网格尺寸对顺直河段计算冲淤量的敏感性分析  

Influence of grid dimensions on erosion-deposition amount by grid method in straight channels

作　　者：元媛[1] 张小峰[1] 段光磊 

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072 [2]长江水利委员会水文局荆江水文水资源勘测局,湖北荆州434020

出　　处：《泥沙研究》2014年第2期55-61,共7页Journal of Sediment Research

基　　金：国家自然科学基金项目(51079104);中央高校基本科研业务费专项资金(2012206020211)

摘　　要：在实测1∶10000河道地形图上采用网格法进行冲淤量计算时,不同网格尺寸会得到不同结果。以往对这个现象的关注和研究较少。本文计算了三峡坝下游镇江阁-万寿桥顺直段和古老背顺直段两个河段不同网格尺寸下2002年10月至2008年10月河道冲淤量,并通过概化地形,探讨了顺直河道中网格法冲淤量对网格尺寸的敏感性。分析表明:冲淤量随着网格尺寸的变化而变化,对该因素是敏感的,且敏感性与网格尺寸有关。网格尺寸较大时,不同尺寸计算得到的冲淤量波动较大,敏感性大;网格尺寸较小时,不同尺寸计算得到的冲淤量比较稳定,波动较小,敏感性小。但是,与根据地形图上实测的各施测断面位置切割断面得到的断面法冲淤量计算值对比发现,差异百分比的最小值并不出现在小网格尺寸时;当顺水流及河宽方向的网格尺寸分别与河道水下地形测验断面间距和测点间距最为接近时,网格法计算得到的河道冲淤量与断面法的差异才是最小的。Based on 1：10000 river course topographic maps, the grid method could be used to calculate the a- mount of channel erosion and deposition. But the fact is that different results will be gotten with different grid dimensions. This has not been received much attention. This paper calculates amounts of river channel erosion and deposition in two reaches in the Yangtze River, Zhenjiangge-Wanshouqiao reach and Gulaobei reach, from October 2002 to October 2008. Different grid dimensions were set in the application of the grid method. The relation between grid dimensions and calculation error is discussed on the basis of generalized channel topogra- phy. The research shows that the amount of river channel erosion and deposition calculated by the grid method in different grid sizes has big fluctuation when the grid size is large. The amount of river channel erosion and deposition tends to he stable and has tiny fluctuation when the grid size is small. But the minimum calculation error doesn＇t appear in the small grid size. The calculation error is rather small when the grid dimensions are most close to the section spacing and survey point spacing of underwater topographic survey in the longitudinal and transversal directions, respectively.

关 键 词：河道冲淤量 断面法 网格法 长江河道 水下地形测量 

分 类 号：TV148[水利工程—水力学及河流动力学]