北黄海大鹿岛附近海域海洋牧场本底地质环境分析

Analysis of Background Geological Environment of Marine Ranching near Dalu Island in the North Yellow Sea

关键词:  海洋牧场  海底地形地貌  沉积特征  水文环境  北黄海  大鹿岛

Key words:  marine ranching  submarine topography  sedimentary characteristics  hydrological environment  North Yellow Sea  Dalu Island

摘要:

为推进北黄海北部特色滩涂型海洋牧场建设，本研究对北黄海大鹿岛附近海域海洋牧场本底地质环境开展调查评估，利用高分辨率声学探测设备获取研究海域的精密水深数据和浅地层剖面数据；利用现场和实验室结合的方法测定海水理化参数；利用筛析法、激光粒度仪测试方法确定沉积物类型和粒度特征，最终通过分析研究区海底地形地貌、海水水质状况和沉积物分布特征对本底地质环境进行评估。结果显示：目标海域测量水深为1-29 m，平均水深为16 m，海底地形整体表现为平缓的近岸缓坡，地貌以水下侵蚀堆积地貌为主；海底浅地层剖面中U1声学地层清晰连续，全区可追踪，厚度约6 m且变化不大；海水水质良好，主要处于Ⅱ类海水水质标准；表层沉积物类型均为砂，沉积物组分变化不大，砂组分占绝对优势，表层沉积物空间分布主要与沉积物物源条件及辽南沿岸流、海域潮流等因素有关。综合分析认为，北黄海大鹿岛附近海域水深适宜，地形较为平坦，水质环境良好，以砂质浅滩沉积为主，适于滩涂型海洋牧场的构建。

Abstract:

In order to promote the construction of characteristic beach-type marine ranching in the northern part of the North Yellow Sea, a survey and assessment of the background geological environment of marine ranching near Dalu Island in the North Yellow Sea was carried out in this study.High-resolution acoustic sounding equipment was used to obtain precise bathymetric data and shallow stratigraphic profiles of the study area.The physicochemical parameters of seawater were determined by the combination of field and laboratory methods.Sieving analysis and laser particle size testing were used to determine the sediment type and particle size characteristics.Finally, the background geological environment was assessed by analyzing the submarine topography, seawater quality and sediment distribution characteristics of the study area.Results show that the measured water depth of the target sea area is 1-29 m, with the average water depth of 16 m.The overall performance of submarine topography is generally a gentle near-shore slope, and the landform is dominated by underwater erosion accumulation landform.The U1 acoustic strata in the seafloor profile is clear and continuous, traceable throughout the area, with a thickness of approximately 6 m and little variation.The seawater quality is good, mainly in Category Ⅱ seawater quality standard.The types of surface sediments are all sand, and the composition of sediments does not change much.The composition of sand is absolutely dominant.The spatial distribution of surface sediments is mainly related to the sediment source conditions and the factors such as the coastal current in southern Liaoning and the tidal current.The comprehensive analysis shows that the water depth near Dalu Island in the North Yellow Sea is suitable, the terrain is relatively flat, the water quality environment is good, and the deposition are mainly sandy shoal, which is suitable for the construction of beach-type marine ranching.