Abstract
The Amazon River Basin (ARB) plays an important role in the hydrological cycle at the regional and global scales. According to the Intergovernmental Panel on Climate Change (IPCC), the incidence and severity of droughts could increase in this basin due to human-induced climate change. Therefore, the assessment of the impacts of extreme droughts in the ARB is of vital importance to develop appropriate drought mitigation strategies. The purpose of this study is to provide a comprehensive characterization of dry spells and extreme drought events in terms of occurrence, persistence, spatial extent, severity, and impacts on streamflow and vegetation in the ARB during the period 1901–2018. The Standardized Precipitation-Evapotranspiration Index (SPEI) at multiple time scales (i.e., 3, 6, and 12 months) was used as a drought index. A weak basin-wide drying trend was observed, but there was no evidence of a trend in extreme drought events in terms of spatial coverage, intensity, and duration for the period 1901–2018. Nevertheless, a progressive transition to drier-than-normal conditions was evident since the 1970s, coinciding with different patterns of coupling between the El Niño/Southern Oscillation (ENSO) phenomenon and the Pacific Decadal Oscillation (PDO), Atlantic Multidecadal Oscillation (AMO), and Madden–Julian Oscillation (MJO) as well as an increasing incidence of higher-than-normal surface air temperatures over the basin. Furthermore, a high recurrence of short-term drought events with high level of exposure to long-term drought conditions on the sub-basins Ucayali, Japurá-Caquetá, Jari, Jutaí, Marañón, and Xingu was observed in recent years. These results could be useful to guide social, economic, and water resource policy decision-making processes in the Amazon basin countries.
Highlights
IntroductionThe Amazon River Basin (ARB) is the largest water basin in the world and a dynamic ecosystem that flows through Brazil, Peru, Bolivia, Colombia, Ecuador, Venezuela, Guyana, and Suriname [1]
Water 2021, 13, x FOR PEER REVIEW2016 (Figure 4), where more than 30% of the entire Amazon River Basin (ARB). These results suggest the presence of an underlying multi-decadal oscillation in the occurrence of extensive drought conditions, which may be attributed to the effects of the Pacific and currence of extensive drought conditions, which may be attributed to the effects of the Atlantic multi-decadal variability on rainfall in the ARB [78]
The newest gridded global Standardized Precipitation Evapotranspiration Index (SPEI) drought product based on the Climatic Research Unit gridded Time Series (CRU TS) dataset was used as a drought index at different scales (3, 6, and 12 months) during the period
Summary
The Amazon River Basin (ARB) is the largest water basin in the world and a dynamic ecosystem that flows through Brazil, Peru, Bolivia, Colombia, Ecuador, Venezuela, Guyana, and Suriname [1]. It is the largest rainforest in the world [2]. 2/3rd of the ARB includes the states of Acre, Amazonas, Santa Catarina, Rondônia, and Roraima and part of the states of Amapá, Mato Grosso, and Pará in Brazil [3].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
