“…A review of the literature suggests that catchments can be classified based on river morphology [ 30 ], river/flow regimes [ 1 , 25 ], hydrologic similarity indexes [ 3 , 5 , 6 , 14 , 16 , 18 , 31 , 32 , 33 , 34 , 35 ], hydroclimatic factors [ 11 , 36 ], ecohydrologic factors [ 28 , 33 , 37 , 38 , 39 ], and other factors. Many methods have been employed to use these bases for catchment classification, including regression-based methods [ 3 , 8 , 33 , 40 ], clustering [ 5 , 6 , 8 , 16 , 17 , 19 , 21 , 33 , 34 , 35 , 36 ], flow duration curve analysis [ 12 , 13 , 41 ], principal component analysis [ 3 , 6 , 18 , 29 ], and process-based modeling [ 11 ], among others. Applications of the concepts of community structure within the context of complex networks for catchment classification are also starting to emerge [ 42 , 43 ].…”