Is there an underestimation of long-term variability of streamflow across the continental United States?

doi:10.1016/j.jhydrol.2019.124365

	Is there an underestimation of long-term variability of streamflow across the continental United States?
	Sang, Yan-Fang 2; Sivakumar, Bellie 1; Zhang, Yichi 2
刊名	JOURNAL OF HYDROLOGY
	2020-02-01
卷号	581 页码:8
关键词	Streamflow Long-term variability Nonstationarity Trend Significance Discrete wavelet spectrum
ISSN号	0022-1694
DOI	10.1016/j.jhydrol.2019.124365
通讯作者	Sang, Yan-Fang(sangyf@igsnrr.ac.cn)
英文摘要	Analysis of the long-term variability of terrestrial streamflow is important for a wide range of studies in hydroclimatology and environment. However, the common practice of detecting only the monotonic trend cannot actually reflect the long-term variability and change in streamflow, thus resulting in an insufficient or biased understanding. This study focuses on the non-monotonic trends of streamflow and its spatial variability across the continental United States (US). Annual streamflow data observed during 1951-2002 at 530 stations across the continental US are studied. The discrete wavelet spectrum (DWS) is used to detect the non-monotonic trend of streamflow and evaluate its statistical significance. The results indicate significant non-monotonic trends in annual streamflow at 172 stations in the northeast Zone and the northern part of the southeast Zone (in the regions east of 100 degrees W). However, considering only the monotonic trends (being significant at only 38 stations) causes a biased understanding of the long-term variability of streamflow in the northeast zone. The results also reveal that the non-monotonic trend of streamflow in the continental US was mainly controlled by the climatic conditions and that the effects of landscape conditions were weak. The average aridity index (AI) of 0.86-1.35 and its DWS-based significance level > 0.1 can indicate the significant non-monotonic trend of streamflow at 95% confidence level. The regions that can meet the above two conditions account for 16% of the global terrestrial surfaces. By considering non-monotonic trends, the change ratio of streamflow is found to be double of that of AI, while similar change ratios are obtained from the monotonic trend results, as the reason of significant underestimation. Due to the partly equal roles of low-frequency oscillation and monotonic trend, identification of the non-monotonic trend should be more desirable for the detection and attribution of the long-term variability and change in streamflow.
资助项目	National Key Research and Development Program of China[2017YFA0603702] ; Second Tibetan Plateau Scientific Expedition and Research Program (STEP)[2019QZKK0903] ; National Natural Science Foundation of China[41971040] ; Youth Innovation Promotion Association CAS[2017074]
WOS关键词	CLIMATIC VARIABILITY ; TRENDS ; MULTISCALE ; PATTERNS ; US ; DECOMPOSITION ; DYNAMICS ; TESTS ; FLOW
WOS研究方向	Engineering ; Geology ; Water Resources
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000514758300021
资助机构	National Key Research and Development Program of China ; Second Tibetan Plateau Scientific Expedition and Research Program (STEP) ; National Natural Science Foundation of China ; Youth Innovation Promotion Association CAS
内容类型	期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/132643]
专题	中国科学院地理科学与资源研究所
通讯作者	Sang, Yan-Fang
作者单位	1.Indian Inst Technol, Dept Civil Engn, Mumbai 400076, Maharashtra, India 2.Chinese Acad Sci, Key Lab Water Cycle & Related Land Surface Proc, Inst Geog Sci & Nat Resources Res, Beijing 100101, Peoples R China
推荐引用方式 GB/T 7714	Sang, Yan-Fang,Sivakumar, Bellie,Zhang, Yichi. Is there an underestimation of long-term variability of streamflow across the continental United States?[J]. JOURNAL OF HYDROLOGY,2020,581:8.
APA	Sang, Yan-Fang,Sivakumar, Bellie,&Zhang, Yichi.(2020).Is there an underestimation of long-term variability of streamflow across the continental United States?.JOURNAL OF HYDROLOGY,581,8.
MLA	Sang, Yan-Fang,et al."Is there an underestimation of long-term variability of streamflow across the continental United States?".JOURNAL OF HYDROLOGY 581(2020):8.