Sources of uncertainty in hydrological climate impact assessment: a cross-scale study
Sources of uncertainty in hydrological climate impact assessment: a cross-scale study
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DOI：
10.1088/1748-9326/aa9938
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发表时间：
2018-01-01
影响因子：
6.7
通讯作者：
Krysnaova, V.
中科院分区：
文献类型：
--
作者：
Hattermann, F. F.;Vetter, T.;Krysnaova, V.
气候变化对水资源可用性和水文极端情况的影响是可持续发展目标方面的主要关切。对水文的影响通常是作为建模链的一部分进行调查的，在这一链中，根据不同的温室气体排放情景，将多个气候模型的气候预测用作多个影响模型的输入，这些情景导致不同的全球气温上升幅度。虽然目标一般是调查气候变化与水循环、水资源或水文极端情况的相关性，但情况往往是模型链其他组成部分的变化掩盖了气候情景变化的影响。在评估相对较低程度的全球变暖的影响时，这一点尤其重要，例如与《巴黎协定》的预期目标相关的影响。在我们的研究中，我们使用方差分析（方差分析）来分配和量化水文影响建模链中的主要不确定性来源。反过来，我们确定不同来源的不确定性的统计意义。我们通过使用一套五个气候模型和多达13个水文模型，在四种排放情景下，对地球仪的九个大尺度流域进行模拟。我们在分析中考虑的影响变量是每日河流流量。我们分析整体水资源的可用性和流量状况，包括季节性，高流量和低流量。尺度效应的研究分别在全球和区域水文模型产生的流量。最后，我们将我们的结果与其他最近发表的研究进行了比较，我们发现，与某些排放情景相关的全球气温上升的微小差异对河流流量有显著的影响，然而，与气候模型相关的不确定性是如此之大，以至于它掩盖了水文系统的敏感性。
Climate change impacts on water availability and hydrological extremes aremajor concerns as regards the Sustainable Development Goals. Impacts on hydrology are normally investigated as part of a modelling chain, in which climate projections from multiple climate models are used as inputs to multiple impact models, under different greenhouse gas emissions scenarios, which result in different amounts of global temperature rise. While the goal is generally to investigate the relevance of changes in climate for the water cycle, water resources or hydrological extremes, it is often the case that variations in other components of the model chain obscure the effect of climate scenario variation. This is particularly important when assessing the impacts of relatively lower magnitudes of global warming, such as those associated with the aspirational goals of the Paris Agreement.In our study, we use ANOVA (analyses of variance) to allocate and quantify the main sources of uncertainty in the hydrological impact modelling chain. In turn we determine the statistical significance of different sources of uncertainty. We achieve this by using a set of five climate models and up to 13 hydrological models, for nine large scale river basins across the globe, under four emissions scenarios. The impact variable we consider in our analysis is daily river discharge. We analyze overall water availability and flow regime, including seasonality, high flows and low flows. Scaling effects are investigated by separately looking at discharge generated by global and regional hydrological models respectively. Finally, we compare our results with other recently published studies.We find that small differences in global temperature rise associated with some emissions scenarios have mostly significant impacts on river discharge-however, climate model related uncertainty is so large that it obscures the sensitivity of the hydrological system.