福建宁德三都澳的沉降与冲淤探讨     

陈世亮 《福建地质》2008,27(4):409-413

宁德三都澳位于福建省东部沿海,口小腹大水深,为中国乃至世界罕见天然良港,阐述全新世以来,三都澳的地壳沉降规律、新构造运动特征,分析三都澳在全新世（1万年）以来,以及全新世晚期（三千多年）来,澳内沉降速率,淤积物等情况,认为三都澳成为世界性良港原因,是地壳沉降作用整体大于澳内淤积物。  相似文献   

位山灌区西输沙渠改造探索     

薛桂先 《地下水》2008,30(3):125-126

针对位山引黄灌区西输沙渠泥沙淤积严重,堤外弃土征地困难,清淤弃土很难解决的问题,提出缩窄横断面改造方案,加大水流速度,增加西输沙渠的挟沙能力。  相似文献   

A Novel Method for Real-Time Monitoring of Channel Siltation Based on Bistatic Scattering Theory     

侯朋  许文海  王俊生  李瑛 《中国海洋工程》2010,24(1):105-115

Monitoring the thickness changes of channel siltation is paramount in safeguarding navigation and guiding dredging.This paper presents a novel method for realizing the field monitoring of channel siltation in real time.The method is based on the bistatic scattering theory and concerned more with the receiving and processing of multipath signal at high-frequency and small grazing angle.By use of the multipath propagation structure of underwater acoustic channel,the method obtains the silt thickness by calculating the relative time delay of acoustic signals between the direct and the shortest bottom reflected paths.Bistatic transducer pairs are employed to transmit and receive the acoustic signals,and the GPS time synchronization technology is introduced to synchronize the transmitter and receiver.The WRELAX (Weighted Fourier transform and RELAX) algorithm is used to obtain the high resolution estimation of multipath time delay.To examine the feasibility of the presented method and the accuracy and precision of the developed system,a series of sea trials are conducted in the southwest coast area of Dalian City,north of the Yellow Sea.The experimental results are compared with that using high-resolution dual echo sounder HydroBoxTM,and the uncertainty is smaller than ±0.06 m.Compared with the existing means for measuring the silt thickness,the present method is innovative,and the system is stable,efficient and provides a better real-time performance.It especially suits monitoring the narrow channel with rapid changes of siltation.  相似文献   

历史时期黄河下游的淤积、决口改道及其与人类活动的关系   总被引：9，自引：1，他引：9  

陈志清 《地理科学进展》2001,20(1):44-50

黄河是世界闻名的多沙性河流,历史时期就不断淤积、决口改道,且淤积速度不断加快,决口改道的频率也在不断增加。黄河下游地上河的发展和演变是自然因素和人类活动综合作用的结果。历史时期流域内人口的增加、耕作方式的改变及其对植被造成的破坏都对中游地区侵蚀的加剧、来沙的增加,以及下游地区河道的淤积及决口改道的发生带来不同程度的影响。  相似文献   

黄河万家寨水库库区冲淤变化分析     

齐斌  熊运阜 《水文》2001,21(3):45-47

介绍了黄河万家寨水库运行及库区水文泥沙动态监测的基本情况，并对水库容淤积、库区淤积物分布、泥沙组成及水库淤积形态等方面的问题进行了分析探讨。  相似文献   

碧口水库坝前淤积状况分析     

何录合 《水文科技信息》1997,14(4):16-21

碧口水库泥沙在库内大量淤积，坝前淤积已 高于泄水建筑物进口高程，泄水建筑物门前形成的冲刷漏斗很小，不足以容纳正常来水所挟带来的泥沙。  相似文献   

甘肃省炳灵寺大寺沟淤积及黄河水倒灌问题初探     

李文军 《中国地质灾害与防治学报》1997,8(3):91-93

  相似文献   

九龙江入海口重矿物的迁移及其对厦门西港南部淤积的影响     

陈华胄  郭允谋  杨顺良 《热带海洋学报》1994,(1)

通过对九龙江入海水道、厦门西港南部重矿物组合规律、物质来源的研究，结果表明，九龙江细砂级以上颗粒朝外海方向迁移，没有进入厦门西港。厦门西港鳗尾沙淤积区的沉积物为孤丘海蚀残积物及粉砂质泥。内土尾淤积区沉积物为凝聚成小球的粘土及黑云母，它来自九龙江悬沙与海岸工程抛入的泥沙。  相似文献   

淇澳岛东南抛泥区对珠海九洲港航道的影响   总被引：5，自引：0，他引：5  

尹毅  贾桂华 《海洋与湖沼》1992,23(3):260-263

  相似文献   

Study of back-silting strength in the north passage channel of Changjiang Estuary     

MA Gangfeng  LIU Shuguang  QI Dingman 《海洋学报(英文版)》2007,26(2):56-64

Temporal and spatial variations of the back-silting strength in the north passage channel of Changjiang Estuary are investigated using the empirical orthogonal function (EOF) method, with the aim to determine the imposed processes and time-scales. Data on back-silting quantity in every dredging unit of the channel have been collected since March 2000, predominantly once 15 d. The EOF analysis of the back-silting strength reveals two significant modes, which totally explain 58.33% of the overall variance, and the corresponding processes and time-scales. The first EOF mode shows a clear annual cycle which is determined by the riverine water and sediment discharge from the upstream. The second EOF mode reveals a close relation between the back-silting strength and project activities. Because the processes are greatly interrelated in this study case, the other EOF modes accounting for 41.67% of the total variance do not show clear processes and time-scales.  相似文献