Note 608 — Chapter X · —Man's Relation To The Water

Such meager provisions against inundation suffice for the sparse population characterizing the lower stages of civilization, but they must be supplemented for the increasing density of higher stages by the embankment of the stream, to protect also the adjacent fields. Hence the process of confining rivers within dikes goes back into gray antiquity. Those of the Po and its tributaries were begun before the political history of the Lombardy plains commenced. Strabo mentions the canals and dikes of Venetia, whereby a part of the country was drained and rendered tillable.608 The main Po has been embanked for centuries as far up as Cremona, a distance of 600 miles, and the Adige to Verona.609 But the most gigantic dike system in the world is that of the Hoangho, by which a territory the size of England is won from the water for cultivation.610 The cost of protecting the far spread crops against the autumn floods has been a large annual expenditure and unceasing watchfulness; and this the Chinese have paid for two thousand years, but have not always purchased immunity. Year by year the Yellow River mounts higher and higher on its silted bed above the surrounding lowlands, increasing the strain on the banks and the area of destruction, when its fury is uncaged. The flood of 1887 covered an area estimated at 50,000 square miles, wiped out of existence a million people, and left a greater number a prey to famine.611 So the fertile Chengtu plain of the Min River, supporting four millions of people on its 2,500 square miles of area, owes its prosperity to the embanking and irrigating works of the engineer heroes, Li Ping and his son, who lived before the Christian era. On the temple in their honor in the city of Kuan Hsien is Li Ping's motto, incised in gold: "Dig the bed deep, keep the banks low." For twenty-one centuries these instructions have been carried out. The stone dikes are kept low to permit a judicious amount of flooding for fertilization, and every year five to six feet of silt are removed from the artificial channel of the Min. To this work the whole population of the Chengtu plain contributes.612 [See map page 8.]