契爷石水库水质监测评价及水质预测研究

Study on Water Quality Monitoring Evaluation and Water Quality Prediction of Qiyeshi Reservoir

契爷石水库开展了6年(2015—2020年)的水质监测。结果表明:溶解氧、高锰酸盐指数、日生化需氧量和氨氮表现出明显的季节性变化特征,而总氮和总磷没有表现出明显的季节性特性;溶解氧随年份呈先减小后增大规律,高锰酸盐指数和五日化学需氧量没有明显规律性,氨氮、总氮和总磷在整体上呈递减趋势;采用综合水质评价法和模糊综合评价法对水库水质进行综合评价,评价结果均达到生活用水和灌溉用水要求的最低Ⅲ类标准;GM(1,1)灰色预测模型对水库水质指标的平均预测误差为9.8%,预测效果较好,可用于该水库未来一段时间内水质的预测分析。

The water quality is monitored in Qiyeshi Reservoir from 2015 to 2020 for 6 years.The results showthat dissolved oxygen,permanganate index,daily biochemical oxygen demand and ammonia nitrogen have obvious seasonal variation characteristics,while total nitrogen and total phosphorus have no obvious seasonal characteristics.Dissolved oxygen is decreased firstly and then increased with year.Permanganate index and 5-day chemical oxygen demand have no obvious regularity.Ammonia nitrogen,total nitrogen and total phosphorus have a decreasing trend asa whole.The comprehensive water quality assessmentmethod and fuzzy comprehensive evaluation method are used to comprehensively evaluate the water quality of the reservoir.The evaluation results all reach the lowest class III standard for domestic water and irrigation water.The average prediction error of GM(1,1)grey prediction model for the reservoir water quality index is 9.8%.The prediction effect is good.The research can be used for the prediction analysis of the reservoir water quality in the future period.