Meteorological and hydrological drought from 1987 to 2017 in Doce River Basin, Southeastern Brazil

Abstract

<jats:p>ABSTRACT Meteorological drought is a natural hazard characterized as below-average precipitation from expected or normal that can affect various economic sectors, and lead to period with inadequate streamflow for established uses of the water (hydrological drought). We aimed to apply the Standardized Precipitation Index (SPI) and Standardized Streamflow Index (SSI) to identify the occurrence and the intensity of droughts in Doce River Basin (DRB), Southeastern Brazil. For this purpose, 71 rain gauge stations and one streamflow station were selected with 30-year monthly historical series (1987 to 2017). The SPI and SSI were calculated for the hydrological year (October-September) and the seasons (Spring, Summer, Fall, and Winter). SPI mapping was performed by geostatistical procedures. Pearson's coefficient was calculated to analyze the influence of meteorological on hydrological drought. The main meteorological drought events, observed in the hydrological years of 1994/95, 2000/01, and a recent and consecutive period of four hydrological years (2013-2017), were mainly influenced by events in spring and summer and, to a lesser extent, in fall. It was observed the influence of the meteorological drought on the hydrological drought on an annual and seasonal scale, except winter, where low precipitation does not influence in the streamflow.</jats:p>

Hydrological Response to Drought Occurrences in a Brazilian Savanna Basin

“…During the period 2013/14 to 2017/18, similar events were found in other Brazilian regions such as the Doce river basin [14], Tocantins river basin [12], Northeastern Brazil [36], Amazon [36], Paraná river basin [37], the metropolitan region of São Paulo [38], and Ceará State [9], affecting the hydropower generation and urban supply. Besides, droughts can affect the ecological functions of the Brazilian savanna [34], as well as reduce the native fish species and increase exotic species [39].…”

“…According to Van Loon [7], rainfall deficit in the rainy season can influence following dry season conditions. In cases of longer meteorological drought, there may be a reduction in groundwater recharge, affecting the streamflow even after the meteorological conditions return to normal, as also reported by Jesus et al [14] in the Doce river basin and by Junqueira et al [12] in the Tocantins river basin. As an example, in the hydrological year 2017/18, the SPI was classified as near normal, however, the SSI was classified as moderately dry.…”

Adjustment of the Standardized Precipitation Index (SPI) for the Evaluation of Drought in the Arroyo Pechelín Basin, Colombia, under Zero Monthly Precipitation Conditions

“…The countries located in the equatorial belt generally present vulnerability to drought events due to their climatic characteristics of high temperatures [22][23][24][25][26][27] and had SPI in other ecosystems with warm environments, such as the Colombian Caribbean and the Pechelín stream basin, showing periods with low rainfall. Colombia has various meteorological characteristics depending on its geographical location and its orography, presenting warm climates in the regions of lower elevation for sea level.…”

Hydrological Retrospective and Historical Drought Analysis in a Brazilian Savanna Basin

“…5b), although there were some non-drought months within these events. Other Brazilian regions also experienced drought events in some of these years, such as the state of Ceará in 1958 and 2012/18 [68]; Northeastern Brazil in 1958Brazil in , 1970Brazil in , 1976Brazil in , 2001/02, and 2012/16 [69]; São Paulo city in 1962/63 and the metropolitan region of Belo Horizonte in 1970/71 [70], both in Southeastern Brazil; in the Doce River basin in 2000/01 and 2013/17 [71], Southeastern Brazil; and the Tocantins River basin from 2015 to 2017 [28], located in the Brazilian savanna; this confirms the adopted procedure's ability to represent the most relevant droughts.…”