义昌江流域水质水量演变规律分析

Analysis of Evolution of Water Quality and Quantity in Yichang River Basin

研究义昌江流域降水量、径流量和水质指标演变规律,可为流域水资源开发利用、水环境保护和水生态改善提供数据支撑。运用线性趋势回归检验法研究其变化趋势,采用有序聚类分析法对其进行突变分析;分析水质指标时空变化,并进行水质评价;基于Pearson相关分析和双累积曲线法,研究义昌江流域水质变化的原因。结果表明:降水量、径流量、溶解氧、高锰酸盐指数、氨氮、粪大肠菌群变化趋势不明显。一般情况下,下游大冲口断面水质比上游断面好;从季节变化来看,冬季水质大部分合格、水质较好;从年变化来看,水质变化波动;径流对溶解氧、氨氮的影响比降水和水温更大,水温对高锰酸盐指数、粪大肠菌群的影响比降水和径流更大;水质指标变化受自然因素和人类活动共同影响。

The evolution rules of precipitation,runoff and water quality indexes in Yichang River Basin can provide data support for water resources development and utilization,water environment protection and water ecology improvement.The linear trend regression test is used to study the change trend,and the ordered cluster analysis is used to analyze the mutation.The space-time changes of water quality index is analyzed and the water quality is evaluated.Based on Pearson correlation analysis and double cumulative curve method,the causes of water quality changes in Yichang River Basin were studied.The results showed that the trend of precipitation,runoff,dissolved oxygen,permanganate index,ammonia nitrogen and fecal coliform was not obvious.In general,the water quality of the downstream section is better than that of the upstream section.From the perspective of seasonal changes,the water quality in winter is mostly qualified and better.From the perspective of annual changes,water quality changes fluctuate;the effect of runoff on dissolved oxygen and ammonia nitrogen was greater than that of precipitation and water temperature.The effect of water temperature on permanganate index and fecal coliform was greater than that of precipitation and runoff.The change of water quality indicators is affected by natural factors and human activities.