Analysis of behaviour and relationship of four daily precipitation concentration indices according to Mexico's precipitation

In recent years, the field of precipitation concentration has garnered significant research interest owing to the importance of precipitation for economic activities related to agriculture, energy production, and drinking water supply management. For the study and characterization of precipitation concentration, different approaches have been defined, such as consideration of the concentration index (CI), Theil index (TI), Q index (QI), and precipitation concentration degree (PCD) index. However, in the literature, there is only one study that evaluates the performance of the CI and TI in conjunction on a spatial basis. Another study evaluates the behaviour of the QI and PCD indices on a temporal basis. Thus, the objective of this work was to analyse the behaviour of the four indices both on temporal and spatial scales according to Mexico's precipitation. Results show that the four indices can detect, in a similar manner, the concentration degree of regions with different rainfall regimes, each within its own variability. A lower range of variability was found for the TI, while the highest was found for the CI and the PCD index. In addition, the PCD index showed high sensitivity within its concentration degree when calculated for different time intervals. The results of the temporal and spatial correlation analysis show a very high correlation between the CI and TI, and moderate and low correlations among the other indices. Low correlations can be attributed to the differences in the theoretical bases of each index. Although low correlations were shown for some indices, the results indicate that these can be used in a complementary manner to improve the precipitation concentration analysis on temporal and spatial scales.