While mountains and hills fill the western two-thirds of China. and cultivation is possible only in more or less spacious valleys. the eastern third of the country. except near the south coast, is mostly level plain. divided into the two vast lower basins of the Yang-tse-kiang and lIo-ang-ho, plus those of some lesser sea-flowing rivers. This plain reaches inward for 500 miles on the Yang tse-kiang and GOO on the Ho-ang-ho, and is so low that these rivers. as far up as Hankow or Si ngan-fu, are only about 150 feet above the sea. Hence their current becomes very slow, a freshet overspreads broad areas, the silt brought down is rapidly and evenly deposited, and the rivers have in times past extended over their respective plains and formed vast deltas. The Ho-ang-ho has repeatedly shifted its main mouth from north to south of the Shantung Peninsula and back again. In addition to this alluvial deposition, vast quantities of wind-blown dust from the deserts and mountain-sides of Tibet and Mon golia have for ages been falling upon the ever growing coast plains, constituting what is known as the 'loess.' (See paragraph on Geology.) Sub ordinate drainage basins of less extent are those of the Pci-ho, in Pe-chili: the Hwai-ho, in Ho-nan, consumed in irrigation works; and the small coast streams cut off from the Yang tse-kiang basin by the coast range that runs from Hong Kong to Ning-po. The coast is broken
with many hays and gulfs, and a number of fair lv good harbors. On the north is the Gulf of Pe-chi-li, with its arm, I-ao-tung Gulf. South of the mountainous Shantung Peninsula is the Yellow Sea, and in the south coast is the Gulf of •Tongking,. Of islands, the largest is Hainan, off the southern coast.
The lakes of China are almost all near the mouth of the Yang-tse-kiamr, the largest hav ing a circumference of about 220 miles, and named Tung-ling-1m, so called because it was con sidered the cradle of the aboriginal kings. Po yang-hu, 90 miles long, has its outlet in the Yang-tse-kiang, and is famous for its beautiful scenery and its picturesque islands. In this lake there are, in addition to those islands formed by nature. artificial floating islands on which farmers build habitations and raise crops, cattle, and fowls. The lakes of Kiang-su are important as reservoirs for the Grand Canal.
The Grand Canal, running from Hang-ehow to Tien-tsin, but practically serviceable through its feeders from Nanking to Peking, was formerly the route of the great fleet of vessels bearing the tribute of rice to the capital. Artificial rivers and canals greatly aid navigation in China.