Article
Green & Sustainable Science & Technology
Yang Song, Min Chen, Jia Li, Linglei Zhang, Yun Deng, Jichang Chen
Summary: Selective withdrawal is an effective and promising method to mitigate thermal pollution and environmental problems in reservoirs and downstream rivers. However, the potential effects of selective withdrawal on harmful algal blooms in reservoirs are uncertain. This study developed a hydro-ecological model to investigate how different withdrawal scenarios affect algal growth and hydrodynamic environments in Zipingpu reservoir. The results showed that surface withdrawal could efficiently inhibit algal growth and decrease algal bloom concentration in the reservoir.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Engineering, Civil
Sadegh Vanda, Mohammad Reza Nikoo, Narges Taravatrooy, Ghazi Ali Al-Rawas, Seyed M. K. Sadr, Fayyaz A. A. Memon, Banafsheh Nematollahi
Summary: A novel risk-based multi-objective compromise methodology was proposed for selective withdrawal from a dam reservoir. It allowed for selective water withdrawal from multiple outlets at different depths to account for the reservoir's water quality and thermal stratification. The research findings revealed that applying the proposed methodology could provide adequate water quality corresponding to different demands during thermal stratification to prepare effective guidelines for optimal reservoir operation.
WATER RESOURCES MANAGEMENT
(2023)
Article
Environmental Sciences
J. Eli Asarian, Crystal Robinson, Laurel Genzoli
Summary: Low streamflows can increase vulnerability to warming, impacting coldwater fish. Water managers need tools to quantify these impacts and predict future water temperatures. Contrary to most statistical models' assumptions, many seasonally changing factors (e.g., water sources and solar radiation) cause relationships between flow and water temperature to vary throughout the year.
WATER RESOURCES RESEARCH
(2023)
Article
Management
Daniel De Wolf, Yves Smeers
Summary: The article presents a characterization of the Clarke subdifferential of the optimal value function of a linear program in terms of matrix coefficients. It generalizes the result of Freund (1985) to situations where derivatives may not be defined due to the presence of multiple primal or dual solutions.
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH
(2021)
Article
Energy & Fuels
Suzhen Feng, Hao Zheng, Yifan Qiao, Zetai Yang, Jinwen Wang, Shuangquan Liu
Summary: This study improves the traditional weekly hydropower scheduling method by integrating hourly power and capacity balances, leading to increased solution efficiency. The case studies reveal that the traditional method overestimates the benefits, indicating the necessity to include hourly power and capacity balances in long/mid-term hydropower scheduling.
Article
Economics
Pietro Tebaldi, Alexander Torgovitsky, Hanbin Yang
Summary: We propose a new nonparametric approach to analyze the demand for health insurance, allowing for endogenous prices and instrumental variables. The model avoids parametric assumptions and estimates bounds on the effects of changing premiums or subsidies on coverage choices, consumer surplus, and government spending. Our findings show that decreasing monthly premium subsidies by $10 would lead to a decline in subsidized adults with coverage by 1.8% to 6.7%. The reduction in consumer surplus would range from $62 to $74 million, while savings in subsidy outlays would range from $207 to $602 million. We also explore the impact of age-based subsidies and the removal of highly-subsidized plans.
Review
Agriculture, Dairy & Animal Science
Gene M. Pesti, Mingan Choct
Summary: Current methods for feed formulation focus on cost reduction rather than profit maximization. The development of profit maximizing models will center on the production functions of broilers and layers, optimizing the relationship between the value of products and feed costs.
Article
Environmental Sciences
Wei He, Haiyang Wang, Jian Zhang, Hui Xu, Yang Xiao
Summary: This paper investigates the diurnal variation characteristics of thermal structure in reservoir and the effects of selective withdrawal. It reveals that there are three main regions with significant diurnal temperature variation in the reservoir area, namely the surface layer, the 10-m water layer, and the 60-m water layer. The diurnal temperature variation remains unchanged at the surface layer from the upstream to the downstream channels of the reservoir, but increases at the 10-m depth layer and 60-m depth layer. Higher withdrawal elevation and internal weir schemes are suggested for mitigating hypoxia and nutrient enrichment.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Engineering, Civil
Jerome Molenat, Cecile Dages, Maroua Bouteffeha, Insaf Mekki
Summary: This study demonstrates the use of small reservoirs for estimating stream runoff, especially at short temporal resolutions. The main factors contributing to estimation uncertainty are reservoir water level measurements and percolation rates.
JOURNAL OF HYDROLOGY
(2021)
Article
Computer Science, Artificial Intelligence
Sapan Kumar Das
Summary: This article addresses a fully fuzzy triangular linear fractional programming problem with parameters and decision variables characterized by triangular fuzzy numbers. A new concept is proposed to reduce computational complexity without sacrificing effectiveness. Mathematical models are used to evaluate the legitimacy, usefulness, and applicability of the method, showing that the novel strategies are superior to current techniques.
COMPLEX & INTELLIGENT SYSTEMS
(2022)
Article
Engineering, Civil
Seung Ki Kim, Sung-Uk Choi
Summary: The study investigated the possibility of improving downstream fish habitats by using selective withdrawal operations, finding that the impacts of cold water releases from the dam can be significantly reduced through these operations.
JOURNAL OF HYDROLOGY
(2021)
Article
Environmental Studies
Jorge Andres Garcia, Angelos Alamanos
Summary: This work models three common agricultural problems using optimization techniques: a water-scarce area with overexploited surface and groundwater resources (Greece), an area facing water quality deterioration caused by agriculture (Canada), and an intensified animal farming area facing environmental degradation and increased greenhouse gases emissions (Ireland). Multiple goals are considered to optimize farmers' welfare and environmental sustainability. The proposed approaches provide useful insights for countries facing similar problems.
Article
Engineering, Multidisciplinary
Kamel A. Almohseen
Summary: This article discusses the difficulties of adding if-condition to traditional linear programming models and proposes the use of mixed integer linear programming to address this issue, while also outlining the two prerequisites needed to minimize spillage.
JOURNAL OF ENGINEERING RESEARCH
(2021)
Article
Environmental Sciences
Meng Ao, Xiaotian Wang, Ying Sun, Fang Wang, Huanan Zhang, Lianhuan Wei, Shanjun Liu, Dong Yang
Summary: Southern California, USA, experiences surface deformation due to crustal movement and various human activities like groundwater extraction and oil exploitation. This study uses multi-path SAR data to investigate and monitor surface deformation, applying a unified simultaneous least squares approach to remove deformation discrepancies between adjacent SAR image paths. With the InSAR technique, multiple deformation patterns related to structural faults, groundwater withdrawal, and oil exploitation are observed. The results are validated using GPS monitoring data, and the correlations between land deformation and groundwater withdrawal, faults, and precipitation are extensively analyzed, providing insights into the magnitude and characteristics of ground deformation in Southern California.
Article
Computer Science, Hardware & Architecture
Roman Debski, Rafal Drezewski
Summary: This study presents a new dynamic programming algorithm for real-time simultaneous segmentation, compression, and smoothing of data streams. The algorithm is proven to be effective and energy efficient in the context of streaming sensor data. The key elements of the algorithm, including the adaptive search space, objective function, and search space reduction technique, are discussed in detail. Numerical results demonstrate that the new algorithm outperforms reference algorithms in terms of approximation accuracy and compression ratio. The proposed algorithm can be applied to various domains, such as IoT devices, sensor networks, and autonomous vehicles.
Article
Environmental Sciences
J. Brahney, M. L. Bothwell, L. Capito, C. A. Gray, S. E. Null, B. Menounos, P. J. Curtis
Summary: Glaciers provide essential runoff for mountain streams, maintaining unique habitats and supporting diverse flora and fauna. As glaciers retreat, significant changes are observed in mountain ecosystems, impacting stream conditions and diatom communities.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Review
Environmental Sciences
Sarah E. Null, Ali Farshid, Gregory Goodrum, Curtis A. Gray, Sapana Lohani, Christina N. Morrisett, Liana Prudencio, Ratha Sor
Summary: The paper discusses the impacts of hydropower development on the environment in the Mekong riparian countries, especially in the 3S Basin, and the potential ecological and biodiversity losses from future dam construction. It highlights the importance of considering environmental objectives in tradeoff analyses to quantify the environmental costs of dam development and maintain the biodiversity of the Lower Mekong Basin's extraordinary freshwater fishery.
Article
Forestry
Curtis A. Gray, Chelsea Toone, Michael J. Jenkins, Sarah E. Null, Larissa L. Yocom
Summary: Mountain pine beetle outbreaks cause significant changes in fine surface fuels and foliar fuel moisture in whitebark pine trees, leading to differences in fuel depth and moisture content among trees with different crown conditions. The hazard of fuel availability varies across the landscape following beetle attacks.
FOREST ECOLOGY AND MANAGEMENT
(2021)
Article
Environmental Sciences
Savoeurn Soum, Peng Bun Ngor, Thomas E. Dilts, Sapana Lohani, Suzanne Kelson, Sarah E. Null, Flavia Tromboni, Zeb S. Hogan, Bunyeth Chan, Sudeep Chandra
Summary: The study investigated the long-term dynamics of water quality in the Tonle Sap lake-river floodplain ecosystem over 22 years, revealing variations in most water quality parameters, with pH and nitrate remaining constant. Changes in the chemical nutrient ratio indicated that nitrogen may be the primary limiting nutrient. Water quality was found to be strongly influenced by watershed development, climate, and changes in water level.
Article
Computer Science, Interdisciplinary Applications
Adel M. Abdallah, David E. Rheinheimer, David E. Rosenberg, Stephen Knox, Julien J. Harou
Summary: This paper discusses the use of multiple tools by water systems modelers for data storage, querying, visualization, and sharing. By connecting these tools in an open-source software ecosystem, it becomes possible to compare models from different regions and publish them for discovery and use.
ENVIRONMENTAL MODELLING & SOFTWARE
(2022)
Article
Environmental Sciences
Darren L. Ficklin, Sarah E. Null, John T. Abatzoglou, Kimberly A. Novick, Daniel T. Myers
Summary: Global warming intensifies the hydrological cycle, resulting in more extreme precipitation events and longer dry spells. Previous studies have focused on precipitation without considering changes in evaporative demand and plant responses. Using state-of-the-art climate models, we examine projected changes in hydrological intensification and its impact on water resources management. Our findings show that surplus events will become larger and more frequent, with the greatest changes expected in the northern latitudes. These extreme events will stress existing water management infrastructure in major river basins, particularly those with large reservoir capacity.
Article
Environmental Sciences
Mahesh L. Maskey, Gustavo Facincani Dourado, Anna M. Rallings, David E. Rheinheimer, Josue Medellin-Azuara, Joshua H. Viers
Summary: Freshwater aquatic ecosystems are highly sensitive to flow regime alteration caused by anthropogenic activities, and this study evaluated the potential changes to the flow regime of the major tributaries of the San Joaquin River Basin in California due to climate change and reservoir operations. The study found that most indicators of streamflow dynamics had pronounced departures from baseline conditions under anticipated future climate conditions given existing reservoir operations. Additionally, the degree of flow regime alteration due to reservoir operations was found to be higher than that of climate change.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2022)
Review
Environmental Sciences
Masoud Parsinejad, David E. Rosenberg, Yusuf Alizade Govarchin Ghale, Bahram Khazaei, Sarah E. Null, Omid Raja, Ammar Safaie, Somayeh Sima, Armin Sorooshian, Wayne A. Wurtsbaugh
Summary: Public concern about environmental issues is high, but restoring ecosystem requires integration across multiple fields. A study on the desiccation and recovery of Lake Urmia in Iran found that agricultural expansion, dam construction, and mismanagement had a greater impact on the lake than temperature changes. Steps such as improving livelihoods for farmers, managing lake levels, and engaging the public are crucial for lake recovery.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Ann D. Willis, David E. Rheinheimer, Sarah M. Yarnell, Gustavo Facincani Dourado, Anna M. Rallings, Joshua H. Viers
Summary: This study models alternative environmental flow strategies in the major tributaries to the San Joaquin River in California. Results show that these strategies have different impacts on downstream flow releases and hydropower production in different sub-basins. The functional flow and 40% full natural flow strategies increase water released to the river relative to baseline, but in different ways and with varying ecological benefits.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2022)
Article
Engineering, Environmental
Gregory C. Goodrum, Sarah E. Null
Summary: This study estimated aquatic habitat suitability for Bonneville Cutthroat Trout and Bluehead Sucker in Utah using publicly available geospatial datasets. The researchers evaluated 15 habitat suitability models and found that simple models outperformed those that used only streamflow. These models are useful for conservation planning and water resources decision-making.
JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION
(2023)
Article
Green & Sustainable Science & Technology
Kimsan Chann, Ty Sok, Romduol Khoeun, Vuthy Men, Supattra Visessri, Chantha Oeurng, Ratha Sor, Sarah E. Null
Summary: This study characterized drought events in the Sesan and Srepok Basins and found frequent, severe, and prolonged drought occurrences. The results can be used as a baseline for assessing potential future droughts and designing drought management plans.
Article
Multidisciplinary Sciences
Ratha Sor, Peng Bun Ngor, Sovan Lek, Kimsan Chann, Romduol Khoeun, Sudeep Chandra, Zeb S. Hogan, E. E. Sarah
Summary: Hydropower dams, although a source of renewable energy, have negative impacts on freshwater ecosystems, biodiversity, and food security. This study analyzes the effects of dam development on fish biodiversity in the Sekong, Sesan, and Srepok Basins from 2007 to 2014. It shows that dam construction reduces fish biodiversity in the Sesan and Srepok Basins, while the Sekong Basin experiences an increase. The study emphasizes the importance of preserving free-flowing rivers, like the Sekong, Cambodian Mekong, and Tonle Sap Rivers, for migratory and threatened fish species.
SCIENTIFIC REPORTS
(2023)
Article
Ecology
Peng Bun Ngor, Sophorn Uy, Ratha Sor, Bunyeth Chan, Joseph Holway, Sarah E. Null, Nam So, Gael Grenouillet, Sudeep Chandra, Zeb S. Hogan, Sovan Lek
Summary: Predictive models are widely used to investigate relationships between fish diversity, abundance, and the environment. In this study, six single statistical models were evaluated for predicting fish richness and abundance in the Mekong River Basin. The Random Forest model consistently out-performed other models, while the Generalized Linear Model performed the worst. Water level, distance from the sea, and alkalinity were identified as important predictors of variation in both richness and abundance.
FRONTIERS IN ECOLOGY AND EVOLUTION
(2023)
Article
Environmental Sciences
Christina N. Morrisett, Robert W. Van Kirk, Sarah E. Null
Summary: Reservoirs in the Henrys Fork Snake River in Idaho, USA, are managed to meet irrigation demand and maintain aquatic habitat. A flow target in a management reach has been used since 1978 and has undergone four assignments. Recently, changes to irrigation-season management prompted investigation into the flow target assignment. A streamflow-habitat model was created to assess habitat availability under different management regimes. The study found that adjustments to the flow target and considering local irrigation diversions can contribute to more consistent fish habitat.
RIVER RESEARCH AND APPLICATIONS
(2023)
Review
Green & Sustainable Science & Technology
David E. Rheinheimer, Brian Tarroja, Anna M. Rallings, Ann D. Willis, Joshua H. Viers
Summary: Reservoir-based hydropower systems are being transformed under policy initiatives driven by increasing water and energy demand, the desire to reduce environmental impacts, and interacting effects of climate change. Different approaches and assumptions in hydropower representation in water and energy systems have been reviewed, with a focus on applications in California. These divergent modeling approaches may result in inadequate representations of each respective sector and vastly different planning outcomes, and better integration of water and energy models is needed.
ENVIRONMENTAL RESEARCH: INFRASTRUCTURE AND SUSTAINABILITY
(2023)
