scholarly journals Scenario Analysis of Sluice Gate Operations for Evaluating Inland Flood Damage

2021 ◽  
Vol 16 (3) ◽  
pp. 429-436
Author(s):  
Hiromichi Muroi ◽  
◽  
Kensuke Mine ◽  
Yoshiki Eguchi
Keyword(s):  
Water Level ◽  
Urban Areas ◽  
High Water ◽  
Flood Damage ◽  
Sluice Gate ◽  
Flood Simulation ◽  
Gate Operation ◽  
Sewerage System ◽  
Actual Damage ◽  
Great Damage

Typhoon Hagibis, which hit Japan directly on October 12, 2019, caused great damage, including the flooding of rivers, across various parts of Japan. The Tama River, which flows north of Kawasaki City, also experienced flooding which exceeded the designed high water level; although it did not cause fluvial flooding, river water flowed into the urban areas through the sewerage system, causing unprecedented inundation damage. This damage was reproduced with the inland flood simulation model. Furthermore, we performed simulations in which the water level, precipitation, and sluice gate operation of the Tama River differed from actual conditions, and compared them with the actual damage. Based on these results, we examined methods for reducing inundation damage, such as improving the operation method of sluice gates, and confirmed their effects.

scholarly journals A Study on the Improvement of Flood Forecasting Techniques in Urban Areas by Considering Rainfall Intensity and Duration

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1883 ◽  
Author(s):  
Choo ◽  
Jo ◽  
Yun ◽  
Lee
Keyword(s):  
Water Level ◽  
Urban Areas ◽  
Prediction Method ◽  
Flood Forecasting ◽  
Flood Damage ◽  
Rainfall Data ◽  
Runoff Simulation ◽  
Flood Prediction ◽  
Prediction Techniques ◽  
Impervious Areas

Frequent localized torrential rains, excessive population density in urban areas, and increased impervious areas have led to massive flood damage that has been causing overloading of drainage systems (watersheds, reservoirs, drainage pump sites, etc.). Flood concerns are raised around the world in the events of rain. Flood forecasting, a typical nonstructural measure, was developed to help prevent repetitive flood damage. However, it is difficult to apply flood prediction techniques using training processes because training needs to be applied at every usage. Other techniques that use predicted rainfall data are also not appropriate for small watershed, such as single drainage area. Thus, in this paper, a flood prediction method is proposed by improving four criteria (50% water level, 70% water level, 100% water level, and first flooding of water pipes) in an attempt to reduce flooding in urban areas. The four criteria nodes are generated using a rainfall runoff simulation with synthetic rainfall at various durations. When applying real-time rainfall data, these nodes have the advantage of simple application. The improved flood nomograph made in this way is expected to help predict and prepare for rainstorms that can potentially cause flood damage.

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.

scholarly journals A Study on Urban Inundation Using SWMM in Busan, Korea, Using Existing Dams and Artificial Underground Waterways

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1708
Author(s):  
Yeon-Moon Choo ◽  
Sang-Bo Sim ◽  
Yeon-Woong Choe
Keyword(s):  
Climate Change ◽  
Urban Areas ◽  
Flood Damage ◽  
Virtual Model ◽  
Sustainable Cities ◽  
Annual Average ◽  
New Methods ◽  
Average Rainfall ◽  
Reduction Methods ◽  
Urbanized Areas

The annual average rainfall in Busan area is increasing, causing frequent flooding of Busan’s Suyeong and Oncheon rivers. Due to the increase in urbanized areas and climate change, it is difficult to reduce flood damage. Therefore, new methods are needed to reduce urban inundation. This study models the effects of three flood reduction methods involving Oncheon River, Suyeong River, and the Hoedong Dam, which is situated on the Suyeong. Using EPA-SWMM, a virtual model of the dam and the rivers was created, then modified with changes to the dam’s height, the installation of a floodgate on the dam, and the creation of an underground waterway to carry excess flow from the Oncheon to the Hoedong Dam. The results of this study show that increasing the height of the dam by 3 m, 4 m, or 6 m led to a 27%, 37%, and 48% reduction in flooding, respectively, on the Suyeong River. It was also found that installing a floodgate of 10 × 4 m, 15 × 4 m, or 20 × 4 min the dam would result in a flood reduction of 2.7% and 2.9%, respectively. Furthermore, the construction of the underground waterway could lead to an expected 25% flood reduction in the Oncheon River. Measures such as these offer the potential to protect the lives and property of citizens in densely populated urban areas and develop sustainable cities and communities. Therefore, the modifications to the dam and the underground waterway proposed in this study are considered to be useful.

Bi-directional Coupling of an Unstructured Triangular Meshes-based Integrated Hydrodynamic Model for Heterogeneous Feature-based Urban Flood Simulation

2021 ◽  
Author(s):  
Guoqiang Peng ◽  
Zhuo Zhang ◽  
Tian Zhang ◽  
Zhiyao Song ◽  
Arif Masrur
Keyword(s):  
Water Flow ◽  
Urban Areas ◽  
Overland Flow ◽  
Coupled Model ◽  
Flood Simulation ◽  
Urban Flood ◽  
Essential Condition ◽  
Flow Processes ◽  
Feature Based ◽  
Heterogeneous Feature

Abstract Urban pluvial flash floods have become a matter of widespread concern, as they severely impact people’s lives in urban areas. Hydrological and hydraulic models have been widely used for urban flood management and urban planning. Traditionally, to reduce the complexity of urban flood modelling and simulations, simplification or generalization methods have been used; for example, some models focus on the simulation of overland water flow, and some models focus on the simulation of the water flow in sewer systems. However, the water flow of urban floods includes both overland flow and sewer system flow. The overland flow processes are impacted by many different geographical features in what is an extremely spatially heterogeneous environment. Therefore, this article is based on two widely used models (SWMM and ANUGA) that are coupled to develop a bi-directional method of simulating water flow processes in urban areas. The open source overland flow model uses the unstructured triangular as the spatial discretization scheme. The unstructured triangular-based hydraulic model can be better used to capture the spatial heterogeneity of the urban surfaces. So, the unstructured triangular-based model is an essential condition for heterogeneous feature-based urban flood simulation. The experiments indicate that the proposed coupled model in this article can accurately depict surface waterlogged areas and that the heterogeneous feature-based urban flood model can be used to determine different types of urban flow processes.

scholarly journals Proglacial river dataset from the Akuliarusiarsuup Kuua River northern tributary, Southwest Greenland, 2008–2010

2011 ◽  
Vol 4 (1) ◽  
pp. 71-97 ◽  
Author(s):  
A. K. Rennermalm ◽  
L. C. Smith ◽  
V. W. Chu ◽  
R. R. Forster ◽  
J. E. Box ◽  
...  
Keyword(s):  
Water Level ◽  
Statistical Tests ◽  
Ice Sheet ◽  
High Water ◽  
Stream Channels ◽  
Discharge Data ◽  
Lake Water Level ◽  
Considerable Uncertainty ◽  
Added Uncertainty ◽  
Southwest Greenland

Abstract. Pressing scientific questions concerning the Greenland ice sheet's climatic sensitivity, hydrology, and contributions to current and future sea level rise require hydrological datasets to resolve. While direct observations of ice sheet meltwater losses can be obtained in terrestrial rivers draining the ice sheet and from lake levels, few such datasets exist. We present a new dataset of meltwater river discharge for the vicinity of Kangerlussuaq, Southwest Greenland. The dataset contains measurements of river water level and discharge for three sites along the Akuliarusiarsuup Kuua (Watson) River's northern tributary, with 30 min temporal resolution between June 2008 and August 2010. Additional data of water temperature, air pressure, and lake water level and temperature are also provided. Discharge data were measured at sites with near-ideal properties for such data collection. Regardless, high water bedload and turbulent flow introduce considerable uncertainty. These were constrained and quantified using statistical techniques, which revealed that the greatest discharge data uncertainties are associated with streambed elevation change and measurements. Large portions of stream channels deepened according to statistical tests, but poor precision of streambed depth measurements also added uncertainty. Data will periodically be extended, and are available in Open Access at doi:10.1594/PANGAEA.762818.

scholarly journals EXTRACTION AND VISUALIZATION OF 3D BUILDING MODELS IN URBAN AREAS FOR FLOOD SIMULATION

2019 ◽  
Vol XLII-2/W11 ◽  
pp. 669-673 ◽  
Author(s):  
C. E. Kilsedar ◽  
F. Fissore ◽  
F. Pirotti ◽  
M. A. Brovelli
Keyword(s):  
Urban Areas ◽  
Three Dimensional ◽  
Decision Makers ◽  
Three Dimensions ◽  
Adaptation Measures ◽  
Flood Simulation ◽  
Domain Experts ◽  
Effective Strategies ◽  
Web Map ◽  
Building Models

<p><strong>Abstract.</strong> Floods pose a risk that is likely to worsen in the future due to climate change. Therefore, it is essential that decision makers and domain experts have the tools to evaluate the effects of floods. We developed a tool that visualizes the earth and buildings in three dimensions to simulate floods so that effective strategies can be developed to enhance resilience and mitigate the effects of floods. We opted to use open standards and free and open source software (FOSS) for Web to maximize interoperability, replicability, reusability, and accessibility. As a result of the literature review, we decided to use CityGML and CesiumJS for three-dimensional geospatial data visualization. However, as CityGML data is not available for the cities that our project focuses on, we developed software called shp2city that converts Esri shapefile to CityGML data in LOD1 or LOD2. Moreover, as CityGML data cannot be immediately used with CesiumJS, we used 3DCityDB to store, represent, and manage the CityGML data; 3DCityDB Importer/Exporter to export the CityGML data in KML/COLLADA/glTF format to be used within the 3DCityDB Web-Map-Client that is based on CesiumJS for visualization. Finally, we simulated floods to aid in the informed decision-making process regarding adaptation measures and mitigation of flooding effects.</p>

scholarly journals NON-BREAKING AND BREAKING WAVE LOADS ON A COOLING WATER OUTFALL

1978 ◽  
Vol 1 (16) ◽  
pp. 148
Author(s):  
G.R. Mogridge ◽  
W.W. Jamieson
Keyword(s):  
Water Level ◽  
Cooling Water ◽  
High Water ◽  
Breaking Waves ◽  
Irregular Waves ◽  
Scale Model ◽  
Breaking Wave ◽  
Wave Loads ◽  
Eastern Canada ◽  
Spilling Breakers

Cooling water from a power generating station in Eastern Canada is pumped to an outfall and distributed into the ocean through discharge ports in the sidewalls of a diffuser cap. The cap is essentially a shell-type structure consisting of a submerged circular cylinder 26.5 ft in diameter and 14 ft high. It is located in 25 ft of water at low water level and 54 ft at high water level. Horizontal forces, vertical forces and overturning moments exerted by waves on a 1:36 scale model of the diffuser cap were measured with and without cooling water discharging from the outfall. Tests were run with regular and irregular waves producing both non-breaking and breaking wave loads on the diffuser cap. The overturning moments measured on the diffuser cap were up to 150 percent greater than those on a solid submerged cylinder sealed to the seabed. Unlike sealed cylinders, all of the wave loads measured on the relatively open structure reached maximum values at approximately the same time. The largest wave loads were measured on the diffuser structure when it was subjected to spilling breakers at low water level. For a given wave height, the spilling breakers caused wave loads up to 100 percent greater than those due to non-breaking waves.

scholarly journals Effect of the Hydraulic Characteristics of a Stream Channel and its Surroundings on the Runoff Hydrograph

10.14311/923 ◽  
2008 ◽  
Vol 48 (1) ◽  
Author(s):  
V. Matoušek
Keyword(s):  
Urban Areas ◽  
High Capacity ◽  
High Water ◽  
Throughput Capacity ◽  
Hydraulic Characteristics ◽  
Flood Wave ◽  
Stream Channel ◽  
Storage Reservoirs ◽  
Smooth Channel ◽  
Rainfall Flood

The course and magnitude of a rainfall flood depends primarily on the intensity and duration of the rainfall event, on the morphological parameters of the watershed (e.g. its slope and shape), and on how to watershed has been exploited. A flood wave develops in the stream channel that drains the watershed, and it transforms while passing along the channel. This is particularly the case if the water spreads into floodplains and/or storage reservoirs while passing through the channel. This paper addresses an additional effect that has a significant influence on the magnitude and course of the flood wave but has not previously been addressed adequately, namely the effect of the hydraulic parameters of the stream channel itself on the transformation of a flood wave. The paper explains theoretically and shows on a practical example that a smooth channel with a high capacity significantly increases the magnitude and speed of a flood wave.Many flood events are unnecessarily severe just because the watershed is drained by a hydraulically inappropriate channel. The channel is large and smooth and therefore it gathers most of the flowing water during the flood event, producing high water velocity in the channel. As a result, the large and smooth channel accelerates the runoff from the watershed and constrains the spread of water into the floodplain. A high and steep flood wave is developed in the channel, and this floods areas with a limited water-throughput capacity (e.g. urban areas in the vicinity of hydraulic structures) downstream the channel. This paper offers a methodology for evaluating the ability of a channel to convey a flood wave safely and for recognizing whether a regulated channel should be subjected to restoration due to its inability to convey flood waves safely. 

scholarly journals Distribution of coastal high water level during extreme events around the UK and Irish coasts

2021 ◽  
Author(s):  
Julia Rulent ◽  
Lucy M. Bricheno ◽  
Mattias J. A. Green ◽  
Ivan D. Haigh ◽  
Huw Lewis
Keyword(s):  
Water Level ◽  
Extreme Events ◽  
High Tide ◽  
High Water ◽  
Relative Contribution ◽  
High Flood ◽  
Environmental Prediction ◽  
The Uk ◽  
Total Water Level ◽  
Tidal Stage

Abstract. The interaction between waves, surges and astronomical tides can lead to high coastal total water level (TWL), which can in turn lead to coastal flooding. Here, a high resolution (1.5 km) simulation from a UK-focused regional coupled environmental prediction system is used to investigate the extreme events of winter 2013/4 around the UK and Irish coasts. The aim is to analyse the spatial distribution of coastal TWL and its components during this period by assessing 1- the relative contribution of different TWL components around the coast, 2- how extreme waves, surges and tide interacted and if they occurred simultaneously 3- if this has implications in defining the severity of coastal hazard conditions. The TWL components’ coastal distribution in winter 2013/4 was not constant in space, impacting differently over different regions. High (> 90th percentile) waves and surges occurred simultaneously at any tidal stage, including high tide (7.7 % of cases), but more often over the flood tide. During periods of high flood risk a hazard proxy, defined as the sum of the sea surface height and half the significant wave height, at least doubled from average over ¾ of the coast. These results have important implications for the risk management sector.

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