Understanding Drought in Afghanistan: How ENSO Helps Us Predict Food Crises

This figure shows how winter and spring wheat crops performed in Afghanistan from 2016 to 2021, based on reports from the Crop Monitor for Early Warning. Each year is labeled as either a La Niña (in blue) or an El Niño (in red) year. The maps show where crops were rated as either "Favorable," "Poor," or "Failure" at the end of the growing season. These ratings help us see how weather patterns like La Niña and El Niño affected wheat harvests across the country.

Afghanistan is one of the most food-insecure countries in the world. Years of conflict, economic hardship, and climate change have made it extremely difficult for farmers to grow enough food. One of the biggest threats to agriculture in Afghanistan is drought, which can ruin crops and leave families without enough to eat.

A new study, co-authored by NASA Harvest and partner scientists, takes a closer look at how a climate pattern called the El Niño–Southern Oscillation (ENSO) affects drought and farming in Afghanistan. The research was partially supported by the NASA Harvest consortium, which focuses on using satellite data to improve food security around the world.

ENSO is a natural climate cycle that changes ocean temperatures in the Pacific Ocean. This can affect weather patterns all over the world. The two main phases of ENSO are El Niño and La Niña. These events can influence how much rain or snow a country receives. In Afghanistan, that matters a lot, because snow and rain feed rivers and farmland.

Using satellite data and weather models, the researchers studied how ENSO has affected Afghanistan since 1981. They found that La Niña events sharply increase the chances of drought, especially in the North, Northeast, and West of the country. These droughts affect both rainfed and irrigated farming, including Afghanistan’s main crop: wheat.

During La Niña years, snow levels are lower than normal, which means less water flows into rivers when the snow melts. This leads to less water for irrigation. In fact, the study showed that snow water levels and runoff decreased by up to 30% to 42% in key river basins during La Niña. That’s a big deal for farmers who rely on that water to grow their crops.

The study also found that wheat yields—how much wheat is harvested per area of land—tend to be lower during La Niña years. This is especially true for rainfed wheat, which doesn’t have access to irrigation. These findings match with past reports from food security experts, who have seen crop failures and worsening hunger during La Niña years in Afghanistan.

Weston Anderson, one of the authors and a researcher with NASA Harvest, said: “These results demonstrate how droughts during La Niña events cascade through the hydrological system: from reduced precipitation and snowpack to lower runoff, dryer soils, higher evaporative stress and ultimately to lower wheat yields.  By highlighting where and how La Niña events lead to lower wheat yields, these results give us a clear pathway to improve early warnings in Afghanistan”

This research is an example of how NASA Harvest and its partners are using Earth science to help communities at risk. By understanding the connection between ENSO and drought, we can give farmers and policymakers the information they need to act early and save lives.

In a country where so many people depend on farming to survive, being able to predict drought can make all the difference. NASA Harvest is proud to support this work, and will continue to use satellite data to fight hunger and support food security worldwide.