127 research outputs found

    Evidence from field measurements and satellite imaging of impact of Earth rotation on Lake Iseo chemistry

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    During an initial field survey in 2012, we observed an unexpected asymmetry of dissolved oxygen distribution between the western and eastern side in northern Lake Iseo. Motivated by this apparent anomaly, we conducted a detailed field investigation, and we used a physical model of the northern part of the lake to understand the in- fluences that might affect the distribution of material in the northern section of the lake. These investigations sug- gested that the Earth's rotation has significant influence on the inflow of the lake's two main tributaries. In order to further crosscheck the validity of these results, we conducted a careful analysis at a synoptic scale using images acquired during thermally unstratified periods by Landsat-8 and Sentinel-2 satellites. We retrieved and post- processed a large set of images, providing conclusive evidence of the role exerted by the Earth's rotation on pol- lutant transport in Lake Iseo and of the greater environmental vulnerability of the north-west shore of this lake, where important settlements are located. Our study confirms the necessity for three-dimensional hydrodynamic models including Coriolis effect in order to effectively predict local impacts of inflows on nearshore water quality of medium-sized elongated lakes of similar scale to Lake Iseo

    Long-term phenomenological model of phosphorus and oxygen for stratified lakes

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    A budget model is developed to predict the long-term response of a lake to changes in its phosphorus loading. This model computes total phosphorus and hypolimnetic oxygen concentrations, taking sediment-water interactions into account.The lake is treated as two segments: the water and a surface sediment layer. A total phosphorus budget for the water accounts for inputs due to external loading and recycle from the sediments. It reflects losses due to flushing and settling. The sediment layer gains total phosphorus by settling and loses total phosphorus by recycle and burial. The recycle from the sediments to the water is dependent on the levels of sediment total phosphorus and hypolimnetic oxygen. Hypolimnetic oxygen concentration is estimated with a semi-empirical model.The model is applied to Shagawa Lake. An analysis is performed to demonstrate how its predictions replicate in-lake changes not possible with simpler phosphorus budget models.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29315/1/0000380.pd

    Calibration and application of a sediment accumulation rate model – a case study

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    A mechanistic mass balance model for sediment accumulation rate (SAR) that accommodates the dry density and burial velocity of solids and the depth dependency of porosity was tested and applied to Onondaga Lake, New York, for a 130-year period. The modeling for this case study is supported by a rich history of multiple anthropogenic drivers and coupled date horizons from the paleolimnological record, characterization of physical attributes of the sediments, and long-term monitoring of the water column and lake inputs. The consistency of predictions of SAR and measurements of downward flux of suspended particulate material (DFSPM) from a long-term sediment trap program was also evaluated. The model was demonstrated to perform well in simulating the lake’s history of SAR, which was supported by 10 different depth–date horizons. This history for 100 years was regulated by the production of soda-ash at an adjoining industry, which enhanced autochthonous formation and deposition of calcium carbonate (CaCO3), proportional to the level of production of this chemical. The SAR was extraordinarily high (~5 kg m-2 yr-1) during the 40 years of peak soda-ash production. An abrupt, more than 2-fold decrease in SAR occurred when the industry closed. The contemporary SAR remains relatively high as a result of multiple drivers but is serving to enhance burial of contaminants, including mercury, as part of an ongoing rehabilitation program. A high level of consistency (within 30%) between the contemporary SAR and an annual estimate of DFSPM was documented. The utility of the model was demonstrated through applications that depict the amount of deposits contributed by the industry, the effect of compaction on burial velocity, the dilution effect of the high SAR values on the paleolimnological record, and the resolution of sediment diagenesis kinetics

    Applied Numerical Methods Whit Matlab For Engineers And Scientists

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    xvi, 384 hal.; ill.; 25c

    Metode Numerik Jilid 1

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    xiv , 406 hlm ; 24 c

    Applied numerical methods : with MATLAfor engineers and scientists

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    xvi, 384 p : ill.; 25 cm

    Surface water-quality modeling

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    xix, 844 p. : ill. ; 25 cm

    SURFACE WATER QUALITY MODELING

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    XIX+844HLM;22,5C

    Surface Water-Quality Modeling

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    X, 844 tr.; 22 cm

    Applied numerical methods with Matlab, for engineers and scientists. Second edition

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    New Yorkxx, 588 p.: bibl., index; 24 c
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