Watershed Hydrology Group

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Apr 4, 2025: A new M1 student!

Mr. Asim Hussain, the MEXT scholarship student from Pakistan to our university, entered our graduate course today!!

Welcome to our lab!!

Mar 8, 2025: Published!

We are pleased to announce that Mr. Bari's second paper below was published on Hydrological Research Letters.

Bari SH, Tateno M, Yokoo Y, Leong C. (2025) Dynamics, particle size distribution and mineral composition of suspended sediment transport in the Abukuma River estuary, Hydrological Research Letters, 19(1), 51-57. DOI: 10.3178/hrl.24-00028.

Mr. Bari is now working on his third paper for this PhD dissertation. 

Oct 12, 2024: Outdoor BBQ/Imoni party!

We had a welcome BBQ and Imoni party on Oct 12 to  welcome our 5 new members and to interact with our OBs/OGs. This year, we had two OBs. One of them came from Nara prefecture all the way by highway bus and the other reported  he got married.

It was my pleasure to  talk with them and I hope we can see you all next year again!! 

Oct 1, 2024: New members joined our group!!

We are pleased to announce that 4 undergraduate students joined our group from October.

• Souta ISHII

• Yuya ISHII

• Haruki YATABE

• Takumu YOSHIDA

Sep 30, 2024: Mr. Asim Hussain joined our group!!

Finally, Mr. Asim Hussain arrived at Fukushima University to be a member of our group!! He is a new MEXT scholarship student from Pakistan.

We appreciate for the kind support from our international center to realize Asim's study in Fukushima University.

We want to learn about Pakistan and we hope we can soon know each other from today.

July 5, 2024: Mr. Asim Hussain will join our group!!

Mr. Asim Hussain was approved by the MEXT as a 2024 MEXT scholarship student in our laboratory with the strong supports by the officers of the international center in Fukushima University.

Congratulations to Asim!! We are looking forward to meeting you!!

July 5, 2024: Mr. Asim Hussain will join our group!!

Mr. Asim Hussain was approved by the MEXT as a 2024 MEXT scholarship student in our laboratory with the strong supports by the officers of the international center in Fukushima University.

Congratulations to Asim!! We are looking forward to meeting you!!

May 28, 2024: Mr. Bari gave a presentation at JpGU 2024 meeting

Mr. Bari, our PhD student, gave a presentation at JpGU 2024 meeting to have feedback to his recent achievements.

Bari SH, Tateno M, Yokoo Y.: Estimating sand, silt and clay transport at the Abukuma River estuary for a comprehensive understanding of suspended sediment dynamics from the watershed to the Pacific Ocean, ACG43-P06, Japan Geoscience Union Meeting 2024, Makuhari, Chiba, May 28, 2024.

Apr 13, 2024: Just published!!

Mr. Bari's paper has just published on Hydrolgical Research Letters.

Bari SH, Yokoo Y, Leong C. (2024) A brief review of recent global trends in suspended sediment estimation studies. Hydrological Research Letters, 18, 51-57. DOI: 10.3178/hrl.18.51.

We appreciate for the efforts and supports by the reviewers, editors, and the publishers in charge for our paper.

Apr 1, 2024: A new member!

Ms. Noor-E-Ashmaul Husna joined our laboratory as a visiting researcher to our laboratory as of April 1, 2024.

Welcome to our laboratory, Ms. Husna!!

Mar 7, 2024: Just Accepted!!

Mr. Bari's paper has just accepted for publication on Hydrolgical Research Letters.

Bari SH, Yokoo Y, Leong C. (2024) A brief review of recent global trends in suspended sediment estimation studies. Hydrological Research Letters (Accepted).  

We appreciate for the efforts and supports by the reviewers, editors, and the publishers in charge for our paper.

Dec 8, 2023: Finally published!!

The Ms. Tateno's manuscript has just published on Hydrolgical Research Letters.

Tateno M, Yokoo Y, Leong C. (2023) Estimating suspended sediment discharge and its annual mass balance in the Japanese first-class watersheds, Hydrological Research Letters, 17(4), 92-97. DOI: 10.3178/hrl.17.92.

We appreciate for the efforts and supports by the reviewers, editors, and the publishers in charge for our paper.

Sep 23, 2023: Finally accepted!!

The Ms. Tateno's manuscript was accepted for publication in Hydrolgical Research Letters.

The first submission result was a rejection, but after about a year of work to correct the problems, her paper was successfully accepted. During this period, she redid the calculations many times. She seemed discouraged many times, but I guess her continuous effort and her energy made it accepted.

The reviewers and editors gave me very detailed and accurate comments. Thanks to them, the content of the paper has been greatly improved. We would like to express our sincere thanks to them.

Tateno M, Yokoo Y, Leong C. 2023. Estimating suspended sediment discharge and its annual mass balance in the Japanese first-class watersheds, Hydrological Research Letters (accepted).

June 6, 2023: New Research Associate

Ms. Eiko Kanno joined our lab. as a research associate.

We are happy to have her in our group!

Apr 1, 2023: A New Ph.D student

Mr. Sheikh Hefzul Bari officially joined our Ph.D. program in Fukusuhima Univerisyt to pursue his research on watershed-scale sediment dynamics.

We are looking forward to enjoying a new adventure with him!

Apr 1, 2023: A New Visiting Research Fellow

Dr. Chris Leong officially joined our laboratory as a visiting research fellow to our Faculty of Symbiotic Systems Science, Fukushima University.

He is one of our OBs/OGs and he would strongly support our activity.

May 24, 2022: Farewell  to Dr. Chris Leong

It is glad to announce that Dr. Chris Leong will soon start to work at the Research Institute for Humanity and Nature as of June 1, 2022. It means he must leave Fukushima university by May 31, 2022. Upon this occasion, we had a small farewell gathering after our weekly lab meeting on May 24 with the supports by students led by Sheikh and Ms. Tateno.

Chris joined our group in October 2014 as a MEXT scholarship student and he entered our Master's program in April 2015. Then he continued his research in our Doctoral program in April 2017 to obtain his Ph.D in March 2020. Since April 2020, he have been worked as a post-doctoral research fellow for our project by today. His distinguished achievements can be confirmed in his 6 papers and 4 awards. 

It is sad to leave him from our group, but we would like to congratulate his departure toward more glorious future.

Good luck!!

Apr 18, 2022: Mr. Sheikh Hefzul Bari arrived

We are glad to inform that Mr. Sheikh Hefzul Bari had arrived at Fukushima on April 16 and started to join our group on April 18. He was selected a MEXT scholarship student to our group in 2021 but we have to wait a chance to travel from Japan to Bangladesh under the global spread of  the COVID-19 and difficult Japanese boarder controls.

We should experience a completely different culture and we would like to support him so that we can be familiar with his life in Fukushima. 

Mar 28, 2022: Chris's paper was accepted for publication!!   

We are glad to inform that a Chris's latest work was accepted for publication by Hydrological Processes. I guess this is a Chris's masterpiece by today and we hope this paper can contribute to the future of rainfall-runoff modeling and flow duration curve studies. Congratulations to Chris!!

We would like to thank Prof. Botter who handled our paper as the editor in charge and two anonymous reviewers who provided continuous efforts for improving and finalizing our paper.

Leong, C. and Yokoo, Y. (2022) A multiple hydrograph separation technique for identifying hydrological model structures and an interpretation of dominant process controls on flow duration curves, Hydrological Processes, 36( 4), e14569. DOI: 10.1002/hyp.14569.

Oct 1, 2021: new members!

We are glad to have four new undergraduate students as below:

• Eisuke ARAKI

• Ryosuke OKUZAKI

• Kazuma SAITO

• Katsuya TASAKI

Welcome to our laboratory!!

Sep. 20, 2021: A review paper was accepted for publication

We are pleased to announce that a review paper by Dr. Chris Leong was accepted for publication today. This paper summarizes the recent progress in the flow curves studies based on the literature review part of his doctoral dissertation, which is a groundbreaking achievement for our laboratory and we are very happy to see Chris's efforts come to fruition.

Leong, C., Yokoo, Y. (2021) A step toward global scale applicability and transferability of flow duration curve studies: A flow duration curve review (2000-2020), Journal of Hydrology, 603, B, 126984. DOI: 10.1016/j.jhydrol.2021.126984.

Sep. 10, 2021: Dr. Chris Leong gave a talk

Dr. Chris Leong gave a talk today as below!!

Leong, C., Yokoo, Y. : Application of flexible model structures to interpret dominant process controls on flow duration curves,  International Conference on Sustainable Water Resources Management- Global Challenges and Opportunity -, Committee on Global Environment, JSCE, On-line, Sep. 10, 2021.

Congratulations to Dr. Chris Leong

We are pleased to announce that Dr. Chris Leong, our post-doctoral research fellow, received the 2021 Construction Engineering Research Promotion Award from the Japan Society for the Promotion of Construction Engineering Research. The certificate will be sent by postal mail and the prize money for his research will be transferred to the bank account of our university, because the ceremony can not be held under the current COVID-19 situation.

Congratulations to Chris!!

Call for applicants: MEXT scholarship students (university recommendation)

We are now open for applicants of 2021 MEXT scholarship students (university recommendation by Fukushima University). If you want to apply for the scholarship from our research group at Fukushima university, please contact to us by the end of January 2021.

More information is available at:

https://sites.google.com/sss.fukushima-u.ac.jp/whgfu-e/menu/mext-scholarship

Two awards from the Japan Society of Hydrology and Water Resources to us!!

We received two awards simultaneously from the Japan Society of Hydrology and Water Resources (JSHWR) in the annual meeting of JSHWR 2020!! These are extraordinary achievements in the history of our research group.

Young Author Excellent Article Award

The "Young Author Excellent Article Award" was presented to Dr. Chris Leong, a  post-doctoral researcher in our group for his achievements listed below:

• Leong, C., Yokoo, Y. (2019) An interpretation of the relationship between dominant rainfall-runoff processes and the shape of flow duration curve by using data-based modeling approach, Hydrological Research Letters, 13, 62-68. DOI: 10.3178/hrl.13.62.

• Leong, C., Yokoo, Y. (2019) Estimating flow duration curves in perennial and ephemeral catchments by using a disaggregated approach, Hydrological Research Letters, 13, 14-19. DOI: 10.3178/hrl.13.14.

• Leong, C., Yokoo, Y. (2017) Estimating flow duration curve in the humid tropics: a disaggregation approach in Hawaiian watersheds, Hydrological Research Letters, 11, 175-180. DOI: 10.3178/hrl.11.175.

Excellent Article Award

The "Excellent Article Award" was presented to Yoshiyuki Yokoo, together with Dr. Asano (The University of Tokyo), Dr. Uchida (University of Tsukuba), Prof. Katsuyama (Kyoto Prefectural University), Prof. Gomi (Tokyo University of Agriculture and Technology), Dr. Hiraoka (Public Works Research Institute), Dr. Mizugaki (Public Works Research Institute) for the consecutive papers listed below:

• Yokoo, Y., Niwa, S., Uchida, T., Hiraoka, M., Katsuyama, M., Gomi, T., Mizugaki, S., Asano, Y. (2018) Effects of spatial scales on runoff / sediment transport in mountain catchments (3) - review for the treatments of numerical models, Journal of Japan Society of Hydrology and Water Resources, 31(4), 232-244. (In Japanese with English abstract)

• Asano, Y., Uchida, T., Katsuyama, M., Hiraoka, M., Mizugaki, S., Gomi, T., Niwa, S., Yokoo., Y. (2018) Effects of spatial scales on runoff / sediment transport in mountain catchments (2) - results from intensively studied catchments, Journal of Japan Society of Hydrology and Water Resources, 31(4), 232-244. (In Japanese with English abstract)

• Asano, Y., Uchida, T., Gomi, T., Mizugaki, S., Hiraoka, M., Katsuyama, M., Niwa, S., Yokoo., Y. (2018) Effects of spatial scales on runoff / sediment transport in mountain catchments (1) - a review of field observations on catchment area and properties, Journal of Japan Society of Hydrology and Water Resources, 31(4), 219-231. (In Japanese with English abstract)

We thank all the reviewers and editors who contributed to improve our papers in addition to the recommenders and examiners for our papers. With these memorial achievements, we would try to further improve our research activities toward tasteful sciences by "thinking different and making wonders".

Five on-line presentations at JpGU-AGU Joint Meeting 2020

JpGU-AGU Joint meeting 2020 was held as the first on-line meeting this year, because of the COVID-19. In this meeting, Dr. Asano and I organized a session entitled as below successfully with the helps by our colleagues and speakers.

[A-HW33] Prediction of water and sediment dynamics from small to large scales

From our research group, there were 5 presentations listed below and Mr. Sato, our M1 student served excellent oral presentation after careful preparations.

1. Asano, Y., Uchida, T., Gomi, T., Mizugaki, S., Hiraoka, M., Katsuyama, M., Niwa, S., Yokoo, Y.: Effect of spatial scales on runoff / sediment transport in mountain catchments, A-HW33-01, JpGU-AGU Joint Meeting 2020, On-line, July 14, 2020.

2. Uchida, T., Asano, Y., Mizugaki, S., Yokoo, Y., Hiraoka, M., Gomi, T., Niwa, S., Katsuyama, M.: Towards improving predictivity of runoff and sediment transport for mountainous catchments through measurement of spatial patterns of hydrological behaviors, A-HW33-05, JpGU-AGU Joint Meeting 2020, On-line, July 14, 2020.

3. Leong, C., Yokoo, Y.: Understanding catchment processes and scale effect on catchment flows, A-HW33-10, JpGU-AGU Joint Meeting 2020, On-line, July 14, 2020.

4. Yokoo, Y., Sakairi, T., Leong, C.: Applying a data-based rainfall runoff modeling approach to interpret the mechanisms of decreasing spatial variability of subcatchment-specific discharge with increasing subcatchment area, A-HW33-11, JpGU-AGU Joint Meeting 2020, On-line, July 14, 2020.

5. Satou, H., Yokoo, Y., Leong, C.: Dependency of watershed-scale rainwater storage on watershed-area at the occurrence times of slope failures: a preliminary investigation in Japan, A-HW33-P03, JpGU-AGU Joint Meeting 2020, On-line, July 14, 2020.

Welcome Dr. Chris Leong

We are glad to announce that Dr. Chris Leong, our former Ph.D. student joined our research group on April 1, 2020.

He is working for our research projects now.

Chris Leong, our PhD student, received the FY2019 "President Award"!! 

We are glad to announce Mr. Chris Leong, our PhD student as a MEXT scholarship student from the Republic of Fiji, received the President Award of the fiscal year 2019 from Prof. Katsumi Nakai, the president of Fukushima University for his continuous efforts and the academic achievements on March 16, 2020.

The award wen to him for his grades in studies and his research achievements.

Chris is scheduled to receive a Ph.D on March 25, 2020 and he is going to be the first Ph.D from our group.

Congratulations to Chris!!

Call for applicants: MEXT scholarship students (university recommendation)

We are now open for applicants of 2020 MEXT scholarship students (university recommendation). If you want to apply for the scholarship from our research group at Fukushima university, please contact to us by the end of January 2020.

More information is available at: 

https://sites.google.com/sss.fukushima-u.ac.jp/whgfu-e/menu/mext-scholarship

New publication!!

The latest paper by Chris has just published on "Hydrological Research Letters" again.

Leong, C., Yokoo, Y. (2019) An interpretation of the relationship between dominant rainfall-runoff processes and the shape of flow duration curve by using data-based modeling approach, Hydrological Research Letters, 13, 62-68. DOI: 10.3178/hrl.13.62

This paper clearly interpreted the shapes of flow duration curves under different climate conditions in terms of the data-based modeling approach of dominant rainfall-runoff mechanisms. It seems this is the best paper ever written by Chris and I hope it can be shared globally.

Congratulations to Chris!!

Chris's paper was accepted for publication in "Hydrological Research Letters" again.

Leong, C., Yokoo, Y. (2019) An interpretation of the relationship between dominant rainfall-runoff processes and the shape of flow duration curve by using data-based modeling approach, Hydrological Research Letters, 13 (accepted).

We sincerely thank the anonymous reviewers and editors in charge for this paper.

August 6, 2019 AOGS2019@Singapore

We made the following presentation in the AOGS 2019 meeting in Singapore.

Udo, K., Takeda, Y., Yokoo, Y: Sediment Balance from Mountains to Coasts in Japan: Huge Impact of Past River Mining, HS02-A001 (Invited), Asia Oceania Geosciences Society 16th Annual Meeting (AOGS 2019), Singapore, July 30, 2019.

Yokoo, Y.: Estimating the Occurrence Time of Slope Failure Using Water Stage Data, HS33-A008 (Invited), Asia Oceania Geosciences Society 16th Annual Meeting (AOGS 2019), Singapore, August 2, 2019.

July 11, 2019: Chris talked at the 27th IUGG General Assembly@Montreal

Our PhD candidate, Chris, had a talk on his latest research achievements at the 27th IUGG General Assembly at Montreal. Reportedly, he got supportive comments to his achievements and we are proud of him.

Leong, C., Yokoo, Y.: Estimating Catchments Low Flows in a Disaggregated Flow Duration Curve Approach, The 27th IUGG 2019 General Assembly, Montreal, Canada, July 11, 2019.

May 27, 2019: Poster presentation at JpGU Meeting 2019

Yokoo served a poster presentation at the JpGU Meeting 2019 about our preliminary results on future projection of forest fire frequency.

Yokoo, Y., Iwasaki, R.: Future projection of forest fire frequency due to climate change in Japan by using predicted relative humidity and wind speed, Japan Geoscience Union (JpGU) Meeting 2019, Makuhari Messe, Chiba, Japan, May 26, 2019.

April 24, 2019: Chris's paper was published!

We are glad to announce that Chris's latest paper was published today.

Leong, C., Yokoo, Y. (2019) Estimating flow duration curves in perennial and ephemeral catchments by using a disaggregated approach, Hydrological Research Letters, 13, 14-19. DOI: 10.3178/hrl.13.14.

April 17, 2019: Chris@CECAR8 in Tokyo

Chris gave a talk at "The 8th Civil Engineering Conference in the Asian Region (CECAR8)" today in Tokyo to report his research progress as:

Leong, C. Yokoo, Y.: Estimating low flows in the flow duration curve of catchments in the humid tropics, The 8th Civil Engineering Conference in the Asian Region (CECAR8), Tokyo, Japan, 17 April 2019.

March 31, 2019: Chris's paper was accepted

A new paper written by Chris was accepted for publication by Hydrological Research Letters.

Leong, C., Yokoo, Y. (2019) Estimating flow duration curves in perennial and ephemeral catchments by using a disaggregated approach, Hydrological Research Letters (accepted).

Congratulations! We thank anonymous reviewers and editors for their constructive comments and suggestions. 

March 3, 2019: 5 talks from our group

Chris, Iwasaki, Saito, Suzuki and Yokoyama gave their talks at the Annual Meeting of the JSCE Tohoku branch at Tohoku University.

Nov 30, 2018: Chris gave at a talk!

Leong, C., Yokoo, Y.: Estimating runoff in perennial and ephemeral catchments: adisaggregated flow duration curve approach, The 6th International Symposium on Water Environment Systems, Sendai, Japan, Nov 30th, 2018.

Oct 1, 2018: 6 students joined us!

As of Oct 1, six B3 students joined us our new members listed below

• 1. Kentaro KAMIO, Mr.

  2. Shunya FURUKAWA, Mr.

  3. Ryota MUROI, Mr.

  4. Takeshi SAKAIRI, Mr.

  5. Hikaru SATO, Mr.

  6. Yuki YOKOYAMA, Mr.

Welcome to our laboratory!!

June 14, 2018: AOGS 2018 Report

Yokoo gave a talk at the AOGS 2018 as below:

Yokoo, Y., Yoshida, K., Suzuki, K., Leong, C. A data-based modeling of dominant rainfall-runoff mechanisms: application to snowy watershed, Asia Oceania Geoscience Society 15th Annual Meeting (AOGS 2018), Honolulu, Hawaii, USA, June 4th, 2018 (Invited).

It was a fruitful meeting for me.

April 3, 2018

We are pleased to announce that Mr. Ishikawa have just joined our laboratory member today to support our activities. 

A bit late though, our 4 bachelor students graduate from our laboratory on March 26, 2018.

March 20, 2018

We had received an application to the MEXT scholarship (University Recommendation) for 2018FY. We hope the applicants can win the scholarships.

If you want to apply the scholarship for 2019FY through our laboratory, please contact us via email!! 

February 1, 2018

I came back from Delft, the Netherlands at the end of December 2017.

I would try to boost up our activity with new energy, new ideas, new plans, efficient work-flows, and most importantly our laboratory members!!

Yoshi Yokoo

October 12, 2017

We are pleased to announce that Chris's paper have just published today on the official site of Hydrological Research Letters at:

http://www.jstage.jst.go.jp/browse/hrl 

It means he made his successful debut as a hydrologist today!! Chris, congratulations to you!

September 27, 2017

We are pleased to announce that 4 new B3 students, listed below, will join us as our laboratory members.

• Iwasaki, Ren

• Saito, Ssatomu

• Suzuki, Kaede

• Yokoyama, Kohei

September 21, 2017

We had a presentation at RCEM2017 in Padua, Italy.

Yokoo, Y., Udo, K. Relationship between precipitation, river flow and Its turbidity: fine structure of water and turbidity data at an upper-most reach, 10th Symposium on River, Coastal and Estuarine Morphodynamics, Padua, Italy, September 21, 2017. 

June 27, 2017

We opened a new laboratory web site.

June 21, 2017

We are pleased to announce that our new article was published on line!!

Yokoo, Y., Chiba, T., Shikano, Y., Leong, C. (2017) Identifying dominant runoff mechanisms and their lumped modeling: a data-based modeling approach, Hydrological Research Letters, 11, 128-133. DOI: 10.3178/hrl.11.128. 

May 31, 2017

Started to edit a new group page.