输沙量法与地形法估算河道冲淤量的对比研究  

Contrast study on Estimation of River Deposition-Erosion Amount by Sediment Budget Method and Morphological Change Method

作　　者：董耀华[1] 

机构地区：[1]长江科学院,武汉430010

出　　处：《长江科学院院报》2009年第8期1-5,共5页Journal of Changjiang River Scientific Research Institute

基　　金："十一五"国家科技支撑计划课题"三峡工程水库泥沙淤积及其影响与对策研究"(2006BAB05B02)

摘　　要：以长江中游荆江新厂至监利河段实测水沙与河道地形资料为基础,采用输沙量法与地形法,分别估算了1987年6月至1991年5月该河段的河道冲淤量,并初步对比分析了2种方法的差异、适用性与关键影响参系数。计算分析表明:①采用输沙量法,假设床沙质冲泻质分界粒径为0.0625 mm,1987年6月1日至1991年5月31日新厂至监利河段河道淤积量为0.431 4亿t;采用地形法,假设平滩水位为34.0 m,1987年5-6月至1991年5月该河段的河道淤积量为0.4383亿t。2个估算结果非常接近。②影响输沙量法的关键参系数为床沙质冲泻质分界粒径与悬沙级配;影响地形法的关键参系数为平滩水位与泥沙干密度。③在河道冲淤基本平衡和造床条件下,合理确定床沙质冲泻质分界粒径(输沙量法)和平滩水位(地形法),输沙量法与地形法估算的河道冲淤量可以一致或接近;偏离冲淤平衡与造床条件越远,2种方法的估算结果差异越大。Regarding Xinchang-Jianli reach of the Middle Changjiang Jingjiang River as an example, on the basis of field data of runoffs, sediment loads and morphologies of river channels, deposition-erosion amounts of Xinchang-Jianli reach from Jun. 1987 to May 1991 are estimated by sediment budget method and morphological change method. Difference, suitability and key influential parameters or coefficients of these two methods are preliminarily contrasted and analyzed. Main conclusions are as follow： （ 1 ） By means of sediment budget method and under separated sand size 0. 062 5 mm of wash load and bed material load, the deposition amount of XinChang-JianLi reach from 1st Jun. 1987 to 31st May 1991 is estimated at 0. 431 4 ×10^8 t, while by means of morphological change method and under bankfull stage of 34.0 m, the deposition amount of XinChang-JianLi reach from May -Jun. 1987 to May 1991 is estimated at 0. 438 3 × 10^8 t. , and two estimates are very close. （2） The key parameters or coefficients influencing sediment budget method are the separated sand size of wash load and bed material load and the suspended sediment grading curves, while those affecting morphological change method are the bankfull stage and the sediment dry density. （3） Under quasi-equilibrium of deposition-erosion and＇conditions of channel-forming, once the separated sand size of wash load and bed material load （ for sediment budget method） and the bankfull stage （ for morphological change method） are properly selected, deposition-erosion amounts estimated by both Methods can be obtained identical or very close, the more deviation from deposition - erosion equilibrium and channel - forming condition, the more different of resuits of these two methods.

关 键 词：河道冲淤 输沙量法 地形法 冲淤平衡 造床条件 床沙质冲泻质分界粒径 平滩水位 

分 类 号：TV143.4[水利工程—水力学及河流动力学]