School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China; School of Civil and Environmental Engineering, The University of New South Wales, Sydney, NSW 2052, Australia.
Sci Total Environ. 2014 Jan 15;468-469:877-91. doi: 10.1016/j.scitotenv.2013.09.002. Epub 2013 Sep 28.
To uncover climate-water quality relationships in large rivers on a global scale, the present study investigates the climate elasticity of river water quality (CEWQ) using long-term monthly records observed at 14 large rivers. Temperature and precipitation elasticities of 12 water quality parameters, highlighted by N- and P-nutrients, are assessed. General observations on elasticity values show the usefulness of this approach to describe the magnitude of stream water quality responses to climate change, which improves that of simple statistical correlation. Sensitivity type, intensity and variability rank of CEWQ are reported and specific characteristics and mechanism of elasticity of nutrient parameters are also revealed. Among them, the performance of ammonia, total phosphorus-air temperature models, and nitrite, orthophosphorus-precipitation models are the best. Spatial and temporal assessment shows that precipitation elasticity is more variable in space than temperature elasticity and that seasonal variation is more evident for precipitation elasticity than for temperature elasticity. Moreover, both anthropogenic activities and environmental factors are found to impact CEWQ for select variables. The major relationships that can be inferred include: (1) human population has a strong linear correlation with temperature elasticity of turbidity and total phosphorus; and (2) latitude has a strong linear correlation with precipitation elasticity of turbidity and N nutrients. As this work improves our understanding of the relation between climate factors and surface water quality, it is potentially helpful for investigating the effect of climate change on water quality in large rivers, such as on the long-term change of nutrient concentrations.
为了在全球范围内揭示大河的气候-水质关系，本研究利用 14 条大河的长期逐月观测数据，探讨了河流水质的气候弹性（CEWQ）。评估了 12 个水质参数（以 N 和 P 营养物为代表）的温度和降水弹性。对弹性值的一般观测表明，这种方法在描述河川水质对气候变化的响应程度方面非常有用，优于简单的统计相关。报告了 CEWQ 的敏感性类型、强度和可变性等级，并揭示了营养参数弹性的具体特征和机制。其中，氨、总磷-气温模型以及亚硝酸盐、正磷-降水模型的性能最佳。时空评估表明，降水弹性在空间上比温度弹性更具变异性，并且降水弹性的季节性变化比温度弹性更明显。此外，人为活动和环境因素都被发现对选定变量的 CEWQ 有影响。可以推断出的主要关系包括：（1）人口与浊度和总磷的温度弹性具有很强的线性相关性；（2）纬度与浊度和 N 营养物的降水弹性具有很强的线性相关性。由于这项工作提高了我们对气候因素与地表水水质之间关系的理解，因此对于研究气候变化对大河水质的影响（如营养物浓度的长期变化）可能会有所帮助。
