Design Of Ecological Control Project For Small And Medium Rivers In Northern Mountainous Area

There are many small and medium rivers in our country and they are closely related to people’s production and life.The flood control safety is an important part of the river flood control system,and the ecological security of the river is an important part of the national ecological security.n northern mountainous areas,the river source is short,the flow is rapid and seasonal,and the flood control pressure is great in flood season,but the flow is often cut off in non-flood season.The ecological effect of many river channels is poor.Therefore,it is necessary to take into account the effects of flood control,ecology and landscape in the treatment,which undoubtedly increases the complexity of the control design.This paper takes the Mangniu River in Luanping County,Chengde City,Hebei Province as an example to study the ecological improvement project of mountain rivers and complete the following tasks:(1)Based on the investigation and analysis of hydrological,meteorological,flood and geological data of the river ecological control project of Mangniu River,the objectives and principles of ecological control are determined as follows:flood control and disaster elimination;ecology priority,close to nature;protection first,and proper consideration of development.(2)The traditional engineering design and ecological landscape elements are integrated,and the ecological landscape design along the river and important nodes is carried out at the same time of flood control engineering design.Then,the application of different materials and the selection of different engineering design schemes in the engineering design are comprehensively analyzed and compared in terms of flood discharge requirements,landscape effect,engineering safety and economic technology,and the engineering design scheme is optimized.(3)Based on Mike21,a two-dimensional hydrodynamic model of the designed river section is established to calculate the water level distribution and cross-section velocity field under the design conditions,which provides a fine guidance for the engineering design.(4)In the numerical simulation of the river channel,the landmark river sections with straight section,bifurcation section and bend section are selected to make the calculation results more representative.It provides a more precise calculation method for the hydraulic calculation of mountainous rivers with complex topography.The design concept and design method integrating engineering safety and landscape ecology is an effective means to implement river regulation and create a river space with"smooth river,clear water,green bank and beautiful scenery".Through the study of establishing two-dimensional hydrodynamic model for flood numerical model,this paper explores feasible methods for hydraulic calculation and engineering design optimization of complex mountainous rivers.