Study On Interconnected River Network System And Hydrodynamic Water Environment In Haikou City

River system is the soul of the city and the lifeblood of urban development.With the rapid development of the social economy,urbanization and industrialization have been advancing rapidly,which leads to continuous expansion of urban areas.The problems of atrophy of rivers and lakes,poor connectivity of water system and degeneration of river function are becoming more and more severe.Based on the actual investigation and study of water system,resources and environment conditions and the connectivity of water system in Haikou City,the main problems existing in the connection of rivers and lakes and water environment in Haikou City were analyzed and summarized.Under the principle of respecting the natural distribution characteristics of river and lake water system,minimizing the manual intervention and large-scale adjustment,this paper constructed the hydrodynamic water quality model of central city and Jiangdong Group in Haikou.The hydrodynamic water quality characteristics of rivers and lakes in Haikou were analyzed and calculated and the effect of water quality improvement was predicted.The research contents and main conclusions are as follows.(1)This paper summarized the connotation,function and characteristics of rivers and lakes connectivity,sumed up the research progress of the development of rivers and lakes connected engineering development and hydrodynamic water quality model at home and abroad.(2)This paper introduced the basic situation of Haikou,including the distribution and basic characteristics of water system such as natural geography hydrology,meteorology,social and economic,key rivers,lakes and reservoirs,which can help lucidly understanding the present situation and pattern of river water system connectivity in Haikou.This paper discussed the main problems of water environment in Haikou and summarized the reasons and measures for the problems.(3)The basic principle,control equations and numerical solution of MIKE11,MIKE21hydrodynamic and water quality modules were studied.Meanwhile,it laid a theoretical foundation for the construction of the hydrodynamic water quality model,the design of the program,and the simulation of the central city and the Jiangdong Group.(4)The hydrodynamic water quality model in central city of Haikou was established,18 kinds of flow combinations under two operating conditions were analyzed and simulated.The results showed that the river-lake connectivity project can improve the water flow in both rivers and lakes,and increase the water environment capacity of rivers and lakes,leading to an obvious water quality improvement effect.It can play a technical support role for the future water environment treatment in Haikou City.(5)The hydrodynamic water quality model of Jiangdong Group was established,24kinds of flow combinations under two operating conditions were analyzed and simulated.The results showed that the high tide period should be avoided during the spring tide of the dry season,and the intermittent connection mode should be adopted.During the low tide of the dry season,the scheme of flow rate of 2 m~3/s into Daomeng river and 3 m~3/s into Maiya river can be selected to implement continuous connection to ensure the good effect of rivers and lakes connectivity to improve water environment.