A drought is a nasty thing to happen. A drought is an extended period of months or years when a region has a deficiency in its water supply. Generally, this occurs when a region receives consistently below average precipitation. It can have a substantial impact on the ecosystem and agriculture of the affected region. Although droughts can persist for several years, even a short, intense drought can cause significant damage and harm the local economy. Without rain, a rain forest does not last too long. For the second time this decade, drought grips the Amazon Basin. The lack of rain is drying up rivers like the Rio Negro, a main tributary of the mighty Amazon. The drought is primarily drying out the northwest region of Brazil, near the borders with Colombia and Peru. The same region suffered drought in 2005.

Periods of drought can have significant environmental, agricultural, economic and social consequences. The effect varies according to vulnerability. For example, subsistence farmers are more likely to migrate during drought because they do not have alternative food sources. Areas with populations that depend on subsistence farming as a major food source are more vulnerable to drought triggered famine.