Assessment of extreme precipitation through climate change indices in Zacatecas, Mexico

Abstract

Climate change and extreme climate events identified worldwide at the local, regional, and global scales have significant impact on ecosystems and on society. In this study, spatial and temporal changes in extreme precipitation events in north-central Mexico were investigated using daily precipitation data from 29 meteorological stations over a period of 54 years (1961–2014). The extreme precipitation events are described using ten of the indices established by the Expert Team on Climate Change Detection and Indices (ETCCDI), which characterize daily precipitation in terms of intensity, accumulation, and duration. The indices were calculated yearly and seasonally. The annual and seasonal trends of the indices were estimated with the Theil-Sen method, and its statistical significance was tested with the Mann-Kendall test (MK). The regional average indices of annual total precipitation from wet days (PRCPTOT), simple daily intensity (SDII), number of heavy precipitation days (R10), number of very heavy precipitation days (R20), and consecutive wet days (CWD) had downward trends, but only the last was statistically significant. The regional average of the indices of maximum 1-day precipitation (RX1day), maximum 5-day precipitation (RX5day), number of very wet days (R95p), number of extremely wet days (R99p), and number of consecutive dry days (CDD) showed upward trends, all statistically non-significant. The annual regional average PRCPTOT has decreased at a rate of − 6.20 mm/decade. The decrease was concentrated mainly in central and southern Zacatecas and is associated mainly with the decrease in autumn and summer precipitation. The annual regional average CDD index had increasing trends; 58.6% were statistically significant and concentrated mainly in central and southern Zacatecas. In terms of the general behavior of the PRCPTOT, RX1day, RX5day, R95p, R99p, CDD, and CWD indices, we observed that the precipitation events are decreasing but are becoming slightly more intense. The results will contribute to a better administration of water resources in the state of Zacatecas, Mexico, under the influence of climate change.