ABSTRACT We assessed the reproducibility of river state-of-environment (SoE) water quality measurements in the Wellington Region, New Zealand (NZ). Field staff from GWRC and NIWA conducted 29 side-by-side water sampling and in-situ measurements at six river sites of diverse water quality for 12 variables measured routinely in river SoE monitoring across NZ. Field measurements of water temperature, dissolved oxygen, electrical conductivity and visual clarity agreed closely with strong numerical similarity (within 10%). Numerical similarity ranged widely for laboratory measurements, from strong for nitrate-nitrite-nitrogen to weak for turbidity, dissolved reactive phosphorus, and ammoniacal-nitrogen. Numerical agreement was very weak for laboratory pH (which is problematic) and E. coli–which is ‘tolerable’ for many applications given good correlation (R = 0.94) over a 2000-fold concentration range. The findings of our inter-agency comparison have contributed to quality assurance recommendations in the NZ National Environmental Monitoring Standard (NEMS) for water quality.

中文翻译：

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河流水质测量的再现性：质量保证的机构间比较

摘要 我们评估了新西兰 (NZ) 惠灵顿地区河流环境状况 (SoE) 水质测量的可重复性。来自 GWRC 和 NIWA 的现场工作人员在 6 个水质不同的河流站点进行了 29 次并排水采样和原位测量，测量了新西兰河流 SoE 监测中常规测量的 12 个变量。现场测量的水温、溶解氧、电导率和视觉清晰度与很强的数值相似性（10% 以内）非常吻合。实验室测量的数值相似性范围很广，从硝酸盐-亚硝酸盐-氮的强到浊度、溶解的活性磷和氨氮的弱。实验室 pH 值（这是有问题的）和大肠杆菌的数值一致性非常弱。大肠杆菌——在 2000 倍的浓度范围内具有良好的相关性 (R = 0.94)，这对于许多应用来说是“可容忍的”。我们机构间比较的结果为新西兰国家环境监测标准 (NEMS) 中的水质质量保证建议做出了贡献。