摘要
以长江南京段为例,根据1984—2020年间Landsat卫星遥感影像资料,利用归一化差分水体指数法提取特定水位下的水边线,形态学方法提取河床边界和洲滩,本征正交分解法提取两者的时空演变特征。结果表明:近40年以来,长江南京段河床边界受人类活动影响向内收缩(对应水域面积减幅6%),并以长江村附近收缩最为剧烈,主要发生于1984—2005年;河段五大洲滩中,八卦洲、梅子洲及新济洲的形态变化较小,新生洲洲头消退和洲尾淤长程度相近,新潜洲自洲头向下游逐渐淤长,面积增幅200%,洲尾初期、中期及后期增长分别发生在1984—2000年、2000—2005年及2005—2020年。河床边界与洲滩时间序列的一阶模态反映了时均形态,其他高阶模态反映了局部冲淤消长规律,模态投影系数反映了各空间演变特征对应的时间演变特征。
With the development degree of river getting higher and higher,the negative accumulating effects are becoming serious.Evolution analysis results can provide basic support for scientific utilization,protection and management of rivers.Taking the Nanjing reach of the Yangtze River as a typical study case,the monthly Landsat remote sensing images from 1984 to 2020 were collected.The normalized difference water index method,the morphological method,and the proper orthogonal decomposition method were used to extract riverbed boundary and sands and their spatio-temporal evolution characteristics.Results show that in the past 40 years,the riverbed boundary of the Nanjing reach of the Yangtze River was shrunk by 6%due to human activities,and the most violent shrinkage,which occurred during 1984-2005,was near the Changjiangcun.For the five major sandbars in the Nanjing reach,Bagua Sandbar,Meizi Sandbar and Xinji Sandbar had little change;the eroding degree of the head of the Xinsheng Sandbar was similar to the deposition degree of its tail;while the Xinqian Sandbar was gradually deposited from the upstream to the downstream with an area increase of 200%,and the initial,medium and last stages of deposition were during 1984-2000,2000-2005,and 2005-2020,respectively.The first-order modes of riverbed boundary and sandbar series reflect the time averaged morphology,while other high-order modes reflect the erosion and deposition of local areas.Projection coefficient series can well depict the time evolution feature of the spatial evolution modes.
作者
杨志
董坤明
王珊
陈槐
王乃茹
范红霞
YANG Zhi;DONG Kunming;WANG Shan;CHEN Huai;WANG Nairu;FAN Hongxia(Anhui Modern Traffic Design and Research Institute Co.,Ltd.,Hefei 230011,China;Water Development Planning and Design Co.,Ltd.,Jinan 250100,China;Water Bureau of Jiangning District,Nanjing 210000,China;State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Nanjing Hydraulic Research Institute,Nanjing 210029,China)
出处
《水利水运工程学报》
CSCD
北大核心
2023年第4期34-41,共8页
Hydro-Science and Engineering
基金
国家重点研发计划资助项目(2022YFC3204504)
国家自然科学基金资助项目(52179072,52209095)
南京水利科学研究院创新团队项目(Y220011)。
关键词
长江南京段
洲滩
Landsat卫星遥感影像
归一化差分水体指数
形态学方法
本征正交分解
Nanjing reach of the Yangtze River
sandbar
Landsat remote sensing images
normalized difference water index
morphological method
proper orthogonal decomposition
作者简介
杨志(1989-),男,河南南阳人,工程师,主要从事水利水运工程设计研究。E-mail:584190248@qq.com。
