical and theoretical analyses and develops a similarity index, based on the interactions amongst critical zone

Sediment transport is a key process that affects the morphology and ecological habitat diversity of rivers. As part of a gravel augmentation program to mitigate sediment deficit below a dam, gravel mobility in the Ain River in Eastern France was investigated by tracking of a large amount (n = 1063) of PIT-tagged gravels in the field, conducting a probabilistic approach based on published tracer studies

The drawdown time is important for the design and assessment of infiltration basins. This paper investigates its dependence on soil heterogeneity, and simple analytical solutions for the mean and the variance are given. The solutions are tested through Monte Carlo simulations in various realistic scenarios, using a modified Green Ampt model for layered soils and a model based on the integration of

In this study, dispersion and mixing were studied in a steady two-phase flow generated using a co-injection method. The impact of oil viscosity was investigated over a large range of fluid viscosity ratios. The results indicate that highly heterogeneous flow fields are generated by a wide distribution of oil clusters with varied volumes. Variation in the velocity distribution enhanced the deformation

Ponding at the soil surface exerts profound impacts on infiltration. However, the effects of ponding depth on infiltration, especially the development of a saturated zone below the soil surface, have yet to be considered in present infiltration models. A new general Green-Ampt model solution (GAMS) was derived for a one-dimensional vertical infiltration problem under a uniform initial moisture distribution

Non-water-limited canopy resistance (rcs, also known as the bulk stomatal resistance or surface resistance) is a critical variable in estimating potential evapotranspiration (PET), which is widely used in ecohydrology related fields. However, quantifying rcs is a challenging work. Here we develop an approach for estimating rcs over the globe. Comparing results over the globe and across 10 ET data sets

Accurate runoff forecasting plays a vital role in issuing timely flood warnings. Whereas, previous research has primarily focused on historical runoff and precipitation variability while disregarding other factors' influence. Additionally, the prediction process of most machine learning models is opaque, resulting in low interpretability of model predictions. Hence, this study develops an ensemble

For large, regulated rivers, operators can impact abiotic conditions for the benefit of the ecosystem, primarily by controlling the volume of discharge from upstream reservoirs. Understanding the decision space around discharge is necessary for evaluating tradeoffs between environmental and other objectives. As a result of climate change, warming water temperatures are increasingly becoming a concern

Perfluoroalkyl acids (PFAAs), a group of synthetic compounds associated with adverse human health impacts, are commonly found in effluent discharged from wastewater treatment facilities. When that effluent is used for irrigation, the fate of PFAAs depends strongly on soil PFAA retention properties and effluent PFAA loading history. The relative importance of PFAA retention factors under natural field-scale

Inflow anomalies at varying temporal scales, seasonally varying storage mandates, and multipurpose allocation requirements contribute to reservoir operational decisions. The difficulty of capturing these constraints across many basins in a generalized framework has limited the accuracy of streamflow estimates in land-surface models for locations downstream of reservoirs. We develop a Piecewise Linear

Clogging of streambeds due to clay deposition influences the stream-subsurface exchange flux and thus directly modulates hyporheic ecological and biogeochemical processes. Clogging of sandy streambeds has previously been studied under losing and gaining flows and during streambed movement, but not when these two flow conditions coincided. We conducted flume experiments to quantify the combined effect

Non-perennial headwaters experience extremes in flow conditions that likely influence carbon fate. As surface waters contract through dry periods, reconnect during storms, and re-expand or dry again, there is a great deal of variability in carbon emissions and export. We measured discharge, dissolved oxygen, carbon dioxide (CO2), and dissolved organic carbon (DOC) continuously in a persistent pool

River deltas typically have high population density and support a wide range of intensive and prosperous socioeconomic activities. The hydrological processes in these regions are complex, primarily due to the interactions among the river, aquifer, and sea. However, a systematic and quantitative elaboration of the river-aquifer-sea interactions is still lacking. Here we developed an integrated hydrological

The western U.S. is experiencing increasing rain to snow ratios due to climate change, and scientists are uncertain how changing recharge patterns will affect future groundwater-surface water connection. We examined how watershed topography and streambed hydraulic conductivity impact groundwater age and stream discharge at eight sites along a headwater stream within the Manitou Experimental Forest

We study the upscaling and prediction of ensemble dispersion in two-dimensional heterogeneous porous media with focus on transverse dispersion. To this end, we study the stochastic dynamics of the motion of advective particles that move along the streamlines of the heterogeneous flow field. While longitudinal dispersion may evolve super-linearly with time, transverse dispersion is characterized by

Since its passage in 1974, the U.S. Safe Drinking Water Act (SDWA) has become a pillar of water resources engineering, utility management, and public health policy. Complementing other environmental legislation from the same period, SDWA set standards for drinking water suppliers, service, and quality and has made an unmistakable positive impact on U.S. communities for the past 50 years. While drinking

Agricultural headwater streams and ditches commonly host dense stands of aquatic vegetation that grow and decay over seasons and exert physical and biological controls on the transport of nutrients from cropland to larger rivers. This study examined changes in the transport of phosphorus (P) in an agricultural drainage ditch in the Maumee River Basin (Ohio, USA) by conducting constant rate injections

Two-phase flow involving non-Newtonian fluids in fractured media is of vital importance in many natural processes and subsurface engineering applications, such as rock grouting, groundwater remediation, and enhanced oil recovery. Yet, how the displacement dynamics is impacted by the non-Newtonian rheology remains an open question. Here, we conduct primary drainage experiments in which a shear-thinning

The clarification of freezing in a soil-water system is critical for assessing the formation of a freezing zone and liquid water flow. The supercooling phenomenon of soil pore solutions has been found during the freezing process, but the mechanism remains poorly understood. In this study, we propose a free energy function of soil-water systems based on the Classical Nucleation Theory. The analytical

The accumulation of large woody debris (LWD) at bridge piers is a serious hazard to the structural integrity of bridges across watercourses worldwide. The exacerbated scour that can directly result from LWD accumulations can lead to major structural damage or even catastrophic collapse. Recent research has led to empirical equations to estimate the scour depth for given LWD accumulation size; however

The spatial configuration of fractures often regulates flow and transport in the subsurface. However, the characterization of fracture networks is a challenging task, especially in deep reservoirs, because here only a limited number of boreholes is available to perform downhole logs and cross-well hydraulic and tracer tests. In this study, we develop a joint inversion procedure to infer fracture number

Highly accurate soil moisture information is necessary to understand land surface processes. However, observational techniques do not produce adequately accurate spatial-temporal continuous regional soil moisture data. The data assimilation method can be used to improve the soil moisture estimations by merging multi-source observed data, but its performance is affected by error covariance and the quality

The change in heat storage (Gc) is an essential component of a lake's energy balance, and its importance for lake evaporation (Ew) has been widely recognized. However, the effect of Gc on Ew exhibits diversity across time dimensions. The controls on Gc and the effects of Gc on Ew estimates at different time scales remain largely unexplored. To address these gaps, we identified the primary controls

The wetting front dynamics during water imbibition in dry porous media affect the ultimate water distribution pattern. In this study, we investigate the impact of pressure pulses that emit waves in the water phase on the water distribution and imbibition patterns in porous media. We present experimental results of water spatial distribution in sand columns following infiltration under abrupt pressured-water

We present the satellite vegetation index time series model for detecting historical floods in ungauged hyperarid regions (SatVITS-Flood). SatVITS-Flood is based on observations that floods are the primary cause of local vegetation expansion in hyperarid regions. To detect such expansion, we used two time-series metrics: (a) trend change detection from the Breaks For Additive Season and Trend and (b)

As drought and wildfire frequency increase across the western United States, our ability to predict how water resources will respond to these disturbances depends on our understanding of the feedbacks that maintain watershed function and streamflow. Previous studies of non-perennial headwater streams have ranked drivers of low-flow conditions; however, there is a limited understanding of the interactions

No abstract is available for this article.

Despite the considerable social and economic benefits of hydropower dams, they can cause total dissolved gas (TDG) supersaturation downstream of hydropower dams, which can harm fish through gas bubble trauma (GBT) and cause issues with aquatic ecology. This paper systematically reviewed the generation and release mechanism of TDG supersaturation, including three stages of TDG generation and release

Reducing flood risk through disaster planning and risk management requires accurate estimates of exposure, damage, casualties, and environmental impacts. Models can provide such information; however, computational or data constraints often lead to the construction of such models by aggregating high-resolution flood hazard grids to a coarser resolution, the effect of which is poorly understood. Through

Ensemble climatological forecasts play a critical part in benchmarking the predictive performance of hydroclimatic forecasts. Accounting for the skewness and censoring characteristics of hydroclimatic variables, ensemble climatological forecasts can be generated by the log, Box-Cox and log-sinh transformations, by the combinations of the Bernoulli distribution with the Gaussian, Gamma, log-normal,

Recession analysis is a powerful tool for determining the hydraulic characteristics of a riparian aquifer. The basis of the method relies on two analytical solutions of the nonlinear Boussinesq equation: one applies to a uniform water table profile in a semi-infinite aquifer while the other pertains to a hypothetical initial profile in a finite aquifer. Both solutions assume that the water depth in

The ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) is a scientific mission that collects high spatio-temporal resolution (∼70 m, 1–5 days average revisit time) thermal images since its launch on 29 June 2018. As a predecessor of future missions, one of the main objectives of ECOSTRESS is to retrieve and understand the spatio-temporal variations in terrestrial evapotranspiration

Snow interacts with its environment in many ways and thus has a highly heterogeneous spatial and temporal variability. Therefore, modeling snow variability is difficult, especially in forested environments. To increase the understanding of the spatio-temporal variability of snow and to validate snow models, reliable observation data at similar spatial and temporal scales is needed. For these purposes

Regionalization approaches—where utilities in close geographic proximity cooperate to manage drought risks and co-invest in new infrastructure—are increasingly necessary strategies for leveraging economies of scale to meet growing demands and navigate financial risks. However, regionalization also brings new challenges to water supply planning. Successful regionalization policies must equitably balance

We studied thermal dispersion in a fracture walled by a porous and permeable rock matrix, where the fluid flow and heat transport are coupled across the interface between these media. The reduced order model of the advective-dispersive heat transport in the fracture-matrix system is resulted from the Reynolds decomposition. The model allows the calculations of the upscaled dispersion and advection

Hypoxic blackwater events occur worldwide, affecting inland and coastal waters. These events have been exacerbated by man-made floodplain drainage, leading to large-scale fish kills and ecological degradation. This paper presents a new method to identify estuarine catchment areas that are most likely to generate hypoxic conditions. The method uses established risk factors, including vegetation type

Srivastava and Yeh (1991, https://doi.org/10.1029/90WR02772) derived an exact solution to the linearized Richards equation (LRE) for two-layer medium infiltration using the Laplace transform (LT) method with a particular initial condition assumed, making the most pioneering contribution to the derivation of exact solutions to the layered-medium LRE (i.e., ES-LMLREs). However, the LT method is unsuitable

Stream confluences are ubiquitous interfaces in freshwater networks and serve as junctions of previously independent landscapes. However, few studies have investigated how confluences influence the transport, mixing, and fate of organic matter (OM) and inorganic nutrients at the scale of river networks. To understand how network biogeochemical fluxes may be altered by confluences, we conducted two

Groundwater systems are commonly defined as renewable or non-renewable based on natural fluxes of recharge or on estimates of aquifer storage and groundwater residence time. However, we show here that the principle of capture (i.e., how recharge and discharge change due to pumping) challenges simple definitions so that a groundwater system cannot be renewable or non-renewable in and of itself, but

Reflectivity bias of ground-based weather radar (GR) is a common error source that can lead to biases in quantitative precipitation estimation (QPE). In this study, the Dual-frequency Precipitation Radar onboard the Global Precipitation Measurement Mission Core Observatory (GPM-DPR) is used to correct GR reflectivity bias. The reflectivity bias correction comprehensively considers variations in GR-DPR