Sequia En Ingels

Drought in Mexico

Given the frequency and intensity with which the phenomenon of drought has been present in our territory, over the thousands of years that span both history and prehistory of the country, we could limit them as relatively "normal" situations within own climatic oscillations of this area, which is easily detected in periods of one or two decades.

Droughts are inextricably linked to the absence, delay or lack of rain, so for the purposes of this article, we define as "significantly smaller than average rainfall or a specific value for a period of time."

The parameters for evaluation are provided to us rates average annual rainfall in millimeters. For example, the rate of average annual rainfall on the planet is 811 mm; 1028 mm and 3292 mm in France in Java. The wettest place in the world is Hawaii with 8500 mm and the driest, the Atacama Desert in Chile, which until 1971 had not fallen a drop of water in 400 years.

In Mexico, the overall average annual rainfall is 700-710 mm, a fairly low rate that puts us on the edge of rainfed agriculture with low yields, which marks as the 800 mm lower fee. In our country, areas with different rainfall regimes ranges ranging from 50 to 100 mm in Baja California and part of Sonora, to 4500 mm in northern Chiapas and Soconusco are presented; 3500 mm in southern Tabasco, 2500 mm in the southwest of Veracruz, Tlaxcala 800 mm, 700 mm in the center of Oaxaca and Sinaloa, Zacatecas and 400 mm.

In a classification developed by García Quintero to Mexico, states that the type of arid climate, which is set with an average annual rainfall of less than 800 mm, affects 52.1 percent of the total land area; semi-arid climate, which ranges from 800 to 1200 mm, to 30.6 percent; the semi-wet, from 1200 to 1500 mm, 10.5 percent and humid, above 1500 mm, to 6.8 percent. This crude registration defines 82.7 percent of Mexican territory as arid and semiarid shows major water shortages in general, as a nation, we suffer.

This entails a series of economic, political, social and environmental problems are compounded considerably when rains expected in each cycle, few they may be, are delayed fall in smaller quantities or simply fail.

Empirically, rural men consider that one in four years there will be droughts, but sometimes can be put together two or three "bad" years. For our part, in some research we have conducted in the Department of Man and Environment of the UAM-Xochimilco, have been calculated for drought cycles that we have divided into three groups:

The first relates to periods of between two and seven years corresponding to the quasi-biennial oscillation of the weather event known as El Niño; the other two groups are closely related to two cycles of solar activity: the first one between 10.3-11 years Wolf named cycle and the second, 23.2 years, known as the Hale cycle.

The researcher Enrique Florescano has

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