松花江干流肇源断面水体溶解氧动态特征分析

水体中溶解氧含量是判定水质的一个重要指标。基于松花江干流肇源断面不同时间尺度汇总数据的DO年内和年际变化趋势以及其与COD和NH_3-N关系分析表明,DO的年内变化趋势与松花江径流变化相关联,在平水期(04-06月和10-11月),DO值达到年内最高,介于7.64～7.70 mg/L;而在丰水期的(07-09月),DO值最低,在6.72～6.76 mg/L之间。年际间DO变化的特点是从2004-2010年,松花江干流的DO值呈增加趋势。不同时间尺度的数据整合结果有所差异,分析时间尺度越小,DO值变异性越强。回归分析表明,COD和NH_3-N对DO影响在枯水期显著(Sig≤0.001),DO与COD负相关,与NH_3-N正相关。

Dynamic Analysis of Dissolved Oxygen in Zhaoyuan Section of Songhuajiang Main Stream

Content of dissolved oxygen(DO) in water is an important index to assess water quality.DO changing trends at different temporal scales including weekly,monthly and yearly scale,and its effect on COD and NH_3-N in Zhaoyuan Section of Songhuajiang main stream were studied.Results showed that changing trend of DO was related to Songhuajiang runoff fluctuation within years,with the maximum DO 7.64～7.70 mg/L at non-flood period from April to June and October to November,and minimum 6.72～6.76 mg/L at flood period from July to September.Yearly DO changing was characterized as increasing by year from 2004 to 2010.Different analysis scale may cause different analysis results.Less analysis scale in time would result in larger variety of DO value.Regression analysis of DO with COD and NH_3-N indicated that their impacts were significant,with negative correlation between DO and COD,and positive between DO and NH_3-N.