scholarly journals Informational Entropy Approach for Rating Curve Assessment in Rough and Smooth Irrigation Ditch

2019 ◽  
Author(s):  
Greco Michele
Keyword(s):  
Informational Entropy ◽  
Rating Curve ◽  
Irrigation Ditch

Regionalization of sediment rating curve for sediment yield prediction in ungauged catchments

2013 ◽  
Vol 46 (1) ◽  
pp. 26-38 ◽  
Author(s):  
Sokchhay Heng ◽  
Tadashi Suetsugi
Keyword(s):  
Sediment Yield ◽  
Model Performance ◽  
Data Uncertainty ◽  
Spatial Proximity ◽  
Yield Prediction ◽  
Rating Curve ◽  
Ungauged Catchments ◽  
Probability Curve ◽  
Sediment Rating Curve ◽  
Almost All

The main objective of this research is to regionalize the sediment rating curve (SRC) for subsequent sediment yield prediction in ungauged catchments (UCs) in the Lower Mekong Basin. Firstly, a power function-based SRC was fitted for 17 catchments located in different parts of the basin. According to physical characteristics of the fitted SRCs, the sediment amount observed at the catchment outlets is mainly transported by several events. This also indicates that clockwise hysteretic phenomenon of sediment transport is rather important in this basin. Secondly, after discarding two outlier catchments due to data uncertainty, the remaining 15 catchments were accounted for the assessment of model performance in UCs by means of jack-knife procedure. The model regionalization was conducted using spatial proximity approach. As a result of comparative study, the spatial proximity approach based on single donor catchment provides a better regionalization solution than the one based on multiple donor catchments. By considering the ideal alternative, a satisfactory result was obtained in almost all the modeled catchments. Finally, a regional model which is a combination of the 15 locally fitted SRCs was established for use in the basin. The model users can check the probability that the prediction results are satisfactory using the designed probability curve.

Efficiency of crude oil markets: Evidences from informational entropy analysis

Energy Policy ◽  
2012 ◽  
Vol 41 ◽  
pp. 365-373 ◽  
Author(s):  
Alejandro Ortiz-Cruz ◽  
Eduardo Rodriguez ◽  
Carlos Ibarra-Valdez ◽  
Jose Alvarez-Ramirez
Keyword(s):  
Crude Oil ◽  
Entropy Analysis ◽  
Informational Entropy ◽  
Oil Markets

scholarly journals Hydroclimatic control on suspended sediment dynamics of a regulated Alpine catchment: a conceptual approach

2018 ◽  
Vol 22 (6) ◽  
pp. 3421-3434 ◽  
Author(s):  
Anna Costa ◽  
Daniela Anghileri ◽  
Peter Molnar
Keyword(s):  
Suspended Sediment ◽  
Sediment Concentration ◽  
Sediment Dynamics ◽  
Time Lags ◽  
Rating Curve ◽  
Conceptual Approach ◽  
Ice Melt ◽  
Alpine Catchments ◽  
Erosive Rainfall ◽  
Hydroclimatic Variables

Abstract. We analyse the control of hydroclimatic factors on suspended sediment concentration (SSC) in Alpine catchments by differentiating among the potential contributions of erosion and suspended sediment transport driven by erosive rainfall, defined as liquid precipitation over snow-free surfaces, ice melt from glacierized areas, and snowmelt on hillslopes. We account for the potential impact of hydropower by intercepting sediment fluxes originated in areas diverted to hydropower reservoirs, and by considering the contribution of hydropower releases to SSC. We obtain the hydroclimatic variables from daily gridded datasets of precipitation and temperature, implementing a degree-day model to simulate spatially distributed snow accumulation and snow–ice melt. We estimate hydropower releases by a conceptual approach with a unique virtual reservoir regulated on the basis of a target-volume function, representing normal reservoir operating conditions throughout a hydrological year. An Iterative Input Selection algorithm is used to identify the variables with the highest predictive power for SSC, their explained variance, and characteristic time lags. On this basis, we develop a hydroclimatic multivariate rating curve (HMRC) which accounts for the contributions of the most relevant hydroclimatic input variables mentioned above. We calibrate the HMRC with a gradient-based nonlinear optimization method and we compare its performance with a traditional discharge-based rating curve. We apply the approach in the upper Rhône Basin, a large Swiss Alpine catchment heavily regulated by hydropower. Our results show that the three hydroclimatic processes – erosive rainfall, ice melt, and snowmelt – are significant predictors of mean daily SSC, while hydropower release does not have a significant explanatory power for SSC. The characteristic time lags of the hydroclimatic variables correspond to the typical flow concentration times of the basin. Despite not including discharge, the HMRC performs better than the traditional rating curve in reproducing SSC seasonality, especially during validation at the daily scale. While erosive rainfall determines the daily variability of SSC and extremes, ice melt generates the highest SSC per unit of runoff and represents the largest contribution to total suspended sediment yield. Finally, we show that the HMRC is capable of simulating climate-driven changes in fine sediment dynamics in Alpine catchments. In fact, HMRC can reproduce the changes in SSC in the past 40 years in the Rhône Basin connected to air temperature rise, even though the simulated changes are more gradual than those observed. The approach presented in this paper, based on the analysis of the hydroclimatic control of suspended sediment concentration, allows the exploration of climate-driven changes in fine sediment dynamics in Alpine catchments. The approach can be applied to any Alpine catchment with a pluvio-glacio-nival hydrological regime and adequate hydroclimatic datasets.

Application of a flow-measurement structure for sediment-laden streams

2009 ◽  
Vol 36 (9) ◽  
pp. 1539-1543
Author(s):  
Mustafa Göğüş ◽  
A. Cüneyt Gerek ◽  
A. Burcu Altan-Sakarya
Keyword(s):  
Water Level ◽  
Flow Measurement ◽  
Sediment Load ◽  
Real Data ◽  
Flow Depth ◽  
Rating Curve ◽  
Natural Streams ◽  
The Relationship ◽  
High Sediment ◽  
Single Relation

Generally, measurement of flow in natural streams is accomplished by measuring the flow depth. Hence, the relationship between the water level and discharge should be obtained in advance. However, in streams with high sediment load, the bottom level may change due to sediment deposition, preventing the single relation between water level and discharge. This paper summarizes the application of a flow-measurement structure for sediment-laden streams. The proposed structure is designed and built in Turkey and has been under operation since 1998 without any sedimentation problem. The agreement between the real data obtained from the structure and the theoretical rating curve is quite reasonable.

Water balance in the Dutch river Rhine and rating curve uncertainty

2020 ◽  
pp. 2171-2178
Author(s):  
J.J. Twijnstra ◽  
M.R.A. Gensen ◽  
J.J. Warmink ◽  
S.J.M.H. Hulscher ◽  
F. Huthoff ◽  
...  
Keyword(s):  
Water Balance ◽  
River Rhine ◽  
Rating Curve

scholarly journals Sectorial perturbation of vortex beams: Shannon entropy, orbital angular momentum and topological charge

2019 ◽  
Vol 43 (5) ◽  
pp. 723-734 ◽  
Author(s):  
A.V. Volyar ◽  
M.V. Bretsko ◽  
Ya.E. Akimova ◽  
Yu.A. Egorov ◽  
V.V. Milyukov
Keyword(s):  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Shannon Entropy ◽  
Topological Charge ◽  
External Perturbation ◽  
Informational Entropy ◽  
Large Perturbation ◽  
Wide Range ◽  
Vortex Beams ◽  
Computing Measuring

Transformations of the vortex beams structure subjected to sectorial perturbation were theoretically and experimentally studied. The analysis was based on computing (measuring) the vortex spectrum that enables us to find the orbital angular momentum (OAM) and Shannon entropy (informational entropy). We have revealed that, in the general case, the number of vortices caused by an external perturbation is not related to the topological charge. For arbitrary perturbation, the topological charge remains equal to the initial topological charge of the unperturbed vortex beam. Growth of the vortex number induced by perturbations is associated with the optical uncertainty principle between the sectorial angle and the OAM. The computer simulation has shown that OAM does not depend on the number of vortices induced by perturbations. Moreover, two maxima are formed both in the positive and negative regions of the vortex spectrum. As a result, the OAM does not practically change in a wide range of perturbation angles from 0 to 90 °. However, at large perturbation angles, when the energy is almost equally redistributed between the vortex modes with opposite signs of the topological charge, the OAM rapidly decreases. At the same time, the Shannon entropy monotonically increases with growing perturbation angle. This is due to the fact that the entropy depends only on the number of vortex states caused by external perturbations.

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