Reconstructing climate and hydrological variability in the Canadian cordillera

加拿大科迪勒拉和邻近大草原目前和未来气候变化最严重的影响将与需求增加时灌溉、水电、人类消费等用水的可用性有关。该项目审查了加拿大科迪勒拉选定区域水文循环组成部分的空间和时间变异性，方法是对过去的水文气候和积雪变异性进行树轮重建，检查仪器径流记录的变化，并记录冰川覆盖的最新变化。美国最近的研究表明，冬季积雪显著减少，水流时间较早，以及过去50年来水流的季节分布变化，这些都可能严重影响夏季的径流。正在进行的研究表明，冬季积雪、冰川物质平衡和夏季径流的这些强烈相关的区域变化模式是由PDO、ENSO和全球温度的变化驱动的。该项目的一个关键要素将是确定那些树木年轮系列对冬季降水或积雪敏感的树种，以便从水文角度重建夏季径流。它还将对过去几十年选定冰川最近(在某些情况下是每年)衰退的情况进行估计。这些研究将有助于由IAI资助的一个新的国际跨学科合作研究网络，该网络研究北美、墨西哥、玻利维亚、智利和阿根廷的气候变化。

The most critical impacts of ongoing and future climate changes in the Canadian Cordillera and adjacent prairies will be related to the availability of water for irrigation, hydro power, human consumption, etc. in times of increased demand. This project examines the spatial and temporal variability of components of the hydrological cycle in selected regions of the Canadian Cordillera by developing tree-ring reconstructions of past hydroclimate and snowpack variability, examination of changes in the instrumental streamflow record and documentation of recent changes in glacier cover. Recent studies from the US have shown marked reductions in winter snowpack, earlier streamflow timing and changes in the seasonal distribution of flows during the last 50 years that could critically affect summer flows. Ongoing studies show these strong coherent regional patterns of variation in winter snowpack, glacier mass balance and summer streamflow are driven by variations in the PDO, ENSO and global temperatures. A critical element of the project will be to identify those tree species with tree-ring series sensitive to winter precipitation or snowpack in order to develop hydrologically realistic reconstructions of summer streamflows. It will also develop estimates of recent (in some cases annual) recession of selected glaciers for the past few decades. These studies will contribute to a new international, interdisciplinary Collaborative Research Network funded by IAI that examines hydroclimatic variability in the cordillera of North America, Mexico, Bolivia, Chile and Argentina.