1,496 research outputs found

    A review on integration of artificial intelligence into water quality modelling

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    2005-2006 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

    A review on the integration of artificial intelligence into coastal modeling

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    Author name used in this publication: Kwokwing Chau2005-2006 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe

    Temporal variation in riverine organic carbon concentrations and fluxes in two contrasting estuary systems: Geum and Seomjin, South Korea

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    In this study, surface water samples were collected at sites located in the lowest reaches of closed (Geum) (i.e. with an estuary dam at the river mouth) and open (Seomjin) estuary systems between May 2016 and May 2018. We analyzed concentrations and stable isotopes of particulate organic carbon (POC) and dissolved organic carbon (DOC) to assess OC sources, to estimate fluxes of riverine OC, and to assess some of the factors driving OC exports in these two contrasting Korean estuary systems. Our geochemical results suggest that the contribution of the phytoplankton-derived POC to the total POC pool was larger in the Geum River than in the Seomjin River. Notably, a heavy riverine algae bloom occurred in the Geum River in August 2016, resulting in a high carbon isotopic composition (-19.4%) together with low POC/PN ratio (˂ 10) and POC/Chl-a ratio (˂ 100). In contrast, potential DOC sources in both the Geum River and the Seomjin River were a mixture of C3-derived forest soils and cropland organic matter. During the study period, the catchment area-normalized fluxes of POC and DOC were 0.40x10(-3) tC/km(2)/yr and 6.5x10(-2) tC/km(2)/yr in the Geum River and 5.2x10(-4) tC/km(2)/yr and 8.6x10(-4) tC/km(2)/yr in the Seomjin River, respectively. It appears that the POC flux was more weakly associated with the water discharge in the Geum River than in the Seomjin River, but the DOC fluxes were in general controlled by the water discharges in both rivers. Accordingly, the estuary dam of the Geum River might be one of the most strongly influencing factors on seasonal patterns in POC fluxes into the adjacent coastal seas, strongly modifying water residence times and thus biogeochemical processes.We would like to thank Dokyun Kim, Ji Hwan Hwang, Jong-Ku Gal, Dong-Hun Lee, Dahae Kim, and Solbin Kim for their assistance during fieldwork. This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Ministry of Science and ICT (MSIT) -South Korea [NRF-2016R1A2B3015388, KOPRI-PN19100]

    Model Eutrofikasi 2-Dimensi Berlapis Untuk Optimalisasi Lokasi Zona Budidaya Ikan Karamba Jaring Apung (KJA) Di Waduk Jatiluhur

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    The development of floating net aquaculture in Jatiluhur reservoir that reach up 21000 to 26 717 plot have been resulted in eutrophication that interfere of water treatmen raw water, tourism and water sports, so the reduction and redeployment zones floating net in the reservoir needs to be done. The purpose of this study looking for zone of floating net aquaculture in Jatiluhur reservoir. The zone is obtained from the optimization by maximizing the density plots floating net per segment in alternate zones with constraints status trophic allowed in the area of water treatment raw water in take, tourism and water sports in the downstream Jatiluhur reservoir through simulation of the chlorophyll-a concentration distribution from the 2 -dimensional layered eutrophication model for scenarios increase every 10 plots floating net in segments of alternative zones 1, 2, 3 in the downstream reservoirs and alternate zone 4 in the middle of the reservoir. The results of the eutrophication 2-dimensional layered model calculation been obtained segment length and width of 100 m. The optimization results show, the carriying capacity of water due to zoning plots Jatiluhur reservoir floating net per segment in the middle of the reservoir is greater than the downstream of the reservoir, and to get water Jatiluhur reservoir in oligotrophic status that does not interfere with other uses of the reservoir water, and to get water Jatiluhur reservoir in oligotrophic status that does not interfere with other uses of the reservoir water, the highest density of a plot floating net per segment is the alternative zone 4 of 10 plot floating net per segment or 4,420 plot floating net. For the the aquaculture fish in floating net in the area are currently recommended to be moved to alternative zone 4 which is located in the central part Jatiluhur reservoir

    Fuzzy Logic as a Tool for the Assessment of Water Quality for Reservoirs: A Regional Perspective (Lerma River Basin, Mexico)

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    The aim of this study is to propose a water quality index for reservoirs in a basin using fuzzy logic. Most of the water quality indices are designed for use in rivers and streams and based on expert opinion; however, when the water is dammed, the quality usually Is modified. Mexico is a country with many contrasts in quantity and quality of water. Management of water resources in the Lerma River is achieved with a system of artificial reservoirs where water is stored in order to meet human needs, such as public supply, industry, agriculture and recreation, among others. Monitoring of 11 reservoirs in the Río Lerma basin was performed to characterize the water quality. Using the water quality data, those indicators that do not represent redundancy were selected based on the concentration gradient that occurred in the different reservoirs. Thus, the proposed index uses eight indicators of water quality. The fuzzy inference system is composed by 633 rules with a score from 0 to 100 and seven verbal categories. The index was validated by comparison with other water quality index, and their use across the basin was tested by applying it in five additional water bodies

    Interactions between Aquatic Plants and Cyanobacterial Blooms in Freshwater Reservoir Ecosystems

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    Climate change and nutrient pollution are echoed by worldwide increasing trends in the frequency, duration, and toxicity of cyanobacterial (blue-green algal) blooms. Therefore, searching for the best options to mitigate blooms is relevant and timely. Aquatic vascular plants offer a promising solution through biological control. In this study, we use reservoirs regularly affected by intensive blooms (the Kyiv and Kaniv Reservoirs of the Dnipro River, Ukraine) to investigate whether macrophytes may inhibit or reduce the massive development of cyanobacteria. Special attention was paid to plants with floating leaves and free-floating plants since data on their effects on cyanobacteria are controversial. On the basis of field and satellite observations, the spatial distribution of cyanobacterial blooms and aquatic macrophyte patches was assessed. Multispectral images captured by satellites Sentinel-2a (S2A) and Sentinel-2b (S2B) were used. In addition, based on data from field observations, a comparative analysis of phytoplankton and physical and chemical parameters between areas of the reservoirs overgrown and not overgrown by macrophytes was carried out. The obtained results indicate that in macrophyte patches phytoplankton structure differed from that observed in open waters. However, in areas of reservoirs dominated by floating-leaf plants or free-floating plants, a significant decrease in phytoplanktic or cyanobacterial biomass was not observed. This is most likely due to the fact that these macrophytes did not reduce the concentration of biogenic substances to a level that would limit cyanobacterial growth. On the contrary, intensive overgrowth of floating-leaf plants (in particular, Trapa natans) along the river sections of the reservoirs, as well as other factors, contributed to nitrogen and phosphorus enrichment. Therefore, in the face of relevant nutrient supply, these ecological groups of macrophytes (floating-leaf plants and free-floating plants) have not shown statistically significant effectiveness in controlling the process of cyanobacterial blooms in reservoir ecosystems

    A systematic review of application of multi-criteria decision analysis for aging-dam management

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    [EN] Decisions for aging-dam management requires a transparent process to prevent the dam failure, thus to avoid severe consequences in socio-economic and environmental terms. Multiple criteria analysis arose to model complex problems like this. This paper reviews specific problems, applications and Multi-Criteria Decision Making techniques for dam management. Multi-Attribute Decision Making techniques had a major presence under the single approach, specially the Analytic Hierarchy Process, and its combination with Technique for Order of Preference by Similarity to Ideal Solution was prominent under the hybrid approach; while a high variety of complementary techniques was identified. A growing hybridization and fuzzification are the two most relevant trends observed. The integration of stakeholders within the decision making process and the inclusion of trade-offs and interactions between components within the evaluation model must receive a deeper exploration. Despite the progressive consolidation of Multi-Criteria Decision Making in dam management, further research is required to differentiate between rational and intuitive decision processes. Additionally, the need to address benefits, opportunities, costs and risks related to repair, upgrading or removal measures in aging dams suggests the Analytic Network Process, not yet explored under this approach, as an interesting path worth investigating.This research was funded by the Spanish Ministry of Economy and Competitiveness along with FEDER funding (Projects BIA201456574-R and ECO2015-66673-R).Zamarrón-Mieza, I.; Yepes, V.; Moreno-Jiménez, JM. (2017). A systematic review of application of multi-criteria decision analysis for aging-dam management. Journal of Cleaner Production. 147:217-230. https://doi.org/10.1016/j.jclepro.2017.01.092S21723014

    A hydroinformatic tool for sustainable estuarine management

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    Book edited by Harry Edmar Schulz, André Luiz Andrade Simões and Raquel Jahara Lobosco• Short characterization of estuarine systems and the Mondego estuary (Portugal); • Research methods: sampling program description and mathematical integrated modelling (hydroinformatic tool presentation) • Hydrodynamic estuarine modelling, including calibration and validation procedures; • New approach for tidal prism and flow estimation in estuaries, using mathematical modelling. • Estuarine dispersion conditions, including the assessment of saline wedge propagation into the Mondego estuary. • Influence of tides and freshwater discharges on residence time spatial distribution in the Mondego estuary

    River Basin Water Quality Management Models: A State-of-the-Art Review

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    With the increasing human activities within river basins, the problem of water quality management is becoming increasingly important. Quality management can be achieved through control/prevention measures that have various economic and water quality implications. To facilitate the analysis of available management options, decision models are needed which represent the many facets of the problem. Such models must be capable of adequately depicting the hydrological, chemical and biological processes occurring in the river; while incorporating social, economic and political considerations within the decision framework. Management analyses can be performed using simulation, optimization, or both, depending on the management goal and the size and type of the problem. The critical issues in a management model are the nonlinearities, uncertainties, multiple pollutant nature of waste discharges, multiple objectives, and the spatial and temporal distribution of management actions. Literature on various management models were reviewed under the headings of linear, nonlinear and dynamic programming approaches; their stochastic counterparts, and combined or miscellaneous approaches. Dynamic programming was found to be an attractive methodology which can exploit the sequential decision problem pertaining to river basin water quality problems (downstream control actions do not influence water quality upstream). DP handles discrete decision variables which represent discrete management alternatives, and it is generic in the sense that both linear and non-linear water quality models expressing the relation between emissions and ambient quality levels can be incorporated. An example problem is presented which demonstrates the application of a DP-based management model to formulate least-cost strategies for the Nitra River basin in Slovakia. However, it is hardly possible for a single model to represent all the aspects of a complex decision problem. Different types of management models (e.g. deterministic vs stochastic models) have different capabilities and limitations. The only way to compensate for the deficiencies is to perform the analysis in a sensitivity style. The necessity for sensitivity analyses is further implied due to the fact that water quality problems are rather loosely formulated with respect to the quality and economic goals
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