Advances in Water Resources最新文献

{"title":"Assessment of hybrid RANS/LES models for the prediction of the flow and scour around a wall-mounted cylinder","authors":"Alban Gilletta , Cyrille Bonamy , Marie Robert , Julien Chauchat","doi":"10.1016/j.advwatres.2025.104934","DOIUrl":"10.1016/j.advwatres.2025.104934","url":null,"abstract":"<div><div>In many environmental flow situations, a solid body emerges from a sediment bed. This may occur in natural systems, for example when a tree-root emerges from the bed, or around a man-made structure such as a bridge pier or a wind turbine foundation. When this situation occurs, various flow-structure interactions such as the horseshoe vortex or vortex shedding lead to the scour process, namely the erosion pattern around the solid obstacle. In this context, accurate numerical prediction of the flow-structure interactions is of primary importance. In this contribution, three-dimensional hydrodynamic simulations are performed using the single-phase incompressible flow solver pimpleFOAM (OpenFOAMv2206plus). Two hybrid RANS-LES turbulence models available in OpenFOAM are tested: the non-zonal <span><math><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></math></span>SST-SAS model and the zonal <span><math><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></math></span>SST-IDDES model. As a first benchmark, a plane channel flow configuration at large bulk Reynolds number (<span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>b</mi></mrow></msub><mo>=</mo></mrow></math></span>1.9 <span><math><mo>×</mo></math></span> 10<sup>4</sup>) is investigated to evaluate the mesh requirements and to determine a set of acceptable numerical parameters. These simulations show that while the <span><math><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></math></span>SST-IDDES model allows to simulate some features of the fluctuating motions with fewer grid requirements than LES, the <span><math><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></math></span>SST-SAS model behaves as a RANS model. Concerning the wall-mounted cylinder flow at high Reynolds number (<span><math><mrow><mi>R</mi><msub><mrow><mi>e</mi></mrow><mrow><mi>b</mi></mrow></msub><mo>=</mo></mrow></math></span>1.8 <span><math><mo>×</mo></math></span> 10<sup>5</sup>), the conclusions are quite different, the <span><math><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></math></span>SST-SAS model switches to LES in the region of interest namely the horseshoe-vortex region and the wake thanks to its non-zonal property. The <span><math><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></math></span>SST-SAS model provides better predictions than the <span><math><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></math></span>SST-IDDES model in terms of amplitude of the bimodal oscillation and vortex merging processes in the horseshoe vortex at lower CPU cost than LES. After this benchmarking and assessment of the hybrid RANS-LES model, a new <span><math><mrow><mi>k</mi><mo>−</mo><mi>ω</mi></mrow></math></span>2006-SAS turbulence model has been developed for the two-phase flow solver <em>sedFOAM</em>. The model is then applied to a scour configuration around a wall-mounted cylinder and successfully represents the upstream scour depth. The simulations improve the resolution of the complex horseshoe-vortex dynamics which is directly in","PeriodicalId":7614,"journal":{"name":"Advances in Water Resources","volume":"199 ","pages":"Article 104934"},"PeriodicalIF":4.0,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transfer learning for geological carbon storage forecasting using neural operator","authors":"Andres Nunez ,&nbsp;Siddharth Misra ,&nbsp;Yusuf Falola","doi":"10.1016/j.advwatres.2025.104948","DOIUrl":"10.1016/j.advwatres.2025.104948","url":null,"abstract":"<div><div>Geological carbon storage (GCS) is critical for sequestering CO₂ deep underground. GCS projects may face environmental challenges, such as leakage risks, adverse pressure buildup, and groundwater contamination. Numerical simulators play a vital role in accurate forecasting but can be computationally expensive. In this work, we leveraged an updated Fourier Neural Operator (FNO) which includes data sparsity management, to learn to rapidly forecast pressure and CO₂ phase saturation distributions in a geological carbon storage (GCS) reservoir. Compared to commercial reservoir simulators, FNO-based forecasting offers accurate prediction while reducing the computational time by a factor of 40, enabling high volume of forecasting in less time. Additionally, we applied transfer learning (TL) to further reduce the data and computational requirements of the FNO-based forecasting across a wide array of scenarios. Specifically, we demonstrated the usefulness of TL in accurately predicting the pressure and CO₂ saturation distributions for uncertain and variable geological and operational conditions. The results of this study indicate that the improved FNO workflow reduces the computational time by approximately 97 %, and the relative mean error for predicting both CO₂ saturation and pressure distributions is &lt;1 %. Generally, the use of TL effectively transfers knowledge from a pre-existing model to other related tasks. TL significantly reduces the required training data by 78 % while maintaining a relative mean error below 5 %. Although, the results in this work can be further improved, this study demonstrates the potential of integrating FNO and TL to reduce computational time and data requirements for CO₂ forecasts during GCS projects, providing a more efficient and faster approach.</div></div>","PeriodicalId":7614,"journal":{"name":"Advances in Water Resources","volume":"199 ","pages":"Article 104948"},"PeriodicalIF":4.0,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling surface-subsurface flow interactions of a salmon redd","authors":"Brandon Hilliard ,&nbsp;William J. Reeder ,&nbsp;Ralph Budwig ,&nbsp;Vibhav Durgesh ,&nbsp;Bishal Bhattarai ,&nbsp;Benjamin T. Martin ,&nbsp;Tao Xing ,&nbsp;Daniele Tonina","doi":"10.1016/j.advwatres.2025.104947","DOIUrl":"10.1016/j.advwatres.2025.104947","url":null,"abstract":"<div><div>Female salmonids bury their eggs in streambed gravel by digging a pit where they lay their eggs, which they then cover with gravel from a second pit, forming a rough-surfaced dune-like structure called a redd. The interaction between a redd and the stream flow induces surface water to flow into the sediment, through egg pockets, and reemerge downstream of the crest. These downwelling and upwelling flows form the hyporheic exchange, which is vital for the embryos’ development because it regulates the egg pocket temperature regime and delivers oxygen-rich surface water to the embryos. Here, we experimentally investigate the effects of (1) redd surface roughness and (2) egg pocket presence on redd-induced hyporheic flows under different surface hydraulics by constructing a synthetic redd made of transparent grains that allow us to measure freestream, near-bed, and interstitial flow velocities with non-invasive techniques in a recirculating flume. Results indicate that flow through redds is proportional to the squared Froude number, but surface roughness causes this relation to be more complex. The egg pocket, having larger grains than the surrounding matrix, enhances mechanical dispersion, which increases water mixing within the egg pocket and causes convergence of downwelling flows towards the egg pocket. Overall, these results show that river modeling studies focused on salmonid preservation should consider surface roughness as well as varying hydraulic conductivities within the nesting environments.</div></div>","PeriodicalId":7614,"journal":{"name":"Advances in Water Resources","volume":"199 ","pages":"Article 104947"},"PeriodicalIF":4.0,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pore-scale relative permeability and saturation analysis under wide-ranging injection velocity and wettability during primary CO2 injection for geological carbon sequestration","authors":"Muhammad Nasir,&nbsp;Shintaro Matsushita,&nbsp;Kailin Wang,&nbsp;Masayuki Osada,&nbsp;Shu Yamashita,&nbsp;Wilson Susanto,&nbsp;Sotheavuth Sin,&nbsp;Tetsuya Suekane","doi":"10.1016/j.advwatres.2025.104938","DOIUrl":"10.1016/j.advwatres.2025.104938","url":null,"abstract":"<div><div>We performed two-dimensional (2D) pore-scale simulations of primary CO₂ injection using a weakly compressible scheme for geological carbon sequestration (GCS) applications. The aim was to analyze pore-scale relative permeability and saturation of CO₂ under wide-ranging injection velocities and wettabilities. The results show that saturation is highest for viscous fingering, lowest for crossover (− 5.82 &lt; <em>logCa</em>  &lt;   − 4.86; θ &lt; 60°), and remains high in the capillary fingering regime even though the relative permeability of CO₂ is minimum. This trend occurs because saturation is influenced not only by the value of relative permeability but also by the frequency of relative permeability fluctuations. At a low injection velocity and contact angle, frequent permeability fluctuations due to Haines jumps result in high saturation despite the low relative permeability. At intermediate injection velocity and low contact angle, both the relative permeability and its fluctuations are moderate, leading to lower CO₂ saturation. The present work bridges the understanding of displacement-front advancement at the pore-network scale with relative permeability, which links the pore-scale meniscus dynamics with the large-scale Darcy-flow parameters. As the CO₂ flows away from the injection site in large-scale GCS applications, the displacement pattern exhibits crossover regime, resulting in minimal displacement efficiency. In a strongly wetting porous medium, this condition is severe because crossover regime spans a wide range of capillary numbers.</div></div>","PeriodicalId":7614,"journal":{"name":"Advances in Water Resources","volume":"199 ","pages":"Article 104938"},"PeriodicalIF":4.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Dupuit-Forchheimer solution to the extraction of seawater from coastal aquifers","authors":"Anthony D. Miller ,&nbsp;Amir Jazayeri ,&nbsp;S. Cristina Solórzano-Rivas ,&nbsp;Adrian D. Werner","doi":"10.1016/j.advwatres.2025.104937","DOIUrl":"10.1016/j.advwatres.2025.104937","url":null,"abstract":"<div><div>Seawater intrusion can be mitigated by extracting saltwater, creating a negative hydraulic barrier that reduces the extent of saltwater in coastal aquifers. The effects of seawater extraction are analyzed in the current study through a semi-analytical methodology based on sharp-interface, steady-state conditions. The methodology is based on the Dupuit-Forchheimer approximation and applies a power series approach to obtain an exact solution to the seawater extent in the aquifer. Alternatively, the solution can be obtained by a Runge-Kutta method, thereby allowing for rapid assessment of the efficacy of seawater extraction for simple situations (e.g., uniform, homogeneous aquifer, and a continuous line sink well). Comparisons with numerical simulations using SEAWAT (including cases with nominally zero dispersion and with dispersion) display good agreement between the sharp-interface solution using a modified density and the 50 % seawater contour from SEAWAT. The results show that for a given well location there is an optimal (maximum) extraction rate of seawater that minimises the landward extent of seawater. Equivalently, for a given extraction rate, there is an optimal well location. These optima place a well at the seawater-freshwater interface, so in practice will likely lead to the partial extraction of freshwater. Nonetheless, they represent the limits defining the operating region for a negative hydraulic barrier in non-dimensional parameter space and thereby can inform initial decisions regarding applicability. The method presented provides a rapid assessment tool for examining the interplay between the extraction well location and the extraction rate.</div></div>","PeriodicalId":7614,"journal":{"name":"Advances in Water Resources","volume":"199 ","pages":"Article 104937"},"PeriodicalIF":4.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Salinity effects on fines migration in aquifers: Stochastic model and its upscaling","authors":"C. Nguyen,&nbsp;Y. Yang,&nbsp;G. Loi,&nbsp;T. Russell,&nbsp;P. Bedrikovetsky","doi":"10.1016/j.advwatres.2025.104932","DOIUrl":"10.1016/j.advwatres.2025.104932","url":null,"abstract":"<div><div>Colloidal-suspension-nano flows with varying ionic strength are widely present in nature and industry. The variation of brine salinity, which highly affects electrostatic particle-rock interaction, triggers fines detachment and consequent rock alteration. The microscale models for fines detachment at the pore-particle and at rock-reservoir scales are widely used to predict core and field behaviour under fines migration, while the relationship between those models hasn't been established. This includes the lack of upscaling and downscaling procedures, which prevents the determination of micro-scale parameters from lab corefloods or well production histories and calculation of large-scale model functions from SEM and microfluid tests. In this work for the first time, we derive the rock-scale detachment model as expressed as a function of maximum attached concentration versus brine salinity (maximum retention function MRF) from particle-scale torque balance of attaching and detaching forces. Reflecting micro heterogeneity of the pore space and attached particles, we consider the mutual probabilistic distributions of geometric and electrostatic coefficients from the torque balance of detaching drag and attaching electrostatic DLVO forces exerting the particle. This determines the cumulative distribution of critical salinity, which is calculated from the torque balance and the mutual distribution of microscale parameters and defines the salinity-dependent MRF. This upscaling procedure is performed by the Monte Carlo algorithm for MRF calculation. The corresponding downscaling comprises tuning the mean and variance values for some micro-scale parameters from the MRF. These algorithms are used to treat three coreflood data sets with varying salinity, determine the MRF, and calculate mean values of lever arm and aspect ratios; the match is high, and the obtained microscale parameters are within the common intervals. The upscaling technique developed allows for sensitivity analysis of detachment with respect to microscale parameters and velocity. We also developed the upscaling procedure for MRF recalculation from dependency of one flow parameter to another. The velocity-dependent MRF was recalculated from three coreflood-based salinity-dependent MRFs, yielding lab-based prediction of well behaviour for water injectors and producers.</div></div>","PeriodicalId":7614,"journal":{"name":"Advances in Water Resources","volume":"199 ","pages":"Article 104932"},"PeriodicalIF":4.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A phase-field approach to model evaporation from porous media: Modeling and upscaling","authors":"Tufan Ghosh ,&nbsp;Carina Bringedal ,&nbsp;Christian Rohde ,&nbsp;Rainer Helmig","doi":"10.1016/j.advwatres.2025.104922","DOIUrl":"10.1016/j.advwatres.2025.104922","url":null,"abstract":"<div><div>We develop a phase-field model for evaporation from a porous medium by explicitly considering a vapor component together with the liquid and gas phases in the system. The phase-field model consists of the conservation of mass (for phases and vapor component), momentum, and energy. In addition, the evolution of the phase field is described by the Allen–Cahn equation. In the limit of vanishing interface width, matched asymptotic expansions reveal that the phase-field model reduces to the sharp-interface model with all the relevant transmission conditions on the moving interface. An energy estimate is derived, which suggests that for the diffusion-dominated regime, energy always decreases with time. However, this is not trivial in the case of other regimes. Through numerical examples, we analyze the efficiency of the developed phase-field formulation in modeling the evaporation process. We observe that our formulation is able to capture shrinking liquid droplet, in other words evaporation. Further, the phase-field model is upscaled to the Darcy scale using periodic homogenization for the diffusion-dominated regime. The effective parameters at the Darcy scale are connected to the pore scale through corresponding cell problems.</div></div>","PeriodicalId":7614,"journal":{"name":"Advances in Water Resources","volume":"199 ","pages":"Article 104922"},"PeriodicalIF":4.0,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effective permeability of fluvial lithofacies in the Bunter Sandstone Formation, UK","authors":"Shakhawat Hossain ,&nbsp;Gary J. Hampson ,&nbsp;Carl Jacquemyn ,&nbsp;Matthew D. Jackson ,&nbsp;Dmytro Petrovskyy ,&nbsp;Sebastian Geiger ,&nbsp;Julio D. Machado Silva ,&nbsp;Sicilia Judice ,&nbsp;Fazilatur Rahman ,&nbsp;M. Costa Sousa","doi":"10.1016/j.advwatres.2025.104936","DOIUrl":"10.1016/j.advwatres.2025.104936","url":null,"abstract":"<div><div>Understanding effective permeability is crucial for predicting fluid migration and trapping in subsurface reservoirs. The Bunter Sandstone of northwestern Europe hosts major groundwater and geothermal resources and is targeted for CO₂ storage projects. Here the effective permeability of fluvial facies within the Bunter Sandstone Formation was assessed using facies-scale models. Twelve lithofacies were modeled based on core and outcrop observations of their geometries and dimensions. Permeability values from minipermeameter measurements were assigned to low- and high-permeability lithologies in each facies. The dimensions of a Representative Elementary Volume (REV) in depositional dip, depositional strike and vertical directions were determined by extracting sub-volumes from the models at different scales, calculating values of effective permeability for each sub-volume, and identifying the sub-volume at which the values of effective permeability stabilise as the REV. The REV dimensions vary with facies type and flow direction, but are typically of order tens of centimetres to metres in size, significantly larger than a typical core plug. Having identified the REV, we analyze the effective permeabilities of the different facies types. Normalized values of effective permeabilities in depositional dip, strike and vertical directions (<em>k_d, k_s, k_v</em>), relative to the permeability of low- and high-permeability lithologies in each facies, display a positive linear correlation with the proportion of high-permeability lithology (clay-poor sandstone) for all facies. Therefore, the proportion of clay-poor sandstone, as measured in core data, can be used to predict facies-scale effective permeability in the Bunter Sandstone Formation, as well as in analogous fluvial deposits globally.</div></div>","PeriodicalId":7614,"journal":{"name":"Advances in Water Resources","volume":"199 ","pages":"Article 104936"},"PeriodicalIF":4.0,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New insights into the nonmonotonic wetting effect: The principle of minimum operating power during two-phase displacement","authors":"Xiaokang Guo","doi":"10.1016/j.advwatres.2025.104935","DOIUrl":"10.1016/j.advwatres.2025.104935","url":null,"abstract":"<div><div>In this study, based on the minimum operating power principle, the potential control mechanism of nonmonotonic wetting effects in porous media is analyzed. When different wetting conditions are applied to the system, the contribution weights of different energy contribution terms are different during the process when the system approaches the minimum operating power state. For weak drainage or weak imbibition wetting systems, the contribution weights of the solid‒liquid and liquid‒liquid surface energy change rates are comparable. The system may have a series of stages in which the solid‒liquid and liquid‒liquid surface energy change rates alternate in dominance, which lays a foundation for the existence of a capillary energy barrier regulatory mechanism. In addition, during interfacial reconstruction, the solid‒liquid surface energy change rate in high specific surface area regions plays a dominant role, resulting in a cooperative mechanism (Haines jump events) and noncooperative mechanisms (contact, overlap events), which also establishes a basis for the formation of preferential flow paths and compact displacement states. However, for strong imbibition wetting systems, the contribution weight of the solid‒liquid surface energy change rate begins to dominate, and the capillary energy barrier regulatory mechanism disappears. The system maximizes the solid‒liquid surface energy change rate to approach the minimum operating power state, resulting in an arc meniscus at surface grooves or pore corners with a much higher advancing speed than that of the terminal meniscus. The preferential flow path state dominated by the arc meniscus reappears.</div></div>","PeriodicalId":7614,"journal":{"name":"Advances in Water Resources","volume":"199 ","pages":"Article 104935"},"PeriodicalIF":4.0,"publicationDate":"2025-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of tides and subsurface dams on the land-sourced contaminant transport: Laboratory and numerical investigation","authors":"Jina Yin ,&nbsp;Yunshu Wu ,&nbsp;Jiangjiang Zhang ,&nbsp;Tongchao Nan ,&nbsp;Chunhui Lu","doi":"10.1016/j.advwatres.2025.104921","DOIUrl":"10.1016/j.advwatres.2025.104921","url":null,"abstract":"<div><div>The presence of tides and subsurface dams adds complexity to the migration and mixing processes of land-sourced contaminant in coastal aquifers. While prior studies have explored individual effect of tides and subsurface dams, their combined impact on the transport characteristics of land-sourced contaminant remains unclear. This study conducted laboratory experiments and numerical simulations to thoroughly investigate the migration and discharge behaviors of land-sourced contaminant in an unconfined coastal aquifer. Spatiotemporal variation, transport pathways, spreading, residence time and mass fluxes were analyzed considering effects of tides and subsurface dams. Results demonstrate that a large low-velocity zone forms near the bottom corner upstream of the dam, and the contaminant mixing with residual saltwater in this zone substantially delays its discharge to the ocean. Compared to the nontidal condition, tides enhance seawater circulation within the saltwater wedge and shorten the transit time by 1.5 times while slowing particle transport in the freshwater zone. Moreover, increased tidal amplitude induces a time lag of 9000 s in the peak efflux. The residence time of contaminant is jointly affected by the subsurface dam, saltwater wedge and tidal forces. Sensitivity analysis indicates that a greater aquifer permeability and lower contaminant dispersiviy reduce the maximum spreading area while significantly promoting the maximum daily contaminant efflux. However, the residence time exhibits non‐monotonic relationships with respect to dam locations and aquifer permeabilities. The findings highlight the complexity of nearshore subsurface systems subjected to both natural and human factors, and have valuable insights for developing effective strategies to safeguard coastal environments.</div></div>","PeriodicalId":7614,"journal":{"name":"Advances in Water Resources","volume":"199 ","pages":"Article 104921"},"PeriodicalIF":4.0,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}