Study On Water Quality Simulation And Pollution Control At Fenhe Reservoir

The reservoir appeared and developed with people’s efforts to control the flood and store water. It plays an important role in regulating runoff, improving navigation, controlling flood, irrigation, hydraulic utilization, etc. With the development of human society and economics, the contradiction between the supply and the demand of industrial, agricultural and domestic use of water is becoming increasingly serious. Therefore, the function of reservoir water supply is becoming more and more important. However, the pouring of pollutants into the upstream and the nearby of a reservoir causes an increasingly prominent reservoir water environment problem, which not only raises the difficulty of water supply terminal water treatment technology and processing cost, but also makes it difficult to guarantee the safety of residents’usage of water. These become an obstacle for a reservoir to make full use of its function of water supply. Fenhe reservoir, as the largest surface water source of drinking water in Shanxi Province, and the centralized source of domestic drinking water in Taiyuan, the water quality is directly related to Taiyuan people’s health. Taking Fenhe reservoir hydrodynamics, contaminant transportation and dispersion and pollution control as the main research content, this paper applies the concept of the systematical engineering to the determination of technical route for this subject, adopting dimensional hydrodynamic model and water quality model to conduct the numerical simulation for the hydrodynamics and pollutant transportation and dispersion under different working conditions of the reservoir. When area percentage of pollutant concentration surpasses the standard at the field of the reservoir, the study suggests the method of reverse calculation to get the maximum of influx pollutant concentration. It can be directly applied in water quality management and it enhances the efficiency of water quality control and decision. The achievement of this research proves a general theoretical and practical significance.Main study results of this paper are:(1) From the analysis of geological model of reservoir nature information and the problem of hydrological water quality to the building of reservoir hydraulic model and water quality model which are regarded as a giant system, this paper systematically and gradually penetrate through the research of hydraulics and pollutants transportation and dispersion of Fenhe reservoir.(2) Study of HydrodynamicsBased on the practical condition of Fenhe reservoir and the field around it, the study works out the scale of simulation. Considering the natural structure of the reservoir, the study generalizes the grid system of the numerical simulation and the digital bathymetry, then, chooses and builds the dimensional hydrodynamic model for the reservoir under the triangle grid system. Utilizing this model in the separate research on influence factors for hydrodynamic conditions, this paper screens and fends out the key factor for the hydrodynamic condition.(3) The monitoring of practical condition of Fenhe reservoir and its upstream water qualityFor the deep understanding of the current situation of Fenhe water quality, the monitoring of Fenhe reservoir and its upstream water quality was conducted in2012in order to provide real data for simulating the pollutants transportation and dispersion and analyzing the effects of pollutants. Also, the monitoring of water quality of Fenhe reservoir and its upstream was conducted in April, May and July (representing dry season, level period and wet season respectively) to know the water quality of Fenhe reservoir and its upstream.(4) The research on pollutants transportation and dispersionBased on the dimensional hydrodynamic model, this paper sets up the model of pollutant transportation coupled with the former model. Then, the study independently simulates the conditions under every scenario with the latter model. With the analysis for the simulating result, the study discovers the rule of pollutant transportation under different weather and working condition of the reservoir.(5) Reverse calculation for the influx pollutant concentration Aiming at the problem of a great amount of pollutant concentration surpassing the standard in the field of the reservoir, the study proposes a new method for controlling water quality, which is reverse calculation for the influx pollutant concentration controlling based on the polluted basin percentage of the area where the pollutant concentration surpasses the standard, namely, the method of data fitting. With the calculated discrete points group of influx concentration and the related standard overwhelming area, the study works out the responsive relationship between the influx concentration and the standard overwhelming area percentage. The application of this relationship will be benefitial for the checking work of the influx pollutant controlled concentration that corresponded to the percentage of standard overwhelming in random area. According to such concentration value, the reduction plan for draining points on upper reaches can be further decided. In addition, the calculated response line can be used as a query tool serving the decision making of the water quality control for north mainstream project.This paper systematically analyzes the hydrodynamic characteristics and pollutant transportation and dispersion rules of Fenhe Reservoir, which provides a reference for the scientific utilization of the water resource and the pollution control of the reservoir. Also, it serves as a technical support for the engineering design and proposal option of the Yellow River Disposal Project.