基于MLP方法的长江-洞庭湖江湖水沙交换演变规律研究  

Preliminary study on evolutions of Yangtze River and Dongting Lake water and sediment fluxes exchanges based on MLP method

作　　者：贾雅兰 施勇[1] JIA Yalan;SHI Yong(Nanjing Hydraulic Research Institute,Nanjing 210029,China)

机构地区：[1]南京水利科学研究院,江苏南京210029

出　　处：《水利水运工程学报》2020年第5期24-32,共9页Hydro-Science and Engineering

基　　金：国家重点研发计划资助项目(2017YFC0405301);中央级公益性科研院所基本科研业务费专项资金(Y520012)。

摘　　要：基于多层感知机MLP(Multi-layers Perceptrons)方法建立了长江和洞庭湖水沙交换关键节点间的回归关系,计算并分析江湖水沙交换各节点的联动变化。研究结果如下:(1)城汉河段(城陵矶-汉口)的河床冲淤及水情变化是江湖水沙通量演变的重要环节,分析下荆江裁弯后三口和干流水沙通量的变化可知,城汉河段淤积严重导致荆江水沙下泄受阻;(2)三峡水库运用后,荆江河段上下游间、主支汊间的水沙联系减弱明显;(3)当汉口水位高于26 m时,汉口水位每抬升1 m对应的螺山流量增量基本稳定,该值在调弦口建闸前后、裁弯后、葛洲坝截流后和三峡水库运用后分别为4400,4300,4500~4700和4000 m^3/s;(4)荆江三口水沙分泄能力对宜昌站来水量的响应程度逐渐减弱,在三峡水库运用前各时段内,三口水沙分泄能力对来水量的响应程度在汛期宜昌站流量站流量为35000 m^3/s时最强,三峡水库运用后,则是在汛前和汛后宜昌站流量为25000 m^3/s时最强。This study establishes the regression relationship among key nodes of water and sediment exchange in the Yangtze River and Dongting Lake on the basis of MLP(Multi-layers Perceptrons)method and calculates and analyzes the linkage changes of nodes between the Yangtze River and Dongting Lake.This study draws the following conclusions:(1)Analysis of changes of water and sediment flux in the three outlets and the main stream after Jingjiang artificial cut off shows that the riverbed erosion and water regime change in the Chenghan River section is one of the most important links in the water and sediment flux evolution of the Yangtze River and Dongting Lake.The serious sedimentation of the Chenghan River section leads to the discharge of water and sediment in Jingjiang blocked.(2)After the application of the TGP(Three Gorges Project),the flow and sediment relations between the upper and lower reaches,the mainstream and tributaries of the Jingjiang are weakened in a relatively prominent degree.(3)When the water level of Hankou is higher than 26 m,the flow increase of Luoshan is basically stable when the water level of Hankou has a rise of 1 m.The stable value is 4,400 m^3/s,4,300 m^3/s,4,500~4,700 m^3/s and 4,000 m^3/s respectively before and after the sluice construction of Tiaoxian outlet,after the Jingjiang cut off,after the interception of Gezhouba and the operation of the TGP.(4)The response of water and sediment discharge capacities of the three outlets of Jingjiang to Yichang's inflow is weakened gradually.During time intervals before the application of TGP,the response of water and sediment discharge capacities of the three outlets to Yichang's inflow is the strongest when the water discharge of Yichang is 35,000 m^3/s in the flood season.After TGP is applied,the response is the strongest when the water discharge of Yichang is 25,000 m^3/s before and after the flood season.

关 键 词：江湖水沙通量 水沙关系 荆江口 分流分沙 三峡工程 

分 类 号：TV142[水利工程—水力学及河流动力学]