Flood Control Works Research Articles

A Cohort-based Location Equilibrium Model with Fuzzy Reasoning and GIS Data

In the present study, the location equilibrium model was built which has three advantages. They are 1) application of fuzzy reasoning for describing ambiguity and complexity in the location choice behavior, 2) using the GIS data for performing the detailed spatial analysis in urban area and 3) make use of the rules of fuzzy reasoning for analyzing the change of Cohort-based urban population distribution for the horizon years. This model evaluated the effect on the change of location distribution caused by the flood control works and the flood risk perception of citizens. As a result of that, the significance of implementing the promotion measure of flood risk perception was shown.

洪水による都市域の浸水区域特定へのレーダーリモートセンシングデータ（ラダルサット）の適用性について

洪水災害マネジメントにおいて詳細な洪水区域図は必須条件である．冠水し易い区域の特定に基づいて詳細な洪水災害の情報を得る手法を用いれば，損失を引き起こす洪水を最小限に抑えることができる．本研究では，レーダーリモートセンシング（ラダルサット）のデータを利用してこれを評価し，バングラデシュ国のダッカ市で1998年に発生した洪水に伴う浸水区域の分布を高い精度で抽出した．適切な洪水対策を講じるために有用と考えられる最大浸水区域を正確に特定するために，洪水期間の7画像と乾期の1画像を使用した．レーダー画像をデジタル処理してピクセルデータに変換し，微小ノイズを除去するためにフィルタリング処理を施した．最大尤度判定規則を用いて画像を浸水区域と非浸水区域に区分した．レーダーデータの区分の精度は，地表データを参照して評価した．洪水の多時点解析によると，浸水区域は1998年7月（浸水率34.65％）から増加し始め，主にモンスーン性の豪雨と河川水位の早い時期の上昇により8月25日にピークを迎えた（浸水率51.29％）ことが明らかとなった．市内東部では深刻な洪水被害が発生した一方で，西部では相対的に標高が高く洪水制御設備も完成していたことから被害はなかった．画像の区分の精度からは，本研究で用いたデータ画像は十分な結果を得られたことは明らかである．最も高い精度だったのは7月31日の画像で88.57％に達し，つづいて7月7日（82.86％），9月10日（81.90％）の順となった．また，すべての画像に対して算出したKappa係数は，8月の画像をのぞいて良い一致を得た．この結果，SARデータは，ダッカ市などの急成長している都市での実時間洪水モニタリングにおいて極めて重要であり，洪水災害の情報とマネジメントのために重要な情報を与えることが可能であることが明らかとなった．

Eugenic Acculturation

In January 1939 the anthropologist Manuel Gamio toured the hinterlands of the Mexican border town of Matamoros, Tamaulipas, to examine the progress of the federal government's Valle Bajo Rio Bravo agricultural development project and to conduct an anthropological survey of the region. Over the previous four years the government of President Lazaro Cardenas had invested huge amounts of money in the construction of irrigation and flood control works in the Mexican half of the delta region of the Rio Bravo (known as the Rio Grande on the Texas side of the border) in an effort to create a cottonproducing agricultural zone that would replicate the economic growth of other cotton regions in the borderlands. The project had the goal of easing the social problems caused by the crisis of the 1930s, the most important of which was the massive re-immigration, or repatriation, of Mexicans from the United States to the border region (Carreras de Velasco, 1973; Hoffman, 1974; Balderrama and Rodriguez, 1995). The report that Gamio produced was a regional study of the environmental and social conditions in Matamoros, to be used as a guide for settling repatriated Mexican workers from Texas as small farmers in this new irrigation district.' The anthropologist concluded:

Reservoir attenuation of floods from ungauged basins

In a typical reservoir routing problem, the givens are the inflow hydrograph and reservoir characteristic functions. Flood attenuation investigations can be easily accomplished using a hydrological or hydraulic routing of the inflow hydrograph to obtain the reservoir outflow hydrograph, unless the inflow hydrograph is unavailable. Although attempts for runoff simulation have been made in ungauged basins, there is only a limited degree of success in special cases. Those approaches are, in general, not suitable for basins with a reservoir. The objective of this study is to propose a procedure for flood attenuation estimation in ungauged reservoir basins. In this study, a kinematic-wave based geomorphic IUH model was adopted. The reservoir inflow hydrograph was generated through convolution integration using the rainfall excess and basin geomorphic information. Consequently, a fourth-order Runge-Kutta method was used to route the inflow hydrograph to obtain the reservoir outflow hydrograph without the aid of recorded flow data. Flood attenuation was estimated through the analysis of the inflow and outflow hydrographs of the reservoir. An ungauged reservoir basin in southern Taiwan is presented as an example to show the applicability of the proposed analytical procedure. The analytical results provide valuable information for downstream flood control work for different return periods.

The Simple Benefit Measurement Method of Natural Disaster Prevention Projects

The uncertainty and spatiality which are characteristics of disasters, to measure the benefit of natural disaster prevention projects must be caught. This paper proposed the simple benefit measurement method that is able to use in the practical cost benefit analysis. I constructed the socioeconomic model under uncertainty, defined benefit with Non-Contingent EV, showed the incidence form, and led the form based on the characteristic which benefit was cancelled in the markets. And I proposed the short cut method to be able to measure benefit simply and approximately. It was confirmed that the value of an approximation is obtained, by measuring the benefit of the flood control works.

RESEARCH: Evaluating Sustainability of Watershed Resources Management Through Wetland Functional Analysis.

/ Unsustainable agricultural policies and water and soil resource schemes have drained two thirds of Mediterranean wetlands since 1920. An outstanding example is Karla in Greece, a former internationally important wetland that was drained in 1962 causing environmental, social, and water and soil problems. The objective of this study was to assess the functions and values of Karla, at three periods of its history, and to relate them to major events in the management of the water and soil resources of its watershed. Information on wetland and watershed features was collectedfrom historical records and field visits. The results showed that the wetland in its pristine state had performed five functions to a high degree, one (groundwater recharge) to a moderate degree, and one (flood storage) to a low degree. Flood-control works, uncontrolled pumping, etc., in 1936-1961 degraded all functions except microclimate modification while, the bird support function was moderately altered. Drainage works in 1962 left a very small artificially flooded wetland with only four functions performed to an insignificant degree. Value degradation followed function degradation. It was concluded that past resource management has been nonintegrated. No consideration was given to the multiple functions and values of Karla. Previous restoration proposals involved the reinstatement of one or two functions only. The appropriate restoration scheme for Karla must be multiobjective and based on the integrated resource management of its own and the neighboring watersheds.KEY WORDS: Soil and water resources; Sustainability; Watershed management; Wetland functional analysis; Karla wetlandhttp://link.springer-ny.com/link/service/journals/00267/bibs/24n2p193.html

Flood protection and management: quo vadimus?

In the last decade, there have been many destructive floods in various parts of the world. Despite the extensive investment in flood control works, neither flood occurrences nor damages are decreasing. A possible consequence of climate change is an increased frequency of extreme meteorological events that may cause floods. Discussion is offered of some recent large floods in the world and of the experiences in combating floods in Japan. Floods change over time as societies change. There is no single universal remedy against floods and site-specific local efforts are necessary. It is essential to undertake damage mitigation measures together with physical control measures for flood management in an integrated approach, using a mixture of structural and non-structural means. A more disaster conscious society needs to be built with better preparedness and safe-fail (safe in failure) rather than, unrealistic, fail-safe (safe from failure) design of flood defences.

A Study on Flood Control Policy of Toyama Prefecture in the Meiji Era

This paper deals with the flood control works of Toyama prefecture in the Meiji era which has been suffered from flood disasters from ancient times, clarifying the historical process in executing flood control works from both administrative and financial aspect and also discusses the historical materials of flood control which is proposed to prefectural consultative committee in consideration of the social backgrounds at the that times.It is verified that flood control works in Toyama prefecture has played pioneering role in both field of regulations and engineering compared to other prefectures, which however, resulted in a large burden to the resident people.

CALCULATION OF FLOW AND BED DEFORMATION IN COMPOUND CHANNEL WITH A SERIES OF VERICAL DROP SPILWAYS

Compound channel with a series of vertical drop spillways in low water channel is popular countermeasure for flood and sediment control works in Japan, especially in steep slope rivers. The main river flowing through the city of Sapporo, Toyohira River, has 8 low head dams in low water channel with a few hundred meters of interval. It is desired from engineering viewpoint to evaluate hydraulic functions, effect and existing problems in such compound channel rivers. In this paper, a numerical model to simulate flow and bed deformation in compound channel with a series of vertical drop spillways is depveloped. Calculated results are compared with the results obtained in moveable bed experiment.

Harmonization between flood control works and cultural properties

Harmonization between flood control works and cultural properties

Geomorphological zoning for flood inundation using satellite data

The authors investigated geomorphological features on the central plain of Thailand utilizing satellite remote sensing data and made geomorphological land classification map showing flood-stricken area. Land classification maps showing flood-striken area tell us former flood inundation area, such as inundation depth, inundation width, flood flow course and flood direction, as well as estimating of the features of flooding. Thus map is useful for planning of flood control works.

The Benefit Evaluation of The Flood Control Works with Location Equilibrium Model

The past benefit evaluation of the flood control works is nothing but object of reducing damage cost, don't seize change for state probability, that is uncertainty, land use change due to location choice action, and extend effect.In this paper, we constructed Location Equilibrium Model based on multispace general equilibrium theory under uncertainty. And we defined the benefit, expanded the concept of Equivalent Variation, proposed Non-Contingent EV including the benefits of change for state and location choice probability, as the most rational definition for evaluation.The applicable possibility of Location Equilibrium Model, Benefit Evaluation was shown through a case study.

Les évacuateurs de crues en labyrinthe : dimensionnement, fonctionnement, exemples et particularités

The purpose of this paper is to demonstrate that labyrinth spillways can be a better option than rectilinear ones. The stages that have led to development of the labyrinth spillway are briefly reviewed as are applicable design and calculation principles. Discharge flow diagrams given by Hay and Taylor, Darvas, Lux and Hinchliff, and Magalhaes and Lorena for a trapezoidal labyrinth weir are compared. Calculation procedures and design diagrams were automated, making it possible to study flood routing through a labyrinth spillway and compare its performance to that of an equivalent rectilinear spillway. A real case was used for validation: routing through the trapezoidal labyrinth weir selected for the Keddara Dam in Algeria was compared with routing through the rectilinear spillway of the initial design. Dimensions, discharge values and expected maximum heights show calculated results agree with results of experimental studies of the structure and confirm that technically the labyrinth spillway is an attractive option. Labyrinth spillways can be particularly attractive for upgrading existing developments to satisfy more demanding design flood criteria in the limited right-of-way of an existing spillway. The Sainte Brigitte-des-Saults development in Quebec on the Nicolet Sud-Ouest River is a good case in point. Key words: flood control works, spillway, labyrinth weir, polygonal weir, nonrectilinear weir.[Journal translation]

Measuring Economic Benefits of Flood Control Works

The purpose of this paper is to propose a simple and practical model in order to measure economic benefits of flood control works. This model estimates a change in both capital gain and land use due to the flood control works. Our approach is to forecast a change in land use in a small zone by adopting a growth curve method to express the difference in urbanzation between with and without the project. At the same time our model adopts a hedonic land price function which includes valuables of urbanzation and the safety level of flood. Applying this model to the S river flood control works, the benefit measured by land price change amounts to the 300 billion yen which is 10 times of its investment cost. Also comparing this result with the damage cost of 100 billion yen measured by the conventional property value method, it turns out that the indirect effect will be 2/3 of total benefits.

A study on flood control works and land use in the Toikanbetsu River Basin, northern Hokkaido

A study on flood control works and land use in the Toikanbetsu River Basin, northern Hokkaido

A Geographical Analysis of Flood Control Work and Local Share in Expenses

Sharing expenses by the residents of localities where public flood control works are to be undertaken is indispensable for the materialization of flood control works of medium and small-sized rivers in modern times. Flood prevention cooperatives organized by inhabitants in frequently-inundated areas have played an important role in bearing the expenses allotted to localities. But some of the cooperatives could not bear their share of the expenses and flood control work failed consequently.The author analyzed the causes of failure of a flood prevention cooperative in sharing expenses and clarified the problems of local share in expenses taking the case of the Kokufu River Flood Prevention Cooperative on Sado Island.The results are as follows: The most decisive reason that the Kokufu River Flood Prevention Cooperative could not bear its allotment is the impossibility of payment by the inhabitants of the upper basin, because extremely high rates of allotment in the upper basin were decided without adjusting the conflict between upper basin residents and lower basin residents. Hence prefectural river improvement work of the Kokufu River was halfed.Futhermore the following situation contributed to default in payment. In the Kokufu River basin advanced mining techniques were applied to flood control works in the Edo Period, and these works were carried out several times in connection with the prosperity and decline of the Sado Gold Mine. Some rational features in the works, imposition and repayment system, and so on can be seen. But after the Meiji Restoration small landownership in the island society prescribed repayment of much of the expenses of river improvement, and work was stopped.Therefore consideration must be given to relative flood damage between the upper basin and lower basin so as not to produce outstanding inequality between the two districts when making allotment rates.Generally, in frequently-inundated areas, we can see conflict between the uper basin and lower basin. But in that case flood control work cannot be realized without adjustment of advantages and disadvantages between the two districts. Also realization of flood control work requires the intervention of the prefectural goverment with large funds.

Effect of the Karigane Bank in the Fuji River on Maintenance of the Flow Channel

The Karigane Bank in the Fuji River was constructed as a flood control works about three hundred years ago. The bank is located at the top of the alluvial fan near the river mouth. The purpose of this study is to get hydraulic evaluation of the flood control works maintaining the flow channel. Several sets of experiments with hydraulic models including mobile bed were conducted. In each experiment, surface velocity of flow, river bed configulation after runoff and flow patterns were measured, and effect of the bank system on maintenance of the channel was discussed. The results of this study showed that the existing formation of the works with the spur dikes could separate a flood way from the retarding areas in the channel and make the works an excellent flood control system.

A Glimmer of Hope for Stream Fisheries in Mississippi

Abstract Channelization and related flood control works have severely affected most stream fisheries in the Yazoo River basin of western Mississippi. However, recovery processes appear to be quite advanced in some of these streams. A prime example is the Yalobusha River, which is one of the principal tributaries of the Yazoo River. The Yalobusha River was channelized in 1953 but stock assessments conducted in the 1980s have documented excellent fisheries in this system. Exploitable commercial and sport fishes collectively contributed 63.5–78.0% to the biomass of hoop net samples collected during 1986–88. Renewed dredging, clearing, and snagging of the Yalobusha River and other headwater streams in the Yazoo River basin are components of an overall Yazoo River basin flood control plan. These operations, if carried out, would impact the region's stream fishery resources once again. A recent statewide survey indicated that most Mississippi anglers prefer to fish in streams. Strong public opposition to the fl...

Liability as a Dilemma for Local Managers

Local governments may be sued if they tightly regulate uses in flood, erosion, avalanche, or natural hazard areas, or undertake other mitigation measures. They may also be sued if they issue permits for hazardcausing uses, increase natural or technological hazards, or fail to design or maintain adequately mitigation measures such as flood control works. How should local governments react to this dual and often serious threat of litigation? Given the current trends in the courts, are immediate constitutional challenges and claims for damages or long-term suits a greater potential problem? How can the chances of high jury awards, which can bring a local government to the verge of bankruptcy, be avoided? The following discussion focuses on this action, no action dilemma not only because it is an increasingly important issue for local governments, but because the dilemma illustrates a broad range of legal issues in hazards management.' The discussion of legal issues and trends in the courts begins with an overview of hazards litigation. Constitutional challenges to government issuance or denial of permits, planning, zoning, mitigation measures are then considered. Liability suits and trends in litigation are next examined. Finally, strategies for reducing potential liability are suggested.

Control of 1973 Mississippi River Flood

In 1973 a major flood occurred on the Mississippi River. Much of the alluvial valley of the river between Alton, Ill. and the Gulf of Mexico is protected against floods by Federally constructed flood control works. As some of these systems were not complete at the onset of the flood, a major flood fight was required to safeguard the valley. Many miles of levee had to be raised to provide proper protection. Other problems requiring flood-fight efforts were seepage under levees, scour at levees and structures, and riverbank failures. Even though major emergency efforts were required, the Federal flood control systems were effective and of great value in controlling the flood. The projects prevented the inundation of 26,000 sq miles (67,500 km²) of land and reduced flood damages by over –14,000,000,000. However, the losses sustained indicate the need to complete authorized works and possibly expand existing projects or initiate new projects in some areas, or both.