scholarly journals Structural master plan of flood mitigation measures

2009 ◽  
Vol 9 (1) ◽  
pp. 61-75 ◽  
Author(s):  
A. Heidari
Keyword(s):  
Flood Control ◽  
Negative Impact ◽  
Flood Mitigation ◽  
Mitigation Measures ◽  
Master Plan ◽  
Construction Costs ◽  
Flood Peak ◽  
Karun River ◽  
Damage Reduction ◽  
Mitigation Methods

Abstract. Flood protection is one of the practical methods in damage reduction. Although it not possible to be completely protected from flood disaster but major part of damages can be reduced by mitigation plans. In this paper, the optimum flood mitigation master plan is determined by economic evaluation in trading off between the construction costs and expected value of damage reduction as the benefits. Size of the certain mitigation alternative is also be obtained by risk analysis by accepting possibility of flood overtopping. Different flood mitigation alternatives are investigated from various aspects in the Dez and Karun river floodplain areas as a case study in south west of IRAN. The results show that detention dam and flood diversion are the best alternatives of flood mitigation methods as well as enforcing the flood control purpose of upstream multipurpose reservoirs. Dyke and levees are not mostly justifiable because of negative impact on down stream by enhancing routed flood peak discharge magnitude and flood damages as well.

scholarly journals Impact of Flood Control Systems on the Probability Distribution of Floods

2021 ◽  
Author(s):  
Salvatore Manfreda ◽  
Domenico Miglino ◽  
Cinzia Albertini
Keyword(s):  
Probability Distribution ◽  
Control Systems ◽  
Flood Control ◽  
Mathematical Formulation ◽  
River Basins ◽  
Flood Mitigation ◽  
Mathematical Framework ◽  
Flood Peak ◽  
Detention Basins ◽  
The Impact

Abstract. Detention dams are one of the most effective practices for flood mitigation. Therefore, the impact of these structures on the basin hydrological response is critical for flood management and the design of flood control structures. With the aim to provide a mathematical framework to interpret the effect of flow control systems on river basin dynamics, the functional relationship between inflows and outflows is investigated and derived in a closed-form. This allowed the definition of a theoretically derived probability distribution of the peak outflows from in-line detention basins. The model has been derived assuming a rectangular hydrograph shape with a fixed duration, and a random flood peak. In the present study, the undisturbed flood distribution is assumed to be Gumbel distributed, but the proposed mathematical formulation can be extended to any other flood-peak probability distribution. A sensitivity analysis of parameters highlighted the influence of detention basin capacity and rainfall event duration on flood mitigation on the probability distribution of the peak outflows. The mathematical framework has been tested using for comparison a Monte Carlo simulation where most of the simplified assumptions used to describe the dam behaviours are removed. This allowed to demonstrate that the proposed formulation is reliable for small river basins characterized by an impulsive response. The new approach for the quantification of flood peaks in river basins characterised by the presence of artificial detention basins can be used to improve existing flood mitigation practices, support the design of flood control systems and flood risk analyses.

scholarly journals A Time-Integrated Index for Flood Risk to Resistance Capacity

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1321 ◽  
Author(s):  
Osvaldo M. Rezende ◽  
Luciana F. Guimarães ◽  
Francis M. Miranda ◽  
Assed N. Haddad ◽  
Marcelo G. Miguez
Keyword(s):  
Urban Areas ◽  
Flood Control ◽  
Urban Infrastructure ◽  
Flood Mitigation ◽  
Mitigation Measures ◽  
Open Spaces ◽  
Flood Plains ◽  
Sequence Of Events ◽  
Integrated Index ◽  
Main Target

The lack of open spaces and the intense land use occupation in flood plains makes floods in consolidated urban areas difficult to mitigate. In these areas, setting a standard pre-defined return period for projects can limit and even preclude flood mitigation actions. However, it is possible to propose flood control alternatives that are compatible with available spaces. Thus, determining how much the original risk is reduced and how significant the residual risk can be becomes the main target. In this context, a time-integrated index for risk to resistance capacity is proposed to address these questions. This index correlates the exposure of buildings and urban infrastructure to the hazard of a given flood and is then evaluated over a project horizon through a sequence of events. The proposed index is applied to the Canal do Mangue catchment, a highly urbanized watershed located in Rio de Janeiro. The results demonstrate the difficulty of designing flood mitigation measures in extremely occupied watersheds and the importance of evaluating residual risks associated with proposed projects. As an additional result, a scenario with concentrated measures is compared to another with distributed interventions, evidencing the greater coverage of the latter.

scholarly journals Estimasi Model Hidrolika Menggunakan HEC-RAS 1-D dan Tren Prediksi Strategi Mitigasi Banjir

2022 ◽  
Vol 10 (1) ◽  
pp. 39-48
Author(s):  
Rian Mantasa Salve Prastica ◽  
Asvira Ditya Siswanto
Keyword(s):  
Water Level ◽  
Flood Control ◽  
Control Strategies ◽  
Flood Mitigation ◽  
Value Engineering ◽  
Field Observations ◽  
Construction Costs ◽  
Engineering Modeling ◽  
D Model ◽  
Level Profile

Engineering modeling is becoming a trend and important because it can simulate a variety of decision scenarios to be applied in the field. With limited facilities and technology, 1-D modeling in hydraulics for flood mitigation is still a trend today. What are the weaknesses of this model and how is the prediction of future modeling trends? This study analyzes the flood modeling of the Tuntang River with the 1-D model using HEC-RAS to analyze the condition of the existing water level profile and flood mitigation scenarios with normalization. The results of the analysis show that the 1-D model can describe conditions in the field and scenarios clearly. However, the 1-D model has limitations because it cannot carry out simulations that consider aspects of construction costs, time, and budget allocation of stakeholders to determine the priority scale of disaster-affected areas. It requires a vulnerability analysis with field observations, 2-D or 3-D modeling, and the application of value engineering to optimize flood control strategies. With the advancement of technology, this trend is predicted to be something that will be done in the future.

scholarly journals Impact of detention dams on the probability distribution of floods

2021 ◽  
Vol 25 (7) ◽  
pp. 4231-4242
Author(s):  
Salvatore Manfreda ◽  
Domenico Miglino ◽  
Cinzia Albertini
Keyword(s):  
Probability Distribution ◽  
Control Systems ◽  
Flood Control ◽  
River Basins ◽  
Flood Mitigation ◽  
Mathematical Framework ◽  
Flood Peak ◽  
Detention Basins ◽  
Flood Peaks ◽  
The Impact

Abstract. Detention dams are one of the most effective practices for flood mitigation. Therefore, the impact of these structures on the basin hydrological response is critical for flood management and the design of flood control structures. With the aim of providing a mathematical framework to interpret the effect of flow control systems on river basin dynamics, the functional relationship between inflows and outflows is investigated and derived in a closed form. This allowed the definition of a theoretically derived probability distribution of the peak outflows from in-line detention basins. The model has been derived assuming a rectangular hydrograph shape with a fixed duration and a random flood peak. In the present study, the undisturbed flood peaks are assumed to be Gumbel distributed, but the proposed mathematical formulation can be extended to any other flood-peak probability distribution. A sensitivity analysis of parameters highlighted the influence of detention basin capacity and rainfall event duration on flood mitigation on the probability distribution of the peak outflows. The mathematical framework has been tested using for comparison a Monte Carlo simulation where most of the simplified assumptions used to describe the dam behaviours are removed. This allowed demonstrating that the proposed formulation is reliable for small river basins characterized by an impulsive response. The new approach for the quantification of flood peaks in river basins characterized by the presence of artificial detention basins can be used to improve existing flood mitigation practices and support the design of flood control systems and flood risk analyses.

Sewer System for Improving Flood Control in Tokyo: A Step towards a Return Period of 70 Years

1994 ◽  
Vol 29 (1-2) ◽  
pp. 303-310 ◽  
Author(s):  
Kazuyuki Higuchi ◽  
Masahiro Maeda ◽  
Yasuyuki Shintani
Keyword(s):  
Return Period ◽  
Flood Control ◽  
Rainfall Intensity ◽  
Runoff Coefficient ◽  
Large Drop ◽  
Construction Costs ◽  
Sewer System ◽  
Construction Period ◽  
Metropolitan Government ◽  
Under Construction

The Tokyo Metropolitan Government has planned future flood control for a rainfall intensity of 100 mm/hr, which corresponds to a return period of 70 years, and a runoff coefficient of 0.8. Considering that the realization of this plan requires a long construction period and high construction costs, the decision was made to proceed by stages. In the first stage, the improvement of the facilities will be based on a rainfall intensity of 75 mm/hr (presently 50 mm/hr), corresponding to a return period of 17 years, and a runoff coefficient of 0.8. In the next stage the facilities will be improved to accommodate a rainfall intensity of 100 mm/hr. In the Nakano and Suginami regions, which suffer frequently from flooding, the plan of improvement based on a rainfall intensity of 75 mm/hr is being implemented before other areas. This facility will be used as a storage sewer for the time being. The Wada-Yayoi Trunk Sewer, as a project of this plan, will have a diameter of 8 m and a 50 m earth cover. This trunk sewer will be constructed considering several constraints. To resolve these problems, hydraulic experiments as well as an inventory study have been carried out. A large drop shaft for the trunk sewer is under construction.

scholarly journals A Conflict between Traditional Flood Measures and Maintaining River Ecosystems? A Case Study Based upon the River Lærdal, Norway

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1884
Author(s):  
Ana Juárez ◽  
Knut Alfredsen ◽  
Morten Stickler ◽  
Ana Adeva-Bustos ◽  
Rodrigo Suárez ◽  
...  
Keyword(s):  
Remote Sensing Data ◽  
Freshwater Ecosystems ◽  
River Channel ◽  
Flood Mitigation ◽  
Mitigation Measures ◽  
Flood Events ◽  
Protection Measures ◽  
River Ecosystems ◽  
Hydraulic Models

Floods are among the most damaging of natural disasters, and flood events are expected to increase in magnitude and frequency with the effects of climate change and changes in land use. As a consequence, much focus has been placed on the engineering of structural flood mitigation measures in rivers. Traditional flood protection measures, such as levees and dredging of the river channel, threaten floodplains and river ecosystems, but during the last decade, sustainable reconciliation of freshwater ecosystems has increased. However, we still find many areas where these traditional measures are proposed, and it is challenging to find tools for evaluation of different measures and quantification of the possible impacts. In this paper, we focus on the river Lærdal in Norway to (i) present the dilemma between traditional flood measures and maintaining river ecosystems and (ii) quantify the efficiency and impact of different solutions based on 2D hydraulic models, remote sensing data, economics, and landscape metrics. Our results show that flood measures may be in serious conflict with environmental protection and legislation to preserve biodiversity and key nature types.

scholarly journals Hydraulic Evaluation of the Levee System Evolution on the Kurobe Alluvial Fan in the 18th and 19th Centuries

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4406
Author(s):  
Tadaharu Ishikawa ◽  
Hiroshi Senoo
Keyword(s):  
Channel Capacity ◽  
Flood Control ◽  
River Flow ◽  
Global Climate ◽  
Flow Simulation ◽  
Japan Sea ◽  
Main Channel ◽  
Alluvial Fan ◽  
Flood Peak ◽  
Levee System

The development process and flood control effects of the open-levee system, which was constructed from the mid-18th to the mid-19th centuries, on the Kurobe Alluvial Fan—a large alluvial fan located on the Japan Sea Coast of Japan’s main island—was evaluated using numerical flow simulation. The topography for the numerical simulation was determined from an old pictorial map in the 18th century and various maps after the 19th century, and the return period of the flood hydrograph was determined to be 10 years judging from the level of civil engineering of those days. The numerical results suggested the followings: The levees at the first stage were made to block the dominant divergent streams to gather the river flows together efficiently; by the completed open-levee system, excess river flow over the main channel capacity was discharged through upstream levee openings to old stream courses which were used as temporary floodways, and after the flood peak, a part of the flooded water returned to the main channel through the downstream levee openings. It is considered that the ideas of civil engineers of those days to control the floods exceeding river channel capacity, embodied in their levee arrangement, will give us hints on how to control the extraordinary floods that we should face in the near future when the scale of storms will increase due to the global climate change.

Methodology for holistic assessment of grey-green flood mitigation measures for climate change adaptation in urban basins

2021 ◽  
Vol 603 ◽  
pp. 126885
Author(s):  
Ioannis M. Kourtis ◽  
Vasilis Bellos ◽  
George Kopsiaftis ◽  
Basil Psiloglou ◽  
Vassilios A. Tsihrintzis
Keyword(s):  
Climate Change ◽  
Climate Change Adaptation ◽  
Flood Mitigation ◽  
Mitigation Measures ◽  
Holistic Assessment

GEOPHYSICAL MONITORING: NEW OPPORTUNITIES TO PRESERVE ARCHITECTURAL MONUMENTS AND GREEN DESIGN IN URBAN AREAS

2020 ◽  
Author(s):  
Zakhar Slepak
Keyword(s):  
Urban Areas ◽  
Negative Impact ◽  
Technical Condition ◽  
Green Design ◽  
World Heritage Site ◽  
Mitigation Measures ◽  
Operating Life ◽  
Geophysical Monitoring ◽  
Railway Systems ◽  
Geological Processes

A new geophysical prospecting technique developed by the author was effectively applied for these purposes in 1994–2005 within the architectural complex of the Kazan Kremlin, a UNESCO World Heritage Site. The author has developed and successfully employed a unique gravity monitoring technique consisting in independent measurements at set points and at certain time intervals in the architectural complex of the Kazan Kremlin. The results of the geophysical monitoring and geodetic surveys conducted in open areas and inside architectural monuments offer new opportunities in preserving ancient buildings. Because geophysical monitoring can identify the negative impact of active geological processes on foundations of buildings, mitigation measures can be taken in timely manner. However, because the Kazan Kremlin is a state historical and architectural museum reserve, another objective is to maintain its exterior and renovate its green design. The above technology can also be used to analyze the technical condition of high-rise buildings, industrial facilities, underground railway systems and other structures, and significantly prolong their operating life.

Simulation of karst floods with a hydrological model improved by meteorological model coupling

2021 ◽  
Keyword(s):  
Flood Control ◽  
Underground Structure ◽  
Wrf Model ◽  
Precipitation Forecast ◽  
Karst Area ◽  
Peak Time ◽  
Flood Prediction ◽  
Meteorological Model ◽  
Flood Peak ◽  
Flood Warning

Abstract Karst basins are prone to rapid flooding because of their geomorphic complexity and exposed karst landforms with low infiltration rates. Accordingly, simulating and forecasting floods in karst regions can provide important technical support for local flood control. The study area, the Liujiang karst river basin, is the most well-developed karst area in South China, and its many mountainous areas lack rainfall gauges, limiting the availability of precipitation information. Quantitative precipitation forecast (QPF) from the Weather Research and Forecasting model (WRF) and quantitative precipitation estimation (QPE) from remote sensing information by an artificial neural network cloud classification system (PERSIANN-CCS) can offer reliable precipitation estimates. Here, the distributed Karst-Liuxihe (KL) model was successfully developed from the terrestrial Liuxihe model, as reflected in improvements to its underground structure and confluence algorithm. Compared with other karst distributed models, the KL model has a relatively simple structure and small modeling data requirements, which are advantageous for flood prediction in karst areas lacking hydrogeological data. Our flood process simulation results suggested that the KL model agrees well with observations and outperforms the Liuxihe model. The average Nash coefficient, correlation coefficient, and water balance coefficient increased by 0.24, 0.19, and 0.20, respectively, and the average flood process error, flood peak error, and peak time error decreased by 13%, 11%, and 2 hours, respectively. Coupling the WRF model and PERSIANN-CCS with the KL model yielded a good performance in karst flood simulation and prediction. Notably, coupling the WRF and KL models effectively predicted the karst flood processes and provided flood prediction results with a lead time of 96 hours, which is important for flood warning and control.

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