Influences of Geographic Environment - Ellen Churchill Semple (libby ebook reader .TXT) 📗
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A far more modern type of river-dwellers is found in the "shanty-boat" people of the western rivers of the United States. They are the gypsies of our streams, nomads who float downstream with the current, tying up at intervals along the bank of some wooded island or city waterfront, then paying a tug to draw their house-boat upstream. The river furnishes them with fish for their table and driftwood for their cooking-stove, and above all is the highway for the gratification of their nomad instincts. There is no question here of trade and overpopulation.
Pile dwellings and house-boats are a paltry form of encroachment upon the water in comparison with that extensive reclamation of river swamps and coastal marshes which in certain parts of the world has so increased the area available for human habitation. The water which is a necessity to man may become his enemy unless it is controlled. The alluvium which a river deposits in its flood-plain, whether in some flat stretch of its middle course or near the retarding level of the sea, attracts settlement because of its fertility and proximity to a natural highway; but it must be protected by dikes against the very element which created it. Such deposits are most extensive on low coasts at or near the river's mouth, just where the junction of an inland and oceanic waterway offers the best conditions for commerce. Here then is a location destined to attract and support a large population, for which place can be made only by steady encroachment upon the water of both river and sea. Diking is necessitated not only by the demand for more land for the growing population, but also by the constant silting up of the drainage outfalls, which increases the danger of inundation while at the same time contributing to the upbuilding of the land. Conditions here institute an incessant struggle between man and nature;596 but the rewards of victory are too great to count the cost. The construction of sea-walls, embankment of rivers, reclamation of marshes, the cutting of canals for drains and passways in a water-soaked land, the conversion of lakes into meadow, the rectification of tortuous streams for the greater economy of this silt-made soil, all together constitute the greatest geographical transformation that man has brought about on the earth's surface.597
Though the North Sea lowland of Europe has suffered from the serious encroachment of the sea from the thirteenth to the sixteenth century, when the Zuyder Zee, the Dollart and Jade Bay were formed, nevertheless the counter encroachment of the land upon the water, accomplished through the energy and intelligence of the inhabitants, has more than made good the loss. Between the Elbe and Scheldt more than 2,000 square miles (5,000 square kilometers) have been reclaimed from river and sea in the past three hundred years. Holland's success in draining her large inland waters, like the Haarlem Meer (70 square miles or 180 square kilometers) and the Lake of Ij, has inspired an attempt to recover 800 square miles (2,050 square kilometers) of fertile soil from the borders of the Zuyder Zee and reduce that basin to nearly one-third of its present size.598 One-fourth of the Netherlands lies below the average of high tides, and in 1844 necessitated 9,000 windmills to pump the waste water into the drainage canals.599
The Netherlands, with all its external features of man's war against the water, has its smaller counterpart in the 1,200 square miles of reclaimed soil about the head of the Wash, which constitute the Fenland of England. Here too are successive lines of sea-wall, the earliest of them attributed to the Romans, straightened and embanked rivers, drainage canals, windmills and steam pumps, dikes serving as roads, lines of willows and low moist pastures dotted with grazing cattle. No feature of the Netherlands is omitted. The low southern part of Lincolnshire is even called Holland, and Dutch prisoners from a naval battle of 1652 were employed there on the work of reclamation, which was begun on a large scale about this time.600 In the medieval period, the increase of population necessitated measures to improve the drainage and extend the acreage; but there was little co-operation among the land owners, and the maintenance of river dikes and sea-walls was neglected, till a succession of disasters from flooding streams and invading tides in the thirteenth and fourteenth centuries led to severe measures against defaulters. One culprit was placed alive in a breach which his own neglect or criminal cutting had caused, and was built in, by way of educating the Fenlanders to a sense of common responsibility.601
The fight against the water on the coast begins later than that against rivers and swamps in the interior of the land; it demands greater enterprise and courage, because it combats two enemies instead of one; but its rewards are correspondingly greater. The Netherlands by their struggle have acquired not only territory for an additional half million population, but have secured to themselves a strategic position in the maritime trade of the world.
The abundant fertility of river flood-plains inevitably attracts population and necessitates some kind of artificial protection against inundation. The most primitive form of this protection is obvious and widespread, restricted in neither locality nor race. When the flood season converts the flat plain of the White Nile below Gondokora (7° N. Lat.) into an extensive marsh, countless hills of the white ant emerge over the waters. During the dry season, the ants build up their hills to about ten feet, and then live in safety in the upper section during the flood. They greatly surpass in intelligence and constructive ability the human occupants of the valley, the low and wretched Kytch tribe of the Dinka Negroes, who like the ants are attracted by the natural vegetation of the flood-plain, and who use the ant-hills as refuge stations for themselves and their cattle during the flood.602 Elsewhere in Africa the natives are more intelligent, for flood-plain villages built on artificial mounds have existed from the earliest times. Diodorus Siculus tells us that those of ancient Egypt, when the Nile was high, looked like the Cyclades Islands.603 Similar ones are constructed by the Barotse tribe on the upper Zambesi.604 The Niger River, rising in the Foota Jallon and Kong Mountains which form a region of heavy rainfall from February to July, inundates a plain of several thousand square miles for a distance of 250 miles above Timbuctoo. Here again the villages of the agricultural Song-hoi duplicate those of Egypt, built on the same clay mounds, wreathed in the same feathery palms, and communicating with one another only by small boats.605 The same picture is presented by the Yangtze Kiang plain during the summer overflow—low artificial hills rising from the expanse of muddy water and topped with trees and villages, while sampans moored to their base show the means of communication.606 In the broad flood-plain of the lower Mississippi River, the chronicles of the De Soto expedition state that the Indian villages visited stood "on mounds made by art." The Yazoo River Indians, at the commencement of the eighteenth century, had their cabins dispersed over the low deltaic land on earthen mounds made by their own hands. There is also strong evidence that some of the works of the Mound-builders in the "bottoms" of the middle and lower Mississippi served as protected sites for the dwellings of their chiefs.607
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.]
In such organized struggles to reduce the domain of the water and extend that of the dry land, the material gain is not all: more significant by far is the power to co-operate that is developed in a people by a prolonged war against overwhelming sea or river. A common natural danger, constantly and even regularly recurring, necessitates for its resistance a strong and sustained union, that draws men out of the barren individualism of a primitive people, and forces them without halt along the path of civilization. It brings a realizing sense of the superiority of common interests over individual preferences, strengthens the national bond, and encourages voluntary subservience to law.
This is the social or political gain; but this is not all. The danger emanating from natural phenomena has its discoverable laws, and therefore leads to a first empirical study of winds, currents, seasonal rainfall and the whole science of hydraulics. With deep national insight, the Greeks embodied in their mythology the story of Perseus and his destruction of the sea monster who ravaged the coast, and Hercules' killing of the many-headed serpent who issued from the Lernean Marshes to lay waste the country of Argos. Even so early a writer as Strabo states that yet earlier authorities interpreted Hercules' victory over the river god of the Achelous as the embankment of that stream and the draining of its inundated delta tract by the national benefactor.613 So the
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