Analysis of the trends in precipitation and precipitation concentration in some climatological stations of Mexico from 1960 to 2010

Analysis of precipitation trends as well as the observed trends in precipitation concentration can be useful tools for the identification of natural hazards. This study aimed to analyze the trends in precipitation and precipitation concentration at the seasonal and annual levels in Mexico from 1960 to 2010. To do this, an entropy-based concentration index was used to calculate the concentration of precipitation at 44 climatological stations distributed throughout the country. The trend analysis was developed based on the Mann–Kendall test. There were fifteen significant precipitation trends at the annual level, and the numbers of positive and negative trends were nearly even. The interannual average of the concentration index ranged from 0.084 to 0.265, although extreme values of up to 0.56 were observed at the annual level and of up to 1 at the seasonal level. There were more positive trends than negative trends in the concentration index. The comparison of the trends of the precipitation and the concentration index showed an increase in precipitation at some stations with an associated decrease in the concentration index. On the other hand, decreases in precipitation at other stations were accompanied by increases in the concentration index. The first case did not seem to represent risk because the conditions suggested a more regular precipitation pattern. However, the second case could be considered a cautionary indicator, especially in the northern region, where it could signal the potential for drought.