北部湾三维潮流场数值研究(英文)

本文对北部湾三维潮波进行了数值研究,并将所得结果与现有观测资料作了比较。通过比较发现两者相当一致。文中还绘制了M_2和K_1分潮的同潮图,并对其作了讨论。可以断定,北部湾的日潮优势是由日潮共振所引起的。M_2和K_1分潮流的水平分布表明,强流区位于它们各自的蜕化无潮点附近。还讨论了分潮流的铅直结构,可以看出这种结构十分接近实际分潮流场的特征。     

Palynological records of Holocene monsoon change from the Gulf of Tonkin (Beibuwan), northwestern South China Sea

Palynological records in cores C4 and B106 from the Gulf of Tonkin reveal signals of paleo-monsoon and paleoenvironmental change during the late Pleistocene and Holocene. Before ∼ 13.4 cal kyr BP, the Gulf of Tonkin was exposed to the atmosphere and covered by grassland. Starting at ∼ 11.7 cal kyr BP, the Gulf of Tonkin was inundated by brackish water, indicated by the appearance of the brackish algae Cleistosphaeridium, Sentusidinium and Spiniferites, a decrease of herb content, and an increase of Pinus. After Hainan Island was completely separated from the Leizhou Peninsula by Qiongzhou Strait at ∼ 8.5 cal kyr BP, a continuous marine sedimentary environment was found. The current patterns were similar to those of the present, with a general trend of current homogenization reflected by gradually decreasing quantities of Quercus pollen and a narrowing gap between the palynological concentrations of the southern and northern parts of the region. The data suggest that three short periods of strengthened winter monsoons and currents were centered at ∼ 6.0 cal kyr BP, ∼ 2.7 cal kyr BP and ∼ 0.2 cal kyr BP and that two short periods of strengthened summer monsoons and currents were centered at ∼ 7.5 cal kyr BP and ∼ 3.4 cal kyr BP.     

Fieldwork and Tropicality in French Indochina: Reflections on Pierre Gourou's Les Paysans Du Delta Tonkinois, 1936

This paper examines the fieldwork undertaken by the distinguished French geographer Pierre Gourou (1900–99) in the Tonkin Delta (Red River Delta) of northern Vietnam in the 1920s and 1930s, and his wider configuration of “the tropical world” as a distinct space of knowledge and radical otherness. Gourou's fieldwork endeavours in French Indochina are interpreted in the light of recent work on “tropicality”: the idea that “the tropics” need to be understood as a western cultural construction and colonising discourse that essentialised the hot, wet regions of the world, and exalted the temperate world over its tropical counterpart. The paper focuses on Gourou's monumental 1936 study Les paysans du delta tonkinois, étude de géographie humaine. It is argued that in this study, and his later comparative work on the tropics, Gourou elaborated a distinct geographical variant of tropicality, but one that, ultimately, reinforced the essentialist logic and momentum of this discourse. Particular attention is paid to the geographical ideas, fieldwork techniques and discursive strategies that Gourou used in his 1936 study, and the French colonial context in which he worked. The article shows how Gourou appealed to western reason and science as tools of study, identified overpopulation as the key problem facing the Tonkin Delta, and suggested that colonial practices of modernisation had a limited place and ineffectual role in the rice plains of the region.     

北部湾的环流和水团对季节性强迫的响应

In the past 20 a, the gulf-scale circulation in the Beibu Gulf has been commonly accepted to be driven by a wind stress or density gradient. However, using three sensitive experiments based on a three-dimensional baroclinic model that was verified by observations, the formation mechanisms were revealed： the circula- tion in the northern Beibu Gulf was triggered by the monsoon wind throughout a year; whereas the southern gulf circulation was driven by the monsoon wind and South China Sea （SCS） circulation in winter and sum- mer, respectively. The force of heat flux and tidal harmonics had a strong effect on the circulation strength and range, as well as the local circulation structures, but these factors did not influence the major circulation structure in the Beibu Gulf. On the other hand, the Beibu Gulf Cold Water Mass （BGCWM） would disappear without the force of heat flux because the seasonal thermocline layer was generated by the input of heat so that the vertical mixing between the upper hot water and lower cold water was blocked. In addition, the wind-induced cyclonic gyre in the northern gulf was favorable to the existence of the BGCWM. However, the coverage area of the BGCWM was increased slightly without the force of the tidal harmonics. When the model was driven by the monthly averaged surface forcing, the circulation structure was changed to some extent, and the coverage area of the BGCWM almost extended outwards 100%, implying the circulation and water mass in the Beibu Gulf had strong responses to the temporal resolution of the surface forces.     

The new institutional arrangements for fisheries management in Beibu Gulf

China and Vietnam have recently signed two bilateral agreements to deal with maritime issues in Beibu Gulf. One is the maritime boundary delimitation agreement, and the other the fisheries agreement. The two parties have also formulated a supplementary protocol to the latter agreement. All of them have entered into force on 30 June 2004. This article introduces the new arrangements for fisheries management initiated by the two countries, focusing especially on the Joint Fishery Committee established by the two parties, the contracting waters covered by the fisheries agreement, and the conservation and management measures for the Gulf's fisheries. The challenges likely confronted by China after this institutional change takes place are analyzed. A brief comparison is drawn among the three effectual fisheries agreements signed by China, respectively, with Japan, South Korea and Vietnam. Finally, as for the future of fisheries management in the Gulf some recommendations are made.     

Mapping ethnic diversity in highland Northern Vietnam

In this paper we initially present a critical review of a range of ethnological maps produced over the last 130 years for highland northern Vietnam. In particular we illustrate the many difficulties faced when trying to represent mosaics of ethnic highland minority groups on two dimensional maps. Such historical maps included no attempts to bring topographic details into the picture, an idea that would have been virtually impossible anyway, given the cartographic technologies at the time. Yet by not including such details or not representing them clearly, a partial image of these populations has been created that, over time, has become a standardised representation. Therefore, as a more systematic approach to the analysis of these highland minority groups, we present recent attempts to create more functional maps and models for the northern Vietnam province of Lao Cai, using modern cartographic techniques and geographic information systems. Utilising tools such as digital cartography and digital elevation models a wealth of information can be gained which has the potential, amongst other possible uses, to allow for a greater understanding and sensitivity regarding ethnic minority groups in Northern Vietnam, and their use of the local environment. This revised version was published online in July 2006 with corrections to the Cover Date.     

北部湾潮波数值研究

利用普林斯顿海洋模式(POM08)建立了北部湾及其临近海区潮汐潮流数值模式,模拟了K1,O1,M2和S2这4个主要分潮,分析了模拟的潮汐和潮流分布特征,从潮波能量的角度讨论了琼州海峡对北部湾潮波系统的影响,并给出北部湾潮能的耗散情况。研究表明,北部湾是典型的全日潮海区,K1和O1分潮在南部湾口形成半个旋转潮波系统,无潮点位于越南顺安附近岸边。琼州海峡中的欧拉潮汐余流为西向流,潮余流造成的水通量约为0.034×106m3/s;余流出海峡西口后,先折向北,然后转向南流出湾外。研究海区中两个强潮流区分别位于琼州海峡和海南岛的西侧,同时这也是两个潮能的高耗散区。北部湾的潮能自南部湾口由外海传入,通过西口涌入琼州海峡,到达海峡东口时日潮波的能量已基本耗散殆尽,在海峡内耗散的4个分潮的潮能约为3.33 GW,相当于北部湾潮能耗散量的35%左右。数值试验表明,琼州海峡作为潮能耗散的重要海区,其存在对于北部湾潮波系统的形成具有较大影响。计算了底边界潮能耗散,结果表明在北部湾和琼州海峡,底边界耗散的潮能分别占该海区总耗散的83%和80%。     

北部湾东北部2000年以来高分辨率粘土矿物记录及古环境意义

北部湾东北部 GC19-28 孔260BC~1480A.D. 粘土矿物学的高分辨率（平均分辨率为15年）分析表明,该孔的粘土矿物主要由蒙脱石（50%~61%）组成,含中等含量的伊利石（13%~18%）、高岭石（13%~18%）和绿泥石（11%~16%）,在该时间序列上蒙脱石与其他3种粘土矿物变化趋势基本相反。物源区分析显示,GC19-28 孔粘土矿物中的蒙脱石主要由红河提供,伊利石、高岭石和绿泥石主要来源于珠江。该孔高岭石/蒙脱石比值可以反映华南珠江流域季风降雨变化,比值增加表明珠江流域降雨增强;反之亦然。研究结果发现,GC19-28 孔的4种粘土矿物整体表现2个阶段性变化：1）260BC~1200A.D.,4种粘土矿物的相对含量基本保持不变,高岭石/蒙脱石比值同样保持不变;2）从 1200~1480A.D.,蒙脱石相对含量逐渐降低,伊利石、高岭石和绿泥石相对含量逐渐增加,高岭石/蒙脱石比值开始增加。结合贵州董哥洞石笋、广东湖光岩、西沙东岛湖泊沉积物和西太平洋暖池区海表古温度等高分辨率地质记录,推断华南珠江流域由中世纪暖期向小冰期转换过程中,降雨逐渐增加。