唐海湿地现状与保护对策

<正>1.湿地现状唐海湿地的全称是唐海湿地和鸟类自然保护区,于2005年9月经省政府批准,列入省级自然保护区,位于唐海县西南部。按照《湿地公约》对湿地类型的划分,唐海湿地拥有海洋海岸湿地、内陆湿地和人工湿地三大类中的若干种,湿地类型呈现出从内陆向海洋过渡的性质,属复合型湿地。唐海湿地由潮间带滩涂、海滨微咸及咸水沼泽、鱼     

对淮河湿地与防洪关系的思考

湿地与森林、海洋一起并称为地球的三大生态系统.国际<湿地公约>对湿地的定义是:天然、人工、长久或暂时性的沼泽地、泥炭地或水域地带,静止或流动的淡水、半咸水、咸水体,包括低潮时水深不超过6米的水域.定义包括了海岸地带的珊瑚滩和海草床以及滩涂、红树林、河口、河流、淡水沼泽、沼泽森林、湖泊等.     

构建湿地修复制度体系刻不容缓

<正>湿地与森林、海洋并称为地球三大生态系统,具有保持水源、净化水质、调洪蓄水、调节气候、保护生物多样性等多种功能,是人类赖以生存和发展的资源宝库。据估算,我国96%的可利用淡水资源被保存在各类湿地中,1公顷湿地每年可去除1000多公斤氮和130多公斤磷。占陆地总面积8.6%的湿地储存着地球陆地生态系统35%的碳,为20%的已知物种提供了生存环境。湿地因而被誉为"淡水之源""地球之肾""气候调节器"和     

鄱阳湖水文情势过程对典型湿地景观动态变化的影响

以鄱阳湖赣江主支口三角洲湿地1973年~2009年16景遥感影像为基础,利用决策树分类分析近40年来赣江主支口三角洲不同湿地景观类型的组成结构及其演变趋势;并结合遥感影像对应的当天水位,探明水情变化与赣江主支口三角洲湿地景观类型面积之间的动态响应关系。结果表明,近40年来鄱阳湖水位变化以及4种特征水位的淹没天数都是呈现下降的趋势;植被面积呈增长趋势,而水体和裸露洲滩的面积均呈现减少趋势,且裸露洲滩的面积下降速率大于水体面积;水位变化与水体面积拟合关系最优,植被次之,与裸露洲滩拟合最差。研究结果能够进一步阐明鄱阳湖水情变化对典型湿地景观类型空间格局的影响,有助于维持鄱阳湖湿地生态系统结构与功能的稳定。     

谈加快湿地的立法保护

一、湿地的功能(一)湿地的含义。根据《关于特别是作为水禽栖息地的国际重要湿地公约》(简称《湿地公约》)的规定,湿地是指不问其为天然或人工、长久或暂时性的沼泽地、泥炭地或水域地带、静止或流动、淡水、半咸水、咸水体,包括低潮时水深不超过6米的水域。湿地包括多种类型,珊瑚礁、滩涂、红树林、湖泊、河流、河口、沼泽、水库、池塘、水稻田等都属于湿地。它们共同的特点是其表面常年或经常覆盖着水或充满了水,是介于陆地和水体之间的过渡带。     

太湖湿地资源及湿地生态问题与对策

太湖是我国第3大淡水湖泊,地处长江三角洲人口稠密地区,是上海、苏州、无锡等大中城市的水源地,同时也是重要的旅游风景区和水产品生产基地.太湖周边滩地湿地生态系统和水生生态系统遭到严重破坏,湖区资源大大减少,湖体自净能力减弱,蓄洪功能衰减.从可持续发展角度入手,剖析太湖湿地资源开发过程中带来的生态环境问题,包括:湿地面积缩小,自然灾害濒发;环境状况日趋恶化,生产与生活性污染严重;湿地功能日益退化.并在此基础上提出湿地生态系统可持续利用对策,即以现代湿地生态工程技术为指导,全面提高湿地利用的社会、经济、环境综合效益.     

漫滩洪水在西安泾渭滨河湿地水文条件恢复中的作用

利用MODFLOW模型，模拟分析了漫滩洪水对西安泾渭湿地水文条件的影响。研究结果表明：漫滩洪水补给泾渭滨河湿地地下水的作用十分明显，是维持泾渭滨河湿地水文条件的主要水源补给方式；没有漫滩洪水时，渭河河道内水位的涨落对泾渭滨河湿地地下水动态的影响范围很小，仅仅依靠渭河与泾渭滨河湿地的地下水文联系，不足以用来恢复大范围的泾渭滨河湿地。同时，漫滩洪水对距河道300m以外的滨河湿地水文影响最为重要，是其它天然补给途径不能代替的。因此，漫滩洪水是泾渭湿地水文得以维持的主要动力，洪水资源化利用将是恢复该湿地水文条件的     

河道湿地资源利用与保护模式调查监测成果分析与应用

介绍了赣榆县青口河及其上中下游河堤堤防、水质、土壤等情况,从项目的调查监测内容、技术路线、分析方法详细阐述了青口河湿地生态环境保护与持续利用发展模式,分析论证了青口河沿河湿地现有的动植物资源现状与近期入河水质的变化趋势以及入河水质对湿地植被生长环境的影响,提出了湿地保护与可持续利用的优化模式。并对湿地保护提出具体对策与建议。     

不同季节表流湿地对微污染原水的净化效果分析

江苏盐城市在龙冈镇蟒蛇河南岸建设了饮用水源生态净化工程中试系统,以改善饮用水的原水水质。为了探索以挺水、沉水以及浮叶植物构建的表流湿地对微污染原水的水质净化效果,在系统实际运行中,分季节在表流湿地进出口进行了实地采样分析。分析结果表明：① 表流湿地对TP、TN、NH₃-N、COD_Mn及浊度的去除效果较好;对DO有一定影响,使其降低了10.9%;② 不论温度如何变化,湿地系统对TP的去除率基本可保持较高水平;而TN的去除率与温度成正比关系;NH₃-N及COD_Mn去除率在夏、秋季有所波动,但在冬春季,NH₃-N去除效果较好,而COD_Mn的去除效果不明显;DO降低表现为夏秋季大于冬春季;浊度的去除率表现为冬季大于秋季,秋季大于夏季。     

湿地对水质影响的初步研究—以西溪湿地为例

湿地是自然界最重要的生态系统之一,是人类生存的宝贵资源。通过对2011—2014年西溪湿地引水口、内部河道水、湿地出口水3处监测点水质资料的整理分析,初步探讨了西溪湿地对水质产生的影响。证实了湿地对水质的改善作用,但同时该作用也存在明显的时空差异性。     

TIDAL EFFECTS ON GROUNDWATER DYNAMICS IN COASTAL AQUI-FER UNDER DIFFERENT BEACH SLOPES

The tide induced groundwater fluctuation and the seawater intrusion have important effects on hydrogeology and ecology of coastal aquifers.Among previous studies,there were few quantitative evaluations of the joint effects of the beach slope and the tide fluctuation on the groundwater dynamics.In this article,a numerical model is built by using the software FEFLOW with consideration of seawater intrusion,tide effects,density dependent flow and beach sloping effects.The simulation results are validated by laboratory experimental data in literature.More numerical scenarios are designed in a practical scale with different beach slopes.Results show that the groundwater fluctuation decays exponentially with the distance to the beach,i.e.,,and our simulation further shows that the beach slope influence can be expressed in the form of a logarithm function.While for the same location,the amplitude increases logarithmically with the beach angle in the form,where and are related with the horizontal distance()in the form of a logarithm function.The beach slope has no influence on the phase lag,although the latter increases regularly with the distance from the sea.The beach slope effect on the seawater intrusion is investigated through the quantitative relationship among the relative intrusion length(),the relative enhancement of the tide induced seawater intrusion()and the beach angle().It is shown that the tide effects on a milder beach is much greater than on a vertical one,and both λ and κ can be expressed in logarithm functions of.The tidal effect on the flow field in the transition zone for a particular mild beach is also studied,with results showing that the tide induced fluctuation of is similar to the groundwater table fluctuation while shows a distinct variation along both directions.     

珠江磨刀门河口悬沙浓度变化特征分析

根据2011年枯季和2012年洪季在大、中、小潮期间的多点同步现场观测资料,分析研究了磨刀门河口悬沙浓度变化特征。结果表明:磨刀门口悬沙浓度纵向分布呈近岸高,远岸低的趋势;横向分布具有季节性差异,洪季主槽大于滩地,枯季滩地大于主槽;垂向分布洪季主要以斜线型分布为主,枯季主要以抛物线型分布为主。潮周期平均含沙量大潮普遍大于中、小潮;洪、枯季磨刀门口外落潮含沙量普遍大于涨潮含沙量。洪季含沙量混合较为均匀,落潮时含沙量增大,涨潮时含沙量减小,枯季含沙量分层明显,。受波浪潮汐作用,一个周期内有多次明显的再悬浮过程,涨潮时增大,落潮时减小。     

中小洪水引洪淤滩技术试验研究

黄河下游滩区引洪淤滩改土，是滩区治理的重要内容之一。自从滩区立项治理以来，针对中低滩区开展了引洪淤临，淤滩改土和村塘放淤的试验研究工作。本文根据试验和部分滩区引洪放淤经验，提出了在黄河下游利用中小洪水有控制地进行各类引洪放淤规划设计原则和技术措施，以及加快滩区引洪放淤技术的建议。     

波浪作用下缓坡近岸海域沿岸流分布影响因素分析

本文研究了均匀岸坡地形条件下．规则波及不规则波浪作用下缓坡近岸海域沿岸流的分布规律。采用数学模型与物理模型相结合，分析了波浪要素，地形坡度等因素对沿岸流分布的影响。提出了表征沿岸流分布特征参数的经验公式。研究结果表明，缓坡近岸海域，波浪作用下沿岸流的分布主要受到入射波浪波高、入射角度及地形坡度的影响。不规则波浪作用下沿岸流的速度分布相对平缓。     

Performance of a data-driven technique applied to changes in wave height and its effect on beach response

In this study the medium-term response of beach profiles was investigated at two sites: a gently sloping sandy beach and a steeper mixed sand and gravel beach. The former is the Duck site in North Carolina, on the east coast of the USA, which is exposed to Atlantic Ocean swells and storm waves, and the latter is the Milford-on-Sea site at Christchurch Bay, on the south coast of England, which is partially sheltered from Atlantic swells but has a directionally bimodal wave exposure. The data sets comprise detailed bathymetric surveys of beach profiles covering a period of more than 25 years for the Duck site and over 18 years for the Milford-on-Sea site. The structure of the data sets and the data-driven methods are described. Canonical correlation analysis(CCA) was used to find linkages between the wave characteristics and beach profiles. The sensitivity of the linkages was investigated by deploying a wave height threshold to filter out the smaller waves incrementally. The results of the analysis indicate that, for the gently sloping sandy beach, waves of all heights are important to the morphological response. For the mixed sand and gravel beach, filtering the smaller waves improves the statistical fit and it suggests that low-height waves do not play a primary role in the medium-term morphological response, which is primarily driven by the intermittent larger storm waves.     

Lost in space,the sequel: spatial sampling issues with 1‐D PHABSIM

The Physical Habitat Simulation System (PHABSIM) is a popular method for evaluating the habitat value of a stream in terms of a statistic, weighted usable area (WUA). Usually, PHABSIM is used with one‐dimensional (1‐D) hydraulic models, and curves of WUA over discharge are calculated at transects and combined to produce a composite curve. Curves of WUA over discharge are often presented as evidence in proceedings to determine instream flow requirements, so the reliability of these curves is important. Representing a reach of stream with transects introduces ordinary statistical questions: is the sample of transects unbiased, and is it large enough to produce usefully precise estimates? Unfortunately, these questions are seldom considered in PHABSIM studies, even though most PHABSIM studies characterize streams with fewer than 15 transects. Moreover, transect locations usually are selected deliberately, so estimates of WUA will usually be biased. This paper extends an earlier analysis of the uncertainty in composite WUA curves with a much larger set of transect curves, with more analysis of uncertainty in the shape of the WUA curves, and with a different method for simulating errors in estimates of WUA at the transects. The results show that even with larger than usual numbers of transect curves, the precision of composite WUA curves is likely to be poor, especially if there are errors in the transect WUA curves. I also offer suggestions regarding sampling, and for estimating the number of transects that might be needed to achieve a given level of precision in WUA estimates. Copyright © 2009 John Wiley & Sons, Ltd.     

Morphodynamics of sandy beaches under the influence of storm sequences:Current research status and future needs

This paper reviews and discusses the current research status,trends,and future needs in the field of beach morphodynamics under the influence of storm sequences.The paper reviews how the three main research methods,field investigations,numerical modelling,and physical modelling,have been used to study beach morphodynamics during storm sequences.Available quantitative definitions of storm sequences at different sites are presented and discussed.It is shown that the definition of storm sequences is site-specific and requires knowledge of the storm climate,beach characteristics,and the temporal scale of beach recovery.Subsequently,the paper brings together currently available approaches aimed at describing the effect of storm sequences on beach erosion in a general way.The importance of storm chronology and the effects of an extreme storm within a sequence of storms are highlighted.Following that,the more poorly studied aspect of beach recovery in between storms within a sequence is discussed.Three indicators for defining beach recovery,namely the shoreline location,sediment volumes,and the beach state,are identified and compared.Finally,important research needs,including the need for detailed physical modelling,are identified.     

Surface and subsurface water coupled ecological model in a mangrove swamp,Ishigaki Island,Japan

A surface and subsurface water coupled ecological model is presented to describe material cycling in a mangrove area, to which an ecosystem model is applied in order to account for chemical and biological reactions as well as physical processes. In this model, the nutrient transport from the groundwater to the river is estimated by the combined use of field measurements and numerical simulation of subsurface flow. The water movement and temporal variations in nutrient concentration obtained from the numerical simulation show a good agreement with the field observations, indicating that this model is valid for simulating material cycling in a mangrove area. The numerical simulation reveals that the supply of dissolved nutrients from the mangrove to the coastal area during spring tides is about 1.6 to 5.5 times larger than that during neap tides.     

长江口口门湿地的演变分析

通过对长江口口门四大主要湿地的演变分析,认为该区域湿地近30 a来依然延续着淤涨态势。崇明东滩宽度变窄,长度增加,但淤涨速率减小,东南角涨潮槽有将湿地分裂的不利趋势;横沙东滩受促淤围垦影响较大,沙尾继续向东南方向延伸;九段沙和南汇东滩均稳定淤涨。分析表明,为尽可能减少滩涂圈围对湿地生态环境可能带来的不利影响,应深入开展长江口湿地生态环境保护专题研究工作,有效指导滩涂资源的合理开发利用。     

基于BPNN算法的三门峡库区土地利用分类研究

在主成分融合的基础上,利用BPNN算法对三门峡库区土地利用类型进行了分类研究,并对比分析了BPNN算法与MLC算法的分类效果。结果表明:BPNN算法的分类精确度总体上优于MLC算法,采用BPNN算法进行土地利用分类可以取得更好的分类效果;BPNN算法及MLC算法对水体及滩地的分类效果均较好,前者对于沼泽的分类效果要略好于后者,但BPNN算法及MLC算法对其他土地利用类型的分类精确度相比水体、滩地要低,并存在部分错分现象。