Historical precipitation patterns in the South-Southeast region of Mexico and future projections

Abstract

This study analyzed climate change scenarios and their potential impact on water availability for the South-Southeast region (SSR) of Mexico. Precipitation patterns were examined using the Standardized Precipitation Index for three emissions scenarios, Representative Concentration Pathway (RCP) 4.5, RCP 6.0, and RCP 8.5, during the periods of 1960-2016, 2015-2039 (near future), and 2075-2099 (far future). Historical changes in precipitation in the SSR indicated the presence of dry and wet events driven by El Niño-Southern Oscillation, the Pacific Decadal Oscillation, and the Atlantic Multidecadal Oscillation, which are the regional climate modulators. However, the impact of these phases has not been quantified for the future. The results of our climate change projections show that the Grijalva and Usumacinta rivers and surrounding regions (Chiapas and Tabasco) will have an increase in the percentage of dry and wet events in the near future (2015-2039), while there is a medium to low probability of this occurrence in rest of the SSR. By 2075-2099, Grijalva and Usumacinta will continue to have a high probability of dry events due to climate change, and the Yucatan will also exhibit this behavior. RCP 4.5 was projected to be the wettest scenario for the study area, while RCP 8.5 projected an increase in dry events in the area during both periods (2015-2039 and 2075-2099). RCP 6.0 projected a drier 2015-2039 and wetter 2075-2099.