黄河三角洲近岸海底浅表层典型灾害地质类型发育机制及其分区

发布时间：2017-12-28 22:00

本文关键词：黄河三角洲近岸海底浅表层典型灾害地质类型发育机制及其分区　出处：《中国海洋大学》2015年博士论文　论文类型：学位论文

【摘要】：我国是世界上地质灾害最为严重的国家之一,据统计每年因地震、崩塌、滑坡、泥石流,以及海岸侵蚀、地面沉降等地质灾害所造成的直接经济损失高达近千亿元。同时,随着海洋油气资源勘探开发活动的迅速扩大,许多灾害地质相关问题逐渐显露出来。众所周知,黄河三角洲地区是主要海洋石油的开采区,因灾害地质事件而发生的管道的断裂、钻井平台滑移的事件时有发生,海洋石油开发的安全面临着严重的潜在威胁。基于此,本论文根据黄河三角洲近岸海域大范围高分辨率浅地层剖面和侧扫声纳数据的解译分析,进行灾害地质类型的圈定识别,对典型灾害地质类型的发育机制进行探讨。利用聚类分析的方法进行灾害地质分区研究,并从灾害地质类型形成发育4个主要影响因素的区域分异特征探讨分区的合理性。本论文的研究一方面对于从浅地层剖面和侧扫声纳图谱上进行灾害地质类型的识别提供一定的方法与经验借鉴,另一方面可全面系统掌握黄河三角洲区域灾害地质类型与特征,研究成果可为黄河三角洲区域海洋石油开发提供安全保障。本论文依托国家908专项“QC07区块海底浅层剖面和侧扫声纳调查研究”,国家海洋公益性行业经费项目“黄河三角洲海底浅层标准声学层序与典型灾害地质”,以及国家海洋局青年科学基金项目“基于浅地层剖面探测的黄河尾闾流路变迁研究”,基于覆盖黄河三角洲近岸海域约3200km的侧扫声纳和浅地层剖面数据资料,围绕近岸海底表层和浅部地层发育的典型灾害地质类型开展研究,对典型灾害地质类型特征、空间分布进行分析,对其形成过程和发育机制进行探讨。在上述工作的基础上,对灾害地质类型形成发育的影响因素及其区域分异特征进行探讨,利用聚类分析的方法探索性开展黄河三角洲近岸海域灾害地质分区研究,从黄河入海水沙通量、海床稳定性、海洋水动力和底质沉积物类型与分布4个主要影响因素探讨分区结果的合理性。取得如下主要结论：(1)基于浅地层剖面和侧扫声纳声学图谱的解译分析,圈定辨识黄河三角洲近岸海底浅表层发育了7种典型常见的灾害地质类型,即凹坑、侵蚀残留体、砂斑、沙波、冲刷槽、埋藏古河道和地层扰动。基于覆盖整个黄河三角洲近岸海域的3200km浅地层剖面和侧扫声纳数据,根据浅地层剖面和侧扫声纳数据解译识别出浅部地层灾害地质类型主要是埋藏古河道和地层扰动,海底表层灾害地质类型主要是凹坑、侵蚀残留体、砂斑、沙波和冲刷槽。凹坑、侵蚀残留体和冲刷槽等侵蚀型灾害地质类型主要分布在研究区废黄河亚三角洲刁河口—清水沟海域,研究区中部近岸海域局部亦有分布；砂斑主要分布在研究中、南部近岸海域海底,砂斑分布与砂质沉积分布范围比较一致；沙波主要分布在现行河口及其以南深水海域海底。地层扰动较集中分布在研究区东北部埕岛海域,与粉砂质沉积区具有一致的分布规律。(2)通过浅地层剖面声学图谱—浅部地层埋藏古河道—历史时期黄河尾间流路的研究思路,基于浅地层剖面探测数据解译辨识得到黄河三角洲近岸海域历史时期黄河尾间流路变迁过程,结果表明研究区埋藏古河道大致有3条,呈近NE走向分布。赋存在海底浅部地层中的埋藏古河道,是历史时期河流尾间改道留下的“印迹”。近年来高分辨率浅地层剖面仪的广泛应用,使得近岸海域大范围、高精度与高密度浅地层剖面数据的获取更加便捷,为发现埋藏古河道,追踪反演历史时期河流尾闾摆动变迁过程提供了可能性。以覆盖黄河三角洲近岸海域3200km浅地层剖面数据为基础,围绕高分辨率浅地层剖面声学图谱—海底浅部地层埋藏古河道—近代黄河尾闾流路之间的响应关系开展研究。依据浅地层剖面声学图谱的断面形态特征,以及河流相砂的充填沉积特征,圈定辨识并确认埋藏古河道,量算其空间位置、埋藏层位及其规模范围,结合地质钻孔及古环境信息判断其形成年代。在此基础上,建立不同埋藏层位的古河道与不同年代黄河尾间流路之间的“对应”关系,进而构建近代黄河尾间流路改道变迁过程模式。结果表明：基于浅地层剖面探测的黄河尾间流路研究结果与现有的黄河尾闾流路变迁过程趋势相一致,基本反映了近代黄河尾间流路的变迁过程。利用浅地层剖面解译的方法,共解译识别得到埋藏古河道位置有效点20个,据此构建了三条近代黄河行水流路,三条尾闾行水流路为不同年代黄河现时行水河道。三条解译所得黄河尾间流路基本上为近NE走向,基本确认其为当时黄河尾间的三次行水路线。(3)基于聚类分析方法将黄河三角洲近岸海域划分为5个灾害地质区域,即钓口叶瓣浪控严重侵蚀灾害区、神仙沟叶瓣浪流共同作用多灾种灾害地质区、现行河口河控堆积型灾害地质区、深水区单灾种灾害地质区和埕岛油田潜在灾害地质区。围绕解译辨识出的广泛发育的海底浅部地层灾害地质类型(埋藏古河道、地层扰动),以及海底表层灾害地质类型(凹坑、侵蚀残留体、砂斑、沙波和冲刷槽)7种典型灾害地质类型,划分网格单位,根据灾害地质类型类型数量,以及凹坑深度、侵蚀残留体高度、)中刷槽长度、砂斑面积、沙波波长、埋藏古河道河道宽度和地层扰动深度等表征参数作为分区指标,利用聚类分析将黄河三角洲近岸海域划分为5个灾害地质区域。(4)总结认为黄河三角洲近岸海底浅表层典型灾害地质类型形成发育的主要影响因素有4个,包括：黄河入海水沙通量变化及其扩散运移、波流海洋水动力变化、海岸海床稳定性,以及海底表层底质沉积物类型及分布。黄河一年中的大部分时间内入海平均径流、泥沙通量很小,入海泥沙扩散范围非常小,而调水调沙期间入海泥沙占年入海泥沙总量的30%以上,短期内汇聚巨量泥沙,形成集中输沙,聚沙外输的优势,短时间内完成入海泥沙在河口的集中汇聚,调水调沙试验期间入海水沙通量形成短期巨量高含沙的变化特征,入海泥沙扩散范围扩大,数值模拟结果表明其最大扩散影响范围约20km×40km。黄河入海泥沙变化及扩散影响范围主要影响灾害地质类型发育物源供给,决定着灾害地质类型空间分异；海洋水动力是灾害地质形成的动力因素,决定着灾害地质类型的分布范围和规模；海岸海床稳定性是灾害地质活动性的影响因素,决定着灾害地质类型的活动性；底质沉积物类型决定着局部区域灾害地质类型的空间分异。(5)从灾害地质类型形成发育的主要影响因素的区域分异规律方面分析表明,基于聚类分析方法所建立的黄河三角洲近岸海域海底浅表层灾害地质分区结果具有一定合理性,基本反映了灾害地质类型空间分布和成因机理的区域差异性。基于浅地层剖面和侧扫声纳勘探数据,利用聚类分析方法开展的分区研究,在黄河三角洲近岸海域灾害地质分区研究上是一新的尝试。从海岸海床稳定性、黄河入海水沙通量及其扩散变化、底质沉积物特征与分布,以及海洋水动力4个方面对分区的合理性进行探讨,表明分区结果合理可靠,基本反映了灾害地质分区的区域差异。
[Abstract]:China is one of the most serious geological disasters in the world. According to statistics, the direct economic losses caused by geological disasters such as earthquakes, landslides, landslides, debris flows, coastal erosion and land subsidence every year are nearly 100 billion yuan. At the same time, with the rapid expansion of exploration and development activities of marine oil and gas resources, many related problems of disaster geology have gradually emerged. As we all know, the the Yellow River Delta area is the main offshore oil exploitation area. Pipeline rupture and drilling platform slippage happen frequently due to calamity geological events. The safety of offshore oil development is facing a serious potential threat. Based on this, based on the interpretation and analysis of the high-resolution high-resolution shallow strata profile and the side scan sonar data in the coastal waters of the Yellow River Delta, we have delineated the recognition of the disaster geological types, and discussed the development mechanism of typical disaster geological types. The method of cluster analysis is applied to the study of disaster geological zoning, and the rationality of zoning is discussed from the regional differentiation characteristics of 4 main factors affecting the formation and development of disaster geology. This paper provides some experience and a method for identifying reference types of geological disasters from the shallow profile and side scan sonar map, on the other hand can grasp the comprehensive system with the characteristics of regional geological disaster types in the Yellow River Delta, the research results can provide security for the the Yellow River delta offshore oil development. This paper is based on the national 908 project "QC07 block submarine shallow section and side scan sonar survey, the National Marine public welfare industry fund project" the Yellow River delta shallow water acoustic standard and typical geological disaster sequence ", and the State Oceanic Administration of Youth Science Fund Project" research "change road the Yellow River River flow detection of shallow profile based on the coastal waters of the Yellow River Delta, covering about 3200km based on side scan sonar and shallow profile data, around the study of typical geological disaster type coastal seabed surface and shallow strata, geological disaster types of typical characteristics and spatial distribution are analyzed, the formation and development mechanism. Based on the above work, the types of geological disasters in the formation and development of the influencing factors and the regional differentiation characteristics are discussed, using the method of cluster analysis on the coastal geological disaster zoning in the Yellow River delta development, discuss the rationality of partitioning results from the Yellow River to the sea water and sediment flux, seabed stability, ocean hydrodynamic and sediment the types and distribution of 4 main influencing factors. The main conclusions are as follows: (1) analysis of shallow profile and side scan sonar based on acoustic spectrum interpretation, the delineation of identification in the Yellow River Delta coastal seabed development of 7 typical common geological disaster types, namely erosion pits, residual body, sand spot, Sha Bo, scour channel, buried channel, ground disturbance. Cover the entire the Yellow River Delta coastal shallow profile and 3200km based on side scan sonar data, according to the shallow profile and side scan sonar data interpretation to identify shallow strata, geological hazards are the main types of buried ancient river and ground disturbance, the surface geological disaster type of main body, if erosion pits, residual sand spots, sand and scour trough. The erosion pits, residue and scour erosion type geological disaster types are mainly distributed in the research area of waste the Yellow River Subdelta Diao estuary Qingshui gully area, central area near the study area have local distribution; sand spots are mainly distributed in the study, the South Sea coastal waters, sand spot distribution and the distribution range of sandy sediments consistent; sand mainly distributed in estuarine and deep waters to the South sea. The formation disturbance is concentrated in the Chengdao sea area in the northeastern part of the study area, which is consistent with the silty sedimentary area. (2) through the shallow profile acoustic Atlas of shallow ground buried channel - the Yellow River historical period between the tail flow path research method, shallow profile detection data interpretation identified in the Yellow River Delta coastal waters of the Yellow River in historical period between the tail flow path change process based on the research area of buried channel roughly 3 that is close to NE direction. The buried ancient river in shallow strata of the seabed is a "blot" left by the river tails in the historical period. The application of high resolution Subbottom Profiler in recent years, the coastal waters of large range, high precision and high density of shallow profile data more convenient access, to find buried channel, provides the possibility of tracking the tail swing change process of inversion period. To cover the the Yellow River Delta coastal waters 3200km subbottom profile data based on response relationship between the high resolution shallow profile acoustic Atlas of shallow seabed strata buried channel in the the Yellow River river flow path research. According to section morphological characteristics of shallow profile of acoustic patterns, sedimentary characteristics and fluvial sand, identify and confirm the delineation of buried channel, measure the position, scale and buried layer, combined with the geological drilling and paleo environmental information to determine the age of its formation. On this basis, we establish the corresponding relationship between different buried levels of ancient rivers and the Yellow River intercontinental flow paths in different years, and then construct the process pattern of modern the Yellow River's intercity flow path transformation. The results show that: Based on consistent detection of shallow stratigraphic section of the the Yellow River rear flow path research results and the existing the Yellow River river flow path change trend, basically reflects the modern the Yellow River rear flow path change process. Using the method of shallow profile interpretation, the interpretation identified buried channel position effective point 20, which built three modern the Yellow River water road, three river for water flow path for different water channel in the Yellow River at present. The three interpretation of the the Yellow River tail
【学位授予单位】：中国海洋大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：P744.4;P694

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