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  • Writer's pictureDakila News

Drought in the Amazon: Understanding the Causes and Impact

In the months of September and October, the El Niño events and the rise in sea surface temperatures in the Atlantic Ocean have triggered an extensive and prolonged drought in the Amazon region, affecting the three pillars of sustainability.

The Amazon Basin is the largest in the world and accounts for 20% of Earth's freshwater, yet it experiences cyclical periods of drought and flooding. Typically, the rainy season in this region extends from November to March, with the dry season occurring from May to September, with transitional months in April and October.

Despite being in a transitional month, several factors intensified this year's dry season, including the effects of El Niño and the unusual increase in Atlantic Ocean temperatures. Out of the 62 municipalities in the state of Amazonas, only three are not under a state of emergency. Furthermore, 38 rivers in this basin are experiencing drought, with particular concern for the three major rivers: Madeira, Negro, and Solimões.

The Madeira River, which spans 1,500 kilometers, has been transformed into a landscape resembling a desert due to a significant drop in its water level. This drastic decrease in the river's level led to a two-week shutdown of the Santo Antônio hydroelectric plant located in Rondônia.

The Negro River is the seventh largest in the world in terms of water volume and recorded its lowest level on October 16th with a depth of 13.59 meters. While this is alarming, in 2010, the river experienced a similar low of 13.63 meters.

Before the current drought, the Solimões River also hit its lowest level in 2010, with a recorded depth of 3.92 meters. In this October, it was recorded at 3.61 meters according to data from the Brazilian Geological Service (SGB). The Solimões River originates in Peru and passes through 24 cities in the state of Amazonas, including Manaus, where it meets the Negro River to form the Amazon River.


This cascade of events is primarily due to the cyclical El Niño phenomenon and the unusual warming of the Atlantic Ocean. El Niño is responsible for abnormal warming of the surface waters of the Pacific Ocean, disrupting temperature balance and directly affecting rainfall patterns globally, including in the Amazon region. This leads to reduced humidity and rainfall scarcity.

While considered abnormal warming, El Niño occurs every two to seven years and alternates with La Niña, which cools the ocean. Regina Alvalá, acting director of CEMADEN (National Center for Monitoring and Alerts of Natural Disasters), points out that "in general, there is moisture transport by winds, especially in the southern region of South America. With more water vapor in the atmosphere, there is more rain in the southern region of Brazil and, consequently, less rain in the northern part of the country."

Likewise, the increased temperature in the Atlantic Ocean has also reduced the accumulation of rainfall in the region. Although many attribute this drought to human-induced climate change, researcher and meteorologist Giovanni Dolif asserts that such an association cannot be made without accounting for the cyclical and natural events in the region.

Apart from these cyclical and natural factors, several contributors amplify the drought and its impacts. Notably, deforestation, which raises temperatures and limits the forest's ability to regulate the climate and retain moisture. Reduced vegetation leads to less evapotranspiration, a crucial process in maintaining the hydrological balance.

Another key factor, especially in this region, is the construction of hydroelectric power plants. The Jirau and Santo Antônio dams, located along the Madeira River, have disrupted the natural hydrological cycle, diverting water flow.

The combination of these factors has led to an intense drought in the northern region, impacting social, economic, and environmental aspects, also known as the pillars of sustainability.


Direct environmental impacts include the death of aquatic life, including fish and dolphins, as well as the loss of vegetation and increased susceptibility to wildfires.

Thousands of dead fish have been seen floating on the water's surface, and approximately 140 dolphins of different species were found dead, according to the Mamirauá Institute. Miriam Marmontel, an expert in aquatic mammals, states, "It's something that has never been seen before, even in other extreme droughts, and there is no record of it in other locations or with other species." The causes of these dolphin deaths are still under investigation

Data indicates that at least 690 kilometers of vegetation are compromised, contributing to intentional wildfires. This was particularly felt in Manaus at the end of September when the city was engulfed in smoke, resulting in poor air quality according to the Selva (Environmental Surveillance Electronic System) metrics.

The Minister of the Environment and Climate Change addressed this situation in Manaus, stating, "There is a convergence of factors. The first of them is the severe drought caused by El Niño, worsened by climate change; a significant amount of dried organic matter; and intentional burning on private properties and within public areas as a criminal act."


This series of fires not only affected the environment but also the local population. Data indicates that Manaus experienced a concentration of 499 µg/m3 of particulate matter in the air, while the World Health Organization recommends a value of 5 µg/m3. Due to the poor air quality, many schools canceled outdoor activities, recommended the use of masks, and excused absences.

Additionally, numerous communities that rely on rivers and their tributaries have become isolated, lacking filtered water, food, and even fuel. As a result of this isolation, many children have been unable to attend school for over a month.

In the capital of Acre, around four thousand families are depending on water trucks for their potable water supply, similar to the situation in the Northeast region of the country.

Fisherman and farmer Raimundo Bezerra de Amaral, who lives along the Paranã de Tefé stream, says, "In 2010, it was worse in the sense that there was no water left, not even for bathing. Now, we have a trickle, for bathing and for the animals. But in 2010, it was 25 days like this. Now it's 40."


Moreover, there are economic problems, primarily affecting small producers. The Governor of Amazonas, Wilson Lima, has diagnosed that more than 112,000 fishermen will be affected by this drought.

As a result, many families have turned to agriculture, but the climate has not favored this practice. Farmer José Veloso Macedo reports, "We plant vegetables and greens. With the drought, nothing thrived. We water, but it doesn't help. The watermelons all died. What survived was cucumbers, beans, bananas, and a bit of green onion."

Another significant impact is on the transportation of goods and the suspension of the Santo Antônio hydroelectric plant, mentioned earlier. According to Luís Fernando Resano, the executive director of Abac (Brazilian Coastal Shipping Association), more than 60% of what is transported on the Amazon River may be affected during this period.


Despite the extreme difficulties and impacts of this period, the Madeira River has seen a 30cm increase in its water level in Humaitá. In Tabatinga, Peru, near the source of the Solimões River, water levels have also begun to rise. This increase has the potential to affect other regions, including the Negro River, which derives 70% of its water from the Solimões River. However, the rise in water levels for other rivers is expected to be slower, with researcher Jussara Cury of SGB predicting that this increase will only be felt in November.

Despite all the sustainability-related impacts described, this drought period has revealed some positive aspects in the field of archaeology. The low levels of the Negro River have unveiled new images at the archaeological site of Lajes, located between the confluence of the Negro and Solimões rivers. While the site has existed since 1968, the last time river levels allowed the visualization of such engravings was in 2010.

These new engravings are being analyzed, and their similarity to other records in Itacoatiara suggests they date back to the first millennium AD. Residents of the region have also reported that these stone blocks with engravings resemble the ruins of an ancient civilization. (Link:

References (in portuguese):


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