Some Characteristics and Impacts of the Drought and Water Crisis in Southeastern Brazil during 2014 and 2015

Abstract

Since the austral summer of 2014 southeastern Brazil has been experiencing one of the most severe droughts in decades. This rainfall deficiency has generated water shortages and a water crisis that have affected population and local economies in the metropolitan region of Sao Paulo, the largest megacity in South America. By January 2015, main reservoirs had reached storage levels of only 5% of their 1.3 billion m3 capacity. The meteorological causes of the drought situation were linked to changes in the regional circulation, characterized by a mid-troposphere blocking high that lasted 45 days during the summer of 2014 over southeastern Brazil, something not seen in five decades. The water crisis was aggravated by a combination of lack of rainfall and higher temperatures, the summer of 2014 being the warmest and driest over the Cantareira reservoir system since 1951. Increasing population and water consumption increased vulnerability in the region, and while human-induced warming may not have generated the atmospheric conditions behind the 2014 and 2015 summer droughts in Southeast Brazil, it is more likely that the warm temperatures have affected the severity of the drought and exacerbated the impacts on the population.