Number ten. Lake Baikal holds 20% of the world's freshwater. Lake Baikal in Siberia is the world's oldest and deepest lake. It holds about 20% of the Earth's entire unfrozen freshwater supply, making it more than all of the North American Great Lakes combined.第十位貝加爾湖擁有世界淡水總量的 20%。位於西伯利亞的貝加爾湖是世界上最古老、最深的湖泊。它擁有地球上全部不凍淡水供應量的 20%,比所有北美五大湖的總和還要多。