Research On The Simulation Of Pollutant Dispersion Based On Mike Model

Hanjiang River is the largest tributary of the Yangtse River.The water resources of the Hanjiang River are the basis for the sustainable development of the social economy in the middle and lower reaches of the Han River.With the rapid economic and social development and the construction of the Middle Route Project of the South-to-North Water Diversion Project,the carrying capacity of water resources in the middle and lower reaches of the Hanjiang River has become increasingly heavy and has become a bottleneck for regional economic development.Water resources have had a great potential crisis.Therefore,the study of the water environment in the middle and lower reaches of the Hanjiang River reveals the reasons for the impact of the water environment on regional sustainable development and explores the issue of regional sustainable development with certain practical significance.In view of the large pollution sources in the Hanjiang River Basin,the water quality problem has become a difficult problem to be solved.This paper collects hydrological site information,pollution source status,drainage companies,drainage outlets,topographic data of sections,and water quality of typical sections in the study area,and evaluates the hydrological and water quality characteristics of the studied river sections,and briefly analyzes the changes.The reasons for this,and based on the collected data,the establishment of river network files,cross-section files,boundary files,time series files,HD,AD parameter files,and adding these information to the simulation file,in order to establish hydrodynamic-water quality The mathematical model validates the applicability of the Mike model in the Hanjiang River Basin,predicts the water quality,and visualizes it in the GIS to more intuitively show the time and spatial variations of water quality.The following conclusions can be drawn from the simulation and algorithm calculation of the Mikell model:(1)In the hydrodynamic conditions,the river bed roughness is repeatedly determined,and the simulated and measured values are simulated well.Through repeated rate determination,the bottom of the river section is studied.The bed roughness is the Manning coefficient of 0.042 in the Xiang yang section and 0.022 in the Zhongxiang section.(2)In the mathematical model of water quality,the attenuation coefficient of the NH3-N in the Pu yang section is 0.217,the attenuation coefficient of the TP is 0.452,and the NH3-N in the Zhongxiang section.The attenuation coefficient is 0.164,and the attenuation coefficient of TP is 0.386.The simulation error of NH3-N in Shen wan Section is 25.6%,the simulation error of TP is 25.82%.The simulation error of NH3?N in the transition section is 29.24%.Simulation of TP The error is 26.42%,the maximum absolute error is 39.5%,and the overall average error does not exceed 30%;the model simulation is better;(3)The prediction time of the simulation calculation in this study is 2 hours,and the river length is predicted to be 30km in Zhongxiang.The predicted result is that NH3-N degrades 0.1952 mg/L in two hours,the concentration changes from 0.698 to 0.5028,and basically reaches the water quality secondary standard within 2 hours(NH3-N standard is 0.5 mg/L).After a change of 0.05h,0.4987 can be achieved.TP degraded 0.1339mg/L in two hours,and the concentration changed from 0.249 to 0.1151.Within 2 hours,the water quality could reach the secondary standard(TP standard was 0.1 mg/L).It took another 0.4h to reach the secondary level.Standard,the concentration is reduced to 0.0986.It is enough to show that the water quality of the Han River Basin is in good condition.It can provide a scientific basis for water quality management in the Han River basin.