Adirondacks New York Harbor Navigability Hudson River

Science project idea on the effect of the forests of the Adirondacks upon New York harbor and the navigability of the Hudson River.

Effect of the Forests of the Adirondacks Upon New York Harbor and the Navigability of the Hudson River

In order that a harbor may be of the greatest value, a certain amount of dredging must be done to keep the channels free of sand and mud. The origin of this material will be understood by anyone who has noticed the appearance of the water in a small stream after a rainstorm. If this small stream empties into a large body of water, it will be noticed that the mud and sand, which is being carried, is dropped.

Streams everywhere are wearing away the land and carrying it to the ocean. This is the cause of much of the irregularity of the land surface. Each little stream forms a ravine or valley of its own, carrying away the particles of earth and rock which have been loosened by changes of temperature, by the freezing of water in crevices, or by the action of the oxygen or carbonic acid of the air. The action of these agencies is known as weathering. These particles, carried along by the swiftly moving water, help to wear away the bed of the stream; this is known as erosion. Thus we see that the land is gradually being carried to the ocean, where it is dropped as soon as the velocity of the water is checked by coming in contact with the greater body of water. Nearly all the streams that form the Hudson River begin in the Adirondack Mountains, about 3000 feet above sea level. What must be true of the velocity of the water of these streams? As the rainfall in the Adirondacks is not evenly distributed throughout the year, what would you expect to be the condition of the streams during the season of great rainfall and at the time of the melting of the snow? What would you expect to be the result when this water meets the sluggish current of the tidal portion of the Hudson, and when the tidal current from the river meets the water of the harbor?

You will be surprised to learn that the streams are not nearly so flooded, and that there is not so much sediment deposited as you would imagine. Our consideration of the effect of forests upon water-supply areas gives us the key to the explanation. The Adirondack Mountains are heavily forested. What effect does this have upon the volume of water in its streams ? What also will be the effect, upon the power of the streams to accomplish erosion and to carry mud, sand, and rocks? What do you think would be the result of cutting the forests from this mountainous region as affecting the navigability of the Hudson River and New York harbor?

In parts of the country from which the forests have been removed, great floods occur in the rainy periods of the year, while at other times the navigable streams become too shallow to permit the passage of boats. Their navigability can be maintained throughout the year only by the expenditure of large amounts of money for the purpose of dredging the channels and of building dikes and dams.

These conditions are especially true of the Ohio River and its tributaries. A large part of the drainage area, which was at one time densely wooded, has developed into a rich agricultural region necessitating the removal of most of the forests. As a result, during the summer there is almost no water except in the larger streams, while in the spring they overflow their banks, causing much damage to property and often loss of lives.