A year after the Mississippi River swelled to near-historic proportions and flooded farms and homes from Illinois to Louisiana, the level along the waterway's southern half is so low that cargo barges have run aground and their operators have been forced to lighten their loads.
Wide, sandy strips of shoreline usually invisible even in the low season are now exposed, shrinking the river's width and affecting the way tow captains navigate.
Such is life along the nation's main inland waterway, where millions of tons of goods are shipped every year, some of which end up as exports departing from south Louisiana ports. Those who make their living along the Mississippi learn to adapt to the river's fickle nature.
"It's remarkable, but it's completely normal," said Jim Pogue, spokesman for the Army Corps of Engineers in Memphis. "You get a low river, you get a high river, but it's completely normal."
There isn't much man can do to deal with the exceptionally low river, which at Memphis, is just about 6 feet above the record low.
"Pray for rain," said Tommy Hart, director of the port in Greenville, Miss. "I'm not a big fan of rain, but this time I am."
AP
In this July 13, 2012, photo, the Memphis Queen riverboat moves up the Mississippi River, in Memphis, Tenn. A year after nearly record floods, the Mississippi River level has dropped so low that it's beginning to affect commercial operations. Port managers worry that their passages to the river could fill up with silt, and barge operators may have to lighten their loads. (AP Photo/Nikki Boertman)
Close Aside from that, the best coping mechanism is careful navigation. With the river this low, the channels are shallower and narrower, presenting problems for barges loaded with coal, grain, iron, steel, sand, gravel and more. They must reduce their loads to avoid bottoming out and take extra care not to collide when passing another string of barges in the thinner channel.
Also, low water at docks and terminals makes it more difficult to load or unload material, as ships have trouble getting close enough to docks. Companies must get permits from the Army Corps to dredge near their docks to find deeper places to load and unload.
The National Weather Service said the Mississippi River gauge in Memphis was at minus-4.8 feet on Friday, but there's no need to panic. The "minus" reading does not mean the river is dried up â€" it's just a measurement based on how the river gauge is designed. Essentially, the reading means the river level is far below normal.
That low level stands in contrast to the flood of 2011, which saw the Mississippi fall about a foot short of the record crest of 48.7 feet set in 1937. The National Weather Service has set the official crest of last year's flood at 48.03 feet on the Memphis gauge.
"It's basically just the opposite of last year," Pogue said.
One reason for the difference is a lack of rainfall in the Ohio River valley and the north Mississippi River basin, said Ryan Husted, a National Weather Service meteorologist in Memphis. Sections of Tennessee and regions to the north are experiencing drought conditions. Most areas in the Mid-South are 10 inches or more below normal for rainfall for the year, the weather service said.
Lower-than-normal snowfall levels over the northern plains this winter are also an issue, Husted said. Less snow means less water from melted snow making its way into the Mississippi and the rivers that feed it.
The record low on the Memphis gauge is minus-10.7, set during a severe drought in 1988. That year, a stretch of river about 100 miles south of Memphis was temporarily closed, Pogue said.
Near Greenville, Miss., more than 700 barges were backed up on the river. Crews dredged day and night to make the river deep enough for traffic to resume.
沒有留言:
張貼留言