Abstract
In Brazil, the northeastern region (NEB) is considered one of the most vulnerable areas of the country in terms of precipitation variability due to frequent drought episodes during the rainy season. Differently from the Northern NEB (NNEB), where dry season is consistently dry, the Eastern NEB (ENEB) exhibits a high interannual variability of precipitation during the dry season, including years exceeding 400 mm. This work aims at understanding key large-scale climate factors that modulate the high pluviometric variability of ENEB during the dry season. Multivariate statistical techniques were applied to identify the time-frequency relationship between precipitation variability and global climate phenomena. The results suggested that hydrological extreme events during the dry season became more frequent after the 1990s. Moreover, our findings also indicated a relationship, at multiannual time scales, between the state of El Niño Southern Oscillation (ENSO) and Atlantic Meridional Mode (AMM) and precipitation variability during the dry season. This additional knowledge may contribute to the formation of new perspectives of drought management, leading support to the development of a long-term drought forecasting framework, as well as to the improvement of the water resources management of the region.
Highlights
How large-scale climate variability impacts local hydrology is strategic information regarding the water resources management of a hydrological region, allowing a better understanding of the occurrence of extreme events such as droughts and floods [1,2]
Precipitation at the Northern Northeastern region of Brazil (NEB) (NNEB) is characterized by a rainy season from January to May marked by expressive interannual variability [8,16,18,19], and a dry season from June to December characterized by very low amounts of precipitation
To represent the overall variance of the OND precipitation, Ref. [29] have applied cluster analysis on the precipitation data after filtering them by means of Principal Component Analysis (PCA), preserving 75% of the original data variability. Their results pointed to two sub-regions of homogeneous precipitation variability (HG1 and HG2) which are presented in Figure 1b and are used in this work
Summary
How large-scale climate variability impacts local hydrology is strategic information regarding the water resources management of a hydrological region, allowing a better understanding of the occurrence of extreme events such as droughts and floods [1,2]. The Northeastern region of Brazil (NEB) is the most vulnerable socio-economic area of the country [6,7] It exhibits a very large interannual variability of precipitation [8,9,10] during the rainy season with a high intensity of extreme events such as the drought from 2012 to 2016 [11] and the 2010 flood episodes [12]. Eastern NEB (ENEB) has the highest annual average precipitation of the NEB, with a wet season from March to August, is susceptible to annual variations [20,21], but in a different way than the NNEB, while the ENEB dry season might receive substantial amount of precipitation in some years
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.
