Comparison of the behavior of the precipitation concentration index on global and local scale

摘要

The concentration index (CI) has been widely used in recent years to analyze the statistical structure of daily precipitation. This index was proposed by Martin-Vide Int J Climatol 24:959-971 (2004) to explore the contribution of the days of the greatest rainfall to the total amount. However, sometimes, the interpretation of the concentration index could be confusing because depending on the research work consulted, it could be categorized into different levels of concentration. The differences observed in the classifications are due to the distribution of the CI values within each of the regions under study, that is, it is due to local classification. Under these circumstances, it is important to differentiate between the global and local behavior of this index in order to make comparable the results of different research work. According to their definition, the concentration index could be classified intuitively on global manner as: very low concentration (0-0.2), low concentration (0.2-0.4), moderate concentration (0.4-0.6), high concentration (0.6-0.8), and very high concentration (0.8-1). The results show that the observed range of the CI values at a global scale of the countries considered in this work is between moderate and high. On the other hand, at the local scale, the methodologies proposed for the classification of the concentration index show a good performance. The local classification allows for knowing within the range of local variation the conditions of concentration of the precipitation at this scale.