Effect of drainage area on hypsometry from an analysis of small-scale drainage basins in the Siwalik Hills (Central Nepal)

Hypsometry of drainage basins (area-elevation analysis) has generally been used to infer the stage of geomorphic development and to study the influenc e of varying forcing factors (i.e. tectonics, climate, lithology) on topogr aphy. However, the scale dependence of hypsometry has generally been neglec ted. In order to assess the scale dependence of hypsometry, this study focu ses on the sensitivity of hypsometry to different Digital Elevation Model ( DEM) resolutions and on the influence of drainage area. Hypsometry inferred from different DEMs is shown to be robust against variations of their reso lution. However, hypsometry appears to be dependent on drainage area. We pr opose that this scale dependence may reflect the varying importance of rive r and hillslope processes with basin area. Copyright (C) 1999 John Wiley & Sons, Ltd.