Assani Ali A
Department of Environmental Sciences and the Research Centre for Watershed-Aquatic Ecosystem Interactions (RIVE, UQTR), University of Quebec at Trois-Rivières, 3351 Boulevard des Forges, Trois-Rivières, QC G9A 5H7 Canada.
Appl Water Sci. 2024;14(5):109. doi: 10.1007/s13201-024-02180-9. Epub 2024 Apr 25.
The objective of this study is to compare the spatiotemporal variability of seasonal daily mean flows measured in 17 watersheds, grouped into three homogeneous hydroclimatic regions, during the period 1930-2023 in southern Quebec. With regard to spatial variability, unlike extreme daily flows, seasonal daily mean flows are very poorly correlated with physiographic factors and land use and land cover. In fall, they are not correlated with any physiographic or climatic factor. In winter, they are positively correlated with the rainfall and winter daily mean maximum temperatures. In spring, they are strongly correlated positively with the snowfall but negatively with the spring daily mean maximum temperatures. However, in summer, they are better correlated with forest area and, to a lesser extent, with the rainfall. As for their temporal variability, the application of six different statistical tests revealed a general increase in daily mean flows in winter due to early snowmelt and increased rainfall in fall. In summer, flows decreased significantly in the snowiest hydroclimatic region on the south shore due to the decrease in the snowfall. In spring, no significant change in flows was globally observed in the three hydroclimatic regions despite the decrease in the snowfall due to the increase in the rainfall. In fall, flows increased significantly south of 47°N on both shores due to the increase in the rainfall. This study demonstrates that, unlike extreme flows, the temporal variability of seasonal daily average flows is exclusively influenced by climatic variables in southern Quebec. Due to this influence, seasonal daily mean flows thus appear to be the best indicator for monitoring the impacts of changes in precipitation regimes and seasonal temperatures on river flows in southern Quebec.
本研究的目的是比较1930年至2023年期间在魁北克南部17个流域（分为三个同质水文气候区域）测量的季节性日平均流量的时空变异性。关于空间变异性，与极端日流量不同，季节性日平均流量与地貌因素以及土地利用和土地覆盖的相关性非常低。在秋季，它们与任何地貌或气候因素均无关联。在冬季，它们与降雨量和冬季日平均最高温度呈正相关。在春季，它们与降雪量呈强正相关，但与春季日平均最高温度呈负相关。然而，在夏季，它们与森林面积的相关性更好，与降雨量的相关性较小。至于它们的时间变异性，六种不同统计检验的应用表明，由于融雪提前和秋季降雨量增加，冬季的日平均流量普遍增加。在夏季，由于降雪量减少，南岸降雪量最大的水文气候区域的流量显著下降。在春季，尽管由于降雨量增加降雪量减少，但在这三个水文气候区域总体上未观察到流量有显著变化。在秋季，由于降雨量增加，两岸北纬47°以南的流量显著增加。这项研究表明，与极端流量不同，魁北克南部季节性日平均流量的时间变异性仅受气候变量影响。由于这种影响，季节性日平均流量因此似乎是监测降水模式和季节性温度变化对魁北克南部河流流量影响的最佳指标。
