A flume test on erosion mechanism for an abandoned section of the Huanghe (Yellow) River Delta     

高涛  李广雪  史经昊  刘杰 《中国海洋湖沼学报》2010,28(3):684-692

The erosion mechanisms of abandoned coastal section are understood detailedly by flume experiment, which play an important role to the offshore engineering facilities. A movable-bed physical model has been used to investigate the coastal erosion of an abandoned section of the Huanghe (Yellow) River Delta. The theory of physical scale models is discussed and a method for constructing the representative seabed section is developed. The results indicate that during the period initially after the abandonment of the delta the entire bed experienced rapid erosion because the seabed was steep and prone to liquefaction that resulted from storm wave action. After this initial period, a balance of erosion and accretion was established, and the beach profile equilibrated with a point of balance present on the profile. The experimental results indicate that the volume of deposition was about half that of the erosion. Wave action may also induce significant stratal changes through its interaction with the soft seabed. The major morphological features developed in the model delta section were found to be qualitatively comparable with those observed in the prototype. A distorted modeling law that maintains the similarity of the modeled and prototype equilibrium beach profiles is proposed. Experimental results show that the distorted modeling is able to reproduce the beach-face slope in nature, and the model also successfully reproduced three historical evolutionary stages of erosion.  相似文献   

A flume test on erosion mechanism for an abandoned section of the Huanghe(Yellow)River Delta     

高涛  李广雪  史经昊  刘杰 《中国海洋湖沼学报》2010,(3)

The erosion mechanisms of abandoned coastal section are understood detailedly by flume experiment, which play an important role to the offshore engineering facilities. A movable-bed physical model has been used to investigate the coastal erosion of an abandoned section of the Huanghe (Yellow) River Delta. The theory of physical scale models is discussed and a method for constructing the representative seabed section is developed. The results indicate that during the period initially after the abandonment of the delta the entire bed experienced rapid erosion because the seabed was steep and prone to liquefaction that resulted from storm wave action. After this initial period, a balance of erosion and accretion was established, and the beach profile equilibrated with a point of balance present on the profile. The experimental results indicate that the volume of deposition was about half that of the erosion. Wave action may also induce significant stratal changes through its interaction with the soft seabed. The major morphological features developed in the model delta section were found to be qualitatively comparable with those observed in the prototype. A distorted modeling law that maintains the similarity of the modeled and prototype equilibrium beach profiles is proposed. Experimental results show that the distorted modeling is able to reproduce the beach-face slope in nature, and the model also successfully reproduced three historical evolutionary stages of erosion.  相似文献   

SEDIMENTARY EVOLUTION OF MODERN HUANGHE RIVER DELTA LOBE     

薛春汀  李广雪 《中国海洋湖沼学报》1995,13(4):325-331

The sedimentary history of a Huanghe(Yellow)River delta lobe can be divided into four stages.In the first stage,the crevasse splays and short-lived distributary channel deposits in the subaerial deltaand sheet silt in the subaqueous delta were well developed.In the second stage,further differentiationof sedimentary environments occurred in the subaerial delta lobe(distributary channel,natural levee,flood plain,central lower delta plain and lateral lower delta plain)and the subaqueous delta lobe(prodelta,delta front and delta lateral).In the third stage,crevasse splay and short-lived distributarychannel deposits mostly occurred in the lower or lower-middle part of the subaerial delta lobe,andsheet silt accumulated off the river mouth.In the fourth stage,the abandoned lobe was reworked.The common vertical sequence of the modern Huanghe River delta showed alternating clayey silt andsilt layers.A complete sequence from prodelta to upper delta plain was commonly composed of twoor more delta lobes.  相似文献   

基于时序InSAR的即墨市区地表形变监测     

梁泽浩  王晋  李广雪 《测绘与空间地理信息》2021,44(1):77-81

地面沉降是一种对地面及地下基础设施造成安全隐患,对经济可持续发展和环境保护产生破坏影响的地质灾害现象。本文使用2017年5月至2018年5月16景Sentinel-1A卫星SAR影像,根据D-InSAR的初步形变监测结果将即墨城区内沉降明显的区域作为研究区,基于PS和SBAS两种时序InSAR方法对该区域进行地面沉降监测,获得的沉降分布和形变时序结果吻合。地面沉降的分布与新建高层建筑区吻合,地面形变趋势与区域降水量和地下水水位变化有较高的相关性。研究结果有助于了解即墨城区的地表沉降状况以及原因,为地面沉降综合治理和地下水水资源开发利用提供参考依据。  相似文献   

日照滨海地区岸线和土地利用演变研究     

崔妍  于迪  郝义  种衍飞  冯英明  李广雪  张蕾  杨帆  臧浩 《海洋地质与第四纪地质》2022,(3):76-86

海岸带地区是日照市旅游资源的主要汇集地,承担着日照经济文化发展的中心任务。本文选取1988、2000、2011、2018年4期的夏季Landsat影像,对日照海岸带地区岸线多样性指数和岸线变化速率进行分析,采用最大似然法对海岸带地区土地利用进行监督分类研究,探究日照海岸带近30年来土地利用演变。研究表明,日照市在1988—2018年间岸线长度显著增加,人工岸线年均增长率为2.35 km/a,而砂质岸线长度显著减少,年均减少率为0.56 km/a;总体上岸线以向海扩张为主,扩张最剧烈的地区为日照港和岚山港。日照东港区和岚山区耕地面积基本保持不变;建设用地面积大幅增加,林地面积大幅减少,而水体和未利用地总体面积保持稳定,人类的建设活动是驱动日照滨海地区岸线与土地利用现状演变的最主要因素。本研究结果可为日照海岸带可持续开发利用以及城市未来规划决策提供依据。  相似文献   

基于磁学和粒度参数的黄河三角洲刁口叶瓣地区全新世以来的地层演化   总被引：2，自引：1，他引：1  

刘修锦  王永红  李广雪  孙涛  张卫国 《沉积学报》2014,32(3):518-526

黄河三角洲刁口叶瓣经历了完整的亚三角洲自然发育过程,因此研究其现代发育过程以及全新世以来的地层演化,对于认识整个现代黄河三角洲的形成过程具有重要的理论意义。通过对刁口叶瓣北部的ZK10-3和ZK30孔沉积物粒度、环境磁学参数的测量分析,以及AMS 14C测定,结合收集的刁口叶瓣南部的ZK227、ZK1和ZK228钻孔数据结果,探讨了黄河三角洲刁口叶瓣地区全新世以来的地层演化以及刁口叶瓣的现代形成过程。结果表明该地区全新世以来大致经历了浅海-河湖-盐沼-浅海-三角洲等沉积环境演变过程。1855年来,该地区接受黄河三角洲沉积,依次经历了前三角洲沉积-三角洲侧缘沉积-三角洲平原沉积。1964年刁口叶瓣开始形成,其演化大致经历了漫流淤积-单一河道沉积-出汊改道沉积-废弃蚀退四个阶段。和密西西比河三角洲的叶瓣发育模式相比,由于河流泥沙含量高,因此漫流沉积较为发育。  相似文献   

山东半岛沿岸流强度与悬浮体时空变化特征     

杨雪  李广雪  丁咚  王祥东  刘雪  刘世东 《海洋地质前沿》2023,(1):49-58

基于2014-2018年NOAA/AVHRR遥感数据，在山东半岛海域选取6条剖面，结合海表温度和表层悬浮体的时空变化特征，详细研究了山东半岛沿岸流的年周期变化规律与移动路径。研究结果表明，山东半岛沿岸流年周期变化可分为4个阶段：成长期（10-12月）时开始形成于黄河口附近，沿莱州湾南部向东运移；强盛期（次年1-3月）时山东半岛沿岸流完全成型，扩散带最宽，鼎盛时期北部可以至38°N附近，东部可以至123°E附近，在35°～36°N附近分成NE-SW向的2个分支，主干部分最远可到达胶州湾东部海域，余流沿岸向西南方向转折；衰退期（4-6月）时沿岸流强度减弱，只在山东半岛北部和东部小范围内有微弱的显示；消亡期（7-9月）时基本消失。山东半岛沿岸流在冬季时对悬浮体扩散具有强烈的驱动作用，使其在黄河口南侧与山东半岛北岸-成山头东部海域分别形成呈“弧形”和“条带状”分布的2个高浓度区域。  相似文献