摘要
近40年来,中国钦州湾和菲律宾马尼拉湾海岸线发生了显著变化,了解其变化规律对区域海岸带管理和规划具有重要意义。文章基于Google Earth Engine(GEE)平台,利用改进的归一化水体指数(Modified Normalized Difference Water Index,MNDWI)和大津(Otsu)算法,结合数字岸线分析系统(Digital Shoreline Analysis System,DSAS),对两地近40年的海岸线时空变化特征及其驱动因素进行分析。结果表明,1987—2022年,钦州湾海岸线长度增加了44.78 km,总体呈现向海推进趋势,平均变化速率达6.81 m/a,自然岸线占比不断下降而人工岸线比例上升。相比之下,马尼拉湾海岸线变化相对较小,总长度减少1.05 km,平均变化速率为2.36 m/a,自然岸线占比持续下降。钦州湾围填海强度指数和年均空间扩展速率均大于马尼拉湾。两地海岸线演变的特征均是受到围填海活动的显著影响,而港口码头建设和围海养殖是围填海的主要驱动因素。
Over the past 40 years,significant changes have occurred along the coastlines of Qinzhou Bay in China and Manila Bay in the Philippines.Understanding the patterns of these changes is important for the management and planning of coastal zones.This study is based on the Google Earth Engine platform,using the modified normalized difference water index,combined with the Otsu algorithm and the Digital Shoreline Analysis System,to extract the coastlines of Qinzhou Bay in China and Manila Bay in the Philippines over the past 40 years,and then analyze the spatiotemporal variation characteristics of the two coastlines and the situation of reclamation.The results show that in the past 40 years,the coastline of Qinzhou Bay has generally advanced towards the sea,with a coastline length increase of 44.78 km,an average End Point Rate(EPR)of 6.81 m/a,and average Linear Regression Rate(LRR)of 6.16 m/a.Natural coastline length continued to decrease,whereas the proportion of artificial coastlines continued to increase.The Index of Coastline Utilization degree(ICUD)values show an upward trend,whereas the Index of Coastline Type Diversity(ICTD)values show a continuously decreasing trend.The Manila Bay coastline first increased and then decreased,with an overall decrease of 1.05 km—a relatively small change.The coastline also shows a trend of advancing towards the sea with an average EPR of 2.36 m/a and average LRR of 2.32 m/a.The proportion of natural coastlines continued to decline,whereas that of artificial coastlines gradually increased.The ICUD values showed a steadily increasing trend,whereas the ICTD values showed a downward trend.The cumulative area of reclamation in Qinzhou Bay has reached 6,674.27 hm^(2),with an average annual expansion rate of 196.30 hm^(2)/a.Reclamation activities were significantly active and large-scale.However,the cumulative reclamation area of Manila Bay is only 1,718.59 hm^(2),with an average annual expansion rate of 50.55 hm^(2)/a,indicating relatively limited reclamation activities.The reclamation intensity index and annual spatial expansion rate of Qinzhou Bay were higher than those of Manila Bay.Overall,compared to Manila Bay,the Qinzhou Bay coastline exhibited more significant characteristics in terms of change amplitude,change speed,and reclamation intensity.Reclamation activities have a significant impact on coastline changes,and port and dock construction and aquaculture are the main driving factors for reclamation.
作者
张文良
郭俊丽
刘卓成
时连强
龚照辉
张达恒
Zhang Wenliang;Guo Junli;Liu Zhuocheng;Shi Lianqiang;Gong Zhaohui;Zhang Daheng(Research Center for Coast and Island,Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China;School of Geography and Ocean Science,Nanjing University,Nanjing 210023,China;Guangxi Key Laboratory of Beibu Gulf Marine Resources,Environment and Sustainable Development,Fourth Institute of Oceanography,Ministry of Natural Resources,Beihai 536000,China;Urban Planning&Design Institute of Shenzhen,Shenzhen 400020,China;Haikou Marine Geological Survey Center,China Geological Survey,Haikou 571127,China)
出处
《热带地理》
北大核心
2025年第3期489-503,共15页
Tropical Geography
基金
自然资源部专项业务费项目(CB202202015)
自然资源部第四海洋研究所基本科研业务费资助项目(202109)。
关键词
遥感
海岸线
围填海
钦州湾
马尼拉湾
remote sensing
coastline
reclamation
Qinzhou Bay
Manila Bay
作者简介
张文良(2000-),男,山东昌乐人,硕士研究生,主要研究方向为海岸带资源环境遥感,(E-mail)dixinzwl@163.com;通信作者:时连强(1977-),男,山东青州人,正高级工程师,主要研究方向为河口海岸过程与资源环境效应,(E-mail)lqshi@sio.org.cn。
