Study On Water Quality Evaluation Methods And Design Of Lake Eutrophication Evaluation System

Economic development and industrial progress have led to social development,which has made people pay more and more attention to the prevention and control of freshwater pollution.The use of reasonable water quality assessment methods and the establishment of a stable and reliable water quality evaluation system is an important means for water pollution monitoring and management.This requires the study of water quality level monitoring and design of quantitative analysis software systems to the large-scale lake waters.In this paper,the complex mechanism of water pollution was quantified into some water quality parameters which have large correlation with eutrophication.Total nitrogen(TN),total phosphorus(TP),chlorophyll a(Chl_a),suspended matter(ss)and Permanganic acid(CODmn)as the research variables.Based on the evaluation criteria of domestic surface water and the research parameters of this subject,the reference standard of lake eutrophication evaluation was established,Comprehensive nutritional status index method(TLI),single factor evaluation method,fuzzy comprehensive evaluation method and BP neural network algorithm were used to evaluate the water quality.The key to the establishment of water quality evaluation system lies in the construction of water quality evaluation optimization model.From the point of merit,the results of the evaluation of the algorithm and the actual situation were compared and analyzed,and the BP algorithm was established as the original model of water quality evaluation and optimization.By using the ability of genetic algorithm to optimize the global optimization,to compensate for the difference between the initial weights of the BP algorithm and the uncertainty of the threshold,and the optimized GA-BP model is used to evaluate the water quality.Compared with the traditional BP neural network algorithm,it shows that hybrid GA-BP algorithm has obvious advantages in computational efficiency and evaluation precision.The optimized GA-BP model evaluates from 0.1 to 0.05,and the evaluation speed is faster 4 times.In order to construct a complete evaluation system,this project has designed a water quality evaluation system.The system functions include system login,multi-format inversion image with data,data preprocessing,data storage,data calculation,evaluation algorithm stable embedding and visualization of evaluation results.We Selected IDL development platform and IDL programming language for system development.The design process of the landing module and the evaluation module is introduced.The design of the UI interface of the water quality evaluation system and the layout of each menu bar are introduced in detail.At the same time,the system has been tested for functional and nonfunctional software.The system can accurately estimate the image quality of the five evaluation parameters in Longquan Lake,and then establish the quantitative evaluation system of water quality,and effectively monitor the large area water pollution.The research results has provided a reliable guarantee for the Chengdu Science and Technology Bureau of water quality monitoring technology research and development projects.