海岸沙丘沙运动特征若干问题的研究——以闽江口南岸为例     

陈方  贺辉扬 《中国沙漠》1997,17(4):355-361

在海岸带,沙粒粒径和水分含量是决定沙粒起动风速的最主要因素。闽江口南岸海滩沙的平均粒径为2.0Φ,水分含量多在0.3%~1.0%之间。运用Johnson的经验公式,可计算出海滩沙的起动风速为6~7m/s。这一结果与实际观测值十分吻合。由于海岸环境因素的影响,使得同等条件下海岸带沙粒的起动风速明显大于内陆沙漠沙,而风沙流的输沙率明显小于内陆沙漠沙。海岸带是风速剧变带,在引用陆地气象台站的风速记录分析海岸风况和研究风沙运动规律时,必须对风速进行订正。  相似文献   

鸭绿江口溶解有机碳的研究   总被引：3，自引：2，他引：1  

王江涛  于志刚  张经 《中国海洋大学学报(自然科学版)》1998,(3)

１９９６年５月采样测定鸭绿江口溶解有机碳（ＤＯＣ）的含量,得出分布变化特征,并同其它一些河口的溶解有机碳进行了比较。鸭绿江口表层水溶解有机碳的平均含量为２０８μｍｏｌＣ／Ｌ。在盐度大于１．６的河口区,溶解有机碳的分布主要受海水稀释作用控制;在盐度０～１．６的区域溶解有机碳的浓度随盐度的增加而明显增加。在最大混浊带,ＤＯＣ的浓度最高,表明有颗粒有机碳转化为溶解有机碳。丹东市以上流段,河水中溶解有机碳的含量相对较低,说明由丹东市引入的工业及生活污水对鸭绿江水体中溶解有机碳的含量有一定的影响。  相似文献   

长期稳定河口流路方案评价   总被引：1，自引：0，他引：1  

邢华 《海岸工程》1998,17(4):52-56

分析了长期稳定黄河河口流路的必要性及可行性,阐明了长期稳定流路的思路,对比评价了几条方案,提出了流路安排建议。  相似文献   

Geochemical Changes in Metal and Nutrient Loading at Orplands Farm Managed Retreat Site, Essex, UK (April 1995–1997)     

C.L Macleod  M.D Scrimshaw  R.H.C Emmerson  Y.-H Chang  J.N Lester   《Marine pollution bulletin》1999,38(12):1870-1125

Salt marshes have recently been considered to be a major part of the coastal system and have played a key role in the development of the UK coastal management strategy. Managed Retreat (MR) is a process aimed to restore salt marshes by realignment of the seawalls allowing tidal inundation of low value agricultural land. The resultant marshes are expected to function both as an integral part of the flood defence system and as an ecological conservation area. We report on the effects of salt marsh restoration on metal and nutrient loading of the sediment at the Orplands Farm MR site, Essex, UK. Surficial grab and sediment cores were collected from the two fields that comprise the site. The heavy metals, Cd, Cr, Cu, Hg, Pb, Ni and Zn were analysed to determine changes in anthropogenic inputs to sediments. The major ions, Al, Ca, Fe, K, Mg, Mn and Na were also monitored to identify changes in sediment geochemistry. Analysis of the cored sediments after inundation for Na and Sr demonstrated that penetration of estuarine water had, within 2 yr of exposure, reached an average depth of 20 cm. The study observed that input of heavy metals had occurred to the sediments with the most significant being that of Pb, however increases were also observed for Cr and Cu. However, concentrations of Cd in the MR sediments decreased from 1995 to 1997. For the major metals within both fields it was found that the dominant changes were those of enrichment of marine associated metals, Ca, K, Mg and Na via inputs from tidal inundation. The concentration of Ca in the sediments was further enriched by the deposition of carbonates to the sediments. One field demonstrated a significant loss of Fe from sediments which corresponded to changes in redox potential of the sediments. Differences observed in geochemical profiles between the two fields of the site were attributed to differences in land use prior to flooding.  相似文献   

The restricted buffer capacity of a south Baltic estuary — The oder estuary     

Hinrich Meyer  Reinhard Lampe   《Limnologica》1999,29(3):242

In the river Oder high-waters of the river with high nutrient loads and low biological activity mainly occur during winter. Thus, a remarkable portion of the annual load passes the estuary untransformed. During summer high level of biological activity is observed in the whole estuary, but while more than 10 mol/l dissolved inorganic nitrogen (DIN) is found in the Großes Haff, where the theoretical water-residence time is only 1 month, in the western part of the estuary, where the water-residence time is approximately 3 months, all DIN is transformed into organic matter.The transformed nutrients settle partly as biological products, but they are released again in these shallow waters due to biological and physical degradation, and transported into the Baltic Sea.This behaviour may explain why in the sediments of the Oderhaff with a sedimentation rate of 1 mm/year only 1% of the annual nutrient load of the Oder river can be found.  相似文献   

海岸河口潮流数值模拟的研究与进展   总被引：47，自引：2，他引：45  

李孟国  曹祖德 《海洋学报》1999,21(1):111-125

对海岸河口地区潮流场的数值模拟方法进行了较为系统的归纳总结和评述,对潮流数值模拟的发展趋势进行了分析.  相似文献   

海洋中硼的研究   总被引：2，自引：0，他引：2  

陈国华  王渊 《中国海洋大学学报(自然科学版)》1999,(Z1)

硼是海水中的常量元素,也是自然水体中重要的生物、地质、化学元素。海洋中的硼含量、Ｂ／Ｃｌ 比常用于指示水团,研究大洋环流。海洋粘土中的硼含量作为古盐度的指标。硼也对海洋浮游生物的生长起重要的作用。本文综述了海洋中硼的研究,讨论了海洋中硼的迁移。  相似文献   

邻近城市土壤重金属对九龙江口沉积土壤的影响   总被引：2，自引：0，他引：2  

乔胜英  杨军华  鲍征宇  韩吟文 《海洋地质前沿》2004,20(12):9-13

在研究建立于漳州地区生态地球化学调查基础上,对河口湾沉积物的重金属与人口高度集中的城市地区土壤重金属的分布特征进行了对比,分析了人为活动对河口的影响,结果表明,城区与河口湾表层样品都舍有相对区域基准值较高的Hg、Cd,而且Hg富集系数要远高于Cd的富集系数。分析两种元素来源与迁移方式可知,Hg由于可通过气态形式迁移而对河口影响更大。城区与河口湾样品的重金属进行聚类分析与主因子分析结果表明：城区土壤的As、Zn、Mo、Ni、Cr和Mn主要来自基岩来源。Pb、Se、Cd可以作为人为污染的指示元素,Hg、Sn显示与其他元素具有相对独立的行为。河口湾的元素组合与城区重金属基本相似,但Pb、Cu、Se、Mo、Cd显示出两种因素都有较大影响,可以指示人为影响与基岩源的双重作用。  相似文献   

辽河口沉积物中参与主要生物地化循环的微生物功能基因分析     

宋吉雪  明红霞  石婷婷  苏洁  陈泉睿  金媛  樊景凤 《海洋与湖沼》2021,52(4):904-916

辽河口区域丰富的生物多样性在生物地球化学循环和维持生态系统功能等方面发挥着极其重要的作用。研究辽河口表层沉积物中参与常见地球化学循环的功能基因及其关键影响因子,对揭示和预测辽河口沉积物微生物的功能代谢潜力和受环境变化的影响具有重要意义。应用功能基因芯片(GeoChip 4.0)技术开展微生物功能基因多样性研究。结果表明:在6个沉积物样品中,检测到各类型功能基因48742个,反映了9个微生物介导的关键生物过程。其中,碳循环相关功能基因最多,其次是氮循环和硫循环,而磷循环相关功能基因较少。各站位生物过程相关的功能基因数量和荧光信号值整体呈由远海到近海上升的趋势,即河相区的微生物功能基因较海相区与混合区普遍丰富。碳循环中参与碳固定的基因荧光信号值最高。氮循环中反硝化功能基因荧光信号值最高。总磷与硝酸盐是影响微生物功能基因多样性分布格局的重要因素。该研究有助于了解环境变化对辽河口沉积物生态系统结构和功能的影响,为研究辽河口表层沉积物微生物介导的生物地球化学循环提供科学依据。  相似文献   

Distribution,potential sources and ecological risks of two persistent organic pollutants in the intertidal sediment at the Shuangtaizi Estuary,Bohai Sea of China     

Xiutang Yuan  Xiaolong Yang  Anguo Zhang  Xindong Ma  Hui Gao  Guangshui Na  Humin Zong  Guize Liu  Yongguang Sun 《Marine pollution bulletin》2017,114(1):419-427

Spatial distribution, source apportionment, and potential ecological risks of sixteen polycyclic aromatic hydrocarbons (PAHs) and seven endocrine disrupting compounds (EDCs) in the intertidal sediment at the Shuangtaizi Estuary, Bohai Sea of China were analyzed. Results showed that the total PAH concentrations ranged from 28.79 ng g^? 1 dw to 281.97 ng g^? 1 dw (mean: 115.92 ng g^? 1 dw) and the total EDC concentrations from 0.52 ng g^? 1 dw to 126.73 ng g^? 1 dw (mean: 37.49 ng g^? 1 dw). The distribution pattern for the PAHs was generally different from that of the EDCs possibly due to their distinct sources and n-octanol-/water partition coefficients (K_OW). Qualitative and quantitative analytical results showed that PAH sources were mainly from a mixture of pyrogenic and petrogenic contributions. The higher levels at the southeast of Geligang indicated that the EDC pollutants may have mainly originated from the plastic industry and other chemical plants located along the Liao River. Ecological risk assessment revealed that PAHs exhibited low ecotoxicological effects, whereas EDCs, especially 4-tert-octylphenol and bisphenol A, had high ecological hazard to the estuarine biota.  相似文献