scholarly journals A New Empirical Approach to Calculating Flood Frequency in Ungauged Catchments: A Case Study of the Upper Vistula Basin, Poland

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 601 ◽  
Author(s):  
Dariusz Młyński ◽  
Andrzej Wałęga ◽  
Tomasz Stachura ◽  
Grzegorz Kaczor
Keyword(s):  
Empirical Model ◽  
Catchment Area ◽  
Flood Frequency ◽  
Ungauged Catchments ◽  
Volume Determination ◽  
Statistical Verification ◽  
Observation Series ◽  
Data Estimation

The aim of the work was to develop a new empirical model for calculating the peak annual flows of a given frequency of occurrence (QT) in the ungauged catchments of the upper Vistula basin in Poland. The approach to the regionalization of the catchment and the selection of the optimal form of the empirical model are indicated as a novelty of the proposed research. The research was carried out on the basis of observation series of peak annual flows (Qmax) for 41 catchments. The analysis was performed in the following steps: statistical verification of data; estimation of Qmax flows using kernel density estimation; determination of physiographic and meteorological characteristics affecting the Qmax flow volume; determination of the value of dimensionless quantiles for QT flow calculation in the upper Vistula basin; verification of the determined correlation for the calculation of QT flows in the upper Vistula basin. Based on the research we conducted, we found that the following factors have the greatest impact on the formation of flood flows in the upper Vistula basin: the size of catchment area; the height difference in the catchment area; the density of the river network; the soil imperviousness index; and the volume of normal annual precipitation. The verification procedure that we performed made it possible to conclude that the developed empirical model functions correctly.

scholarly journals Possibility of Using Selected Rainfall-Runoff Models for Determining the Design Hydrograph in Mountainous Catchments: A Case Study in Poland

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1450 ◽  
Author(s):  
Dariusz Młyński ◽  
Andrzej Wałęga ◽  
Leszek Książek ◽  
Jacek Florek ◽  
Andrea Petroselli
Keyword(s):  
Catchment Area ◽  
Peak Flow ◽  
Rainfall Runoff ◽  
Peak Flows ◽  
Mountainous Catchment ◽  
Mountainous Catchments ◽  
Relative Errors ◽  
Runoff Hydrographs

The aim of the study was to analyze the possibility of using selected rainfall-runoff models to determine the design hydrograph and the related peak flow in a mountainous catchment. The basis for the study was the observed series of hydrometeorological data for the Grajcarek catchment area (Poland) for the years 1981–2014. The analysis was carried out in the following stages: verification of hydrometeorological data; determination of the design rainfall; and determination of runoff hydrographs with the following rainfall-runoff models: Snyder, NRCS-UH, and EBA4SUB. The conducted research allowed the conclusion that the EBA4SUB model may be an alternative to other models in determining the design hydrograph in ungauged mountainous catchments. This is evidenced by the lower values of relative errors in the estimation of peak flows with an assumed frequency for the EBA4SUB model, as compared to Snyder and NRCS-UH.

scholarly journals Analysis of Problems Related to the Calculation of Flood Frequency Using Rainfall-Runoff Models: A Case Study in Poland

2020 ◽  
Vol 12 (17) ◽  
pp. 7187
Author(s):  
Dariusz Młyński
Keyword(s):  
Sensitivity Analysis ◽  
Return Period ◽  
Maximum Flow ◽  
High Sensitivity ◽  
Flood Frequency ◽  
Rainfall Runoff ◽  
Model Quality ◽  
Retention Capacity

This work aimed to quantify how the different parameters of the Snyder model influence the errors in design flows. The study was conducted for the Kamienica Nowojowska catchment (Poland). The analysis was carried out according to the following stages: determination of design precipitation, determination of design hyetograph, sensitivity analysis of the Snyder model, and quality assessment of the Snyder model. Based on the conducted research, it was found that the Snyder model did not show high sensitivity to the assumed precipitation distribution. The parameters depending on the retention capacity of the catchment had much greater impact on the obtained flow values. The verification of the model quality showed a significant disproportion in the calculated maximum flow values with the assumed return period.

scholarly journals Determination of Watershed Characteristics and Curve Number (CN) for Ponnaniyaru Dam Catchment Area

2018 ◽  
Vol 7 (3.12) ◽  
pp. 558
Author(s):  
Selvakumar R ◽  
Nasir N ◽  
Suribabu C R
Keyword(s):  
Catchment Area ◽  
Curve Number ◽  
Drainage Density ◽  
Significant Parameter ◽  
Present Case Study ◽  
Scs Cn ◽  
Hydrologic Conditions ◽  
Selection Of

In SCS-CN method, curve number is significant parameter in estimating runoff from the catchment of the reservoir or inflow to the reservoir. As this curve number is function of several parameters like hydrological soil group, LULC, land treatment, hydrologic conditions and AMC, the selection of CN for prediction of inflow to the lake or reservoir is considered as a crucial in the hydrological studies. LULC, micro-watershed, drainage density, and catchment slope are obtained using spatial analysis and also SCS Curve Number value for Ponnaniyaru dam catchment area is derived from the LULC data. Further, CN value is evaluated from actual rainfall data and runoff volume collected at the reservoir. The study reveals the significant variation of CN value among each event. The present case study highlights the sensitiveness of CN value in the computation of runoff from the watershed. Keywords: Curve number, LULC, AMC, drainage density. 

scholarly journals Accessibility of Transit Stops with Multiple Feeder Modes: Walking and Private-Bike Cycling

2021 ◽  
Vol 13 (6) ◽  
pp. 3522
Author(s):  
Mingzhu Song ◽  
Yi Zhang ◽  
Meng Li ◽  
Yi Zhang
Keyword(s):  
Catchment Area ◽  
Critical Index ◽  
Transit Planning ◽  
City Managers ◽  
Model Combining ◽  
Last Mile ◽  
Level Model ◽  
In Transit

The accessibility of transit stops (ATS) is a critical index for the evaluation of transit service, focusing on the first/last mile portions of transit trips. It is significantly affected by feeder modes, such as walking and cycling. Comparison of the application of different modes has been addressed in previous research, thus there is mostly only one feeder mode considered in this case study. This study has proposed a model for ATS with multiple feeder modes (ATSMFM), capable of integrating multiple feeder modes and considering the heterogeneity of travellers from the perspective of city managers. It is a bi-level model, combining cumulative and utility-based approaches. The final form of ATSMFM is developed referring to the cumulative approach, while the determination of the catchment area is utility-based. A numerical experiment has been conducted to demonstrate the necessity and applicability of ATSMFM. The results show that the ATS with a single feeder mode, such as cycling or walking, underestimates the catchment area of nearly one-third or two-thirds of travellers. As for ATSMFM, this proposed approach can automatically select the feeder mode from alternatives according to traveller attributes, thus removing the limitation of a single feeder mode, and is suitable for calculating ATS in the complex environment with multiple feeder modes. Besides, the ATSMFM model can support city managers with different emphases in transit planning via flexibly setting the threshold.

scholarly journals Determination of Empirical Formula Model of Soil Vibration Acceleration of Denpasar Area

2018 ◽  
Vol 19 (1) ◽  
pp. 23
Author(s):  
Dwi Karyadi Priyanto ◽  
K.N. Suarbawa ◽  
Ardhianto Septiadhi
Keyword(s):  
Empirical Model ◽  
Empirical Formula ◽  
Peak Ground Acceleration ◽  
Spreading Coefficient ◽  
Geometrical Spreading ◽  
Vibration Acceleration ◽  
Ground Acceleration ◽  
Statistical Verification ◽  
Positive Linear Correlation

In this research, we have determined the model of empirical formula of Peak Ground Acceleration (PGA) based on general formula of Lin and Wu using 62 observational PGA data which corresponds to earthquake parameter data of Bali and its surroundings for year 2008-2013. Based on the regression analysis, the geometrical spreading coefficient is a = -2.019, the magnitude coefficient b = 0.894, the empirical model formula constant c = 0.551, and the empirical model of PGA model for Denpasar is. The results of statistical verification yielded a strong positive linear correlation of 0.853 with the residual error of 0.035.

scholarly journals An elusive search for regional flood frequency estimates in the River Nile basin

2012 ◽  
Vol 9 (3) ◽  
pp. 2675-2715
Author(s):  
P. Nyeko-Ogiramoi ◽  
P. Willems ◽  
F. M. Mutua ◽  
S. A. Moges
Keyword(s):  
Catchment Area ◽  
Peak Flow ◽  
Regional Growth ◽  
Growth Curves ◽  
Flood Frequency ◽  
River Nile ◽  
Nile Basin ◽  
Ungauged Catchments ◽  
Hydrological Characteristics ◽  
Record Length

Abstract. Estimation of peak flow quantiles in ungauged catchments is a challenge often faced by water professionals in many parts of the world. Approaches to address such problem exist but widely used technique such as flood frequency regionalization is often not subjected to performance evaluation. In this study we used the jack-knifing principle to assess the performance of the flood frequency regionalization in the complex and data scarce River Nile basin by examining the error (regionalization error) between locally and regionally estimated peak flow quantiles for different return periods (QT). Agglomerative hierarchical clustering based algorithms were used to search for regions with similar hydrological characteristics taking into account the huge catchment area and strong climatic differences across the area. Hydrological data sets employed were from 180 gauged catchments and several physical characteristics in order to regionalize 365 identified catchments. The GEV distribution, selected using L-moment based approach, was used to construct regional growth curves from which peak flow growth factors (QT/MAF) could be derived and mapped through interpolation. Inside each region, variations in at-site flood frequency distribution were modeled by regression of the mean annual maximum peak flow (MAF) versus catchment area. The results show that the performance of the regionalization is heavily dependent on the historical flow record length and the similarity of the hydrological characteristics inside the regions. The flood frequency regionalization of the River Nile basin can be improved if sufficient flow data of longer record length × 40 become available.

A novel method for the determination of linting propensity of paper

TAPPI Journal ◽  
2012 ◽  
Vol 11 (10) ◽  
pp. 9-17
Author(s):  
ALESSANDRA GERLI ◽  
LEENDERT C. EIGENBROOD
Keyword(s):  
Ash Content ◽  
The Novel ◽  
Offset Printing ◽  
Excellent Correlation ◽  
End Conditions ◽  
Bottom Side ◽  
Novel Method ◽  
Total Fraction

A novel method was developed for the determination of linting propensity of paper based on printing with an IGT printability tester and image analysis of the printed strips. On average, the total fraction of the surface removed as lint during printing is 0.01%-0.1%. This value is lower than those reported in most laboratory printing tests, and more representative of commercial offset printing applications. Newsprint paper produced on a roll/blade former machine was evaluated for linting propensity using the novel method and also printed on a commercial coldset offset press. Laboratory and commercial printing results matched well, showing that linting was higher for the bottom side of paper than for the top side, and that linting could be reduced on both sides by application of a dry-strength additive. In a second case study, varying wet-end conditions were used on a hybrid former machine to produce four paper reels, with the goal of matching the low linting propensity of the paper produced on a machine with gap former configuration. We found that the retention program, by improving fiber fines retention, substantially reduced the linting propensity of the paper produced on the hybrid former machine. The papers were also printed on a commercial coldset offset press. An excellent correlation was found between the total lint area removed from the bottom side of the paper samples during laboratory printing and lint collected on halftone areas of the first upper printing unit after 45000 copies. Finally, the method was applied to determine the linting propensity of highly filled supercalendered paper produced on a hybrid former machine. In this case, the linting propensity of the bottom side of paper correlated with its ash content.

Phosphino-Triazole Ligands for Palladium-Catalysed Cross-Coupling

2018 ◽  
Author(s):  
Yiming Zhao ◽  
Huy van Nguyen ◽  
Louise Male ◽  
Philip Craven ◽  
Benjamin R. Buckley ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Cross Coupling ◽  
Product Formation ◽  
Coupling Reactions ◽  
Volume Determination ◽  
Online Tool ◽  
Triazole Derivatives ◽  
Cross Coupling Reactions ◽  
Modelling Approaches

<div>Twelve 1,5-disubtituted and fourteen 5-substituted 1,2,3-triazole derivatives bearing diaryl or dialkyl phosphines at the 5-position were synthesised and used as ligands for palladium-catalysed Suzuki-Miyaura cross-coupling reactions. Bulky substrates were tested, and lead-like product formation was demonstrated. The online tool SambVca 2.0 was used to assess steric parameters of ligands and preliminary buried volume determination using XRD obtained data in a small number of cases proved to be informative. Two modelling approaches were compared for the determination of</div><div>the buried volume of ligands where XRD data was not available. An approach with imposed steric restrictions was found to be superior in leading to buried volume determinations that closely correlate with observed reaction conversions. The online tool LLAMA was used to determine lead-likeness of potential Suzuki-Miyaura cross-coupling products, from which ten of the most lead-like were successfully synthesised. Thus, confirming these readily accessible triazole-containing phosphines as highly suitable ligands for reaction screening and optimisation in drug discovery campaigns.</div>

The Calculation of Turbulent Diffusion Coefficients in Aquatic Ecosystems

2019 ◽  
Vol 70 (11) ◽  
pp. 3903-3907
Author(s):  
Galina Marusic ◽  
Valeriu Panaitescu
Keyword(s):  
Transport Equation ◽  
Turbulent Diffusion ◽  
Diffusion Coefficients ◽  
Aquatic Ecosystems ◽  
Specific Area ◽  
Left Bank ◽  
The Right ◽  
Prut River

The paper deals with the issues related to the pollution of aquatic ecosystems. The influence of turbulence on the transport and dispersion of pollutants in the mentioned systems, as well as the calculation of the turbulent diffusion coefficients are studied. A case study on the determination of turbulent diffusion coefficients for some sectors of the Prut River is presented. A new method is proposed for the determination of the turbulent diffusion coefficients in the pollutant transport equation for specific sectors of a river, according to the associated number of P�clet, calculated for each specific area: the left bank, the right bank and the middle of the river.

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