Climatic change is affecting streamflow regimes of the permafrost region, altering mean and extreme streamflow conditions. In this study, we analyzed historical trends in annual mean flow (Q_mean), minimum flow (Q_min), maximum flow (Q_max) and Q_max timing across 84 hydrometric stations in the permafrost region of Canada. Furthermore, we related streamflow trends with temperature and precipitation trends, and used a multiple linear regression (MLR) framework to evaluate climatic controls on streamflow components. The results revealed spatially varied trends across the region, with significantly increasing (at 10% level) Q_min for 43% of stations as the most prominent trend, and a relatively smaller number of stations with significant Q_mean, Q_max and Q_max timing trends. Temperatures over both the cold and warm seasons showed significant warming for >70% of basin areas upstream of the hydrometric stations, while precipitation exhibited increases for >15% of the basins. Comparisons of the 1976 to 2005 basin-averaged climatological means of streamflow variables with precipitation and temperature revealed a positive correlation between Q_mean and seasonal precipitation, and a negative correlation between Q_mean and seasonal temperature. The basin-averaged streamflow, precipitation and temperature trends showed weak correlations that included a positive correlation between Q_min and October to March precipitation trends, and negative correlations of Q_max timing with October to March and April to September temperature trends. The MLR-based variable importance analysis revealed the dominant controls of precipitation on Q_mean and Q_max, and temperature on Q_min. Overall, this study contributes towards an enhanced understanding of ongoing changes in streamflow regimes and their climatic controls across the Canadian permafrost region, which could be generalized for the broader pan-Arctic regions.

中文翻译：

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气候变化对加拿大多年冻土区平均流量和极端流量变化的控制

气候变化正在影响多年冻土区的水流状况，从而改变了平均和极端的水流条件。在这项研究中，我们分析了加拿大多年冻土区84个水文站的年平均流量（Q _mean），最小流量（Q _min），最大流量（Q _max）和Q _max定时的历史趋势。此外，我们将流量趋势与温度和降水趋势相关联，并使用多元线性回归（MLR）框架来评估流量分量的气候控制。结果显示空间上变化的趋势在整个区域，与显著增加（在10％的水平）问_分钟其中43％的电台是最突出的趋势，相对较少的电台具有显着的Q _mean，Q _max和Q _max时序趋势。在冷水期和暖季的温度都表明，水文站上游流域> 70％的地区出现了明显的变暖，而流域> 15％的流域的降水却增加了。与降水量和温度径流变量的1976至2005年盆平均气候装置的比较显示Q之间存在正相关_均值和季节降水和Q之间的负相关，_平均和季节性温度。流域平均流量，降水和温度趋势显示出弱相关性，其中包括Q _min和10月至3月降水趋势之间的正相关，以及Q _max时序与10月至3月和4月至9月温度趋势的负相关。基于MLR的变量重要性分析显示，降水的主要控制因素是Q_均值和Q _max以及温度Q _min。总体而言，这项研究有助于加深对加拿大多年冻土地区水流状况及其气候控制的持续变化的理解，这可以推广到更广泛的泛北极地区。