The Nagara River and Climate Change
Gifu University Regional Adaptation Research Center

Date of interview	September 8, 2020
Targets	Professor Morihiro Harada, Professor Shuichi Nonomura, Professor Hiroyuki Muraoka, and Professor Keijiro Okuoka, Gifu University Regional Adaptation Research Center President Yusuke Kaba, NPO ORGAN

Abnormal changes in the Nagara River

What kind of changes are occurring in the Nagara River basin in recent years?

Mr. Harada: “Sweetfish of the clear stream of the Nagara River,” a Globally Important Agricultural Heritage certified in 2015, has been highly evaluated as the “Nagara River System” that is formed upon deep involvement and interactions of agriculture, forestry, inland fishery, commerce, and tourism with satokawa (a river that enriches the lives of people in the basin through proper management) as the keyword. One of the issues of concern in this Nagara River basin in recent years is the impact of climate change. Flooding and droughts that are occurring more and more frequently, scarcity of sweetfish caused by high water temperatures, impact on ukai spectator boat business, decrease in the number of tourists due to the heat waves, etc. are being concerned. When we observe the history of floods in the past, it is evident that many in the Nagara River were caused by heavy rain from typhoons. In the Typhoon No. 23 disaster in October 2004 which recorded the highest flow in the Nagara River, inundation above floor level occurred in hundreds of houses in the upstream areas of the river. However, heavy rain damages caused by the seasonal rain front have also increased recently. There were large-scale flooding damages in the Nagara River range in the July 2018 heavy rain. Rivers including the Tsubo River, which is a tributary of the Nagara River, overflowed due to the heavy rain with continuous rainfall that exceeded 1000 mm. Even though they closed all the floodwall gates installed in the riverside land, people experienced the fear of being flooded to the ceiling of the first floor. In addition, flooding disasters have occurred consecutively in 2019 and 2020.
Cormorant fishing (ukai) on the Nagara River, which has a history of more than 1300 years, is an important economic resource in the local tourism. Since sweetfish grow in the upstream and middle reaches and end their life in a year, it is a migratory fish species that is susceptible to flooding, drought, etc. of each year. It has been pointed that there is a trend for the number of individuals that swim upstream in the following year to decrease when the spawning timing for sweetfish is delayed. Water temperature is deeply related to everything in their life cycle from swimming upstream to growing and spawning, and there have been study results that show that diseases related to high water temperatures occur in the river ecosystem if the water temperature is 25C or higher. In the “Complex Climate Change Impact Assessment and Adaptation Measures in Regional Scale,” which is being implemented with the Environment Research and Technology Development Fund for a 3-year period starting this fiscal year of 2020, we study how river environments change and what impacts are caused on the local economy if flood occurrence increases in frequency and the water temperatures rise due to climate change. Professor Okuoka also studies the social values of sweetfish from the viewpoint of environmental economics. We participate in discussions with the stakeholders by incorporating external forces of climate change and predictions in the local problem awareness with a hope to switch to new measures or strategies.

A new attempt called Kawa Sajiki (riverside seats) (Nagara River Ukai Sajiki)

Please tell us about the recent situation of cormorant fishing (ukai) on the Nagara River and the hot spring area in vicinity.

Mr. Kaba: Cormorant fishing (ukai) on the Nagara River has had a very hard time in the last several years. In a normal year, more than 100,000 tourists took tours on the spectator boats during the cormorant fishing period from May 11 to October 15, and Nagara hot-spring resorts received 300,000 guests throughout the year. However, after the Western Japan Heavy Rain in July 2018, the spectator boats had to be cancelled for 42 days, even though cormorant fishing went on. As a consequence, the number of tourists decreased by a few dozen thousand because the spectator boats were not available during the peak season, even though they took urgent measures including viewing of the fishing from the riverbed.
Under such circumstances, they have considered the adoption of a method to view cormorant fishing from the riverbed for the last few years. There used to be a style for viewing cormorant fishing from a riverside building called “evening cool seat” in Gifu, and we examined alternative methods for viewing cormorant fishing other than spectator boats that are suited to the modern age, and conducted a social experiment on “Nagara River Ukai Sajiki (riverside seats)” (Youtube). Although it was quite difficult to pave the way to the realization, awareness that the use of spectator boats was difficult due to the heavy rain disasters spread, which resulted in a sudden advance in consensus forming within the community. The trial attempt was finally implemented in October 2019. Since the fluctuations in river water level have recently become more dramatic with the level suddenly increasing or decreasing, Sajiki has been designed so that it can be dismantled and removed within 30 minutes in case the water level increases. Gifu has a culture of holding banquets with geisha, and they are already receiving inquiries from tourism companies, etc. as an experience with high added values where tourists can enjoy watching cormorant fishing and geisha entertainment. In the future, we are planning to develop a mechanism for selling this as a regular tourism product.

Please tell us about the joint council that was launched by the Ministry of Land, Infrastructure, Transport and Tourism, which is the river administrator, City of Gifu, etc.

Mr. Kaba: In the beginning, we had study meetings in a framework called “Mizbering,” and there were riverside stakeholders who had searched for the possibilities of utilization of the Nagara riverbank. At present, the City of Gifu is taking the leadership to implement riverside development planning, mitigation of regulations for private businesses, discussion on event holding, etc. While Professor Harada is also participating in this, I think the Nagara River is one of the top areas in the types, number, and profit of stakeholders related to rivers among the river town developments in Japan. For example, cormorant fishermen and fishermen use the Nagara River. The environment and the fishery resources are protected because of them. There are also many city residents who swim in the river or enjoy barbecue. Today, we feel that we have an opportunity for the concerned parties including fisheries, tourism, environment, flood management, and urban development to gather and bring together the stakeholders who had been working individually before, and that there is finally a place for them to discuss not only climate change but also other urgent issues. Although things will not go easily as circumstances vary by the region, I feel grateful that we have progressed to such a stage after being involved in urban development for 17 years.

Challenges by the Gifu University Regional Adaptation Research Center

What tasks does the joint council expect from Gifu University? And what kind of creative efforts should a community make when promoting adaptation?

Mr. Harada: This joint council is participated by multiple stakeholders in the area, including Nagara River cormorant fishermen, the tourism industry in the region, the City of Gifu, and the Ministry of Land, Infrastructure, Transport and Tourism, which is the river administrator. The university tries to dig into various motivations of these stakeholders. Naturally, the joint council and the local community do not have the intention of doing something for climate change. We ask them to share the local issues and field knowledge of each. It is important that we make the approach and think about the impacts that can be predicted in the future as well as the methods to prepare for the risks together, instead of waiting for them to share their needs. In our case, we had something common between the society Mr. Kaba and others aimed to achieve and the desired future we envisioned. I believe we were able to find a common front after repeating discussions. As researchers, we are always prepared to provide the scientific findings to help plan a society that adapts to climate change in the movements to tackle local issues and change the present to the better.

Please tell us about the characteristics and roles of the Regional Adaptation Research Center, which was founded in April this year.

Mr. Harada: To respond to the wide range of needs in the region, the Regional Adaptation Research Center brought together experts in various different fields within the university. It consists of 6 different research divisions, which are Regional Climate Change, Forest Ecosystem and Resources, Agricultural Adaptation, Water Environments, Social Systems, and Regional Collaboration, and there is a system which facilitates the researchers from different divisions to have discussions with one another. Since management of matching between the regional needs and the specialty of researchers is extremely important, each division head has the producing capabilities to do so. I feel that specifying a study theme that would ensure balance between the two is important, as researchers need to solve a regional issue while also delivering scientific outcomes.

Mr. Muraoka: We are currently trying to shift to application in adaptation from the accumulation of research related to forests, water, substances, etc. that the River Basin Research Center had worked on so far. In this system, young researchers within the university will gather and respond to the demands of the new generation. Researchers are establishing cross-cutting networks and working with division of roles. Meanwhile, there are issues in continuing such activities. Sustainable development is essential so that we can self-support for activity costs in the future. I also expect that development of the capacity in society to prepare for adaptation is another issue to be handled at the same time as research activities. It is important to understand the other party and have them understand us, and therefore I believe that communication based on future predictions in addition to the past history is also important.

Mr. Harada: I consider utilization of scientific findings as an issue of literacy. The judgment of the national government on the novel coronavirus is one of the examples where the opinions of scientists were reflected. I expect that there will be a day when we will provide and explain the scientific findings on adaptation carefully so that they are utilized in policies. I believe that capacity building as well as dissemination and awareness raising are therefore necessary.

Mr. Okuoka: I joined Gifu University in October of last year. I used to belong to a laboratory for civil engineering, and conducted research on social evaluation with environmental economics and energy with a focus on environmental research. I believe adaptation is to form each community with everyone cooperating with good balance in relation to the Sustainable Development Goals (SDGs), etc. I hope to contribute to establishment of such a society, however small the contribution may be.

Mr. Harada: What will happen in 10 years, or 20 years? I get together with my colleagues and discuss with them because I want to know, while I do have hopes for what I want to happen. I tell my students that they should not expect the current society to exist 10 years from now. I hope to discuss and think together with the stakeholders what scenario we will adopt in the future, while also nurturing the capacity for adaptation to respond to unexpected situations, learning the field, and conducting analysis.

Mr. Nonomura: As the successor of the River Basin Research Center, the Regional Adaptation Research Center has many young and excellent researchers participating. It is important that we also acquire national research funds such as the promotion fund, and continue delivering outcomes that are utilized in the region. I believe it is now time for researchers to consider how to return to the community while using the specialty of each as the foundation.