Reanalysis of the daily precipitation concentration index in the Río Grande of Morelia basin

Abstract

The daily precipitation concentration index is a useful tool for the analysis of the statistical structure of rainfall. However, it is necessary to be careful with the data used for its calculation since this index can be sensitive to both the temporal location of the data and the length of the records. Thus, the objective of this work consisted of a re-analysis of the daily precipitation concentration index (CI) in the Río Grande de Morelia basin to determine how the temporal location of the data and the length of the records affect the CI values. In addition to analyzing the behavior of the CI under three different conditions. The results show that the temporary location of the records can affect the value of the CI, increasing it if the last available years are analyzed or decreasing it if records before 1980 are taken. Regarding the length of the records, it was found that the value of this index tends to stabilize in most of the cases studied for record lengths greater than 20 years. The behavior of the CI at the annual level is within that reported in the literature, and at the decade level and for the 30-year, a decrease in its variability was observed. Therefore, it is recommended that in studies of this type, a common recording period be chosen for the analyzes and a length according to the objectives pursued.