气候变化领域集成服务门户(CCPortal): Investigating relationship between drought severity in Botswana and ENSO

CCPortal

DOI	10.1007/s11069-019-03810-1
	Investigating relationship between drought severity in Botswana and ENSO
	Byakatonda J.; Parida B.P.; Moalafhi D.B.; Kenabatho P.K.; Lesolle D.
发表日期	2020
ISSN	0921030X
起始页码	255
结束页码	278
卷号	100 期号:1
英文摘要	Influences of El Niño southern oscillation (ENSO) on weather systems have increased the frequency and amplitude of extreme events over the last century. This even continues to exacerbate the already warming earth, with 2014–2016 which coincided with the strongest El Niño years observed as the warmest period in recent past. This study presents an approach of characterizing droughts at various timescales and establishes teleconnections between ENSO and drought severity in Botswana. The study uses Standardized Precipitation Evaporation Index (SPEI) at timescales of 1, 3, 6, 12 and 24 month to characterize droughts and Pearson’s correlations to study the teleconnections between SPEIs and ENSO. Results from the study reveal that extreme droughts are a rare occurrence in Botswana though it is more prone to moderate droughts at 12 month SPEI with a probability of 19% in the north. The highest severe drought probability was 7% recorded in the east. Linear trends indicate increasing dryness of around 0.8% per decade. These results have demonstrated that warm sea surface temperatures combined with negative Southern Oscillation Index correspond to persistent negative SPEI values and thus are likely to result in dry conditions. Significant correlations were observed in the mid austral summer in December and January. Due to this relationship, the drought early warning systems could use ENSO as one of the instruments for predicting drought over the study area and hence in its management. © 2019, Springer Nature B.V.
关键词	Drought vulnerability Early warning El Niño Pearson’s correlation Standardized Precipitation Evaporation Index
英文关键词	air-sea interaction; correlation; drought; early warning system; El Nino-Southern Oscillation; evaporation; numerical model; precipitation (climatology); standardization; Botswana
语种	英语
来源期刊	Natural Hazards
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/205613
作者单位	Department of Biosystems Engineering, Gulu University, P.O Box 166, Gulu, Uganda; Department of Civil Engineering, University of Botswana, P/Bag 0061, Gaborone, Botswana; Department of Environmental Science, University of Botswana, P/Bag 00704, Gaborone, Botswana
推荐引用方式 GB/T 7714	Byakatonda J.,Parida B.P.,Moalafhi D.B.,et al. Investigating relationship between drought severity in Botswana and ENSO[J],2020,100(1).
APA	Byakatonda J.,Parida B.P.,Moalafhi D.B.,Kenabatho P.K.,&Lesolle D..(2020).Investigating relationship between drought severity in Botswana and ENSO.Natural Hazards,100(1).
MLA	Byakatonda J.,et al."Investigating relationship between drought severity in Botswana and ENSO".Natural Hazards 100.1(2020).