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Publisher: Elsevier   (Total: 3183 journals)

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Showing 1 - 200 of 3183 Journals sorted alphabetically
Academic Pediatrics     Hybrid Journal   (Followers: 37, SJR: 1.655, CiteScore: 2)
Academic Radiology     Hybrid Journal   (Followers: 26, SJR: 1.015, CiteScore: 2)
Accident Analysis & Prevention     Partially Free   (Followers: 100, SJR: 1.462, CiteScore: 3)
Accounting Forum     Hybrid Journal   (Followers: 28, SJR: 0.932, CiteScore: 2)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 39, SJR: 1.771, CiteScore: 3)
Achievements in the Life Sciences     Open Access   (Followers: 6)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 7)
Acta Astronautica     Hybrid Journal   (Followers: 437, SJR: 0.758, CiteScore: 2)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 2)
Acta Biomaterialia     Hybrid Journal   (Followers: 28, SJR: 1.967, CiteScore: 7)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 3)
Acta de Investigación Psicológica     Open Access   (Followers: 3)
Acta Ecologica Sinica     Open Access   (Followers: 11, SJR: 0.18, CiteScore: 1)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.661, CiteScore: 2)
Acta Materialia     Hybrid Journal   (Followers: 302, SJR: 3.263, CiteScore: 6)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.504, CiteScore: 1)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.542, CiteScore: 1)
Acta Oecologica     Hybrid Journal   (Followers: 12, SJR: 0.834, CiteScore: 2)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription  
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 2, SJR: 0.307, CiteScore: 0)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 1, SJR: 1.793, CiteScore: 6)
Acta Poética     Open Access   (Followers: 4, SJR: 0.101, CiteScore: 0)
Acta Psychologica     Hybrid Journal   (Followers: 25, SJR: 1.331, CiteScore: 2)
Acta Sociológica     Open Access   (Followers: 1)
Acta Tropica     Hybrid Journal   (Followers: 6, SJR: 1.052, CiteScore: 2)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 3, SJR: 0.374, CiteScore: 1)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 2)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 3, SJR: 0.344, CiteScore: 1)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 1)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 7, SJR: 0.19, CiteScore: 0)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 3)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 8)
Acute Pain     Full-text available via subscription   (Followers: 15, SJR: 2.671, CiteScore: 5)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.53, CiteScore: 4)
Addictive Behaviors     Hybrid Journal   (Followers: 17, SJR: 1.29, CiteScore: 3)
Addictive Behaviors Reports     Open Access   (Followers: 9, SJR: 0.755, CiteScore: 2)
Additive Manufacturing     Hybrid Journal   (Followers: 11, SJR: 2.611, CiteScore: 8)
Additives for Polymers     Full-text available via subscription   (Followers: 23)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 182, SJR: 4.09, CiteScore: 13)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 12, SJR: 1.167, CiteScore: 4)
Advanced Powder Technology     Hybrid Journal   (Followers: 17, SJR: 0.694, CiteScore: 3)
Advances in Accounting     Hybrid Journal   (Followers: 9, SJR: 0.277, CiteScore: 1)
Advances in Agronomy     Full-text available via subscription   (Followers: 17, SJR: 2.384, CiteScore: 5)
Advances in Anesthesia     Full-text available via subscription   (Followers: 29, SJR: 0.126, CiteScore: 0)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 2)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 11, SJR: 0.992, CiteScore: 1)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 11, SJR: 1.551, CiteScore: 4)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 24, SJR: 2.089, CiteScore: 5)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 15, SJR: 0.572, CiteScore: 2)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.61, CiteScore: 7)
Advances in Botanical Research     Full-text available via subscription   (Followers: 2, SJR: 0.686, CiteScore: 2)
Advances in Cancer Research     Full-text available via subscription   (Followers: 33, SJR: 3.043, CiteScore: 6)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 1.453, CiteScore: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 1.992, CiteScore: 5)
Advances in Cell Aging and Gerontology     Full-text available via subscription   (Followers: 5)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 14)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 29, SJR: 0.156, CiteScore: 1)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.713, CiteScore: 1)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 10, SJR: 1.316, CiteScore: 2)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 26, SJR: 1.562, CiteScore: 3)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 20, SJR: 1.977, CiteScore: 8)
Advances in Computers     Full-text available via subscription   (Followers: 14, SJR: 0.205, CiteScore: 1)
Advances in Dermatology     Full-text available via subscription   (Followers: 15)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 13)
Advances in Digestive Medicine     Open Access   (Followers: 12)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 7)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Ecological Research     Full-text available via subscription   (Followers: 44, SJR: 2.524, CiteScore: 4)
Advances in Engineering Software     Hybrid Journal   (Followers: 29, SJR: 1.159, CiteScore: 4)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 8)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 50, SJR: 5.39, CiteScore: 8)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 1)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 65, SJR: 0.591, CiteScore: 2)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Genetics     Full-text available via subscription   (Followers: 21, SJR: 1.354, CiteScore: 4)
Advances in Genome Biology     Full-text available via subscription   (Followers: 10, SJR: 12.74, CiteScore: 13)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 1.193, CiteScore: 3)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 26, SJR: 0.368, CiteScore: 1)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11, SJR: 0.749, CiteScore: 3)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 24)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 3, SJR: 0.193, CiteScore: 0)
Advances in Immunology     Full-text available via subscription   (Followers: 36, SJR: 4.433, CiteScore: 6)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 10, SJR: 1.163, CiteScore: 2)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 2, SJR: 1.938, CiteScore: 3)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 6, SJR: 0.176, CiteScore: 0)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 3)
Advances in Life Course Research     Hybrid Journal   (Followers: 9, SJR: 0.682, CiteScore: 2)
Advances in Lipobiology     Full-text available via subscription   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Marine Biology     Full-text available via subscription   (Followers: 20, SJR: 0.88, CiteScore: 2)
Advances in Mathematics     Full-text available via subscription   (Followers: 12, SJR: 3.027, CiteScore: 2)
Advances in Medical Sciences     Hybrid Journal   (Followers: 8, SJR: 0.694, CiteScore: 2)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.158, CiteScore: 3)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 23)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 8)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 7, SJR: 0.182, CiteScore: 0)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 5)
Advances in Oncobiology     Full-text available via subscription   (Followers: 2)
Advances in Organ Biology     Full-text available via subscription   (Followers: 2)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 18, SJR: 1.875, CiteScore: 4)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.174, CiteScore: 0)
Advances in Parasitology     Full-text available via subscription   (Followers: 5, SJR: 1.579, CiteScore: 4)
Advances in Pediatrics     Full-text available via subscription   (Followers: 26, SJR: 0.461, CiteScore: 1)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 17)
Advances in Pharmacology     Full-text available via subscription   (Followers: 16, SJR: 1.536, CiteScore: 3)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 0.574, CiteScore: 1)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.109, CiteScore: 1)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 10)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 6)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20, SJR: 0.791, CiteScore: 2)
Advances in Psychology     Full-text available via subscription   (Followers: 66)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 6, SJR: 0.371, CiteScore: 1)
Advances in Radiation Oncology     Open Access   (Followers: 1, SJR: 0.263, CiteScore: 1)
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 3, SJR: 0.101, CiteScore: 0)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 6)
Advances in Space Research     Full-text available via subscription   (Followers: 419, SJR: 0.569, CiteScore: 2)
Advances in Structural Biology     Full-text available via subscription   (Followers: 5)
Advances in Surgery     Full-text available via subscription   (Followers: 13, SJR: 0.555, CiteScore: 2)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 37, SJR: 2.208, CiteScore: 4)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 20)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 15)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 2.262, CiteScore: 5)
Advances in Water Resources     Hybrid Journal   (Followers: 53, SJR: 1.551, CiteScore: 3)
Aeolian Research     Hybrid Journal   (Followers: 6, SJR: 1.117, CiteScore: 3)
Aerospace Science and Technology     Hybrid Journal   (Followers: 385, SJR: 0.796, CiteScore: 3)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.42, CiteScore: 2)
African J. of Emergency Medicine     Open Access   (Followers: 6, SJR: 0.296, CiteScore: 0)
Ageing Research Reviews     Hybrid Journal   (Followers: 12, SJR: 3.671, CiteScore: 9)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 472, SJR: 1.238, CiteScore: 3)
Agri Gene     Hybrid Journal   (Followers: 1, SJR: 0.13, CiteScore: 0)
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 17, SJR: 1.818, CiteScore: 5)
Agricultural Systems     Hybrid Journal   (Followers: 31, SJR: 1.156, CiteScore: 4)
Agricultural Water Management     Hybrid Journal   (Followers: 45, SJR: 1.272, CiteScore: 3)
Agriculture and Agricultural Science Procedia     Open Access   (Followers: 4)
Agriculture and Natural Resources     Open Access   (Followers: 3)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 58, SJR: 1.747, CiteScore: 4)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.589, CiteScore: 3)
Air Medical J.     Hybrid Journal   (Followers: 7, SJR: 0.26, CiteScore: 0)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.19, CiteScore: 0)
Alcohol     Hybrid Journal   (Followers: 12, SJR: 1.153, CiteScore: 3)
Alcoholism and Drug Addiction     Open Access   (Followers: 11)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 2, SJR: 0.604, CiteScore: 3)
Alexandria J. of Medicine     Open Access   (Followers: 1, SJR: 0.191, CiteScore: 1)
Algal Research     Partially Free   (Followers: 11, SJR: 1.142, CiteScore: 4)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.504, CiteScore: 1)
Allergology Intl.     Open Access   (Followers: 5, SJR: 1.148, CiteScore: 2)
Alpha Omegan     Full-text available via subscription   (SJR: 3.521, CiteScore: 6)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 10, SJR: 0.201, CiteScore: 1)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 54, SJR: 4.66, CiteScore: 10)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 6, SJR: 1.796, CiteScore: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 6, SJR: 1.108, CiteScore: 3)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 5)
American Heart J.     Hybrid Journal   (Followers: 58, SJR: 3.267, CiteScore: 4)
American J. of Cardiology     Hybrid Journal   (Followers: 63, SJR: 1.93, CiteScore: 3)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 46, SJR: 0.604, CiteScore: 1)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 12)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, SJR: 1.524, CiteScore: 3)
American J. of Human Genetics     Hybrid Journal   (Followers: 36, SJR: 7.45, CiteScore: 8)
American J. of Infection Control     Hybrid Journal   (Followers: 29, SJR: 1.062, CiteScore: 2)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 36, SJR: 2.973, CiteScore: 4)
American J. of Medicine     Hybrid Journal   (Followers: 51)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3, SJR: 1.967, CiteScore: 2)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 249, SJR: 2.7, CiteScore: 4)
American J. of Ophthalmology     Hybrid Journal   (Followers: 66, SJR: 3.184, CiteScore: 4)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 5, SJR: 0.265, CiteScore: 0)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.289, CiteScore: 1)
American J. of Otolaryngology     Hybrid Journal   (Followers: 25, SJR: 0.59, CiteScore: 1)
American J. of Pathology     Hybrid Journal   (Followers: 32, SJR: 2.139, CiteScore: 4)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 28, SJR: 2.164, CiteScore: 4)
American J. of Surgery     Hybrid Journal   (Followers: 39, SJR: 1.141, CiteScore: 2)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.767, CiteScore: 1)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 7)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.144, CiteScore: 3)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 66, SJR: 0.138, CiteScore: 0)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 24, SJR: 0.411, CiteScore: 1)
Anales de Cirugia Vascular     Full-text available via subscription   (Followers: 1)
Anales de Pediatría     Full-text available via subscription   (Followers: 3, SJR: 0.277, CiteScore: 0)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription  
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 5, SJR: 4.849, CiteScore: 10)
Analytica Chimica Acta     Hybrid Journal   (Followers: 44, SJR: 1.512, CiteScore: 5)
Analytica Chimica Acta : X     Open Access  
Analytical Biochemistry     Hybrid Journal   (Followers: 208, SJR: 0.633, CiteScore: 2)
Analytical Chemistry Research     Open Access   (Followers: 13, SJR: 0.411, CiteScore: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 14)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 2)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 25, SJR: 0.683, CiteScore: 2)
Angiología     Full-text available via subscription   (SJR: 0.121, CiteScore: 0)
Angiologia e Cirurgia Vascular     Open Access   (Followers: 1, SJR: 0.111, CiteScore: 0)
Animal Behaviour     Hybrid Journal   (Followers: 217, SJR: 1.58, CiteScore: 3)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 6, SJR: 0.937, CiteScore: 2)
Animal Reproduction Science     Hybrid Journal   (Followers: 7, SJR: 0.704, CiteScore: 2)

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Similar Journals
Journal Cover
Advances in Water Resources
Journal Prestige (SJR): 1.551
Citation Impact (citeScore): 3
Number of Followers: 53  
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0309-1708
Published by Elsevier Homepage  [3183 journals]
  • A dynamic data-driven method for dealing with model structural error in
           soil moisture data assimilation
    • Abstract: Publication date: Available online 22 August 2019Source: Advances in Water ResourcesAuthor(s): Qiuru Zhang, Liangsheng Shi, Mauro Holzman, Ming Ye, Yakun Wang, Facundo Carmona, Yuanyuan Zha Attributing to the flexibility in considering various types of observation error and model error, data assimilation has been increasingly applied to dynamically improve soil moisture modelling in many hydrological practices. However, accurate characterization of model error, especially the part caused by defective model structure, presents a significant challenge to the successful implementation of data assimilation. Model structural error has received limited attention relative to parameter and input errors, mainly due to our poor understanding of structural inadequacy and the difficulties in parameterizing structural error. In this paper, we present a dynamic data-driven approach to estimate the model structural error in soil moisture data assimilation without the need for identifying error generation mechanism or specifying particular form for the error model. The error model is based on the Gaussian process regression and then integrated into the ensemble Kalman filter (EnKF) to form a hybrid method for dealing with multi-source model errors. Two variants of the hybrid method in terms of two different error correction manners are proposed. The effectiveness of the proposed method is tested through a suit of synthetic cases and a real-world case. Results demonstrate the potential of the proposed hybrid method for estimating model structural error and providing improved model predictions. Compared to the traditional EnKF without explicitly considering the model structural error, parameter compensation issue is obviously reduced and soil moisture retrieval is substantially improved.
  • The effects of cascade dam construction and operation on riparian
    • Abstract: Publication date: September 2019Source: Advances in Water Resources, Volume 131Author(s): Yu-jun Yi, Yang Zhou, Jie Song, Shanghong Zhang, Yanpeng Cai, Wei Yang, Zhifeng YangABSTRACTRiparian vegetation acts as a corridor, filter, or barrier for the flow of material, energy, and information between terrestrial and aquatic ecosystems. While, dam construction, especially cascade dam construction, bring huge changes to riparian vegetation. In this study, the changing of riparian vegetation cover in response to the construction and operation of large dams at different scale was analyzed. The variations of the normalized difference vegetation index (NDVI) in longitudinal and transverse directions during pre- and post-dam construction were calculated and analyzed. The results showed that dam height was the main determining factor for the range of riparian vegetation affected in the longitudinal direction, whereas valley contour and distance to dam site affect the transverse direction vegetation together. A linear or logarithmic relation between submerged area in transverse and the distance to dam were founded. After dam construction, the NDVI in the valley becomes uniform, and the vegetation grows more homogeneously. Influence extent of different elevation in different reaches was discussed. The intensive affected area including inundated area and 200 m from the water surface in vertical direction. As the altitude grows, the influence gets weak. Positive effect of a single dam on vegetation in upstream reservoir was found except near channel grade, and a potential oligotrophic threat for the downstream vegetation was posted. For cascade dams, the vegetation in the upstream of Xiaowan dam became better from elevation 200–400 m above original water surface. The NDVI between Xiaowan dam and Manwan dam, which at downstream of Xiaowan but in reservoir of Manwan, degraded after Xiaowan dam constructed. Cascade dams have cumulative effects on vegetation, the influence are positive or negative mainly depend on diversion of the dam.
  • Publisher's Note
    • Abstract: Publication date: September 2019Source: Advances in Water Resources, Volume 131Author(s):
  • A Novel Method for Well Placement Design in Groundwater Management:
           Extremal Optimization
    • Abstract: Publication date: Available online 12 August 2019Source: Advances in Water ResourcesAuthor(s): Fleford Redoloza, Liangping Li Well placement design refers to finding the optimal well locations to install with a set of constraints. This is important for both petroleum engineering and water resource management. This study presents a novel optimization method for well placement design in groundwater management. The proposed method, EO-WPP, is based on the Extremal Optimization (EO) algorithm. EO works by modifying the components of a solution that contribute the least to its overall performance. EO-WPP extends the EO algorithm to the fields of groundwater management and well field optimization for the first time. Groundwater Management program (GWM) is coupled with EO-WPP and used to rank wells in terms of pumping rate, given well locations. In the first testing phases of this work, EO-WPP was applied to a problem of simple geometry and a simple synthetic model in order to study its performance and its emergent spatial behaviors. Results show that the proposed method was faster than Particle Swarm Optimization (PSO) and the Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithms. EO-WPP then was applied to a field problem involving the Aberdeen groundwater model in South Dakota. The results show that EO-WPP was able to generate a series of possible of well fields that can be used to pump effectively groundwater from the Elm aquifer.
  • Seawater intrusion and retreat in tidally-affected unconfined aquifers:
           Laboratory experiments and numerical simulations
    • Abstract: Publication date: Available online 9 August 2019Source: Advances in Water ResourcesAuthor(s): Xiayang Yu, Pei Xin, Chunhui Lu Based on combined laboratory experiments and numerical simulations, this paper examined seawater intrusion (SWI) and seawater retreat (SWR) processes caused by abrupt inland watertable changes in a laboratory-scale unconfined aquifer (length of 7.7 m and thickness of 1.0 m) subjected to a synthetic sinusoidal tide. The results showed that the salinity distribution was relatively stable and that SWI and SWR processes were almost temporally symmetrical given relatively large horizontal hydraulic gradients (0.0269, 0.0209 and 0.0149) between the inland watertable and the mean sea level. However, the salt distribution changed significantly in response to the inland watertable variations when the horizontal hydraulic gradient was relatively small (0.0030). The speed of the SWI and SWR response to the inland watertable variations was temporally asymmetric, e.g., SWR was quicker than SWI by a factor of 9 with respect to the observed saltwater wedge toe locations. As a relatively thick mixing zone (transition between freshwater and saltwater zones) was induced by the tide, simulated saltwater wedge toe locations, as indicated by the 5%, 50% and 95% isohalines, changed inconsistently. Different hysteresis behaviors were found in the relationship between the SW toe locations and total salt mass stored in the aquifer. Sensitivity analyses demonstrated that the response of both SWI and SWR to the inland watertable variations could be prolonged by a decreased tidal amplitude or decreased tidal period.
  • A model of local thermal non-equilibrium during infiltration
    • Abstract: Publication date: Available online 9 August 2019Source: Advances in Water ResourcesAuthor(s): Thomas Heinze, Johanna R. Blöcher A realistic temperature estimation is crucial for many earth-science applications, ranging from hydro-thermal systems to plant physiology. The most common approach to calculate the temperature in multi-phase systems assumes immediate local thermal equilibrium (LTE) between the phases. However, local thermal equilibrium between the phases is not applicable in various scenarios like during the infiltration of rain or melt water in frozen soil, limiting the applicability of the approach and inhibiting the implementation of separate initial and boundary conditions for non-equilibrium situations. In local thermal non-equilibrium (LTNE) models, phase temperatures are described separately to the cost of additional differential equations and an explicitly formulated heat transfer between the phases. Especially a cumbersome parameterization of the explicit heat transfer restricts the use of the LTNE models in multi-phase conditions so far. In this work, we derive a general local thermal non-equilibrium model for dynamic, partly saturated porous media. Heat transfer between the phases is described explicitly using well-known semi-empirical parameterization accounting for velocity changes of the mobile phases. The change in volume fraction introduces an additional term in the heat equation, causing a coupling with the hydraulic model. We validate our model with a numerical simulation of historic experimental data from soil infiltration experiments of warm and cold water into drained soil, posing a perfect example of local thermal non-equilibrium conditions between the phases. Experimentally obtained mixture temperatures are reproduced within experimental accuracy. We further show the benefits of our model by applying it to rainwater infiltration into cold soil. Besides a consistent formulation of initial and boundary conditions, the derived model allows physically based conclusions about the thermal state of the separate phases.
  • Effect of aperture field anisotropy on two-phase flow in rough fractures
    • Abstract: Publication date: Available online 7 August 2019Source: Advances in Water ResourcesAuthor(s): Zhibing Yang, Dongqi Li, Song Xue, Ran Hu, Yi-Feng Chen The void space geometry of rough fractures is one of most important factors controlling two-phase flow in fractured media. This paper presents a numerical study on the effect of aperture field anisotropy on two-phase flow properties in rough fractures. By using a power spectrum based method, we generate multiple realizations of synthetic rough fractures with aperture fields of different anisotropy factors. Fluid–fluid displacement in these fractures is simulated by a modified invasion percolation model. It is found that the spatiotemporal distribution of fluid phases is strongly influenced by the aperture field anisotropy. On average, both the nonwetting phase saturation and the entrapped wetting phase saturations at breakthrough decrease with increasing anisotropy factor; but the specific interfacial area is larger for a higher anisotropy ratio. Relative permeabilities to both phases in the direction parallel to the displacement increase with the anisotropy factor, indicating a reduced phase interference due to aperture field anisotropy. Empirical equations are proposed to link the relative permeabilities to the anisotropy factor. These results improve our understanding of immiscible displacement in rough fractures and can be useful for predicting two-phase flow in fractured media at the large scale where geomechanical and chemical processes produce anisotropic roughness.
  • Dam break in rectangular channels with different upstream-downstream
    • Abstract: Publication date: Available online 5 August 2019Source: Advances in Water ResourcesAuthor(s): A. Valiani, V. Caleffi The classic Stoker dam-break problem (Stoker, 1957) is revisited in cases of different channel widths upstream and downstream of the dam. The channel is supposed to have a rectangular cross section and a horizontal and frictionless bottom. The system of the shallow water equations is enriched, using the width as a space-dependent variable, together with the depth and the unit discharge, which conversely depend on both space and time. Such a formulation allows a quasi-analytical treatment of the system, whose solution is similar to that of the classic Stoker solution when the downstream/upstream depth ratio is sufficiently large, except that a further stationary contact wave exists at the dam position. When the downstream/upstream depth ratio is small, the solution is richer than the Stoker solution because the critical state occurs at the dam position and the solution itself becomes resonant at the same position, where two eigenvalues are null and the strict hyperbolicity of the system is lost. The limits that identify the flow regime for channel contraction and channel expansion are discussed after showing that the nondimensional parameters governing the problem are the downstream/upstream width ratio and the downstream/upstream initial depth ratio.After the introduction of the previous analytical framework, a numerical analysis is also performed to evaluate a numerical method that is conceived to suitably capture rarefactions, shock waves and contact waves. A second-order method is adopted, employing a Dumbser-Osher-Toro Riemann solver equipped with a nonlinear path. Such an original nonlinear path is shown to perform better than the classic linear path when contact waves of large amplitude must be captured, being able to obtain specific energy conservation and mass conservation at the singularity.The codes, written in MATLAB (MathWorks Inc.) language, are made available in Mendeley Data repository.
  • Contribution of the main moisture sources to precipitation during extreme
           peak precipitation months
    • Abstract: Publication date: Available online 3 August 2019Source: Advances in Water ResourcesAuthor(s): Raquel Nieto, Danica Ciric, Marta Vázquez, Margarida L.R. Liberato, Luis Gimeno A worldwide study is presented to understand the role of major global moisture source regions in the occurrence of extreme monthly precipitation over the continents. The Lagrangian model FLEXPART v9.0 was used to analyse the moisture transport for precipitation, and the extreme precipitation was calculated for each grid point (at 0.25°) using the Multi-Source Weighted-Ensemble Precipitation (MSWEP) monthly precipitation dataset. Although the eventual aim of this work is to show the link between the contributions from the sources to their sinks during months of extreme rainfall, we provide, for the first time, much-needed information on these contributions at a monthly scale – previously this information was only available at an annual scale. We also provide maps showing global monthly moisture sources, together with the identification of the peak precipitation month (PPM) and of the preferred moisture source for precipitation in that month.Graphical abstractImage, graphical abstract
  • Identifying spatiotemporal variations in groundwater-surface water
    • Abstract: Publication date: Available online 3 August 2019Source: Advances in Water ResourcesAuthor(s): Noa Hillel, Michael L. Wine, Jonathan B. Laronne, Tobias Licha, Yaron Be'eri-Shlevin, Christian Siebert Groundwater-surface water interactions as result of in- and effluent conditions along a stream may have a strong impact on the quantity and quality of the river water. These interactions are controlled by river morphology and by transient hydraulic gradients between river and surrounding groundwater. Here we document the existence of spatiotemporal variations in groundwater-surface water interactions in the bed of the Lower Jordan River through pore water analysis of shallow sediment cores using major ions (Na+, Mg2+, Ca2+, Cl−, Br−, SO42−) and stable isotopes (δ18O, δ2H). Our results demonstrate that temporal variations are neither spatially uniform nor steady. Upwelling of groundwater is seasonally dependent and forced by a winter pulse of groundwater recharge and by estival low river discharge.
  • Vertically-Averaged and Moment Equations for Flow and Sediment Transport
    • Abstract: Publication date: Available online 3 August 2019Source: Advances in Water ResourcesAuthor(s): Francisco n. Cantero-chinchilla, Oscar Castro-Orgaz, Abdul a. Khan Simulation of river flow processes including sediment transport is usually conducted using the shallow water flow equations, which are based on a hydrostatic pressure distribution. To increase the accuracy of predictions in a variety of scenarios involving horizontal length scales of the order of vertical length scales, an improved representation of the vertical flow structure is necessary. The mathematical approximation to field variables like the velocity and fluid pressure must be enhanced during the depth-integrating process. Therefore, this paper presents a 1D non-hydrostatic flow and sediment transport model developed by using the method of the weighted residuals into the RANS equations. Using continuity, momentum, and moment equations, the fluid pressure distribution is modelled using a quadratic predictor with perturbation parameters to deviate the vertical momentum balance from the hydrostatic law. The flow equations are a generalized non-hydrostatic flow solver, where the fluid density variation due to suspension of sediments and the bed deformation due to erosion-sedimentation processes are accounted for. A hybrid semi-implicit finite volume-finite difference numerical scheme is developed to solve the system of conservation laws. Two different approaches are used to model the sediment transport processes: (i) Unified computation of the total-load transport and (ii) separate computation of suspended and bed loads. The accuracy of the non-hydrostatic model is demonstrated by comparison with experimental data, highlighting better results accounting for separate determinations of the suspended and bed loads in highly erosive flows.Graphical Image, graphical abstract
  • Aging and mixing as pseudo-chemical-reactions between, and on, particles:
           Perspectives on particle interaction and multi-modal ages in hillslopes
           and streams
    • Abstract: Publication date: Available online 2 August 2019Source: Advances in Water ResourcesAuthor(s): David A. Benson, Michael J. Schmidt, Diogo Bolster, Ciaran Harmon, Nicholas B. Engdahl The particle-tracking method was recently extended to allow inter-particle mass transfer and arbitrarily complex reactions by allowing each particle to represent any number of distinct chemical compounds. This methodology allows the tracking (and broadening due to mixing) of the age probability density function (PDF) on each particle. Aquifer heterogeneity leads to channeling and multi-modal age PDFs in stream samples. This observation supports the concept of age classes but clearly shows the more complicated interplay of dispersion, mixing, and travel times on the age distributions.
  • Multi-phase flow modeling of submarine landslides: Transformation from
           hyperconcentrated flows into turbidity currents
    • Abstract: Publication date: Available online 30 July 2019Source: Advances in Water ResourcesAuthor(s): Cheng-Hsien Lee Sedimentary density flows are major agents of sediment transport on oceans. Occurring after submarine landslides, the sedimentary density flows experience a series of dilution processes. Such flows, then, transform from the hyperconcentrated flows into the concentrated ones, and finally turn into the turbidity currents. This study applies a sophisticated multi-phase flow model to simulate sedimentary density flows caused by submarine granular landslides over a simplified topography with an emphasis on their dilution mechanisms. This model takes account of the particle-particle interactions, the particle-fluid interactions, and the turbulent motions of fluid and particles in the momentum transports. The two effects on turbulence modulation are considered: one is due to the stratification and the other is caused by the correlation between the fluid and sediment turbulent motions. The numerical results suggest that the dilution mechanisms are highly related to Kelvin-Helmholtz vortices. In addition to erosion of the hyperconcentrated region by vortices, this study finds that strong stir in the concentrated region by the vortices is another important dilution mechanism. Compared with the outer regions of the vortices (with zero vorticity), the vortex cores (with non-zero vorticity) have less efficient dilution processes due to rigid-body rotations there. The vortex cores can trap the small particles for a while. The involved flow regimes are also presented. The numerical results reveal that the turbidity currents can be either turbulent or laminar when the Bagnold limit of concentration is adopted to define the boundary of turbidity currents.
  • Dynamic evolution of the soil pore size distribution and its connection to
           soil management and biogeochemical processes
    • Abstract: Publication date: Available online 30 July 2019Source: Advances in Water ResourcesAuthor(s): Norman Pelak, Amilcare Porporato Soil properties are determined by a complex arrangement of pores, particles, and aggregates, which may change in time as a result of both ecohydrological dynamics and land management processes. The soil pore size distribution (PSD), which typically is treated as a static component, is a key determinant of soil properties, and its accurate representation has the potential to improve hydrological and crop models. Following previous work by Or et al. (2000), a modeling framework is proposed for the time evolution of the PSD which takes into account processes such as tillage, consolidation, and changes in organic matter. A time-varying power law PSD is obtained as the solution of a special form of transport equation for the PSD, parameterized using data from the literature to capture, in a parsimonious and efficient manner, the changes in the PSD as a result of the soil processes considered. Alterations in soil properties brought about by tillage, consolidation, and organic matter are then discussed. The potential benefit of this method for determining soil properties over the more widely used pedotransfer functions (PTF) is that it allows for the history of the soil, rather than only its present state, to be taken into account when estimating soil properties, and it does so in a physically consistent manner, leading to the widely used power law expression for soil properties with few parameters.
  • Particle Density Estimation with Grid-Projected and Boundary-Corrected
           Adaptive Kernels
    • Abstract: Publication date: Available online 29 July 2019Source: Advances in Water ResourcesAuthor(s): Guillem Sole-Mari, Diogo Bolster, Daniel Fernàndez-Garcia, Xavier Sanchez-Vila The reconstruction of smooth density fields from scattered data points is a procedure that has multiple applications in a variety of disciplines, including Lagrangian (particle-based) models of solute transport in fluids. In random walk particle tracking (RWPT) simulations, particle density is directly linked to solute concentrations, which is normally the main variable of interest, not just for visualization and post-processing of the results, but also for the computation of non-linear processes, such as chemical reactions. Previous works have shown the improved nature of kernel density estimation (KDE) over other methods such as binning, in terms of its ability to accurately estimate the “true” particle density relying on a limited amount of information. Here, we develop a grid-projected KDE methodology to determine particle densities by applying kernel smoothing on a pilot binning; this may be seen as a “hybrid” approach between binning and KDE. The kernel bandwidth is optimized locally. Through simple implementation examples, we elucidate several appealing aspects of the proposed approach, including its computational efficiency and the possibility to account for typical boundary conditions, which would otherwise be cumbersome in conventional KDE.
  • Pore-network modelling of non-Darcy flow through heterogeneous porous
    • Abstract: Publication date: Available online 10 July 2019Source: Advances in Water ResourcesAuthor(s): A.A. El-Zehairy, M. Mousavi Nezhad, V. Joekar-Niasar, I. Guymer, N. Kourra, M.A. Williams A pore-network model (PNM) was developed to simulate non-Darcy flow through porous media. This paper investigates the impact of micro-scale heterogeneity of porous media on the inertial flow using pore-network modelling based on micro X-ray Computed Tomography (XCT) data. Laboratory experiments were carried out on a packed glass spheres sample at flow rates from 0.001 to 0.1 l/s. A pore-network was extracted from the 3D XCT scanned volume of the 50 mm diameter sample to verify the reliability of the model. The validated model was used to evaluate the role of micro-heterogeneity in natural rocks samples. The model was also used to investigate the effect of pore heterogeneity on the onset of the non-Darcy flow regime, and to estimate values of the Darcy permeability, Forchheimer coefficient and apparent permeability of the porous media. The numerical results show that the Reynold's number at which nonlinear flow occurs, is up to several orders of magnitude smaller for the heterogeneous porous domain in comparison with that for the homogeneous porous media. For the Estaillades carbonate rock sample, which has a high degree of heterogeneity, the resulting pressure distribution showed that the sample is composed of different zones, poorly connected to each other. The pressure values within each zone are nearly equal and this creates a number of stagnant zones within the sample and reduces the effective area for fluid flow. Consequently, the velocity distribution within the sample ranges from low, in stagnant zones, to high, at the connection between zones, where the inertial effects can be observed at a low pressure gradient.
  • Seasonal and event-based concentration-discharge relationships to identify
           catchment controls on nutrient export regimes
    • Abstract: Publication date: Available online 10 July 2019Source: Advances in Water ResourcesAuthor(s): Camille Minaudo, Rémi Dupas, Chantal Gascuel-Odoux, Vincent Roubeix, Pierre-Alain Danis, Florentina Moatar The analysis of concentration-discharge (C-Q) relationships provides useful information on the processes controlling the mobilization and delivery of chemical elements into streams as well as biogeochemical transformations in river networks. Previous metrics developed to characterize export regimes seldom considered the possibility for the C response to Q dynamics to differ between short-term Q variations during storm events and seasonal Q variations during baseflow periods. Here, we present the “C-Qquick-slow” model, which considers the possibility for C-Q relationships to vary across temporal scales. This model was applied in 219 French catchments with various sizes (11 – 2500 km²), land use and hydrological contexts. We evidenced contrasting export regimes for nitrate (NO3−), total phosphorus (TP) and soluble reactive phosphorus (SRP), and surprisingly consistent C-Q patterns at the seasonal scale for each parameter. For instance, NO3−-Q relationships were positive at the seasonal scale in 75% cases and relationships during storms showed either a dilution pattern (24% cases), a non-significant pattern (50%), or a mobilization pattern (12%). TP and SRP relationships with Q at the seasonal scale were almost systematically negative (95%), and patterns during storm events were in most cases mobilization for TP (77%) or non-significant for SRP (69%). We linked the different C-Q relationships with catchment descriptors and found that indicators of diffuse source loading determined NO3− seasonal amplitudes, and hydrological drivers could explain the behavior during storms. By contrast, point sources determined P seasonal amplitudes, and diffuse sources controlled P dynamics during storms. The C-Qquick-slow model has the potential to improve nutrient load estimations because of the good predictability of appropriate C-Q archetypes and the possibility to interpolate low frequency concentration data to a daily frequency.
  • A Coupled Surface Water Storage and Subsurface Water Dynamics Model in
           SWAT for Characterizing Hydroperiod of Geographically Isolated Wetlands
    • Abstract: Publication date: Available online 10 July 2019Source: Advances in Water ResourcesAuthor(s): Junyu Qi, Xuesong Zhang, Sangchul Lee, Glenn E. Moglen, Ali M. Sadeghid Gregory W. McCarty Wetlands play an important role in watershed hydrology and biogeochemistry. A geographically isolated wetland (GIW) module for Soil and Water Assessment Tool (SWAT) was developed to couple surface water storage and subsurface water dynamics to characterize hydroperiod. The new GIW module includes the following features: (1) a flexible geometric formula to characterize wetland surface water area, volume, and depth; (2) a revised algorithm to account for evaporation from both water and soil surfaces in wetlands; (3) application of the Richards equation to couple surface water storage and subsurface water dynamics; (4) use of Darcy's law with an effective hydraulic conductivity parameter to simulate groundwater discharge. We tested the GIW module using observed daily water level data from four wetlands at two sites (including restored and natural wetlands with and without a low-permeability soil layer) in the Delmarva Peninsula, USA. The results show that the wetland module reasonably reproduced observed water levels for both restored and natural wetlands with and without a low-permeability soil layer. The module was also able to reasonably simulate saturated and unsaturated portions of the soil corresponding to wet and dry periods. The ability of the GIW module to describe inundation conditions for wetlands holds promise to enhance the understanding and quantification of hydrological and biogeochemical roles of GIWs in a watershed context.
  • Experimental analysis of wave attenuation and drag forces in a realistic
           fringe Rhizophora mangrove forest
    • Abstract: Publication date: Available online 10 July 2019Source: Advances in Water ResourcesAuthor(s): Maria Maza, Javier L. Lara, Iñigo J. Losada With the aim of better understand and parameterize the physical processes involved in flow-mangrove interaction, wave attenuation and drag forces along a 1:6 scale fringe Rhizophora mangrove forest are studied experimentally. The 26 m long forest is composed by 135 models built reproducing mature Rhizophora mangrove trees with 24 prop roots. Hydrodynamic conditions are scaled using Froude similarity based on values collected in nature. Regular and random waves are tested and three water depths are considered to account for the influence of variable mangroves frontal area along the vertical. Wave decay analysis highlights the importance of considering the effect of flume bottom and walls friction. Neglecting this additional damping can result in a high overestimation of the mangrove dissipation capacity. It is proven that water depth, and the associated mangroves frontal area, and wave height are the dominant variables driving wave attenuation for short waves. The slope seaward the forest induces wave shoaling leading to an increase of wave steepness. Accordingly, the exerted forces on the mangroves also increase along the first 3 – 4 m of the forest. Smaller forces are recorded further into the forest where wave decay formulations fit well to the recorded wave heights. In general, analytical drag forces obtained by using mangrove trees induced damping coefficients compare well to the forces measured within the forest. However, analytical drag forces can lead to overestimations of up to double in some cases. This aspect is very important when experimental results are used to feed numerical or analytical models based on the introduction of a drag force in the momentum equation. These models should be calibrated using, whenever possible, direct force measurements.
  • Seasonal predictability of high sea level frequency using ENSO patterns
           along the U.S. West Coast
    • Abstract: Publication date: Available online 9 July 2019Source: Advances in Water ResourcesAuthor(s): Abdou Khouakhi, Gabriele Villarini, Wei Zhang, Louise J. Slater High sea levels can be conducive to coastal flooding, coastal erosion and inland salt-water intrusion, and thus pose a significant threat to coastal communities, ecosystems and coastal assets. Increases in high water levels have been attributed largely to rising mean sea levels associated with intra-seasonal to interannual climate modes of variability such as the El Niño-Southern Oscillation (ENSO). Here, we examine the predictability of the seasonal frequency of high sea levels using the Niño3.4 index. Different high sea level quantities are considered at 23 tide gauges along the U.S. West Coast, including storm surge and nuisance (minor) floods. At each site, we develop a statistical probabilistic forecasting model for seasonal high sea level frequency during the cold period of October-March. As predictors, we compare the use of (1) seasonal Niño3.4 index observations over the warm antecedent period of July-September and (2) seasonal Niño3.4 index forecasts from the North American Multi-Model Ensemble (NMME) over the cold concurrent period of October-March. Results indicate that the Niño3.4 observations are a good predictor of seasonal high sea level frequency, especially for predicting the storm surge frequency. Correlation coefficients between the observed and modelled seasonal storm surge frequency range from 0.6 to 0.95 at most of the 23 tide gauges. In the predictive model, when using NMME Niño3.4 index, correlation coefficients range between approximately 0.4 and 0.7 at the southern gauges for Niño3.4 index forecasts initialized from October to June (the skill decreases with lead time). Our results provide insights into the seasonal predictability of high sea levels using ENSO patterns which is important for planning and coastal management.
  • Optimal impoundment operation for cascade reservoirs coupling parallel
    • Abstract: Publication date: Available online 8 July 2019Source: Advances in Water ResourcesAuthor(s): Shaokun He, Shenglian Guo, Kebing Chen, Lele Deng, Zhen Liao, Feng Xiong, Jiabo Yin The optimal impoundment operation of cascade reservoirs can dramatically improve the utilization of water resources. However, their complex non-convexity and computational costs pose challenges to optimal hydroelectricity output and limit further development of joint operation within larger-scale cascade reservoirs. In recent decades, parallel dynamic programming (PDP) has emerged as a means of alleviating the ‘curse of dimensionality’ in the mid-long term reservoir operation with more involved computing processors. But it still can't effectively solve the daily impoundment operation of more than three reservoirs. Here, we propose a novel method called importance sampling-PDP (IS-PDP) algorithm in which the merits of PDP are integrated with importance sampling and successive approximation strategy. Importance sampling is first used to construct the state vectors of each period by introducing ‘Manhattan distance’ in the discrete state space. Then the PDP recursive equation is used to find an improved solution during the iteration. The IS-PDP method is tested to optimize hydropower output for the joint operation of an 11-reservoir system located in the upper Yangtze River basin of China after establishing impoundment operation by advancing impoundment timings and rising water levels. We find that our methodology could effectively deal with the ‘curse of dimensionality’ for such mega reservoir systems and make better use of water resources in comparison to the Standard Operation Policy (SOP). Given its computational efficiency and robust convergence, the methodology is an attractive alternative for non-convex operation of large-scale cascade reservoirs.
  • Anisotropic dispersion with a consistent smoothed particle hydrodynamics
    • Abstract: Publication date: Available online 5 July 2019Source: Advances in Water ResourcesAuthor(s): Carlos E. Alvarado-Rodríguez, Leonardo Di G. Sigalotti, Jaime Klapp A consistent smoothed particle hydrodynamics (SPH) approach is used to simulate the anisotropic dispersion of a solute in porous media. Consistency demands using large numbers of neighbors with increasing resolution. The method is tested against the anisotropic dispersion of a Gaussian contaminant plume. With irregularly distributed particles, the solution for isotropic dispersion converges to second-order accuracy when at sufficiently high resolution a large number of neighbors is used within the kernel support. For low to moderate anisotropy, the convergence rates are close to second-order, while for large anisotropic dispersion the solutions converge to better than first-order. For randomly distributed particles, the solutions are also better than first order independently of the degree of anisotropy. When negative concentrations arise, they are several orders of magnitude smaller than those encountered with standard SPH and comparable to those obtained with the MWSPH scheme of Avesani et al. The method is also insensitive to particle disorder and achieves an overall accuracy comparable to the MWSPH method using a much simpler approach.
  • Improved dynamic programming for parallel reservoir system operation
    • Abstract: Publication date: Available online 4 July 2019Source: Advances in Water ResourcesAuthor(s): Xiang Zeng, Tiesong Hu, Ximing Cai, Yuliang Zhou, Xin Wang Optimizing a multi-reservoir system is challenging due to the problem of the curse of dimensionality. In this paper, rule-based improved dynamic programming (RIDP) and stochastic dynamic programming (RISDP) algorithms for the optimal operation of a system with a number of parallel reservoirs are proposed to alleviate the dimensionality problem. The improvement is based on a key property: the monotonic dependence relationship between individual reservoir carryover storage and system water availability, which is derived with the assumption of the non-decreasing storage distribution characteristic of a parallel reservoir system. Furthermore, a diagnosis procedure is employed to remove infeasible state transitions, which enables the application of the monotonic relationship within the feasible solution space. In general, the computational complexity of (NS)n2 from DP can be reduced to (NS)n from RIDP (NS is the number of storage discretization for individual reservoirs, n is the number of reservoirs in a parallel system), with controlled solution accuracy. The improved algorithms are applied to a real-world parallel reservoir system in northeastern China. The results demonstrate the computational efficiency and effectiveness of RIDP and RISDP.
  • nModeling of 2-D Seepage From Aquifer Towards Stream via Clogged Bed: the
           Toth-Trefftz Legacy Conjugated
    • Abstract: Publication date: Available online 3 July 2019Source: Advances in Water ResourcesAuthor(s): A.R. Kacimov, Yu. V. Obnosov Baseflow-type interaction between a river and adjacent/subjacent aquifer across a thin clogging layer of fine sediments controls the dynamics of surface-pore water resources, quality of both waters, seepage induced erosion of the river bed and other hydrological phenomena. Transient 2D phreatic flow from an unconfined aquifer into a river with a thin low-permeable cake (hydraulic skin) is approximated by a sequence of steady states, each of which assumes the water table to be horizontal. The scalar and vector fields of piezometric head, stream function and Darcian velocity are found from analytical solution of the Dirichlet and Robin (linear combination of the velocity potential and its normal derivative) boundary value problems for the piezometric head (harmonic function). The time-shrinking Tothian “unit basins” are a half-strip, half-plane or rectangle. Stream banks are assumed to be horizontal or vertical segments. Cross-flow from the aquifer into the stream is controlled by the aquifer-skin conductivity ratio and the stages of the river and adjacent aquifer. The head and cross-flux on the interface (Robin's boundary) is shown to vary along this line and therefore even for vertical river banks the Dupuit-Forchheimer approximation is not strictly valid. Numerical simulations in HYDRUS2D are reasonably close to the analytical results. Early-stage drawdown of a rectangular cake due to a sudden drop of the water level on the river side and formation of a seepage face is analysed with potential applications to stability of earth dams.
  • Quantile-based downscaling of rainfall extremes: Notes on methodological
           functionality, associated uncertainty and application in practice
    • Abstract: Publication date: Available online 2 July 2019Source: Advances in Water ResourcesAuthor(s): Elmira Hassanzadeh, Ali Nazemi, Jan Adamowski, Truong-Huy Nguyen, Van-Thanh Van-Nguyen Local characteristics of extreme rainfall quantiles, manifested through Intensity-Duration-Frequency (IDF) curves, are key to infrastructure design. Due to climate change, rainfall extremes are subject to changes, it is, therefore, crucial to explore the potential impacts these changes will have on design storms. A new strain of methodologies, quantile-based downscaling approaches, have recently been proposed to exclusively downscale extreme rainfall quantiles obtained from Global Climate Models (GCMs). These approaches, however, have not been systematically intercompared and the uncertainties related to assigning future design storms are poorly understood. This study evaluates the functionality of three quantile-based downscaling methods during the historical and future periods in Montreal, Canada. Results show that the performance of quantile-based downscaling approaches in reproducing observed extreme quantiles can be divergent. At lower return periods, however, differences between the three schemes are not significant. Similar performances for reproducing historical rainfall extremes, however, does not necessarily imply similar future projections due to the different functionalities of the three approaches in mapping GCM projections into finer scales. Despite these uncertainties, the total projection range of future rainfall extremes are, in many cases, comparable to the confidence interval of the parametric probability distribution when fitted to the observed annual maximum rainfall series. A risk-based approach to accommodate this uncertainty in vulnerability assessments through evaluating potential alterations in historical rainfall extremes using an ensemble projection coming from multiple downscaling approaches is suggested. This allows for the selection of design storms based on the acceptable level of risk and given budgetary and operational restrictions.
  • On Information Coupling in Hybrid ISPH Framework for Fluidized Granular
    • Abstract: Publication date: Available online 26 June 2019Source: Advances in Water ResourcesAuthor(s): Gourabananda Pahar, Anirban Dhar An improved information transfer mechanism is developed to couple fluid and granular modules for Incompressible Smoothed Particle Hydrodynamics modelling of sediment transport. The interaction force pair necessitates effective projection of information among parallel continuum based modules. The particle position in either module is susceptible to considerable variation due to their Lagrangian nature. An attempt has been made to minimize the effective thickness of the diffused interface between the fluid and granular particles. The proposed model reduces artificial drag force resulting from diffused computation of effective porosity. The revised framework outperforms in coarse resolution compared to its existing counterpart.
  • In-situ investigation of the impact of spreading on matrix-fracture
           interactions during three-phase flow in fractured porous media
    • Abstract: Publication date: Available online 28 May 2019Source: Advances in Water ResourcesAuthor(s): Mohammd J. Sabti, Amir H. Alizadeh, Mohammad Piri This paper presents the results of a detailed experimental study performed to examine fluid flow in a water-wet fractured sandstone rock. Using high-resolution X-ray micro computed tomography technique, we systematically investigate the pore-scale displacement mechanisms and governing interactions between the matrix and fracture during gas injection. We perform two sets of flow experiments using brine/Soltrol 170 (spreading oil)/nitrogen and brine/decalin (nonspreading oil)/nitrogen fluid systems to probe the possible beneficial role of spreading phenomena in transferring oil from the matrix to the fracture during gas injection. Gas injection after primary oil drainage was used to generate a wide range of oil saturations and pore fluid arrangements with both fluid systems. Direct visualization of the pore fluid occupancies at different oil saturations in the medium reveals the significant role that the spreading oil layers play in maintaining the hydraulic conductivity of the oil phase between the matrix and the fracture. This mainly takes place at low remaining oil saturations under the spreading condition where layer drainage, in the presence of stable and connected spreading oil layers, is the dominant displacement mechanism. In the case of high remaining oil saturations, it is observed that the oil movement is primarily governed by piston-like displacements as well as the ability of the gas phase to access the pore elements adjacent to the fracture. Under the nonspreading condition, oil cannot maintain its connectivity due to the absence of the spreading layers, leading to higher residual oil saturations in the matrix and lower ultimate oil recovery.
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