Updated on 2025/06/23
Slope deformation
Mountain river
GIS
Lightning Geomorphology
Geoarchaeology
Tephrochronology
Geospatial Information Science
Radiocarbon Dating
cosmogenic nuclide analysis
Quaternary geology
Anthropocene
Disaster Risk Cognition and Reduction
Critical zone
Geomorphology
Physical geography
Humanities & Social Sciences / Geography / Physical Geography
Natural Science / Human geosciences / Geomorphology
Niigata University Faculty of Humanities Assistant Professor
2025.4
Country：Japan
Niigata University Institute for Research Administration
2025.4
Country：Japan
Meiji University School of Arts and Letters Lecturer (part-time)
2024.4 - 2025.3
Chuo University The Institute of Science and Engineering JSPS Research Fellow PD
2022.10 - 2025.3
Kyoto University Disaster Prevention Research Institute JSPS Research Fellow DC1
2019.4 - 2022.9
Niigata University Department of Humanities, Faculty of Humanities Assistant Professor
2025.4
Niigata University Institute of Humanities and Social Sciences, Academic Assembly Assistant Professor
2025.4
Kyoto University Graduate school of Science Division of Earth and Planetary Science
2019.4 - 2022.9
Country： Japan
Kyoto University Graduate School of Science Division of Earth and Planetary Science
2017.4 - 2019.3
Country： Japan
Senshu University School of Letters Department of Geography
2013.4 - 2017.3
Country： Japan
Iwaki High School, Fukushima
2010.4 - 2013.3
Country： Japan
Japan Association for Quaternary Research
2020
American Geophysical Union
2019
JAPANESE GEOMORPHOLOGICAL UNION
2017
THE ASSOCIATION OF JAPANESE GEOGRAPHERS
2016
JAPAN GEOSCIENCE UNION
2015
Geographic Information System Association
2025
Tokyo Geographical Society
2023
Japanese Society for Active Fault Studies
2022
国土地理院 全国活断層帯情報整備検討委員会
2025.4
Committee type：Government
国土地理院 全国活断層帯情報整備検討委員会（調査協力者）
2023.4 - 2025.3
Late Pleistocene tephras found in the vicinity of Mt. Kushigata, the Koma Mountains in central Japan Reviewed
Ryoga Ohta, Tatsuki Watanabe, Yoshihiko Kariya
The Quaternary Research (Daiyonki-Kenkyu) 64 ( 1 ) 1 - 12 2024.10
Transient Response and Adjustment Timescales of Channel Width and Angle of Valley-Side Slopes to Accelerated Incision Reviewed
Naoya O. Takahashi, J. Bruce H. Shyu, Shinji Toda, Yuki Matsushi, Ryoga J. Ohta, Hiroyuki Matsuzaki
2023.6
Use of terrestrial cosmogenic 10Be to quantify anthropogenic sediment yield from mountainous watersheds: Application in reconstructing environmental change in the Tanakami Mountains, central Japan Reviewed
Ryoga Ohta, Yuki Matsushi, Hiroyuki Matsuzaki
Geomorphology 405 ( 108201 ) 1 - 17 2022.3
Quantification and reconstruction of anthropogenically-accelerated hillslope erosion: Changes in soil sustainability and transition of watershed environment as responses to the longstanding consumption of forest resources Reviewed
Ryoga OHTA
Kyoto University 2022.9
1:25,000活断層図「柳ヶ瀬・関ヶ原断層帯及び湖北山地断層帯とその周辺」
金田平太郎, 石村大輔, 堤浩之, 中田高, 太田凌嘉
国土地理院 2024.10
Three-stage evolution of particle shape in headwater streams
Naoya Ono Takahashi, Daisuke Ishimura, Keitaro Yamada, Ryoga J. Ohta, Yuki Arai, Yuki Yamane
EGUsphere 2025.3
Shape of natural and manually crushed particles collected from a headwater stream in Tsugaru, Japan
Naoya Takahashi, Daisuke Ishimura, Keitaro Yamada, Ryoga Ohta, Yuki Arai, Yuki Yamane
2025.2
Late Pleistocene tephras and pollen fossils found in the vicinity of Mt. Kushigata, the Koma Mountains in central Japan Reviewed
Ohta, Ryoga, Watanabe, Tatsuki, Kariya, Yoshihiko
Japan Association for Quaternary Research. Dataset. 2025.2
過度な森林資源の収奪を受けた山地流域の不可逆的環境変化のモデル化：いわゆるハゲ山を捉え直す
太田凌嘉
GIS NEXT 71 69 2020.4
Report on participation in the 2017 International Summer School on Rockslides and Related Phenomena in the Kokomeren River Valley, Kyrgyzstan Reviewed
Ryoga OHTA, Yoshihiko KARIYA
J. of the Jpn. Landslide Soc. 55 ( 2 ) 92 - 95 2018.3
Variability of hillslope morphology in response to tectonic forcing: an example from Natsui-gawa watershed in the Abukuma massif, Fukushima Prefecture, Japan
Ryoga Ohta
The General Meeting of the Association of Japanese Geographers Spring 2025 2025.3
Three-stage evolution of particle shape in the headwaters
Naoya TAKAHASHI, Daisuke ISHIMURA, Keitaro YAMADA, Ryoga OHTA, Yuki Arai, Yuki Yamane
The General Meeting of the Association of Japanese Geographers Spring 2025 2025.3
Differences in the propagation of base-level changes on watershed denudation: an example from the Abukuma massif, Fukushima Prefecture, Japan
Ryoga J. OHTA
The Japanese Geomorphological Union Annual Meeting 2024 2024.11
Sediment discharge and its determinants in the burnt area of wildfire: The case of Osaki peninsula, Iwate
Hotaka Sato, Naoya Takahashi, Ryoga Ohta
JpGU Meeting 2024 2024.5
Development of fluvial terraces and moutainous hillslopes as part of the landscape evolution in the Koma Mountains, central Japan
Ryoga Ohta, Yoshimasa Ota
JpGU Meeting 2024 2024.5
Contrasting grain size evolution in headwaters controlled by rock strength and provenance
Naoya Takahashi, Daisuke Ishimura, Ryoga Ohta, Yuki Arai, Yuki Yamane
JpGU Meeting 2024 2024.5
Use of terrestrial cosmogenic 10Be for quantification and reconstruction of anthropogenically-accelerated hillslope erosion: as responses to the longstanding consumption of forest resources
Ryoga Ohta, Yuki Matsushi, Hiroyuki Matsuzaki
The 24th AMS Symposium 2024.3
Contrasting grain shape evolution in headwaters controlled by rock strength and provenance
Naoya TAKAHASHI, Daisuke ISHIMURA, Ryoga OHTA, Yuki Arai, Yuki Yamane
The General Meeting of the Association of Japanese Geographers, Spring 2024 2024.3
Slip-rate estimation of an active fault by using depth profiling of terrestrial cosmogenic 10Be: a case study on a middle terrace surface at Nogo along the Neodani fault, central Japan
Yuya Ogura, Heitaro Kaneda, Ryoga Ohta, Yuki Matsushi, Hiroyuki Matsuzaki
Japanese Society for Active Fault Studies Fall Meeting 2023 2023.11
History of mass movements in a tectonically active mountainous watershed: A case study in Mt. Kushigata, Koma Moutains, central Japan
Ryoga Ohta, Tatsuki Watanabe
Japanese Society for Active Fault Studies Fall meeting 2023 2023.11
Change in sustainability of hillslope soil and transition in watershed environment as responses to the longstanding exploitation: modelling in the Tanakami Mountains, central Japan
Ryoga Ohta, Yuki Matsushi
The General Meeting of the Association of Japanese Geographers Spring 2023 2023.3
Reconstructing anthropogenic environmental change in a mountain watershed by terrestrial cosmogenic 10Be: application of the new usage in the Tanakami Mountains, central Japan Invited
Ryoga Ohta, Yuki Matsushi, Hiroyuki Matsuzaki
Japan Geoscience Union Meeting 2022 2022.6
Reconstructing human-induced acceleration of hillslope denudation in granite watersheds using cosmogenic nuclide: modeling in the Tanakami Mountains, central Japan
Ryoga OHTA, Yuki MATSUSHI, Hiroyuki MATSUZAKI
DPRI Annual meeting 2021.2
Transition of soil sustainability in granite watersheds through artificial deforestation: quantifying acceleration of hillslope erosion in the Tanakami Mountains, central Japan
Ryoga OHTA, Yuki MATSUSHI, Hiroyuki MATSUZAKI
JpGU-AGU Joint Meeting 2020 2020.7
Quantifying human-induced acceleration of hillslope denudation in granite watersheds: impacts of deforestation on soil coverage in the Tanakami Mountains, central Japan
Ryoga OHTA, Yuki MATSUSHI, Hiroyuki MATSUZAKI
2020.2
人為的な森林の消失に伴う流域の斜面安定性の遷移：樹木根系の効果を考慮した土層発達モデリング
太田凌嘉
一般社団法人建設コンサルタンツ協会近畿支部 第52回研究発表会 2019.10
活断層末端の活火山地域における大規模斜面崩壊の発生予測に関する研究―1858年（安政5年）立山, 鳶崩れを例としてー
金田平太郎, 佐々木夏来, 石村大輔, 福井幸太郎, 大森貴之, 松四雄騎, 土井一生, 加納靖之, 大邑潤三, 飯島 駿, 太田凌嘉, 小倉祐弥, 渡辺 樹
「災害の軽減に貢献するための地震火山観測研究計画（第２次）」令和４年度成果報告シンポジウム 2023.3
Reconstructing the transition of hillslope denudation in granite watersheds using cosmogenic nuclides: quantifying the anthropogenic impacts on soil coverage in the Tanakami Mountains, central Japan
Ryoga Ohta, Yuki Matsushi, Hiroyuki Matsuzaki
Japan Geoscience Union Meeting 2021 2021.6
Adjustment timescales of channel width and hillslope angle to accelerated uplift: Insights into a basin-scale steady state
Naoya Takahashi, J Bruce H Shyu, Yuki Matsushi, Ryoga Ohta, Shinji Toda
Japan Geoscience Union Meeting 2021 2021.6
Quantifying anthropogenic acceleration of hillslope denudation in granite watersheds: impacts of deforestation on soil coverage in the Tanakami Mountains, central Japan International conference
Ryoga OHTA, Yuki MATSUSHI, Hiroyuki MATSUZAKI
American Geophysical Union Fall Meeting 2019.12
Quantifying anthropogenic acceleration of hillslope destabilization by deforestation: modeling soil development incorporating tree-root reinforcement in the Tanakami Mountains, central Japan
Ryoga OHTA, Yuki MATSUSHI, Hiroyuki MATSUZAKI
2019 JGU 40th Anniversary Meeting 2019.11
Quantification of anthropogenic denudation caused by deforestation in mountainous watersheds: cases in Tanakami Mountains, central Japan
Ryoga OHTA, Yuki MATSUSHI, Ken'ichirou KOSUGI, Hiroyuki MATSUZAKI
Proceedings of the General Meeting of the Association of Japanese Geographers 2019.3
Quantitative modeling of anthropogenic irreversible transition in denudation processes and hillslope stability on mountainous watersheds: tree root reinforcement for soil development on hillslopes
Ryoga OHTA, Yuki MATSUSHI
2019.2
Reconstructing long term transition of denudation rates using a terrestrial cosmogenic nuclide in fluvial sediment in granite watersheds devastated by significant human impact
Ryoga OHTA, Yuki MATSUSHI, Hiroyuki MATSUZAKI
JpGU2018 2018.5
Reconstructing long term sediment yield from granite watersheds affected by significant human impact
Ryoga OHTA, Yuki MATSUSHI
2018.2
History of mass movements and paleolake formation revealed by depression-filling sediment records in a tectonically active mountainous area: a case study in Mt. Kushigata, Koma Range, central Japan International conference
Ryoga OHTA, Yoshihiko KARIYA, Yuki MATSUSHI
4th Slope Tectonics Conference 2017 2017.10
Development of paleolakes related to landslide activities in the late Pleistocene epoch on the eastern foot of Mount Kushigata, the Koma Mountains in central Japan International conference
Ryoga OHTA, Yoshihiko KARIYA
JpGU－AGU Joint Meeting 2017 2017.5
Late Pleistocene paleolakes formed on landslide blocks in the eastern foot of Mount Kushigata, the Koma Mountains in central Japan
Ryoga OHTA, Yoshihiko KARIYA
Proceedings of the General Meeting of the Association of Japanese Geographers 2017.3
Late Pleistocene paleolakes related to landslide activities on the eastern foot of Mount Kushigata, the Koma Mountains, central Japan
Ryoga OHTA, Yoshihiko KARIYA
Proceedings of the General Meeting of the Association of Japanese Geographers 2016.9
Late Pleistocene paleolakes formed by landslide activities on the eastern foot of Mt. Kushigata, the Koma Mountains, central Japan
Ryoga OHTA, Yoshihiko KARIYA
JpGU2016 2016.5
宇宙線生成核種10Beを用いた深度断面法による活断層の平均変位速度推定 ―根尾谷断層，能郷地区中位段丘面を例として―
2023.11
Deciphering the history of earthquake induced sediment yield by cosmogenic nuclides: Integration of tectonic and process geomorphology
Grant number：22J01231
2022 - 2025
System name：Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows
Research category：Grant-in-Aid for JSPS Fellows
Awarding organization：Japan Society for the Promotion of Science
Authorship：Principal investigator
Grant amount：\4420000 （ Direct Cost: \3400000 、 Indirect Cost：\1020000 ）
山地流域における水文・地形プロセスのモデリングに基づく土砂移動現象の発生場・降雨閾値・生産土砂量の定量的評価
2020 - 2022
Awarding organization：Ministry of Land, Infrastructure, Transport and Tourism
Yuki Matsushi, Taro Uchida, Yasuhiro Shuin, Yasuto Hirata Hiroyuki, Matsuzaki Ryoga Ohta
Authorship：Coinvestigator(s)
Modelling of irreversible environmental change in mountain watersheds caused by excessive expropriation of forest resources
Grant number：19J22493
2019.4 - 2022.3
System name：Grants-in-Aid for Scientific Research Grant-in-Aid for JSPS Fellows
Research category：Grant-in-Aid for JSPS Fellows
Awarding organization：Japan Society for the Promotion of Science
長期的かつ過度な人為インパクトを受けた山地における土層の生成と流出に関する調査
2018.6 - 2019.3
System name：平成30年度深田野外調査助成
Awarding organization：深田地質研究所
太田 凌嘉
Authorship：Principal investigator Grant type：Competitive
Study of deep water storages of watersheds under naturally forested and deforested conditions
2017 - 2018
System name：Grant from Research Unit for Development of Global Sustainability, Kyoto University
Awarding organization：Research Unit for Development of Global Sustainability, Kyoto University
Cristobal Padilla Yuki Matsushi Ryoga Ohta
Authorship：Coinvestigator(s)
Soil sustainability on hillslopes for forest persistence: quantification by geomorphic approach
2017 - 2018
System name：Grant from the Research Unit for Development of Global 651 Sustainability, Kyoto University
Awarding organization：Research Unit for Development of Global Sustainability, Kyoto University
Yuki Matsushi Cristobal Padilla, Ryoga Ohta
Authorship：Coinvestigator(s)
中学校教諭一種免許状（社会）取得
高等学校教諭一種免許状（地理歴史）取得
日本地理学会認定資格 地域調査士 取得
日本防災士機構認定資格 防災士 取得
測量士補
GIS学術士
地理学実習B
地理学実習D
社会文化学入門A
社会・地域文化学入門
Frontier for Humanity
地理学実習C
地理学実習A
Topics in Physical Geography II (Critical Zone Science in the Anthropocene)
Physical geography
子どもウィークリー「知りたい好奇心」 Newspaper, magazine
山梨日日新聞 山梨日日新聞・朝刊 2019.2
東北発☆未来塾 TV or radio program
NHK 2015.3
