The Mississippi River is one of the world’s major river systems in size
The Mississippi River is one of the world’s major river systems in size, habitat diversity and biological productivity. It is the second longest river in North America, flowing 2,350 miles from its source at Lake Itasca through the center of the continental United States to the Gulf of Mexico. The Missouri River, a tributary of the Mississippi River, is about 100 miles longer. Some describe the Mississippi River as being the third longest river system in the world, if the length of Missouri and Ohio Rivers are added to the Mississippi's main stem.
When compared to other world rivers, the Mississippi-Missouri River combination ranks fourth in length (3,710 miles/5,970km) following the Nile (4,160 miles/6,693km), the Amazon (4,000 miles/6,436km), and the Yangtze Rivers (3,964 miles/6,378km). The reported length of a river may increase or decrease as deposition or erosion occurs at its delta, or as meanders are created or cutoff. As a result, different lengths may be reported depending upon the year or measurement method.
Length
For reasons mentioned above there are competing claims as to the Mississippi's length. The staff of Itasca State Park at the Mississippi's headwaters say the main stem of the river is 2,552 miles long. The US Geologic Survey has published a number of 2,300 miles, the EPA says it is 2,320 miles long, and the Mississippi National River and Recreation Area suggests the river's length is 2,350 miles.
Width
At Lake Itasca, the river is between 20 and 30 feet wide, the narrowest stretch for its entire length. The widest part of the Mississippi can be found at Lake Winnibigoshish near Bena, MN, where it is wider than 11 miles. The widest navigable section in the shipping channel of the Mississippi is Lake Pepin, where it is approximately 2 miles wide.
Speed
At the headwaters of the Mississippi, the average surface speed of the water is about 1.2 miles per hour - roughly one-third as fast as people walk. At New Orleans the river flows 3 miles per hour on average.
Mississippi River Watershed
Mississippi River Watershed
The Mississippi River watershed is the fourth largest in the world, extending from the Allegheny Mountains in the east to the Rocky Mountains in the west. The watershed includes all or parts of 31 states and 2 Canadian Provinces. The watershed measures approximately 1.2 million square miles, covering about 40% of the lower 48 states.
Water Supply
Communities up and down the river use the Mississippi to obtain freshwater and to discharge their industrial and municipal waste. We don't have good figures on water use for the whole Mississippi River Basin, but we have some clues. A January 2000 study published by the Upper Mississippi River Conservation Committee states that close to 15 million people rely on the Mississippi River or its tributaries in just the upper half of the basin (from Cairo, IL to Minneapolis, MN). A frequently cited figure of 18 million people using the Mississippi River Watershed for water supply comes from a 1982 study by the Upper Mississippi River Basin Committee. The Environmental Protection Agency simply says that more than 50 cities rely on the Mississippi for daily water supply.
Commerce
Agriculture has been the dominant land use for nearly 200 years in the Mississippi basin, and has altered the hydrologic cycle and energy budget of the region. The agricultural products and the huge agribusiness industry that has developed in the basin produce 92% of the nation's agricultural exports, 78% of the world's exports in feed grains and soybeans, and most of the livestock and hogs produced nationally. Sixty percent of all grain exported from the US is shipped on the Mississippi River through the Port of New Orleans and the Port of South Louisiana.
About the Author
0 komentar