Delimiting homogeneous regions using the multifractal properties of validated rainfall data series

•Regional frequency analysis of extreme annual rainfall data series has been done.•Several quality control methods were previously applied for validating the datasets.•A multifractal approach was used to characterize validated daily rainfall data.•Homogeneous regions were delimitated using the multifractal properties of rainfall.•This work shows a new tool based on multifractality to form homogeneous regions. In this work, a regional frequency analysis of extreme annual rainfall data in Malaga (Southern Spain) has been performed. Rainfall records have been validated, applying various quality control tests as a pre-requisite before their use, ensuring their reliability and discarding anomalous data. For grouping the stations into potential homogeneous regions, the multifractal properties of daily rainfall data series recorded at 72 locations have been studied. The scaling of the rainfall moments has been analyzed and the empirical moments scaling exponent functions have been obtained. The corresponding multifractal values have been used to group stations into regions, resulting some of them homogeneous.