Changes in Aridity across Mexico in the Second Half of the Twentieth Century

Abstract

Six regions in Mexico, with typical interannual changes in the aridity index, have been defined by the 1951–2001 meteorological dataset. Peak months of rainfall differ within the regions. Most of the land in the Mexican terrain has had a slow aridization since the early 1980s. The decline in the aridity index in the early 1950s and late 1990s was caused by droughts in the area. The distinctive features of the aridization of Mexican dry lands are characterized by steady and extensive droughts during 1948–57, 1960–65, and 1994–2003 in the second half of the twentieth century. During the drought of 1951–57 substantial aridization in most of the dry lands was observed, including the Sierra Madre Occidental, Sierra Madre Oriental, and Mexican Altiplano. Aridization of dry lands during the drought in 1960–65 affected mostly the southern part of the Mexican Altiplano, the Sierra Madre del Sur, and the Yucatán Peninsula. For the drought in the 1990s, one special feature of the aridization was its propagation primarily beyond the Mexican Altiplano. Increased aridization of dry lands caused by long-term droughts during the last decade of the twentieth century did not result in a sizeable shift of the southern boundary of the dry lands. The only exception is the southern boundary (aridity index = 0.75) in the state of Sinaloa. In this area, the boundary moved southward and aridization intensified. The results obtained here can be used in studies of possible anthropogenic impact on the drought of the twentieth century’s last decade in Mexico, which includes changes in land use.

Ecological Water Stress under Projected Climate Change across Hydroclimate Gradients in the North-Central United States

“…Using their classification scheme of dryland types, the proportion of our study area classified as semiarid, arid, and hyperarid (MI , 0.65) was projected to increase by ;31% under relatively warmer projections represented by CCSM4 and IPSL-CM5A-MR. The findings of our study showed expansion of drylands associated with an increase in aridity resulting in potential aridification coupled with human modifications in this area (Reynolds et al 2007;Tereshchenko et al 2015;Adhikari and Hansen 2018). This is particularly true for the temperate prairies, west-and south-central semiarid prairies, and southeastern plains.…”

“…It is often estimated as the ratio between precipitation (PPT) and potential evapotranspiration (PET) and referred to as the moisture or aridity index (hereinafter MI) (Rind et al 1990). The MI indicates either a potential surplus or deficit of available surface water content in a given environment and can be used to characterize, for example, spatial extent of drylands (defined as MI , 0.65) at subcontinental scale (Tereshchenko et al 2015). Across many regions of the globe, increased temperatures from anthropogenic global warming have increased PET and reduced MI (Feng and Fu 2013).…”

Effect of the Trans‐Volcanic Axis on meridional propagation of summer precipitation in western Mexico

“…In southeastern Mexico (Figure 4), station selection displays the characteristic double precipitation peak associated with the MSD. Note that the double peak signal is evident from the TVA southward as previously reported (see, e.g., Tereshchenko et al ., 2015, fig. 6b), although Karnauskas et al .…”

“…Most inland stations show a July maxima, while the peak is in August along the coast (see Brito‐Castillo et al ., 2010, fig. 1 and Tereshchenko et al ., 2015, fig. 6a).…”

Modeling the relationship between malaria prevalence and insecticide-treated bed net coverage in Nigeria using a Bayesian spatial generalized linear mixed model with a Leroux prior

“…The aridity index, which is defined as the ratio of annual precipitation to annual potential evapotranspiration, is a key parameter in drought characterization [ 16 ]. It is indexed between 0 (most arid) and 300 (most wet).…”