domingo, 22 de agosto de 2010

FOR REFLECTING ABOUT

PHENOMENA OF THE CHILD AND THE CHILD


El Niño and La Niña are the names of two atmospheric-oceanic phenomena that occur cyclically varying periods of 2-7 years. Have a higher incidence in the Pacific Ocean and around the latitude of Ecuador. Its effects are regional and global status as transforming the climate of almost the entire Earth. For example, during the 1997-1998 El Niño event in Mongolia temperature reached 42 ° C and precipitation in central Europe caused a major flood of the century.


This phenomenon severely affects the social, economic and political status of countries, altering its production cycle and socio-economic growth. In humid areas usually originate prolonged droughts in arid areas are produced torrential rains and waves of heat or cold in different parts of the world.
Usually, this means heavy losses in economic activities, especially in primary activities, so much more to affect developing countries where they are the foundation of its economy. For example:

• drought, increase the mortality of livestock and forest fires that pollute the environment and cause loss of biodiversity.

• Torrential rains cause severe flooding and mudslides and rocks; increasing the temperature of the water away from some fishing grounds important fish species for their commercial value thus impeding fishing.

• other activity is tourism affected, source of income for these countries.


Now, how is the atmosphere-ocean circulation in normal times?

The trade winds blow from east to west and drag the warm waters of the Pacific Ocean to its western sector. For this reason, Asian and Australian coasts, the sea is about 50 cm. higher and 70 C to 90 C warmer than on the American coasts. This causes:



• off the coast of Southeast Asia during the summer, has increased evaporation of water. The monsoon winds carry moisture causing rainfall over the continent, and allow the practice of intensive agriculture, which provides food for millions of people;

off the American coast, where the cold currents circulating in California and Humboldt, it is hard to evaporation. This produces a climate on the coast is arid and warm surface waters are not very thick. This process allows the rise of deep waters with nutrients that feed the abundant fish, generating one of the most productive fishing areas in the world

When El Niño occurs is an alteration in atmospheric pressure over the Pacific Ocean near Tahiti decreases and increases in northern Australia. The trade winds weaken or even disappear resulting in both the atmosphere and oceans, large anomalies. The trade winds are not strong to drag warm surface waters to the coasts of Asia, then return to American shores forming the counter El Niño. This results in atmospheric and oceanic effects contrary to those normal times. That is, in the Asian coasts are droughts, forest fires and so forth. In turn, on the American coasts are unleashed major tropical storms, landslides and floods that carry.



The girl in turn, causes a reverse mechanism that produced El Niño atmospheric pressure in Tahiti and low rises in Australia, restoring the normal flow direction but more strongly. The trade winds blow more strongly than the normal crawling toward the western Pacific larger volume of water, causing it to draw out more of cold water in the eastern Pacific. This leads to above normal rainfall in Asia, Australia and even South Africa. Meanwhile, the temperature drops on the American coasts and increasing aridity and the frequency of hurricanes in the U.S. central plains

SCHOOL OF NATURAL DISASTERS

Have been classified more than 20 disaster risks are capable of producing. Ranging from earthquakes to fog and mist, but the most important are:

Hydrologic stormy waves, tsunamis
Weather: Floods, hurricanes, cyclones, typhoons, tornadoes, drought, frost, hailstorms, cold waves, heat, snow and winter storms.
Geophysical: earthquakes and volcanoes, avalanches, landslides, mudslides, avalanches.
Biological: red tide (appearance on the surface of water mussels, clams, etc.. Who are carriers of toxins and alter the food chain)

Natural disaster


The wind, waves and all the natural dynamics show us the complex interrelation between the lithosphere, hydrosphere, atmosphere and biosphere. Much of this dynamic is almost imperceptible, such as erosion or sedimentation caused by wind, rivers, glaciers, and so on. However, in other cases, the behavior is violent natural elements, such as earthquakes and volcanic eruptions, threatening the companies, their assets or activities.


An earthquake, hurricane or other extreme event of nature becomes a disaster or catastrophic when human losses or economic causes. That is, natural disaster is called only when the social or economic problem is triggered by a phenomenon of nature. loe Golden said "a potential danger becomes disaster if it occurs where people live."

The consequences of natural disasters must be viewed not only from the point of view of the lives lost, but also from an economic standpoint, they constitute an obstacle to economic and social development of the region, especially in countries development. In them, a disaster can result in a reduction of gross national product for several years, for example, flood drag the topsoil and takes years to recover. It has been estimated that the gross national product losses due to disasters can be, proportionally, 20 times higher in developing countries than in developed nations.

The FAO has estimated that the drought in the 70s in the Sahel (Africa) reduced to half the gross national product (GNP) of the region's countries: Burkina Faso, Chad, Mali, Mauritania, Niger and Senegal.

Disasters can have consequences later, ie can only be evaluated over several years. A drought or flood can affect the economy of the region or a country in a way that affects the quality of life or health of its population for several years. According to the Office of the Coordinator of United Nations Disaster Relief (UNDRO), floods in the Philippines in 1972, delayed the development efforts between three and five years.

A major cause of the slow recovery and reconstruction in developing countries after a disaster, you do not have property seized as many developed countries. Hurricane Andrew, which struck the U.S. in 1992, led to 30,000 million dollars in losses, but 75% were carried out by insurance companies. By contrast, floods and landslides that swept China in 1996, caused an economic loss of 24.000 billion dollars, but their insurance did not reach 2% of losses.



In addition, after the phenomenon, the victims need not only material assistance but also psychological support: studies show an increase in depression, alcohol consumption and to increase the suicide rate.

A point to note is that disasters or disasters caused by natural events are increasing and entail losses in the millions, but scientists who observe, record and analyze the natural dynamic state that the frequency of extreme cases has not increased significantly. This is due in large part to rising world population and poverty, as the where and how man built their homes may increase the risks for both physical (injuries and deaths) and social and economic, which are slow to recover.



Currently, at least one fourth of humanity lives in areas vulnerable to disasters, especially in developing countries. In them, people settled their homes in areas prone to such disasters, for example on the slopes of the mountains, where avalanches can drag entire villages, as happened in El Nevado del Ruiz (Colombia), or in the beds of rivers that when they increase their flow, overflow and cause serious flooding.

Another element to consider is that many of the actions of human beings as deforestation and pollution compound the effects of natural phenomena. Cleared forests on the slopes of the mountains favor avalanches or landslides, the sediment fill in riverbeds, causing overflow more frequently