广东榕江地都断面溶解氧变化规律及其影响因素研究

Study on the variation of dissolved oxygen and its influencing factors in Didu section of Rongjiang River,Guangdong

根据榕江干流下游地都断面近2年的降雨、水质监测数据,分析溶解氧(DO)在不同时间尺度下的变化规律,结合上游东湖断面水质监测数据,采用Pearson相关性分析、多元线性回归分析等方法分析不同环境因子对地都断面DO的影响。结果表明:受温度、光照及污染物等影响,地都断面DO具有白天高、夜间低,春秋冬高、夏季低,枯水期高、丰水期低的特点;地都断面DO与该断面pH、电导率均存在显著正相关关系(P<0.01),与水温均有较强的负相关关系,丰水期受沿程污染物输入影响更大。地都断面pH是影响其丰、枯水期DO变化的首要因子,可分别解释其DO整体变化的48.7%、45.1%,地都断面电导率、东湖断面总氮、东湖断面DO对地都断面DO也有一定影响。地都断面DO浓度总体随降雨强度增大而降低,暴雨时DO降幅最大,达41.95%。

Based on the rainfall and water quality monitoring data of the Didu section of the Rongjiang River downstream over the past two years,this study analyzed the variation patterns of dissolved oxygen(DO) at different temporal scales.By integrating the water quality monitoring data from the upstream Donghu section,methods such as Pearson correlation analysis and multiple linear regression analysis were employed to examine the impact of various environmental factors on the DO at the Didu section.The results indicated that due to the influences of temperature,light and pollutants,the DO at the Didu section exhibited characteristics of being higher during the day and lower at night;higher in spring,autumn,winter,and lower in summer;higher during the dry season,and lower during the wet season.There was a significant positive correlation between the DO at the Didu section and the pH,electrical conductivity(P<0.01) at the same section,and it had a strong negative correlation with water temperature.The impact of pollutant input along the river was greater during the wet season.The pH at the Didu section was the primary factor affecting the DO variation during both wet and dry seasons,explaining 48.7% and 45.1% of the overall DO changes,respectively.The electrical conductivity at the Didu section,total nitrogen at the Donghu section,and DO at the Donghu section also had certain influences on the DO at the Didu section.The DO concentration at the Didu section generally decreases with the increase of rainfall intensity,with the largest decrease observed during heavy rain,reached 41.95%.