{"created":"2023-06-19T12:45:33.021981+00:00","id":5362,"links":{},"metadata":{"_buckets":{"deposit":"23a1cbe7-5ce1-408f-9c08-a7e67fcff38e"},"_deposit":{"created_by":3,"id":"5362","owners":[3],"pid":{"revision_id":0,"type":"depid","value":"5362"},"status":"published"},"_oai":{"id":"oai:tokyo-metro-u.repo.nii.ac.jp:00005362","sets":["521:613:616:763:1301"]},"author_link":["17886","17887"],"item_3_alternative_title_19":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"Flood Risk Assessment for the Cities on Valley Plains in Mountainous Areas"}]},"item_3_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1991-02","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"41","bibliographicPageEnd":"116","bibliographicPageStart":"103","bibliographic_titles":[{"bibliographic_title":"総合都市研究"}]}]},"item_3_creator_3":{"attribute_name":"著者別名","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"Mizutani, Takeshi"}],"nameIdentifiers":[{"nameIdentifier":"17887","nameIdentifierScheme":"WEKO"}]}]},"item_3_description_4":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"山地内や山麓の谷底低地に位置する都市市街地において生じた洪水災害(大量の死者や家屋損壊をもたらした災害の大部分はこれに含まれる)を分析して，家屋の全壊流失を引き起こす破壊力の大きい洪水(山地洪水)の発生条件を求めた。洪水流中にある物体の受ける力(洪水流力)は，単位時間に単位幅を通過する流水のもつ運動量，すなわち，流速の二乗と水深との積で与えられる。これは，単位幅流量と地表面勾配(S)の関数によって置き換えられ，さらに単位幅流量は降雨強度，流域面積(A)および谷底地面幅(W)の関数によって近似的に表される。災害規模は洪水流力の大きさ以外に，社会的条件の影響も受ける。1946年以降に生じた30の洪水災害事例の判別分析により，(P_<12>SA^<3/4>/W)K_1K_2＞110 の場合に，多数の(ほぼ50棟以上)の家屋全壊流失をもたらす山地洪水災害が発生しているという結果が得られた。ここにP_<12>は最大12時間雨量(流域平均値)である。K_1は時代係数で，1959年以前が1.45, 1960年以降が1.0，K_2は地域係数で，近畿以東の東日本が1.55，西日本が1.0である。この式の左辺は洪水災害危険度を表す総合的指標となる。上式を変形して，災害発生限界降雨強度を地形素因と社会的要因の関数で与える式が得られる。この限界降雨強度，さらにはその再現期間は，危険度を表す簡潔な指標となる。近年大きな災害を被っていない谷底内都市について，災害発生限界日雨量およびその再現期間を求めた。人的被害の規模を規定する要因には，その影響度の順に，時代，洪水流力，時刻，地域の要因があげられる。ただし1960年以降，人的被害度に低下の傾向は認められない。","subitem_description_type":"Abstract"},{"subitem_description":"Torrential floods which occur on steep narrow valley plains in mountainous areas just after the peak of a rainfall are the most destructive，because the velocity and the depth of the flow is large and the flow carries down a great amount of debris and wood produced by landslides due to the rainfall. Since this type of flood，which is named a torrential flood in this paper，has caused a large quantity of damage，especially casualties，it is necessary to conduct a vulnerability assessment. Supposing that the hydraulic force (F) of the flood flow is represented by the momentum of the flooding water which passes a given point in unit time and unit width，and using Manning's formula，it can be derived that F is represented by a power function of the water discharge per unit width and the surface slope (S) of the valley plain. The discharge of the flood flow which runs down the entire cross section of the valley plain can be approximated by a function of PA^<3/4>/W，where A(km^2) is the drainage area，W (km) is the average width of the valley plain and P(mm) is the average rainfall intensity in the drainage area. The scale of a flood damage is affected by social and human related factors in addition to the hydraulic force. Recent 30 instances of floods on valley plains show that torrential floods which destructed or swept more than 50 houses have occurred under the condition of (SP_<12>A^<3/4>/W)K_1_2＞110 where P_12 is the maximum 12-hour rainfall(mm). The coefficient K_1 is 1.55 for flood instances occurred in Eastern Japan，east of the Kinki District，and 1.0 for those in Western Japan. In the western part of Japan which is visited by a heavy rain frequently，the resistivity to flood hazards in respect of social and natural conditions is higher than in the eastern part of Japan. The coefficient K_2 is 1.45 for flood instances which occurred during 1946-1959，and 1.0 for those after 1960. In the period of about 15 years after the Second World War，the country was susceptible to flood hazards，resulting in frequent occurrence of big flood disasters. The coefficients were obtained by discriminant analysis using quantification method II. The value of the left side of the inequality (SP_12A^<3/4>/W)K_1K_2 can be used as a comprehensive index for identifying the risk of torrential floods on valley plains. It contains the factors of land properties，natural force and social conditions. When the value exceeds 110，a destructive torrential flood which world destroy or sweep a lot of houses development. From the inequality, P_<12>=110/(SA^<3/4>W)K_1K_2 is derived. This represents the threshold 12-hour rainfall intensity which induced destructive torrential floods as a function of topographic and social factors. The following relations P_<24>=125(SA^<3/4>/W)K_1K_2 P_3 =50/(SA^<3/4>/W)K_1K_2 are also derived，where P_<24> is threshold 24-hour rainfall intensity and P_3 is threshold 3-hour rainfall intensity which would induce destructive torrential floods on valley plains. The applicability of the relations is confirmed by the 30 instances of flood disasters. The threshold 24-hour rainfall intensity and the reccurrence interval of the rainfall intensity are obtained for the cities on valley plains which have not suffered from torrential floods recently. By discriminant analysis，it is derived that the factors affecting the scale of casualties due to the floods are period，hydraulic force，time and region in an decreasing order of the degree of influence.","subitem_description_type":"Abstract"}]},"item_3_description_40":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"subitem_description":"postprint","subitem_description_type":"Other"}]},"item_3_publisher_33":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"東京都立大学都市研究センター"}]},"item_3_source_id_10":{"attribute_name":"書誌レコードID","attribute_value_mlt":[{"subitem_source_identifier":"AN00134354","subitem_source_identifier_type":"NCID"}]},"item_3_source_id_8":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"03863506","subitem_source_identifier_type":"ISSN"}]},"item_3_version_type_16":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_970fb48d4fbd8a85","subitem_version_type":"VoR"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"水谷, 武司"}],"nameIdentifiers":[{}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2017-03-17"}],"displaytype":"detail","filename":"20024-041-009.pdf","filesize":[{"value":"605.5 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"20024-041-009.pdf","url":"https://tokyo-metro-u.repo.nii.ac.jp/record/5362/files/20024-041-009.pdf"},"version_id":"f82871c1-2814-4c74-a53e-b9798a071418"}]},"item_keyword":{"attribute_name":"キーワード","attribute_value_mlt":[{"subitem_subject":"Flood","subitem_subject_scheme":"Other"},{"subitem_subject":"Risk Index","subitem_subject_scheme":"Other"},{"subitem_subject":"Vulnerability Assessment","subitem_subject_scheme":"Other"},{"subitem_subject":"Threshold Rainfall Intensity","subitem_subject_scheme":"Other"},{"subitem_subject":"Valley Plain","subitem_subject_scheme":"Other"},{"subitem_subject":"Hydraulic Force","subitem_subject_scheme":"Other"},{"subitem_subject":"洪水","subitem_subject_scheme":"Other"},{"subitem_subject":"危険指標","subitem_subject_scheme":"Other"},{"subitem_subject":"危険度評価","subitem_subject_scheme":"Other"},{"subitem_subject":"限界降雨強度","subitem_subject_scheme":"Other"},{"subitem_subject":"谷底平野","subitem_subject_scheme":"Other"},{"subitem_subject":"流体力","subitem_subject_scheme":"Other"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"departmental bulletin paper","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"山地内都市の洪水災害危険度評価","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"山地内都市の洪水災害危険度評価"}]},"item_type_id":"3","owner":"3","path":["1301"],"pubdate":{"attribute_name":"公開日","attribute_value":"2017-03-31"},"publish_date":"2017-03-31","publish_status":"0","recid":"5362","relation_version_is_last":true,"title":["山地内都市の洪水災害危険度評価"],"weko_creator_id":"3","weko_shared_id":-1},"updated":"2023-06-19T17:20:47.248780+00:00"}