Abstract Indices measuring drainage basin shape are of great significance because they not only measure forms (shape) of basins but provide quantitative information upon basin shape that controls the flow hydrograph of the channel. We reviewed different measures of basin shape and found the Elongation ratio (E), Form factor (F), Lemniscate ratio (k), and Shape factor (S) can not detect differences between shapes of a very long narrow basin without indenture in perimeter and a highly indented star-fish-shaped?basin. Limitation of these indices was felt in the context of indenture studies of shapes. The present study adopted the Indenture index (I) to have a detailed insight into the indented plan view of drainage-basin outline. We also added Circularity index (Ci), a refined form of Compactness coefficient (Cc), which bears the traits of an ideal index and is a good tool for measuring basin shapes. Eight indices were applied for testing the hydrologic implications of the shape of a drainage basin. Indenture index (I) could effectively be employed for measuring indented basin-shapes (1?=?no indenture, a higher value indicates indented shape) and assessing the impact of basin shape on the Flood Inducing Capacity (FCI) of a basin (R2?=?0.208). The present study will not only bridge the gaps in the existing hydro-geomorphic research but also has some policy implications in the context of basin hydrology. The use of simulation and artificial intelligence (AI) for overcoming the limitation of data size may open better avenues in the directions of basin-shape research and its hydrologic implications.
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