尼亚加拉河1951—2016年水文气象要素演变特征及其响应性

The Evolution Characteristics and Responsiveness of Hydrometeorological Elements of the Niagara River from 1951 to 2016

尼亚加拉河是世界第一大瀑布的水源地,其水量的变化对于美国和加拿大的水力资源利用至关重要。分别采用Mann-Kendall趋势检验法、有序聚类法、小波功率谱法研究尼亚加拉河流域1951—2016年间的气温、降水、径流的时空演变特征,同时以径流深突变点分阶段分析了流域降水-径流关系。结果表明:1951—2016年间,尼亚加拉河流域的气温自1997年后显著升高;降水量自1964年之后呈现不显著增加趋势,且降水量空间分布不均匀,表现出西高东低的特点;流域径流深具有明显的阶段性变化特征,根据突变点将径流深序列划分为1951—1967年、1968—1997年、1998—2016年3个阶段,第Ⅱ阶段的流域径流深随着降水量的增加而明显减少,表明在此阶段其他非降水因素对径流深的变化有重要影响。

The Niagara River is the source of the largest waterfall in the world,and changes in its water volume are crucial to the utilization of water resources in the United States and Canada.The Mann-Kendall trend test method,ordered clustering method,and wavelet power spectrum method were applied to study the temporal and spatial evolution characteristics of temperature,precipitation,and runoff in the Niagara River Basin from 1951 to 2016.At the same time,the relationship between precipitation and runoff in the basin is analyzed by stages with the deep abrupt change point of runoff.The results are as follows.From 1951 to 2016,the temperature in the Niagara River Basin increased significantly since 1997.Precipitation has shown an insignificant increase trend after 1964,and the spatial distribution of precipitation is uneven,showing the characteristics of high in the west and low in the east.The runoff depth of the basin has obvious characteristics of stage changes.According to the mutation points,the runoff depth sequence is divided into three periods,namely 1951 to 1967,1968 to1997,and 1998 to 2016.In the second period of 1968 to1997,the runoff depth decreased significantly with the increase of precipitation,indicating that other non-precipitation factors in this period have an important influence on the change of runoff depth.