Study On The Accidental Water Pollution Events Simulation And Emergencg Management In Zhangze Reservoir

Water resources are the natural resources on which humans depend.China is a country with a shortage of water resources and frequent floods and droughts,especially in many arid regions of northern China.In recent years,emergent pollution accidents have occurred in China,and rivers,lakes and reservoirs have been polluted to varying degrees,and water quality safety issues have also become increasingly prominent.As far as the current research is concerned,the research on emergent pollution accidents at home and abroad is mostly concentrated in lakes,rivers,etc.,and little research on reservoirs is rare.Located in Changzhi City,Shanxi Province,Zhangze reservoir is a large(two)type reservoir with industrial,urban water supply,irrigation and flood control,taking into account the comprehensive utilization of farming and tourism.Due to the large number of upstream industrial enterprises and the complicated surrounding roads,once the industrial enterprises and traffic roads around the reservoir have emergent pollution accidents,they will be continuously discharged into the reservoir and be polluted to varying degrees,causingwater quality safety problems,safety for people create a threat.Therefore,it is necessary to study the emergent pollution accidents of the reservoir,simulate it and propose corresponding emergency measures.This paper takes Zhangze reservoir in Changzhi as the research object,and conducts on-the-spot investigation and survey of industrial enterprises in the upstream and surrounding reservoirs through the relevant materials,grasps the surrounding environment,identifies the sources of risks,and determines the fixed risk sources and mobile risks in the upstream and surrounding areas,and then construct a two-dimensional hydrodynamic-water quality coupling model.The scenario analysis method is used to set up various scenarios for different risk substances,and the migration and diffusion laws of pollutants are simulated and studied.When a emergent pollution accident occurs,it will formulate corresponding emergency management measures to minimize losses.The main research results are as follows:(1)Zhangze reservoir in Changzhi belongs to the reservoir in the arid area of northern China.According to the features of reservoir flow characteristics and movement modes,a hydrodynamic-water quality coupling model is constructed by a systematic scientific method,which can qualitatively and quantitatively simulate emergent pollution accidents.(2)On-the-spot investigation and research of the upstream and surrounding environment of the Zhangze reservoir,on the basis of understanding the environmental profile,identify the source of environmental risks,and identify the fixed risk sources and mobile risk sources in the upstream and surrounding areas.The fixed risk sources are mainly upstream of the reservoir,including industrial enterprises in the surrounding areas;mobile risk sources are mainly traffic risk sources,that is,traffic accidents caused by transportation vehicles on the surrounding traffic roads.(3)On the basis of fully understanding the actual terrain,the simulation scope is determined to be the entire water area of the reservoir area.The coordinates of the edge of the reservoir are determined by GPS site location,and the reservoir is digitized to determine its water-land boundary.Using the triangle grid system simulation,the reservoir area is generalized,and the water depth planographic topographic map is finally generated by digital processing technology;and the corresponding rainfall,evaporation,wind speed and wind direction time series files are generated,and the hydrodynamic-water quality coupling model is established.(4)Simulation of emergent pollution accidents,including hydrodynamic simulation and water quality simulation.For different risk substances,a variety of scenarios were set up to simulate the migration and diffusionof pollutants.Analysis and comparison of the simulation results,and get the following conclusions:(1)When the initial concentration of pollutants,wind power(wind speed and wind direction),discharge inlet and other factors are the same,the leakage time of pollutants increases,the corresponding diffusion area does not change,but the over-standard area increases,that is,the diffusion range of pollutants does not change,but the over-standard range is increased.(2)When the initial concentration of pollutants,the type of event emission,and the emission inlet are the same,the wind direction determines the diffusion path of the pollutants.When the wind speed is constant,compared with Dongfeng,the pollutants in the northeastern easterly wind diffuse downwards slowly;when the wind direction is constant,the wind speed increases,the pollutant diffusion area and the over-standard area also increase,and the pollutant diffusion range also increases.(3)When wind power of the pollutant(wind speed and wind direction),event emission type,discharge inlet and other factors are the same,the diffusion range,the over-standard range of the pollutants,and the concentration change values of pollutants at each cross-section simulated under each scenario are no matter which risk substance,it is only related to the initial concentration of the pollutant.(4)When the pollutant wind power(wind speed and wind direction),event emission type,discharge inlet and other factors are the same,theinitial concentration of pollutants increases,the diffusion area of the pollutants will not change,but the over-standard area will increase;that is,the initial concentration of pollutants changes,it does not affect its diffusion range,but it will change the range beyond the standard.(5)Research on emergency management measures for emergent pollution accidents.First,according to the principle of emergency monitoring,develop emergency monitoring plans and methods,and supervise and manage them,and then formulate emergency response measures.Once a emergent pollution accident occurs,it can be guided according to its emergency disposal measures.