Extent of canalization and
surface fitting of fields
On the evening of March 15th we left Canton for Hongkong and the following day embarked again on the Tosa Maru for Shanghai. Although our steamer stood so far to sea that we were generally out of sight of land except for some off-shore islands, the water was turbid most of the way after we had crossed the Tropic of Cancer off the mouth of the Han river at Swatow. Over a sea bottom measuring more than six hundred miles northward along the coast, and perhaps fifty miles to sea, unnumbered acre-feet of the richest soil of China are being borne beyond the reach of her four hundred millions of people and the children to follow them. Surely it must be one of the great tasks of future statesmanship, education and engineering skill to divert larger amounts of such sediments close along inshore in such manner as to add valuable new land annually to the public domain, not alone in China but in all countries where large resources of this type are going to waste.
In the vast Cantonese delta plains which we had just left, in the still more extensive ones of the Yangtse kiang to which we were now going, and in those of the shifting Hwang ho further north, centuries of toiling millions have executed works of almost incalculable magnitude, fundamentally along such lines as those just suggested. They have accomplished an enormous share of these tasks by sheer force of body and will, building levees, digging canals, diverting the turbid waters of streams through them and then carrying the deposits of silt and organic growth out upon the fields, often borne upon the shoulders of men in the manner we have seen.
It is well nigh impossible, by word or map, to convey an adequate idea of the magnitude of the systems of canalization and delta and other lowland reclamation work, or of the extent of surface fitting of fields which have been effected in China, Korea and Japan through the many centuries, and which are still in progress. The lands so reclaimed and fitted constitute their most enduring asset and they support their densest populations. In one of our journeys by houseboat on the delta canals between Shanghai and Hangchow, in China, over a distance of 117 miles, we made a careful record of the number and dimensions of lateral canals entering and leaving the main one along which our boat-train was traveling. This record shows that in 62 miles, beginning north of Kashing and extending south to Hangchow, there entered from the west 134 and there left on the coast side 190 canals. The average width of these canals, measured along the water line, we estimated at 22 and 19 feet respectively on the two sides. The height of the fields above the water level ranged from four to twelve feet, during the April and May stage of water. The depth of water, after we entered the Grand Canal, often exceeded six feet and our best judgment would place the average depth of all canals in this part of China at more than eight feet below the level of the fields.