The Hoover Dam

Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the US states of Arizona and Nevada. It was constructed between 1931 and 1936, and was dedicated on September 30, 1935, by President Franklin Roosevelt. Its construction was the result of a massive effort involving thousands of workers, and cost over a hundred lives.  Such a large concrete structure had never been built before, and some of the techniques were unproven. The torrid summer weather and the lack of facilities near the site also presented difficulties. Hoover Dam impounds Lake Mead, and is located near Boulder City, Nevada. Although mainly intended to control floods and provide irrigation water, the dam's generators provide power for public and private utilities in Nevada, Arizona and California.

Typhoon Fanapi makes landfall in Mainland China after devastating Taiwan, leaving at least 72 people dead.  The picture shows the path the typhon has taken so far. This post will be expanded sometime.

Today on September 27 is World Tourism Day

Also on this date in 1777 in the American Revolutionary War: Lancaster, Pennsylvania, became the capital of the United States for one day as members of the Continental Congress fled Philadelphia, which had been captured by the British.

Geo-terms

Evapotranspiration- The loss of water directly from the ground, water surfaces and vegetation. Evaporation is thephysical process where moisture is lost directly into the atmosphere from water surfaces and the soil due to heat and air movement. Transpiration is thebiological process where water is lost from a plant through stomata on its leaves.
Precipitation- Rainfall on an area. This is the greatest contributer of water in the water cylce and drainage basin system.   Generally the greater the intensity of a storm the shorter its duration.
Interception- When water is stopped from reaching the ground by factors such as vegetation. At the start of a rainfall the vegetation will shelter the ground below, this is greater in a wooded area or where tree crops are grown. If there is enough vegetation and the rainfall is short or light then much if the water may never meet the ground.
Infiltration- I most areas overland flow is rare due to the soil taking in water. The maximum rate at which water can pass through the soil is called its infilltration capacity, the rate of infilltration depending on the amount of water already in the soil, and the structure and type of the soil.
Percolation- Percolation is the constant movement of water through the underlaying soil and rock, the action of which creates ground water storage. Water may be transferred laterally as groundwater flow or baseflow.
Channel flow- Although some rain does not reach the river the majority does through either surface run-off, throughflow or groundwater flow. Once in the river its is known as channel flow.

New Zealand Earthquake

Almost two weeks ago a 7.0 magnitude earthquake struck New Zealand's South Island. Two thirds of the buildings in the area's capital, Christchurch were damaged but luckily there were no casualties. New Zealand lies at the southern end of the Pacific "Ring of Fire", the boundry of the Pacific and Indo-Australian tectonic plates. As a country New Zealand experiences over 14,000 earthquakes a year, though only about 150 are noticable.

National parks of the seas

Fifteen new "national parks of the seas" have been created around the coast of England where fishing and offshore windfarms are restricted. The most famous of the protected areas are the reefs of Lizard Point and Land's End (Cornwall) containing species such as sponges, squid and coral. Other include the Thames Estuary and Liverpool bay.

More than 2000 people have been killed with hundreads of thousands stranded by the annual moonsoon rain in Pakistan. These floods have destoryed millions of hectacres of crops, overun towns and villages and demolished bridges and roads. Due to food shortages famine is spreading as long as diesease such as cholera due to polluted water supplies. It has been estimated  that over 21million people are injured and homeless as a result, a total which is greater than that of the people affected by the boxingday tsunami, the kashmir earthquake in 2005 and the recent Haiti earthquake combined however I feel compared to these, especially the Haiti earthquake very little is being done to provide aid for the Pakistani people.