Stream power

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

Response of Sheet Erosion to the Characteristics of Physical Soil Crusts for Loessial Soils

Abstract: The influences and quantifications of soil crust traits on the infiltration, hydrodynamic of runoff, and erosion rate of sheet erosion under the combined effects of raindrop impact and sheet flow scouring need further study. Loessial soil from the Loess Plateau was tested to produce different antecedent crusts under simulated rainfall intensities (0.5, 1.0, 1.5, 2.0, and 2.5 mm/min, typical storm intensity in the area), and then the effects of antecedent crusts on sheet erosion processes were quantified at a rainfall intensity of 1.5 mm/min. The results showed that the bulk density and hardness of antecedent crusts were higher than those of soil. Particle sizes of crusts were smaller than those of soil at light rain intensity but larger under heavy rain intensity. The bulk density, hardness, and particle size D 50 of the antecedent crust were all positively correlated with rainfall intensity, being well described by linear equations ( R 2 > 0.87), while the thickness was negatively linearly correlated with rainfall intensity ( R 2 = 0.88). Although the existence of antecedent crusts could decrease the infiltration and increase the runoff, resulting in the high flow velocity and stream power, antecedent crusts could still effectively reduce sheet erosion. The reductions in the average infiltration rate and average erosion rate and the increases of average flow velocity and stream power all increased with the increment of bulk density of antecedent crust. Relationships could be all well described by linear positive correlations ( R 2 > 0.79). When the bulk density of crust was enhanced by 27∼29%, the flow velocity and stream power could be increased by 8∼29% and 15∼70%, and the sheet erosion could be reduced by 61∼73%. The existence of crust could effectively reduce sheet erosion. These results could help understand the mechanism of the erosion process in the presence of physical crusts.

Two-dimensional modelling of stream channel dynamics in the Naches River, Washington

Abstract: The detailed, spatially explicit mapping of fluvial landscapes is fundamental to river science. However, data models capable of incorporating system variability are largely lacking from scientific literature. This research examines a reach of the Naches River, a wandering gravel-bed river located in central Washington State. Stream gauge records are used to calculate flow probabilities, and River2D, a two-dimensional hydrodynamic model, is combined with a LiDAR data set to model flows and compute spatially distributed process variables (e.g. shear stress and stream power). In a geographic information system, fuzzy logic is used to model flow transition zones. The resulting data model, through its incorporation of system spatial and temporal variability, provides an alternative to the static classifications traditionally employed in fluvial research.

Conditions to Preserve the Sedimentary Record of Channel Planforms in Temperate Rivers of the Northern Hemisphere

Abstract: We aim to identify conditions that influence the preservation of a complete record of channel planforms in the topmost layer of floodplains, prior to the maintenance in the rock record. We have tested a hypothesis that a successive decrease of stream power and channel belt width are necessary to preserve the record of channel planforms in the topmost floodplain layer over 10−3 to 10−4-year time scales. A literature review was conducted for rivers of the temperate zone of the Northern Hemisphere. Stream power, valley, and channel belt widths, paleodischarges, sediment grain-size, and age of paleochannels were used to identify four groups of rivers with preservation potential ranging from tens of thousands years to annual time scales. The decrease in stream power followed by sustained low stream power, and successive decrease of channel belt width were identified in rivers preserving a 10−3 to 10−4-year record of channel planforms. River valleys with the record of at least two generations of paleochannels, and valley width/channel belt width ratios between 6 and 12, potentially preserve fluvial records over 10−3 to 10−4-year time scales. We analyzed unusually well-preserved records of channel planforms from the Obra and Sió Rivers (central Europe). A determination of trends in changes of stream power and channel belt widths based on an extensive set of geophysical, geological data, and sediment dating from earlier studies, confirmed the tested hypothesis. The proposed framework can be extended by fluvial records preserved by large, and coastal rivers, with the potential to include ancient fluvial records.

Downstream Grain-Size Variation to Interpret River-Channel Process-form in the Middle-Lower Yangtze River, China

Abstract: In 2000 and 2003, five-hundred and twenty (520) riverbed sediment samples were taken from the middle-lower Yangtze trunk channel to examine the river hydromorphological nature. Analytical result shows that the riverbeds mostly consist of mostly medium to coarse sands, but silty fine sand near the river coast. The result further indicates 12 zones (I–XII), identified as alternated coarse- fine-grained riverbed, except zone I – III. Grain-size associated hydrological parameters indicates higher values in the Jingjiang Reaches (Yichang to Chenglingji) (unit stream power: 5–18 N/ms, boundary shear stress: 14 N/m2 and mean flow velocity: 2–3.2 m/s), while the values obtained from Chenglingji downstream are considerable lower (<5 N/ms, 1–4 N/m2 and <0.7–1.5 m/s). These, when comparing with on-site measured ADP flow column velocity, revealed the erosive riverbed sediment transport in the Jingjiang Reaches, and the accumulative riverbed transport downstream, especially from Wuhan to the river coast. Hydrological parameters together with grain size distribution saw a coarsening riverbed in the Jingjiang river course, largely due to damming since the last half-century. This corroborates the weakening sediment zonation in the Jingjiang Reaches, which we believe will further extend downstream to the river coast in the coming decades.

Sediment rating curve for the Ganges river

Abstract: In this study, a sediment rating curve for the Ganges river at Hardinge bridge gauge station has been developed by establishing power relations between sediment transport as dependent variable and discharge and unit stream power as independent variables separately. The unit stream power used as independent variable gives an improved curve. The sediment rating curve improves significantly when it is developed by partitioning the data into rising, flood and falling limbs.