中文摘要：

2010年春季对盘溪河水质进行了采样监测,分析了春季盘溪河水质的日变化规律,运用非参数检验、方差分析和灰色关联度方法评价了盘溪河1 d内的水质变化情况.结果表明,盘溪河的t、DO、COD、Pb、Cd、Zn和Cu在上、中、下游都没有显著性差异（P〉0.05）,pH、EC、TP、TSS、BOD5、NO3--N、TN和NH4＋-N表现出显著性差异;盘溪河各水质参数日变化情况差别较大,TN、TP和EC的日变化趋势在上游呈波浪式逐渐增加,中游波动较小,下游呈＂单峰单谷＂型,峰值出现在中午12：00.COD变化曲线呈＂单峰＂型,上游和中游峰值都出现在10：00,下游的峰值在12：00;盘溪河Pb、Cd、Zn和Cu的浓度较低,中游Pb、Cd、Zn和Cu浓度的峰值出现在12：00;运用灰色关联度方法评价了盘溪河水质级别：上游在18：00和20：00为劣Ⅴ类,其余各时间段河流水质为Ⅱ类;中游在12：00时水质为劣Ⅴ类,其余各时间段河流水质为Ⅱ类;下游各时间段水质均为劣Ⅴ类.

英文摘要：

Based on the investigation of water quality of Panxi River in spring,2010,we assessed the diurnal variation of water quality in spring and the characteristics of water quality changes within a day by using non-parametric test,analysis of variance and grey relationship analysis.The results showed that the differences were not significant for t,DO,COD,Pb,Cd,Zn and Cu（P0.05） in upstream,midstream and downstream,but significant difference existed among the pH,EC,TP,TSS,BOD5,NO-3-N,TN and NH＋4-N contents.The diurnal variation of different water quality parameters presented distinct patterns： TN,TP and EC increased wavelike with time in upstream,fluctuated less in middle and showed the ＂single-peak single-valley＂ pattern in downstream,with the peak at 12：00.The diurnal variation of COD showed that ＂single-peak＂ pattern and with the peak at 10：00 in upstream and midstream and peak at 12：00 in downstream.The concentrations of Pb,Cd,Zn and Cu were low and peak at 12：00 in midstream;The grey relationship analysis indicated that the water quality in upstream was inferior to the Ⅴ class of surface water at 18：00 and 20：00 and were in the Ⅱ class of surface water for the rest hours,and the water quality in midstream was inferior to the Ⅴ class of surface water at 12：00 and were in the Ⅱ class of surface water for the rest hours;and the water quality in downstream was inferior to the Ⅴ class of surface water all time during investigation.