本文選題：沉積物分布 + 岸線演變　； 參考：《華東師范大學(xué)》2016年碩士論文

【摘要】：近岸帶地貌動力環(huán)境極為復(fù)雜,其動力、沉積和地貌演變需要深入的研究和理解。四更沙及其鄰近海域位于海南島西部,包含了典型的海灘、沙嘴、海灣系統(tǒng)和三角洲地貌類型。本文基于四更沙及其鄰近海域沉積物粒度數(shù)據(jù),并結(jié)合研究區(qū)動力條件和水深地形特征,研究表層沉積物的組分和類型分布、粒度參數(shù)及其沉積環(huán)境分區(qū)特征,并對其沉積物分布受控機(jī)制進(jìn)行探討。利用四更沙區(qū)域1972年以來8期Landsat影像,采用人機(jī)交互的方式提取干濕線,并以此作為岸線對昌化江河口三角洲海岸、昌化江口-四更沙嘴海岸、四更沙嘴海岸、四更沙嘴以南北黎灣海岸4個海岸的演變動態(tài)分別進(jìn)行探討。最后根據(jù)四更沙海灘表層沉積物分析和RTK高程測量數(shù)據(jù)研究四更沙海灘沉積物特征及地形演變規(guī)律。研究結(jié)果表明：①研究區(qū)沉積物類型多樣,包括12種沉積類型,以砂質(zhì)粉砂、粉砂、粉砂質(zhì)砂和含礫砂為主,沉積物平均粒徑變化范圍較大(-0.70Φ-7.13Φ),且大體呈現(xiàn)由北向南逐漸變細(xì)的分布趨勢。②運(yùn)用Fleming的三角圖式,結(jié)合物源狀況及地形地貌條件,對沉積環(huán)境進(jìn)行劃分,將研究區(qū)劃分為四更沙岸外海濱沉積區(qū)、北黎灣中部沉積區(qū)和八所港近岸沉積區(qū)等3個沉積區(qū)。③研究區(qū)沉積物分布特征受沉積物來源和水動力及地形條件共同影響。橫向分布上,西部主要受強(qiáng)潮流輸沙影響,東部近岸則主要受波浪掀沙和搬運(yùn)作用影響,表現(xiàn)為兩側(cè)粗,中間相對較細(xì)的特征�？v向上,四更沙岸外海濱沉積區(qū),沉積物主要受昌化江影響,粒徑粗,表現(xiàn)為河口沉積特征；北黎灣中部沉積區(qū),沉積物粒徑分布范圍廣,表現(xiàn)為較強(qiáng)的過渡區(qū)特性;八所港近岸沉積區(qū),沉積物粒徑最細(xì),泥沙來源主要為外海帶來的泥沙。④昌化江河口三角洲海岸是岸線變化最為劇烈的區(qū)域,并主要表現(xiàn)為河口三大沙嘴的變化；昌化江口-四更沙嘴海岸,幾乎所有自然岸線都表現(xiàn)為侵蝕,表現(xiàn)為淤積的只有因為沙嘴并陸的少部分自然岸線和人工圍墾岸線；四更沙嘴面積不斷增長,尤其是中部主體增長較快,沙嘴頭部變動頻繁,沙嘴根部則不斷向東遭受侵蝕；四更沙嘴以南北黎灣海岸多為人工岸線,變化不大。⑤自南向北,縱向上看,四更沙海灘表層沉積物粒徑大小呈現(xiàn)為粗-細(xì)-粗-細(xì)的變化規(guī)律。監(jiān)測區(qū)受波流共同作用,水動力環(huán)境比較復(fù)雜,粒度分布較為分散⑥四更沙海灘季節(jié)性變化明顯,凸出岸外岬角南側(cè)的斷面多表現(xiàn)為夏季淤積冬季侵蝕；海灘年變化來看,多為侵蝕海岸。上述研究將有助于復(fù)雜近岸過程的深入理解,同時可為四更沙及其鄰近海域的開發(fā)和管理提供基礎(chǔ)資料和科學(xué)依據(jù)。
[Abstract]:The geomorphologic dynamic environment of the coastal zone is very complex, and its dynamic, sedimentary and geomorphic evolution need to be deeply studied and understood. Located in the western part of Hainan Island, Sand and its adjacent waters contain typical beach, sand mouth, bay system and delta landforms. Based on the sediment granularity data of Sigansha and its adjacent sea areas, the composition and type distribution, granularity parameters and sedimentary environment zoning characteristics of surface sediments are studied in this paper, in combination with the dynamic conditions of the study area and the topography characteristics of water depth. The controlled mechanism of sediment distribution was discussed. The dry and wet lines were extracted by man-machine interactive method using 8 Landsat images in Sigansha area since 1972. The dry and wet lines were used as shoreline to the estuary and delta coasts of Changhua River, the estuary of Changhua River to the coast of Shizengshazui. The evolution dynamics of four coasts along the coast of South and North Lebanon Bay are discussed separately. Finally, based on the surface sediment analysis of Sigansha beach and RTK height survey data, the sediment characteristics and topographic evolution of Sigansha beach are studied. The results show that there are many types of sediments in the study area, including 12 sedimentary types, mainly sandy silt, silty sand, silty sand and gravel sand. The average grain size of sediments varies from 0.70 桅 -7.13 桅 to 0.70 桅 -7.13 桅, and the distribution trend of the sediment is gradually thinning from north to south. 2 the sedimentary environment is divided by using Fleming's triangular diagram, combining with the source status and topographic and geomorphological conditions. The study zonation is divided into four seashore sedimentary areas, three sedimentary areas, I. e., the central sedimentary area of North Li Bay and the nearshore sedimentary area of Bazhonggang. 3. The sediment distribution in the study area is influenced by the sediment source, hydrodynamic and topographic conditions. In the transverse distribution, the west is mainly affected by strong tidal current and sediment transport, while the east coast is mainly affected by wave sand lifting and transport, showing the characteristics of coarse sides and relatively fine middle. Longitudinally, the sediment is mainly influenced by Changhua River, and its grain size is coarse, showing the characteristics of estuarine sedimentation, while in the middle of North Li Bay, the sediment size distribution range is wide, and the sediment is characterized by strong transition zone. The sediment size is the smallest in the near shore sedimentary area of Bazhonggang, and the sediment source mainly comes from the offshore sediment 4.The delta coast of Changhua River estuary is the area with the most dramatic changes along the shore line, and mainly shows the change of the three major sand mouth of the estuary. Almost all of the natural shorelines on the coast of Changhua Estuary and Szongshanzui are eroded, only because of the small part of the natural shoreline and the artificial reclamation shoreline of the sand mouth and the land; the area of the Sand nozzle is growing continuously. In particular, the main body of the central region is growing faster, the head of the sand mouth changes frequently, and the root of the sand mouth is continuously eroded eastward; the coast of the north and south of Lebanon Bay is used as the artificial shoreline in the fourth sewer, with little change of .5 from the south to the north. The grain size of surface sediment on the beach is coarse-fine-coarse-fine. The hydrodynamic environment of the monitoring area is complicated by the interaction of waves and currents, the distribution of granularity is more dispersed and the seasonal variation of the beach is obvious. The section on the south side of the protruding headland mostly shows summer siltation and winter erosion. Most of them erode the coast. The above research will be helpful to the further understanding of complex inshore processes and can provide basic data and scientific basis for the development and management of Sigansha and its adjacent sea areas.
【學(xué)位授予單位】：華東師范大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：P736.21;P737.1

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1 周樂;海南島四更沙及其鄰近海域沉積特征與地貌動力演變[D];華東師范大學(xué);2016年

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