International contributions in advancing ecohydraulics

Ecohydraulics as a research discipline deals with a wide range of topics related to water and ecosystems, thereby contributing to sustainable development goals (SDGs) of the United Nations as pointed out in Findkakis (2017). In Ecohydraulics, interdisciplinary approaches based on hydraulics, hydrology, geomorphology, and aquatic and riparian ecology have been adopted in order to tackle real-world problems in aquatic ecosystems that have complex, inter-related dynamics in space and time (Maddock et al. 2013). The importance of interdisciplinary approaches has now been widely recognized for solving water-related issues in the world specifically by working with nature (WWAP/UN-Water, 2018; Katopodis and Aadland 2006).

With such global trends becoming more evident and advances in technology, ecological, biological as well as physical sciences occurring more rapidly, the context was set in organizing the 12^th International Symposium on Ecohydraulics (ISE2018) was held in Tokyo, Japan from August 19^th to 24^th, 2018. There was large attendance with a total of 484 participants from 35 countries. More than 400 papers including 6 plenary talks were presented. The plenary talks delivered in the symposium were as follows: “Passage for diadromous fishes” by Prof. Katsumi Tsukamoto (Nihon University, Japan), “Use of near-census ecohydraulics in river restoration” by Prof. Gregory B. Pasternack (UC Davis, USA), “How vegetation ecohydrology is changing river management: a primer for all” by Dr. Matthew O’Hare (Centre for Ecology and Hydrology (CEH), UK), “Genomic tools in freshwater ecosystem research and monitoring” by Dr. Michael Monaghan (Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Germany), “The 2018 Brisbane Declaration and Global Action Agenda: A global status report and call for e-flows scientists and engineers to engage” by Prof. Michael McClain (IHE Delft Institute for Water Education, The Netherlands), and “The Ecohydraulics of River Basins” by Prof. Michael Stewardson (University of Melbourne, Australia).

The six keynotes on river vegetation, river restoration, genomics, e-flows and fish passage aimed to provide a deeper understanding of these topics and to foster research activities in the Ecohydraulic Community. Special Sessions, targeting specific ecohydraulic topics, were organized by many ecohydraulicians from around the globe. In addition to these major topics in Ecohydraulics, we observed three emerging topics in the symposium, namely innovative measurement techniques, Ecosystem-based Disaster Risk Reduction (Eco-DRR), and advanced genomics. Innovative measurement techniques such as image-based, optoelectronic and hydroacoustic methods are emerging together with the development of advanced machine learning. Such a development should lead to innovative monitoring systems which can provide new data for a deeper understanding of complex ecological and hydrodynamic phenomena as well as the development of advanced modelling approaches. Eco-DRR has gained international attention after severe disasters caused by tsunamis. Balancing green and grey infrastructure with consideration of risks and costs associated with such disaster control systems is one of the key issues. Environmental DNA is an emerging method used actively for environmental monitoring and assessment in biodiversity research and management. Advances in genomics and bioinformatics can lead to a better management of anthropogenic impacts on ecosystems.

It is noteworthy that the Early Careers on Ecohydraulics Network (ECoENet; https://ecoenet.wordpress.com/) organized an interesting workshop. Young ecohydraulicians, including students, enjoyed keynote talks on the career development of these speakers and interactive quizzes associated with their lectures, as well as round table discussions with senior and leading ecohydraulicians. This workshop was followed by an ECoENet meeting with more participants from all ages at the symposium. We observed growing interests of young scientists and engineers in Ecohydraulics and associated topics and activities. Their active involvement should contribute to the capacity development of future generations of ecohydraulicians as a community working in science and practice.

This special issue of the Journal of Ecohydraulics includes papers from major research lines in Ecohydraulics:

• Environmental flow assessment, including effects from climate change in rivers (Morid et al. 2019) and protection of biodiversity and endemic species in a spring-fed urbanized stream (De-Miguel-Gallo et al. 2019)

• Long-term changes in riparian vegetation cover at pre- and post-dam construction phases (Nallaperuma and Asaeda, 2019)

• Better understanding of flow interactions with aquatic macrophytes using a high-resolution stereoscopic PIV field measurement system (Biggs et al. 2019)

• Use of remote sensing for dispersion studies in river channels, including potential for dispersion of larvae (Legleiter et al. 2019)

• Historical synthesis on the use of fishways in China, their monitoring and performance challenges, as well as recent renewed interest in effective fish passage (Liu et al. 2019)

• Review of ecohydraulics and ecohydrology as integrative disciplines and their complementary roles in river science (Gosselin et al. 2019)

Shinji Fukuda
Tokyo University of Agriculture and Technology, Tokyo, Japan
[email protected]
Norio Tanaka
Saitama University, Saitama Prefecture, Tokyo
[email protected]
Yoichi Yasuda
Nihon University, Chiyoda, Tokyo
[email protected]
Ryota Tsubaki
Nagoya University, Chikusa-ku, Nagoya
[email protected]
Keiko Muraoka
Public Works Research Institute, Tsukuba, Ibaraki
[email protected]
Takashi Asaeda
Saitama University, Hydro Technology Institute, Tokyo
[email protected]

Acknowledgements

We would like to acknowledge all of the participants of the ISE2018 and the authors who contributed the articles to this Special Issue. We appreciate the reviewers diligent efforts to improve the accepted manuscripts. Special thanks are due to the two Editors-in-Chief, namely Christos Katopodis and Paul Kemp, of the Journal of Ecohydraulics, for making the publication of ISE2018 manuscripts possible. We extend our thanks to all the members of international Scientific Committee and others in the Local Organizing Committee (namely Makoto Nakatsugawa, Yasuharu Watanabe, Muneyuki Aoki, Morihiro Harada, Hiranya Jayasanka, and Keiko Muraoka) of the ISE2018 for their active support during the symposium. Lastly, we acknowledge the sponsors of ISE2018, namely Nippon Koei Co., Ltd., CTI Engineering Co., Ltd., the Kurita Water and Environment Foundation (KWEF), the Maeda Engineering Foundation, Tokyo Metropolitan Government, the International Society for River Science (ISRS), the Japan Society of Civil Engineers (JSCE), the Japanese Society of Irrigation, Drainage and Rural Engineering (JSIDRE), the Ecology and Civil Engineering Society (ECES), the Japanese Society of Limnology (JSL), the University of Melbourne, Australia and Nihon University, Japan.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.