亚热带中小型山溪性河流—宽陆架系统“源—汇”过程——以闽江—东海陆架系统为例  

“Source-to-sink”Processes of a Subtropical Mid-small Mountainous River-wide Continental Shelf System:A case study from the Minjiang River-east China Sea system

作　　者：王爱军 叶翔 徐晓晖 谢津剑 陶舒琴 赖志坤 吴水兰 杨雨欣 WANG AiJun;YE Xiang;XU XiaoHui;XIE JinJian;TAO ShuQin;LAI ZhiKun;WU ShuiLan;YANG YuXin(Laboratory of Coastal and Marine Geology,Third Institute of Oceanography,Ministry of Natural Resources,Xiamen,Fujian 361005,China;Fujian Provincial Key Laboratory of Marine Physical and Geological Processes,Xiamen,Fujian 361005,China;Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai),Zhuhai,Guangdong 519082,China;School of Civil Engineering,Fuzhou University,Fuzhou 350108,China;School of Marine Sciences,Nanjing University of Information Science and Technology,Nanjing 210044,China)

机构地区：[1]自然资源部第三海洋研究所海洋与海岸地质研究室,福建厦门361005 [2]福建省海洋物理与地质过程重点实验室,福建厦门361005 [3]南方海洋科学与工程广东省实验室(珠海),广东珠海519082 [4]福州大学土木工程学院,福州350108 [5]南京信息工程大学海洋科学学院,南京210044

出　　处：《沉积学报》2022年第6期1615-1634,共20页Acta Sedimentologica Sinica

基　　金：国家自然科学基金(41776099,41961144022);自然资源部第三海洋研究所基本科研业务费项目(海三科2017015,海三科2019018);南方海洋科学与工程广东省实验室(珠海)创新团队建设项目(311021004)。

摘　　要：中小型山溪性河流易受极端事件和人类活动影响,且对环境变化响应敏感,在大陆边缘物质循环过程中发挥着十分重要的作用,但学术界对它们的重视程度不够。以闽江—东海陆架系统为例,通过资料收集、遥感解译、样品采集与分析等方法,系统研究了亚热带中小型山溪性河流—宽陆架系统的“源—汇”过程。研究结果表明,人类活动引起的土地利用变化使得闽江入海径流量和泥沙通量在波动中略有增加,但水库的建设显著减少了入海泥沙通量,并且减弱了水沙通量的季节差异,河流入海泥沙通量变化对流域人类活动敏感且响应迅速;河口水体环境、悬浮体浓度、沉积物粒度组成及陆源有机碳埋藏的空间分布格局均显示,闽江入海泥沙主要分布在闽江河口附近海域,其中粗颗粒泥沙在水动力的作用下主要堆积在河口水下三角洲平原及前缘,细颗粒泥沙主要堆积在水下三角洲前缘斜坡及前三角洲附近海域,仅有少量细颗粒泥沙沿岸向外输运并沿途沉积,与大河流—宽陆架系统及中小型山溪性河流—窄陆架系统显著不同。河口人类活动及极端事件通过改变沉积物组成、环境动力、入海泥沙通量等方式对河流—陆架系统的“源—汇”过程产生显著影响。在当前流域来沙量锐减、河口地区海砂开采等人类活动强度增大的情况下,有必要加强相关研究。Mid-small mountainous rivers are vulnerable to extreme events and human activities and sensitive to envi⁃ronmental changes.They play an important role in the material cycling process on the continental margin.However,academic circles have not given this topic sufficient attention.Taking the Minjiang River-East China Sea continental shelf system as the target area,this study systematically examined the“source-to-sink”process of the subtropical mid-small mountainous river-wide continental shelf system through data collection,remote sensing interpretation,sample collection,and analysis.The results show that the land use change caused by human activities in the Minjiang River Basin slightly increased the runoff and sediment flux discharged into the sea,but the construction of the reser⁃voir significantly decreased the sediment flux and weakened the seasonal difference in the water and sediment fluxes.The variation of the sediment flux into the sea by the Minjiang River is sensitive to human activities in the basin and responds rapidly.The spatial distribution of estuarine water environment parameters,total suspended matter concen⁃tration,sediment composition,and terrestrial organic carbon burial patterns all show that the sediment entering the Minjiang River estuary was sourced near the Minjiang River estuary,of which coarse-grained sediment was accumu⁃lated in the subaqueous delta plain and front area of the estuary under the interaction of hydrodynamic processes,fine-grained sediment was accumulated in the subaqueous delta front slope of the prodelta,and only a small amount was transported and deposited along the coast.This differs significantly from the large river with a wide shelf system and the mid-small mountainous river with a narrow shelf system.Human activities and extreme events in the estuary and river basin have a significant impact on the“source-to-sink”processes of the river-shelf system by changing sedi⁃ment composition,environmental dynamic processes,and sediment flux discharged int

关 键 词：中小型山溪性河流 “源—汇”过程 人类活动 极端事件 闽江—东海陆架系统 

分 类 号：P512.2[天文地球—地质学]