This fact-sheet by FAOWater titled “Water at a glance” traces the relationship between water, agriculture, food security and poverty. People who have better access to water tend to have lower levels of undernourishment. If water is a key ingredient to food security, lack of it can be a major cause of famine and undernourishment, especially in areas where people depend on local agriculture for food and income.
In addition, erratic rainfall and seasonal differences in water availability can cause temporary food shortages; floods and droughts can cause some of the most intensive food emergencies. The availability of water varies dramatically by region. But even in areas with limited or erratic water supplies, maximizing their use can increase agricultural productivity enormously. That is the key to improving food security and reducing poverty, especially in the rural areas that are home to three-quarters of the world’s hungry people.
The presentation from the FAO website - "Discover Water: 10 minute guided tour" discusses the relationship between water, agriculture, food security and poverty. The tour offers a synthesis as well as key facts and figures.