Low flows quantification and regionalization in North West Algeria

Low flow hydrological regimes are crucial for an efficient development of water resources management tools, especially in those areas stressed by the combination of a dry climate and an excessive water demand, such as the Mediterranean basins. A lot of effort has been made by the worldwide scientific community toward the prediction of low flows features in ungauged catchments. The aims of the present study are: (1) the quantification of low flows characteristics, in particular with regard to the BFI and (2) the application of a simple regional approach to predict the BFI at ungauged sites. The investigated area is located in North West Algeria and has an extension of about 130,000 km². The relevant extension and the poorly dense monitoring network, which consist in 24 hydrometric stations, require the identification of homogeneous regions, for further application of simple linear regional regression models. Regions delineation is accomplished through the Principal Component Analysis method (PCA) and the cluster analysis, based on physiographic and climatic data. Three significantly different homogeneous areas have been identified, and comparisons between global and local regional multiple linear regression models indicate a large percentage of BFI explained variance in each area.