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The aim of this study is to develop a two-dimensional hydrodynamic tidal model for the Persian Gulf (PG2017) using 2D-MIKE21 software. The advantages of present study is accounting for the spatial variation of bed friction coefficient besides a precise bathymetry together with a 23-year of combined records of satellite altimetry data. We found that the bed friction coefficient has a significant effect on sea level changes in the region under our modeling consideration. Since the tidal behavior in the northern part of the Qeshm Island is significantly different from the other parts of the Persian Gulf, to present a more accurate hydrodynamic tidal model, the Gulf is divided into two regions where the bed friction coefficient is modeled separately for each region. The root mean square value of the differences between the amplitude of dominant constituents; M2, S2, K1, and O1 derived from the PG2017 model and that of 98 altimetry and coastal tide gauge stations are respectively equal to 1.6, 1.9, 2.8, and 1.3?cm. Moreover, comparing the PG2017 model efficiency with the FES2014, OSU12, EOT11a, DTU10, and Admiralty models shows that the PG2017 model has an improvement of 22.1%, 47.2%, 43.2%, 44.2%, and 57.6% in terms of relative error, respectively. 相似文献
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Mohammad M. Sohrabi Rohan Benjankar Daniele Tonina Seth J. Wenger Daniel J. Isaak 《水文研究》2017,31(9):1719-1733
Stream water temperature plays a significant role in aquatic ecosystems where it controls many important biological and physical processes. Reliable estimates of water temperature at the daily time step are critical in managing water resources. We developed a parsimonious piecewise Bayesian model for estimating daily stream water temperatures that account for temporal autocorrelation and both linear and nonlinear relationships with air temperature and discharge. The model was tested at 8 climatically different basins of the USA and at 34 sites within the mountainous Boise River Basin (Idaho, USA). The results show that the proposed model is robust with an average root mean square error of 1.25 °C and Nash–Sutcliffe coefficient of 0.92 over a 2‐year period. Our approach can be used to predict historic daily stream water temperatures in any location using observed daily stream temperature and regional air temperature data. 相似文献
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Assessment of climate variations in temperature and precipitation extreme events over Iran 总被引：1，自引：0，他引：1
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Geotechnical and Geological Engineering - An analytical model defining soil-foundation probability of failure with respect to total system stability was developed in the present study. Soil... 相似文献
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Natural Hazards - Extreme weather events such as heat waves and cold spells affect people’s lives. This study develops a probabilistic framework to evaluate heat waves and cold spells. As... 相似文献
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Natural Resources Research - The northwest of Iran is considered as a promising geothermal zone owing to its geographical properties, tectonic features, and thermal activities, particularly in... 相似文献
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In the present research, effect of silica fume as an additive and oil polluted sands as aggregates on compressive strength of concrete were investigated experimentally. The amount of oil in the designed mixtures was assumed to be constant and equal to 2% of the sand weight. Silica fume accounting for 10%, 15% and 20% of the weight is added to the designed mixture. After preparation and curing, concrete specimens were placed into the three different conditions: fresh, brackish and saltwater environments (submerged in fresh water, alternation of exposed in air & submerged in sea water and submerged in sea water). The result of compressive strength tests shows that the compressive strength of the specimens consisting of silica fume increases significantly in comparison with the control specimens in all three environments. The compressive strength of the concrete with 15% silica fume content was about 30% to 50% higher than that of control specimens in all tested environments under the condition of using polluted aggregates in the designed mixture. 相似文献
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Thuro Arnold Nils Baumann Sina Brockmann Udo Zimmermann Stephan Weiß 《Geochimica et cosmochimica acta》2011,75(8):2200-3065
The subsurface acid mine drainage (AMD) environment of an abandoned underground uranium mine in Königstein/Saxony/Germany, currently in the process of remediation, is characterized by low pH, high sulfate concentrations and elevated concentrations of heavy metals, in particular uranium. Acid streamers thrive in the mine drainage channels and are heavily coated with iron precipitates. These precipitates are biologically mediated iron precipitates and related to the presence of Fe-oxidizing microorganisms forming copious biofilms in and on the Fe-precipitates. Similar biomineralisations were also observed in stalactite-like dripstones, called snottites, growing on the gallery ceilings.The uranium speciation in these solutions of underground AMD waters flowing in mine galleries as well as dripping from the ceiling and forming stalactite-like dripstones were studied by time resolved laser-induced fluorescence spectroscopy (TRLFS). The fluorescence lifetime of uranium species in both AMD water environments were best described with a mono-exponential decay, indicating the presence of one major species. The detected positions of the emission bands and by comparing it in a fingerprinting procedure with spectra obtained for acid sulfate reference solutions, in particular Fe(III) - SO42− - UO22+ reference solutions, indicated that the uranium speciation in the AMD environment of Königstein is dominated in the pH range of 2.5-3.0 by the highly mobile aquatic uranium sulfate species UO2SO4(aq) and formation of uranium precipitates is rather unlikely as is retardation by sorption processes. The presence of iron in the AMD reduces the fluorescence lifetime of the UO2SO4(aq) species from 4.3 μs, found in iron-free uranium sulfate reference solutions, to 0.7 μs observed in both AMD waters of Königstein and also in the iron containing uranium sulfate reference solutions.Colloids were not observed in both drainage water and dripping snottite water as photon correlation spectroscopy analyses and centrifugation experiments at different centrifugal accelerations between 500g and 46000g revealed. Thus transport and uranium speciation at the investigated AMD sites is neither influenced by U(IV) or U(VI) eigencolloids nor by uranium adsorbed on colloidal particles.This study shows that TRLFS is a suitable spectroscopic technique to identify the uranium speciation in bulk solutions of AMD environments. 相似文献