GIS支持下长江口南支河道百年来的演变  

GIS-SUPPORTED ANALYSIS OF THE RIVER CHANNEL EVOLUTION OF SOUTH BRANCH IN THE YANGTZE ESTUARY FOR THE RECENT 100 YEARS

作　　者：胡红兵[1] 胡刚[2] 胡光道[1] 

机构地区：[1]中国地质大学资源学院数学地质与遥感地质研究所,武汉430074 [2]国土资源部青岛海洋地质研究所,青岛266071

出　　处：《海洋地质与第四纪地质》2008年第2期23-29,共7页Marine Geology & Quaternary Geology

基　　金：国家重点基础研究发展规划项目(2002CB412407)

摘　　要：利用长江口南支河道1900—2001年的5幅海图资料,在GIS的支持下,建立了百年来长江口南支河道的水下数字高程模型(DEM),在此基础上对其演变特征进行了计算和分析。结果表明:(1)1900—2001年间南支河道表现为微冲,不同时段的冲淤状况不同。(2)南支河道的冲淤演变主要表现为5个水道和4个成形沙体的冲淤变化,各水道的最大水深和成形沙体的总面积和总体积都呈不断增大趋势。(3)南支河道各主要断面以复式河槽为主,主槽位于南岸,且最大水深不断增大。位于南支河道入口处和出口处断面的变化比中段断面的变化剧烈。(4)南支河道的演变是自然演变和人工控制共同作用的结果。Quantitative analysis was performed on the evolution characteristics of the river channel of south branch in the Yangtze estuary for the recent 100 years with the help of GIS and DEM technology. Supported by GIS, five pieces of charts of south branch from 1900 to 2001 are digitized and digital elevation model （DEM） of south branch in different periods is established with Kringing gridding method, based on which the evolution of the river channel of south branch is visualized and the characteristics of erosion-accretion are calculated. The results show that （1） The river channel storage volume increased slightly at the annual average rate of 0. 027 × 10^8 m^3 , which coincided with the state of slight erosion of south branch at the annual average rate of 0. 033×10^8 m^3 of volume and 0.37 cm of thickness respectively from 1900 to 2001, and the states of erosion-accretion were different in different terms and different locations, scouring before 1958 and after 1979 whereas filling from 1958 to 1979. （2） The evolution of south branch was characterized by the changes of five channels and four shoals with the area and volume of shoals and the maximum of depth of channels increasing respectively. （3） Most of cross sections in south branch were double-entry channel and the master channels located at south bank. Changes of cross sections at the entrance and exit were more intense than that of counterpoints in the middle of south branch. （4） The effect of floodwater-building channels and different waterway between flood tide and ebb tide were the two major natural factors on south branch evolution, whereas its response to suspended sediment discharge from Yangtze drainage basin reflected the influence of human activities on its evolution.

关 键 词：河道演变 GIS 南支 长江口 

分 类 号：P737[天文地球—海洋地质]