为海洋生态保护和海岸工程建设等工作提供参考,基于Mike21模型水动力学(HD)模块,得到最新岸线形态下芝罘湾的潮流场,涨、落潮历时不均,落急潮流流速大于涨急潮流;东北岸流速最大,向西南靠岸渐小;湾北涨、落潮流向相反,湾中、南部流向在涨急时刻为SW向,落急时刻由南呈NW向向北顺时针逐渐转为NE向.计算了15个潮周期的欧拉余流场,余流流向除湾南沿岸局部区域沿岸向南外,整体为中心在湾东北的顺时针余环流,余流流速整体较小,大部分区域不超过0.06 m/s.芝罘湾内等距离释放16个自由粒子,据粒子运移轨迹得知:湾以北外海的物质不易向湾内输运,湾内自由粒子最终均运移出湾外,湾内无聚集,表明芝罘湾的水动力情况利于物质向外输运;担子岛以北的粒子向东输出湾内后,绕开担子岛等岛屿输运至东南外海;担子岛以南的粒子经过在湾内回旋振荡,以"∞"型轨迹最终南下.

为了解三门湾海域表层沉积物重金属的含量和分布特征,本研究对三门湾海域2019年82个站位海域表层沉积物中的Cu、Pb、Zn、Cd、Cr、As及Hg共7种重金属元素的含量进行测定,并对比10年前的数据,分析了元素含量的变化情况,追溯了其主要物质来源.结果表明,三门湾海域表层沉积物中Cu、Zn、Pb、Cd、Cr、As、Hg的平均质量浓度分别是31.33、96.46、29.86、0.116、91.54、13.09、0.06 mg/kg,Cu、Cr的含量相对较高.与2009年相比,2019年三门湾海域表层沉积物Cu、Zn与Cd的含量大体上保持一致,Pb、Cr与As的含量有所上升,Hg的含量显著降低.沉积物重金属含量由近岸向外海依次降低,高值区主要集中在蛇蟠水道口、力洋港与健跳镇附近.运用主成分分析与因子分析对重金属物质来源进行解析的结果表明,重金属物质的来源与人类活动的影响密切相关.

分水岭迁移和河流袭夺是河流演化研究中的一个重要内容.针对柴汶河袭夺河流域进行袭夺前水系的重建与恢复的问题,首先,基于ArcGIS软件对分辨率为30 m的原始DEM数据进行处理,利用均值变点分析法确定柴汶河袭夺河流域的最佳集水面积阈值,提取与实际较为符合的河网水系;然后,基于二次曲线内插法相似原理对被连接分水线所途经的栅格单元重新赋值;最后,以流域地貌特征演化对河流袭夺机理佐以验证.研究结果表明:当集水面积阈值为0.54 km 2时,提取的河网水系最接近于实际水系;利用内插法等算法得到的结果可知,通过抬高袭夺处的高程来重建恢复袭夺前水系流域的方法是科学可行的.根据其流域地貌演化可知,古柴汶河上游的河流纵比降大于古沂河上游,对应的下蚀和溯源侵蚀能力强,故易能首先切穿分水岭,袭夺古沂河上游.

Underwater cultural heritage (UCH) contributes to history, the arts, the economy and science. The number of intact and easily discoverable UCH sites is decreasing due to excavation in China. To conduct active surveys for mapping archaeological sites, rather than mapping based only on incidental reported finds from fishing operations, a regional archaeological underwater survey method is proposed according to independent geographical units and historical archives. This method is based on the approach used for systematic regional archaeological surveys on land and comprehensively examines similar survey examples. Old port districts, sea routes, fishing zones and naval battle areas are potential targets for this method. From 2012 to 2017, the survey method performed well when applied in the Haitan Strait, China, discovering intact sites, fragmented shipwrecks and numerous interfering objects. The method needs further refinement to eliminate interference and to obtain more detailed information about UCH. The main steps in this method include the selection of potential wreck site areas, the use of sequential equipment and survey line design. Cooperation between archaeologists and surveyors is essential.

选择1976?2020年9期Landsat卫星遥感影像提取海岸线,从海岸线类型多样性指数、海岸线粗糙度、岸线变迁速率对黄河三角洲地区岸线近期演变进行定量分析,并对2030年海岸线形态进行预测,结果表明:44年来,海岸线类型多样性指数变大,海岸线类型趋向多样化;海岸线形态粗糙,海岸线粗糙度曲线由相对平滑变为相对粗糙,形成众多"锯齿"状波动,后逐渐变平滑;河口地区岸线快速向海推进,河口两侧地区岸线则以退蚀为主;部分人工岸线向海快速推进后基本保持不变;经预测,2030年黄河三角洲河口地区,清8汊流路附近及宋春荣沟至虎头崖段岸线向海延伸,东风港至孤东油田段海岸线以侵蚀后退为主.

利用XRD方法分析了三门湾表层沉积物中的黏土矿物组成和含量,结合沉积物粒径趋势分析及长江和三门湾流域中小河流的黏土矿物组合特征,开展了三门湾沉积物的来源分析.结果表明,三门湾表层沉积物中黏土矿物以伊利石为主,其次为高岭石和绿泥石,蒙脱石含量最低.其中,伊利石高值区位于海湾中部,高岭石和绿泥石高值区分布在港汊附近,蒙脱石则在近岸呈斑块状分布.三门湾现代表层沉积物主要来源于长江入海物质,海湾周边短源山溪性河流带来的物质仅影响了河口近岸区.

在人类活动的影响下,径流和泥沙过程的变化受到越来越多人的关注.研究椒江流域水沙变化特征及人类活动影响因素,对椒江流域生态保护和高质量发展具有重要意义.利用椒江流域降水、径流、输沙和遥感影像等长期监测数据,采用多种方法综合分析椒江流域降水、径流和输沙演变特征,包括对椒江流域水文观测资料进行线性回归趋势分析,使用Mann-Kendall突变检验法、滑动t检验法、距平累积曲线法和双累积曲线法进行水文序列的突变检验,使用小波和功率谱进行水文序列的周期分析.在此基础上,采用线性回归方法估算人类活动和气候变化对椒江流域输沙变化的贡献率,最后讨论了人类活动对椒江流域水沙变化的影响.结果表明:椒江降水量存在2～3、4～5、8～9和15～18 a周期;径流量存在2～3、8～9、14～15和18 a周期;输沙量存在2～3、8、12～15和19 a周期.永安溪、始丰溪年降水量、年径流量和始丰溪年输沙量没有显著变化,永安溪输沙量显著减少,63 a间下降了28％.人类活动对永安溪输沙减少的贡献率为86.5％～98.7％,对始丰溪输沙变化的贡献率为50.3％～83.2％.椒江流域水库建设使得年内流量高峰期由6月份向8、9月份发生转移,起到了很好的"蓄峰"作用.流域内土地利用/覆被发生的显著变化以及植被覆盖度的上升降低了流域产沙能力、减少了河流输沙量.

海底沙体是海洋资源开发利用、环境保护、灾害防治和军事行动等必须密切关注的底质类型.台湾海峡沙体面积分布广泛,主要有台湾浅滩、台中浅滩及海峡内受中小型山溪性河流影响的沙体.近年来,台湾浅滩沙体空间分布、大型沙波与小型沙波形态特征及剖面结构研究等领域取得了许多新进展;台中浅滩不同区域的沙体演化对应了地貌发育的不同阶段;而海峡西侧陆架上残留的中小河流沙体地貌也获得了一些新发现.本文归纳了台湾海峡窄陆架上不同沙体的平面分布特征、剖面结构及成因.今后工作的重点应聚焦于进一步获取不同区域高分辨率的地层、地貌证据,并进行对比研究.这些工作能深化对末次盛冰期以来台湾海峡不同地区沙体成因、关联及演化的认识,并有助于了解人类海洋活动与海底沙体演化的响应关系,丰富海底沙体发育和演化理论.

地形起伏度是描述地貌形态、反映地面起伏特征的重要指标.以山东省SRTM数据为基础,利用ArcGIS软件的邻域分析功能和均值变点分析法确定136.89×104 m2为最佳统计单元面积,提取山东省地形起伏度并绘制分级图.结合地形起伏度与海拔,将山东省地形划分为低海拔平原、低海拔丘陵、低海拔台地、小起伏低山和中起伏低山,整体地势较为平缓、起伏较小.

为掌握莱州湾潮余流特征和粒子运移特征,文章采取平面二维数值模拟的方法,计算得到莱州湾的潮流场,并分析潮流结构;在潮流场的基础上,计算和分析欧拉余流场;通过在不同位置释放自由运动的粒子,得到潮流作用下自由运动粒子的运移轨迹.研究结果表明:莱州湾涨潮时的最大流速约为2.19 m/s,落潮时的最大流速约为2.66 m/s,且均在湾口处出现最大流速;莱州湾欧拉余流速度较小,且湾口附近较大而湾内较小;莱州湾分布均匀的粒子在自由运移时出现不同程度的聚集,且整体运移趋势是向岸聚集.

为了解辽东湾海域表层沉积物重金属的污染特征,利用原子吸收分光光度法及原子荧光法测定了辽东湾33个站位表层沉积物中Hg、Cu、Pb、Cd、Cr、Zn及As共7种重金属的含量,同时应用地累积指数法及潜在生态风险评价法对辽东湾海域进行了污染程度及潜在生态风险评价.结果 表明:(1)重金属相关性及主因子分析表明,辽东湾表层沉积物中Zn、Cu、Pb、Cr、Cd、As和Hg可能具有同一污染源;(2)辽东湾海域表层沉积物中Hg、Cu、Pb、Cd、Cr、Zn、As的平均质量浓度分别为0.09、18.81、20.55、0.35、34.15、52.94、5.84 mg/kg;(3)重金属污染程度由高到低依次为:Cd＞ Hg＞Cu＞ Pb ＞Zn ＞As＞ Cr;(4)单个重金属生态风险由高到低依次为:Hg＞ Cd ＞As ＞Cu ＞Pb＞ Cr ＞Zn,研究海域除锦州湾13号站位附近具有很高的生态风险外,其他海域生态风险处于轻微或中等生态危害水平.

River capture is a dramatic natural process of internal competition through which mountainous landscapes evolve and respond to perturbations in tectonics and climate. River capture may occur when one river network grows at the expense of another, resulting in a victor that steals the neighboring headwaters. While river capture occurs regularly in numerical models, field observations are rare. Here we document a late Pleistocene river capture in the Yimeng Mountains, China that abruptly shifted 25 km 2 of drainage area from one catchment to another. River terraces and imbricated cobbles indicate that the main channel incised 27 m into granitic bedrock within 80 kyr, following the capture event, and upstream propagating knickpoints and waterfalls reversed the flow direction of a major river. Topographic analysis shows that the capture shifted the river basins far from topographic equilibrium, and active divide migration is propagating the effects of the capture throughout the landscape.

The vertical distribution of clay minerals in the short cores B44, YSZD01, and DH8-1 collected from typical mud deposits in the North Yellow Sea, Central South Yellow Sea, and East China Sea and associated geological significances were examined based on the analysis of Pb-210 and Cs-137 dating, ratios of kaolinite/illite and smectite/chlorite, illite crystallinity, and illite chemical index. The sediments of mud deposits of the North Yellow Sea are mainly from the Yellow River (Huang He) with that of the inner East China Sea being mainly from the Yangtze River (Changjiang), while sediment sources of mud deposits of the Central South Yellow Sea mainly include the Yellow River and the old Yellow River delta. For cores B44 and DH8-1 with a single main source, both illite chemical index and illite crystallinity have a close relationship with temperature and precipitation in the sediment-source river basin except for YSZD01 with a multi-source. Generally, the ratios of kaolinite/illite and smectite/chlorite indicate that chemical weathering strengthens while physical weathering weakens within the source river basin for the mud sediments from the North Yellow Sea to the Central South Yellow Sea to the East China Sea. In general, illite percentage would decrease, while kaolinite percentage would increase for cores B44, YSZD01, and DH8-1 if the East Asian Winter Monsoon was enhanced in the past 100 years.

The study of the stratigraphic structure of a large river-dominated delta formed by a natural river system is beneficial to understanding the delta sequence stratigraphy,river avulsion and sea-level rise.Using the data of grain-sizeand C-14 dating of a 78 m long drilling core in the Huanghe (Yellow River)Delta,together with previous studies,we divided sedimentary facies of GJ1 borehole from the late Quaternary by methods of sequence stratigraphyand chronostratigraphy.The GJ1 core formed during about 60 ka B.P.to present.From below to top,the sedimentary faciesof GJ1 core are,(1)delta,fluvial and delta deposits at depth of 49.2～78.0 m.(2)fluvial sediment (45.9～49.2 m),formed during MIS4period.(3)coastal,nearshore and fluvial deposits (24.6～45.9 m).(4)fluvial sediment (19.4～24.6 m).(5)Holocene fluvial,coastal,delta front,interdistributary bayandfluvial deposits(above19.4 m),including the riverbed during 1917-1926 and abandoned channel deposits above 4.5 m.In addition,this paper attempts to compare the grain size parameter with the Holocene climate change records,and we found that the average grain size of the GJ1 core is relatively coarsein the cold period and wise versa.And three period of "cool poles,dry tropics"events can be identified at 6 500～6 000 cal yr B.P.,4 200～3 800 cal yr B.P.and 3 500～2 500 cal yrB.P.

The well-known Three Gorges Dam (TGD) within the Yangtze catchment launched its operation in 2003. The effect of the TGD operation on the sediment size on the East China Sea shelf is rarely known. High resolution (0.5 cm sampling) grain size analysis and 137Cs and 210Pb dating of the DH8-1 core were conducted with core collected from the distal part of a main sink for the modern Yangtze sediment entering the sea, the Min-Zhe Coastal Mud Deposits (MZCMD) on the inner East China Sea shelf. The 137Cs dating results show that the core DH8-1 formed during 1946–2012 with a mean deposition rate of 0.65 cm yr−1, indicating that the 0.5 cm sampling for grain size analysis in this local area could reflect environmental changes generally on a one-year time scale. The mean grain size of DH8-1 core sediment that deposited after 2003 is significantly larger than that deposited during 1988–2002. After ruling out other possible factors, we infer that the sediment coarsening of DH8-1 core after 2003 is attributed to the TGD operation which causes the erosion of the Yangtze subaqueous delta. Specifically, the TGD operation significantly intensifies the declining trend of the Yangtze sediment loads to the sea despite no decreased water discharge, which results in extensive erosion of the Yangtze subaqueous delta. The relatively coarse sediment of the subaqueous delta is eroded and resuspended by ocean dynamics and then transported by coastal current, finally depositing on the MZCMD area. In addition, the general sediment fining of core DH8-1 that deposited during 1988–2002, comparing with 1946–1987, is mainly caused by dam construction and soil and water conservation within the Yangtze catchment. Our findings are helpful for better understanding the effects of such a huge dam as the TGD on a sediment sink like the MZCMD of such a large river as the Yangtze River.

目前黏土矿物分析主要依据XRD衍射峰的峰高或峰面积统计量,为了分析两种统计量计算黏土矿物相对含量的差异.对取自黄海的YSZD02岩心短柱开展了黏土矿物XRD测试,分别利用峰高和峰面积表示4种主要黏土矿物蒙皂石、伊利石、高岭石、绿泥石的相对百分含量,探究两种统计量表示黏土矿物相对含量随深度变化的差异,结果发现两算法都能显示黏土矿物的相对组成特征,对YSZD02岩心而言,其黏土矿物主要为伊利石,其次为高岭石,再次为绿泥石,最次为蒙皂石.两种算法得到的4种矿物的相关系数由高到低依次为:高岭石0.94,绿泥石0.93,蒙皂石0.82,伊利石0.73,呈正相关.峰面积法求4种矿物的相对含量随深度变化的离散程度比峰高法大.用峰高、峰面积法表示黏土矿物相对含量随深度的变化,两种方法相对差异由小到大依次为伊利石,高岭石,绿泥石和蒙皂石.以上结果表明两种算法既有共性又有明显的差异.随着分析技术的不断更新,相较于峰高法较难解决的误差问题,未来峰面积法会得到更广泛的应用.因此研发更精确的计算机分析软件、统一研究方法将是未来发展的必然趋势.本文的研究加深了对峰高与峰面积统计量的理解,为其他分析方法的比较与选择提供了参考.

The sedimentary evolution of the ancient Huanghe (Yellow River) Delta in China is not well documented due to frequent river-avulsions and limited deep cores. In this paper, 22 cores with lengths of >20m at the coastal plain along the southwestern Bohai Bay were used. The sedimentary facies were determined by grain size and microfossil analysis, and Carbon-14 dating. The strata in the study area since the Last Glacial Maximum (LGM) are divided into lowstand system tract (LST), transgressive system tract (TST), highstand system tract (HST), and retrograding system tract (RST). The LST, which formed during the LGM to 10.8kaBP, consists of hard mud layer, and overlying interfluvial lowland and flood plain deposits. The TST that formed during 10.8–8.5kaBP, mainly include coastal marsh, onshore sand bars, and filled incised valleys. The HST that formed during 8.5–2.6kaBP mainly includes flood plain, river channel, delta front, mouth bar and prodelta. The RST that formed after 2.6ka BP mainly includes crevasse splay, interfluvial lowlands and distributary channel. About eight episodes of the ancient Huanghe (delta) are observed during the Holocene and the names of the deltas are given by corresponding location names of cheniers: (1) during 10.8–8.5kaBP, around YS3 and NP1 cores, without formation of cheniers during the transgression, (2) during 8.5–7.4kaBP, around YS1, YS4 and NP3 cores, the Dongsun-Shuiyicheng delta, (3) during 7.4–6.1kaBP, around CK1 core, the Mashanzi delta, (4) during 6.9–5.7kaBP, around GZ3 core, the Miaozhuang-zhaizhuang delta, (5) during 4.6–3.5kaBP, around YS4 core, the Wuditai delta, (6) during 3.0–2.6kaBP, around HH4 and HH1 cores, the Qikou delta, (7) during 2.6–1.9kaBP, around YS7 and NP1 cores, the Nanpaihe delta, and (8) during 1034BC–1099BC, around Wangzidao and Dakouhe, the Wangzidao delta.

The periodicity analysis and correlation analysis about river runoff and basinwide precipitation in a river are widely used. While there exists a problem in previous periodicity analysis and correlation analysis, which here refers to lacking consideration of human impacts on river runoff. This problem may obscure the results of periodicity analysis and correlation analysis. For the case of the Yangtze River and the Yellow River, we carried out periodicity analysis and correlation analysis about river runoff and basinwide precipitation. The primary analyses without consideration of human impacts show that there are clear periods and high correlation between annual runoff and annual precipitation of the Yangtze River in humid zone, while the periods and correlation are not clear in the Yellow River in arid and semiarid zones. The discussion indicates that water consumption within the Yellow River basin is often in the same order of magnitude as that of actual water discharge, which could affect the periodicity analysis and correlation analysis. Therefore, one argument is presented that human impacts (i.e. water diversions) on the river runoff should be considered in the process of periodicity analysis and correlation analysis of a river between arid and semi-arid climatic zones, where water consumption is often in the same order of magnitude as that of actual water discharge.

用激光粒度仪对南黄海中部(YSZD01孔)与北黄海西部(B45孔)泥质区沉积物短柱样进行高分辨选样(0.5 cm)的粒度测试与分析,并对柱样进行210pb测年分析.B45孔柱样沉积时间为1913～ 2010年,沉积物以粉砂为主,粒度参数垂向波动较大.YSZD01孔柱样沉积时间为1909 ～ 2012年,沉积物为泥与砂质泥,粒度参数垂向变化较小.两孔在1958年、1971年、1980年左右砂含量突增,很可能归因于强度大的寒潮,其增强了黄海两泥质区的水动力环境,导致两孔在这些年份左右的粗颗粒沉积物含量突增.用粒级-标准偏差法得到B45孔沉积物敏感粒级组分为15.6～71.8 μm,YSZD01孔沉积物敏感粒级组分为23.7～500.0μm,用其作为东亚季风变化的指标,显示自1910年代以来东亚冬季风强度增强,两孔在1925～ 1935年、1955～ 1964年、1974～ 1977年、1982～1986年这四个时期敏感粒级含量出现增加趋势,对应冬季风强度增强较为明显.从岩芯粒度来看,季风强度的变化体现为敏感粒级组分含量变化,季风频率的变化体现为敏感粒级含量波动的程度.

The paper intends to present our analysis of As content of surface sediment samples collected from 31 stations in adjacent sea areas of Yangtze Estuary in October,2011 with an atomic fluorescence spectrophotometer.On the basis of the analytical results,we have made a detailed discussion of the spatial distribution of the poisonous element As and its source in the above said area.The results of our analysis show that the content of As in the surface sediments of the area under discussion varies between 0.92 mg/kg and 23.25mg/kg with average of 6.98 mg/kg.The content should be considered to be a great deal higher at the near-shore stations,especially in argillaceous sedimentary areas,though lower at the offshore sea waters.Generally speaking,the distribution of As exhibits in an obvious belt-shaped pattern.The excessive content of the toxic element is closely correlated with the grain-size distribution of sediments:the finer the sediment particles are,the higher the content of As in it,which indicates that the fine particles,the main carrier of As,exert a dominant influence on the distribution of As.In addition,the statistical results prove that the content is weakly positively correlated with the contents of organic carbon and the total nitrogen,which suggests that the organisms may pose a certain influence,but not a controlling one on the distribution of As.With reference to the distribution analyses of the marine current system in the area under question,the distribution of the higher As content in the area is consistent with the distribution of the diluted water of the Yangtze River and the littoral currents,which suggests that on the one hand,As mainly originates from the suspended fine particles flouting in the water and carried by the Yangtze influx into the East China Sea,on the other hand,its distribution is mainly influenced by the diffusion of the Yangtze influx and the littoral currents.In the final analysis,As has been slightly enriched in the area under study,with its enrichment factor higher at some stations than at the others.This indicates that there are human-originated pollution and potential environmental risks in the adjacent sea areas of the Yangtze Estuary.