Assessment and classification of the interannual variability: Application in the Ebro basin

Abstract

The interannual variation of the water discharge is one of the main characteristics that defines the behavior of rivers. The magnitude of this irregularity must be taken into account in managing the flow of watercourses. Therefore, it is desirable to establish a classification of this interannual variation of rivers, by using simple procedures. The aim of this work is to develope a proposal of categorization of the interannual variation in well defined and contrasted types. First of all, it is necessary to determine a simple and accurate method to obtain interannual irregularity values, from the series of traffic counts data. Thanks to the implementation of this proposal in the Ebro's Basin rivers, it is possible to distinguish between 5 levels or categories of the interannual variation, with a geographical distribution marked by different factors. This shows a strong contrast between the rivers on the left and right banks of the Ebro.