Freshwater
Lake Baikal, located in southern Russia, is the deepest lake in the world, reaching a depth of 1,620 meters (5,315 feet). The lake contains 20 percent of the world’s unfrozen freshwater, making it the largest reservoir on Earth. It is also the world’s oldest lake, at 25 million years old.
The Yangtze is the longest river in Asia and the third longest in the world (behind the Amazon of South America and the Nile of Africa). Reaching 6,300 kilometers (3,915 miles) in length, the Yangtze moves east from the glaciers of the Tibetan Plateau to the river’s mouth on the East China Sea. The Yangtze is considered the lifeblood of China. It drains one-fifth of the country’s land area, is home to one-third of its population, and contributes greatly to China’s economy.
The Tigris and Euphrates Rivers begin in the highlands of eastern Turkey and flow through Syria and Iraq, joining in the city of Qurna, Iraq, before emptying into the Persian Gulf. The land between the two rivers, known as Mesopotamia, was the center of the earliest civilizations, including Sumer and the Akkadian Empire. Today, the Tigris-Euphrates river system is under threat from increased agricultural and industrial use. These pressures have caused desertification and increased salts in the soil, severely damaging local watershed habitats.