Panama Canal CLOSES

The following is an article from CNN talking about how the Panama Canal had to close due to heavy rain and floods:


Panama Canal reopens after flooding 

The Panama Canal reopened Thursday after heavy rains and flooding prompted its closing for only the third time in its storied 96-year history.

Officials closed the canal around noon Wednesday after heavy rain in the Chagres River area, caused water behind the Gatun Dam -- which creates Lake Gatun, a significant part of the canal -- to rise.

The canal was reopened 17 hours later.

The last time the canal closed was in 1989, after the United States invaded Panama to topple strongman Manuel Noriega. Landslides forced the canal to close for several months from late 1915 to mid-1916, just months after it opened.

The 48-mile canal is a key conduit for shipping between the Pacific and Atlantic oceans. The canal was built from 1904 to 1914 by the United States, which had sole control over the channel across the Panamanian isthmus until 1979. Then, after 20 years of joint U.S.-Panama control, the Panamanian government assumed administration on December 31, 1999.

Floods actually REDUCE nutrients in soil

I was surprised to find out that floods actually REDUCE the nutrients in the soil. Here is an excerpt from an article on the topic:


"Field observations were performed to determine the effects of flood flow on the geometrical and chemical characteristics of flood plain soil and the distribution of riparian vegetation in a gravel river. The results of the observations show a decrease in the amounts of the particulate nutrients in the flood plain soil during fairly large flood, because the fine sands that serve as a nutrient source were removed by the flood flow. Numerical simulations for the transport of suspended sediments were performed by varying the peak discharge of the flood, and the change of the particulate nutrients in flood plain soil was estimated by using the results of the simulations. The numerical analysis predicts the reduction of the particulate nutrients in the flood plain soils well. The particulate nutrients on the flood plains decrease if the discharge exceeds the flood of approximately 2 year return period in the observation area."

website: http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=JHEND8000131000011000950000001&idtype=cvips&gifs=yes&ref=no