Low plains occupy the rest of the Asian mainland, particularly the vast West Siberian and Turan plains of the interior. The remaining lowlands are distributed either in the maritime regions—such as the North Siberian and Yana-Indigirka lowlands and the North China Plain—or in the piedmont depressions of Mesopotamia, the Indo-Gangetic Plain, and mainland Southeast Asia. Those plains have monotonously level surfaces with wide valleys, through which the great Asian rivers and their tributaries flow. The topography of the plains in densely populated regions has been greatly modified through the construction of canals, dams, and levees. To the south of the ...(100 of 38030 words)