| Qingdao Wangquan Reservoir, which is located at the upstream of Lianyin Riverin Jimo City, is an important source of freshwater for local urban water supply,agricultural irrigation as well as freshwater aquaculture. However, the water qualityand safety issues of the reservoir have become increasingly prominent because of theinfluence of local economic conditions, geological conditions as well as outsidesources of pollution. Base on the full grasp for natural geographical overview, generalengineering situation, environmental status and socio-economic status of the reservoirarea, the reservoir water was monitored, and representative water samples andsediment samples were collected at the same time to determine seasonal variations ofwater quality and sediment quality. For different indicators of water quality, themethod of single-factor evaluation is used to determine the relationship between theevaluation factors and standards, which directly reflect the compliance status of eachfactor. On this basis, reasonable distribution of the weight is realized by using fuzzyevaluation in order to comprehensively evaluate the water quality, trying to minimizethe impact of the fuzzy boundaries of the evaluation criteria and monitoring error ofthe evaluation results. In addition, the organic index method is used to evaluate thenutritional level of the sediment, while the accumulation index method and thepotential ecological risk index method is used to evaluate the degree of heavy metalcontamination of the sediment. Through monitoring and evaluation of the waterquality and sediment quality of the reservoir, the conclusions are as follows:(1)Based on the monitoring results of water quality of the reservoir in differentwater seasons, the pollute status of the reservoir is determined. The results showed,water quality changed over time, in higher water season, the concentrations of Fe, Mn,TN, TP were higher than the level in common and lower water season.Distribution ofwater quality in vertical direction showed a significant rule, in higher water season, temperature stratification occurred, the concentrations of NH4, Fe,Mn in bottomwater increased.(2)The concentrations of TN, TP, Fe and Mn in sediment were high, there waslitter change in different water seasons. The content of FE, Mn, NH4, TN ininterstitial water in sediment changed with water seasons, the concentrations weregreater in higher water season than in common and lower water season.(3)Different evaluation methods showed different results of water quality.Basedon grade â…¢in “Environmental quality standards for surface waterâ€,the results ofsingle factor evaluation showed that water quality of the reservoir is Grade â…¤, â…¤andâ…£ respectively in higher, common and lower water reason. Theresults of fuzzycomprehensive evaluation method is better than single factor evaluation, the level ofsurface water was Grade â… in different water seasons.(4)The results of organic index evaluation method showed that organic pollutionof the sediment of Wangquan Reservoir belonged to the class â…¢, organic nitrogenpollution belonged to class â…£. Index of Geoaccumulation indicated that themanganese pollution of the sediment was class â…¡in higher water season, and theindex in B2was the biggest, manganese pollution belonged to class â…¢. The results ofEcological risk assessment illustrated that manganese pollution of reservoir sedimentwas very low. |
