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Frank Engelund's theory of meander flow, published in 1974, marked a major advance, fromuniform bend flow to flow in truly meandering channels. The paper also contains several errors andomissions, some of which are by no means trivial. Both the achievements and the shortcomings of thework have acted to stimulate subsequent research, which is analyzed in this light. It is concludedthat a paper of sufficient elegance, that touches at the heart of the problem at hand, may includemany errors and still represent an achievement capable of stimulating the next generation of creativeresearch. The resolution of the errors flows in part from the structural elegance of the theory.

I entered the Coastal Engineering Lab, Department of Civil Engineering (Kyoto University), to carry out a graduation thesis in the 4th grade. I went on to the Master Course of Civil Engineering, and after getting Master's degree I was employed as a Research Associate at Kyoto University. Then I engaged in the research and education over 38 years. My research carrier was started with a sense of inferiority since I did not have enough knowledge of coastal engineering, mathematics, experimental techniques and so on. This paper describes my research activity and carrier after being a Research Associate, especially on what I thought about research life, distressing and pleasant things, memories of submitted papers and research achievement.

Observations with Ichinohe gravity variemeter of double bifilar suspension type havebeen made at 10 stations in Japan since several years ago for the purpose of detailed inves-tigation on time change of gravity. On the ether hand, a long period observation with As-kania gravimeter No. 111 was commenced at the International Reference Station of Gravityof Kyoto in Japan since July 1959 and is being continued up to the present time. Theseobservations will offer the significant information for investigating either micro-change ofgravity or relation between the gravity change and other geophysical phenomena, and willserve for research of earthquake prediction in the near future.In this paper, results obtained by the Askania gravimeter No. 111 during a period ofthe first one year from August 1959 to August 1960 are described somewhat in detail. Aftera detailed discussion, it was concluded that reliability of the value of tidal factor of gravitydetermined by one month's observation was within 3% of its value in the favourable obser-vational condition and suitable correction as in the present case.

The observations of earth tidal change of gravity in Japan are being continued upto the present time after IGY and IGC-1959. The data observed with the AskaniaGs-11 Gravimeter No. 111 during IGY were in detail treated and the definitive resultsof harmonic analysis were obtained.In this paper, the sensitivity of the Askania Gravimeter No. 111, the effect uponthe results of harmonic analysis caused by the difference of method of drift-elimina-tion, and the final results of harmonic analysis after the full correction are reported.Concerning the tidal factor of gravity, the effect of oceanic tide are in some detaildescribed, and it was found that the most reliable value of G(ml-3k/2+h) free fromthe influence of oceanic tides in Japan is 1.14. Moreover, the records of the greatChilean earthquake of May 22, 1960 simultaneously observed with two AskaniaGravimeters at Kyoto are shown.

昨年の秋Parisで開かれた国際重力委員会の会議において, 国際地球観測年(lntemationalGeophysi-calYear, LG.Y.と略す)の行事として, 重力部門では重力の潮汐変化の観測と南極地域の重力測定を実施することを決議した。いうまでもなく, わが国もこの企てに参加し, 南極地域の重力測定は建設省地理調査所がこれを担当し, 重力の潮汐変化は京都大学防災研究所が中心となり, 地理調査所がこれに協力して実行することになったのである。南極地域の重力測定班は目下南極へ向う途上にあり, 潮汐変化の方は現在国内十数ヵ所において観測を実施中であるため, 観測の全成果については観測年の終了後に一括して報告することとして, 本稿においては主として重力変化を観測することの目的と方法について述べ・あわせて観測開始からこんにちまで5ヵ月の間に得られた若干の成果について簡単に報告する。, As an international cooperative observation in the XIII WorkingGroup (Gravity) of CSAGI during the International Geophysical Year (1957~1958), study on change of gravity with time has been carried out by our Institute. Theitem on time change of gravity contains two branches, I.e. the periodic and non-periodic change of gravity. The former is the phenomenon caused by earth tidalchange, and the latter is related with the rapid or gradual change of gravity causedby change of state of material in the earth and earth's crust. For example, thechange of state of material in the earth's crust will be caused by earthquake-occurrence and volcanic eruption. In the present article, the aim of observation, observation instruments, observation stations are in some detail described, and theobservational results obtained are preliminarily reported.

国際地球観測年の事業として, 昨年7月1日からわれわれの研究室で始めた重力観測の目的, 観測器械および観測点の位置等については, すでに第一報において詳細に報告しているので, 本稿ではそれを省略し, 観測開始からこんにちまで17ケ月の間に得られた観測結果だけを, 第一報に掲載した分をも含めて, 一括して簡単に報告する。なお, 表中の記号の意味も, 第一報で説明しているので, ここでは省略する。, Observational results on the earth tidal change of gravity obtained at seven stationswith the Askania gravimeter are preliminarily reported, and the original data on gravitychange at the time of annular eclipse on April 19th, 1958 are reported in this paper.Concerning the station gravimeter of the double bifilar suspension type, an example of therecorded graph obtained at Kamigamo Geophysical Observatory is shown.

Recordable heavy rainfall hit and caused severe floods from the Kuma River in Hitoyoshi and Kuma regions in July, 2020 due to an active frontal rain system. This paper aims to show the flood impacts and mitigation effects of dams including proposing Kawabegawa dam. Additionally, we clarify challenges and issues in measures taken by core medical institutions against large-scale floods based on the results of interview with the core medical institution in Hitoyoshi and Kuma regions. The paper then discusses directions for effective flood countermeasures of core medical institutions in order to have more robust Business Continuity Plan (BCP) for large-scale flood disasters.

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.

This paper describes my life over 40 years after entry into Kyoto University. In the postgraduate course, my major field of study was about reinforced concrete structures. My career as teaching staff and a researcher started at National Institute of Technology, Akashi College in 1979. Then, I studied at University of Canterbury, New Zealand, as research associate from 1984 to 1987. I become a lecturer at University of Canterbury from 1990. In 1993, I was promoted to senior lecture and conferred tenure title. I came back to Japan in 1995 and joined Toyohashi University of Technology as associate professor. Then I moved to Kyoto University as Professor in 2001. The main part of this paper covers my contributions to research works on seismic design of reinforced concrete structures and laminated timber structures. Also contribution to the study about damages of buildings due to Tsunami .were described

The objective of this paper is to summarize the research activities of Research Center for Disaster Reduction Systems (the DRS), DPRI. The activities include research seminars inviting guest speakers from various fields such as disaster risk manager of the public sector, researchers, education sector and mass-media. Camping involving academic staffs as well as students is also a highlight of our activities. Research projects funded by the government as well as outside funding bodies are introduced. Finally, this paper also include the activity report of visiting professor at the DRS.

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.

The objective of this paper is to summarize the research activities of Research Center for Disaster Reduction Systems (the DRS), DPRI. The activities include research seminars inviting guest speakers from various fields such as disaster risk manager of the public sector, researchers, education sector and mass-media. Camping involving academic staffs as well as students is also a highlight of our activities. Research projects funded by the government as well as outside funding bodies are introduced.

The author was born in the northwest edge of Hyogo prefecture. His home was located near sea. The bitter and pleasant experience at seashore brought him up to work for national land management projects through Tottori university, Ministry of Construction, JICE, MLIT, ICHARM and finally DPRI, Kyoto university. The field of the work assigned to seacoast conservation, dam planning, river administration, river planning, local work office management, consulting MLIT, conducting training course, extreme analysis and climate change impact analysis. The tangent hyperbolic function appeared three times. The author introduced the function as if he was charmed by the function. This article is not classified into scientific paper but a kind of autobiography. He says to the young people 1) do by yourself when you lost, 2) have wide experience and wide spectrum of approach and 3) have a deep insight.

This paper summarizes the studies on three active faults, which the author has carried out through extensive observations and experiments. First, the Nojima fault is one part of the earthquake source fault of the 1995 Hyogo-ken Nanbu earthquake (M 7.3), and its healing process after the earthquake was studied by repeated water-injection experiments using three boreholes drilled through or close to the fault. We observed fault-zone trapped waves for injection-induced and background ultra-microearthquakes, and estimated deep structure of the Nojima fault. The second is the observation and analysis of typical fault-zone trapped waves in the subsurface survey tunnel excavated through the Mozumi-Sukenobe fault, one part of the Atotsugawa fault zone. The third is the Yamasaki fault zone. We estimated 3-D image of scattering strength around the fault by analyzing coda waves observed by dense temporary and routine seismic stations. We also studied generating properties of micro to small-scale earthquakes in heterogeneous source area., 本稿著者は，これまで行ってきた幾つかの活断層地域での研究について，2022年2月22日開催の令和3年度京都大学防災研究所研究発表講演会にて特別講演「活断層での観測・実験・研究とともに－野島断層・山崎断層・跡津川断層－」と題して講演を行った．本稿はその講演内容をベースとして，多少の補足等も加えて簡潔に取りまとめたものである．

伊勢湾台風による強風被害調査をはじめとして，過去50年以上にわたって京都大学防災研究所で行われた強風被害調査を概観し，強風被害の実態と変遷を調べるとともに，強風被害から明らかにされた教訓を，構造物の耐風設計との関連において検討した。また，竜巻などの小規模擾乱による強風被害と台風による強風被害を比較し，小規模擾乱における耐風対策について検討した。また，強風による人的被害を防ぐための心得を示した。, The investigations of damage induced by strong wind like typhoon, tornado and other local severe storms which have been carried out by the wind research group in DPRI since 1960's, are reviewed in the paper. A lot of lessons can be extracted from the investigation to improve wind resistant design of houses and buildings. Most vulnerable part of houses to wind is a roof and claddings. As more than half of damage of window and doors are induced by flying debris, it is very important to protect wind glasses from the flying debris by shutter or other measure e.g. use of laminated glass. Most of accident to peoples happens outdoor, so it is safe for us to stay in a house and a building when typhoon or tornado is approaching. Ten lessons and seven directions to be safe in strong wind are given in the paper.

For 40 years, I have been engaged in a research and education in Disaster Prevention Research Institute (DPRI) and Department of Civil and Earth Resources Engineering, Kyoto University. In the term, I moved to several research sections in DPRI. I would like to introduce what kind of research topics I engaged in and how the research topics were determined in these research sections. I will be happy if the paper can be of any help to your research life.

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.

The objective of this paper is to summarize the research activities of Research Center for Disaster Reduction Systems (the DRS), DPRI. The activities include research seminars inviting guest speakers from various fields such as disaster risk manager of the public sector, researchers, education sector and mass-media. Camping involving academic staffs as well as students is also a highlight of our activities. Research projects funded by the government as well as outside funding bodies are introduced.

Division of Technical Affairs, DPRI supported the development of a measurement system using a microcomputer board. The purpose of this development was to manufacture an easy-to-use device at low cost with multipoint observation in mind. This paper describes the outline of the equipment, the development process, the required cost, etc.

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．

本稿では，まず水資源コンフリクトの現況を世界と日本について記述し，次いでメタ認識としてのGES 環境システムと計画システムの輪廻を提案し，これらを前提としたコンフリクトマネジメント方法の体系化としてメタ適応的計画方法論を提案する。GES 環境システムでは，アジアと欧米のメタ認識の差異を論じ，計画システムの輪廻において「環境文化災害」という視点が重要であること，そして適応的計画方法論を構成する評価にあたる「費用便益分析」の限界ならびに「多基準分析」の流れを論じ，第3 者機関が介入するコンフリクトマネジメントを提案する．事例としては吉野川第十堰，長良川河口堰とガンジス川のファラッカ堰を取り上げる。, This paper shows inevitable fact we have to face up to water resources conflicts. Meteorological, hydrological, ecological and sociological problems with getting intertwined all together converge at water resources conflict problemin the end. For this reason, this paper firstly discusses the real situation of conflicts in domestic and international regionsand paradigm shift of water resources planning process based on environment capability considering social disparity forsustainability. Next, meta-logical methodology for conflict management introduced with recognition of GESenvironment, time varied circular system of water resources planning including environment disasters of collapse, pollution and culture, and adaptive water resources planning methodology of social conflict management forsurvivability. And then, some researches on conflict management are discussed.

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.

本報告では，38年間の研究活動を振り返り，行ってきた研究課題の中から，港内静穏度計算や多方向不規則波造波装置の開発，港湾・海岸構造物の信頼設計や個別要素法によるケーソンの挙動，リアルタイム津波予測に絞って，どのような時代背景や必要性の下にどのような考えで研究を行ってきたか，その考えの流れについて述べている．しかしながら，まだ十分に検討がなされていなく，これから実務に生かすための検討が必要なものについても記述している．また，研究を終えてから現在までの間に他の研究者によって得られた成果についても概述している．, The present paper describes the review of my research works which have been made for 38 years in the Port and Harbour Research Institute, former Ministry of Transport, and the Disaster Prevention Research Institute of Kyoto University. The paper gives the backgrounds and outlines of several selected research subjects on harbour tranquility, development of directional random wave generator, reliability design procedures for breakwaters, simulation of caisson behavior by DEM (Discrete Element Method), and real time prediction of tsunami. Some works like the harbor tranquility have been much developed after our works and some like the real time prediction need further more development for practical application.

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.

本研究では、防災研究所に蓄積されてきた研究成果の印刷物・映像情報を電子ファイル化し、Web上で高速検索可能なシステムの構築を目指している。平成16年度では、高速スキャナ、一括画像処理を取り入れた文献の電子ファイル化体制を確立し、昨年度に比べ作業効率を上昇させた。その結果、すべての年報のみならず、Bulletin、公開講座を含めた、約6万ページが、Web 上で公開可能である。また、文献以外の防災情報を高速検索できる新しい検索システムの構築案も示した。, A large amount of disaster prevention research base Printed Matters has stored since 1951 at the Disaster Prevention Research Institute (DPRI). The aim of assignment research subject of Division of Technical Affairs is that these base materials are widely exhibited to society, and can be used. However, the materials are not the one accumulated on the assumption of being able to use it on Web in the future. Thereby, it is difficult for us to pick up only necessary information of the materials. Accordingly, it is necessary to offer the comprehensible materials on the Internet to advance the disaster prevention study research. In this paper, we provide method of converting the materials of the DPRI into digitalized materials and construction of the high-speed system that can search the information of disaster prevention on the Web. In last year, we converted the 34-45 Annual papers to the Portable Document Format (PDF) files, which were exhibited on the DPRI Internet website. Moreover, we constructed the three kinds of search engines to search data of the DPRI Annual documents for users efficiently and conveniently. For this year, we show the faster-than-ever-before digitization of the disaster prevention research base materials of the DPRI including the DPRI Annuals. Additionally we show the construction of the search engine which can quickly search the materials on the Internet website.

本研究は，いかなる危機的状況においても，自治体が，効果的な危機管理対応を図るためのGIS を基盤とした危機管理システム構築を目指したものである．危機的状況が発生した場所でGIS を基盤とし様々な危機対応を支援することをCombat GIS と位置づけ， GIS を活用できる情報基盤をEnterprise GIS とした．本研究は，米国の先駆的な事例を調査し，日本の自治体におけるGIS の活用状況も把握し，日本社会に適した実践的なGIS の活用方策を提示したものである．, We are exposed to various kinds of Multi-hazards due to natural disasters, terrorist attacks and epidemic’s outbreak. In any of these crises, national and local governments have to implement emergency response and management effectively. Since Hanshin Awaji Greate Earthquake, GIS was recognized as powerful tool for disaster reduction and many GIS systems have been introduced by local governments for disaster management bureau. These systems are tools for estimating damage, and GIS is not still used well post-event consequence for management considered on disaster management cycle. In this paper, we introduced as a Combat GIS comprehensive emergency management system based on GIS. In other words, Combat GIS is a system that aims at utilizing GIS in the area affected emergency for local governments, and helping emergency response and management even if anywhere, anytime, any kinds of crisis occurs. CombatGIS makes use of integrated Enterprise GIS as information infrastructure for local government and compose of hardware, software, database, geospatial data, organization and people. In Japan, most local governments introduce GIS system as stand alone for routine work and GIS is not utilized common tool. In this paper, I show a strategy to construct Enterprise GIS and implement to utilize GIS for emergency response and management at some events at city of Uji, Kyoto Prefecture, Japan.

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.

This paper describes my research life over 42 years after graduation of Tokyo University of Science. Since entry into the postgraduate course of Tokyo Institute of Technology from 1978, my major research field has been Geomagnetism, in particular, Solid Earth Electromagnetism. My career as teaching staff and a researcher started at College of Humanities and Sciences, Nihon University in 1983 as a research associate and in 1991 as an assistant professor. Then I moved to the Disaster Prevention Research Institute, Kyoto University as an associate professor in 1992. The main part of this article is a review of my struggling in my field works on Solid Earth Electromagnetism. Intercommunication with research collaborators and students is also described.

This paper presents a formulation and a quantitative assessment of building fire risk to note a lesson learned from the Kyoto Animation office fire that was caused by arson in 2019 and resulted in 36 deaths; that is, the importance of designing staircases as fire compartments to protect occupants from smoke at an early stage of fire.

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.

The objective of this paper is to summarize the research activities of Research Center for Disaster Reduction Systems (the DRS), DPRI. The activities include research seminars inviting guest speakers from various fields such as disaster risk manager of the public sector, researchers, education sector and mass-media. Camping involving academic staffs as well as students is also a highlight of our activities. Research projects funded by the government as well as outside funding bodies are introduced.

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.