Possible Impact of Climatic Change and Anomalies to Intensity-Duration-Frequency Curves of Canadian Municipalities and Water Resources of Canadian River Basins

气候变化和异常对加拿大城市强度-持续时间-频率曲线和加拿大流域水资源的可能影响

• 批准号: 155440-2012
• 负责人: Gan, ThianYew
• 金额: $ 1.75万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=593495
• 关键词: Possible; Impact; Climatic; Change; Anomalies

In recent decades, hydrologic extremes have been occurring more frequently and in greater severity worldwide, including Canada. In the Intergovernmental Panel Climate Change (IPCC) report of 2007, simulations of global climate models unanimously demonstrate that anthropogenic forcing of increased greenhouse gases caused unprecedented temperature rise at global scale in recent decades. As the Earth warms, higher temperatures lead to higher rates of evaporation and precipitation, which will increase the frequency and severity of extreme storms. In designing municipal infrastructures, Intensity-Duration-Frequency (IDF) curves, assumed to be stationary, are used extensively. However, the effect of global warming could modify the intensity of future extreme rainfall events, and so infrastructure design based on existing IDF curves could be under-estimated. Further, IDF curves of most Canadian cities are outdated, for they were developed from single-site analysis of rainfall data and an Extreme Value Type I (EVI) probability distribution calibrated by method of moments (MOM), instead of the General Extreme Value (GEV). The Canadian climate can also be affected by climate anomalies such as El Nino Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO). It has been shown that El Nino lead to very low streamflow anomalies, while La Nina lead to high streamflow anomalies, in western Canada; and that winter precipitation in western Canada are significantly correlated with ENSO and PDO. To address these important issues, we will: (1) Replace obsolete IDF curves of some Canadian cities based on single-site analysis of EVI-MOM, with IDF curves based on multi-site analysis of GEV calibrated by the Probability Weighted Moment method; (2) Develop regional IDF curves using the ensemble empirical mode decomposition method; (3) Simulate potential impact of climate change to the IDF curves of selected Canadian cities by a mesoscale atmospheric model driven with projected climate scenarios of IPCC, first in a stand-alone, then a coupled modes to account for the land-atmospheric feedback; and (4) Assess the combined hydrologic impact of climate change and climate anomalies to some river basins of Canada.

近几十年来，包括加拿大在内的全球范围内，水文极端发生的频率更高，更严重。在2007年政府间委员会气候变化（IPCC）报告中，全球气候模型的模拟一致表明，人类气体的强迫增加了温室气体的增加导致近几十年来全球规模上的前所未有的温度升高。随着地球的变暖，较高的温度会导致蒸发和降水率较高，这将增加极端风暴的频率和严重性。在设计市政基础设施时，被假定为固定的强度 - 形式频率（IDF）曲线被广泛使用。但是，全球变暖的影响可能会改变未来的极端降雨事件的强度，因此基于现有的IDF曲线的基础设施设计可能会被低估。此外，大多数加拿大城市的IDF曲线已经过时，因为它们是根据降雨数据的单位点分析和通过矩（MOM）方法校准的极值I型（EVI）概率分布而开发的，而不是一般的极端值（ GEV）。加拿大气候也可能受到气候异常的影响，例如El Nino Southern振荡（ENSO）和太平洋际际振荡（PDO）。已经表明，埃尔尼诺（El Nino）导致了非常低的流量异常，而拉尼娜（La Nina）导致加拿大西部的高流量异常。加拿大西部的冬季降水与ENSO和PDO显着相关。为了解决这些重要问题，我们将：（1）基于EVI-MOM的单位点分析，取代了一些加拿大城市的过时的IDF曲线，而IDF曲线基于对概率加权力矩方法校准的GEV的多站点分析； （2）使用集合经验模式分解方法开发区域IDF曲线； （3）模拟气候变化对加拿大城市的IDF曲线的潜在影响，该大气模型由IPCC的预计气候场景驱动，首先是独立的，然后是一个耦合模式来说明土地 - 大气反馈； （4）评估气候变化和气候异常对加拿大某些河流盆地的合并水平影响。