Morphodynamics of an Artificial Cobble Beach in Tianquan Bay, Xiamen, China  

作　　者：SHU Fangfang CAI Feng QI Hongshuai LIU Jianhui LEI Gang ZHENG Jixiang 

机构地区：[1]College of Marine Geosciences, Ocean University of China, Qingdao 266100, China [2]Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, China [3]Island Research Center, Ministry of Natural Resources, Pingtan 350400, China

出　　处：《Journal of Ocean University of China》2019年第4期868-882,共15页中国海洋大学学报（英文版）

基　　金：supported by the Scientific Research Foundation of the Third Institute of Oceanography, State Oceanic Administration (Nos. 20170305, 2011010);the Public Science and Technology Research Funds Projects of Ocean (No. 201405037)

摘　　要：By tracking and monitoring the profile configuration, topography, and hydrodynamic factors of an artificial cobble beach in Tianquan Bay, Xiamen, China over three consecutive years after its completion, we analyzed the evolution of its profile configura- tion and plane morphology, and its storm response characteristics. The evolution of the profile configuration of the artificial cobble beach in Tianquan Bay can be divided into four stages. The beach was unstable during the initial stage after the beach nourishment the profile configuration changed obviously, and an upper concave composite cobble beach formed gradually, which was character- ized by a steep upper part and a gentle lower part. In the second stage, the cobble beach approached dynamic equilibrium with minor changes in the profile configuration. At the third stage the beach was in a high-energy state under the influence of Typhoon Meranti, and the response of the artificial cobble beach differed significantly from that of the low-tide terrace sandy beach. Within a short time, there was net onshore transport of cobbles in the cross-shore direction. The beach face was eroded, the beach berm was accumulated, and the slope of the beach was steepened considerably. In the alongshore direction, there was notable transport of cobbles on the beach from east to west along the shore, and the total volume of the beach decreased by 4.5×103 m 3, which accounted for 50% of the total amount of beach volume lost within three years. The fourth stage was the restoration stage after the typhoon, characterized by a little gentler profile slope and the increase in width and the decrease in height of beach berm. Because of the action of waves and the wave-driven longshore current caused by the specific terrain and landform conditions along the coast (e.g., coastal headlands, near-shore artificial structures, and reefs), the coastline of the artificial cobble beach gradually evolved from being essentially parallel to the artificial coast upon completion to a slightly curvedBy tracking and monitoring the profile configuration, topography, and hydrodynamic factors of an artificial cobble beach in Tianquan Bay, Xiamen, China over three consecutive years after its completion, we analyzed the evolution of its profile configuration and plane morphology, and its storm response characteristics. The evolution of the profile configuration of the artificial cobble beach in Tianquan Bay can be divided into four stages. The beach was unstable during the initial stage after the beach nourishment the profile configuration changed obviously, and an upper concave composite cobble beach formed gradually, which was characterized by a steep upper part and a gentle lower part. In the second stage, the cobble beach approached dynamic equilibrium with minor changes in the profile configuration. At the third stage the beach was in a high-energy state under the influence of Typhoon Meranti, and the response of the artificial cobble beach differed significantly from that of the low-tide terrace sandy beach. Within a short time, there was net onshore transport of cobbles in the cross-shore direction. The beach face was eroded, the beach berm was accumulated, and the slope of the beach was steepened considerably. In the alongshore direction, there was notable transport of cobbles on the beach from east to west along the shore, and the total volume of the beach decreased by 4.5×103 m^3, which accounted for 50% of the total amount of beach volume lost within three years. The fourth stage was the restoration stage after the typhoon, characterized by a little gentler profile slope and the increase in width and the decrease in height of beach berm. Because of the action of waves and the wave-driven longshore current caused by the specific terrain and landform conditions along the coast(e.g., coastal headlands, near-shore artificial structures, and reefs), the coastline of the artificial cobble beach gradually evolved from being essentially parallel to the artificial coast upon completion to a slightly curved para

关 键 词：BEACH NOURISHMENT COBBLE BEACH morphologic evolution erosion HOTSPOT storm response 

分 类 号：P[天文地球]