Watershed Size, an Alternative or a Misguided Parameter for River’s Waterpower? Implementation in Macedonia, Greece

This paper examines the effectiveness of using the watershed size, as an alternative stand-alone parameter that substitutes the river’s waterpower. The waterpower of each river is the main factor shaping the surface waters and is directly related with the water cycle balance. Watershed size was used by the (WFD) Water Framework Directive 2000/60 for Community action in the field of water policy as an alternative for the river’s waterpower. In this study, 49 watersheds of Macedonia, Greece were examined and classified by their watershed size, according to the WFD. The mean annual temperature and precipitation was estimated at each one of these catchments based on data from 64 different meteorological stations, which belong to the Ministry of Rural Development and Food and the examined time period was thirty years (1974–2004). The geology of Macedonia was classified in 2 classes at scale 1:500,000 and in 6 classes at scale 1:50,000. The corresponding mean annual surface runoff was estimated respectively to each geological classification. The results were compared with the suggested modified WFD watershed size classification and all were evaluated respectively.