Simulation of the Fate of Faecal Bacteria in Estuarine and Coastal Waters Based on A Fractionated Sediment Transport Model     

YANG Chen  LIU Ying 《海洋工程》2017,31(4):389-395

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.  相似文献   

东部沿海十省市旅游投资环境评价研究     

庄玥  严艳  刘畅 《地理信息世界》2017,24(4)

目前,旅游业已经成为国民经济发展中的重要产业,而旅游业的发展需要外部资金的支持,因此,能否吸引外来资金是一个关系旅游业能否可持续发展的重要问题~([1])。本文尝试构建包含经济环境、旅游业发展、区域条件和外部环境4个层面共32个指标的旅游投资环境评价指标体系,运用因子分析法对我国东部沿海十省市的旅游投资环境进行了综合测评与排序。结果显示,广东省旅游投资环境最好,河北的最差。广东省的各项指标值均高于其他省市,说明其投资吸引力最强。而其他省市各有优劣之处,建议在以后的发展中逐渐改善劣势从而达到改善旅游投资环境。  相似文献   

福建省海岸带脆弱生态环境信息图谱研究   总被引：2，自引：0，他引：2  

陈菁 《地球信息科学学报》2010,12(2):159-166

海岸带是陆地和海洋的交接地带,随着沿海经济的发展和对外开放,对海岸带的各种开发活动,一方面促进了沿海地区的经济发展,另一方面也使海岸带面临的压力越来越大,如人口增多、资源消耗、环境污染严重等。此外,海岸带的自然灾害频繁,常见的有台风、干旱和地震,海岸带生态环境呈现出典型脆弱性的特征。以地学信息图谱的方法论对海岸带脆弱生态环境进行研究:首先,它依托由对地观测技术、实地调查及社会经济统计而建立起的时空数据库,通过数据挖掘与知识发现,产生征兆图谱;然后,结合评价和时空分析模型及G IS提取诊断图谱;最后,在预测模型的支持下产生实施图谱,从而形成决策方案。实践证明,通过信息图谱能够更直观地反映海岸带脆弱生态环境,包括其现状、驱动因素,以及未来变化趋势,为海岸带的可持续发展规划决策、环境管理,以及防灾减灾对策的制定提供重要的科学依据。  相似文献   

Bloom forming species of phytoplankton in two coastal waters in the Southeast coast of India     

K. Thillai Rajasekar  M. Rajkumar  Jun Sun  V. Ashok Prabu  P. Perumal 《中国海洋大学学报(英文版)》2010,9(3):265-272

The results of an investigation carried out during June 2005 to May 2007 on bloom-forming phytoplankton species composition and abundance in the Parangipettai and Coleroon coastal waters(Southeast coast of India) are reported.Air and surface water temperatures(℃) varied from 25.1 to 30.1 and 24.5 to 28.5,respectively,in the former waters and from 25.5 to 31.2 and 25.0 to 29.3 in the latter waters.The respective salinities varied from 6.0 to 28.5 and 5.0 to 33.1 and the respective pH ranged between 7.0 and 8.3 and 7.2 and 8.3.Correspondingly,the dissolved oxygen content varied from 3.1 to 7.5 and 3.1 to 7.9 mgL-1 while the light extinction coefficient(LEC) values ranged between 3.1 and 10.1 and 1.8 and 11.0.The content ranges of inorganic nutrients,i.e.,nitrate,nitrite,phosphate and silicate(μmolL-1),in the Parangipettai and Coleroon coastal waters were:6.5-27.0;1.0-8.9;0.1-3.0 and 15.0-140 and 10.1-23.4;1.2-8.9;0.2-3.1 and 55-125 respectively.The chlorophyll a contents in both waters ranged from 2.0-7.5 μgL-1.Presently,124 phytoplankton species representing different classes were recorded in the Coleroon coast,viz,Bacillariophyceae(77);Dinophyceae(19);Cyanophyceae(15);Chlorophyceae(10) and Chrysophyceae(3),whereas 117 phytoplankton species were recorded in the Parangipettai coast,viz,Bacillariophyceae(66);Dinophyceae(22);Cyanophyceae(19);Chlorophyceae(7) and Chrysophyceae(3).The phytoplankton cell abundance in the Parangipettai and Coleroon coastal waters varied from 290 to 111662 and 140 to 132 757 cells L-1,respectively,with peak diversity(3.38 and 3.52 bits ind-1.) recorded in summer.The maximum abundance occurred in summer coinciding with the stable hydrographical conditions.The seasonal distribution and abundance of phytoplankton are discussed in relation to hydrographical parameters.Totally 31 and 24 species of phytoplankton were found to be bloom-forming in the Parangipettai and Coleroon coastal waters,respectively.Presently Trichodesmium bloom was also observed,which appeared at the 10 fathom level of the coastal water and quickly spread to the marine zone of the Vellar estuary and near the mouth region of the mangrove waters.The Parangipettai and Coleroon coastal waters are subject to long term fluctuations in physico-chemical conditions depending upon the seasonal tidal range and freshwater influx,resulting in a continuous exchange of organic,inorganic,plant and animal matters.  相似文献   

Reappraising the geomorphology‐ecology link     

Stephen E Darby 《地球表面变化过程与地形》2010,35(3):368-371

This thematic Virtual Special Issue highlights a personal selection of 18 recent (2007–2009) contributions to Earth Surface Processes and Landforms. These papers provide a flavour of recent research that is concerned with furthering our understanding of the many ways in which the biosphere interacts with the physical and chemical processes of sediment transfer/transformation. Much of this research has focused on understanding the mechanics by which the biota can modulate sediment transport and the strength of earth surface materials, often with the aim of applying that knowledge to enhance bioremediation methods of erosion control. This work continues to be fundamentally important in enhancing our understanding of earth surface processes, but often treats the biosphere and physical world as uncoupled entities. This selection therefore also provides samples of work that point to an ongoing but significant disciplinary reappraisal in which it is the interactions between ecological and geomorphological realms that are of primary interest. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Coastal foredune topography as a control on secondary airflow regimes under offshore winds   总被引：1，自引：0，他引：1  

Kevin Lynch  Derek W. T. Jackson  J. Andrew G. Cooper 《地球表面变化过程与地形》2010,35(3):344-353

  相似文献   

Stir bar sorptive extraction-thermal desorption-gas chromatography-mass spectrometry: An effective tool for determining persistent organic pollutants and nonylphenol in coastal waters in compliance with existing Directives   总被引：1，自引：0，他引：1  

Juan Sánchez-Avila  Francesc Ventura  Carlos M. Duarte 《Marine pollution bulletin》2010,60(1):103-160

A multi-residual method based on stir bar sorptive extraction coupled with thermal desorption-gas chromatography-mass spectrometry (SBSE-TD-GC-MS) has been developed to measure 49 organic pollutants (organochlorine pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polybrominated diphenyl ethers and nonylphenol) in seawater. Using 100 ml of water, the method exhibited good linearity, with recoveries between 86% and 118% and relative standard deviation between 2% and 24% for almost all compounds. The method was applied to determine target contaminants in Catalonian seawater, including coastal areas, ports and desalination plant feed water. Overall individual compound levels oscillated between 0.16 and 597 ng l⁻¹; PAHs and nonylpenol were the compounds found at the highest concentrations. The method provided LODs between 0.011 and 2.5 ng l⁻¹, lower than the Environmental Quality Standards (EQS) fixed by Directive 2008/105/EC. In compliance with the directive, this method can be used as a tool to survey target compounds and is aimed at protecting coastal ecosystems from chemical pollution.  相似文献   

山东沿海地区地震海啸研究     

冯志泽  张建民  陈惠云 《华北地震科学》2010,28(1):26-30

地震海啸是一种极其严重的地震次生灾害。山东是世界上最早记录地震海啸的地区。收集整理了山东沿海地区记载的7次地震海啸史料,对每次地震海啸进行了信度评级,认为仅有一次可能是海啸。根据山东沿海地区历史地震海啸、地震类型、沿海地理环境、现代地震海啸记录资料等分析,表明山东沿海未来遭受破坏性地震海啸的可能性较小。  相似文献   

Erosion and accretion processes in a muddy dissipative coast,the Chao Phraya River delta,Thailand     

Katsuto Uehara  Pramot Sojisuporn  Yoshiki Saito  Thanawat Jarupongsakul 《地球表面变化过程与地形》2010,35(14):1701-1711

Seasonal variation in seabed elevation in the muddy intertidal zone of the Chao Phraya River delta, an area of serious coastal erosion for 40 years, was assessed using information on waves and tides predicted by numerical simulations. The study area is under the influence of the Southeast Asian monsoon climate and lies in the innermost part of a sheltered gulf, across which a low‐gradient slope has developed. Observations, aimed at evaluating the effectiveness of a prototype breakwater on mitigating coastal erosion, indicated that the seasonal variation in the seabed elevation, typically about 30 cm, was caused primarily by seasonal changes in wave direction and height. The breakwater seems to have contributed to a net rise in the seabed level at sites behind the structure. Seabed erosion was most apparent during the northeast monsoon, when waves are weak. Erosion under this low wave energy state was attributed to the combined effect of wave breaking and the low tidal level. A difference in the observed seabed accretion rate between the transitional intermonsoon period and the succeeding southwest monsoon period was attributed to the direction of the wave energy flux; offshore sediments seem to have been supplied efficiently to the study area by waves during the transitional period. Another potential cause of seabed erosion and accretion during the wet southwest monsoon season was the discharge of water and sediments from local canals associated with intense tropical rainfall; this discharge seems to be linked to land use in the coastal area. The results of this study show the importance of monitoring across‐shore sediment transport for better understanding of coastal erosion processes. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

黄河三角洲滨海湿地健康条件评价   总被引：3，自引：0，他引：3  

安乐生  刘贯群  叶思源  赵全升  丁喜桂  张建伟 《吉林大学学报(地球科学版)》2011,41(4):1157-1165

以黄河三角洲滨海湿地系统为研究对象,基于描述滨海湿地健康条件的4项功能,充分考虑滨海湿地生态地质环境系统的特征及其健康响应因素,建立了黄河三角洲滨海湿地健康条件评价的概念模型和指标体系。以统计监测和遥感数据为基础,采用RS和GIS技术,通过栅格化实现分区评价及其结果的优化整合,探讨了黄河三角洲滨海湿地健康的时空分布规律。结果显示：黄河三角洲滨海湿地现状健康条件处于健康的占14.2%,亚健康的占61.9%,一般病态的占23.9%;近期（2010－2015年）,河口三角洲湿地生境质量会逐步改善,向健康方向发展,而北部和南部部分滩涂区及神仙沟流路等局部地区在自然和人为因素的共同作用下,环境质量会有一定的降低;影响黄河三角洲滨海湿地健康条件的主要因素是全球气候变化背景下的区域水循环关键过程及其时空变化、湿地开发等人类负面干扰和黄河下游生态调度。应继续加大黄河下游生态调度的力度、积极实施生态修复工程,以促进黄河三角洲滨海湿地持续健康发展。  相似文献