The sediment load of Indian rivers - an update

摘要: This paper summarizes recent information collected on sediment transport in Indian rivers. It reveals the major contribution which rivers make to total amount of delivered ocean at a global scale, but also highlights large temporal and spatial variability riverine sub-continent. is evident not only quantity transported size mineralogical characteristics loads. INTRODUCTION The present estimate discharge 15-16 x 101 year (Walling & Webb, 1983) perhaps an underestimated value due undetermined values for several minor catchments (Milliman&Meybeck, 1995). Nevertheless, it now well recognized that Pacific Oceanic islands South Southeast Asia constitute single geographic region contributes nearly 80% budget. Over years, considerable data have been concerning For example, Abbas Subramanian (1984) estimated load Ganges Farraka Barrage be 1235 t km" year", 8 times world average erosion rate (1501 year") calculated by Milliman Meade (1983). To improve our understanding processes Asia, there need examine recently information. RECENT DATA A has shown Ramanathan et al. (1994) River Cauvery are linearly related when plotted logarithmic axes (Fig. 1). Measurements seven selected locations system over period four water years (1975/76-1978/79) reveal change systematically with (Ramanathan al., 1994). However, these show relationship 2). believed reflect influence selective mobilization fine (Ramanathan, 1993) river 3). Comparison rates sedimentation Mahanadi 4), however, suggests does lead balance between processes, indicates dominance deposition within this (Chakrapani Subramanian, 1993).