Severe floods across West Africa after heavy rains beginning in July 2007 have destroyed homes, crops and infrastructure and polluted water sources. The United Nations estimates that 800,000 people have been affected in 14 countries, around 210 people have died, and tens of thousands have been left homeless.

• Floods worst in 30 years
• Fears of waterborne diseases like cholera
• Disaster coincides with annual lean season

According to the U.N. Office for the Coordination of Humanitarian Affairs, the worst-hit countries are Ghana - where 333,000 people have been affected - Burkina Faso, Togo and Mali. Other countries that have been struck by floods are Mauritania, Niger, Ivory Coast, Gambia, Senegal, Benin, Nigeria, Sierra Leone, Liberia and Guinea.

West Africa is home to some of the world's least developed and poorest countries. Many households in the normally arid Sahel belt south of the Sahara desert already face difficulties finding food.

The onset of the crisis coincided with the annual lean season, when food reserves run low in the lead-up to the harvest in mid-September or October. Shortages have been made worse by the floods which damaged farms and crops, and washed away cattle.

The flooding was also expected to disrupt the start of the school year, with many school buildings damaged or being used to shelter families who've lost their homes.

International aid agencies have begun emergency food distributions, in some cases using helicopters and boats. A number have appealed for funds to support their disaster response work.

In early October, the United Nations and aid agencies launched an appeal for $10 million to assist 75,000 affected people for six months in Ghana - where the floods followed a drought that hit northern regions hard earlier in the year. The U.N. Central Emergency Fund allocated $3.7 million in emergency funding to Mali, Ghana and Togo.