Changes in river flows, especially extreme high and low flows, could be a particularly important impact of climate change in terms of the hazard to people and the environment. Here, a national-scale grid-based hydrological model is applied, with ensembles of global and regional climate projections from UK Climate Projections 2018, to investigate the potential future changes in both floods and droughts

Many present-day statistical schemes for postprocessing weather forecasts, in particular precipitation forecasts, rely on calibration using prescribed statistical models to relate forecast statistics to distributional parameters. The efficacy of such schemes is often constrained not only by prescribed predictor-predictand relation, but also by arbitrary choices of temporal window and lead time range

Surface depressions are important topographic characteristics for surface runoff initiation, and the spatial distribution of depressions may further affect the timing and quantity of surface runoff reaching channels and outlets. However, many hydrologic models simulate the fill-spill processes for depression-dominated areas in a lumped manner and release outflows from depressions to channels or outlets

About 40% of global crop production takes place on irrigated land, which accounts for approximately 20% of the global farmland. The great majority of freshwater consumption by human societies is associated with irrigation, which contributes to a major modification of the global water cycle by enhancing evapotranspiration and reducing surface and groundwater runoff. In many regions of the world irrigation

Hydraulic fracturing is a process aimed at improving the productivity of oil, gas or geothermal reservoirs. During hydrofracturing, backflow follows injection and represents the second phase of the process, when part of the fracturing fluid returns from fractures to well, and from well to surface. A conceptual model is presented to grasp the essential features of the phenomenon, conceiving the draining

Inverse modeling of large-scale spatially variable parameters fields at fine resolution can be reduced to estimating the projections on dominant principal components of the underlying parameter fields based on principal component analysis of the spatial covariance. For unknown or biased prior structural parameters of spatial covariance models, an iterative procedure consisting of two successive steps

We encounter three-phase flow in porous media within a range of settings, such as enhanced oil recovery, geologic CO2 sequestration, and groundwater remediation. While an abundance of studies has been performed on the behavior of two fluid phases (e.g. oil/water or air/water) in porous media, relatively little information exists for three-phase flow systems (e.g. oil/water/air). This work explores

Numerical solution of Richards’ equation remains challenging to get robust, accurate and cost-effective results, particularly for moving sharp wetting fronts. An adaptive strategy for both space and time is proposed to deal with 2D sharp wetting fronts associated with varying and possibly vanishing diffusivity caused by nonlinearity, heterogeneity and anisotropy. Adaptive time stepping makes nonlinear

The consumption of local blue-green physical water (blue-green PW) is linked to imported virtual water (imported VW) within economic production. The quantitative analysis of interactions between blue-green PW and imported VW is important for integrated management of water resources in inland arid areas. This study used the North Tianshan Mountains (NTM) as a case study to demonstrate the construction

This study aims to analyze model reproducibility on large wood collisions on moveable channel beds. Flume experiments were conducted to observe the responses of moveable bed change with the behavior of large wood, including wood collisions. In the experiments, we employed time intervals of 5 and 9 s in wood supply, which modified the collision patterns. Subsequently, we conducted simulations based

Fundamental understanding of processes controlling geological carbon sequestration (GCS) requires flow and transport modeling in well-characterized aquifer sedimentary deposits. We use three-dimensional, heterogeneous models based on new field studies which incorporate the most important aspects of multiscale architecture in fluvial aquifers. In addition, we use the associated facies-dependent constitutive

Traditional probabilistic methods for the simulation of advection-diffusion equations (ADEs) often overlook the entropic contribution of the discretization, e.g., the number of particles, within associated numerical methods. Many times, the gain in accuracy of a highly discretized numerical model is outweighed by its associated computational costs or the noise within the data. We address the question

Clogging of porous media is controlled by attachment of particles and their subsequent detachment. In this study, we explore particle transport at the pore scale by considering attachment and detachment processes. We use pore structures of three samples which have similar topological properties but different initial porosities. The main focus is on particle detachment, after they are attached to the

Soybean import accounts for 90% of China's total domestic soybean supply. Such import has a substantial impact on how the country's resources are used as well as on its environment. In this study, we performed a national-scale assessment of the impact of soybean import on domestic cropland conversion, crop production, water use and nitrogen (N) fertilizer application. Results show that soybean production

Few ensemble streamflow forecasting systems are designed to operate for ephemeral rivers. In this study, we revise our error model for generating Forecast Guided Stochastic Scenarios (FoGSS) to produce statistically reliable long-range (12-month) forecasts for ephemeral rivers. FoGSS features an error model with four stages: data transformation, bias-correction, an autoregressive error model and the

In this article, a δ+-LES-SPH model is presented to study the generation and propagation of impulse waves. In this model, a density diffusion term is added to the continuity equation to eliminate the numerical high-frequency oscillation of the pressure field. A particle shifting technique is introduced and modified in the motion equation to improve the accuracy and robustness of the smoothed particle

Anisotropy is a common feature for most of fibrous and porous media. This article reports a new method for measuring the 2D anisotropic permeability of a porous rock utilizing the measurements obtained from the steady-state flow between two concentric cylinders. The mathematical analysis of the experimental data is based on the general solution of the pressure equation derived for the steady-state

The plasticity of root water uptake determines the maintenance of transpiration during periods of water limitation and drought. However, the mechanistic basis of plant water uptake, as well as the implications of water uptake strategies at the individual and ecosystem scale remain elusive. We model three-dimensional root water uptake under variably saturated conditions for a one-hectare temperate forest

Satellite altimetry is increasingly considered as a valuable source of information in many hydrological and hydraulic applications. However, the accuracy of different sensors adopted for monitoring the water level from satellite and the limited temporal resolution that characterizes each sensor (i.e. revisit time most of time varying from 10 to 35 days; 369 days in case of CryoSat mission) still hamper

How floods respond to changing climate is of great concern in research community and society, but there is no consistent conclusion about whether floods are as sensitive to changes in temperature as precipitation extremes. In this study, the responses and connections of local floods to temperature and precipitation extremes over three hydroclimatically different regions across the United States were

Traditional interpolation techniques for particle tracking include binning and convolutional formulas that use pre-determined (i.e., closed-form, parameteric) kernels. In many instances, the particles are introduced as point sources in time and space, so the cloud of particles (either in space or time) is a discrete representation of the Green’s function of an underlying PDE. As such, each particle

We investigate the impact of sub-grid scale horizontal lamination on the migration of the CO2 plume during geologic sequestration. A new physics-based model that includes the effects of capillary and viscous forces is used to obtain effective flow-rate dependent capillary pressure and relative permeability functions. For this purpose a macroscopic capillary number is derived that accurately describes

Permeability characterises flow in porous rocks/media for upscaling, while steady-state flow fields allow analysis of reactive transport, fines migration, and tight unconventional rocks. Fast calculation of permeability and flow fields obtained from Pore Network Models (PNM) and Laplace Semi-Analytical Solvers (SAS) deviate from computationally demanding simulation of Navier Stokes Equations (NSE)

Multi-decadal prediction of estuarine sedimentation with high-fidelity hydromorphodynamic models presents high computation costs, especially when accounting for stochasticity and uncertainty. A StochAstic model for Multi-decadaL Estuarine Sedimentation (SeAMLESS) is formulated here to support a specific decision-need related to resilience planning and coastal management: estimating future sedimentation

Advances in instrumentation have made it possible to obtain high-resolution images of heterogeneous porous media. Such advances and the rapid increase in computational power mean that direct numerical simulation of multiphase flow in two- and three-dimensional (3D) images of porous media is feasible and, therefore, models of pore space that represent simplification and approximation of the actual morphology

Foam injection is an effective method for modifying gas mobility in subsurface flow applications making it ideal for environmental remediation applications. Remediation of contaminated soils/aquifers of nonaqueous phase liquids using foamed surfactant solutions is a viable option but a predictive foam model is needed that is flexible to the addition of more accurate physical descriptions. Such a model

The inherent complexity of the fluid flow in subsurface systems brings potential inevitable uncertainty in their characterization. Computationally intensive high-dimensional inversion problems often emerge in solving the fluid flow problems of various scenarios, which required to be probed. To improve the efficiency of solving such problems, surrogate strategies are widely used to quantify the uncertainty

Intermittent fluid flow has recently been identified as an important transport mode for processes involving subsurface multiphase fluids such as CO2 storage and natural gas production. However, due to experimental limitations, it has not been possible to identify why intermittency occurs at subsurface conditions and what the implications are for upscaled flow properties such as relative permeability

Groundwater plays a major role in human adaptation and ecological sustainability against climate variability by providing global water and food security. In the Indus-Ganges-Brahmaputra-Meghna aquifers (IGBM), groundwater abstraction has been reported to be one of the primary contributors to groundwater storage variability. However, there is still a lack of understanding on the relative influence of

Subsurface flow model calibration against dynamic response data is often constrained by a prior conceptual model of geologic scenario that specifies the expected spatial variability and geologic patterns in the solution. However, several sources of uncertainty exist in developing a conceptual geological model, including data limitation, process-based modeling assumptions, and subjective interpretations

Beef cattle production systems hide an enormous variability of productive and management aspects that impact the water footprint value. To have a greater precision in decision making based on water footprint we should consider animal-individuality and propose managements solutions. The aims of this study were to calculate the water footprint for a tropical cattle production system and to evaluated

Laboratory scale experiments and numerical modelling were employed in this study to investigate saltwater intrusion in fractured aquifers. Saline intrusion was initiated in one homogeneous and six fractured experimental aquifers containing individual discontinuities of varying length and orientation. Automated image processing enabled high precision quantification of three intrusion variables, the

In this work, different Generalized Double Porosity Models for anomalous fluid flow in fractured porous media are presented, and transient production decline applications discussed. The effects of subdiffusive and superdiffusive flows in fracture networks coupled to subdiffusive transport inside the matrix are explored, and some insights into how to identify these types of flow in geological formations

Besides other environmental tracers, the use of the 3H-3He method enables the estimation of modern groundwater ages. Widely used in fresh groundwater studies, the combination of tritium (3H) and its stable daughter product tritiogenic helium-3 (3Hetrit), however, has so far only been applied in a few studies to date groundwater in coastal aquifers. The coastal aquifer presented in this study is located

Detection and attribution of trends in individual at-site series of hydrological extremes is routinely undertaken using simple linear regression-based models. However, the available records are often too short to allow a consistent assessment of trends across different stations in a region. The theoretical developments presented in this paper propose a new method for estimating a regional regression

Travel time distributions (TTDs) provide an effective way to describe the transport and mixing processes of water parcels in a subsurface hydrological system. A major challenge in characterizing catchment TTD is quantifying the travel times in deep groundwater and its contribution to the streamflow TTD. Here, we develop and test a novel modeling framework for an integrated assessment of catchment scale

In this study, we investigate the impact of topological disorder on liquid distribution and transport phenomena in three-dimensional unsaturated granular media using the Shan-Chen lattice Boltzmann method. Distinct samples of disordered media are generated, characterized by the disorder index Iv. Under different Iv, varied liquid cluster distributions are demonstrated in a gravity-driven vapour-liquid

Riffle-pool sequences are fundamental, ubiquitous morphological features of alluvial rivers that are thoroughly studied in general and commonly incorporated into river restoration projects. Most previous investigations on the effect of riffle-pool sequences on hyporheic exchanges focused on solely bed undulation, because that is widely thought to be the defining feature of riffle-pool sequences. However

Using generalizations of the Cahn-Hilliard equation for modeling two-phase flow in porous media at the pore scale has become popular due to its ability to capture interfacial effects by adding minimal complications. Here we use upscaled field equations and exploit the second law of thermodynamics in the spirit of rational thermodynamics to develop a framework that, for two phases at the macroscale

Freezing of unsaturated soil is an important process that influences runoff and infiltration in cold-climate regions. We used a simple numerical model to simulate water and heat transport with phase change in unsaturated soil via three different approaches: empirical, semi-empirical and physically based. We compared the performance and parameterization of each approach through testing on three experimental

Due to the enormous advances in computational power, machine-learning algorithms have recently experienced significant breakthroughs in handling and processing complex and big data. Water resources problems have always been among the issues that researchers have attempted to leverage such advances for various purposes, such as hydrological modeling, fluid flow and transport in porous media, and characterization

Virtual water flow can alleviate the pressure of regional water resources. Differences in water resources endowment and industrial structure among regions cause regional differences in water use in China. Water use in agriculture, especially irrigation, heavily rely on both surface water and groundwater. Virtual water flow may have different influence on the utilization and exploitation of regional

Many important groundwater transport applications require solving the Darcy flow in heterogeneous porous media. Flow simulations, especially in large, highly heterogeneous aquifers, require extensive computational resources, a multiresolution (multiscale) approach to resolve the different heterogeneity scales and an accurate calculation of the velocity field. Common methods, such as finite volumes

This study concerns numerical methods for efficiently solving the Richards equation where different weak formulations and computational techniques are analyzed. The spatial discretizations are based on standard or mixed finite element methods. Different implicit and semi-implicit temporal discretization techniques of second-order accuracy are studied. To obtain a linear system for the semi-implicit

Aquatic vegetation dramatically shifts the main flow, secondary flow and turbulent structures in a meandering channel. In this study, hydrodynamics in a bending channel with a vegetation patch (VP) has been numerically studied under the variation of curvature ratios (CRs=0.5, 1.0, 1.5, 2.0) and the vegetation density i.e. Solid Volume Fractions (SVF=1.13%, 4.86%). Both effects on vegetation shear flow

This work provides a comprehensive analysis of soil water dynamics in Australia for the climate projections of the Coupled Model Intercomparison Project 6 (CMIP6). We modelled the historical soil water dynamics from 1981 to 2018 at various depths within and below the root zone using the BRTSim computational solver to generate the "current conditions". We then investigated how the CMIP6 scenario can

Nanoparticle (NP) transport is increasingly relevant to subsurface engineering applications such as aquifer characterization and enhanced oil recovery. An efficient field-scale simulation framework is critical for predicting NP performance and designing subsurface applications. In this work, for the first time, a streamline-based model is presented to simulate NP transport in field-scale subsurface

Steady shallow flows past an open channel lateral cavity can induce the excitation of an eigenmode of a gravity standing wave inside the cavity, called seiche, which may be coupled with the shedding of vortices at the opening of the cavity. The presence of the seiche is of fundamental interest as it enhances the mass exchange between the main channel and the cavity. Measurements of the time evolution

Accurate prediction of flood inundation processes in urban areas is challenging, due to the complexity of street layouts and the variety of infrastructures. In this study, based on a laboratory model of urban flooding with a sewer system underneath, a series of laboratory experiments were conducted to investigate the influences of different street layouts and infrastructures on flood inundation processes

We present two statistical models for downscaling flood hazard indicators derived from upscaled shallow water simulations. These downscaling models are based on the decomposition of hazard indicators into linear combinations of spatial patterns obtained from a Principal Component Analysis (PCA). Artificial Neural Networks (ANNs) are used to model the relationship between low resolution (LR) and high

The coefficient of the Brutsaert-Nieber equation cannot provide information on streamflow dynamics independently because its value depends on the exponent. One way to address this challenge is to compute the coefficient after fixing the exponent, which may involve fitting errors. A recent study has therefore adopted a method to decorrelate the coefficient from the exponent. Here, I argue that the decorrelation

Fine-scale discrete fracture simulations provide a natural means to quantify the matrix-fracture fluxes and to specify reference solutions for upscaling approaches such as dual porosity/dual permeability models. Since typically the fine-scale simulations are computationally demanding, and the fractured reservoirs are highly heterogeneous, it is desirable to parametrize the fracture geometry and to

Climate change is expected to significantly alter river hydrological regimes throughout the world, affecting water resources and the frequency of floods and droughts. The objectives of this study were to determine the impacts of climate change and sea level rise on streamflow and floodplain inundation in the subtropical Logan-Albert catchment, Australia. An ensemble of 11 high-resolution climate models

Virtual water flows are used to determine the indirect water requirements of a region or product, making them an indispensable tool for water sustainability analysis and assessment. Commodity flows are a key data needed to compute virtual water but are typically available every 5 years in the United States (US). The lack of continuous, annual commodity flow data severely limits our ability to study

We study the spatial structure of soil moisture fields within savanna ecosystems, whose persistence is vital because it is the driver of the entire ecological structure and function. These include changes in the physical and biogeochemical conditions of the landscape, affecting vegetation state, soil composition, water fluxes, and solar radiation. We focus on computations of the probabilistic structure

Data assimilation techniques are widely used in hydrology and water resources management to improve model forecast uncertainty by assimilating observations. The big challenge in practical applications is how to describe model uncertainties correctly to avoid the occurrence of spurious covariance during data assimilation. In this study, the ensemble square root filter (EnSRF) is used to estimate parameters