The Numerical Simulation Of1-D And2-D On Nandu River And Floodplain

China is not only the one of countries with a high frequency of floods, but alsosubjected to the flood’s disasters. Because flood management is not enough perfect,flood risk of people is relative weak, the population is densely populated, when thereis flood, it causes a loss to human and property.How to plan to manage water resource. How to calculate the water level of riverand lakes accurately. How to evaluate the effect about flood on hydraulic structures(bridge). How to predict the path of the flood plain, All of those are the primary tasksfor flood.The reach length between the highway bridge of the Yongfa town and theLongtang hinge is about44km. the left bank of the reach is flood plain. The area offlood plain is so low-lying that a cloud of area of farmland and villages is submerged.In2011, Haikou government carries out important engineering project of Nadu riverbasin about the downstream. The flood control plan of Nandu river is fundamentalguarantee about this plan.This article establishes one-dimensional model between the highway bridge ofthe Yongfa town and the Longtang center. Firstly,the article builds the numericalsimulation of1-D of MIKE11HD and HEC-RAS, secondly it makes a comparison aboutdifferent models. It analyses the calculation principles of models, so can summary thebetter result. When we calculate the river flood, firstly we select the suitable models,then we make a comparison about the model’s results; secondly our project adopt therational result.Bridge has influenced on the flood of river, especially in flood season. In2013,there is a series of unfortunate events of bridge. This article summarizes the methodsabout the length and height of backwater. Moreover this article makes a comparisonabout those equations. This article takes the example of high way bridge of Nanduriver: firstly it builds the numerical simulation of1-D of bridge; secondly as we allknown, the region near the bridge has chaotic flow field, this article establishes thetwo-dimensional model to analysis the change around the bridge.The reach length between the highway bridge of the Yongfa town and theLongtang center is about44km. the left bank of the reach is flood plain. When itstorms, the left bank basin was destroyed seriously. This article establishes two-dimensional model depended on shallow water equations. It takes use of difference grids to subdivide the model. For roughness of the region, it put difference value todifference geomorphology depend on relevant standards. This model can simulate thesubmerged area, the submerged depth, the submerged flow rate about20years onceflood. This model can provide instructive for flood control.