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1.
As part of a collaborative study between the 3rd Institute of Oceanography, Xiamen, and the U. K. Universities of East Anglia
and St. Andrews, a 4-day experiment was conducted on a ridge- and- runnel beach of north Norfolk on the North Sea coast. Detailed
surveys were made of every low water of an area 10m by 30m and electromagnetic current meters were used to measure wave-induced
currents over the ridge and in the runnel. The locations of bedform fields were noted, fluorescent sand was used to follow
the sand movement and, at the end of the experiment, lacquer peels were taken of the top 0.2m of a vertical section through
the ridge- and- runnel.
During the 4 days 0.75m3 of sand per metre width of beach accreted in the runnel and a similar volume was eroded from the upper foreshore. The dominant
shoreward transport, identified qualitatively by the movement of the fluorescent sand, suggests the ridge- and- runnel system
migrated shorewards up the general beach slope of 1o by 2–3m. The wave orbital currents were used to predict the bedforms to be expected over the tidal cycle: an upper phase
plane- bed was predicted for most of the period but vortex and rolling- grain ripples were predicted and observed when the
water level over the ridge was low. As the tide dropped ripples on the ridge were eliminated by swash action but the ripples
in the runnel were protected by the ridge and remained on the beach after the tide dropped.
The observed accretion of the beach in the runnel and on the lee slope of the ridge was used to calculate that a net average
shoreward transport of 0.11g/cm·s−1 occurred over the ridge crest during the period it was underwater. The current meter measurements of the wave orbital currents
and the mean currents over the ridge crest were used with the wave- current interaction model of Grant and Madsen (1982),
ripple dimensions defined by Nielsen (1981), and resuspension coefficient of Vincent and Green (1990), to compute bedload
sand transport rates from the equations of Madsen and Grant (1976), Sleath (1978), and Vincent et al. (1981), and also the
suspended sand transport rates. The results from one of these bedload equations (Madsen and Grant, 1976) compared well with
the observed net transport. The calculated suspended load transport rates (due to steady currents alone) were a factor of
5 too great, and were also several orders of magnitude greater than suspended transport rates measured directly under similar
or more energetic wave and current conditions. 相似文献
2.
WANG Yangang HU Xiaozhong LONG Hongan SONG Weibo 《中国海洋大学学报(英文版)》2007,6(4):387-392
The living morphology and infraciliature of a marine ciliate, Cardiostomatella vermiformis isolated from a sand beach of the Jiaozhou Bay near Qingdao, China, were investigated by live observation, protargol and silver carbonate impregnation methods. Both the morphological and morphometric data largely agree with former records. Based on the data obtained, an improved diagnosis for Cardiostomatella vermiformis is supplied: Large marine Cardiostomatella with cylindrical body shape and several prolonged caudal cilia; cells in vivo about (90–500) μm×(30–120) μm; macronucleus beaded; single contractile vacuole caudally positioned; buccal apparatus conspicuously small, genus typical; three to six postoral kineties; 96-130 somatic kineties. This species is recorded for the first time in China. 相似文献
3.
4.
BASIC FEATURES OF FOREST STEPPE IN THE LOESS PLATEAU OF CHINA 总被引：2，自引：0，他引：2
朱志诚 《中国地理科学(英文版)》1995,5(2):170-174
ＢＡＳＩＣＦＥＡＴＵＲＥＳＯＦＦＯＲＥＳＴＳＴＥＰＰＥＩＮＴＨＥＬＯＥＳＳＰＬＡＴＥＡＵＯＦＣＨＩＮＡ￥ＺｈｕＺｈｉｃｈｅｎｇ（朱志诚）（ＤｅｐａｒｔｍｅｎｔｏｆＢｉｏｌｏｇｙ．ＮｏｒｔｈｗｅｓｔＵｎｉｖｅｒｓｉｔｙ，Ｘｉａｎ７１００６９，ＰＲＣ）Ａ... 相似文献
5.
《中国海洋大学学报(英文版)》2015,(5)
The beach studied in this paper spans a length of 51 km and is one of several long sandy beaches in the southern Bohai Strait. Due to the obstruction of islands in the northeast and the influence of the underwater topography, the wave environment in the offshore area is complex; beach types and sediment transport characteristics vary along different coasts. The coastlines extracted from six aerial photographs in different years were compared to demonstrate the evolving features. Seven typical beach profiles were selected to study the lateral beach variation characteristics. Continuous wind and wave observation data from Beihuangcheng ocean station during 2009 were employed for the hindcast of the local wave environment using a regional spectral wave model. Then the results of the wave hindcast were incorporated into the LITDRIFT model to compute the sediment transport rates and directions along the coasts and analyze the longshore sand movement. The results show that the coastline evolution of sand beaches in the southern Bohai Strait has spatial and temporal variations and the coast can be divided into four typical regions. Region(I), the north coast of Qimudao, is a slightly eroded and dissipative beach with a large sediment transport rate; Region(II), the southwest coast of Gangluan Port, is a slightly deposited and dissipative beach with moderate sediment transport rate; Region(III), in the central area, is a beach that is gradually transformed from a slightly eroded dissipative beach to a moderately or slightly strong eroded bar-trough beach from west to east with a relatively moderate sediment transport rate. Region(IV), on the east coast, is a strongly eroded and reflective beach with a weak sediment transport rate. The wave conditions exhibit an increasing trend from west to east in the offshore area. The distribution of the wave-induced current inside the wave breaking region and the littoral sediment transport in the nearshore region exhibit a gradual weakening tendency from west to east, which is opposite to the trend of the wave conditions outside the breaking region. The presence of submerged shoal(Dengzhou Shoal), deep trough(Dengzhou Channel), islands and irregular topography influnces the wave climate, beach types, wave-induced current features, littoral sediment transport trends and coastline evolution patterns in the southern Bohai Strait. Human activities, such as the sand exploitation of Dengzhou Shoal and other coastal engineering projects, also influence the beach morphology and coastline evolution. 相似文献
6.
辽东湾海岸类型及其分布受区域地质构造控制。海岸类型可分为:港湾型基岩海岸、岛礁型基岩海岸、岬湾型沙质海岸、平原型淤泥质海岸等4类;潮间带地貌分为海滩、潮滩、岩滩3类;水下堆积地貌主要有水下三角洲及潮下浅滩。受河流输沙影响,淤积先从河口开始,然后向外围扩散。在湾顶部,地貌及内、外动力条件利于海岸淤涨,但受滨岸海洋水文条件制约,发展不均衡,可出现局部短时间的侵蚀后退现象。海岸工程可控制海岸的演化过程,滩涂地带引种植物可促进海岸持续淤涨。 相似文献
7.
The headland-bay beach is one of the most common coastal types in the world.Its morphology reflects the changes that occurred during long-term evolution of the sandy coast.Several headland-bay beach models have been proposed to simulate the coastline’s configuration in equilibrium.In this paper,a new elliptical model is proposed,described,and applied.On the east coast of Laizhou Bay in Shandong Province from Longkou Port to Diaolongzui,four typical headland-bay beaches have developed,and four headland-bay beach models are used in this paper to simulate the morphology of these beaches to assess the applicability of each model.The simulation results of the elliptical model verify that it is applicable to the study area.In addition,the elliptical model is easy to use.Through simulation and field investigations,we concluded that most of the coastal segments in this area will remain in an erosion state,and the human activity has a significant impact on the shoreline’s evolution. 相似文献
8.
Acrochaete leptochaete,a species in Chaetophoraceae(Chlorophyta),was observed during our recent laboratory culture of the macroalgae Chaetomorpha that was originally collected from an intertidal pool in Rongcheng,Shandong Province,China.This is the first record of this species in China.Its morphology,taxonomy,and distribution were introduced and discussed in detail.Isolated culture experiments at different temperatures(9-29℃)and light intensities(36-108μmmol/m 2·s)were also carried out.The culture-based observations have extended our knowledge of growth morphology and general biology of the species. 相似文献
9.
在烟台第一海水浴场，利用经纬仪进行2条海滩横剖面形态测量，并在不同地貌单元采集沉积物样品进行粒度分析。测量显示，该海滩仅有小规模沙坝和沟槽体系。后滨上有风成沉积，但滩肩和海岸沙丘发育均不明显。粒度分析结果表明，海滩沉积物以中砂、粗砂为主，杂以砾或细砂，比山东半岛其他海滩沉积物明显要粗。由陆向海沉积物呈带状分布，平均高潮线附近和沙坝迎水坡侵蚀作用均显著。因此认为缺乏沙源供应的基岩岬湾式海岸是导致沙滩地貌发育不典型、海滩侵蚀作用显著的主要原因。 相似文献
10.
伊犁地块可按昭苏-特克斯、婆罗科努南坡-尼勒克、婆罗科努北坡及博尔塔拉-伊林哈比尔尕等断裂,划分为三个构造单元,由南西向北东展布有:伊宁波疏带、婆罗科努波密带和温泉-赛里木波疏带,其构造演化过程是,温泉斯-赛里木、伊犁地块在元古代时期,镶嵌在塔里木地块的西北缘,后来,经历了寒武一中奥陶世早期边缘海盆演化.中奥陶世晚期,温泉-赛里木与伊犁地块裂陷.志留纪末,两地块镶嵌拼贴.晚古生代是断陷-拗陷活动时期.中石炭世是准噶尔地块西南缘伊林哈比尔尕波峰带与温泉-赛里木及婆罗科努构造带镶嵌的主要时期.研究区还划分出三个成矿区带. 相似文献
11.
ANALYSES OF RECENT GEOMORPHIC EVOLUTION OF GARGATHY INLET, EASTERN SHORE OF VIRGINIA, U. S. A. 总被引：1，自引：0，他引：1
Uargathy Inlet is a small natural tidal inlet in the northern region ol the Virginia Darner island chain. It is 100 m wide with a throat cross-sectional area of 384m2 and an average tidal prism of 6.47 x 106 m3. The inside drainage system is 7.8 km long and 2.2km wide. The main channels comprise 5.8% of the area, shallow lagoons 19.8%, and Spartina marshes 74.4% in 1970. Over the period 1851 - 1989 the inlet narrowed and migrated northward while maintaining a weakening downdrift offset. The nearby barrier island coastline's rapid retreat (average rate 4.78m /a, 138 years retreat 660 m) was accompanied by back barrier channel and lagoon filling and a decrease in intertidal water volume which was probably the main reason for the entrance narrowing. The northward migration of the inlet was related to the dredging of the Inside Passage (before 1949) and the breaching of southern Metompkin Island (since 1957) connected with the inlet system. This altered the interior tidal circulation and likely shifted nort 相似文献
12.
A heat budget study on the mechanism of SST variations in the Indian ocean dipole regions 总被引：1，自引：0，他引：1
HU Ruijin LIU Qinyu LI Chongyin 《中国海洋大学学报(英文版)》2005,4(4):334-342
By using a new heat budget equation that is closely related to the sea surface temperature （SST） and a dataset from an ocean general circulation model （MOM2） with 10-a integration （1987-1996）, the relative importance of various processes determining SST variations in two regions of the Indian Ocean is compared. These regions are defined by the Indian Ocean Dipole Index and will be referred to hereafter as the eastern （0^＊-10^＊S, 90^＊-110^＊E） and western regions （10^＊S- 10^＊N, 50^＊-70^＊E）, respectively. It is shown that in each region there is a falling of SST in boreal summer and a rising in most months of other seasons, but the phases are quite different. In the eastern region, maximum cooling rate occurs in July, whereas in the western region it occurs in June with much larger magnitude. Maximum heating rate occurs in November in the eastern region, but in March in the western one. The western region exhibits another peak of increasing rate of SST in October, indicating a typical half-year period. Net surface heat flux and entrainment show roughly the same phases as the time-varying term, but the former has much larger contribution in most of a year, whereas the latter is important in the boreal summer. Horizontal advection, however, shows completely different seasonal variations as compared with any other terms in the heat budget equation. In the eastern region, it has a maximum in June/November and a minimum in March/ September, manifesting a half-year period; in the western region, it reaches the maximum in August and the minimum in November. Further investigation of the horizontal advection indicates that the zonal advection has almost the opposite sign to the meridional advection. In the eastern region, the zonal advection is negative with a peak in August, whereas the meridional one is positive with two peaks in June and October. In the western region, the zonal advection is negative from March to November with two peaks in June and November, whereas the meridional one is positive with one peak in July. Different phases can be clearly seen between the two regions for each component of the horizontal advection. A detailed analysis of the data of 1994, a year identified when the Indian Ocean dipole event happened, indicates that the horizontal advection plays a dominant role in the remarkable cooling of the eastern region, in which zonal and meridional advections have the same sign of anomaly. However, in the western region in 1994 no any specialty was shown as compared with other years, for the SST anomaly is not positive in large part of this region. All these imply that the eastern and western regions may be related in a quite complex way and have many differences in dynamics. Further study is needed. 相似文献
13.
Since the late 1950’s, many Chinese scientists have explored the remains of the Quaternary glaciation in the Qinghai-Xizang
(Tibet) Plateau and its surrounding mountains. In the main, 3–4 glaciations have been recognized. The largest one occurred
in the Late Middle Pleistocene with piedmont glaciers, ice caps and trellis valley glaciers in many high peak regions. But
here is no evidence of a unified ice sheet covering the whole plateau as described by M. Kuhle. Due to the further uplifting
of the Himalayas and Qinghai-Xizang Plateau the climate became progressively driver, diminishing the extension of glaciers
during the Late Pleistocene. The elevation of the snow line during the Last Glaciation was about 4,000 m on the south, east
and northeast edges of the plateau and ascended to 5500 m on the hinder northwest of the plateau. The thermal effect of the
big plateau massif, the sharp increase of aridity from the southeast rim to the northwest inland area and the abrupt decrease
of precipitation during the Ice Age largely account for the distribution of the Quaternary glaciers in the Qinghai-Xizang
Plateau. The neglect of Chinese literature may be one of the causes accounting for M. Kuhle’s misinterpretation on the environment
of the Quaternary glaciations in the Qinghai-Xizang Plateau. 相似文献
14.
近20年来厦门市滩涂养殖时空演变与政策驱动分析 总被引：2，自引：0，他引：2
沿海滩涂是一种重要的湿地资源,也是一种重要的可再生的后备土地资源。在滨海城市,滩涂养殖的时空演变过程能敏感反映产业经济发展、生态环境变化及政策导向三个因素之间的博弈关系。对此,利用1986、1989、1993、1997年TM遥感影像和2001、2003年ETM+遥感影像以及2004年SPOT遥感影像,用单一土地利用动态度、景观破碎度和重心迁移模型,对近20年来厦门市滩涂养殖的时空演变过程进行了分析。结果表明:滩涂养殖面积从1986年的2661.85hm2持续增长到2003年的9776.45hm2,增长了2.67倍,2004年则开始下降到9510.98hm2,在此期间面积的年均变化率从1986～1989年的19.80%逐渐下降到2003～2004年的-2.72%;1986～2004年养殖区的景观破碎度均小于0.00080;空间分布重心总体上向东北方向迁移。对政策驱动机制的初步研究表明,养殖区的这种变化过程与当地的一系列政策措施存在着宏观响应关系。 相似文献
15.
使用2009-01-01～2017-03-30内蒙古地震台网和邻省台网记录的大兴安岭北段地区593个天然地震的3 848条P波到时数据，应用VELEST方法反演大兴安岭北段地壳一维P波速度模型、台站走时校正值和重新定位结果。联合反演获得的台站走时校正值反映了地壳速度的横向不均匀性及台站下方波速异常，大兴安岭北段东南侧速度高于西北侧；重新定位结果中，震中位置在空间上更加收敛；震源深度剖面图显示，大兴安岭北段西北侧震源深度较浅，东南侧较深，大兴安岭山脊区域震源深度分布下限较深。 相似文献
16.
As for the formation of the submerged trough of Maxwell Bay and the external agent geomorphic-phenomena of Fildes Peninsula, we can use glaciated theory to explain them. Moreover, based on a large number of field investigation by foreign colleagues and the authors, we can consider that the last glaciated ice-stream which had a great effect on current periglacio-landform distribution, mainly flowed along the direction from northwest to southeast. The periglacio-geomorphic distribution of the peninsula has a deep brand of glaciated history. Three kinds of different profile assemblage features show that the periglacial landform have an internal relationship in genesis. They also show a difference between stoss and leeward slopes by glaciated effect. 相似文献
17.
There are several well-established methods for obtaining beach profiles, and more accurate and precise high-tech methods are emerging. Traditional low-cost methods requiring minimal user skill or training are still popular among professionals, scientists, and coastal zone management practitioners. Simple methods are being developed with a primary focus on sand and gravel beaches. This paper describes a simple, low-cost, manual field method for measuring profiles of beaches, which is particularly suitable for muddy shores. The equipment is a type of flexible U-tube manometer that uses liquid columns in vertical tubes to measure differences in elevation; the supporting frame is constructed from wooden poles with base disks, which hold measuring scales and a PVC tube. The structure was trialed on a mudflat characterized by a 20~0-cm-thick surface layer of silt and clay, located at the Kutubdia Island, Bangladesh. The study results are discussed with notes on the method＇s applicability, advantages and limitations, and several optional modifications for different scenarios for routine profiling of muddy shores. The equipment can be used by one person or two people, and the accuracy of the method is comparable to those in other methods. The equipment can also be used on sandy or gravel beaches. 相似文献
18.
茂名市滨海地区旅游资源分类及综合评价 总被引：1，自引：0，他引：1
林东年 《广东海洋大学学报》2005,25(2):11-15
依据国家标准对茂名滨海地区有旅游开发价值的旅游资源进行了分类,将其共划分为8主类、21亚类、40基本类型。评价结果表明,列为优良级旅游资源、普通级旅游资源各有4处。根据茂名滨海地区旅游资源具有浓厚的地方特色、资源丰富且品位高、开发价值大、各种类型旅游资源组合优势突出、旅游资源普遍保护好等优点,提出了8项海洋文化旅游项目,以对滨海旅游资源进行深层次的开发,逐步把茂名滨海地区建成滨海旅游资源开发示范区,带动全省滨海旅游业向高层次、多内容、具有海洋特色的方向发展。 相似文献
19.
20.
以山东省作为研究区域，利用分辨率为100m的2005年、2008年、2010年和2013年土地利用遥感解译数据和统计年鉴资料，结合ArcGIS空间分析和数理统计等方法，分析山东省土地利用时空变化，通过多元回归模型揭示土地利用变化与经济社会驱动因素之间的变量关系。研究表明，山东省耕地面积从1036.55×104hm2到1024.34×104hm2不断减少，建设用地面积从214.05×104hm2到275.75×104hm2不断增加并且大量占用耕地、林地、草地。耕地向山东省的东部丘陵地区和西部、北部地势低洼平坦地区转移，建设用地向东南部和西北低洼平坦地区转移较多。2008—2010年综合土地利用动态度最为强烈，分别是2005—2008年和2010—2013年的9倍和12倍。人口增长、经济发展、产业结构改变等因素与土地利用变化的相关性较强，这些因素在土地利用类型变化中发挥着重要的作用。 相似文献