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Bioelectricity generation and remediation of sul de contaminatedtidal at sediment 预览
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作者 M.Azizul Moqsud 《国际泥沙研究:英文版》 SCIE 2020年第1期91-96,共6页
A dramatic decrease in the catch of shellfish has been observed due to the high amount of Acid Volatile Sulfide(AVS)in the tidal flats in Japan.In the current study,an evaluation of simultaneous bioelectricity generat... A dramatic decrease in the catch of shellfish has been observed due to the high amount of Acid Volatile Sulfide(AVS)in the tidal flats in Japan.In the current study,an evaluation of simultaneous bioelectricity generation and remediation of sulfide contaminated tidal flat sediment has been done.The sediment samples collected from Tokyo Bay and Yamaguchi Bay,Japan,have been used in the laboratory test.A 2 L cylindrical shaped Sediment Microbial Fuel Cell(SMFC)has been used to evaluate the remediation of both sediment samples in the laboratory.Three different electrode materials carbon felt,carbon fiber and bamboo charcoal were used in the experiments to compare their efficiency to reduce the AVS from the sediment and generate bioelectricity.It was observed that the AVS reduction was higher at 5 cm depths for the Tokyo Bay sediment(100%)compared to the Yamaguchi Bay sediment(60%).The larger grain size for the Tokyo Bay sediment was the probable reason for this.The maximum voltage was around 100 and 80 mV for Tokyo Bay and Yamaguchi Bay,respectively. 展开更多
关键词 Acid volatile sulfide BIOELECTRICITY REMEDIATION Tidal flat Sediment microbial fuel cell SEDIMENT
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Regularity of sediment transport and sedimentation during oods inthe lower Yellow River, China 预览
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作者 Qingchao Guo Zhao Zheng +1 位作者 Liemin Huang Anjun Deng 《国际泥沙研究:英文版》 SCIE 2020年第1期97-104,共8页
The flood season is the main period of flow,sediment transport,and sedimentation in the lower Yellow River(LYR).Within the flood season,most of the flow,sediment transport,and sedimentation occurs during flood events.... The flood season is the main period of flow,sediment transport,and sedimentation in the lower Yellow River(LYR).Within the flood season,most of the flow,sediment transport,and sedimentation occurs during flood events.Because of the importance of floods in forming riverbeds in the LYR,the regularity of sediment transport and sedimentation during floods in the LYR was studied.Measured daily discharge and sediment transport rate data for the LYR from 1960 to 2006 were used.A total of 299 floods were selected;these floods had a complete evolution of the flood process from the Xiaolangdi to the Lijin hydrological stations.For five hydrological stations(Xiaolangdi,Huayuankou,Gaocun,Aishan,and Lijin),a correlation was first established for floods of different magnitudes between the average sediment transport rate at a given station and the average sediment concentration at the closest upstream station.The results showed that the sediment transport rate at the downstream station was strongly correlated with the inflow(upstream station)sediment concentration during a flood event.A relation then was established between sedimentation in the LYR and the average sediment concentration at the Xiaolangdi station during a flood event.From this relation,the critical sediment concentrations were obtained for absolute erosion,sedimentation equilibrium,and absolute deposition during floods of different magnitudes in the LYR.The results of the current study contribute to a better understanding of the mechanisms of sediment transport and the regularity of sedimentation in the LYR during floods,and provide technical support to guide the joint operation of reservoirs and the regulation of the LYR. 展开更多
关键词 Sediment transport Floods SEDIMENTATION Lower Yellow River
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International Journal of Sediment Research(IJSR)-Order Form(2020)(ISSN 1001-6279) 预览
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《国际泥沙研究:英文版》 SCIE 2020年第1期I0002-I0004,共3页
IJSR is the journal of THE WORLD ASSOCIATION FOR SEDIMENTATION AND EROSION RESEARCH(WASER)and is edited by the International Research and Training Center on Erosion and Sedimentation(IRTCES).
关键词 SEDIMENTATION JOURNAL SEDIMENT
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Two-dimensional numerical simulation of sediment transport usingimproved critical shear stress methods 预览
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作者 Zhiyong Feng Guangming Tan +3 位作者 Junqiang Xia Caiwen Shu Peng Chen Ran Yi 《国际泥沙研究:英文版》 SCIE 2020年第1期15-26,共12页
Research on the critical shear stresses for erosion and deposition for cohesive sediment has attracted substantial attention from both engineering and theoretical viewpoints due to their importance in sediment transpo... Research on the critical shear stresses for erosion and deposition for cohesive sediment has attracted substantial attention from both engineering and theoretical viewpoints due to their importance in sediment transport theory.Previous studies have proposed a large number of empirical and semiempirical methods to estimate the critical erosion and deposition shear stress,but comparative analyses and validation of the existing methods are still lacking,leaving questions regarding the applicability ranges of the methods.The current paper evaluates the performance and applicability range of five critical erosion shear stress methods derived from different hypotheses on sediment transport for flume experiments and natural tidal rivers using a process-based model.In addition,the effect of the critical deposition shear stress on sediment transport is investigated.The results show that the different critical erosion shear stress methods yield distinctly different prediction results,and their performance and applicability ranges are discussed by comparing their predictions with measured sediment concentrations from the Shenzhen River and measured geometric changes from the Partheniades'flume experiment.The hiding and exposure effect has been recognized as a crucial factor in the incipient motion of sediment on nonuniform beds.A sensitivity analysis of selective deposition and continuous deposition justifies the existence of the critical deposition shear stress.The current study highlights the performance and applicability ranges of the existing critical shear stress methods in sediment transport modeling for uniform and nonuniform beds,which will enrich understanding of the underlying mechanisms of erosion and deposition of cohesive sediment. 展开更多
关键词 Cohesive sediment Critical shear stress Hiding and exposure effect Numerical modeling Shenzhen river
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菲与纳米银对胶州湾表层沉积物反硝化作用的复合毒性效应评价 预览
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作者 孙鹏飞 白洁 +3 位作者 李岿然 白晓岩 田延昭 赵阳国 《中国海洋大学学报:自然科学版》 CAS CSCD 北大核心 2020年第1期104-114,共11页
多环芳烃(PAHs)与纳米材料污染已对沉积物生态系统和人类生存环境构成严重威胁,其复合污染的毒性效应环境危害可能更大。为了深入探讨PAHs与纳米材料对近岸表层沉积物反硝化作用的复合毒性效应,本文选取位于胶州湾(JZB)的大沽河河口区(D... 多环芳烃(PAHs)与纳米材料污染已对沉积物生态系统和人类生存环境构成严重威胁,其复合污染的毒性效应环境危害可能更大。为了深入探讨PAHs与纳米材料对近岸表层沉积物反硝化作用的复合毒性效应,本文选取位于胶州湾(JZB)的大沽河河口区(DRE)E站和湾内S站,分别以菲和纳米银代表PAHs和纳米材料,通过测定不同剂量单一及复合污染下沉积物反硝化潜势(PDA)的变化,结合浓度相加模型(CA)、独立作用模型(IA)和中效/联合指数等效图法(CI)三种复合毒性评价方法,评价菲和纳米银对沉积物反硝化潜势的复合毒性效应,并对评价方法进行了优选。结果表明,两种污染物浓度越高,对研究区域反硝化潜势的抑制作用越大。菲、纳米银单一及复合作用下对河口区沉积物反硝化潜势的EC50值分别为44.62、112.49和64.86 mg·kg-1,对湾内分别为61.79、147.05和96.18 mg·kg-1。菲单一作用对反硝化潜势的抑制效应强于纳米银,但复合污染的抑制效应更强。两种污染物对河口区的沉积物反硝化潜势抑制效应强于湾内,可能与河口区具有较高Eh和沉积物颗粒度及较低的pH、盐度和有机质含量有关。三种毒性效应评价方法的结果表明,菲和纳米银的复合污染对2个站位反硝化潜势的毒性效应均为协同作用,且对大沽河河口区的协同作用更强。此外,CI法对复合效应的预测结果比CA和IA法更为接近实际观测值,且CI不需要考虑污染物作用模式的限制,因此认为CI法更适用于评价混合污染对沉积物反硝化作用复合影响的效果。本研究结果表明,菲和纳米银会增强彼此对反硝化菌及反硝化功能的毒性效应,由此推断,PAHs和纳米材料在环境中同时存在时比其单独存在对沉积环境的危害更大。 展开更多
关键词 纳米银 沉积物 反硝化作用 复合毒性
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Experimental study of near-bed concentration and sediment verticalmixing parameter for vertical concentration distribution in the surfzone 预览
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作者 Yang Zhang Zhili Zou +1 位作者 Wushan Xue Dapeng Sun 《国际泥沙研究:英文版》 SCIE 2020年第1期27-41,共15页
Two formulae for the near-bed concentration(Ca)and the sediment vertical mixing parameter(m)are established based on a large scale wave flume experiment.The advantage of the new formulae is that the turbulent kinetic ... Two formulae for the near-bed concentration(Ca)and the sediment vertical mixing parameter(m)are established based on a large scale wave flume experiment.The advantage of the new formulae is that the turbulent kinetic energy induced by wave breaking can be taken into account;the formula for Ca is in terms of the near-bed,time-averaged turbulent kinetic energy,and the formula for m is in terms of depth-and time-averaged turbulent kinetic energy.A new expression for suspended sediment load also is established by depth integration of the vertical distribution of the suspended sediment concentration obtained on basis of the new formulae.Equation validation is done by comparing the predicted Ca and m to measurements for different types of waves(regular wave,wave group,and irregular wave),and good agreement is found.The advantages of the proposed formulae over previous formulae also are discussed. 展开更多
关键词 Near-bed concentration Sediment vertical mixing parameter Turbulent kinetic energy Surf zone Wave type
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The uncertainty of the Shannon entropy model for shear stressdistribution in circular channels 预览
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作者 Amin Kazemian-Kale-Kale Hossein Bonakdari +1 位作者 Azadeh Gholami Bahram Gharabaghi 《国际泥沙研究:英文版》 SCIE 2020年第1期57-68,共12页
The shear stress distribution at alluvial stream beds and banks is one of the essential parameters in channel stability analysis.In the current paper,a novel uncertainty analysis method based on the framework of a Bay... The shear stress distribution at alluvial stream beds and banks is one of the essential parameters in channel stability analysis.In the current paper,a novel uncertainty analysis method based on the framework of a Bayesian Forecasting System(BFS)is presented to evaluate the Shannon entropy model for prediction of the shear stress distribution in both circular rigid-bed and alluvial-bed channels.The Johnson and Box-Cox transformation functions were applied to select the optimum sample size(SS)and corresponding transformation factor for determining a 95%confidence bound(CB)for the Shannon entropy model.The Shapiro-Wilk(SW)test is applied according to the SS used to evaluate the power of transformation functions in the data normalization.The results show that the error distribution between predicted and experimental shear stress values generated using the Box-Cox transformation is closer to a Gaussian distribution than the generated using the Johnson transformation.The indexes of the percentage of the experimental values within the CB(Nin)and Forecast Range Error Estimate(FREE)are applied for the uncertainty analyses.The lower values of FREE equal to 1.724 in the circular rigid-bed channel represent the low uncertainty of Shannon entropy in the prediction of shear stress values compared to the uncertainty for the circular alluvial-bed channel with a FREE value equal to 7.647. 展开更多
关键词 Uncertainty analysis Shear stress distribution Shannon entropy Confidence bound Johnson transformation Box-Cox transformation Circular with sediment bed
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Appraisal of the carbon to nitrogen (C/N) ratio in the bed sediment ofthe Betwa River, Peninsular India 预览
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作者 Madavi Venkatesh Anshumali 《国际泥沙研究:英文版》 SCIE 2020年第1期69-78,共10页
Bed sediment carbon to nitrogen(C/N)ratio is one of the essential variables reflecting sources of organic matter in river basins.In order to explore the spatial variability in sources of sediment C/N ratios,and the in... Bed sediment carbon to nitrogen(C/N)ratio is one of the essential variables reflecting sources of organic matter in river basins.In order to explore the spatial variability in sources of sediment C/N ratios,and the influence of land use and land cover(LULC)changes on the Betwa River basin in Peninsular India,51 river bed sediment samples were collected in December 2016.The coefficient of variation(CV)was>35%indicating highly variable biogeochemical parameters.The sediment C/N ratio varied from 2.94 to 10.09,3.21e56.40,and 6.50e76.97 in upstream,mid-stream,and downstream regions,respectively,indicating a progressive change in sources of organic matter and depositional environment.The positive correlation between total carbon(TC)and C/N ratio was increasing in the downstream direction[upstream(t0.560)<mid-stream(t0.603)<downstream(t0.838)],which is an indication of high deposition and slow decomposition of sedimentary terrigenous organic matter distant from the regions of urban pollution.The LULC change analysis done by remote sensing and Geographic Information System(GIS)methods revealed an adverse change for the forests and barren land and a positive change for the agricultural land and built-up areas.The sediment C/N ratio mapping showed the impact of LULC changes on the sediment quality.The spatial distribution of bed sediment C/N ratio in the Betwa River basin has important reference value for managing organic matter transport in the downstream Yamuna River and Ganga River basin. 展开更多
关键词 Bed sediment C/N ratio ANOVA analysis Bundelkhand region Marginal alluvial plain
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Linear spectral unmixing algorithm for modelling suspendedsediment concentration of ash oods, upper Tekeze River, Ethiopia 预览
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作者 Hagos GGebreslassie Assefa MMelesse +1 位作者 Kevin Bishop Azage GGebremariam 《国际泥沙研究:英文版》 SCIE 2020年第1期79-90,共12页
Flash floods are the highest sediment transporting agent,but are inaccessible for in-situ sampling and have rarely been analyzed by remote sensing technology.Laboratory and field experiments were done to develop linea... Flash floods are the highest sediment transporting agent,but are inaccessible for in-situ sampling and have rarely been analyzed by remote sensing technology.Laboratory and field experiments were done to develop linear spectral unmixing(LSU)remote sensing model and evaluate its performance in simulating the suspended sediment concentration(SSC)in flash floods.The models were developed from continuous monitoring in the laboratory and the onsite spectral signature of river bed sediment deposits and flash floods in the Tekeze River and in its tributary,the Tsirare River.The Pearson correlation coefficient was used to determine the variability of correlations between reflectance and SSCs.The coefficient of determination(R2)and root mean square of error(RMSE)were used to evaluate the performance of the generated models.The results found that the Pearson correlation coefficient between SSCs and reflectance varied based on the level of the SSCs,geological colors,and grain sizes.The performance of the LSU model and empirical remote sensing approaches were computed to be R2?0.92,and RMSE-±0.76 g/l in the Tsirare River and R2-0.91,and RMSE-±0.73 g/l in the Tekeze River and R2?0.81,RMSE-±2.65 g/l in the Tsirare river and R2?0.76,RMSE-±10.87 g/l in the Tekeze River,respectively.Hence,the LSU approach of remote sensing was found to be relatively accurate in monitoring and modeling the variability of SSCs that could be applied to the upper Tekeze River basin. 展开更多
关键词 Empirical remote sensing Flash floods Linear spectral unmixing Suspended sediment concentration Tekeze River
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黄土区工程堆积体陡坡坡面径流调控工程措施的减沙效应 预览
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作者 张乐涛 董俊武 +7 位作者 袁琳 朱雅琴 黄增玉 李婉璐 王慧慧 唐林昊 田红卫 高照良 《农业工程学报》 EI CAS CSCD 北大核心 2019年第15期101-109,共9页
定量分析减少径流和改变水沙关系在泥沙调控中的不同作用,对于深刻理解径流调控措施的水土保持效益具有重要意义。以黄土区工程堆积体陡坡坡面(36°)为例,探讨了野外模拟径流冲刷试验条件下,不同工程措施及其组合调控坡面径流的水... 定量分析减少径流和改变水沙关系在泥沙调控中的不同作用,对于深刻理解径流调控措施的水土保持效益具有重要意义。以黄土区工程堆积体陡坡坡面(36°)为例,探讨了野外模拟径流冲刷试验条件下,不同工程措施及其组合调控坡面径流的水沙效应及其作用效率。结果表明:1)不同工程措施均能较好地调控坡面径流侵蚀过程,不同情形下的产流时间控制比为2~20,径流量控制比为0.45~0.78,产沙量控制比为0.20~0.59;平均含沙量控制比为0.38~0.79;2)减流控沙作用是工程措施调控坡面侵蚀产沙的主要原因,水沙关系调沙作用则受减流控沙作用的制约;3)水平阶类措施的水沙关系调沙量与减流控沙量呈线性正相关,当减流控沙量超过一定临界值时,水沙关系才开始发挥调沙作用;水平沟类措施的水沙关系调沙量与减流控沙量呈二次函数关系,水沙关系调沙量存在极大值;4)水平沟类措施调控泥沙的作用效率高于水平阶类措施,水平沟+鱼鳞坑的组合可很好地发挥减流控沙和水沙关系调沙作用的潜力(55%),使二者在较高的水平上维持相对平衡;因此,不同工程措施与组合的实际应用应以具体的水土保持效益和防治目标为布设依据。研究可为堆积体陡坡治理的工程措施优化提供理论参考。 展开更多
关键词 侵蚀 泥沙 径流 水沙关系 泥沙调控能力 效率系数 弃土堆积体
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Development of benthic macroinvertebrates sediment index (BSI) for bioassessment of freshwater sediment 预览
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作者 Pil Jae Kim Jong Hyeon Lee +1 位作者 In Ae Huh DongSoo Kong 《国际泥沙研究:英文版》 SCIE 2019年第4期368-378,共11页
Sediment quality has been evaluated in a variety of ways since the early 1990s in studies from Europe. In South Korea, most studies have used an indicator value for benthic macroinvertebrates based on water quality, n... Sediment quality has been evaluated in a variety of ways since the early 1990s in studies from Europe. In South Korea, most studies have used an indicator value for benthic macroinvertebrates based on water quality, not sediment quality. To date, few studies have examined the biological integrity of benthic macroinvertebrate communities in South Korea. In the current study, the tolerance valency and value in samples and the indicator weight values were measured for 43 benthic macroinvertebrate taxa from 73 sampling units in South Korea from 2014 to 2016. Total organic carbon, the amount of heavy metals, and total ammonia nitrogen were analyzed. The average grade for each pollutant was used as the sediment quality index. A benthic macroinvertebrates sediment index was developed for bioassessment of freshwater sediment. The benthic macroinvertebrates sediment index, which is based on the relative frequency of occurrence of macroinvertebrates, was highly correlated with pollution levels in the sediment. This index can be used in the field to assess the contamination of freshwater sediment. As the sample size was small in the current study and there were taxonomic limitations of Chironomidae larvae, further research is needed to improve the reliability of the benthic macroinvertebrates sediment index. 展开更多
关键词 BENTHIC MACROINVERTEBRATES BIOASSESSMENT FRESHWATER SEDIMENT SEDIMENT quality INDEX
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Turbulence and suspended sediment processes in the Garonne Rivertidal bore in November 2016 预览
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作者 David Reungoat Xinqian Leng Hubert Chanson 《国际泥沙研究:英文版》 SCIE 2019年第5期496-508,共13页
A tidal bore is a water discontinuity at the leading edge of a ood tide wave in estuaries with a large tidal range and funneling topography. New measurements were done in the Garonne River tidal bore on 14 15 November... A tidal bore is a water discontinuity at the leading edge of a ood tide wave in estuaries with a large tidal range and funneling topography. New measurements were done in the Garonne River tidal bore on 14 15 November 2016, at a site previously investigated between 2010 and 2015. The data focused on long, continuous, high-frequency records of instantaneous velocity and suspended sediment con- centration (SSC) estimate for several hours during the late ebb, tidal bore passage and ood tide. The bore passage drastically modi ed the ow eld, with very intense turbulent and sediment mixing. This was evidenced with large and rapid uctuations of both velocity and Reynolds stress, as well as large SSCs during the ood tide. Granulometry data indicated larger grain sizes of suspended sediment in water samples compared to sediment bed material, with a broader distribution, shortly after the tidal bore. The tidal bore induced a sudden suspended sediment ux reversal and a large increase in suspended sedi- ment ux magnitude. The time-variations of turbulent velocity and suspended sediment properties indicated large uctuations throughout the entire data set. The ratio of integral time scales of SSC to velocity in the x-direction was on average TE,SSC/TE,x 0.16 during the late ebb tide, compared to TE,SSC/ TE,x 0.09 during the late ood tide. The results imply different time scales between turbulent velocities and suspended sediment concentrations. 展开更多
关键词 TIDAL BORE Garonne RIVER HYDRODYNAMICS Suspended SEDIMENT Field observations Turbulence-sediment suspension interactions
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Development and Application of an in Situ Penetrator for Rapid Strength Testing of Submarine Sediment 预览
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作者 ZHANG Minsheng WANG Zhenhao +2 位作者 WANG Xiuhai WEN Mingzheng HONG Bo 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第2期328-338,共11页
In marine engineering,the strength of a submarine sediment is an indispensable parameter for assessment of construction.In this study,a free-fall cone penetrator named IPen was developed to realize a rapid and efficie... In marine engineering,the strength of a submarine sediment is an indispensable parameter for assessment of construction.In this study,a free-fall cone penetrator named IPen was developed to realize a rapid and efficient measurement of sediment strength.The equipment is characterized by modular design and self-contained data acquisition.It is equipped with an acceleration sensor,a water pressure sensor,and a piezocone penetration test(CPTu)probe.It is designed to be released from near seabed surface with a releaser and then fall freely to provide a higher penetration velocity.Its maximum working depth is approximately 2500m and maximum penetration depth is approximately 3 m.To derive the correlation between penetration resistance and sediment strength,a calibrator was devised to determine the penetration-rate factor.In addition,the factor applicable to in situ test points was determined in laboratory experiments.In June 2016,the IPen was tested in situ in the South Yellow Sea,China,during a shared voyage funded by the National Science Foundation.Meanwhile,undisturbed column samples were collected for laboratory tests.Based on the in situ test results,it was demonstrated that the IPen could accurately record the working states of various sensors during the freely falling course.IPen test results reliably reflected the sediment strength at all the testing points when compared with laboratory calibration tests,in situ vane tests and penetration tests,laboratory penetration tests,and unconsolidated and undrained triaxial compression tests. 展开更多
关键词 SUBMARINE SEDIMENT free-fall CONE PENETRATION test SEDIMENT strength the Yellow Sea penetration-rate factor
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夏季东、黄海沉积物中甲烷的分布和沉积物-水界面通量 预览
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作者 叶旺旺 谷雪霁 +2 位作者 康绪明 刘素美 张桂玲 《海洋科学》 CAS 北大核心 2019年第7期77-86,共10页
沉积物释放是海洋环境中甲烷(CH4)的重要来源。通过2013年7月和8月两个航次,对东、黄海泥质区沉积物中CH4浓度的垂直分布和沉积物-水界面通量进行了研究。结果表明,除个别站位外,黄海沉积物(50cm以浅)中CH4的浓度变化范围在0.2~1.0μmo... 沉积物释放是海洋环境中甲烷(CH4)的重要来源。通过2013年7月和8月两个航次,对东、黄海泥质区沉积物中CH4浓度的垂直分布和沉积物-水界面通量进行了研究。结果表明,除个别站位外,黄海沉积物(50cm以浅)中CH4的浓度变化范围在0.2~1.0μmol/L之间,长江口及浙闽沿岸附近的沉积物中CH4浓度则要更高(1.0~2.0μmol/L),而东海东部海域沉积物中CH4浓度波动范围为0.2~3.0μmol/L。总体来说,东、黄海沉积物中CH4浓度偏低,这可能与观测到的高浓度硫酸盐(>20mmol/L)有关。通过整柱密室培养实验估算出东、黄海沉积物-水界面CH4释放速率在0.64~2.12μmol/(m^2·d)之间,东、黄海沉积物CH4释放总量为6.7×10^8mol/yr;但采用菲克定律估算的CH4扩散通量则要比现场培养的结果低2~5倍,表明不同的方法在估算沉积物-水界面CH4通量上还具有一定的不确定性。 展开更多
关键词 东海 沉积物 甲烷 硫酸盐 沉积物-水界面通量
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基于小流域尺度的黔北喀斯特地区产流产沙特征 预览
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作者 李瑞 陈康 +4 位作者 刘瑞禄 顾再柯 文雅琴 黎庆贵 刘凤仙 《农业工程学报》 EI CAS CSCD 北大核心 2019年第11期139-147,共9页
目前,中国西南喀斯特地区流域尺度产流产沙长期定位观测试验报道较少,且其相关机制的探讨不足。该文基于小流域尺度,分析典型喀斯特小流域产流产沙特征,定性、定量探讨喀斯特小流域产流产沙的主要影响因子。选取位于贵州北部的典型喀斯... 目前,中国西南喀斯特地区流域尺度产流产沙长期定位观测试验报道较少,且其相关机制的探讨不足。该文基于小流域尺度,分析典型喀斯特小流域产流产沙特征,定性、定量探讨喀斯特小流域产流产沙的主要影响因子。选取位于贵州北部的典型喀斯特小流域-遵义浒洋水小流域为研究区,采用小流域控制站定位观测法,在4年连续观测的基础上,分析浒洋水小流域月际、年际产流产沙特征,并重点分析了降雨对小流域产流产沙的影响。结果表明:受喀斯特地区特殊的"二元"侵蚀环境等因素影响,浒洋水小流域产流、产沙高峰不同期,产流高峰出现在10月,多年月均值为63.9万m^3,而产沙高峰为6月,116.21t。显著性检验则表明,浒洋水小流域月际产流无显著差异(P>0.05),但6月产沙则显著高于1、2、3及12月(P<0.05),其他月份间产沙无显著差异(P>0.05);受年度降雨的影响,2010-2013年,无论是产流还是产沙,2013年均显著高于其他年份(P<0.05)。研究期间,小流域多年平均输沙模数为215.32 t/(km2·a),这一结果与贵州省公布的贵州喀斯特区土壤侵蚀模数279.47t/(km2·a)接近;该小流域降雨对产流产沙影响显著,降雨强度(I60)同产流产沙在0.05水平上显著相关,而降雨量同产流产沙则在0.01水平上显著相关。结果可为喀斯特地区的水土流失治理提供参考。 展开更多
关键词 流域 侵蚀 径流 喀斯特 黔北 坡面尺度 产沙 输沙模数 浒洋水
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Effects of rainfall patterns on runoff and rainfall-induced erosion 预览
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作者 Morteza Alavinia Farzin Nasiri Saleh Hossain Asadi 《国际泥沙研究:英文版》 SCIE 2019年第3期270-278,共9页
Rainfall-induced erosion involves the detachment of soil particles by raindrop impact and their transport by the combined action of the shallow surface runoff and raindrop impact.Although temporal variation in rainfal... Rainfall-induced erosion involves the detachment of soil particles by raindrop impact and their transport by the combined action of the shallow surface runoff and raindrop impact.Although temporal variation in rainfall intensity(pattern)during natural rainstorms is a common phenomenon,the available information is inadequate to understand its effects on runoff and rainfall-induced erosion processes.To address this issue,four simulated rainfall patterns(constant,increasing,decreasing,and increasing-decreasing)with the same total kinetic energy were designed.Two soil types(sandy and sandy loam)were subjected to simulated rainfall using 15 cm×30 cm long detachment trays under infiltration conditions.For each simulation,runoff and sediment concentration were sampled at regular intervals.No obvious difference was observed in runoff across the two soil types,but there were significant differences in soil losses among the different rainfall patterns and stages.For varying-intensity rainfall patterns,the dominant sediment transport mechanism was not only influenced by raindrop detachment but also was affected by raindrop-induced shallow flow transport.Moreover,the efficiency of equations that predict the interrill erosion rate increased when the integrated raindrop impact and surface runoff rate were applied.Although the processes of interrill erosion are complex,the findings in this study may provide useful insight for developing models that predict the effects of rainfall pattern on runoff and erosion. 展开更多
关键词 RAINFALL pattern SEDIMENT CONCENTRATION Soil LOSS SEDIMENT transport mechanisms
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典型盐碱地改良区农田排水沟水体与底泥界面氧通量研究 预览
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作者 潘延鑫 冯绍元 +2 位作者 罗纨 贾忠华 井思媛 《水利学报》 EI CSCD 北大核心 2019年第7期835-843,共9页
农田排水沟水体与底泥中的氧含量决定了底泥中各种生源要素的最终归趋,对维持农田排水沟的水环境至关重要。本论文以陕西富平县卤泊滩盐碱地改良区农田排水沟水体与底泥为研究对象,从环境微界面角度出发,根据多年监测数据构建室内试验,... 农田排水沟水体与底泥中的氧含量决定了底泥中各种生源要素的最终归趋,对维持农田排水沟的水环境至关重要。本论文以陕西富平县卤泊滩盐碱地改良区农田排水沟水体与底泥为研究对象,从环境微界面角度出发,根据多年监测数据构建室内试验,采用高分辨率微环境固液剖面传感系统(丹麦Unisense微电极系统),探究了研究区农田排水沟水体与底泥界面氧通量变化规律。研究结果表明:底泥中的溶解氧随深度的增加逐渐减小,直至溶解氧浓度为零,到达厌氧层;溶解氧剖面浓度的实测值与Profile模型模拟值的相关系数均在0.995以上,表明该模型能客观地描述溶解氧在农田排水沟水体与底泥扩散边界层和底泥中的分布;农田排水沟上游不同监测点位的底泥含氧层厚度在3.5~6 mm之间,而下游监测点位的底泥含氧层厚度约为1.5 mm,差异显著;通过氧浓度线性分布、剖面拐点法得到氧气扩散边界厚度,上游监测点位的氧气扩散边界层厚度基本在1 mm,而下游监测点位的氧气扩散边界层厚度减少至0.2 mm。农田排水沟水体与底泥界面氧通量的测定,对于认识农田排水沟底泥的地球化学过程及水环境作用机理具有重要意义,可为农田排水沟水环境治理提供参考依据。 展开更多
关键词 农田排水沟 底泥 界面 扩散边界层 氧通量
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Two-thousand years of debates and practices of Yellow River training strategies 预览
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作者 Zhaoyin Wang Cheng Liu 《国际泥沙研究:英文版》 SCIE 2019年第1期73-83,共11页
Throughout the history of China,the Yellow River has been associated with flood disasters and changes in the course of its lower reaches because of sedimentation.From 602 B.C.to 1949 the river experienced 1593 levee b... Throughout the history of China,the Yellow River has been associated with flood disasters and changes in the course of its lower reaches because of sedimentation.From 602 B.C.to 1949 the river experienced 1593 levee bursts,flooding vast areas,and claiming millions of human lives.The river shifted its main course by avulsion 26 times with the apex around Zhengzhou,resulting in devastating calamities and numerous old channels.Training of the Yellow River has a history of more than 3000 yr.Levee construction has been the major strategy for flood control.Two extremely different strategies has been proposed and practiced in the past 2000 yr,i.e.the“wide river and depositing sediment”strategy and the“narrow river and scouring sediment”strategy.This paper analyzes the levee breaches and flood disasters in the past 2000 yr and compares the results of the two extremely different strategies.The“narrow river and scouring sediment”strategy has only short term effects on levee breach control and flood mitigation.The“wide river and depositing sediment”strategy can essentially mitigate flood disasters and reduce levee breaches for a long term period of time.The“wide river and depositing sediment”strategy has been used and no levee breach has occurred in the past 67 yr,which has been the only periods of more than 50 yr with no levee breaches in the history of the Yellow River since 700 A.D.Modern flood and sedimentation management methods have also been introduced,and the strategy of applying the“widen the river and enhance the levees”approach for the upper and lower reaches management is proposed. 展开更多
关键词 Yellow RIVER LEVEE breaches AVULSION Wide RIVER and depositing SEDIMENT STRATEGY Narrow RIVER and SCOURING SEDIMENT STRATEGY
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Application of Bayesian model and discriminant function analysis to the estimation of sediment source contributions 预览
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作者 Pengfei Du Donghao Huang +4 位作者 Duihu Ning Yuehong Chen Bing Liu Jian Wang Jingjing Xu 《国际泥沙研究:英文版》 SCIE 2019年第6期577-590,共14页
Bayesian and discriminant function analysis(DFA)models have recently been used as tools to estimate sediment source contributions.Unlike existing multivariate mixing models,the accuracy of these two models remains unc... Bayesian and discriminant function analysis(DFA)models have recently been used as tools to estimate sediment source contributions.Unlike existing multivariate mixing models,the accuracy of these two models remains unclear.In the current study,four well-distinguished source samples were used to create artificial mixtures to test the performance of Bayesian and DFA models.These models were tested against the Walling-Collins model,a credible model used in estimation of sediment source contributions estimation,as a reference.The artificial mixtures were divided into five groups,with each group consisting of five samples with known source percentages.The relative contributions of the sediment sources to the individual and grouped samples were calculated using each of the models.The mean absolute error(MAE)and standard error of(SE)MAE were used to test the accuracy of each model and the robustness of the optimized solutions.For the individual sediment samples,the calculated source contributions obtained with the Bayesian(MAE?7.4%,SE?0.6%)and Walling-Collins(MAE?7.5%,SE?0.7%)models produced results which were closest to the actual percentages of the source contributions to the sediment mixtures.The DFA model produced the worst estimates(MAE?18.4%,SE?1.4%).For the grouped sediment samples,the Walling-Collins model(MAE?5.4%)was the best predictor,closely followed by the Bayesian model(MAE?5.9%).The results obtained with the DFA model were similar to the values for the individual sediment samples,with the accuracy of the source contribution value being the poorest obtained with any of the models(MAE?18.5%).An increase in sample size improved the accuracies of the Walling-Collins and Bayesian models,but the DFA model produced similarly inaccurate results for both the individual and grouped sediment samples.Generally,the accuracy of the Walling-Collins and Bayesian models was similar(p>0.01),while there were significant differences(p<0.01)between the DFA model and the other models.This study demonstrated that the Bayesian mo 展开更多
关键词 SEDIMENT fingerprinting SEDIMENT source contribution Walling-Collins MODEL BAYESIAN MODEL DISCRIMINANT function analysis
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Numerical Study on Seasonal Transportation of the Suspended Sediments in the Modern Yellow River Mouth Effected by the Artificial Water and Sediment Regulation 预览
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作者 WANG Nan QIAO Lulu +5 位作者 LI Guangxue ZHONG Yi SONG Dehai DING Dong GAO Fei JI Fengying 《中国海洋大学学报:英文版》 SCIE CAS CSCD 2019年第1期20-30,共11页
Since 2002,an artificial water and sediment regulation(AWSR)has been carried out,which largely reduced water and sediment discharged from the Yellow River into the Bohai Sea.Although the sediment transport in the Yell... Since 2002,an artificial water and sediment regulation(AWSR)has been carried out,which largely reduced water and sediment discharged from the Yellow River into the Bohai Sea.Although the sediment transport in the Yellow River Mouth(YRM)has been observed and modeled intensively since AWSR,but preferentially for the non-storm conditions.In this study,a three-dimensional current-wave-sediment coupled model,DHI-MIKE numerical model,was used to examine the seasonal suspended-sediment transport in the YRM after the AWSR.Results show that the seasonal distribution of suspended-sediments in the YRM is dominated by wind and wave rather than river input.The major transport pathway of suspended-sediments is from the western Laizhou Bay to the Bohai Strait during the winter monsoon,especially in storm events.In addition,about 66%of the river sediments deposit within 30km of the YRM,which is smaller than previous estimations.It suggests that the YRM has been eroded in recent decades. 展开更多
关键词 YELLOW River MOUTH artificial water and SEDIMENT regulation MIKE suspended-sediment transport SEASONAL variation
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