海岸湿沙表面风沙传输特征的风洞实验研究

通过湿沙表面风沙传输的风洞实验,研究了湿润海岸风沙流的垂直结构、输沙率随风速与表层湿度的变化规律。输沙测量使用60 cm高直立式积沙仪,湿度（M）为沙面表层1 mm厚的重量湿度值。结果表明,湿沙表面的输沙量和高度呈指数关系。一般,湿度增大,整体输沙率降低,高湿度床面的沙粒有相对更大的比例被传输到更高的位置。比起低湿度（M＜0.587%）沙粒,高湿度（0.587%＜M＜1.448%）沙粒的垂直运动对湿度变化的影响更加敏感,尤其是在跃移层的底部,当M＞1.448%时,输沙率已经很低,小于0.99 g·cm-1·s-1。伴随湿度0.587%和1.448%的过渡,风沙流垂向分布被分为3个不同坡度的区域,曲线坡度反映了沙粒间不同水分存在形式的影响差异。对于跃移沙粒,高湿度表面（M＞1.448%）仅起到了一个传输平台的作用;当表面变干到某种程度（M=0.587%）之前,表面湿度是跃移运动的主要控制因子,然后风速才重新开始影响输沙。     

广东深圳大鹏半岛海岸地貌特征

大鹏半岛位于广东省深圳市东部,海岸地貌类型多样,可分为基岩海岸、堆积海岸和生物海岸3大类型。文章根据野外调查和室内实验分析的结果论述了大鹏半岛海岸地貌类型、分布和成因,并在前人的研究基础上讨论了大鹏半岛海岸地貌演化过程：由于大鹏半岛处在构造隆升区,海岸类型以基岩海岸为主。多处基岩海岸保留了完好的海蚀崖、海蚀平台、海蚀槽穴、海蚀柱等各类典型的海蚀地貌。该半岛的堆积海岸主要发育于岩石岬角间的海湾内,在有河流流入的海湾处形成岬湾沙坝―澙湖海岸,在无河流的海岸处则形成湾顶海滩。半岛中段狭窄的呈哑铃状腰部的东岸,因深入内凹、波浪减弱,有淤泥质海岸发育;红树林发育于淤泥质海岸以及各澙湖内,而半岛周边浅海区有珊瑚群落生长。大鹏半岛以及邻近地区海岸地貌特征和海岸沉积物年代数据显示：1）地质构造与海平面升降是塑造该半岛海岸地貌的主要因素;2）该半岛的海岸地貌是在中全新世早期以后才开始发育的;3）该半岛全新世以来不存在强烈的地壳抬升;4）该半岛海岸中全新世出现过高于现代海平面的高海面。     

Structure and seasonal changes in atmospheric boundary layer on coast of the east Antarctic continent

The temperature, humidity, and vertical distribution of ozone in the Antarctic atmospheric boundary layer（ABL） and their seasonal changes are analyzed, by using the high-resolution profile data obtained during the International Polar Year 2008 to 2009 at Zhongshan Station, to further the understanding of the structure and processes of the ABL. The results show that the fre- quency of the convective boundary layer in the warm season accounts for 84% of its annual occurrence frequency. The frequency of the stable boundary layer in the cold season accounts for 71% of its annual occurrence frequency. A neutral boundary layer ap- pears rarely. The average altitude of the convective boundary layer determined by the parcel method is 600 m; this is 200 to 300 m higher than that over inland Antarctica. The average altitude of the top of the boundary layer determined by the potential tempera- ture gradient and humidity gradient is 1 200 m in the warm season and 1 500 m in the cold season. The vertical structures of ozone and specific humidity in the ABL exhibit obvious seasonal changes. The specific humidity is very high with greater vertical gradi- ent in the warm season and very low with a lesser gradient in the cold season under 2 000 m. The atmospheric ozone in the ABL is consumed by photochemical processes in the warm season, which results in a slight difference in altitude. The sub-highest ozone center is located in the boundary layer, indicating that the ozone transferred from the stratosphere to the troposphere reaches the low boundary layer during October and November in Antarctica.     

河北昌黎翡翠岛海岸沙丘移动的初步观测

采用RTK GPS技术与测量方法,于2006-2008年对中国海岸沙丘主要分布区域之一的河北昌黎黄金海岸翡翠岛的典型海岸新月形沙丘和横向沙脊的移动进行了高精度观测。观测结果表明,翡翠岛海岸沙丘的移动总体呈现出缓慢、向陆、往复式前进的特征,但不同沙丘类型以及沙丘不同部位的移动间存在差异,其中海岸横向沙脊是底部基本稳定下脊顶在夏秋季向海东移、冬春季向陆西移的往复变化中向陆西移,而新月形沙丘则是沙丘的整体陆向位移且移动速度相对较快,主要与风况、沙丘高度与规模及人类活动有关。     

ESTUARINE AND COASTAL SEDIMENTATION PROBLEMS

This keynote lecture addresses engineering sedimentation problems in estuarine and coastal environments and practical solutions of these problems based on the results of field measurements, laboratory scale models and numerical models. The three most basic design rules are: (1) try to understand the physical system based on available field data; perform new field measurements if the existing field data set is not sufficient (do not reduce on the budget for field measurements); (2)try to estimate the morphological effects of engineering works based on simple methods (rules of thumb, simplified models, analogy models, i.e. comparison with similar cases elsewhere); and (3)use detailed models for fine-tuning and determination of uncertainties (sensitivity study trying to find the most influencial parameters). Engineering works should be designed in such a way that side effects (sand trapping, sand starvation, downdrift erosion) are minimum. Furthermore, engineering works should be designed and constructed or built in harmony rather than in conflict with nature. This ‘building with nature‘ approach requires a profound understanding of the sediment transport processes in morphological systems.     

欧洲瓦登海开发对江苏沿海大开发的启示

欧洲瓦登海沿岸潮差大、潮滩地貌体系发育、潮滩宽阔,是世界围海造田历史中的典范之地。瓦登海沿岸在经历大规模围海造地之后,对近岸海洋生态系统的保护取得巨大进展,已经成为世界自然遗产地。瓦登海沿岸与江苏沿海的潮滩环境有很大的相似性,瓦登海的海岸海洋保护的经验,值得江苏沿海开发进程中借鉴,协调江苏沿海开发与海岸生态系统保护的关系,实施基于生态系统保护的海洋空间规划和多目标开发利用,合理地利用潮滩淤涨的自然规律,可为发展江苏沿海经济提供重要科技支撑。     

海岸沙丘近表层粒度对台风的响应

根据“麦德姆”强台风登陆前后福建平潭岛海岸前丘、爬坡沙丘、横向沙丘和海岸沙席等海岸沙丘近表层的粒度数据,分析了台风登陆前后典型海岸沙丘近表层粒径组成与粒度参数的变化,初步总结了海岸沙丘近表层粒度对台风的响应特征。整体而言,平潭岛海岸沙丘在“麦德姆”登陆前后近表层的粒度变化较小,对台风的响应变化不大且基本无等级性的差别,但海岸沙丘不同类型及不同部位的响应程度并不一致,主要是由海岸沙丘沙与海滩沙粒度的相近性及台风过程中大风的非选择性风蚀所致,同时也受到不同类型沙丘的形态和规模等的影响。     

《江苏省海岸滩涂及其利用潜力》书评

正由王建、徐敏等教授编著的《江苏省海岸滩涂及其利用潜力》,作为"十二五"国家重点图书出版规划项目,由海洋出版社出版发行了。看了这本著作,收益匪浅!我国是世界上人均土地面积最少的国家之一。据测算,随着人口的增长和耕地面积的减少,21世纪中期我国将缺乏4-5亿人的生存空间(陈吉余,2000)。海岸滩涂的开发将会为缓解这一矛盾做出贡献。江苏省是我国人均土地面积最小的省份之一,面积只有全国的1.07%,却承载着全国5.7%的人口。为了缓解人多地少的矛盾,江苏省把目光聚焦到海岸滩涂的开发上。江苏省的海岸滩涂占全国海岸滩涂总面积的1/4左右,是海岸滩涂资源最丰富的省份(任镁锷,1985;江苏省农业资源开发局,1999;中国     

Assessment of reservoir sedimentation effect on coastal erosion in the case of Nestos River,Greece

Coastal erosion that is generated by the reduction of the annual sediment yield at river outlets, due to the construction of reservoirs, constitutes one of the main environmental problems in many parts of the world. Nestos is one of the most important boundary rivers, flowing through Bulgaria and Greece, characterized by its great biodiversity. In the Greek part of the river, two reservoirs, the Thisavros Reservoir and the Platanovrysi Reservoir, have already been constructed and started operating in 1997 and 1999, respectively. The present paper constitutes the first attempt where the assessment of reservoir sedimentation effect on the coastal erosion for the case of the Nestos River delta and the adjacent shorelines is addressed in detail, through mathematical modeling, modem remote sensing techniques and field surveying. It is found that the construction and operation of the considered reservoirs have caused a dramatic decrease （about 83%） in the sediments supplied directly to the basin outlet and indirectly to the neighbouring coast and that this fact has almost inversed the erosion/accretion balance in the deltaic as well as the adjacent shorelines. Before the construction of the reservoirs, accretion predominated erosion by 25.36%, while just within five years after the construction of the reservoirs, erosion predominates accretion by 21.26%.     

苏沪浙闽海岸互花米草盐沼的环境-生态动力过程研究进展

互花米草在其原产地具有生态重要性,然而引入我国并在江苏、上海、浙江、福建海岸广布之后却引发了争议。本文通过相关数据、资料的集成分析,试图对互花米草引种的环境和生态效应作出综合评述,并提出今后的研究方向和科学问题。在本区域,互花米草盐沼具有减小水流底部切应力、促进悬沙沉降、提高沉积速率的作用;现场调查和分析结果表明,互花米草盐沼初级生产高,为底栖动物提供了栖息地,本地盐沼的部分大型、小型和微型底栖动物得以迁入互花米草盐沼,形成了新的生态系统。在纬度地带性和海岸类型等不同背景因素影响下,上述环境一生态变化具有明显的地域性差异：杭州湾以北,全新世基底位置高,潮间带宽度大、坡度小,互花米草盐沼只占据潮间带的较小部分,在海岸防护和生态系统功能上主要起正面作用;杭州湾以南,全新世基底高程低,潮间带宽度小,潮滩主要形成于海湾之内,互花米草的扩展挤占了潮间带其他生物的生存空间,因而有生态上的负面作用。在沿海开发和海岸带管理中,互花米草效应的地域性差异应予以充分考虑。此外,为了预测互花米草盐沼的未来演化问题,除继续进行现场观测外,还要建立以海陆耦合、环境。生态动力过程耦合为特征的互花米草盐沼生态系统动力学模型。