Numerical Studies On The Impact Of The Ecological Landscape Of Urban River On Flood Control

Nature gave birth to the river. The city was feed by the river which was born thecity’s aura and contain the history of the city. River is the important resources of a cityin the survival and growth. It is also a material carrier of cultural tradition to continue.Solving the current problem of rivers, thoroughly improving water quality, promotingwater circulation, enhancing the capacity of river flood control, building a beautifulwater environment of a city and to create a "clear water, green, landscape beauty" ofthe river ecological landscape are the important parts of a city construction. Thispaper takes Li Cun river as an example,and based on a large number of documents,through numerical simulation and physical experiment and research, combined withthe numerical analysis, fluid dynamics, sediment transport dynamics and othermultidisciplinary methods, starting from the analysis of different water landscape planduring the flooding velocity corresponding and hydraulic elements, the landscapedesign more reasonable, and the results of ecological landscape of different floodcontrol, because the scheme objectively consider the hydraulic condition and theinfluence factor, multiple results, numerical simulation and actual test model fit ishigh. It has high practical value and guiding significance.Based on the Li Cun River Gate, the vegetation and landscape island is a maininfluencing factors of water were analyzed, combined with the Licun Rivertopography, landforms, hydrological and meteorological data, given the specificnumerical simulation algorithm for dynamic analysis of environment. On this basis,the different results were compared, the water blocking effect of different riverlandscape scheme of water, resulting in the great differences between the water levelin the water under the same conditions and flow velocity.It can be seen on the basis of the numerical simulation,the roughness influencesthe highest flood level very much in the flood process.Roughness ont only influencesthe changeable area,but also the upstream and it has little affection to the downstream. The greater the roughness change, the greater the water level change.It’s suggestedthat river landscape is suggested to design as a streamline shape as far as possible,setting along with the flow direction to reduce the resistance to the flow; At the sametime, the aquatic vegetation of the landscape island should be given priority to theflexible vegetation, as it is easy to bending deformation under the action of largerflow rate when overflow and it could reduce the height of vegetation form and theadditional resistance. When plant vegetation on the shore slope, it is feasible tochoose herbaceous vegetation within the flood line, and choose tall shrubs outside theflood line, such conducing to overflow. Vegetation group has a strong resistance towater flow, the greater the roughness is, the greater the resistance would be. Thesmaller the velocity is,the higher the water level would be. The rangeability of flowrate various from different roughness,but it’s trend is the same. The greater theroughness is,thegreater it’s amplitude would be, and the more obvious the changesamplitude fluctuation would be. Flow is disorder in river bend, mainstream onconcave bank will continue scour at the bottom of the form scour on the concave bank,increasing the degree of bend in the river bend.It;s not avalible to release floodwater,along with increasing the contradiction between the water flow and bed. Thusthe dam line should be consistent with the river as far as possible, and try to keepparallel on both sides of the dam, avoiding the phenomenon of local suddennarrowing or widening.This is conducive to the flood.In addition, the small model for numerical simulation can be used to get therelationship between water level and river full, also can simulate the points speed,therefore we can analysis landscape plan of the flood control capacity. The method oflandscape flood analysis has a certain guiding role. The height of the island landscapechanging for the island had a greater influence on the upstream flow velocity.