scholarly journals Evaluation of Different Simulation Methods for Analyzing Flood Scenarios in the Danube Delta

2020 ◽  
Vol 10 (23) ◽  
pp. 8327
Author(s):  
Alexandru Banescu ◽  
Maxim Arseni ◽  
Lucian Puiu Georgescu ◽  
Eugen Rusu ◽  
Catalina Iticescu
Keyword(s):  
Flood Control ◽  
Dynamic Method ◽  
Static Method ◽  
Water Levels ◽  
The Black Sea ◽  
General Interest ◽  
Danube Delta ◽  
Simulation Accuracy ◽  
Discharge Area ◽  
Investment Promotion

The present work is focused on the analysis of flood scenarios for the settlements near the Danube discharge area into the Black Sea. From this perspective, the aim of the research is the development of flood extension maps for localities in the Danube Delta. The emphasis is on collecting the data and information needed for the entire analysis process, such as hydrological data on Danube flows and water levels (which were analyzed for 51 years), topo-bathymetric data (where 1685 cross sections were processed, measured on an 87-km section of the Danube), a digital terrain model (DTM), and others. Two methods of flood scenario analysis for the localities targeted were used in this paper. The first method was an analysis of the flood scenarios by modeling a real scenario, where it was supposed that a 20 m breach appeared in the dam which protects the localities and remained present for 24 h. The second method consisted of a Geographic Information System (GIS) analysis (static from a hydraulic point of view), where the maximum water level was superimposed over the DTM. This corresponded to a scenario in which the breach in the flood-control levee remains present for a longer period. The validated results show that the dynamic method is more efficient than the static method, both in terms of estimated flooded surfaces and in terms of simulation accuracy (taking into account more input parameters than the static method). Thus, from the obtained simulations it was observed that applying the dynamic method resulted in smaller flooded surfaces in the settlements analyzed than when considering the static method. In some cases, the differences between the flooded surfaces reached up to about 22%. This information is important and of general interest since it can be used in various fields of work, such as flood defense strategies, and investment promotion activities in the Danube discharge area or similar locations.

scholarly journals Pool Boiling Heat Transfer Coefficients in Mixtures of Water and Glycerin

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 830
Author(s):  
Viktor Vajc ◽  
Radek Šulc ◽  
Martin Dostál
Keyword(s):  
Heat Transfer ◽  
Dynamic Method ◽  
Water Mass ◽  
Heat Fluxes ◽  
Static Method ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Mean Relative Error ◽  
Mixture Effects ◽  
Mass Fractions

Heat transfer coefficients were investigated for saturated nucleate pool boiling of binary mixtures of water and glycerin at atmospheric pressure in a wide range of concentrations and heat fluxes. Mixtures with water mass fractions from 100% to 40% were boiled on a horizontal flat copper surface at heat fluxes from about 25 up to 270kWm−2. Experiments were carried out by static and dynamic method of measurement. Results of the static method show that the impact of mixture effects on heat transfer coefficient cannot be neglected and ideal heat transfer coefficient has to be corrected for all investigated concentrations and heat fluxes. Experimental data are correlated with the empirical correlation α=0.59q0.714+0.130ωw with mean relative error of 6%. Taking mixture effects into account, data are also successfully correlated with the combination of Stephan and Abdelsalam (1980) and Schlünder (1982) correlations with mean relative error of about 15%. Recommended coefficients of Schlünder correlation C0=1 and βL=2×10−4ms−1 were found to be acceptable for all investigated mixtures. The dynamic method was developed for fast measurement of heat transfer coefficients at continuous change of composition of boiling mixture. The dynamic method was tested for water–glycerin mixtures with water mass fractions from 70% down to 35%. Results of the dynamic method were found to be comparable with the static method. For water–glycerin mixtures with higher water mass fractions, precise temperature measurements are needed.

scholarly journals Late-Holocene landscape evolution and human presence in the northern Danube delta (Chilia distributary lobes)

The Holocene ◽  
2021 ◽  
pp. 095968362110191
Author(s):  
Luminița Preoteasa ◽  
Alfred Vespremeanu-Stroe ◽  
Anca Dan ◽  
Laurențiu Țuțuianu ◽  
Cristian Panaiotu ◽  
...  
Keyword(s):  
Middle Ages ◽  
Economic History ◽  
Late Holocene ◽  
Environmental Changes ◽  
Land Use Changes ◽  
Sedimentary Facies ◽  
The Black Sea ◽  
Danube Delta ◽  
Human Presence ◽  
Historical Texts

This paper documents the Late-Holocene environmental changes and human presence in the northern Danube delta using a multidisciplinary approach that combines geoscientific data with archaeological findings, historical texts, and maps. It follows the formation and progression of the Chilia distributary and the reconfiguration of socioeconomic activities. Sedimentary facies identified on five new cores by changes in texture properties, magnetic susceptibility, geochemistry, and macro- and microfauna composition together with the newly obtained chronology constrain the complex evolution of the Chilia branch as filling in a long-lasting bay and then of a giant lagoon (Thiagola) which covered most of the northern delta since the Old Danube lobe inception (ca. 7500 yrs BP) till modern Chilia development. It initiated during the Greek Antiquity (ca. 2500 yrs ar BP) at the delta apex, while in Roman times (ca. 1800 yrs BP) it pursued its slow flowing into the vast Thiagola Lagoon. The most dramatic transformations occurred in the last 800 years when the river passed east of the Chilia promontory, rapidly went through the present-day Matița-Merhei basin (several decades), and created its first open-sea outlet. Solid discharge increased in two distinct periods, once in the Middle Ages (ca. 750 yrs BP) and then in the Modern Period (ca. 150 yrs BP) due to human-induced land-use changes in the Danube watershed. The chronology of the cultural remains on the pre-deltaic Chilia promontory and the multiproxy analysis of a sediment core retrieved nearby downstream suggest the terrestrial connection of the island with the mainland in ancient times. The hitherto contended issue of the old Thiagola Lagoon and its location are redefined here, as are the original identifications of ancient and medieval toponyms and hydronyms, especially for Chilia-Licostomo, Byzantine, Genoese, Moldavian, Ottoman, and Russian trading point of great importance in the political and economic history of the Black Sea and neighboring regions.

scholarly journals Optimal Operation of Floodwater Resources Utilization of Lakes in South-to-North Water Transfer Eastern Route Project

2021 ◽  
Vol 13 (9) ◽  
pp. 4857
Author(s):  
Zitong Yang ◽  
Xianfeng Huang ◽  
Jiao Liu ◽  
Guohua Fang
Keyword(s):  
Water Level ◽  
Resource Utilization ◽  
Flood Control ◽  
Optimal Operation ◽  
Water Transfer ◽  
Water Levels ◽  
Reservoir Storage ◽  
Flood Season ◽  
Hongze Lake ◽  
North Water

In order to meet the demand of emergency water supply in the northern region without affecting normal water transfer, considering the use of the existing South-to-North Water Transfer eastern route project to explore the potential of floodwater resource utilization in the flood season of Hongze Lake and Luoma Lake in Jiangsu Province, this paper carried out relevant optimal operating research. First, the hydraulic linkages between the lakes were generalized, then the water resources allocation mode and the scale of existing projects were clarified. After that, the actual available amount of flood resources in the lakes was evaluated. The average annual available floodwater resources in 2003–2017 was 1.49 billion m3, and the maximum available capacity was 30.84 billion m3. Then, using the floodwater resource utilization method of multi period flood limited water levels, the research period was divided into the main flood season (15 July to 15 August) and the later flood season (16 August to 10 September, 11 September to 30 September) by the Systematic Clustering Analysis method. After the flood control calculation, the limited water level of Hongze Lake in the later flood season can be raised from 12.5 m to 13.0 m, and the capacity of reservoir storage can increase to 696 million m3. The limited water level of Luoma Lake can be raised from 22.5 m to 23.0 m (16 August to 10 September), 23.5 m (11 September to 30 September), and the capacity of reservoir storage can increase from 150 to 300 million m3. Finally, establishing the floodwater resource optimization model of the lake group with the goals of maximizing the floodwater transfer amount and minimizing the flood control risk rate, the optimal water allocation scheme is obtained through the optimization algorithm.

Ice jam mitigation

1990 ◽  
Vol 17 (5) ◽  
pp. 675-685 ◽  
Author(s):  
Harold S. Belore ◽  
Brian C. Burrell ◽  
Spyros Beltaos
Keyword(s):  
Key Words ◽  
Carrying Capacity ◽  
Flood Control ◽  
Human Life ◽  
Water Levels ◽  
Economic Losses ◽  
River Ice ◽  
Ice Jams ◽  
Ice Jam ◽  
Ice Breakup

In Canada, flooding due to the rise in water levels upstream of an ice jam, or the temporary exceedance of the flow and ice-carrying capacity of a channel upon release of an ice jam, has resulted in the loss of human life and extensive economic losses. Ice jam mitigation is a component of river ice management which includes all activities carried out to prevent or remove ice jams, or to reduce the damages that may result from an ice jam event. This paper presents a brief overview of measures to mitigate the damaging effects of ice jams and contains a discussion on their application to Canadian rivers. Key words: controlled ice breakup, flood control, ice jams, ice management, river ice.

scholarly journals The Black Sea Trout, Salmo labrax Pallas, 1814 (Pisces: Salmonidae) in Romanian Waters

2020 ◽  
Vol 77 (2) ◽  
pp. 9
Author(s):  
Călin LAȚIU ◽  
Daniel COCAN ◽  
Paul UIUIU ◽  
Andrada IHUȚ ◽  
Sabin Alexandru NICULA ◽  
...  
Keyword(s):  
Black Sea ◽  
The Black Sea ◽  
Danube Delta ◽  
Meristic Characters ◽  
Sea Trout ◽  
Research Fields ◽  
New Information ◽  
Rivers And Lakes ◽  
Recorded Data ◽  
New Hypothesis

The review assembles chronological data on Black Sea trout (Salmo labrax) from Romanian waters and brings up-to-date information related to the distribution of the species. The information used dates from 1909 to 2020 and includes books, articles, digital databases, field observations, and notes from different research fields such as ichthyology, biogeography, genetics, aquaculture, conservation, and ecology. Global distribution, migration, meristic characters, and aquaculture of the species were analyzed based on the recorded data from the specialty literature. New information related to a possible population of Salmo labrax inside the Carpathian Arch was discussed. In Romanian waters the species is found in the Black Sea, Danube, Danube Delta but the current paper proposes a new hypothesis, namely that resident populations can be found in rivers and lakes adjacent to the Carpathian Arch. The highest migration point of the Black Sea trout in the Danube was recorded near Corabia locality, Olt County, (43°46′25″N- 24°30′12″E). In the Danube Delta, it was caught in all the three branches (Sulina, Sf. Gheorghe and Chilia), and lagoonary complexes such as Razim-Sinoe. Sexually matured females were caught especially in Spring Season while unmatured specimens were caught in all seasons. Even if the species is protected under Romanian legislation, fishermen and anglers should report its presence when caught accidentally.

Applications of Data-Driven Modelling and Machine Learning in Control of Water Resources

2011 ◽  
pp. 197-217 ◽  
Author(s):  
D. P. Solomatine
Keyword(s):  
Machine Learning ◽  
Water Resources ◽  
Computational Intelligence ◽  
Flood Control ◽  
Water Levels ◽  
Data Driven ◽  
Real Time Control ◽  
Modeling And Control ◽  
Physically Based ◽  
And Control

Traditionally, management and control of water resources is based on behavior-driven or physically based models based on equations describing the behavior of water bodies. Since recently models built on the basis of large amounts of collected data are gaining popularity. This modeling approach we will call data-driven modeling; it borrows methods from various areas related to computational intelligence—machine learning, data mining, soft computing, etc. The chapter gives an overview of successful applications of several data-driven techniques in the problems of water resources management and control. The list of such applications includes: using decision trees in classifying flood conditions and water levels in the coastal zone depending on the hydrometeorological data, using artificial neural networks (ANN) and fuzzy rule-based systems for building controllers for real-time control of water resources, using ANNs and M5 model trees in flood control, using chaos theory in predicting water levels for ship guidance, etc. Conclusions are drawn on the applicability of the mentioned methods and the future role of computational intelligence in modeling and control of water resources.

scholarly journals A hydrodynamic model coupled multiple scenarios for plain river network and its application

2018 ◽  
Vol 246 ◽  
pp. 01016
Author(s):  
Zhiqiang Zeng ◽  
Ji Liang ◽  
Mingxiang Yang ◽  
Zhaocai Zeng ◽  
Yu Lang
Keyword(s):  
Water Level ◽  
Flood Control ◽  
Water Storage ◽  
River Network ◽  
Runoff Simulation ◽  
Simulation Accuracy ◽  
Storage Effects ◽  
Storage Area ◽  
Multiple Scenarios ◽  
Flood Diversion

The plain river network is not only complex in shape but also contains many complex scenarios, such as interval inflow and outflow, hydraulic structures and water storage area, etc., which increases the difficulty of runoff simulation in plain river network. To address this problem, a hydrodynamic (HD) model coupled multiple scenarios that may occur in plain river network was proposed, which was used to simulate the runoff process of the plain river network. To illustrate the proposed model, Xi River was chosen as a study area. We designed some experiments for each scenario, and the experimental results show that simulation results have good consistency with the observation. It is worth noting that the simulation accuracy of the water level is always higher than the simulation accuracy of the flow. Moreover, the runoff simulation accuracy of runoff events with large runoff is relatively high. It turns out that HD model is suitable for runoff simulation of plain river network. In addition, we compared the flood diversion effects of water storage area and sluice, and the results show that the effect of water storage area is more obvious than sluice, and the flood diversion method combined with sluice and water storage area has better flood diversion effect. In conclusion, HD model is good at simulating floodplain storage effects, backwater and the change of water level and flow under the condition of engineering dispatching, which has important guiding significance for flood control in plain river network.

scholarly journals Comparison of Large Woody Debris Prototypes in a Large Scale Non-flume Physical Model

2018 ◽  
Vol 40 ◽  
pp. 05010
Author(s):  
Brian Perry ◽  
Colin Rennie ◽  
Andrew Cornett ◽  
Paul Knox
Keyword(s):  
Physical Model ◽  
Flood Control ◽  
Large Scale ◽  
Woody Debris ◽  
Water Levels ◽  
Mitigation Strategies ◽  
Large Woody Debris ◽  
Debris Accumulation ◽  
The Impact ◽  
The City

Due to excessive rainfall in June of 2013, several rivers located in and near the City of Calgary, Canada experienced significant flooding events. These events caused severe damage to infrastructure throughout the city, precipitating a renewed interest in flood control and mitigation strategies for the area. A major potential strategy involves partial diversion of Elbow River flood water to the proposed Springbank Off-Stream Storage Reservoir. A large scale physical model study was conducted to optimize and validate the design of a portion of the new project. The goals of the physical model were to investigate diversion system behaviors such as flow rates, water levels, sediment transport and, debris accumulation, and optimize the design of new flow control structures to be constructed on the Elbow River. In order to accurately represent the behavior of debris within the system due to flooding, large woody debris created from natural sources was utilized in the physical model and its performance was compared to that of debris of the same size fabricated from pressed cylindrical wood dowels. In addition to comparing the performance of these two debris types, the impact of root wads on debris damming was also investigated. Significant differences in damming behavior was shown to exist between the natural debris and the fabricated debris, while the impact of root wad on damming affected the dam structure and formation. The results of this experiment indicate that natural debris is preferred for studies involving debris accumulation.

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