A study of historical droughts in southeastern Mexico

A catalog containing an unprecedented amount of historical data in the southeastern part of Mexico covering almost four centuries (1502-1899) is used to construct a drought time series. The catalog records information of agricultural disasters and includes events associated with hydrometeorological phenomena or hazards whose effects were mainly felt in the agricultural sector, such as droughts. An analysis of the historical series of droughts in southeastern Mexico for the period 1502-1899 is performed. The highest drought frequency occurred around the years 1650, 1782, and 1884; no droughts were reported around 1540, between 1630 and 1640, along the largest time lapse of 1672-1714, and between 1740 and 1760. From 1760 until the end of the period of study droughts definitively occur more often than they did from similar to 1550 to 1760. In addition, most droughts lasted for 1-2 yr. Analyzing the frequencies of the drought time series it is found that the most conspicuous cycles are similar to 3-4 and 7 yr, although cycles of similar to 12, 20, 43, and 70 yr are also evident. The relation between droughts and El Nino events indicates that 38% of droughts are associated with El Nino. Sea surface temperature changes, the Southern Oscillation index, and solar activity leave their signals in the southeastern part of Mexico, with the signs in Oaxaca clearer than in the Yucatan Peninsula. However, the dominance of some phenomena over others depends on the time scales considered.