Summer drought in the el cielo biosphere reserve and its environment, Tamaulipas, Mexico

Abstract

The study evaluated the intensity and frequency of droughts in the El Cielo Biosphere Reserve and compared their inter-annual variability using monthly rainfall records between 1922 and 2012. Droughts were quantified as the relative decrease of the monthly precipitation polygon during the rainy season. 86% of the summers analyzed by considering eleven stations featured droughts. The intensity of the drought was low in 55.6% of those summers, medium in 23.1%, and severe in 57%. The droughts have a cyclic behavior, with periods of nine years: they begin with low intensity, increase to medium or severe intensity, and then decrease to low. Trend analysis does not show an increase the phenomenon.