RIVERINE SEDIMENTS AND CHINESE COASTLINE CHANGES     

李从先  张桂甲 《中国地理科学(英文版)》1997,7(3):201-207

I.TI~IC~~RIWiRIrmssoITheupliftingoftheQiughal--Xoing(Tibet)PIateaugeneratedlargeandsediment--ladenrivers,thusthenorthernindianOceanandthewesternPacificOceanreceivedlargevolumeofriverinesedimentswhichconstituteabbothalfofthetotalbinesedimentsintheworld.ChineseoutlinecrossesbobtectonicupliftbeltsandtectonicdepressionbeltS.RiverssuchastheHuanghe(Yellow)myerandChangjiang(Yangtze)caver,etc.~nglargevolumeofSedimentsadnlyrunintOtheseaatthetectonicdepreSSionbelts,andriverssuchastheZhujiang(…  相似文献   

A two‐dimensional analytical solution for groundwater flow in a leaky confined aquifer system near open tidal water     

Zhonghua Tang  Jiu J. Jiao 《水文研究》2001,15(4):573-585

Groundwater in coastal areas is commonly disturbed by tidal fluctuations. A two‐dimensional analytical solution is derived to describe the groundwater fluctuation in a leaky confined aquifer system near open tidal water under the assumption that the groundwater head in the confined aquifer fluctuates in response to sea tide whereas that of the overlying unconfined aquifer remains constant. The analytical solution presented here is an extension of the solution by Sun for two‐dimensional groundwater flow in a confined aquifer and the solution by Jiao and Tang for one‐dimensional groundwater flow in a leaky confined aquifer. The analytical solution is compared with a two‐dimensional finite difference solution. On the basis of the analytical solution, the groundwater head distribution in a leaky confined aquifer in response to tidal boundaries is examined and the influence of leakage on groundwater fluctuation is discussed. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

RESEARCH ON SYSTEM OF FLOOD DISASTER CONTROL AND REDUCTION SUPPORTED BY GIS IN MEDIUM AND SMALL BASINS   总被引：2，自引：0，他引：2  

XUYon－peng  DUJin－kang 《中国地理科学(英文版)》2002,12(1):30-34

Southeast China coastal areas belong to subtropical monsoon climatic zone,thus easily affected by floods resulted from typhoons and rainstorm.Since the areas of river basins are small,rivers flood regulation capacities are low,and therefore flood hazard is grave.In the paper,taking the Yongjiang basin in southeast China as an example,the approaches and methods of geographic information system(GIS) applied to flood disaster control and reduction research on small basin are explred.On GIS help the rainfall-runoff calculation model and the river dchannel flood routing model are developed.And the evaluating flood submerged are and the damage assessment models are built supported by digit elevation models.Lastly the decision support system on GIS supported for flood control in research basin has been set up.This greatly improves flood-proofing decision-making capacities in river basin,and provides valuable information and a mode for flood prevention and reduction in the medium and small basin .Meanwhile,the research indicates that technologies of GIS provide a powerful tool for flood disaster control.  相似文献   

Environmental Impact of Artificial Harbors in Tropic Pacific Oceanic Islands     

XUEChunting RussellHoworth HEChaoxiong 《中国海洋大学学报(英文版)》2004,3(1):99-105

1　Introduction　Oceanicislandsfallintoseveraldifferenttypes .Thecommontypesarevolcanicislands ,atollsandemer gentlimestoneislands (ScottandRotondo ,1 983;Woodroffe ,1 992 ) .Avolcanicislandinthetropicshasfringingor andbarrierreefs .Anatollhasaring shaped…  相似文献   

Holocene Sea Levels and Coastal Change,South-west Viti Levu Island,Fiji     

Kirti K. Lal 《The Australian geographer》2011,42(1):41-51

For the first time, a sediment core spanning the entire Holocene has been analysed from Fiji. The 6 m core was obtained from the floor of an ancient coastal lagoon (palaeolagoon) adjacent to Bourewa, the site of the earliest known human settlement in this island group. The basal sediments, just above bedrock, date from 11 470 cal bp. A major transition occurs around 8000 cal bp where marine influences on palaeolagoon sedimentation increase sharply. Full shallow-water marine conditions are attained around 4630 cal bp and last until 3480 cal bp after which there is a regressive phase. The results agree with the area-specific predictions of sea level in the ICE-4G model, particularly in the timing of the highstand. In addition, the results support the ideas (a) that early human colonisation of Fiji occurred during the late Holocene regression, (b) that the first inhabitants of Bourewa utilised both nearshore marine (reefal) and brackish lagoon food sources, and (c) that the abrupt human abandonment of the area around 2500 cal bp could have been prompted by a reduction in these resources driven largely by sea-level fall.  相似文献   

The research of sea-land breeze (SLB) on the west coast of Bohai Bay based on field observation     

Wei Gu  LaiYin Zhu  WeiJia Cui  Ning Li  JianOu Cong  YingJun Xu  ShuQing Huang  HaiYang Yu  LanTao Li 《寒旱区科学》2011,3(3):0264-0273

Four automatic meteorological stations were set up in a line from beach to inland perpendicular to the west coast of Bohai Bay. Wind direction and velocity at altitudes of 2 m, 4 m and 12 m were surveyed with 10 minute intervals. On "Sea-Land Breeze" (SLB) days, the transition from sea breeze to land breeze was very evident in the study area. Direction of sea breeze was basically perpendicular to the coast and mainly from the ENE and E. Duration of sea breeze varied by the stations’ distance to the coastline, and the near-coast wind velocity was larger than that of the inland and decreases as it reaches inland. There was increased development of SLB on sunny days than on overcast days. The term "Climatic Coastal Zone" can be defined for the area influenced by SLB, which reaches more than 74 km inland on a typical SLB day but less than 10 km on a non-typical SLB day.  相似文献   

Wetland conservation and sustainable coastal governance in Japan and England   总被引：1，自引：0，他引：1  

Fletcher S  Kawabe M  Rewhorn S 《Marine pollution bulletin》2011,62(5):956-962

Coastal wetlands present particular challenges for coastal governance and for the implementation of the Ramsar Convention, not least because coastal areas are focal points of human activity and of governance ambiguity. Through the evaluation of Ramsar delivery at both national and local levels in Japan and England, the relationship between Ramsar implementation and coastal governance was examined. In England, Ramsar status is primarily treated as a nature conservation designation which limits the wider opportunities inherent in the designation. In contrast, in Japan, the Ramsar Convention is used as a policy driver at the national level and as a leverage to encourage citizen engagement, economic benefit, and wetland conservation at the local level. It was concluded that through the implementation of the Ramsar Convention in important coastal wetland areas, significant steps can be taken towards delivering integrated approaches to coastal governance.  相似文献   

METEOROLOGICAL TSUNAMIS IN SOUTHERN BRITAIN: AN HISTORICAL REVIEW*     

SIMON K. HASLETT  EDWARD A. BRYANT 《Geographical review》2009,99(2):146-163

ABSTRACT. Meteorological tsunamis, or meteo‐tsunamis, are long‐period waves that possess tsunami characteristics but are meteorological in origin, although they are not storm surges. In this article we investigate the coast of southern Britain‐the English Channel, the Bristol Channel, and the Severn Estuary‐for the occurrence of tsunami‐like waves that, in the absence of associated seismic activity, we recognize as meteo‐tsunamis. The passage of squall lines over the sea apparently generated three of these events, and two seem to have been far‐traveled, long‐period waves from mid‐North Atlantic atmospheric low‐pressure systems. The remaining three wave events appear to have been associated with storms that, among possible explanations, may have induced large‐amplitude standing waves‐such as seiches‐or created long‐period waves through the opposition of onshore gale‐force winds and swells with high ebb tidal current velocities. This coastal hazard has resulted in damage and loss of life and should be considered in future coastal defense strategies and in beachuser risk assessments.  相似文献   

莱州湾东岸陆海相互作用与海岸缓冲区     

杜国云  王庆  孙祝友 《地理研究》2006,25(5):853-864

提出了海岸缓冲区的概念。结合莱州湾东岸晚更新世以来陆海相互作用历史与近期变化,将海岸缓冲区分为古潟湖地貌限制型、开放型和人工海岸型3种基本类型,在横向上划分出3个缓冲带,对海岸缓冲区的结构与功能及缓冲区范围进行了研究。本研究对防范海岸带地质灾害、减轻灾害损失与海岸带资源与环境的可持续发展将起到积极的作用。  相似文献   

中国数字海洋构建基准与关键技术   总被引：11，自引：1，他引：10  

苏奋振  杜云艳  裴相斌  杨晓梅  周成虎 《地球信息科学学报》2006,8(1):12-15,20

地理信息系统(GIS)以其空间数据管理、空间分析和图形图像产品制作能力的强大,在海洋领域展现了巨大的潜力。但由于地理信息系统发展于陆地应用,面对海洋特性,有诸多不足。为此,本文在分析海洋特征的基础上,以中国海岸线为基准,构建中国数字海洋的原型系统。重点讨论了数字海洋的问题和解决办法,分析了以海岸线为基准的数据组织与处理,并探讨了其结构体系与集成方式,逻辑运算与可视化方法。  相似文献