《Hydrological Processes》杂志刊登“ 在气候变化影响研究下对水文模型选择不确定性的评估”

作者：M. R. Najafi, H. Moradkhani, I. W. Jung

刊物：Hydrological Processes ，2011年8月30日，25卷18期，2814–2826页

关键词：不确定性；水文模型；气候变化；贝叶斯模型平均法；环流模型

摘要：大气-海洋环流模型和水文模型具有不确定性，这种不确定既可以依靠多模型的手段进行评估，在统计上也可以利用对八个环流模型模拟和两个排放情景得到的比例缩放结果进行评估。统计学上对大气作用的比例缩放用以驱动四个水文模型，其中有一个集中式水文模型和三个分布式水文模型，这四个水文模型具有不同的复杂性，它们分别是：萨克拉门托土壤水分计算（SAC-SMA）模型，概念水文模型(HYMOD)，水量平衡模型(TM)和降雨径流模拟系统（PRMS）。上述模型的校准是以三个目标函数为基础的，这些目标函数的作用是为研究创建更合理的模型。根据每个模型在观测期的表现和所有模型的总方差，水文模型模拟结合使用了贝叶斯模型平均法（BMA）。在以降雨为主的美国俄勒冈州图拉丁河流域进行了研究，结果表明，除了在旱季，水文模型的不确定性大大小于GCM的不确定性，这说明在对水文气候变化影响进行评估时，水文模型选择的组合至关重要。在分析整体结果时发现BMA在整合不同模型预计的径流估计时是有用的，同时也能够评估模型结构的不确定性。

Assessing the uncertainties of hydrologic model selection in climate change impact studies

Authors: M. R. Najafi, H. Moradkhani, I. W. Jung

Journal: Hydrological Processes, Volume 25, Issue 18, pages 2814–2826, 30 August 2011

Keywords: uncertainty; hydrologic modelling; climate change; Bayesian Model Averaging; GCM

Abstract：The uncertainties associated with atmosphere-ocean General Circulation Models (GCMs) and hydrologic models are assessed by means of multi-modelling and using the statistically downscaled outputs from eight GCM simulations and two emission scenarios. The statistically downscaled atmospheric forcing is used to drive four hydrologic models, three lumped and one distributed, of differing complexity: the Sacramento Soil Moisture Accounting (SAC-SMA) model, Conceptual HYdrologic MODel (HYMOD), Thornthwaite-Mather model (TM) and the Precipitation Runoff Modelling System (PRMS). The models are calibrated based on three objective functions to create more plausible models for the study. The hydrologic model simulations are then combined using the Bayesian Model Averaging (BMA) method according to the performance of each models in the observed period, and the total variance of the models. The study is conducted over the rainfall-dominated Tualatin River Basin (TRB) in Oregon, USA. This study shows that the hydrologic model uncertainty is considerably smaller than GCM uncertainty, except during the dry season, suggesting that the hydrologic model selection-combination is critical when assessing the hydrologic climate change impact. The implementation of the BMA in analysing the ensemble results is found to be useful in integrating the projected runoff estimations from different models, while enabling to assess the model structural uncertainty.

原文链接： http://onlinelibrary.wiley.com/doi/10.1002/hyp.8043/abstract