摘要
Abstract
In this paper,the water quality and its change trend in the Zhaoqing and Yunfu sections of the main stream of the Xijiang River in the past ten years were studied,and 15 water quality indicators in 6 sections were selected for analysis.The results showed that the single-factor evaluation showed that the water quality category was good in 2013 and 2015,and the proportion of Class Ⅰ.-Ⅲ.water reached more than 80％.The rest of the years were mildly polluted.In the comprehensive evaluation,the comprehensive water quality of the five sections of Fengkai,Liudu Water Plant,Sanrong Water Plant,Gaoyao and Deqing was good,the comprehensive pollution index was higher than 85,and the water quality reached the qualified or basically qualified grade.The reason for the difference between the single-factor evaluation and the comprehensive pollution evaluation is that the water in the river section is mainly affected by the excessive fecal E.coli,TP and DO.In addition,in long-term observation,it was found that there were excessive levels of fecal E.coli,TP and DO in the reservoir section,and these concentration fluctuations had a certain degree of moderate variability.The excessive standard of fecal E.coli is related to flow rate,temperature and fecal discharge from aquaculture and urban life;TP is affected by aquaculture,planting,urban life and rainfall;Dissolved oxygen is mainly affected by temperature and aquatic organisms.关键词
河段水质/主要污染物/综合评价/变化趋势Key words
river section water quality/major pollutants/comprehensive assessment/variation trend分类
资源环境
