天津市于桥水库水质变化特点及影响因素分析

采用非参数Mann-Kendall检验和Sen方法对于桥水库1986-2005年的水质参数(pH值、DO,COD,BOD5和NH3-N)的变化趋势和趋势量进行了统计和分析.结果表明:近20年来于桥水库水质能够满足其水功能规划Ⅲ类水质标准要求,pH值、D0,BOD5和NH3-N质量浓度均达到Ⅱ类水质标准,COD质量浓度也...

Change characteristics of water quality and its impact factor at the Yuqiao Reservoir in Tianjin

The change trends of water quality parameters,including pH,dissolved oxygen（DO）,chemical oxygen demand（COD）,biochemical oxygen demand（BOD5）,and ammonia nitrogen（NH3-N）,at the Yuqiao Reservoir in Tianjin,China from 1986 and 2005 were determined with the non-parametric Mann-Kendall test,and the magnitude of the trend was calculated with the non-parametric Sen＇s method.The results showed that water quality of the Yuqiao Reservoir could meet grade Ⅲ of the Environmental Quality Standards for Surface Water over the last 20 years.The pH value,and the concentrations of DO,BOD5,and NH3-N reached grade Ⅱ,but COD concentration reached grade Ⅲ.On the whole,the water quality tended to be stable,but DO concentration declined significantly,and COD concentration increased significantly.There was a significant negative correlation between DO and COD concentrations.The pH values increased slightly,and there was no significant change in BOD5 and NH3-N concentrations.With the acceleration of industrialization and urbanization,and the rapid growth of population in the surrounding area of the reservoir and the upper reaches,there was no significant change in water quality,which indicated that integrated management measures of water quality had achieved certain results.