Assessment of different worst-case flood scenarios for Planinsko Polje (Slovenia)

2020 ◽  
Author(s):  
Cyril Mayaud ◽  
Franci Gabrovšek ◽  
Matej Blatnik ◽  
Blaž Kogovšek ◽  
Metka Petrič ◽  
...  
Keyword(s):  
High Water ◽  
Water Levels ◽  
Worst Case ◽  
Simultaneous Reduction ◽  
Practical Applications ◽  
Flood Duration ◽  
Maximum Water ◽  
Drainage Capacity ◽  
Extreme Flooding ◽  
Near Future

<p>Planinsko Polje is a typical example of structural polje located in South Slovenia that encounters regular flooding. The floods can occur several time per year and create a more than 10 km<sup>2</sup> large temporary lake. Even if the polje surroundings are densely populated, local people have known since centuries the average level reached by the majority of the floods and avoided constructing below it. However, the occurrence of severe events with maximum water levels far above common values is still possible. While such floods are unusual, they can last for months and drastically affect the life in the polje vicinity. As recent climatic projections expect an increase of extreme meteorological events in a near future, a resulting increase of severe floods in Planinsko Polje might be foreseen. This work aims to investigate the circumstances under which extreme flooding is occurring in Planinsko Polje. The method combines an analysis of historical flood records with a detailed description of five particular high-water events that happened during the last ten years. Then, different worst-case flood scenarios are proposed and tested with a discretized numerical model. The significance of maximum water levels and flood duration arising from modelling results is discussed in light with historical records of extreme floods. Results show that very-high flooding in Planinsko Polje is the consequence of a simultaneous reduction of the ponor drainage capacity with a combination of extreme meteorological events occurring within the polje recharge areas, while the aquifer downstream is already saturated with water. The method has practical applications for people living near Planinsko Polje and can be generalized to other poljes around the world.</p>

scholarly journals Assessment of the effect of vegetation on the transition of the flood wave using hydraulic 2D models

2018 ◽  
Vol 44 ◽  
pp. 00195
Author(s):  
Krzysztof Wolski ◽  
Tomasz Tyminski ◽  
Pawel B. Dabek
Keyword(s):  
Numerical Models ◽  
High Water ◽  
Water Levels ◽  
Lidar Data ◽  
Direct Impact ◽  
Flood Wave ◽  
Mike Flood ◽  
Flood Model ◽  
Maximum Water ◽  
Flooded Area

In the paper an impact of vegetation accumulation on flood wave transition is presented. The research was conducted with use of the MIKE FLOOD model which combines elements of 1D and 2D numerical models. The study area included a 5.5 km long section of the Bystrzyca River near Wroclaw, Poland. A hydraulic model was constructed, on which the simulation of water transition with the probability of occurrence p = 1% and p = 0.2% was conducted. The simulation was carried out for current bank vegetation conditions determined on the basis of precise LIDAR data and for conditions with no vegetation. In this way, the direct impact of vegetation on flood wave transition was obtained. Acquired results, a decrease in maximum water levels and a reduction of flooded area, show that the hydraulic influence of vegetation on high water bed should not be underestimated.

ASSESSMENT OF THE RIVERS’ MAXIMUM RUNOFF IN THE COASTAL TERRITORY OF PRIMORSKY REGION IN THE VIEW OF FLOODS HAZARD

2021 ◽  
Vol 27 (3) ◽  
pp. 6-15
Author(s):  
L. Gorbatenko ◽  
Keyword(s):  
Temporal Dynamics ◽  
Spatial Differentiation ◽  
High Water ◽  
Water Levels ◽  
Spatial Features ◽  
Maximum Water ◽  
The Russian Federation ◽  
Maximum Runoff ◽  
Coast Region

The temporal patterns and spatial features of the maximum runoff in the coastal territory of Primorsky Region in view of the floods hazard for the period from the beginning of observations to 2018, are considered. The indicator of exceeding the hazardous water level, determined by the territorial divisions of the Hydrometeorology Department of the Russian Federation, used as a criterion for identifying the most flood-prone areas. Except for the Kazachka river, all the considered watercourses are characterized by the predominance of supreme value of runoff in summer-autumn season. There is no dependence between the amplitudes of intra-annual average daily, inter-annual fluctuations of the maximum water levels and the morphometric characteristics of catchments for the rivers on the coast of Primorsky Region. But generally it is obvious that amplitudes grow with increasing a river size. The temporal dynamics of the absolute values of the maximum runoff, its anomalies and long-term water cycles of the rivers in the coastal zone of Primorsky Region are not synchronous, except for a group of neighboring rivers on the east coast, as well as the Razdolnaya river in three gaging stations. The rivers of the coast region are characterized by a complex spatial differentiation of hazardous phenomena associated with high water levels. Their recurrence differs on closely located rivers. An increase in the frequency of floods in recent years has been observed only on certain rivers as the Razdolnaya river at Novogeorgievka settlement and the Rakovka river at Opyitny settlement. The territories of the catchments of the Razdolnaya, Borisovka and Tsukanovka rivers are exposed to the greatest threats of exceeding the hazardous water levels

Alteration in tides and flood dynamics caused by channel deepening:  case study of the Saint Johns River, Florida

2021 ◽  
Author(s):  
Stefan Talke ◽  
David Jay ◽  
Ramin Familkhalili
Keyword(s):  
Numerical Modeling ◽  
Storm Surge ◽  
River Estuary ◽  
High Water ◽  
Water Levels ◽  
Tidal Range ◽  
Case Scenario ◽  
Worst Case ◽  
Length Changes ◽  
Hurricane Irma

<p>In this contribution, we show that channel deepening can amplifiy tide and storm surge--while simultaneously decreasing the river slope during both normal conditions and during floods.  We investigate the Saint Johns River Estuary, Florida, an example of a hyposynchronous, strongly frictional estuary with a landward decay in tidal amplitudes. Records since the 1890s and numerical modeling show that tidal range doubled in Jacksonville, Florida (40 km from coast), while tidal discharge approximately doubled everywhere. Overall, an increase in channel depth from 5 to 10m drove the observed changes, with width and length changes comparatively minor factors. Tidal amplitude evolved in a spatially variable way--negligible at the coast and inland, maximal 20-30km from the ocean.  The change in the M2 constituent is approximated by the equation x * exp(mu*x), where x is the distance from the ocean and mu is a damping coefficient that depends on depth, drag coefficient, and other system properties.  The observed tidal evolution is similar to storm surge:  Numerical modeling of hurricane Irma (Sept. 2017) under 1898 and 2017 bathymetric conditions confirms that both tidal and storm surge amplitudes have increased over time, with a maximum change about 20-25km from the inlet. Nonetheless, hurricane Irma produced overall high water levels in the historical bathymetric configuration. The reason is that the mean water level slope required to move water out of the modern estuary has decreased. An analytical model confirms that reduced slope is caused primarily by channel deepening.  However, greater tides and storm surge imply an increased vulnerability to a worst-case scenario hurricane. </p>

scholarly journals ASSESSMENT OF THE FREQUENCY OF DANGEROUS HYDROLOGICAL EVENTS IN THE COASTAL ZONE OF THE FAR EAST DUE TO FLOODING

2021 ◽  
Author(s):  
Л.В. Горбатенко
Keyword(s):  
Coastal Zone ◽  
Far East ◽  
High Water ◽  
Water Levels ◽  
Water Level Fluctuations ◽  
Annual Average ◽  
The Far East ◽  
Maximum Water ◽  
Annual Water ◽  
Frequency Magnitude

Рассматривались опасные гидрологические явления, связанные с высокими уровнями воды. На основе данных по 85 створам наблюдений за стоком на малых, средних и крупных реках прибрежной зоны Дальнего Востока за 2008-18 гг. проведена оценка максимальных (наивысших) годовых уровней воды. Рассчитаны внутригодовые средние и максимальные, а также межгодовые амплитуды колебаний уровней воды по каждому из створов. Проведена оценка наивысших уровней воды на основе критерия опасности - превышения значений уровней отметки опасного явления, определяемых территориальными подразделениями Росгидромета. Оценивались такие характеристики как частота, степень, а также генезис этого события. Выявлены территории региона, где опасные гидрологические события наблюдаются наиболее часто или являются наиболее сильными. Dangerous hydrological events associated with high water levels were considered. The maximum annual water levels were estimated on the basis of data from 85 stations of runoff observations on small, medium and large rivers in the coastal zone of the Far East in 2008-18. The intra-annual average and maximum, as well as inter-annual amplitudes of water level fluctuations were calculated. The maximum water levels were assessed with such hazard criterion as exceeding of the dangerous phenomenon value determined by the territorial divisions of the Federal Hydrometeorological Service. The following characteristics as the frequency, magnitude and genesis of this events were evaluated. The territories of the region with frequent or severe dangerous hydrological events are identified.

Das waldreiche obere Theresiental (Transkarpatien, Ukraine) – geografisch-ökologische und sozioökonomische Beschreibung | The forest-rich upper Theresian Valley (Transcarpathia, Ukraine): a geographic-ecological and socio-economical description

2007 ◽  
Vol 158 (1-2) ◽  
pp. 14-21
Author(s):  
Vasyl Sabadosh ◽  
Oleg Suprunenko
Keyword(s):  
Forest Management ◽  
High Water ◽  
The State ◽  
Water Levels ◽  
Private Companies ◽  
Foreign Investors ◽  
Wood Processing ◽  
Job Opportunities ◽  
Orange Revolution

The upper Theresian Valley lies along the southwest-facing ridge of the Ukrainian Carpathians. Despite expansive forestation high water levels are frequent. The forest belongs to the state and is centrally administrated. Felling is sometimes outsourced to private companies and private companies have also been founded to process the timber. Job opportunities have become fewer and illegal work is increasing. A new democratic awareness has emerged since the «Orange Revolution» in 2004. With foreign investors, however, new risks emerge. The authors recommend giving monies from forest management to the communities, the founding of new wood processing enterprises and more transparent information.

About time lag and some morphometric characteristics of streams of the forest zone

2016 ◽  
Author(s):  
Н.А. Белоногова ◽  
А.Ю. Виноградов ◽  
Т.А. Виноградова ◽  
Д.А. Догановский ◽  
А.Н. Кондратьев ◽  
...  
Keyword(s):  
Flow Velocity ◽  
Average Rate ◽  
Time Lag ◽  
High Water ◽  
Spatial And Temporal Variability ◽  
Forest Zone ◽  
Average Flow Velocity ◽  
Small Watersheds ◽  
Maximum Water ◽  
General Movement

Расчет максимальных расходов воды дождевых паводков на малых водосборах, в целях эффективного проектирования лесохозяйственных инженерных дорожных сооружений, представляет собой весьма сложную задачу вследствие отсутствия достаточных наблюдений за характеристиками дождевого стока. Кроме того, характеристики дождевого стока и определяющие их факторы обладают большой пространственной и временной изменчивостью, что еще больше затрудняет их определение. Рекомендуемая действующими нормативами методика определения максимального дождевого стока, как показывает практический опыт, нуждается в незамедлительном редактировании с точки зрения сопоставления размерностей и правильности ссылок. Особое внимание в статье уделено определению времени добегания, включенного в расчетные формулы в качестве определяющего параметра. В настоящее время понятие «время добегания» однозначно не определено. В связи с тем, что наполненность русел рек имеет высокую пространственную и временную неоднородность и изменчивость, общее движение воды в створе проектируемого инженерного сооружения можно представить достаточно упорядоченным и единообразным, с практически постоянной паводковой средней скоростью. На основе натурных наблюдений известно, что во время паводка средняя по сечению скорость потока сохраняется постоянной в пределах верхней десятипроцентной части амплитуды уровней воды. Такие данные с конца 70-х годов не публикуются. Обработка имеющихся данных говорит о том, что существует незначительное увеличение скоростей течения с ростом площади бассейнов. Поэтому предлагается принять время добегания τi, определенное по характерным отрезкам руслового пути от исследуемого створа до истока с помощью интерполяции измеренных на гидрометрических постах данных по скоростям течения. The calculation of the maximum water flow during the high water, especially on small watersheds, in order to effectively design engineering of road structures, is a very difficult task due to the lack of sufficient observations. In addition, the characteristics of rainfall, and their determinants have a high spatial and temporal variability, which further complicates their definition. Currently recommended method of determining the characteristics of the maximum rainwater, as the experience, needs immediate clarification of dimensions and verify links. Particular attention is paid to the calculation of lag time, included in the formulas as the defining parameter. Fullness riverbeds has high spatial and temporal heterogeneity and variability. The general movement of water in the closing alignment ordered and uniform. The average rate of slightly increased or decreased depending on the dryness of the season. Each cross-section corresponds to the value of average flow velocity. These data are from the late 70-ies are not published. Processing of existing data suggests that there is a slight increase in the flow velocity with increasing basin areas. Therefore, as a constant time lag is invited to take the time determined by the characteristic segments of the channel path from the source to the alignment of the test.

Forecasting the fl ood situation using space images in the city of Tavda Sverdlovsk region

2018 ◽  
Vol 934 (4) ◽  
pp. 46-52
Author(s):  
A.S. Bruskova ◽  
T.I. Levitskaya ◽  
D.M. Haydukova
Keyword(s):  
Water Levels ◽  
Economic Damage ◽  
Geoinformation System ◽  
Space Images ◽  
Geoinformation Systems ◽  
Emergency Situations ◽  
The Earth ◽  
Maximum Water ◽  
The City

Flooding is a dangerous phenomenon, causing emergency situations and causing material damage, capable of damaging health, and even death of people. To reduce the risk and economic damage from flooding, it is necessary to forecast flooding areas. An effective method of forecasting emergency situations due to flooding is the method of remote sensing of the Earth with integration into geoinformation systems. With the help of satellite imagery, a model of flooding was determined based on the example of Tavda, the Sverdlovsk Region. Space images are loaded into the geoinformation system and on their basis a series of thematic layers is created, which contains information about the zones of possible flooding at given water level marks. The determination of the area of flooding is based on the calculation of the availability of maximum water levels at hydrological stations. According to the calculated security data, for each hydrological post, flood zones are constructed by interpolation between pre-calculated flood zones of standard security. The results of the work can be used by the Main Directorate of the Ministry for Emergency Situations of Russia for the Sverdlovsk Region.

Lake and inland dunes as interconnected Systems: The story of Lake Tresssee and an adjacent dune field (Schleswig-Holstein, North Germany)

The Holocene ◽  
2020 ◽  
pp. 095968362098168
Author(s):  
Christian Stolz ◽  
Magdalena Suchora ◽  
Irena A Pidek ◽  
Alexander Fülling
Keyword(s):  
Water Level ◽  
Bronze Age ◽  
Environmental Changes ◽  
High Water ◽  
Alluvial Fan ◽  
Water Levels ◽  
Lake Area ◽  
Dune Field ◽  
The North ◽  
Sand Drift

The specific aim of the study was to investigate how four adjacent geomorphological systems – a lake, a dune field, a small alluvial fan and a slope system – responded to the same impacts. Lake Tresssee is a shallow lake in the North of Germany (Schleswig-Holstein). During the Holocene, the lake’s water surface declined drastically, predominately as a consequence of human impact. The adjacent inland dune field shows several traces of former sand drift events. Using 30 new radiocarbon ages and the results of 16 OSL samples, this study aims to create a new timeline tracing the interaction between lake and dunes, as well, as how both the lake and the dunes reacted to environmental changes. The water level of the lake is presumed to have peaked during the period before the Younger Dryas (YD; start at 10.73 ka BC). After the Boreal period (OSL age 8050 ± 690 BC) the level must have undergone fluctuations triggered by climatic events and the first human influences. The last demonstrable high water level was during the Late Bronze Age (1003–844 cal. BC). The first to the 9th century AD saw slightly shrinking water levels, and more significant ones thereafter. In the 19th century, the lake area was artificially reduced to a minimum by the human population. In the dunes, a total of seven different phases of sand drift were demonstrated for the last 13,000 years. It is one of the most precisely dated inland-dune chronologies of Central Europe. The small alluvial fan took shape mainly between the 13th and 17th centuries AD. After 1700 cal. BC (Middle Bronze Age), and again during the sixth and seventh centuries AD, we find enhanced slope activity with the formation of Holocene colluvia.

Performance of Light Coastal Structures Under Normal and High Water Conditions

1975 ◽  
Vol 2 (4) ◽  
pp. 381-391 ◽  
Author(s):  
J. W. Kamphuis
Keyword(s):  
Lake Erie ◽  
High Water ◽  
Water Levels ◽  
Coastal Protection ◽  
Coastal Structures ◽  
Water Conditions ◽  
Protection Structures

A number of lightweight coastal protection structures, built on the Lake Erie shore are discussed in this paper. There were two constraints on the design; limited funds and a very precarious downdrift beach. Thus the structures were inexpensive and the protection was low-key to prevent damage downdrift. In 1972–1974 these structures were subjected to a combination of large waves and high water levels and thus they were tested well beyond their design limits.The paper discusses the structures, their performance under normal conditions, and their performance during and after the abnormally high water levels. It is found that inexpensive, low-key structures are sufficiently strong to survive normal conditions, but fail by overtopping and flanking under conditions beyond their low design limits.

scholarly journals PRE- and POST-STORM LiDAR SURVEYS FOR ASSESSMENT OF IMPACT ON COASTAL EROSION

2019 ◽  
Vol XLII-3/W8 ◽  
pp. 261-266
Author(s):  
A.-L. Montreuil ◽  
M. Chen ◽  
A. Esquerré ◽  
R. Houthuys ◽  
R. Moelans ◽  
...  
Keyword(s):  
Management Practices ◽  
Morphological Changes ◽  
Storm Surges ◽  
High Water ◽  
Water Levels ◽  
Airborne Lidar ◽  
Coastline Change ◽  
The Mean ◽  
The Impact

<p><strong>Abstract.</strong> Sustainable management of the coastal resources requires a better understanding of the processes that drive coastline change. The coastline is a highly dynamic sea-terrestrial interface. It is affected by forcing factors such as water levels, waves, winds, and the highest and most severe changes occur during storm surges. Extreme storms are drivers responsible for rapid and sometimes dramatic changes of the coastline. The consequences of the impacts from these events entail a broad range of social, economic and natural resource considerations from threats to humans, infrastructure and habitats. This study investigates the impact of a severe storm on coastline response on a sandy multi-barred beach at the Belgian coast. Airborne LiDAR surveys acquired pre- and post-storm covering an area larger than 1 km<sup>2</sup> were analyzed and reproducible monitoring solutions adapted to assess beach morphological changes were applied. Results indicated that the coast retreated by a maximum of 14.7 m where the embryo dunes in front of the fixed dunes were vanished and the foredune undercut. Storm surge and wave attacks were probably the most energetic there. However, the response of the coastline proxies associated with the mean high water line (MHW) and dunetoe (DuneT) was spatially variable. Based on the extracted beach features, good correlations (r>0.73) were found between coastline, berm and inner intertidal bar morphology, while it was weak with the most seaward bars covered in the surveys. This highlights the role of the upper features on the beach to protect the coastline from storm erosion by reducing wave energy. The findings are of critical importance in improving our knowledge and forecasting of coastline response to storms, and also in its translation into management practices.</p>

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