Abstract

MENDEZ GONZALEZ, Jorge; NAVAR CHAIDEZ, José de Jesús  and  GONZALEZ ONTIVEROS, Vladimir. Analysis of rainfall trends (1920-2004) in Mexico. Invest. Geog [online]. 2008, n.65, pp.38-55. ISSN 2448-7279.

In this study the non parametric Mann-Kendall test was used to identify trends in seasonal rainfall recorded in Mexico. A total of 789 climatological stations distributed throughout most of Mexico were analyzed during 1920-2004. A principal component analysis was used to obtain regions with homogeneous seasonal rainfall. Results show significant changes in the trends of summer rainfall. Geographically, rainfall has increased 1.8% per year in the arid and semi-arid regions, while an increased of 0.9% per year has been observed in the tropical humid parts of the country. Also, a 1.2% decrease of total annual rainfall occurs for both humid and dry regions at a regional and consistent scale. The high numbers of meteorological stations with a significant rainfall increase (p<0.1) were found in arid and semiarid regions of the country. Every decade there are increases of 30 mm during summer whilst there are only 8 mm every decade during winter.

Keywords : Precipitation; trends; magnitude; region; regime; Mexico.