Climatic Controls on Mean and Extreme Streamflow Changes Across the Permafrost Region of Canada
Climatic Controls on Mean and Extreme Streamflow Changes Across the Permafrost Region of Canada
复制标题
加拿大永久冻土区平均和极端水流变化的气候控制
作者：
R. Shrestha;Jennifer C. Pesklevits;Daqing Yang;D. Peters;Y. Dibike
气候变化正在影响永久冻土区的水流状况，改变平均和极端的水流状况。本研究分析了加拿大多年冻土区84个水文站的年平均流量（Qmean）、最小流量（Qmin）、最大流量（Qmax）和Qmax时间的历史变化趋势。此外，我们将径流趋势与温度和降水趋势联系起来，并使用多元线性回归（MLR）框架来评估气候对径流成分的控制。结果显示，区域间的变化趋势存在空间差异，43%的台站的Qmin显著增加（10%水平），Qmean、Qmax和Qmax时间变化趋势显著的台站数量相对较少。在水文站上游70%的流域地区，冷暖季气温均显著升高，15%的流域地区降水增加。1976 ~ 2005年流域平均气候资料与降水量、气温的比较表明，库均值与季节降水量呈正相关，与季节气温呈负相关。流域平均流量、降水和温度趋势呈弱相关，其中Qmin与10 ~ 3月降水趋势呈正相关，Qmax时间与10 ~ 3月和4 ~ 9月气温趋势呈负相关。基于mlr的变量重要度分析显示，降水对Qmean和Qmax的控制优势，温度对Qmin的控制优势。总的来说，这项研究有助于加强对整个加拿大永久冻土区的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。
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 (Qmean), minimum flow (Qmin), maximum flow (Qmax) and Qmax 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) Qmin for 43% of stations as the most prominent trend, and a relatively smaller number of stations with significant Qmean, Qmax and Qmax 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 Qmean and seasonal precipitation, and a negative correlation between Qmean and seasonal temperature. The basin-averaged streamflow, precipitation and temperature trends showed weak correlations that included a positive correlation between Qmin and October to March precipitation trends, and negative correlations of Qmax timing with October to March and April to September temperature trends. The MLR-based variable importance analysis revealed the dominant controls of precipitation on Qmean and Qmax, and temperature on Qmin. 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.
影响因子：
30.7
作者：
Diffenbaugh, Noah S.;Scherer, Martin;Ashfaq, Moetasim
通讯作者：
Ashfaq, Moetasim
影响因子：
6.7
作者：
Box, Jason E.;Colgan, William T.;Olsen, Morten Skovgard
通讯作者：
Olsen, Morten Skovgard