感潮河段盐度和缺氧水体时空分布规律研究

感潮河段水体的物质输运规律及其时空分布不仅受径流、潮汐动力的双重影响,还受水闸调度等人类活动的影响.针对水闸调度影响下感潮河段复杂的水动力学及其伴随的物质输运过程,提出一种新的算盘式网格结构,建立了水动力学和物质输送的三维数学模型,考察了在径流、潮汐及水闸调度综合作用下,感潮河段水流密度分层的特点,并对水体中溶解氧和盐度的时空分布规律及其影响因素进行研究.结果发现,数值模拟计算结果与观测值吻合良好,表明所建立的三维数值模型可以很好地预测感潮河段的水流运动和物质输运规律.研究表明,感潮河段的缺氧水体首先出现在盐水楔的前端,在盐-淡水分层强度、盐水停留时间及水闸调度的综合作用下,出现溶解氧浓度持续降低的趋势,并导致缺氧水体范围从河口上游向下游扩展,随水闸的放流缺氧水体被冲刷的现象.     

上海滩涂春季鸻形目鸟类群落及围垦后生境选择

上海市位于长江口，拥有大量可开发的滩涂资源，但是由于不合理的开发方式，滩涂景观和生物群落发生改变。在2004年春季，鸻形目鸟类迁徙中转停留时，实地调查位于上海东部沿岸的10个调查点，研究滩涂生境指标与鸻形目鸟类群落关系。此次观察到的鸻形目鸟类有13种，优势种有尖尾滨鹬和黑腹滨鹬，而20年前的类似调查则观察到23种，优势种为黑腹滨鹬、细嘴滨鹬和红颈滨鹬。通过分析滩涂结构、植被分布与鸻形目鸟类群落之间的关系发现鸻形目鸟类对生境选择中，滩涂结构完整度、藨草带和光滩带的宽度、周边景观的多样性、人为干扰程度都是影响鸻形目鸟类栖息地选择的关键因子。最后，分析了鸻形目鸟类群落与栖息地景观的关系，并就如何改善围垦堤内的生态环境提出一些建议。     

基于灰度形态学和小波变换的淤泥质潮滩水边线提取

平坦的海岸带淤泥质潮滩水边线是模糊的水陆边界，在遥感图像上呈现复杂的边缘，特征获得连续、准确的水边线轮廓是水边线自动提取过程中的难点之一。以长江口崇明东滩为例，选取两景有代表性的Landsat TM影像，采用灰度形态学方法对图像进行预处理，然后采用小波模极大值法获取不同尺度下的水边线轮廓，解决了高细节区边缘的破碎问题，实现了淤泥质海岸带潮滩模糊边界的水边线自动提取。     

城市防洪的一种方法—纳潮

本文介绍一种城市防洪的方法－纳潮。即以合理的调度运行，充分利用圩区的调蓄能力，降低风暴潮引起的高潮位，用以应付超标准风暴潮。通过纳潮效果与纳潮闸位置，调蓄面积，操作方式等因素的关系分析，表明纳潮是一种可行且有效的方法。本文阐述的基本规律，为工程设计、运行操作提供参考依据。     

Effect of weirs on sediment deposition in Louisiana coastal marshes

Sediment deposition both inside and outside of fixed-crest weirs was measured for fresh/intermediate, brackish, and saline marsh areas in coastal Louisiana, USA. Sediment traps, collected on a weekly basis, were used to monitor short-term changes in sediment deposition. Feldspar marker horizons were used to measure cumulative marsh accretion during the 16-week monitoring period. Results show that for most sites less sediment is deposited in marsh behind weirs than at the control sites outside the weirs. Patterns at each site are consistent throughout the 16 monitoring periods. At only one site was no significant difference found. Streamside areas both inside and outside the weirs were found to have higher rates of sediment deposition than backmarsh areas. At both marsh locations, sediment deposition rates were higher outside the weirs than inside. More sediment was deposited in saline marshes than in brackish or fresh/intermediate areas. The vertical accretion data shows that marshes in most areas are accreting sufficiently rapidly to keep pace with local rates of sea-level rise, except for two areas, both of which are inside weirs.     

模拟SO42-沉降对闽江河口潮汐淡水湿地温室气体排放通量的影响

为了探究SO₄2-沉降对潮汐淡水湿地温室气体排放通量的影响,在闽江河口短叶茳芏（Cyperus malaccensis）潮汐淡水湿地模拟SO₄2-沉降,采用静态箱法测定样地环境因子与3种温室气体（CH₄、CO₂、N₂O）通量随SO₄2-添加量和不同月份的变化,采用多元逐步回归分析影响温室气体通量的关键因子.结果表明:①各环境因子和3种温室气体通量均具有显著的月际变化. ②添加SO₄2-显著增加了短叶茳芏种群密度和间隙水ρ（SO₄2-）、ρ（NH₄+-N）,但对其他环境因子无显著影响. ③添加SO₄2-显著抑制了CH₄排放,当SO₄2-添加量（以SO₄2--S计,下同）为40和120 kg/（hm2·a）时,CH₄通量分别减少了33.8%、69.9%;CO₂和N₂O通量随SO₄2-添加量的变化不显著,但分别趋于减小和增加,其中,SO₄2-添加量为40和120 kg/（hm2·a）时,CO₂通量分别减少了5.2%、11.8%,N₂O通量则分别增加了98.0%、103.0%. ④相关分析和多元逐步回归分析结果显示,沉积物温度及间隙水ρ（SO₄2-）、ρ（NH₄+-N）、ρ（NO_x--N）（NO_x--N主要包括NO₃--N和NO₂--N）是影响样地3种湿地温室气体排放通量的关键因子. ⑤当SO₄2-添加量为40和120 kg/（hm2·a）时,3种温室气体排放产生的综合温室效应呈减小趋势,分别降低了5.5%和13.5%.研究推断,SO₄2-沉降速率的升高有助于缓解潮汐淡水湿地对全球气候变暖的贡献.      

海洋环境腐蚀模拟试验装置的优化设计与研制

本文介绍了基于GB/T 19746—2005/ISO 11130:1999等材料腐蚀性能试验标准的试验装置设计要求以及试验装置的主要组成。重点是添加了温度控制系统,优化了潮差控制系统,模拟了海洋波浪。本试验装置是一种结构简单、能够较真实模拟海洋环境腐蚀的试验装置。该试验装置研制成功,为研究海洋用材料的腐蚀行为与机理提供重要的技术设备支持。     

Application of cluster analysis to the geochemistry zonation of the estuary waters in the Tinto and Odiel rivers (Huelva,Spain)

The combination of acid water from mines, industrial effluents and sea water plays a determining role in the evolutionary process of the chemical makeup of the water in the estuary of the Tinto and Odiel rivers. This estuary is in the southwest of the Iberian Peninsula and is one of the estuarine systems on the northwest coast of the Gulf of Cádiz. From the statistical treatment of data obtained by analyzing samples of water from this system, which is affected by industrial and mining pollution processes, we can see how the sampling points studied form two large groups depending on whether they receive tidal or fluvial influences. Fluvial input contributes acid water with high concentrations of heavy metal, whereas industrial effluents are responsible for the presence of phosphates, silica and other nutrients. The estuarine system of the Tinto and Odiel Rivers can be divided into three areas – the Tinto estuary, the Odiel estuary and the area of confluence – based on the physical – chemical characteristics of the water.     

辽东海岸带资源的新资料及意义

本文以最新调查资料为依据,在表述辽东淤泥质海岸基本轮廓的基础上,讨论了潮滩生物、土地、潮汐能等资源特征及开发潜力,并提出以潮滩横向分带性为理论依据的人工生态模式。     

Retreat of Halophytes in the Czech Republic: Agricultural, Mining, and Urbanization Effects

As a result of expanding human pressures, the heterogeneity of aformerly diverse landscape has been reduced and the richness ofanimal and plant species has decreased. Some particular standtypes and their species are especially connected withimpoverishment caused by mans activities. Halophyte DentatedMelilot (Melilotus dentata, Fabaceae) is one of suchspecies, which is vanishing apparently as a result of intensiveagriculture, surface mining, and urbanization.The data on its distribution were compiled from herbariumspecimens, literature, and the authors own field observations.The distribution was mapped separately for four periods: up to1900, 1901–1945, 1946–1975, and after 1975.The trend in reduction of localities was documented. At the sametime, their environmental quality was changing as well.Basically, the salt marshes in their original areal extent andtheir former species richness have disappeared. Currentlocalities of M. dentata include poor fragments of the saltmarshes mentioned above and secondary stands, e.g. ruderal placesinside villages, strips along drainage ditches, paths, railwaylines, fields, etc.