Reference conditions of water bodies are defined as the natural or minimal anthropogenically disturbed state. We compared the methods for determining total phosphorus and total nitrogen concentrations in rivers in Finland, Norway and Sweden as well as the established reference conditions and evaluated the possibility for transfer and harmonisation of methods. We found that both methods and values differed, especially for lowland rivers with a high proportion of agriculture in the catchment. Since Denmark has not yet set reference conditions for rivers, two of the Nordic methods were tested for Danish conditions. We conclude that some of the established methods are promising but that further development is required. We moreover argue that harmonisation of reference conditions is needed to obtain common benchmarks for assessing the impacts of current and future land use changes on water quality.

水体的参考条件定义为自然或最小人为干扰状态。我们比较了芬兰、挪威和瑞典河流中总磷和总氮浓度的测定方法以及已建立的参考条件，并评估了方法转移和统一的可能性。我们发现，方法和数值都不同，特别是对于流域内农业比例较高的低地河流。由于丹麦尚未设定河流参考条件，因此针对丹麦条件对两种北欧方法进行了测试。我们的结论是，一些已建立的方法很有前途，但需要进一步发展。此外，我们认为需要统一参考条件，以获得评估当前和未来土地利用变化对水质影响的共同基准。