Grande Seca

The Grande Seca (English: Great Drought), or the Brazilian drought of 1877–1878, was the largest and most devastating drought in Brazilian history. It caused the deaths of between 400,000 and 500,000 people. Of the 800,000 people who lived in the affected Northeastern region, around 120,000 migrated to the Amazon while 68,000 migrated to other parts of Brazil. The Grande Seca was exacerbated by poorly managed agriculture. Overgrazing, sharecropping, and lack of sustainable agricultural practice compounded the effects of the drought. The majority of the sertão population (sertanejos) were poor sharecroppers, who depended on the winter rains to provide water for crops and cattle. Without adequate preparation the peasants of the sertão were unprepared for extended drought and quickly began to starve. Reactions to the disaster were almost nonexistent. Outside Brazil, news outlets briefly covered the drought. In the most-affected state of Ceará, many pleas for help were written to the Brazilian government, but these were mostly ignored because of political and social biases. When aid eventually arrived, it was poorly distributed. The eventual government response was a bureau to address future droughts in 1909 and building a reservoir.

Causes and contributing factors

Environmental factors

The Brazilian Northeast is an area where political and social development has been hindered by the harsh environment of the arid sertão. Characterized by the presence of nine major rivers, among which are the São Francisco and the Parnaíba, the sertão has an average annual temperature of between 20 °C and 28 °C and a maximum of 40 °C. The pluviosity of the area is a source of concern for farmers and local governments alike. Although the annual average precipitation is slightly lower than 1,000 mm, the rainy period, which usually lasts just two months a year, is unstable. Sometimes precipitation halts for one year or more, often causing regional droughts. Sustained occurrences of below average water availability can happen in all areas of the country as a consequence of abnormally low precipitation rates and high evaporation rates; but it is in the Northeast where they happen with greater frequency. The zona da mata, which runs along the Northeastern coast and in which major cities are located. In this sub-biome, rains are frequent and vegetation is plentiful. This area does not usually suffer from droughts, but the magnitude of the Great Drought was so great that even the coastal region was impacted. Since the rivers that flow to the coast almost always have their origin in the sertão, a drought in the semiarid and arid sub-regions can extend to the entire Northeastern area. Prior to Portuguese settlement in the 16th century, there were no pressing problems because the predominant caatinga ecosystem was adapted to the cyclical climate. Indigenous groups who inhabited the land were affected by extreme droughts, which forced them to move to the humid coastal region, but these rarely occurred. The Northeast is heavily influenced by the El Niño phenomenon and by the surface temperatures of the Atlantic Ocean. El Niño years are characterized by below-average rainfall in the semiarid zone, which typically averages at 800 mm annually but is concentrated in a brief time period sometimes shorter than two months. During extreme droughts, precipitation can decrease by more than 50%. As a direct consequence of variation in climatic patterns around the world in 1877 parts of Ceará witnessed four days of rainfall from March 18 to March 21. These rains allowed seeds to germinate, but it wasn't enough to sustain agriculture and cattle herds. Much of the vegetation quickly perished. The situation created by increasing human migration to the Northeastern interior made the land more vulnerable to drought. The absence of water impacts agriculture first, but it also has economic, social, and environmental ramifications. Drought is now an integral part of the Northeastern environment and various episodes throughout history have caused serious damage to its states, though they are often forgotten once they pass. Agriculture and pasture outputs go back to normal, giving people a brief sense of security before the next drought arrives. This recurrence of events and behavioral stagnation was named the "hydroillogical cycle" by Professor Donald Wilhite of the University of Nebraska–Lincoln.

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