A lake is a large body of water on the land surface. Lakes account for approximately 1.8% of the total land area of the Earth. The largest numbers of lakes are in Northern Europe and North America. There are more than 2,800 natural lakes in China with areas greater than 1 km2. They are mainly distributed in the eastern plains, the Qinghai-Tibet and Yunnan-Guizhou Plateaus, and the Mengxin region. Lakes can be classified into different types based on their formation, including structural lakes, furiotile lakes, lagoons, crater lakes, barrier lakes, erosion lakes, glacial lakes and artificial lakes.