Study On Water Pollution Control Of Dashahe Reservoir Based On

Dashahe Reservoir is the main drinking source of Kaiping city, shouldering the living water supply of Kaiping city and towns along the water pipe with a total of nearly 380000 people. In recent years, because of more and more human activities, productions and operations surrounding Dashahe Reservoir area, dosage of chemical fertilizers in the catchments area are increased. Large livestock farms successively appear, the pollutants are discharged into the reservoir with the surface runoff directly, which will cause many water quality problems for Dahshahe Reservoir such like eutrophication trend.This paper, which is on the basis of GIS and SMS, focus on the analysis of water pollution control. The research contents and conclusions are as following:1. This paper uses GIS establishes a geographical spatial database of Dashahe Reservoir. The geographical spatial database provides an intuitively presentation of the data of terrains, drainages, sewage outlets, monitoring points and contamination distribution, which could query and manage the pollution.2. This paper uses the two-dimensional hydrodynamic model of RMA2 and two-dimensional water quality model of RMA4 to perform the simulation of Dashahe Reservoir. Through sensitivity analysis and rationality analysis, the paper calibrates the parameters of hydrodynamic force and water quality model and establishes the water quality model of Dashahe Reservoir. It will simulate the contaminant transport and diffusion rules in different hydrological conditions.3. Based on the pollutant concentration from water quality simulation- the response relationship of intake water quality, this paper uses the secondary development of ArcGIS to establish water quality analysis system and pre-warning system. Using RMA2 and RMA4 to track contamination intuitively and accurately, analyzing the influence of water pollution incident from the aspects of influence scope, influence degree and influence duration, etc. It ensures the water quality ore-warning and the safety and scientificity for Dashahe Reservoir water supply.4. This paper calculates the maximum allowable emission concentration and the total amount of pollutant of each incoming branch by water quality model. Taking the total nitrogen in drought period as an example, the model calculates the maximum load of each incoming branch, and assigns different allowable emissions in proportion to different tributaries: the maximum allowable emissions of Wojiang River is 1.595 mg/L, Fushi River is 0.735 mg/L, Shuangshi River is 1.1375 mg/L and Dasha River is 1.25 mg/L. Meanwhile, it calculates the different tributaries’ maximum allowable emissions of pollutants between drought period and wet season, the plentiful of, providing the basis for pollution reduction measures. From the maximum allowable emissions, it shows that in drought period, Wojiang River has the largest concentration of pollutant load, Baisha River and Dashahe River are the next, and Fushi River is the least; in wet season, Wojiang River has the largest concentration of pollutant load, and then Fushi River, Baisha River and Dahahe River. There is a conclusion from the total amount of pollutant: incoming branch pollutant load is greater in wet season than in drought period; keeping annual emissions unchanged, the water quality is worse in drought period than in wet season. Among these rivers, Fushi River has the worst pollutant load capacity. In order to ensure the water quality of inlet, Fushi River allows the least emissions of pollutants while Dashahe River allows the largest emissions of pollutants.5. This paper uses water quality model to calculate the cutting quantity pollutants of each incoming branch. According to the actual monitoring data, the total nitrogen concentrations of drought period and wet season should be cut to match the Standard GB3838-2002 class II. Comparing the maximum allowable emission concentration, reduces the tributaries storage pollutants.