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This paper demonstrates a strong motion record due to the 2016 central Tottori earthquake with JMA (Japan Meteorological Agency) magnitude 6.6. The record was originally observed by Tottori University at Takatsuji site in Yurihama town, Tottori prefecture. For future analyses, brief overview of observation with original data is provided in this paper.

Groins are usually installed to prevent bank erosion and levee damages. In Japan, gabions made by bamboo and gravels, called bamboo gabions in this paper, have been used traditionally in the construction works of rivers, however they are not frequently used recently due to the cost and high efforts of their production. Many rivers in Japan and world are now facing environmental problems associated with channel degradation or aggradation. The Kizu River, which flows north in Kyoto Prefecture, Japan, is a granite sandy river, and invertebrate and fish species were originally poor due to the fine bed materials and very flat and uniform topography. Due to constructions of dams upstream, beds became coarser and species richness became higher in the river during several decades. However, river managers are planning to sluice of sediments through the reservoir outlet to prevent over-degradation of the channel, which can induce re-appearance of fine and simple bed conditions unsuitable for river biota. Thus, we should take any measures to keep and improve more preferable condition. In the floodplain and riverside area, bamboo forest has been expanding due to reduction in flood disturbance and harvesting. The local residents and municipality are now seeking to better utilize bamboo again to stop expansion of the bamboo forest.This paper main objectives are to: 1) focus on the specific features of bamboo gabions, which fit in nature and ecosystem, from views of maintaining suitable river habitats and well-utilizing bamboos; 2) examine the effect of bamboo gabions as groin on riverine invertebrate and fish habitats, we installed the gabions and monitored the changes in bed topography, bed materials and animal community in a lower reach of the Kizu River.

Offshore wind power station is strongly demanded to complete the zero-emission society. The stations are usually located in shallow water areas where sea waves and currents may cause the scouring in the monopile-support ground. In order to prevent the scouring at the footstep of the monopile, a permeable and flexible filter-unit is developed. The unit is composed with the strong outside net and inner rubbles. The paper describes the experimental study on the stability of the unit in the stormy wave and currents. The test is done in a large basin 45m long and 4m wide and the scale of the model is 1/60. The limitation wave height and current velocity for 8ton unit is revealed.

IoT devices are expected to enable inexpensive and easy measurement and collection of a wide range of environmental information, especially in the field of disaster prevention. Whereas, preliminary verification is difficult, because of a functional design that assumes their distributed deployment, the cost of development itself. Therefore, we develop a sensor system emulator with CyReal concept, which integrates the virtual device with the actual device, and federated with other simulators. This paper presents a prototype of our sensor system, its feasible performance, and discusses a design for flexible integration, in order to support the development, update, debugging, and operation of sensor systems as a distribution network for disaster prevention information.

The Anti-Tsunami Door (ATD) is a foldable and movable tsunami mitigation facility that automatically stands up to prevent the intrusion of waves when a tsunami occurs. In this study, the conditions required for the practical application of the ATD were examined from both the hydraulic model experiment and the numerical analysis. A numerical analysis model was constructed using OpenFOAM, and the tsunami mitigation effect was evaluated. The method of evaluating the performance of the ATD using only the measured wave height was inappropriate because the net tsunami mitigation effect of the embankment body could not be properly evaluated. On the other hand, the evaluation using the passing water volume data was applied to expect the tsunami reduction effect of the embankment body. The tsunami mitigation efficiency of the ATD was 70% or more. The strength analysis of the ATD was also done in the paper.

本研究では洪水による直接被害(家屋被害，作物被害)の推定手法について述べる．基本的な考え方としては洪水氾濫シミュレーションを構造格子型で実施し，グリッドセルで出力された浸水深情報を詳細なベクトル型データに属性化することにより，家屋一棟一棟、農地一区画一区画毎の経済被害リスクの推定を可能とする．本稿では，まず，滋賀県竜王町により整備されたベクトル型データを用いた家屋・農作物被害推定手続きを紹介する．その後，佐用川流域全体を対象に構造格子で統合型の降雨流出・洪水氾濫同時解析を実施し，これによる浸水深に基づいた経済被害推定を行い，実態の経済被害と推定経済被害を比較する．本稿の経済被害推定手法の汎用性は高く，かつ構造格子型で広域の降雨流出・洪水氾濫解析の有効性を示すものである．, This paper describes a framework to estimate the direct economic damages (e.g. house and crop damages) due to floodings. The basic idea is that: (1) the flood inundation simulations are carried out with a structured grid, (2) the inundation depths output in grid cells from the structured grid are transferred to the house and crop filed vector data as attributes and (3) the economic risk of each house and crop field is estimated using the attributes. In this paper first the example of the economic damage estimation using the vector data prepared by the Ryuou Town is introduced. Then, an integrated rainfall-runoff/flood inundation simulation model with a structured grid is developed and applied to the Sayogawa river catchment which recently experienced severe flood damages due to extreme rainfall. Based on the inundation depths observed and simulated with this model as well as the actual economic loss and estimated, the accuracy of the flood and economic estimation models are investigated. This paper shows the usefulness of the economic risk framework and large-scale integrated rainfall-runoff/flood inundation model.

本研究では中間財および最終財を生産する2つの産業部門を有する経済成長モデルを構築し，地域間の中間財の代替にかかる費用が被災地経済の回復過程に及ぼす影響を分析する。中間財を含むすべての財が国際的競争下にあり被災後にも地域外から代替的に中間財が調達可能な場合を考え回復過程を分析する。その際の代替にかかる費用によって被災地経済の回復過程を比較し?地域間の中間財の代替にかかる費用が高ければ被災を免れた産業にも生産量低下という「カスケード効果」が生じること?中間財の代替にかかる費用が高い場合の方が相対的に早期の回復が達成されうることを示す。またこれら2つの効果を考慮に入れて，カスケード効果の発生による経済被害総額の拡大効果の大きさを試算する。, This paper focuses on the cost of substitution of intermediate goods and investigates how it affectseconomic recovery process after a natural disaster. This paper develops a economic growth model with finalgood sector and intermediate good sector to illustrate that the cost of substitution of intermediate goods is animportant factor for expanding economic loss by inducing the "cascade effect." In addition, it illustrated thatthe cost of substitution can affect not only the amount of economic loss but also economic recovery speed.

我が国，日本では山岳域が多く存在するため地形性降雨を考慮したレーダー短時間降雨予測は必要不可欠である。本研究は地形性降雨算定手法を開発することにより，レーダー短時間降雨予測の精度向上を目指すものである。既往研究では台風の移動と台風から離れた雨域の移動とを統一的に表現可能な移流モデルに，GPV情報，AMeDAS観測値からの風速を用いて地形性降雨の概念が導入されてきた。一方本研究は水蒸気の収支について考慮し，地形性降雨の非地形性降雨に対する線形性の仮定という問題についても解決を図った。また既往研究では高度約1000mにおける風速等の値を代表値として，層厚100 mを仮定していたが，今回，大気中の複数の層を想定した。これらの新しく開発した地形性降雨算定手法を位置の一次式で移流ベクトルを設定した既往の移流モデルに適用した結果，山岳域において地形性降雨を考慮しない移流モデルに比べ予測精度が向上した。, A nonlinear effect of non-orographic rainfall on orographic rainfall is introduced into a short-term rainfall prediction method which uses Tatehira's orographic rainfall model. In the previous paper, orographic rainfall was assumed to be simply proportional to non-orographic rainfall. In the seeder-feeder mechanism ratio of capturing cloud drops by raindrops is taking a vital role. However, the ration is not proportional to the non-orgraphic rainfall intensity. This paper introduced nonlinear function in terms of the non-orographic rainfall and develops a method solving simultaneous equations composed of the function and conservation equation of cloud drop. As a result, it is found that orographic rainfall was highly overestimated in the previous paper and computed orographic rainfall intensity is too small from just a hundred-depth atmospheric layer. Therefore, the computation method further modified so that orgraphic rainfall from multi layers could be taken into consideration.

民間の知識・技術を有効に活用するため，公共事業の設計照査の民間委託が実施されるようになってきた．しかし，公共主体は民間業者による検査の質を確認することは難しく，仮に民間業者が利益を求める場合には，公共建築物の安全性は確保されない．本稿は，設計照査の民間委託に伴い発生しうる，設計者と検査者の間の4種類の結託メカニズムをモデル化する．さらに，これらの結託を防ぐ枠組みとして，設計照査の検査結果に基づく設計契約，検査契約を設計する．このとき，設計者が設計図書を作成した後に設計照査業務の入札を実施することで，結託が発生しにくい環境が実現し，さらに公共主体から設計者，検査者に支払う報酬が小さくて済むことが示される, Recently, the government tends to delegate design verification works to private sectors to use of knowledge and technology of them. But, it is not easy to check for the government to check the quality of inspection done by private sectors. This paper analyzes a framework of payment scheme to prevent moral hazards and coalitions caused by a designer and an inspector in the delegation of design verification. The paper models a mechanism of four types of coalitions, and it is shown that the coalition which is formed before a designer make a design drawing is a critical problem for a public agency.In addition, it is shown that a public agency can create an environment where a designer and an inspector are difficult to form a coalition by selecting an inspector after a designer completed a design drawing．

洪水問題について考える場合，ハザード(洪水現象)の定量的な評価に基づくリスクの同定が必要であるという立場に立って，洪水氾濫シミュレーション(ハザードの同定)から作物被害(リスク)の推定を行った。従来あまり考慮されてこなかった湛水継続時間をも推定できるような氾濫モデルを本研究において構築し，浸水深・浸水時間と作物被害率の関係表を用いて作物被害率を推定し，単位面積あたりの作物収量と単位重量あたりの作物小売価格を利用して損害額を推定した。対象地域は滋賀県日野川流域とその流域内部の竜王町とした。本研究によって，降雨，流出，内水・外水氾濫，排水，被害という一連の過程を計算する枠組みが概ね完成できた。, Identifying the agricultural risk by flooding based on the quantified hazard is vital when addressing the flood disaster problem. This paper carries out the crop damage (risk) estimation by flood based on the flood inundation (hazard) simulation. The flood inundation model developed here can simulate not only the flood inundation by bank overtopping and rainwater, but also the drainage process through the river network system. After simulating the flood inundation process, the crop damage by flood is estimated using a vulnerability index, that is, the relationship among the crop damage ratio, the inundation depth and the inundation duration. Afterwards, the economic loss is estimated with the average crop yield per area and the retail price of the rice per weight (kg) of Shiga Prefecture. The Hinogawa River, Shiga, Japan and Ryuou Town in the catchment are selected as case study sites. This paper has established a framework to assess flood risk in a river basin from rainfall, rainfall-runoff, flood inundation, drainage and the economic loss estimation.

本論文は2004年10月23日に発生した新潟県中越地震により大きな被害を受けた小千谷市の復興計画策定支援の事例から，ステークホルダーのこんな「まち」にしたという「想い」を1）如何に汲み上げ，2）それを復興計画という形式に整理するのかという，ステークホルダー参加型での復興計画策定手法のあり方を提示する事を目的とし，1）どのようにして実効性の高い計画を策定するのか，2）如何にしてステークホルダーの多様な想いを計画という形式に整理するのか，という2つの観点から小千谷市での復興計画策定プロセスの分析を行う。, This paper deals with disaster recovery and reconstruction planning process in Ojiya city which was heavily impacted from the 2004 Niigata Chuetsu Earthquake Disaster. Disaster recovery and reconstruction planning is a process of compiling ideas or visions of impacted people into a plan. Two aspects of planning, how ideas of stakeholders are compiled into a plan, and how a feasible plan is established, will be discussed in this paper. Strategic planning scheme was used for the planning and recovery and reconstruction plan of Ojiya City (draft) 1which consisted from 1 goal, 6 objectives, 31 polices and 72 programs were established through five stakeholder workshops.

洪水を予測するうえで，水文量の空間分布をどの程度の分解能で流出予測に反映するべきかを検討する。水文量の空間分布を統計的に取り扱うことができる最大の流域面積を基準面積と定義し，分布型流出モデルを用いた数値シミュレーションによりその定量化を行う。基準面積に影響する要素として，降雨の空間分布，流域特性の空間分布，河道網の効果に着目し，それらが相互に関連して基準面積を決定づける内実を明らかにする。分析の結果，流域面積が150km2から1, 500km2の範囲では，基準面積は流域面積に関わらず絶対的な大きさで決まり，河道網の効果が主にその大きさを規定していることが分かった。また，わが国の実流域を対象とした洪水予測の例では，降雨分布の位置を陽に取り扱わないことによるピーク流量の差異を5％許容すると基準面積は300km2になることが明らかになった。, This paper investigates the appropriate spatial resolution to reflect hydrologic variabilities for flood simulation with rainfall-runoff models. It defines Model Building Unit (MBU) as a maximum catchment area in which statistical representation of the input variables is acceptable. Interactions among rainfall distributions, catchment distributions, and river cannnel effects determine the size of MBU. This paper clarifies the interactions and quantifies MBU by numerical simulations with a distributed rainfall-runoff model. The simulation results showed that MBU is restricted mainly by river channel effects and it is quantified as absolute size regardless the catchment scale if it is between 150 km2 and 1500km2. MBU is 300 km2 for 5% of allowable relative peak error.

従来，水文データは標本サイズが小さく（観測年数が短く），水文頻度解析においては，確率紙を用いた図式推定法（最小二乗法）や種々の確率分布を用いた解析的方法が用いられてきた。最近，観測年数が100年を超える場所も多くなってきたので，従来の方法を改善する可能性も出てきた。ここでは，小標本（30年未満のデータセット）及び中標本（30年以上）の場合の水文頻度解析の方法を概説するとともに，100年を超えるような大標本に対して，確率分布に頼らない順序統計学的方法とBootstrap法による確率水文量の推定方法を提案し，その精度を例示した。こうした考え方は，今後ますますデータの蓄積が進む実務現場における一つの客観的な分かり易い新しい方法として一考の価値があると言えよう。, This paper describes how to estimate the T-year events (quantiles) for hydraulic systems design and planning in river basins. Traditional frequency analysis methods, which have been providing T-year quantile estimates, include the graphical analysis with probability papers for smaller samples and the parametric approach with a number of probability distribution functions (PDFs) especially for extreme hydrologic variables for larger samples. Recently many hydrological observatories are getting longer historical data and the length of record there is exceeding the return period T. This paper recommends the usage of non-parametric approach for such larger samples, because this approach avoids the difficulty of selecting the best PDF and parameter estimation method from many candidates. The bootstrap method, which is one of the resampling methods, is used for bias correction and quantification of quantile estimation errors. A basic idea and its application results are illustrated here to indicate a direction of hydrologic frequency analysis in the future where more observatories will have longer datasets

災害の発生以前から地域が災害への対応能力を向上させるためには，リスクに直面する住民と，専門家が各々の問題意識や知識を共有し対応策を講じていくのが望ましい。本研究では，地域防災の専門家であるNPOと住民が知識共有を促進する手段として地域防災力診断アンケートを設計し，その分析結果を診断として地域に公開できるようにする。本稿では，その概念の具体的説明と東海･東南海地震を想定して行った調査の基礎的分析を行う。, We propose the method of urban diagnosis as an effective risk communication method to assess community preparedness against Tokai-Tonankai Earthquake. Urban diagnosis is a reasonable strategy to support this risk communication process. In the paper, the method of diagnosis takes the form of a questionnaire survey. Researchers contribute to the risk communication process by designing and analyzing the survey. A case study is conducted to carry out this diagnostic questionnaire. The paper discusses analysis of regional comparison, perception gap in preparedness between citizens and NPOs and assessment of opinion distributions of individual citizens in the community investigated.

大潟波浪観測所では観測専用桟橋に沿って，月に1回測深と海底底質採取を行っている。現在，観測桟橋近傍海域は侵食性の海岸であり，弧状沿岸砂州の中央部に位置している．この海域において，2003年8月23日，10月7日，2004年10月7日，11月10日に行った深浅測量と海底底質採取データを解析した。深浅測量は，汀線から沖へ約200ｍの地点を汀線に沿った1測線と，岸沖方向の2測線を行った。また，海底底質採取は，岸から沖へ水深1ｍごとに，桟橋沿いの1側線，弧状沿岸砂州接合部の岸沖方向の1側線で実施した．海底地形の変形と海底底質の粒度組成の岸沖方向変化の考察から，この海域の地形，底質の特性は，自然海浜である上下浜海岸とは異なり，年間を通して変動が急激で不規則であることがわかった。, Monthly beach profile sounding has been carrying out since 1972 along the Observation Pier, Ogata Wave Observatory, DPRI, Kyoto University by the author. Sediment sampling from the sea bottom has also been conducted. This paper reports the analyzed results of profile and sediment sampling data measured on days of Aug.23, Oct.7, 2003, Oct.7, and Nov.10, 2004. Beach profiles of alongshore sounding line 200m offshore and two cross-shore measuring lines are analyzed in this paper. Sediment sampling was conducted with 1m-pich on two cross-shore measuring lines which locate on the center and jointed lines of the crescent-shaped bar surrounding the Pier, respectively. It was made clear that both the sea bottom profiles and the grain size composition of the sea bottom sediment have changed dramatically and irregularly in all seasons in this erosion coast.

本稿は，都市地下空間の浸水被害軽減に寄与しようとするものである。まず全国の地下街の管理者を対象に行ったアンケート調査及びヒアリング調査の結果を報告する。これらの調査は，大規模地下街の浸水対策の現状と課題を明らかすることを，その目的とするものである。その結果，水害時のテナント従業員やテナント利用客の避難誘導や防災対応の現場職員の情報収集体制において対策が立ち遅れている現状が明らかとなった。特に「洪水時の情報収集」は，実際に水害対応を行うにあたって現場の防災センター職員が最も不安に感じていること，であることがアンケート調査により明らかになった。そして，これらの調査結果を総合的に整理することより，地下空間の浸水被害軽減のために必要とされる事項を抽出し，被害軽減に向けた危機管理の体系化について検討を行った。, This paper contributes to loss reduction due to inundation disasters in the underground area.In this paper, we reported the results of questionnaire and interview surveys about the present conditions ofcountermeasures against inundation disasters in the underground space. We found several problems such as informationgathering and effectiveness of countermeasures. In order to improve them, efforts of governments are expected form viewpoint of finance and regulation law. Then we discussed about necessary items for loss reduction due to inundation disastersin the underground markets, and showed the risk management system for loss reduction.

本研究では，大都市域における水管理を目的とした空間的な広がりとして河川，水道，下水道から構成される水循環圏の概念を提案し，圏域の水循環ネットワ―クが一元的に管理されることの有用性を述べる。この水循環の管理の視点として，従来から行われている水量管理，水質管理に加えて，生態系の保全に係わる河川環境の維持形成を目的とした河川流量変動の管理を行う必要のあることを指摘し，水循環の付加価値を一層高めるべきことを提案した。最後に淀川大都市域水循環圏を事例として水循環ネットワ―クとしての管理の有用性について実証的な考察を行った。, In this paper, to regard a water circulation system as a network, a concept of water circulation sphere that consistsof river basin, water supply area and sewage treatment area is proposed. In the sphere, an integrated watermanagement will be needed. Having such a concept and taking many countermeasures solve many subjects aboutan urban water management problem. This paper explained some concrete contents and pointed out about theconcrete usefulness. Furthermore, it proved about the necessity for integrated water management by showing aYodogawa water circulation sphere into an example.

筆者らが開発してきた, 山腹斜面流出系における一般的な流量流積関係式を集中化する手法を基礎として, 圃場容水量を考慮した流量流積関係式を集中化する方法について述べる。まずはじめに, 圃場容水量を考慮した流量流積関係式と, 基礎となる集中化手法の概要について説明し, つぎに, 圃場容水量を考慮した流量流積関係式に対する具体的な集中化手法を展開する。本流量流積関係式には, 関係する状態量として, 単位幅流量q, 水量hのほかに, 自由水分水量hfが媒介変数の形で含まれており, 基礎とする集中化手法をそのまま適用することができない。本論文では, 集中化の過程で行なうhによる積分操作をhfでの積分操作に置き換えることで, 本流量流積関係式の集中化を可能としている。最後に, 本流量流積関係式から導出された集中化モデルを大戸川流域と桂川流域に適用し, その結果を分布型モデルによる計算結果および観測結果と比較して, 本集中化手法の有効性と問題点を検証する。, This paper describes a method to lump a kinematic wave equation which considers field capacity of hill slope soil layer. The method is based on a method to lump a general kinematic wave equation, which has been developed by the authors. The kinematic wave equation considering field capacity and the method to lump a general kinematic wave equation are firstly shown, followed by the explanation on the method to lump the kinematic wave equation considering field capacity. This kinematic wave equation contains free water content hf in addition to discharge per unit width q and total water content h as relating state variables in the form of the parameter. Thus the lumping method which has been developed by the authors cannot be applied to this equation as it is. In this paper we develop a way to apply the lumping method to this equation by changing a variable of integration from h to hf in the lumping process. The lumped model derived from the kinematic wave equation considering field capacity is applied to simulate runoff processes of Daido River basin and Katsura River basin. Then effectiveness and problems of the lumping method are verified by comparing the results with the calculation results ofa distributed runoff model and the observation results.

防災投資の費用便益分析の実践において用いられてきた期待被害額指標は大規模被害をもたらす災害リスクの特性を反映できないという限界がある.災害リスクに対して防災投資に代表されるリスク・コントロール, 災害保険等のリスク・ファイナンスという2種類の手法がある.本研究では防災投資の費用便益分析を実施する場合, リスク・ファイナンス手法の利用可能性を明示的に考慮することが必要であることを指摘する.その上で, 防災投資の経済評価の枠組みを提示するとともに, 今後に残された研究課題をとりまとめる., The calculation of expected-losses-reduction, adopted in practices of cost-benefit analysis of disaster mitigation investment, fails to capture the catastrophic features of disaster, most typically characterized by large magnitudes of collective damage. The risk management methods to cope with castrophe disaster can be classified into two categories: risk control through mitigation of flood disaster and risk financing to allocate catastrophe risks through market transactions. The paper claims that the cost-benefit evaluation of mitigation investment should reflect social applicability of risk financing technology to take into account the catastrophic aspects of disaster. The paper presents an extended framework of economic valuation of catastrophe risk mitigation and summarizes remaining issues to be concurred in future research.

本論文では, 水資源開発を巡るコンフリクトをモデル化するとともに, 主体の選好に関する情報が不完備な場合の情報構造を定式化する。次に不完備情報下で調停者が安定でかつパレート効率的な調停案を提示するために, 安定性とパレート効率性の十分条件を特定するロバストネス分析手法について説明する。さらに本論文で提示した方法論を発電用ダムの更新整備を巡るコンフリクトに適用し, 考察を行う。, In this paper, the conflict on water resources development is modeled. Then, the information structure is formulated for the case where the information on players' preferences is incomplete. In the coordination process of the conflict, an arbitrator needs to show the alternative that is stable and Pareto efficient. In this paper, a methodology to specify necessary conditions that the concerned alternative is stable and Pareto efficient is shown.Finally, the proposed methodology is applied to the conflict on the renewal of the reservoir for hydropower generation.

都市の内水排除の排除施設を効果的に運用する場合、観測システムを明示的に考慮して運用ルールを決定することが重要であり、筆者らはルールの決定が部分観測下の最適制御問題として定式化でき, 有限な状態量の関数として定義可能であることを示した(田中他、1999)。しかし、複雑な内水排除システムでは厳密な最適制御ルールを求めることは難しい。本稿ではモデルの実用的な近似解法として観測方程式を用いた方法を提示する。, Major issues of urban drainage system control are design of control policy and monitoring system. Given a monitoring system , mathematical programming model to obtain an optimal control policy is formulated as a partially observable MDP problem. It was shown in the authors' previous paper (Tanaka, et.al. 1999) that the optimal operation policy takes the form of mapping from finite a point in state space to release volume. However, for real world problems, dimensions of state vectors tend to large enough as to prohibit direct application of the model. In order to cope with this problem, this paper presents an approximate method as to obtain sub-optimal operation policy under partially observable state information. This method contains an observation equation, which is formulated by considering hydrological characteristics. Numerical examples are also provided as to demonstrate its applicability to large-scale real world problems.

これまで, 著者らは大規模な人的被害に基づく間接被害額を平均寿命とGRPの関係を用いて評価し, その手法を1995年の阪神・淡路大震災などの災害事例に適用してきた。この手法を世界各国に適用しようとすれば, 各国の統計デ」タが必ずしも公安されていないなど問題がある。そこで本研究では, 普通死亡率と平均寿命の関係に着目することによって, 従来の手法を簡便に用いることができるようにした。その手法を1999年のトルコおよび台湾の地震に適用した結果, 人的被害による社会的価値の損失は33.3億ドルおよび30.9億ドルと推定された。, This Paper proposes a method to estimate indirect losses due to large scale natural disastersbased on the GDP (Gross Domestic Product) and the average life span. We already applied to estimate indirect losses due to the 1995 Great Hanshin-Awaji Earthquake Disaster. This approach requires death data in the damaged areas for calculation of average life span, which is not always available in many countries in the world. Therefore, we tried our conventional model to apply other countries using a correlation between the crude death rate and the average life span. In this paper, we put the method to the quakes in Turkey and in Taiwan in 1999. It was found that indirect losses in the first year were roughly estimated to be $3.33 billion in Turkey and $3.09 billion in Taiwan respectively.

海岸工学講演会で発表された論文の中から, 水理実験に関するものを抽出し, 波浪に係わる水理実験の変遷を調べることによって, 水理実験の今後の方向を検討した。その結果, 実験論文数の割合は, 今後減少していく方向にある。その中でも, 理論あるいは数値シミュレーション法の妥当性を調べる検証実験は, 電子計算機の処理速度の飛躍的な発達とともに最も多くなっており, 今後も増加する傾向にある。実験施設を整備していくにあたっては, 一様水路では不規則波造波装置が不可欠であり, 多方向不規則波造波機能を有した平面水槽の整備も併せて進めることが望ましい。, Historical change of hydraulic experiments was investigated statistically though the papers published in the proceedings of Japanese Conference on Coastal Engineering. The numeral rate of the papers on the hydraulic experiments has been dropping lately to about 30%. The confirmation experiments of the validity of theoretical analysis and numerical simulations has become major at present, comparing with other factors for hydraulic model tests. Since uni- and multi-directional random wave generators were developed, model tests in random wave have become predominant. The random wave generators in experimental flumes and basins have become inevitable facilities for hydraulic model tests.

The present paper describes the results of observational studies of Sakurajima volcanic eruption columns using an X-band marine radar. The X-band marine radar was set up at the Kurokami Observatory located approximately 4 km from the Sakurajima Minamidake vent. We carried out observations by physically changing the rotational axis of the slot antenna, from vertical to horizontal, to achieve an elevation angle resolution of 1.2°. The observation period was from April 11 to May 31, and the collected data was for a total of 57 outstanding eruptions. To our knowledge, our observations represent the first time that marine radar has been used to successfully detect eruptions and falling pyroclastic particles. The radar revealed the fine structure of an ascending eruption column at 1.25 -second intervals. The present study demonstrates that eruption source parameters such as eruption onset time, duration, height, and ascending speed can be estimated by marine radar observations.

The strain space multiple mechanism model idealizes the behavior of granular materials based on a multitude of virtual simple shear mechanisms oriented in arbitrary directions. These mechanisms idealize the micromechanical structure of granular materials with induced anisotropy and form a second-order fabric tensor, which relates macroscopic strain to macroscopic stress and has been updated to consider the effect of inherent anisotropy. This paper investigates the inherent anisotropy's effect on the evolution of induced fabric under pure shear loading. Comparison with Discrete Element Method (DEM) simulation demonstrates that the strain space multiple mechanism model accounting for inherent anisotropy has the potential to capture the essential features in the evolution of an induced fabric in granular materials subject to pure shear.

In July in 2018, a strong frontal rain system caused prolonged and torrential rainfall in the broad areas in the western Japan. While many reservoirs contributed to mitigate flood impacts by controlling flood water in the rivers, some reservoirs lost their flood control volumes to regulate river flow in the downstream by the overwhelming amount of inflow in the middle of the flood event. Those reservoirs therefore had to release the same amount of water as inflow after that, and resulted in severe inundation in the downstream in some river basins. Considering lessons learnt from this flood event, a robust reservoir operation method is proposed for flood control under extreme flood events in this paper.

本研究では, MOS-1/MESSR, マルチバンド画像データと, 多時期のJE:RS-1/SAR画像データを用い, 土地被覆分類を行う手法を検討する。さらに, セル分布型土砂流出モデルを構築し, インドネシア・ジャワ島東部のブランタス川流域に適用し, 火山噴出土砂の流出解析を行なう。MOS-1/MESSR画像データのみを用いて土地被覆分類を行なったところ, 雲がかかっていて分類できない地域や不正確な分類となっている地域が存在した。そこで, 多時期のJERS4/SAR画像データによる土地被覆分類データを統合し, マルチバンド画像データのみによるものよりも正確な土地被覆分類を行なうことができた。次に, 1990年2月のクルー山の噴火によって大量に堆積した土砂の流出を解析することを目的とし, セル分布型土砂流出モデルを構築した。このモデルは, 流域を多数のセル(250m四方の正方形領域)の集まりとする分布型モデルで, 各セルにおいてkinematicwave法により降雨流出計算を行なう。土砂の流出は雨水流量に従い, 斜面のセルでは, 地表面流の発生に伴って土砂が生産され, 河道のセルでは, 流砂量式により決定される流砂量が流下するとしたモデルである。このモデルを主要な支川の一つであるプティー川およびそれを含むクルー山南西斜面域に適用し, 土砂堆積厚の空間的および時間的変化, ブランタス川への土砂の横流入をシミュレートすることが可能となった。, This paper describes (1) a method of land cover classification that uses both multi-spectral band images of MOS- 1/MESSR and multi-temporal images of JERS- 1/SAR and (2) a grid-cell based distributed runoff model that can estimate sediment runoff from volcanic mountain slopes in the Brantas River basin, East Java, Indonesia.As for (1), this paper indicates that the use of multi-spectral band images only does not produce very good land cover map, and the combination of MOS-l/MSSR and JERS-1/SAR can obtain more accurate land cover conditions of the basin. As for (2), the runoff model, which uses land cover information as well as a 250-in digital elevation models, can evaluate transition of spatial distribution of volcanic ash on the slopes.This paper illustrates the results of computer simulation with this model on temporal and spatial distribution change of sediment yield in the Putih River basin, a tributary of the Brantas and the basins on the south slope of Mt. Kelud, which erupted on February 10, 1990.

いつも災害に見舞われる地域においては, 防災のために独自の文化ができていた可能性がある。そこで, 1996年2月6日の土石流で多くの犠牲者を出した長野県小谷村を研究対象として選び, 歴史的な災害の実態を確認する。その上で, この地域の災害に関係する伝説や習俗・諺などを収集し, 住民がいかに災害とつきあっていたかを明らかにする。災害常襲地帯の民衆の知恵を学んで、防災を進めていきたい。, Disaster prone area often have a unique culture of disaster prevention. This paper deals with the disaster culture of Otari Village, Nagano Prefecture, which was seriously damaged by debris flow on February 6, 1996. Due to this disaster, 14 people died. This paper investigates the nature and and history of disasters that have occurred in this area. Moreover, it deals with the legends, manners, customs, and proverbs that have sprung from such disasters. If we hope to prevent such disasters from occurring in the future then it is my belief that we must learn from this kind of traditional folk wisdom found in places like Otari.

不確実性下の便益評価としては無数の指標が想定しうる。本研究では, 不確実性下の便益評価指標の整合性を「符号保存性」, 「順序保存性」として定義し, 整合的な評価指標をいくつかに絞り込むことを目的とする。このような絞り込みの結果, 等価的オプション価格, 原点補整後のfairbetpointの期待値, 原点補整後のcertainty pointの期待値が整合性の条件を満たすことを明らかになった。, This paper investigate the conditions for WTP measures under uncertainty to have consistency.Conditions of consistency are defined by sign preservation and rank preservation for expected utility.A list of consistent WTP measures is presented. The paper shows that equivalent option price, expected values of fair bet point and certainty point adjusted in their origins are the sign and rank preserving WTP measures.

3次元レーダー情報を用いた既開発の短時間降雨予測手法は, 水収支を観点とした降雨の概念モデルを基礎としている。本研究では, 本手法の実用化を目的として, 以下のことを行う。まず, これまで決定論的に取り扱われてきた本手法に対して, その不確定性と確率過程的な概念を考慮すべく, カルマンフィルター理論を導入する。次に, 予測精度に影響を及ぼす因子として, 台風性降雨に対する移流ベクトルの算定手法に関する検討を行う。それらの検討の結果, 予測精度が本手法の実用化に向けて向上することがわかった。, A siort‐term rainfall prediction method using volume scanning radar immformation is physically based on a conceptual ralnifall model (instability field model) using time principles of water balance and thermo dynamics.In this paper, time nimethod is imiproved for practical use. Firstly, Kalniman Filtering theory is inmtroduced into this model to take uncertainties and stochastic concept into account, because tins conceptual model has been considered as a deterministic one.Seconmdly, this paper further discusses about a factor which influence on accuracy of prediction; a translation vector of typhoon.As a result, this rainfall prediction method including this coinceptual model is unproved for practical use by timese two studies.

This paper describes a method of stochastic parameter identification and response estimation for linear multi-degree-of-freedom structures, based on partial and noisy observations of seismic structural responses. It is an important issue to estimate the seismic structural responses and the parameters of existing structlire for safety checking, confirmation of initial design and active control system. But, owing to the limitation of observation points, the noise in observation data and the difficulty of direct observation of the state variables such as displacement and velocity responses of each story, estimation and identification from a stochastic viewpoint are needed. Particulary, in this paper, it is applied to the response estimation of a full-scale test structure at the Disaster Prevention Research Institute of Kyoto University using the observed absolute acceleration records.

To consider aeroelastic instabilities of prismatic high-rise buildings in strong winds, I.e., vortex induced oscillation or galloping, unsteady aerodynamic forces must be investigated as the external forces acting on building. From this point of view, wind tunnel experiments were performed to obtain information of the fluctuating pressure on side face of buildings, which are subjected to the forced harmonic oscillation with a fundamental linear mode in a boundary layer. In the previous paper we presented about the case of the oscillating square prism. This paper presents the characteristics of fluctuating pressures of other two type rectangular prisms. One type prism has the depth-breadth ratio equal to 2 which is the model of flow reattachment. Other type prism has the depth-breadth ratio equal to 0.5 which is the model of perfect separation. And the comparison of 3type prism (spuare and 2type rectangular prism) is discribed.

When we design large span structures like domes, it is substantial to take into consideration of influence of external forces such as earthquakes and wind. For a spherical dome, exact eigen modes are already available.In modal analysis, however, the exact modes are of little use, because they are represented in terms of Legendre bifunction with complex or real fractional order.The purpose of this paper is to get a powerful tool for response analysis of a spherical dome subjected to dynamic excitation based on mathematical analytic method, I.e., the Galerkin procedure in modal analysis, with sufficient accuracy and practicality.This paper provides an approximate solution of eigen modes, which has sufficient accuracy and practicality for response analysis in any states.

A large number of buildings suffered severe damage due to the 1995 Hyogoken-nambu earthquake. In this paper, distribution of damage to buildings was shown based on the statistical damage data. A primary factor of building damage was also investigated from both side of building structure and input motion strength. Damage was strongly affected by the kind and oldness of buildings. A lot of old wooden houses with heavy roof ware suffered severe damage. In addition, it made clear that distance to nearest fault and surface soil condition also affect distribution of damage to buildings.Distribution of Human damage was also shown based on the statistical data in this paper. Number of dead person at every site strongly related to the number of cllapsed wooden buildings.

This paper addresses the need for addition of a recreational use to multi-purpose reservoir development. The paper then proposes a systematic methodology of project evaluation where allocation of costs are combined with the assessment of benefits. Particularly, the method of evaluating the benefits of recreational use in multi-purpose reservoir development is closely discussed. It was determined that the application of the travel cost method was the most useful to the model situation assumed in this paper. Then, appropriate cost allocation schemes are discussed theoretically, based on the results from the benefits estimated for recreational use. The paper concludes with itemizing policy implications derived from this study and lists possible themes to be subject for further research.

For engineering practices groundwater level models are necessary to simulate the groundwater flow in coastal reclaimed areas which are effected by tide, rainfall and development conditions. In this paper, mathematical formulation for distribution of groundwater level is modified by considering landward boundary conditions, which is derived by using the horizontally one-dimensional assumptions.Residual water level around revetments has been decided by only considering tidal level change.However, groundwater level higher than this design level has sometime been observed in cases of heavy rainfall or where water is stored in coastal sand pits, and this causes high water pressure on the revetment and large seepage velocity sea-ward.This paper deals with such groundwater flow around revetments where the groundwater level in coastal reclaimed areas is higher than the sea level.The residual water level change and the velocity distribution of groundwater flow around sheet-pile revetments are calculated numerically by using finite element method in various conditions, and the effects of rainfall and landward boundary conditions are examined.Applying this numerical model to practical steel sheet-pile revetment which stability may be reduced by high residual water level, the effect of the proposed countermeasure method mainly composed of drainage method is discussed and the reinforcement work is executed.As a result of investigation of the practical situations of cellular concrete block-type revetment, cavitations under the pavement are found out where the armor stone and rubble foundation of revetment were damaged and the groundwater level at a distance of 19 in from revetment has risen lm by heavy rainfall.Back filling materials of this gravity-type revetment may be washed away, because seepage velocity larger than critical seepage velocity can be estimated numerically at this section.

This paper addresses the inreasing need for comprehensive urban planning which corrdinates urban planning and disaster prevention. With a focus placed on hillside cities, the paper first analzes the structure of the problem. Then, a conflict analysis is made to examine the possible outcomes of uncordinated urban planning. Thereafter more promising possibilities will be suggested by examining cordinated outcomes which might be produced if comprehensive urban planning is introduced.

The Ogura low-lying basin located in the south of Kyoto has been urbanized rapidly in recent years. To cope with changes of flood runoff due to urbanization, the improvement of the River Furu was begun in 1971, and the Kumiyama Pump station with a pump of 30 m^3/s was constructed at the downstream end of the River Furu in 1973. Moreover, a pump of 30 m^3/s was added to this pump station in 1987, and the Joyo Pump station with two pumps of 5 m^3/s was constructed at Haccho located in the upstream of the River Furu in 1990.In addition to these counter-measures, several measures have been proposed in our previous papers. The latest paper showed an optimum plan of drainage systems along the River Furu from the viewpoint of minimum cost of construction.This paper deals continually with an optimum plan of drainage systems in the whole of the Ogura basin which consists of three sub-basins such as the Jodan, the Chudan, and the Gedan Zones from the viewpoint of minimizing a total amount of annual interests, depreciation, and maintenance of drainage equipment. In particular, two counter-measures against the increase of flood runoff due to urbanization in the Nakauchi and Ouchi sub-basins situated in the western part of the Gedan Zone are examined. The one of them is the improvement of existing drainage systems in these sub-basins connected with the Gedan Main Channel through two culverts, and the other is the separation of the drainage systems from the Gedan Main Channel after closing these culverts and constructing the new drainage pump station at the downstream end of the River Ouchi.As the result, it has been clarified that there is little difference in total amount of annual cost of these measures, and that the separating plan has an advantage of reduction of annual flood damage of paddy field in the Gedan Zone.

It is commonly said that the major objective of disaster prevention is to reduce social damages caused by disasters. From this viewpoint this paper examines methods to evaluate social damages caused by disasters. Social damages caused by disasters are often evaluated by the expected losses to society (social losses). The social loss is defined as the decrease in social welfare measured in monetary term from ordinary to disaster state. It is claimed that "ex ante" and "ex post" evaluation of disaster-caused damages should be strictly distinguished. Ex ante evaluation which is conducted in planning disaster prevention facilities requires the probability distribution of social damages to be identified a priori. The paper demonstrates that the social expected loss as an evaluation criterion may well reflect the characteristics of the disasters but fail to evaluate the social preferences of the probability distributions of the resultant social damages.

The heavy rainfall event in 2018 was an extraordinary widespread and long-lasting heavy rainfall and caused a big damage. In this paper, we analyzed the abnormality of the heavy rainfall event in July 2018 in terms of some spacio-temporal scale indices, "atmospheric pattern", "the amount of water vapor inflow", and "the accumulated precipitation amount", by comparing with the ensemble output of present and future climate experiments of climate model. As a result, the frequency of similar atmospheric pattern to that of the event in 2018 will not increase in the future climate. However , the amount of water vapor inflow will remarkably increase, moreover the accumulated precipitation of meso-β localized heavy rainfall, that could be a trigger of disaster like landslide or flooding, will also become more intense in the future climate. It is indicated that the frequency of similar widespread and long-lasting heavy rainfall may not increase but if the similar one occurs, the total rainfall amount is possibly increase and the disasters will also become more severe.

The Trinity River Division of the Central Valley Project has executed since 1964 and habitat for aquatic animals have received an adverse impact from the construction of dams and transport water from the Trinity River into the Sacrament River as a part of the project. The Trinity River Restoration Program has conducted various projects to implement recovery of the Trinity River and its fish population. The objective of this paper is to estimate the mobility of the riverbed materials by tracing gravel with Passive Integrated Transponder tags (PIT-tags gravel) using Radio Frequency Identification system and to evaluate by computing the 2-dimensional (2D) model calculation for riverbed variation. From the results of the survey, we could detect the PIT-tags gravel at most 460 m downstream from the gravel injection point (IP) when floods have occurred twice after gravel injection and there is a possibility that the area of 200-250m downstream from IP seems to have a potential to catch gravel and to be a sandbar in the near future. And also we need to discuss the requirement for suitable sandbar for aquatic animal's habitat from the view point of the function of sandbar as a next work. Applying this concept would give better insights into preferable gravel augmentation method.

This paper presents a households' behavior model in drought time.In drought time, the difficulty of gaining the required amount of water increases and households are forced to reallocate their resources to produce water-dependent in-house services.In this paper, the difficulty induced by drought is expressed in terms of increased time to obtain a unit amount of water.A demand model is proposed to theoretically analyze the demand substitutions between different services as the time to gain water increases in drought time.It is shown that both the preferences for in-house services and the characteristics of households technology to produce in-house services determine the substitution patterns of the services and factor demands for inputs for the in-house services' production.

The Ogura low-lying basin located in the south of Kyoto has been urbanized rapidly in recent years.In this basin, several counter-measures against changes of flood runoff due to urbanization have been completed or are continueing, such as the construction of the Kumiyama Pump Station with a pump of 30m^3/s in 1973 and the channel improvements to the River Furu since 1971. Moreover, a pump of 30m^3/s was added at the Kumiyama Pump Station in 1987 and the Jouyou Pump Station with the drainage capacity of 10 m^3/s composed of two pumps of 5 m^3/s, was constructed at a point of the upper stream of the River Furu in 1990.In the previous paper, we discussed an optimum plan of drainage system from the viewpoint of minimum cost of costruction, on the basis of drainage conditions in 1960.This paper deals continually with an optimum plan of drainage system in future on the basis of the present condition of drainage system.As the result, it has been clarified that the optimum plan of drainage system in future is the combination of the improvement of channels and the increase of pump capacities at the existing pump stations, and that the construction of new drainage equipments become difficult because mainly of high price of lands.

The Ogura low-lying basin located in the south of Kyoto has been urbanizedrapidly in recent years. To cope with changes of flood runoff due to urbanization, the improvement of the River Furu was begun in 1971 and the Kumiyama PumpStation with a pump of 30 m3/s was built at the downstream end of the River Furuin 1973. Moreover, a pump of 30 m3/s was added in the Kumiyama Pump Station in1987 and a new pump station is being constructed at the upper stream of the RiverFuru.In addition to those counter-measures, several measures have been proposed inour previous papers. These measures, however, are derived from the viewpoint ofhydraulic engineering without of careful consideration on the economical aspect.This paper deals with an optimum plan of drainage systems from the viewpointof minimum cost of construction by using the technique of the DynamicProgramming. Furthermore, the effects of urbanization, change of the price of landand the flood plain compensation on the optimum plan of flood control areexamined to give useful information for future strategy in the optimum design ofdrainage systems.

In this paper, damage to buildings in Uki City, Kumamoto was investigated using information of building and damage included in the "Victims Master Database System", which was installed because of 2018 Kumamoto Earthquake. As a result, disaster resistant indexes of buildings like structural material and building year were extracted from a house tax roll included in the system. And outline of damage in large area was understood using information of victim's certificate and tax reduction in the system. However, it was a little difficult to combine the information of victim's certificate and house tax roll because their formats are different. The information which governments have is really helpful to investigate damage and expect risk due to disaster.

As the seismic isolation buildings become taller, the fatigue assessment of seismic isolation dampers against wind force have been necessary. In this paper shows fundamental studies on establishment of maintenance planning method in high rise seismic isolated building considering replacement of seismic isolation dampers.

Climate change impact has recently attracted one of the most public attention because of frequent water-related disasters. While very heavy rainfall observed in several stations, moderate rainfall lasted long time on the whole at torrential rain in wide area of Kinki region in 2013 due to Typhoon "Man-yi" and that around Kinu River basin which caused a dike breach and vast inundation of Joso city in 2015. However, the very heavy rain but short duration caused unprecedented debris flow disasters at just upstream areas in Hiroshima 2014 and northern Kyushu 2017 rainfall disasters which killed many people but slight damage in downstream of their trunk rivers. This paper focuses on characteristics of spatially averaged extreme precipitation in future using "Database for Policy Decision-Making for Future Climate Change" (d4PDF).

As the seismic isolation buildings become taller, the fatigue assessment of seismic isolation dampers against wind force have been necessary. In this paper shows fundamental studies on establishment of maintenance planning method in high rise seismic isolated building considering replacement of seismic isolation dampers.

This paper describes a prototype of a boat-type robot, which can automatically measure the mean velocity in river flows. The rotational speed of the screw propeller is proportional to the attacking velocity. Reliable laboratory experiments were conducted with the boat robot and electromagnetic velocimetry to obtain a calibration curve that connects the screw speed and mean current velocity. Two-dimensional navigation tests results in that the prototype moves smoothly to the target points and accurately measures the streamwise velocity profiles across the mainstream. Furthermore, the present robot was found to move successfully in a small natural river also, and we could evaluate the cross-sectional discharge.

This paper shows some results of intensive field observation carried out in the summer of 2016. The vertical profiles of currents and water temperature measured as well as wave and wind conditions, and salinity observations carried out at the observation tower of Shirahama Oceanographic Observatory. In the summer in 2016, one typhoon (TC16, MALAKAS) approached close to the observation site, and the high wave and strong wind conditions more than 40m/s captured during the observation. Under the high wave and strong wind condition, ADCP (Acoustic Doppler Current Profiler) measured high echo intensities for several hours, and this result indicates that strong mixing occurs. Water temperature variation at 30m deep has opposite phase to the fluctuation of salinity. This result means that low temperature and high salinity water approaches to the observation site. It is also found in water temperature distributions in November that some influences of the warm and cool water mass exist.