Peru hit by worst floods in two decades

By David Jacobson, Temblor

Check your flood risk

A woman is helped across a flooded street in Huachipa. (Photo from: REUTERS/Guadalupe Pardo)


In what has been the worst flooding in two decades, 72 people have been killed by flooding in Peru, prompting state of emergencies to be declared in over 800 towns and cities across the country. Localized El Nino conditions, which have resulted in 10 times the normal amount of rain over the course of the rainy season, have caused flash floods to devastate parts of the capital city of Lima.

Widespread flooding in Peru has forced people to be rescued across the country. In this picture, a zipline is used to carry a woman across a flooded street. (Photo from: REUTERS/Guadalupe Pardo)


El Nino refers to the warming of the ocean surface in the central and eastern tropical Pacific Ocean. This increase in temperature leads to more evaporation, and can bring about heavy rain. However, in Peru, the warming is so significant that climatologists are referring to this phenomenon as a “coastal El Nino,” and warn that another, more traditional El Nino may be forming behind the current one. The rainfall from this event has led to water pouring out of the mountains and overwhelming towns. Additionally, for an arid city like Lima, which will often only see two inches for the entire rainy season, the effects have been significant.

This map shows ocean surface temperatures all over the world. The black box marks the significant increase in ocean temperatures that has resulted in heavy rainfall across Peru. (Data from NOAA/ESRL/PSD)


Because of the flooding, over 100,000 people have been left homeless, and the government has deployed the armed forces to help maintain law and order. Additionally, there are shortages of both food and water, leading to price increases, compounding the problem. Furthermore, though the rain has stopped for now, because the unstable weather will continue, Peru is unlikely to get relief for long.

People wait to be rescued after flash floods swept through Lima. (Photo from: Martin Mejia / AP)


Based on data from the World Resources Institute, the probability of flooding around Lima is significant in any given year. In the map shown below, it can be seen that the probability of flooding exceeds 20%. This flood probability appears isolated to the rivers which run through Lima. However, this year’s flooding is more significant and brings back memories to 1998, when flooding hit the country and 374 people died.

This map shows flood probabilities in and around Lima, Peru. Based on this data from the World Resources Institute, flooding on a yearly basis in Lima is high, though the floods this year are extreme. (Data from World Resources Institute)


Flash floods have caused extreme damage throughout Peru. These floods have been caused by El Nino conditions that have resulted in 10 times the normal amount of rainfall. (Photo from: Cris Bouroncle / AFP / Getty)


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