Monsoons and Flood

Part of the Climate Change exhibition.

Wet Land

The annual, rain-bearing wind called the monsoon is the most important sign of the season for billions of people worldwide. When the monsoon arrives, vegetation springs to life; when the rains fail, drought and starvation may follow.

The Indian monsoon is perhaps the world's most dramatic. It starts when, in summer, heat builds up over the Indian subcontinent, Himalayas, and Tibetan Plateau. The warm air rises, drawing moist air in from the Arabian Sea. That air loses some of its moisture as it crosses the Indian subcontinent, bringing the rains of the summer monsoon. When it meets the towering Himalayas, the air cools and drops the rest of its moisture in the mountains as snow and sometimes as torrential rains.

Short Supply

In 2002, the monsoon arrived but was shorter than usual, ending in late June. A year later, scientists reported that more than 60 percent of India's vegetation was under either "severe" or "extreme" drought conditions. Among the affected regions was the state of Gujarat, where pressure on community wells (above) was intense.

Record Harvest

Plant growth on the Indian subcontinent depends almost entirely on the monsoon. Lush growth followied 2008's strong seasonal rains.