Study Of Water Quality Changes And Pollution Sources Survey Analysis Of Fengjiashan Reservoir

Fengjiashan reservoir is located in the downstream of Qianhe which is the secondarybranch of Yellow River,It's controling basin area is about3232km2accounts for93%of thetotal area.Fengjiashan reservoir is major in industry, agriculture, the urban water supply,incorporated with flood control, power generation, and cultivation.It's a large comprehensivefunction water conservancy project,is the mainly surface water supply source of Baoji and thewestern area.How to use and protect the water resources of Fengjiashan reservoir effectively,research the water quality change rule, and analyse the reasons are very important.According to the actual conditions, this paper through research reservoir water quality,sediment pollution condition of the bottom of the reservoir and the basin pollution situation tounderstand reservoir pollution situation, analysis pollution source and its change rule. Theseresearch could provide some theoretical basis for the future management and control work.Fengjiashan reservoir water quality monitoring series2004-2009shows that the waterquality is suit to the II standards. The author set section at Fengjiashan reservoir in April2011,and collect water and mud sample.The result shows that the reservoir water qualityindexes has attenuation trend from the river mouth to the front of the dam. Influence by runoff,water quality in flood season better than others.,and the concentration of the pollutantsdecreases with the runoff. Kendall rank times shows that the key pollution indicators CODand NO2-N are marked down,so the water environment and pollution control have goodeffects to the reservoir water quality protection.According to the monitoring of sediment results, reservoir sediment samples mostlydense texture is yellow, sticky clamp silty clay; Zn, Cr, Cu, Pb content average valueswere0.66mg/kg,17.19mg/kg,2.02mg/kg,14.70mg/kg,all of them within the soil environmentquality standard. the Zn, Cr, Cu; longitudinal distribution regularity is obvious, as the waterflows along the path of purification and sedimentation, sediment heavy metal contentdecreased, in front of dam content is almost the least.For further understanding Fengjiashan Reservoir Sediment Pollution, this paper applygeoaccumulation index and ecological risk index method to evaluation heavy metals insediment at the bottom of the reservoir. The results showed, in Fengjiashan Reservoir sediment accumulation index of less than0, no pollution, the pollution order:Pb> Cr> Cu>Zn; heavy metal potential risk factor is far lower than the minimal ecological pollution limits40, belong to no pollution risk, the risk degree of heavy metals were as follows: Pb> Cr> Cu> Zn.The reservoir protection is good, not allowed to directly discharge pollutants, so thereservoir mainly pollutants from its confluence area of Qianhe. the reservoir upstream rivermain stream of14sections water quality is monitored, with the single factor evaluation,comprehensive water quality assessment and water quality fuzzy evaluation method forcomprehensive analysis and evaluation, the results showed:Qianhe water quality is good. Inthe comprehensive assessment of water quality in most section, belonging to a cleaning andcleaning, only four section water quality belong to light pollution, they are: Qianyang Countyliving sewage outfall, Datang Power Plant, Longxian, Qianyang downstream the riverdownstream. On the water quality fuzzy evaluation, the four section water quality is poorer,its water quality categories are: III, IV, IV, III. In Section IV water quality and River RubberDam reach, but in the Nemerow comprehensive water quality assessment is relatively cleanwater. Therefore, the evaluating conclusion is same largely, but there are subtle differences,using water quality fuzzy evaluation method to evaluate the section water pollution moreserious.In CODMn, Cr⁶⁺, NH3-N as the main pollutants are analyzed, the monitoring sectionalaverage exceed the standard multiples are negative, Cr⁶⁺, NH3-N content is less, the CODMnisrelatively high, the main pollution section in between3-7, Longxian and Qianyang, threekinds of pollutants COD_Mn, Cr⁶⁺, NH3-N concentration big than the other section, CODMnhigh in Chencang. Analysis of the organic pollutants in the law, draw the conclusion: themaximum attenuation index is Cr⁶⁺, then CODMn, NH₃-N attenuation index is the minimum.