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1

Flood Frequency Analysis and Hydraulic Design of Bridge at Mashan on River Kunhar

Riaz Khuram, Aslam Hafiz Muhammad Shahzad, Yaseen Muhammad Waseem, Ahmad Hafiz Haseeb, Khoshkonesh Alireza, Noshin Sadaf

Archives of Hydro-Engineering and Environmental Mechanics

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2022

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Vol. 69, nr 1

1--12

EN

Kunhar River hydrology and hydraulic design of a bridge on this river are being studied using HEC-Geo-RAS and Hydrologic Engineering Centers River Analysis System (HEC-RAS). The river flows in the northern part of Pakistan and is 170 km long. On both sides of the river, there are residential settlements. The river hydraulics is studied by using 30-metre remotely sensed shuttle radar topographic mission - digital elevation model (SRTM DEM) and Arc Map. 32 cross-sections are imported from Geographic Information System (GIS) to HEC-RAS. On historical peak flow results, the extreme value frequency distribution is applied, and a flood is determined for a 100-year return period, with a discharge estimated as 2223 cubic metres. Three steady flow profiles are adopted for HEC-RAS, the first is for the maximum historical peak data, the second is for the 100-year return period, and the third profile is for the latter 100-year period with a safety factor of 1.28. With remote sensing-based assessments, the proposed location for a bridge is determined and then verified with a field survey which was physically conducted. The maximum water height estimated in the river is about 4.26 m. This bridge will facilitate about 50 thousand population of Masahan and its surroundings. It will create a shortest link between Khyber Pakhtunkhwa and Azad Kashmir and thus will enhance tourism and trade activities.

2

Extreme wind waves in the Black Sea

Divinsky Boris V., Fomin Vladimir V., Kosyan Ruben D., Ratner Yuri D.

Oceanologia

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2020

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No. 62 (1)

23--30

EN

Results of the analysis of a long-term data set, including fields of significant wave heights of the surface wave components, and mixed (total) wave field in the Black Sea are presented. The data set was collected on the basis of retrospective calculations using the MIKE 21 SW spectral wave model with the atmospheric forcing based on the ERA-Interim data in the period from 1979 to 2017. A criterion is used to isolate the swell waves from the initial wave data set that takes into account the wave age. We used the experimental data to develop a regression relationship showing that the maximum possible wave height can exceed the significant wave height approximately one and a half times. Analysis of the spatial distribution of wave heights in the Black Sea suggests that a possibility exists that significant wave height of storm waves can be as high as ∼12 m. This result indicates that the actual heights of maximum waves in the Black Sea can reach 18-19 m. Three regions are distinguished on the basis of the wave potential. The times of manifestation of extreme situations in these regions are different: in the southwestern part of the sea, extreme storm situations occur, as a rule, in December-January; in the region south of the Crimea Peninsula this happens in February; in the northeastern part of the sea they occur in November. It was also found that the south-southeastern and eastern parts of the sea are most affected by swell.

3

Relationship between selected percentiles and return periods of extreme events

Camufo Dario, Becherini Francesca, della Valle Antonio

Acta Geophysica

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2020

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Vol. 68, no. 4

1201--1211

EN

This paper investigates the relationship between selected percentiles, return periods and the concepts of rare and extreme events in climate and hydrological series, considering both regular and irregular datasets, and discusses the IPCC and WMO indications. IPCC (Annex II: Glossary. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. IPCC, Geneva, 2014) establishes that an extreme event should be rare and exceed selected upper and lower thresholds (10th and 90th percentiles); WMO (Guidelines on the defnition and monitoring of extreme weather and climate events-TT-DEWCE WMO 4/14/2016. World Meteorological Organization, Geneva, 2016) suggests thresholds near the ends of the range, but leaves them undetermined. The concept of “rare” relates the extreme events to the time domain and is typically expressed in terms of return period (RP). The key is to fnd the combination between “rare”, percentile and return period. In particular, two crucial items are analysed: (1) how the return period may vary in response to the choice of the threshold, in particular when it is expressed in terms of percentiles; (2) how the choice of producing a regular or irregular dataset may afect the yearly frequency and the related return periods. Some weather variables (e.g. temperature) are regular and recorded at fxed time intervals, while other phenomena (e.g. tornadoes) occur at times. Precipitation may be considered either regular, all-days being characterized by a precipitation amount from 0 (no precipitation) to the top of the range, or irregular (rainy-days only) considering a precipitation day over a selected instrumental or percentile threshold. These two modes of interpreting precipitation include a diferent number of events per year (365 or less) and generate diferent return periods. Every climatic information may be afected by this defnition. The 90th percentile applied to observations with daily frequency produces 10-day return period and the percentiles necessary to get 1 year, 10 years or other return periods are calculated. The general case of events with selected or variable frequencies, and selected percentiles, is also considered with an example of a precipitation series, two-century long.

4

Bivariate food distribution analysis under parametric copula framework: a case study for Kelantan River basin in Malaysia

Latif Shahid, Mustafa Firuza

Acta Geophysica

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2020

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Vol. 68, no. 3

821--859

EN

Flood is becoming an intensive hydro-climatic issue at the Kelantan River basin in Malaysia. Univariate frequency analysis would be unreliable due to multidimensional behaviour of food, which often demands multivariate fow exceedance probabilities. The joint distribution analysis of multiple interacting food characteristics, i.e. food peak, volume and duration, is very useful for understanding critical hydrologic behaviour at a river basin scale. In this paper, a copula-based methodology is incorporated for multivariate food frequency analysis for the 50-year annual basis food characteristics of Kelantan River basin at Guillemard bridge station in Malaysia. Investigation reveals that the Lognormal (2P), Johnson SB-4P and Gamma-3P are selected as marginal distributions for the food peak fow, volume and duration series. Several bivariate families such as mono-parametric, bi-parametric (i.e. mixed version) and rotated version of Archimedean copulas and also the elliptical copula are introduced to cover a large dependence pattern of food characteristics. The dependence parameter of bivariate copulas is estimated by the method of moments (MOM) based on the inversion of Kendall’s tau and maximum pseudo-likelihood estimator. To analytically validate and recognize most parsimonious copulas, GOF test and Cramer–von Mises distance statistics (Sn) with the parametric bootstrap method are employed. The Gaussian copula is identifed as the most justifable model for joint modelling of the food peak–volume and peak–duration combination for MOM-based parameter estimation procedure. Similarly, the Frank copula is selected as the best-ftted structure for modelling peak–duration combination based on MPL estimators, but the MOM estimator recognized Gaussian copula as most suitable for peak–volume pair. Furthermore, the best-ftted copulas are used for obtaining the joint and conditional return periods of the food characteristics

5

Reliability component differentiation in building structures made of timber

Gwóźdź M.

Technical Transactions

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2018

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Vol. 115, iss. 2

141--152

EN

The design of timber structures according to the current generation of Eurocodes results in new requirements being set for the authors of architectural and building designs with respect to the reliability management of such structures. The reliability problems should be formulated in the building permit design in an unequivocal manner, obliging the authors of the detailed design, as well as the contractors to deliver structures, which have all the operational parameters fully conforming to the expectations of the investor. Substantive and formal basics in this regard are formulated in the Eurocodes: PN-EN 1990, PN-EN 1991, PN-EN 1995 as well as in the related European codes. The reliability management problems of contemporary timber structures are related to the cubature buildings of different life spans, including buildings subjected to the climate loads characterised by several hundred year-long return periods.

PL

Projektowanie konstrukcji drewnianych wg współczesnej generacji norm europejskich stawia przed autorami projektów architektoniczno-budowlanych nowe wymagania w zakresie zarządzania niezawodnością takich obiektów. Problemy niezawodności należy sformułować w projekcie budowlanym w sposób jednoznaczny, zobowiązujący autorów projektów wykonawczych, a także firmy wykonawcze do dostarczenia konstrukcji o parametrach eksploatacyjnych zgodnych z oczekiwaniami inwestora. Podstawy merytoryczne i formalne w tym zakresie są sformułowane w Eurokodach: PN-EN 1990, PN-EN 1991, PN-EN 1995 oraz w europejskich normach pokrewnych. Problemy zarządzania niezawodnością współczesnych konstrukcji drewnianych odniesiono do przypadków budynków kubaturowych o zróżnicowanym okresie użytkowania, w tym poddanym oddziaływaniom klimatycznym o okresie powrotu nawet kilkuset lat.

6

Wyznaczanie dwuwymiarowych charakterystyk projektowych wezbrań sztormowo-roztopowych w zurbanizowanym obszarze portu morskiego w Ustce – wybrane problemy

Ciupak M.

Przegląd Geofizyczny

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2017

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Z. 3-4

153--177

PL

W artykule poruszono problematykę interpretacji wyników analizy dwuwymiarowej w odniesieniu do: 1) zasadności wyboru stochastycznego modelu w warunkach stacjonarności i niestacjonarności wezbrania sztormowo-roztopowego, 2) porównywania okresów powtarzalności i prawdopodobieństw przewyższenia zdefiniowanych w różnych zbiorach, oraz 3) porównywania jednowymiarowych prawdopodobieństw przewyższenia z ich dwuwymiarowymi odpowiednikami. Zmienną 2D utworzyły najwyższy poziom morza zaobserwowany w czasie wezbrań sztormowych w profilu wodowskazowym Ustka HUST (cm) i korespondujący z tym zdarzeniem przepływ w ujściowym odcinku rzeki w profilu wodowskazowym Charnowo QCHA (m3s-1). Parametry łącznej dystrybuanty oszacowano za pomocą 2-wymiarowej 2-parametrowej kopuli archimedesowskiej BB1. Do obliczania charakterystyk projektowych użyto 7 funkcji łącznego i warunkowego prawdopodobieństwa zmiennej 2D (HUST, QCHA). Wykonana analiza wykazała, ze porównywanie prawdopodobieństw zdefiniowanych w różnych dziedzinach i zbiorach oraz jednowymiarowych z dwuwymiarowymi powinno być wykonywane tylko w celu zbadania błędu wynikającego z nieprawidłowego wyboru modelu probabilistycznego. Każde zjawisko może być opisane za pomocą zmiennej wielowymiarowej, natomiast często własności losowej tylko jednej zmiennej są istotne z punktu widzenia celów projektowych.

EN

The article discusses the problem of determining the bivariate design characteristics of storm-snowmelt floods. For analysis the section of estuary Slupia basin in the area which is positioned a seaport in Ustka was used. The main natural hazard that determine the functioning of the seaport are: (i) storm surges in conjunction with backwater, (ii) uncontrolled increase in water level due to ice jam on the River Slupia and ice cover of the Baltic sea, (iii) snowmelt and rainy floods, (iv) destruction of sea coasts as results of waves, wind, sea currents, and (v) the movement of sediment. Seven functions for frequency analysis of storm and snowmelt floods were compared. The copula-based 2D probability distribution was applied to statistically describe floods with two parameters: maximum water level observed in the coastal area at Ustka in the period 1967-2005 HUST [cm] and correspondent of the event the peak of discharge observed in outlet of Slupia River at Charnowo QCHA [m3s-1]. The scope of this article is focused mainly on determine the bivariate characteristics and interpretation of different the joint and conditional probabilities. This article is an attempt to answer the question whether in the nonstationary conditions of phenomena can be used relatively simple stochastic model as it has a significant impact on the practice of planning and design of water sources. The article highlighted the need to properly define the various probabilities, especially in biand multivariate analyses. Comparing the probabilities defined in different domains and in different sets comparing the univariate probability with bivariate should only be carried out to examine the error resulting from improper selection of a probabilistic model. Analyzing the frequency of extreme events such floods, droughts is best considered in terms of the joint and the conditional probability, reasoning in terms of return period can lead to an erroneous understanding of the probability of events and incorrect description of the mechanism of this event.

7

Application of the Kineros model for predicting the effect of land use on the surface run-off Case study in Brantas sub-watershed, Klojen District, Malang City, East Java Province of Indonesia

Bisri M., Limantara L. M., Prasetyorini L., Chasanawati D.

Journal of Water and Land Development

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2017

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no. 35

3--9

EN

This study intended to illustrate the distribution of surface run-off. The methodology was by using Kineros model (kinetic run-off and erosion model). This model is a part of AGWA program which is as the development of ESRI ArcView SIG software that is as a tool for analysing hydrological phenomena in research about watershed simulating the process of infiltration, run-off depth, and erosion in a watershed of small scale such as ≤100 km2. The procedures are as follow: to analyse the run-off depth in Brantas sub-watershed, Klojen District by using Kineros model based on the land use change due to the rainfall simulation with the return period of 2 years, 5 years, 10 years, and 25 years. Results show that the difference of land use affect the surface run-off or there is the correlation between land use and surface run-off depth. The maximum surface run-off depth in the year 2000 was 134.26 mm; in 2005 it was 139.36 mm; and in 2010 it was 142.76 mm. There was no significant difference between Kineros model and observation in field, the relative error was only 9.09%.

PL

Celem badań było przedstawienie rozkładu spływu powierzchniowego za pomocą modelu Kineros (model kinetyki spływu i erozji). Model jest częścią programu AGWA, który stanowi rozwinięcie programu ESRI ArcView SIG, czyli narzędzia do analizowania zjawisk hydrologicznych w badaniach zlewni symulujących procesy infiltracji, spływu powierzchniowego i erozji w małych zlewniach o powierzchni mniejszej niż 100 km2. Procedura obejmowała analizę głębokości spływu w zlewni cząstkowej Brantas, w Dystrykcie Klojen za pomocą modelu Kineros na podstawie zmiany użytkowania ziemi i symulacji opadów z okresem powtarzalności 2, 5, 10 i 25 lat. Wyniki wskazują, że różnice w użytkowaniu ziemi wpływają na spływ powierzchniowy i że istnieje korelacja między użytkowaniem ziemi i głębokością spływu powierzchniowego. Maksymalna głębokość spływu wynosiła 134,26 mm w roku 2000, 139,36 mm w roku 2005 i 142,76 mm w roku 2010.

8

Assessment of the Relative Largest Earthquake Hazard Level in the NW Himalaya and its Adjacent Region

Tsapanos T. M., Yadav R. B. S., Olasoglou E. M., Singh M.

Acta Geophysica

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2016

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Vol. 64, no. 2

362--378

EN

In the present study, the level of the largest earthquake hazard is assessed in 28 seismic zones of the NW Himalaya and its vicinity, which is a highly seismically active region of the world. Gumbel’s third asymptotic distribution (hereafter as GIII) is adopted for the evaluation of the largest earthquake magnitudes in these seismic zones. Instead of taking in account any type of Mmax, in the present study we consider the ω value which is the largest earthquake magnitude that a region can experience according to the GIII statistics. A function of the form Θ(ω, RP6.0) is providing in this way a relatively largest earthquake hazard scale defined by the letter K (K index). The return periods for the ω values (earthquake magnitudes) 6 or larger (RP6.0) are also calculated. According to this index, the investigated seismic zones are classified into five groups and it is shown that seismic zones 3 (Quetta of Pakistan), 11 (Hindukush), 15 (northern Pamirs), and 23 (Kangra, Himachal Pradesh of India) correspond to a “very high” K index which is 6.

9

AutoCAD Civil 3D jako narzędzie wspomagające w obliczeniach hydrologicznych

Bodziony M., Baziak B.

Czasopismo Techniczne. Środowisko

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2012

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R. 109, z. 1-Ś

13--30

PL

Gwałtowne zmiany zachodzące w reżimie wodnym wymagają coraz szybszych informacji dotyczących zagrożeń powodziowych. Polski system monitoringu jest niewystarczający, szczególnie w przypadku małych i średnich zlewni. Zmusza to do poszukiwania innych sposobów pozyskiwania danych. W artykule przedstawiono sposób interpolacji informacji topograficznych i geodezyjnych na odcinku cieku, bazując na danych uzyskanych z map lub pomiarów w terenie. Do przetwarzania danych oraz tworzenia przekrojów wykorzystano program AutoCAD Civil 3D. Tak uzyskane dane zostały zastosowane do obliczenia przepływów maksymalnych o określonym prawdopodobieństwie przewyższenia metodą formuły opadowej.

EN

Violent changes in water regime require quicker and quicker information relating to flood threats. Polish monitoring system is insufficient, in particular in the case of small and average drainage areas. This creates the necessity of searching for different ways of acquiring data. This article presents the method of interpolation of topographical and geodesy information on a section of water-course, basing on the data from maps or from the measurements in the terrain. The software used for data processing as well as sections creating was the AutoCAD Civil 3D. The achieved data were used to calculate return periods using the “rainfall formula” method.

10

Evaluation of load values using the Gumbel model

Woliński S., Pytlowany T.

Archives of Civil Engineering

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2012

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Vol. 58, nr 2

199-208

EN

The paper deals with application of the Gumbel model to evaluation of the environmental loads. According to recommendations of Eurocodes, the conventional method of determining return period and characteristic values of loads utilizes the theory of extremes and implicitly assumes that the cumulative distribution function of the annual or other basic period extremes is the Gumbel distribution. However, the extreme value theory shows that the distribution of extremes asymptotically approaches the Gumbel distribution when the number of independent observations in each observation period from which the maximum is abstracted increases to infinity. Results of calculations based on simulation show that in practice the rate of convergence is very slow and significantly depends on the type of parent results distribution, values of coefficient of variation, and number of observation periods. In this connection, a straightforward purely empirical method based on fitting a curve to the observed extremes is suggested.