Impact of Climate Change on Water Resources and Hydrological Extremes

随着全球对淡水需求的增加，土地利用(LU)和气候变化(CC)使未来淡水的可获得性变得不确定。CC预计将影响当地的水供应、河流流量和季节性供水，从而使对水的适应措施在广泛的社会和环境方面不可或缺。*在这方面，申请人有助于理解CC对全球范围内水文气象变量的影响。他的贡献包括对全球降水预测的分析，这些预测表明今天的极端事件将加剧，即平均而言，降水可能不那么频繁，但更强烈，一些地区的干旱可能变得更加频繁和严重。地中海分水岭尺度的水文模拟显示，严重洪灾和长期干旱的风险可能增加，同时可用水在2100年之前逐渐减少，因此，需要改进和更新现有的CC适应做法和政策。在这项研究的推动下，申请者采取了加强CC研究的举措，导致对加拿大水文和水资源研究的区域气候模式(RCM)REMO强迫集得出的数据进行了评估，迄今取得了令人满意的结果。申请人还提出了一种改进的GCM逐日降水偏差校正方法，该方法从根本上减少了21世纪全球降水集合预测的校正引起的不确定性。使用最先进的RCM数据集，加拿大和欧洲分水岭的申请人最近进行了连接气候模式输出和流域尺度极端事件建模的综合研究，表明CC对基本水文气象特征的定量影响可能是巨大的。*申请人的研究建议的范围是促进对CC对水资源和极端事件的影响的基本了解，主要目标是：(A)通过水文学应用改善对全球气候变化及其对洪水和干旱的影响的了解，(B)开发和推广CC分析方法，(C)制作适用于水资源应用和极端事件研究及其固有风险的新的高分辨率气候数据集；(D)向研究人员提供培训并传播信息、方法和成果。将开展的方法将遵循四项主要活动：(1)在加拿大基础设施中采用非静力RCM，(2)改进偏差调整方法，将相关的水文变量缩小到流域尺度，(3)十年尺度预测方案的评估，以及(4)加拿大，特别是大湖区水资源和水文极端应用的设想。这项建议的新颖性在于对高优先领域的研究(使用非静力模式的北美高分辨率气候数据集、创新方法的开发和应用、对十年尺度预测方案的评估以产生政策发展应用的时间演变预测)。*拟议的研究预计将在科学和政策层面上产生重大影响。更好地了解全球气候与当地可用水和极端情况之间的跨尺度相互作用，将促进针对CC影响的缓解和适应措施。新的方法和数据集将进一步提升气候和水文学的科学水平，推动加拿大CC研究在学术、公共、工业和政府部门的发展。

As demand for freshwater on a global scale rises, land use (LU) and climate change (CC) render its availability into the future uncertain. CC is expected to affect local water availability, river discharge, and the seasonal availability of water supply, thus making adaptation measures for water indispensable for a wide range of social and environmental aspects.*In this context, the applicant has contributed to understanding the effects of CC on the hydrometeorological variables at global scale. His contributions includes analysis of global precipitation projections that indicates that today's extreme events will intensify, i.e., precipitation on average is likely to be less frequent but more intense and droughts are likely to become more frequent and severe in some regions. Hydrological modeling at watershed scale in the Mediterranean reveals the potential of an increased risk of severe flooding and prolonged droughts alongside a gradual decrease in water availability till 2100, thus suggesting that existing practices and policies for CC adaptation need to be improved and updated. Spurring from this research, the applicant has taken initiatives to enhance CC research that have led to the assessment of data derived from the Regional Climate Model (RCM) REMO forcing set for hydrological and water resources studies in Canada that have so far yielded satisfactory results. The applicant has also proposed an improved bias correction method for daily GCM precipitation that radically reduces the correction induced uncertainty of a global precipitation ensemble projection for the 21st century. Using state-of-the-art RCM datasets, integrated studies bridging climate model output and basin scale modeling for extreme events have recently been conducted by the applicant for Canadian and European watersheds, showing that the quantitative impact of CC in basic hydrometeorologic characteristics can be substantial.*The scope of the applicant's research proposal is the advancement of fundamental understanding of CC impact on water resources and extremes with the key objectives of: (a) improving understanding of global climate change and its effects on floods and droughts through hydrological applications, (b) developing and extending CC analysis methodologies, (c) producing new high resolution climatic datasets suitable for water resources applications and extreme event research as well as their inherent risks, (d) providing training to researchers and disseminate information, methodologies and results. The methodology to be carried out will follow four main activities: (1) Adoption of non-hydrostatic RCMs in Canadian infrastructure, (2) Improved Bias Adjustment Method to downscale relevant hydrological variables to basin scale, (3) Evaluation of the decadal-scale prediction scheme and (4) Scenarios for water resources and hydrological extremes applications in Canada and in particular the Great Lakes region. The novelty of this proposal resides with the research in high priority areas (high resolution climate datasets for N. America using non-hydrostatic models, development and application of innovative methodologies, evaluation of the decadal-scale prediction scheme to produce time-evolving predictions of policy development applications).*The proposed research is expected to have significant impact on both scientific and policy level. Improved understanding of the cross scale interactions of global climate and local water availability and extremes will promote both mitigation and adaptation measures against the impacts of CC. New methodologies and datasets will elevate the science of climate and hydrology further, driving the development of Canadian CC Research within the academic, public, industrial and government sectors.