Optimization Of Drainage Scheme In Tongnan Area Of Taizhou

With the continuous development of economy,the problem of water resources has become an important factor affecting human survival and sustainable development.Due to the unbalanced distribution of water resources in time and space,the mismatch between natural water supply process and economic and social water demand,more and more problems such as frequent floods and droughts,intensified contradiction between supply and demand,etc.have become prominent.However,the improvement of people's living standards and the implementation of the national beautiful rural construction and Rural Revitalization Strategy have put forward higher requirements for regional water environment and water ecology.Therefore,it is necessary to improve the supply capacity of regional water resources,build a high standard flood and drought prevention system,and improve the water ecological environment to ensure the sustainable development of regional economy.This paper takes the economically developed Tongnan region of Taizhou as the research object,aiming at the characteristics of water demand and drainage in this region,it is of great significance to carry out the research on the regional drainage and drainage scheme aiming at the Yangtze river.Tongnan region of Taizhou is a densely populated region with high topography,crisscross river network and variable direction of water flow.The diversion water source and drainage outlet in this region are the Yangtze river,and the Yangtze river in this section is a tidal river.The tidal level of the Yangtze river varies greatly between years,and the regional drainage is affected by the tidal level change of the Yangtze river.The problems existing in the current drainage engineering include:(1)In terms of water diversion,artesian river diversion is the main form of water resources supply in the plain region.However,only relying on artesian river diversion,the irrigation guarantee rate is low,the water level is low,and the water supply is insufficient,which affects the sustainable development of the economy.(2)In terms of drainage,due to the delay in drainage project construction,the river system was not fully planned and arranged,resulting in messy drainage systems and low drainage standards in urban and rural regions.In addition,the drainage is often supported by the high water level of the Yangtze river,and the drainage capacity is limited,which increases the pressure of regional drainage.The effects of current landform water and industrial situation on economic development is analyzed by us.The results were as follows:(1)The characteristics of the tidal level of the Yangtze River and its influence on the regional drainage are analyzed.(2)According to the characteristics of crisscrossing river channels,slow flow rate and uncertain flow direction in plain river network region,the hydrodynamic model of river network was established,which laid a foundation for optimizing the effect of different water diversion schemes.(3)On the basis of analyzing the characteristics of water demand and drainage in the region,four feasible engineering schemes are proposed to solve the flood and drought disaster in the region.The initial conditions and boundary conditions are determined.The roughness parameters of the river network are determined.The unsteady flow dynamics model of the river network is used for numerical simulation.(4)Through the study of the water diversion and diversion scheme in Tongnan region of Taizhou city,it is determined that the best scheme is to implement the diversion and drainage project(stimulation port?anning port)in Tongnan region of Taizhou city.The scheme in 75%?95%reliability in the Yangtze river water,can increase the peaceful harbor lead river flow 28.6?28.7 m3/s,in late may to mid-june with can increase the river water from 438 to 3.98 million m3,raise Huang Qiao level 0.01?0.02m,significantly enhanced the ability to lead river,the drainage capacity of the region once every 20 years,irrigation drainage standard assurance rate reached 95%;It has improved the regional water resources allocation pattern and provided guarantee for the sustainable development of regional economy.