Rice farming in the Ganges Delta relies on several key physical factors:
1. The delta provides flat land that can be flooded to create rice fields, and receives over 2000mm of annual rainfall with at least 120mm each month of the 5-month growing season where temperatures are above 21 degrees Celsius.
2. Fertile alluvial soils are deposited annually by floodwaters of the Ganges River, providing rich, replenished soils for rice cultivation.
3. An impervious clay subsoil prevents water from draining away from the flooded rice fields during the growing season.