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Simulation of the Fate of Faecal Bacteria in Estuarine and Coastal Waters Based on A Fractionated Sediment Transport Model 被引量:1
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作者 YANG Chen LIU Ying 《China Ocean Engineering》 SCIE EI CSCD 2017年第4期389-395,共7页
A two-dimensional depth-integrated numerical model is refined in this paper to simulate the hydrodynamics, graded sediment transport process and the fate of faecal bacteria in estuarine and coastal waters. The sedimen... A two-dimensional depth-integrated numerical model is refined in this paper to simulate the hydrodynamics, graded sediment transport process and the fate of faecal bacteria in estuarine and coastal waters. The sediment mixture is divided into several fractions according to the grain size. A bed evolution model is adopted to simulate the processes of the bed elevation change and sediment grain size sorting. The faecal bacteria transport equation includes enhanced source and sink terms to represent bacterial kinetic transformation and disappearance or reappearance due to sediment deposition or re-suspension. A novel partition ratio and dynamic decay rates of faecal bacteria are adopted in the numerical model. The model has been applied to the turbid water environment in the Bristol Channel and Severn estuary, UK. The predictions by the present model are compared with field data and those by non-fractionated model. 展开更多
关键词 bed evolution decay rate esmarine and coastal water faecal bacteria fractionated model sediment Wansport
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Evaluating the Amount of Erodability and Sedimentation by Comparing Sediment Weight Model and PSIAC Experimental Model (Case Study: Lali Water Catchment, Khuzestan, Iran) 被引量:2
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作者 Abdolreza Alijani Nader Kohansal Ghadimvand +2 位作者 Mohsen Aleali Mohammad Reza Espahbod Ali Meysami 《Open Journal of Geology》 2016年第8期692-702,共11页
The upstream water catchments are the main source providing sediments in rivers and sedimentary basins. The balance between the erosion phenomenon and the amount of sediment entering into the basin relies on the geome... The upstream water catchments are the main source providing sediments in rivers and sedimentary basins. The balance between the erosion phenomenon and the amount of sediment entering into the basin relies on the geometrical specifications and the morphology of the river along the water catchment direction and the amount and type of the sediments. The sedimentary feed of rivers and basins are changed for the sake of natural factors or human disturbances. The river and basin react against this change in that their shape, morphology, plan and profile get changed due to the increase or decrease of the input sediment into the basin. It is essential to know the sediment amount produced by erodability and sedimentation of upstream basins and effects of projects and also to evaluate the amount of sedimentary load in base studies, civil projects, optimizing rivers and dam construction studies specially calculating the amount of sediment amount entering into the dams’ reservoirs in order to take engineering decisions and related alternatives. Sediment Weight Model and PSIAC Experimental Model are recognized as two common methods calculating the amount of the produced sediment caused by erosion applied in this research. Holistically, these methods have been used and compared. Although the results are almost close to one another, more sediment load has been produced in PSIAC method. As more affective parameters are used to cause erosion and produce sediment in PSIAC experimental model, it is recommended to refer to the results of this method because they are closer to reality. 展开更多
关键词 Erodability sedimentATION water Catchment sedimentary Basin The sediment Weight model PSIAC Experimental model
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THE STUDY ON THREE-DIMENSIONAL MATHEMATICAL MODEL OF RIVER BED EROSION FOR WATER-SEDIMENT TWO-PHASE FLOW 被引量:1
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作者 方红卫 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 1996年第1期85-91,共7页
Based on the tensor analysis of water-sediment two-phase how, the basic model equations for clear water flow and sediment-laden flow are deduced in the general curve coordinates for natural water variable-density turb... Based on the tensor analysis of water-sediment two-phase how, the basic model equations for clear water flow and sediment-laden flow are deduced in the general curve coordinates for natural water variable-density turbulent how. Furthermore, corresponding boundary conditions are also presented in connection with the composition and movement of non-uniform bed material. The theoretical results are applied to the calculation of the float open caisson in the construction period and good results are obtained. 展开更多
关键词 flow mathematical model sediment-laden flow mathematical model water-sediment two-phase flow float open caisson
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Effects of gravel on the water absorption characteristics and hydraulic parameters of stony soil
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作者 MA Yan WANG Youqi +2 位作者 MA Chengfeng YUAN Cheng BAI Yiru 《Journal of Arid Land》 SCIE CSCD 2024年第7期895-909,共15页
The eastern foothills of the Helan Mountains in China are a typical mountainous region of soil and gravel,where gravel could affect the water movement process in the soil.This study focused on the effects of different... The eastern foothills of the Helan Mountains in China are a typical mountainous region of soil and gravel,where gravel could affect the water movement process in the soil.This study focused on the effects of different gravel contents on the water absorption characteristics and hydraulic parameters of stony soil.The stony soil samples were collected from the eastern foothills of the Helan Mountains in April 2023 and used as the experimental materials to conduct a one-dimensional horizontal soil column absorption experiment.Six experimental groups with gravel contents of 0%,10%,20%,30%,40%,and 50%were established to determine the saturated hydraulic conductivity(K_(s)),saturated water content(θ_(s)),initial water content(θ_(i)),and retention water content(θ_(r)),and explore the changes in the wetting front depth and cumulative absorption volume during the absorption experiment.The Philip model was used to fit the soil absorption process and determine the soil water absorption rate.Then the length of the characteristic wetting front depth,shape coefficient,empirical parameter,inverse intake suction and soil water suction were derived from the van Genuchten model.Finally,the hydraulic parameters mentioned above were used to fit the soil water characteristic curves,unsaturated hydraulic conductivity(K_(θ))and specific water capacity(C(h)).The results showed that the wetting front depth and cumulative absorption volume of each treatment gradually decreased with increasing gravel content.Compared with control check treatment with gravel content of 0%,soil water absorption rates in the treatments with gravel contents of 10%,20%,30%,40%,and 50%decreased by 11.47%,17.97%,25.24%,29.83%,and 42.45%,respectively.As the gravel content increased,inverse intake suction gradually increased,and shape coefficient,K_(s),θ_(s),andθ_(r)gradually decreased.For the same soil water content,soil water suction and K_(θ)gradually decreased with increasing gravel content.At the same soil water suction,C(h)decreased with increasing gravel content,and the water use efficiency worsened.Overall,the water holding capacity,hydraulic conductivity,and water use efficiency of stony soil in the eastern foothills of the Helan Mountains decreased with increasing gravel content.This study could provide data support for improving soil water use efficiency in the eastern foothills of the Helan Mountains and other similar rocky mountainous areas. 展开更多
关键词 stony soil gravel content water absorption characteristics hydraulic parameters one-dimensional horizontal soil column absorption experiment van Genuchten model eastern foothills of Helan Mountains
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Dynamic simulation and modeling of PCP transport between sediment and water
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作者 Li Tie Ye Chang-ming Lei Zhi-fang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1998年第1期71-77,共7页
A model to calculate the concentration of organic pollutant in the water column is presented. The inflow, outflow, adsorption of pollutant to the suspended particles and settling of particles, diffusion across the s... A model to calculate the concentration of organic pollutant in the water column is presented. The inflow, outflow, adsorption of pollutant to the suspended particles and settling of particles, diffusion across the sediment water interface, and volatilization to the atmosphere were considered in this model. Dynamic simulation experiment of pentachlorophenol(PCP) has been made in the laboratory. The model parameters were also estimated with experimental data(diffusion mass transfer coefficient, 0.00112m/d; net settling velocity of particles, 0.323 m.d -1 ; volatilization rate constant, 1.94×10 -4 d -1 ). There are little differences between calculated values and measured values. Adsorption of pollutant to the particles and settling of particles are very important mechanisms for removal of organic pollutant from the water. The principles and methods of this model are also applicable to the prediction of the concentration of other trace elements and organic constituents in aquatic systems. 展开更多
关键词 dynamic simulation modelING suspended particles PCP transport sediment/water interface.
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Sediment transport following water transfer from Yangtze River to Taihu Basin 被引量:2
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作者 Zheng GONG Chang-kuan ZHANG +1 位作者 Cheng-biao ZUO Wei-deng WU 《Water Science and Engineering》 EI CAS 2011年第4期431-444,共14页
To meet the increasing :need of fresh water and to improve the water quality of Taihu Lake, water transfer from the Yangtze River was initiated in 2002. This study was performed to investigate the sediment distributi... To meet the increasing :need of fresh water and to improve the water quality of Taihu Lake, water transfer from the Yangtze River was initiated in 2002. This study was performed to investigate the sediment distribution along the river course following water transfer. A rainfall-runoff model was first built to calculate the runoff of the Taihu Basin in 2003. Then, the flow patterns of river networks were simulated using a one-dimensional river network hydrodynamic model. Based on the boundary conditions of the flow in tributaries of the Wangyu River and the water level in Taihu Lake, a one-dimensional hydrodynamic and sediment transport numerical model of the Wangyu River was built to analyze the influences of the inflow rate of the water transfer and the suspended sediment concentration (SSC) of inflow on the sediment transport. The results show that the water transfer inflow rate and SSC of inflow have significant effects on the sediment distribution. The higher the inflow rate or SSC of inflow is, the higher the SSC value is at certain cross-sections along the :river course of water transfer. Higher inflow rate and SSC of inflow contribute to higher sediment deposition per kilometer and sediment thickness. It is also concluded that a sharp decrease of the inflow velocity at the entrance of the Wangyu River on the river course of water transfer induces intense sedimentation at the cross-section near the Changshu hydro-junction. With an increasing distance from the Changshu hydro-junction, the sediment deposition and sedimentation thickness decrease gradually along the river course. 展开更多
关键词 Taihu Basin Taihu Lake river network water transfer rainfall-runoff model 1-D hydrodynamic numerical model cohesive sediment
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A Comparison of SWAT Model Calibration Techniques for Hydrological Modeling in the Ganga River Watershed 被引量:7
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作者 Nikita Shivhare Prabhat Kumar Singh Dikshir Shyam Bihari Dwivedi 《Engineering》 2018年第5期643-652,共10页
The Ganga River, the longest river in India, is stressed by extreme anthropogenic activity and climate change, particularly in the Varanasi region. Anticipated climate changes and an expanding populace are expected to... The Ganga River, the longest river in India, is stressed by extreme anthropogenic activity and climate change, particularly in the Varanasi region. Anticipated climate changes and an expanding populace are expected to further impede the efficient use of water. In this study, hydrological modeling was applied to Soil and Water Assessment Tool (SWAT) modeling in the Ganga catchment, over a region of 15 621.612 km2 in the southern part of Uttar Pradesh. The primary goals of this study are: ① To test the execution and applicability of the SWAT model in anticipating runoff and sediment yield; and ② to compare and determine the best calibration algorithm among three popular algorithms-sequential uncertainty fitting version 2 (SUFI-2), the generalized likelihood uncertainty estimation (GLUE), and par-allel solution (ParaSol). The input data used in the SWAT were the Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM), Landsat-8 satellite imagery, soil data, and daily meteorological data. The watershed of the study area was delineated into 46 sub-watersheds, and a land use/land cover (LULC) map and soil map were used to create hydrological response units (HRUs). Models utilizing SUFI- 2, GLUE, and ParaSol methods were constructed, and these algorithms were compared based on five cat-egories: their objective functions, the concepts used, their performances, the values of P-factors, and the values of R-factors. As a result, it was observed that SUFI-2 is a better performer than the other two algo-rithms for use in calibrating Indian watersheds, as this method requires fewer runs for a computational model and yields the best results among the three algorithms. ParaSol is the worst performer among the three algorithms. After calibrating using SUFI-2, five parameters including the effective channel hydraulic conductivity (CH_K2), the universal soil-loss equation (USLE) support parameter (USLE_P), Manning's n value for the main channel (CH_N2), the surface runoff lag time (SURLAG), and the available water capac-ity of the soil layer (SOL_AWC) were observed to be the most sensitive parameters for modeling the pre-sent watershed. It was also found that the maximum runoff occurred in sub-watershed number 40 (SW#40), while the maximum sediment yield was 50 t.a ^1 for SW#36, which comprised barren land. The average evapotranspiration for the basin was 411.55 mm.a ^1. The calibrated model can be utilized in future to facilitate investigation of the impacts of LULC, climate change, and soil erosion. 展开更多
关键词 Remote sensing Geographic information system Soil and water Assessment Tool Hydrological modeling SUFI-2 GLUE ParaSol sediment yield
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Nutrient exchange and release experiment and its simulation study in lake water-sediment interface 被引量:1
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作者 XUE Lian-qing HAO Zhen-chun 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2006年第3期591-595,共5页
The sediment distributed and insolated under lake was collected for experiments. The nutrient layer distribution conditions of sampled sediment and its physical and chemical characteristics were analyzed to simulate a... The sediment distributed and insolated under lake was collected for experiments. The nutrient layer distribution conditions of sampled sediment and its physical and chemical characteristics were analyzed to simulate and assess the influence degree to lake water quality. Based on the dynamic water exchanging experiments the nutrient release process in sediment and influence mechanism to substance exchanging on water-sediment interface was studied, and the correlation between the changing content of total phosphors and total nitrogen in sediment and covered water were analyzed for setting up a simulation model. At the same time the influence degree is explained in detail. The experimental results indicated that even if clean water without nutrient contents was used for water exchangement so as to decrease pollution or prevent eutrophication, however owing to the vertical nutrient distribution in lake sediment, it will lead to the increasing release amount greatly especially when the organic nutrient contained in sediment turns into inorganic status because of isolation. Besides the release process of total phosphate (TP) and total nitrogen (TN) were modeled and each nutrient's exchanging equation at interface caused by covered water nutrient concentration changing was set up. According to the simulating prediction, TP and TN content of cover water will also sustain a steady higher level in a long period. The nutrient release amount of sediment is not only affected by the covered water concentration but also connects with accumulative time. The experiments provide the fundamental theoretical and practical basis for taking ecological restoration project. And research is helpful to prevent or restore lake eutrophication. 展开更多
关键词 phosphate and nitrogen release water-sediment interface experiments simulation model
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Comparison of depth-averaged concentration and bed load flux sediment transport models of dam-break flow
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作者 Jia-heng Zhao Ilhan Ozgen +1 位作者 Dong-fang Liang Reinhard Hinkelmann 《Water Science and Engineering》 EI CAS CSCD 2017年第4期287-294,共8页
This paper presents numerical simulations of dam-break flow over a movable bed. Two different mathematical models were compared: a fully coupled formulation of shallow water equations with erosion and deposition terms... This paper presents numerical simulations of dam-break flow over a movable bed. Two different mathematical models were compared: a fully coupled formulation of shallow water equations with erosion and deposition terms(a depth-averaged concentration flux model), and shallow water equations with a fully coupled Exner equation(a bed load flux model). Both models were discretized using the cell-centered finite volume method, and a second-order Godunov-type scheme was used to solve the equations. The numerical flux was calculated using a Harten, Lax, and van Leer approximate Riemann solver with the contact wave restored(HLLC). A novel slope source term treatment that considers the density change was introduced to the depth-averaged concentration flux model to obtain higher-order accuracy. A source term that accounts for the sediment flux was added to the bed load flux model to reflect the influence of sediment movement on the momentum of the water. In a onedimensional test case, a sensitivity study on different model parameters was carried out. For the depth-averaged concentration flux model,Manning's coefficient and sediment porosity values showed an almost linear relationship with the bottom change, and for the bed load flux model, the sediment porosity was identified as the most sensitive parameter. The capabilities and limitations of both model concepts are demonstrated in a benchmark experimental test case dealing with dam-break flow over variable bed topography. 展开更多
关键词 Shallow water sediment transport Bed load FLUX model Depth-averaged CONCENTRATION FLUX model Dam break
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The Research and Application of BP Neural Networks in River-basin Water and Sediment
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作者 Xu Quan-xi Engineer, Hydrology Bureau,Changjiang Water Resources Commission, Wuhan 430010,China 《人民长江》 北大核心 2001年第S1期53-56,共4页
Based on the basic principles of BP artificial neural network model and the fundamental law of water and sediment yield in a river basin, a BP neural network model is developed by using observed data, with rainfall co... Based on the basic principles of BP artificial neural network model and the fundamental law of water and sediment yield in a river basin, a BP neural network model is developed by using observed data, with rainfall conditions serving as affecting factors. The model has satisfactory performance of learning and generalization and can be also used to assess the influence of human activities on water and sediment yield in a river basin. The model is applied to compute the runoff and sediment transmission at Xingshan, Bixi and Shunlixia stations. Comparison between the results from the model and the observed data shows that the model is basically reasonable and reliable. 展开更多
关键词 water and sediment yield in a RIVER-BASIN OBSERVED data water and sediment variation BP neural network model
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Water Flow and Sediment Flux Forecast in the ChókwèIrrigation Scheme, Mozambique
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作者 Lateiro Salvador De Sousa Raphael Muli Wambua +1 位作者 James Messo Raude Benedict Mwavu Mutua 《Journal of Water Resource and Protection》 2020年第12期1089-1122,共34页
This study sought to forecast water flow and sediment flux in the scheme as potential contributions for improved management in the Chókwè Irrigation Scheme (CIS). Fieldwork data was collected during dry (DS)... This study sought to forecast water flow and sediment flux in the scheme as potential contributions for improved management in the Chókwè Irrigation Scheme (CIS). Fieldwork data was collected during dry (DS) and wet (WS) seasons. Flow measurement was performed at 9 stations using a calibrated flow meter OTT C31. Water flow and sediment flux from 2004 to 2019 were used. Hydrodynamic forecast simulations were performed using Mann-Kendall test and ARIMA model for determination of temporal trends. Findings suggest higher values during DS for water discharge and sediment flux. Mann-Kendall test for sediment discharge trends was not significant at 95% significance level, except for the Offtake in WS. ARIMA test for the sediment discharges, at the Intake, for DS and WS, sediments were well described by the ARIMA model and gave a good result for the sediments. Good fit between the observed and the predicted ARIMA model was found. ARIMA model for sediment discharge at CIS based on AIC has a good fit for AR (p = 1), whereby, at the Intake the ARIMA p-value was 0.822 and 0.932, for WS and DS, respectively. Whilst in the Offtake, the ARIMA p-value was 0.877 and 0.893, respectively. These results can be used to improve the CIS management, both for water flow and sediment flux. 展开更多
关键词 water Flow sediment Flux Mann-Kendall Test ARIMA model Chókwè Irrigation Scheme
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Use of SWAT to Model Impact of Climate Change on Sediment Yield and Agricultural Productivity in Western Oregon, USA
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作者 G. W. Mueller-Warrant C. L. Phillips K. M. Trippe 《Open Journal of Modern Hydrology》 2019年第2期54-88,共35页
Climate change predictions for the Pacific Northwest region of the United States of America include increasing temperatures, intensification of winter precipitation, and a shift from mixed snow/rain to rain-dominant e... Climate change predictions for the Pacific Northwest region of the United States of America include increasing temperatures, intensification of winter precipitation, and a shift from mixed snow/rain to rain-dominant events, all of which may increase the risk of soil erosion and threaten agricultural and ecological productivity. Here we used the agricultural/environmental model SWAT with climate predictions from the Coupled Model Intercomparison Project 5 (CMIP5) “high CO2 emissions” scenario (RCP8.5) to study the impact of altered temperature and precipitation patterns on soil erosion and crop productivity in the Willamette River Basin of western Oregon. An ensemble of 10 climate models representing the full range in temperature and precipitation predictions of CIMP5 produced substantial increases in sediment yield, with differences between yearly averages for the final (2090-2099) and first (2010-2019) decades ranging from 3.9 to 15.2 MT&middot;ha-1 among models. Sediment yield in the worst case model (CanESM2) corresponded to loss of 1.5 - 2.7 mm&middot;soil&middot;y-1, equivalent to potentially stripping productive topsoil from the landscape in under two centuries. Most climate models predicted only small increases in precipitation (an average of 5.8% by the end of the 21st century) combined with large increases in temperature (an average of 0.05&deg;C&middot;y-1). We found a strong correlation between predicted temperature increases and sediment yield, with a regression model combining both temperature and precipitation effects describing 79% of the total variation in annual sediment yield. A critical component of response to increased temperature was reduced snowfall during high precipitation events in the wintertime. SWAT characterized years with less than basin-wide averages of 20 mm of precipitation falling as snow as likely to experience severe sediment loss for multiple crops/land uses. Mid-elevation sub-basins that are projected to shift from rain-snow transition to rain-dominant appear particularly vulnerable to sediment loss. Analyses of predicted crop yields indicated declining productivity for many commonly grown grass seed and cereal crops, along with increasing productivity for certain other crops. Adaptation by agriculture and forestry to warmer, more erosive conditions may include changes in selection of crop kinds and in production management practices. 展开更多
关键词 CLIMATE Change sediment Yield Soil water Assessment Tool SWAT Coupled model Intercomparison Project 5 CIMP5 Nash-Sutcliffe Efficiency NSE
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Sedimentary environment and petrological features of organic-rich fine sediments in shallow water overlapping deposits: A case study of Cambrian Yuertus Formation in northwestern Tarim Basin, NW China
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作者 JIN Zhimin TAN Xiucheng +7 位作者 TANG Hao SHEN Anjiang QIAO Zhanfeng ZHENG Jianfeng LI Fei ZHANG Shixuan CHEN Lei ZHOU Chenggang 《Petroleum Exploration and Development》 2020年第3期513-526,共14页
Taking the Cambrian Yuertus Formation outcrop profiles in the Aksu-Keping-Wushi areas of northwestern Tarim Basin as examples, the depositional environments of organic rich fine sediment were analyzed by examining the... Taking the Cambrian Yuertus Formation outcrop profiles in the Aksu-Keping-Wushi areas of northwestern Tarim Basin as examples, the depositional environments of organic rich fine sediment were analyzed by examining the outcrop profiles macroscopically and microscopically. The study reveals that:(1) The lower part of the Yuertus Formation consists of organic-rich fine sediment or thin rhythmic interbeds of organic-rich fine sediment and siliceous sediment, the formation transforms to terrigenous diamictic grain shoal and inverse grading carbonate rocks upward.(2) The thin limestone interbedded with dark shale rhythmically has inverse grading.(3) The thin-bedded siliceous rock has metasomatic residual granular texture, stromatolithic structure and cementation fabric in vugs.(4) There are iron crust layers at the top of the shallowing diamictic grain shoal, beneath which exposed karst signs, such as karrens, dissolved fissures, sack-like vugs, near surface karst(plastic) breccia, breccia inside the karst system and terrigenous clastic fillings, can be seen.(5) Both the outcrops and seismic profiles show that organic-rich fine sediments above the unconformities or exposed surfaces are characterized by overlapping. The organic-rich fine sediment of the Cambrian Yuertus Formation was deposited in the anoxic-suboxidized restricted gulf lagoon environment, and its formation was controlled by high paleoproductivity and poor oxygen exchange jointly, then a shallow-water overlapping sedimentary model has been established. The results will help enrich and improve the sedimentary theory of organic-rich fine sediments. 展开更多
关键词 fine-grained sediments source rock shallow water overlap exposed surface PALEOKARST sedimentary model Cambrian Yuertus Formation Tarim Basin
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Incorporating sorption/desorption of organic pollutants into river water quality model
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作者 LOUBao-feng ZHULi-zhong YANGKun 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第4期559-563,共5页
Preliminary research was conducted about how to incorporate sorption/desorption of organic pollutants with suspended solids and sediments into single-chemical and one-dimensional water quality model of Jinghang Canal.... Preliminary research was conducted about how to incorporate sorption/desorption of organic pollutants with suspended solids and sediments into single-chemical and one-dimensional water quality model of Jinghang Canal. Sedimentation-resuspension coefficient k 3 was deduced; characteristics of organic pollutants, concentrations and components of suspended solids/sediments and hydrological and hydraulic conditions were integrated into k 3 and further into river water quality model; impact of sorption/desorption of organic pollutants with suspended solids and sediments on prediction function of the model was discussed. Results demonstrated that this impact is pronounced for organic pollutants with relatively large K oc and K ow, especially when they are also conservative and f oc of river suspended solids/sediments is high, and that incorporation of sorption/ desorption of organic pollutants into river water quality model can improve its prediction accuracy. 展开更多
关键词 water quality model sorption/desorption sedimentation-resuspension coefficient
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Orthogonal experiment on reclaimed water treatment and economic optimization model in green building
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作者 何强 张成 +1 位作者 柴宏祥 樊明玉 《Journal of Central South University》 SCIE EI CAS 2009年第S1期322-328,共7页
The efficacy of superior drainage in green building treated by combinational technique of coagulation sedimentation and constructed wetland was launched. The results show that the regression equation relating to efflu... The efficacy of superior drainage in green building treated by combinational technique of coagulation sedimentation and constructed wetland was launched. The results show that the regression equation relating to effluent BOD5,cubage load (Nv),temperature (t) and addition dosage (ρ) is BOD5=2.05Nv-0.41t-0.82ρ+38.9. The orthogonal experiment results of constructed wetland post-treatment show that the regression equation relating to effluent BOD5,cubage load (NA),and temperature (t) is BOD5=1 190NA-0.32t+12.2. Based on the two orthogonal regression equations,combined of green building municipal gray reclaimed water quantity requirements in different seasons,a technology investment on economic optimization model of combinational technique was established. The results offer technological support for reclaimed water treatment,which regards superior drainage as the source and is purified by combinational technique of coagulation sedimentation and constructed wetland. According to the model,the reasonable scale of reclaimed water treatment systems can be determined,the treatment efficacy can be well predicted,and both the design and operating can be effectively guided. 展开更多
关键词 green BUILDING COAGULATION-sedimentATION CONSTRUCTED WETLANDS reclaimed water ECONOMIC optimization model
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On the Existence of Global Weak Solutions to 1D Sediment Transport Model
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作者 Roamba Brahima Zongo Yacouba +1 位作者 Yira Boulaye Zabsonré Jean de Dieu 《Journal of Applied Mathematics and Physics》 2021年第5期1065-1075,共11页
This paper is devoted to the study of the existence of weak solution in time with a periodic domain of sediment transport model. We consider a one-dimensional viscous sediment transport model which combines a viscous ... This paper is devoted to the study of the existence of weak solution in time with a periodic domain of sediment transport model. We consider a one-dimensional viscous sediment transport model which combines a viscous Shallow-Water system with a transport equation that describes the bottom evolution. The model studied does not take into account all the regularizing terms used by Roamba Brahima, Zongo Yacouba and Jean de Dieu Zabsonré (2017) and we use a better transport equation than that used by Zabsonré (2012). 展开更多
关键词 SHALLOW-water sediment Transport Viscous model Weak Solution
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三门峡水库控制运用方式的优化探讨
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作者 郭彦 侯素珍 +3 位作者 杨飞 王平 胡恬 赖瑞勋 《水电能源科学》 北大核心 2024年第7期202-206,39,共6页
三门峡水库“蓄清排浑”运用为多沙河流的治理提供了宝贵经验,随着来水来沙情况的变化及对水库功能需求和对水库泥沙冲淤规律认识的深化,该运行方式亦在实践中不断调整和完善。为此,针对不同的典型年份设定集中敞泄与分段敞泄的敞泄排... 三门峡水库“蓄清排浑”运用为多沙河流的治理提供了宝贵经验,随着来水来沙情况的变化及对水库功能需求和对水库泥沙冲淤规律认识的深化,该运行方式亦在实践中不断调整和完善。为此,针对不同的典型年份设定集中敞泄与分段敞泄的敞泄排沙方案,采用一维非恒定水沙数学模型,对选取的2018~2019年丰水少沙年和2014~2016年枯水少沙年设定12种控制运用方案进行模拟,比较各方案下库区冲淤变化的优劣,据此选取适合三门峡水库的控制运用方式。结果表明,2018~2019年分段敞泄方案的冲刷效果优于集中敞泄方案,即使在后汛期的控制水位抬高至310 m,也能达到较好的冲刷效果;2014~2016年分段敞泄方案虽优于集中敞泄方案,但其冲刷主要集中于2014年汛期,2015、2016年整体呈淤积状态,综合考虑建议枯水少沙年份水库采用“泥沙年际调节”运用模式。 展开更多
关键词 一维水沙模型 控制运用方式 敞泄排沙 冲淤变化 三门峡水库
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取水工程对松花江悦来河段影响研究
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作者 孙艳玲 黄海 +1 位作者 关见朝 杜江 《泥沙研究》 CAS CSCD 北大核心 2024年第2期56-63,共8页
为了研究引水工程的建设对松花江悦来河段水沙变化的影响,构建了松花江干流悦来河段的平面二维水沙数学模型,分析了引水工况对松花江悦来河段的流速、水位、分流比和冲淤分布的影响。研究结果表明:松北引渠引水入松花江致使入江处水位... 为了研究引水工程的建设对松花江悦来河段水沙变化的影响,构建了松花江干流悦来河段的平面二维水沙数学模型,分析了引水工况对松花江悦来河段的流速、水位、分流比和冲淤分布的影响。研究结果表明:松北引渠引水入松花江致使入江处水位抬升为0.03~0.04 m,由于松南引渠引水,致使取水口附近的主河道水位下降约0.03 m;在天然条件下,松南下口引渠位置分流量为78 m~3/s,分流比为8.8%,在取水方案下,松南上口引渠分流量为104 m~3/s,分流比为8.5%,松南下口引渠分流量为323 m~3/s,分流比为28.9%;在天然条件下,悦来河段主河道呈现冲刷状态,冲刷深度为1.0 m左右,双口引渠导致取水口附近的泥沙淤积较天然条件有所增加,其中松南引渠下口淤积更为显著,引渠口门处淤积厚度可达1.0 m以上。 展开更多
关键词 松花江 悦来河段 水沙数学模型 河道演变
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重金属污染水体背景下的底质反射率光谱特征及其对离水反射率贡献影响分析
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作者 梁业恒 邓孺孺 +4 位作者 梁钰婕 刘永明 吴仪 袁宇恒 艾先俊 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2024年第1期111-117,共7页
水体重金属遥感反演是水环境遥感领域中的难题,目前仍有相当多的基础性问题有待解决,而浅水区底质对离水反射率贡献规律是将来遥感反演模型精度其中一个重要影响因素,尤其在重金属污染这种特殊的背景下,揭示其贡献规律对提升水体重金属... 水体重金属遥感反演是水环境遥感领域中的难题,目前仍有相当多的基础性问题有待解决,而浅水区底质对离水反射率贡献规律是将来遥感反演模型精度其中一个重要影响因素,尤其在重金属污染这种特殊的背景下,揭示其贡献规律对提升水体重金属遥感模型精度有重要作用,测量结果对研究重金属尾矿底泥的反射率光谱特征以及区分常见水底底质有参考意义。首先利用光谱仪测量获得广东大宝山尾矿底质反射率,发现其在波长755、 1 280、 1 620和2 200 nm存在反射峰,有明显光谱特征,并与河床常见的粗沙、淤泥和石头三类底质反射率进行了对比分析,结果表明:一方面,粗沙和淤泥反射率呈一缓慢上升的曲线,与存在多个特征反射峰的矿区底泥有明显区别;另一方面,石头反射率则在波长范围550~650 nm出现一个宽而扁平的反射峰后随即在波长675 nm处出现波谷然后增大至波长750 nm后趋于平缓,其特征波长与矿区底泥均不一样。上述特征波长可作为重金属污染背景下底泥光谱的重要区分波段。测量水深为1 cm、 10 cm和深水区的离水反射率,结合水质遥感模型计算出1 cm水深情况下底质反射光、水体散射光,并将其对离水反射率贡献进行讨论。离水反射率测量结果表明,底质对浅水区影响极大,随着水深变浅,离水反射率总体不断被抬升。而水底反射光和水体散射光对离水反射率贡献规律则以波长515 nm为分界线,向短波方向以水体散射光贡献为主,向长波方向则以水底反射光为主,贡献量由底质反射能力和水体散射能力共同决定。对考虑了底质反射光后的遥感模型精度进行评价,模型计算得到波长范围350~950 nm内的离水反射率与野外测量值对比结果,二者具有显著的线性相关(R^(2)=0.964 2),相对误差在波长范围560~830 nm低于10%,甚者可低于5%,模型总体模拟精度较好,远比在不考虑底质影响时精度高,模型满足将来水中重金属遥感反演要求。研究结果对今后水体重金属遥感反演时处理底质影响提供了重要的参考数据和理论依据,有助推动该领域进一步发展。 展开更多
关键词 水体重金属遥感 重金属矿区 底质反射率 光谱特征分析 模型精度评价
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旋流排沙渠道中旋转水流的排沙效果研究
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作者 南军虎 马康宁 +3 位作者 汪超群 李伟 陶然 代江龙 《工程科学与技术》 EI CAS CSCD 北大核心 2024年第3期170-178,共9页
旋流排沙渠道是基于旋转水流强挟带能力的特点提出的一种渠道水沙分离新技术,为了明晰其水沙特性,在试验研究的基础上,采用Realizable k-ε模型、VOF法及离散相模型,对旋流排沙渠道内的水沙两相流特性进行了数值模拟,通过与模型试验成... 旋流排沙渠道是基于旋转水流强挟带能力的特点提出的一种渠道水沙分离新技术,为了明晰其水沙特性,在试验研究的基础上,采用Realizable k-ε模型、VOF法及离散相模型,对旋流排沙渠道内的水沙两相流特性进行了数值模拟,通过与模型试验成果的对比确定了不同粒径泥沙的球度,研究了持续来沙条件下旋流排沙渠道的排沙效果,分析了渠道和排沙洞内泥沙的分布规律。结果表明:不同粒径泥沙的球度介于0.2~1.0之间时,在渠道顶部局部来沙条件下旋流排沙渠道对粒径为(0.075,3.000]mm泥沙的计算截沙率与试验值吻合良好,二者的相对误差仅为3.5%,误差主要来源于(0.075,0.160]mm的极细颗粒泥沙;当上游渠道水流进口来沙质量流量为60 g/s时,渠底高含沙水流由起旋室的分流,渠道含沙量迅速降低,起旋室前部和后部渠底水流含沙量分别为44.00 kg/m^(3)和0.07 kg/m^(3);排沙洞内的旋转水流对泥沙的挟带作用明显,在强离心作用下泥沙主要分布在排沙洞近壁面,最大泥沙含量约为200.00 kg/m^(3);在持续来沙条件下旋流排沙渠道对粒径为(0.075,3.000]mm泥沙的截沙率为95.98%,仅少量极细泥沙以悬移质形式进入下游渠道,渠道和排沙洞内无大量的泥沙淤积,表明旋流排沙渠道是一种可实现高效且连续排沙的水沙分离技术。本成果可为旋流排沙渠道在工程中的应用和水沙特性的研究提供有益参考。 展开更多
关键词 旋流排沙渠道 水沙特性 数值模拟 离散相模型 截沙率
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