A comparative study of drought characteristics using meteorological drought indices over the central main Ethiopian Rift

Autor: Wondimu T. Hailesilassie, Tenalem Ayenew, Sirak Tekleab
Jazyk: angličtina
Rok vydání: 2023
Předmět:
Zdroj: Hydrology Research, Vol 54, Iss 3, Pp 313-329 (2023)
Druh dokumentu: article
ISSN: 1998-9563
2224-7955
DOI: 10.2166/nh.2023.091
Popis: Droughts are defined by a prolonged absence of moisture. For making drought assessments, a drought index is a crucial tool. This study aims to compare drought characteristics across the Central Main Ethiopian Rift using three drought indices – the Standardized Precipitation Index (SPI), the Reconnaissance Drought Index (RDI), and the Standardized Precipitation Evapotranspiration Index (SPEI) – from 1980 to 2017 at six climate sites in spring, summer, and a 6-month period (March - August). With 1% and 5% significance levels, Modified Mann-Kendall and Sen's Slope Estimators were used to determine trend and magnitude, respectively. The temporal fluctuations of the three drought indices revealed that droughts are frequent, unpredictable, and random. Furthermore, they behaved similarly and had significant links. At most places, the drought indices found no significant trends. However, in the spring season, Butajira (by the three indices) and Wulbareg (by the SPI) showed significantly decreasing trends (increasing drought severity), with change rates ranging from −0.03 to −0.04/year. A comparison of drought characteristics revealed that droughts have become more severe and frequent in recent decades, with spring being more common than summer. This study, which employed a variety of drought indices, could assist water resource planners better understand drought events. HIGHLIGHTS Drought indices time series study offered important insight into how droughts varied over time from 1980 to 2017.; Drought parameters (frequency and severity) were examined over two distinct time periods (1980–1998 and 1999–2017).; Drought characteristics and trends revealed that the research area is more vulnerable to drought in the spring than in the summer at most sites.;
Databáze: Directory of Open Access Journals
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