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DOI	10.5194/hess-22-3105-2018
	Historical drought patterns over Canada and their teleconnections with large-scale climate signals
	Asong Z.E.; Wheater H.S.; Bonsal B.; Razavi S.; Kurkute S.
发表日期	2018
ISSN	1027-5606
起始页码	3105
结束页码	3124
卷号	22 期号:6
英文摘要	Drought is a recurring extreme climate event and among the most costly natural disasters in the world. This is particularly true over Canada, where drought is both a frequent and damaging phenomenon with impacts on regional water resources, agriculture, industry, aquatic ecosystems, and health. However, nationwide drought assessments are currently lacking and impacted by limited ground-based observations. This study provides a comprehensive analysis of historical droughts over the whole of Canada, including the role of large-scale teleconnections. Drought events are characterized by the Standardized Precipitation Evapotranspiration Index (SPEI) over various temporal scales (1, 3, 6, and 12 consecutive months, 6 months from April to September, and 12 months from October to September) applied to different gridded monthly data sets for the period 1950-2013. The Mann-Kendall test, rotated empirical orthogonal function, continuous wavelet transform, and wavelet coherence analyses are used, respectively, to investigate the trend, spatio-temporal patterns, periodicity, and teleconnectivity of drought events. Results indicate that southern (northern) parts of the country experienced significant trends towards drier (wetter) conditions although substantial variability exists. Two spatially well-defined regions with different temporal evolution of droughts were identified - the Canadian Prairies and northern central Canada. The analyses also revealed the presence of a dominant periodicity of between 8 and 32 months in the Prairie region and between 8 and 40 months in the northern central region. These cycles of low-frequency variability are found to be associated principally with the Pacific-North American (PNA) and Multivariate El Niño/Southern Oscillation Index (MEI) relative to other considered large-scale climate indices. This study is the first of its kind to identify dominant periodicities in drought variability over the whole of Canada in terms of when the drought events occur, their duration, and how often they occur. © Author(s) 2018.
语种	英语
scopus关键词	Aquatic ecosystems; Disasters; Orthogonal functions; Water resources; Wavelet transforms; Comprehensive analysis; Continuous Wavelet Transform; Empirical Orthogonal Function; Ground-based observations; Large scale climate signals; Low frequency variability; Regional water resources; Spatiotemporal patterns; Drought; climate signal; data set; drought; El Nino-Southern Oscillation; environmental impact; extreme event; ground-based measurement; hazard assessment; historical record; multivariate analysis; precipitation (climatology); teleconnection; Canada; Pacific Coast [Canada]; Pacific Coast [North America]; Prairie Provinces
来源期刊	Hydrology and Earth System Sciences
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/160012
作者单位	Asong, Z.E., Global Institute for Water Security, School of Environment and Sustainability, University of Saskatchewan, 11 Innovation Blvd, Saskatoon, SK S7N 3H5, Canada; Wheater, H.S., Global Institute for Water Security, School of Environment and Sustainability, University of Saskatchewan, 11 Innovation Blvd, Saskatoon, SK S7N 3H5, Canada; Bonsal, B., Environment and Climate Change Canada, 11 Innovation Blvd, Saskatoon, SK S7N 3H5, Canada; Razavi, S., Global Institute for Water Security, School of Environment and Sustainability, University of Saskatchewan, 11 Innovation Blvd, Saskatoon, SK S7N 3H5, Canada; Kurkute, S., Global Institute for Water Security, School of Environment and Sustainability, University of Saskatchewan, 11 Innovation Blvd, Saskatoon, SK S7N 3H5, Canada
推荐引用方式 GB/T 7714	Asong Z.E.,Wheater H.S.,Bonsal B.,et al. Historical drought patterns over Canada and their teleconnections with large-scale climate signals[J],2018,22(6).
APA	Asong Z.E.,Wheater H.S.,Bonsal B.,Razavi S.,&Kurkute S..(2018).Historical drought patterns over Canada and their teleconnections with large-scale climate signals.Hydrology and Earth System Sciences,22(6).
MLA	Asong Z.E.,et al."Historical drought patterns over Canada and their teleconnections with large-scale climate signals".Hydrology and Earth System Sciences 22.6(2018).