湛江湾红树林湿地沉积柱粒度特征及沉积动力分析

doi:10.19657/j.geoscience.1000-8527.2020.101

摘要/Abstract

摘要：

粒度是反映沉积动力特征的重要参数,红树林湿地沉积物在输送和沉积过程中记录了丰富的沉积环境信息。为探讨湛江湾红树林湿地沉积物粒度垂向特征及沉积动力过程,加强对湿地生态保护,通过运用图解法、对比研究法分析湛江湾南海堤(NHD)、东头山岛(DTSD)、湖光镇(HGZ)和观海长廊(GHCL)4个站位红树林湿地沉积柱粒度参数特征、频率分布曲线以及沉积速率,揭示近百年来湛江湾的沉积动力演变。结果表明:(1)NHD和DTSD沉积柱的²¹⁰Pb_ex比活度都呈现较好的指数衰变趋势,且沉积速率逐年增加。近百年来,NHD和DTSD平均沉积速率分别为1.277 cm/a和1.034 cm/a,但在2011年之后DTSD的速率远超过NHD。(2)各沉积柱粒度特征存在明显差异。NHD沉积柱粒径均值为3.42ϕ,以砂为主(67.23%),为粉砂质砂;DTSD粒径均值为5.71ϕ,分选系数2.21,组分以粉砂为主(55.13%),为砂质粉砂;HGZ沉积柱粒径均值为5.49ϕ,沉积物类型为砂质粉砂;GHCL粒径均值为4.18ϕ,砂为主要组分(55.85%)。(3)各沉积柱4个层位的粒度频率分布曲线呈现多峰态特征,沉积过程掺杂了多种沉积介质的作用。NHD和GHCL粒级集中在砂质颗粒端,指示较强的沉积动力;DTSD和HGZ粉砂粒级突出,沉积动力较弱。(4)沉积物粒度特征与所在陆源或岛屿、径流来沙有关;沉积过程深受潮流动力、红树林的分布及人类活动的影响。近年来湛江湾沉积速率的加快可能会对航道产生影响,应加强对湾内湿地生态环境的重视。

关键词: 湛江湾, 粒度特征, 沉积速率, 沉积动力

Abstract:

Granularity is an important parameter for understanding the sedimentary dynamics characteristics. Mangrove wetland sediments host much sedimentary environment information during the transport and deposition processes. To unravel the vertical grain size characteristics and sedimentary dynamics of mangrove wetland in the Zhanjiang Bay and enhance wetland ecological protection, the grain size parameter characteristics, frequency distribution curve, and sedimentation rate of mangrove wetland sedimentary columns at the Nanhaidi (NHD), Dongtoushan Island (DTSD), Huguang Town (HGZ)and Guanhaichanglang (GHCL)stations were analyzed. Our work reveals the sedimentary evolution of the Zhanjiang Bay in the past century, and our results suggest that: (1)The ²¹⁰Pb_ex specific activity of NHD and DTSD columns both show a good exponential decay trend, with the deposition rate increasing with time. The average deposition rates of NHD and DTSD were 1.277 cm/a and 1.034 cm/a, respectively, but that of DTSD far exceeded that of NHD after 2011. (2)Grain-size characteristics of individual sedimentary column is markedly different, and the average grain size of NHD sedimentary column is 3.42ϕ, mainly composed of sand (67.23%)and is classified as silty sand. The mean diameter of DTSD is 5.71ϕ with sorting coefficient of 2.21. It is mainly composed of silty-sand (55.13%)and is classified as sandy-silt. HGZ is sandy-silt with mean particle size of 5.49ϕ. The GHCL is mainly composed of sand (55.85%)with average particle size of 4.18ϕ. (3)The grain size frequency distribution curves display multimodal features, implying that the deposition process was doped with the process of various sedimentary media. The NHD and GHCL particle sizes are clustered toward the sandy particle end-member, indicating strong sedimentary dynamics, whereas the sedimentary dynamics of DTSD and HGZ is considerably weaker. (4)The grain-size characteristics are influenced by the local terrestrial source, island and runoff, whilst the sedimentation process is significantly influenced by the tidal current dynamics, mangrove distribution, and human activities. In recent years, the rising sedimentation rate in the Zhanjiang Bay may have an impact on the navigation channel, and more attention should be paid to the wetland ecological environment in the bay.

Key words: Zhanjiang Bay, grain size characteristic, deposition rate, sedimentary dynamics

中图分类号:

罗松英, 全晓文, 陈碧珊, 邱锦坤, 梁家新, 邓子艺. 湛江湾红树林湿地沉积柱粒度特征及沉积动力分析[J]. 现代地质, 2021, 35(03): 647-656.

LUO Songying, QUAN Xiaowen, CHEN Bishan, QIU Jinkun, LIANG Jiaxin, DENG Ziyi. Grain Size Characteristics and Sedimentary Dynamics of Sedimentary Column of Mangrove Wetland in Zhanjiang Bay[J]. Geoscience, 2021, 35(03): 647-656.

图/表 6

表1 湛江湾采样记录

Table 1 Sampling record of Zhanjiang Bay

	编号	纬度(N)	经度(E)	岩心长度/cm
南海堤	NHD	21°09'12″	110°29'22″	100
东头山岛	DTSD	21°06'13″	110°23'30″	100
湖光镇	HGZ	21°06'34″	110°18'45″	100
观海长廊	GHCL	21°12'14″	110°24'52″	100

图1 研究区位置及野外现场图 (a)采样站位;(b)南海堤红树林;(c)观海长廊红树林;(d)岩心照片;NHD.南海堤采样点;DTSD.东头山岛采样点;HGZ.湖光镇采样点;GHCL.观海长廊采样点

Fig.1 Location map, field and core photos of the study area

图2 210Pbex比活度纵向剖面图和210Pb沉积速率 (a)(b)分别为 NHD和DTSD 210Pbex比活度纵向剖面图;(c)(d)分别为NHD和DTSD 210Pb沉积速率图

Fig.2 Longitudinal profiles of 210Pbex specific activity and 210Pb deposition rate

图3 沉积柱粒度参数垂向及组分垂向分布图

Fig.3 Vertical distribution of particle size parameters and sedimentary column components (a)NHD;(b)DTSD;(c)HGZ;(d)GHCL

图4 湛江湾各沉积柱粒度频率曲线分布图 (a)(b)(c)和(d)分别为NHD、DTSD、HGZ和GHCL粒度频率曲线

Fig.4 Grain size distribution frequency curves of sedimentary columns in the Zhanjiang Bay

图5 沉积动力演化模型图

Fig.5 Schematic diagram of the sedimentary dynamic evolution model (a)NHD;(b)DTSD

参考文献 28

[1]	COSTANZA R, D’ARGE R, DE GROO T R, et al. The value of the world’s ecosystem services and natural capital[J]. Ecological Economics, 1998, 25(1): 3-15. DOI URL
[2]	郭菊兰, 朱耀军, 武高洁, 等. 红树林湿地健康评价指标体系[J]. 湿地科学与管理, 2013, 9(1): 18-22.
[3]	乔淑卿, 石学法, 王国庆, 等. 渤海底质沉积物粒度特征及输运趋势探讨[J]. 海洋学报, 2010, 32(4): 139-147.
[4]	庞仁松, 潘少明, 王安东. 长江口泥质区18#柱样的现代沉积速率及其环境指示意义[J]. 海洋通报, 2011, 30(3): 294-301.
[5]	宗娴, 石学法, 葛晨东, 等. 日本海百年来沉积速率及粒度指示意义[J]. 沉积学报, 2016, 34(3): 516-522.
[6]	朱士兵. 强台风“山竹”作用下南三岛海滩表层沉积物变化研究[M]//中国海洋工程学会. 第十九届中国海洋(岸)工程学术讨论会论文集(下). 呼和浩特:中国海洋工程学会,中国海洋学会海洋工程分会, 2019:165-172.
[7]	LI X B, SUN X Y, YUN H M, et al. Numerical study of the Donghai Dam impact on the hydrodynamic environment of Zhanjiang Bay[J]. Marine Science Bulletin, 2010, 12(1): 16-29.
[8]	陈碧珊, 陈诗敏, 何炽鹏. 雷州半岛红树林湿地表层沉积物粒度分布特征[J]. 现代地质, 2019, 33(1): 198-205.
[9]	张义丰, 贾大猛, 谭杰, 等. 海湾型城市定位对湛江城市发展的影响分析[J]. 自然资源学报, 2010, 25(1): 1-11.
[10]	李涛, 李团结, 陈亮, 等. 湛江海区海岛潮间带表层沉积物特征及对沉积环境的指示[J]. 海洋科学, 2012, 36(4): 113-120.
[11]	张际标, 姚兼辉, 陈春亮, 等. 湛江东海岛潮间带表层沉积物粒度的分布及与环境要素的相关性[J]. 应用海洋学学报, 2015, 34(1): 49-56.
[12]	SANCHEZ-CABEZA J A, RUIZ-FERNÁNDEZ A C. ²¹⁰Pb sediment radiochronology: an integrated formulation and classification of dating models[J]. Geochimica et Cosmochimica Acta, 2012, 82:183-200. DOI URL
[13]	FOLK R L, WARD W C. Brazos River bar: a study in the significance of grain size parameters[J]. Journal of Sedimentary Research, 1957, 27(1): 3-26. DOI URL
[14]	赵红梅, 刘林敬, 赵华, 等. 滹沱河古河道剖面粒度参数特征及沉积环境[J]. 现代地质, 2016, 30(2): 485-492.
[15]	孙华杰, 臧淑英, 孙德尧, 等. 呼伦湖沉积物粒度特征及其环境指示意义[J]. 地理科学, 2018, 38(9): 1570-1578.
[16]	许艳, 王拓夫. 湛江红树林保护区现代沉积物粒度特征及其对风暴事件的响应[J]. 台湾海峡, 2011, 30(2): 269-274.
[17]	钟和贤, 黄磊, 崔兆国. 南海西北部海域表层沉积物粒度分布特征及其影响因素[J]. 海洋地质前沿, 2013, 29(11): 22-31.
[18]	赵绍华, 许江, 房旭东, 等. 闽北近海柱状沉积物粒度特征及沉积速率研究[J]. 台湾海峡, 2012, 31(2): 277-285.
[19]	李国杰, 胡建平. 湛江东海岛近岸潮流场数值模拟[J]. 水道港口, 2007, 28(5): 325-330.
[20]	李志强, 谢石昌, 张会领, 等. 湛江市观海长廊红树林种植对岸滩影响初步研究[M]//中海海洋工程学会.第十四届中国海洋 (岸)程学术讨论会论文集(下).呼和浩特:第十四届中国海洋(岸)工程学术讨论会, 2009:757-759.
[21]	赵冲久. 湛江湾水文泥沙特性分析[J]. 水道港口, 1999, 20(4): 16-21.
[22]	林迪洋. 湛江湾填海工程的水动力条件影响及泥沙冲淤预测[D]. 青岛:中国海洋大学, 2005:50-51.
[23]	张海鹏. 《南三岛志》序[J]. 中国地方志, 2004, 24(3): 31-33.
[24]	陈同庆. 深入实施港口经济发展战略加速湛江现代化建设进程[J]. 广东党史, 1996(增): 4-7.
[25]	陆巍峰. 广东省湛江市区地质灾害现状的探讨[J]. 西部探矿工程, 2007, 19(2): 97-100.
[26]	唐晓春, 刘会平, 潘安定, 等. 广东沿海地区近50年登陆台风灾害特征分析[J]. 地理科学, 2003, 23(2): 182-187.
[27]	邓培雁, 刘威. 湛江红树林湿地价值评估[J]. 生态经济, 2007, 23(6): 126-128.
[28]	张志飞, 诸裕良, 何杰. 多年围填海工程对湛江湾水动力环境的影响[J]. 水利水运工程学报, 2016, 38(3): 96-104.