Stream power

About: Stream power is a research topic. Over the lifetime, 1135 publications have been published within this topic receiving 51324 citations.

River dynamics and existing stability condition of the Manahara River , Kathmandu basin, Central Nepal Himalaya

Abstract: Five representative segments of the river were surveyed in detail for evaluating its dynamics and stability condition. The first(downstream) to the fifth (upstream) segments are classified as ‘F4’, ‘C4’, ‘C4’, ‘B4’ and ‘B4’ streams characterised by gravellysubstrates. All these streams are competent enough to transport their bed material (d90) as shown by the exceeding dimensionlessshear stress over critical dimensionless shear stress of the river segments. The existing depth and slope of the river is far enoughto carry d90 of the substrate grain size. Stream power of segments 1 to 5 are respectively, 622.6, 79.0, 146.6, 354.6 and 15617.0KN/s. The ‘B4’ streams show greater stream power, i.e., transport capacity compared to ‘F4’ followed by ‘C4’ streams. Therefore,the ‘B4 streams (3rd and 4th order streams) are potential to degradation, and the ‘C4’ and ‘F4’ (both 5th order) streams arepotential to aggradation depending on river morphology and dynamics. Meander geometry of the Manahara River exhibit deviationof variables (meander wavelength vs channel width, and meander belt width vs channel width) from the stability, suggestingexistence of instability to some extent in the river. DOI: http://dx.doi.org/10.3126/bdg.v14i0.5430 Bulletin of the Department of Geology Vol.14 2011, pp.1-8

Comparative study on different sediment transport capacity based on dimensionless flow intensity index

Abstract: Sediment transport plays a vital role in the development of soil erosion process models. The primary purpose of this study is to establish new sediment transport capacity formulas and evaluate their applicability to sediment. In this study, we collected three different soil types from Loess Plateau. Simulated sediment transport experiments were carried out in indoor flumes with energy gradients ranging from 6.9 to 20.8% and unit flow discharge rates ranging from 0.00014 to 0.00111 m2 s−1. We found an exponential relationship between sediment transport capacity, energy gradients, and unit flow discharge rates. The sediment transport capacity increased with increasing energy gradient and unit flow discharge, and the unit flow discharge had a more significant influence on sediment transport capacity compared with energy gradient. We used each composite force predictor and measured the sediment transport capacity according to the nondimensional principle, and the resulting data corresponded to different soils distributed in zones, as sediment transport capacity is controlled by a critical starting condition. After including soil clay particle content and volume sediment content in our formula, we were able to derive an accurate equation for calculating sediment transport. Among the dimensionless composite force predictors, the dimensionless effective stream power was the most reliable predictor. The sediment transport capacity and effective stream power were related exponentially (R2 = 0.953).

High bedload transport rates in relation to stream power Wadi Mikeimin, Sinai

Abstract: Summary A reconstruction of a low-frequency high-magnitude flood event, which occurred in January 1971 in the watershed of Wadi Mikeimin in the arid southeastern Sinai mountains, enabled the evaluation of bedload transport rates in relation to flow characteristics. Unit transport rates between 20 and 100 kg/ms, i.e. at least one order of magnitude higher than nearly all data previously reported, are compatible with data on other rivers. The proportionality of bedload transport rate to unit stream power in excess of that necessary for initial motion, raised to the power of 3/2, has been validated for these very high transport rates, which approach debris flows in character.

Modeling glacial and fluvial landform evolution at large scales using a stream-power approach

Abstract: . Modeling glacial landform evolution is more challenging than modeling fluvial landform evolution. While several numerical models of large-scale fluvial erosion are available, there are only a few models of glacial erosion, and their application over long time spans requires a high numerical effort. In this paper, a simple formulation of glacial erosion which is similar to the fluvial stream-power model is presented. The model reproduces the occurrence of overdeepenings, hanging valleys, and steps at confluences at least qualitatively. Beyond this, it allows for a seamless coupling to fluvial erosion and sediment transport. The recently published direct numerical scheme for fluvial erosion and sediment transport can be applied to the entire domain, where the numerical effort is only moderately higher than for a purely fluvial system. Simulations over several million years on lattices of several million nodes can be performed on standard PCs. An open-source implementation is freely available as a part of the landform evolution model OpenLEM.

Flood hazard evaluation in small catchments based on quantitative geomorphology and GIS modeling: The case of Diakoniaris torrent (W. Peloponnese, Greece)

Abstract: This study deals with the evaluation of flash flood hazard in the ungauged Diakoniaris torrent drainage basin which is a fifth order stream located in northwestern Peloponnese. Diakoniaris drains an area of 27.83 km2 and discharges into the Gulf of Patras. Its lower reaches flow through the city of Patras and has suffered from intense human interferences due to increased urbanization during the last decades. For the purposes of the study the quantitative geomorphological characteristics of the basin were estimated and studied focusing on the investigation of the hierarchical drainage by stream order. The longitudinal profiles as well as the stream power diagrams of the main stream channel and its major tributaries were constructed and analyzed. A routing model based on runoff travel time was created within GIS environment in order to estimate the discharge at the outlet of the basin for an assumed extreme rainfall event.