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JWF News – August 2020: NoWNET organizes a webinar in the WWWeek At Home on 27th August!


【JWF News Vol. 190】19 August 2020


◇ Contents ◇

・Forward Paradigm Shift: Structural Measures to Complement Co-existence between Humans and Nature

・Announcement from the Japan Water Forum
– NoWNET organizes a webinar in the WWWeek At Home on 27th August!

・Report from the Japan Water Forum
– Progress on JWF Fund 2020
– JWF Fund 2019: Reconstruction of Kyageefa Water Spring (Uganda)
– Worldwide Mission Uchimizu 2020: “Hoping water will reach people in need” & Our Efforts on Water Day, 1st August
– The JWF Water Journal Digital Archive is now available


・Foreword Paradigm Shift: Structural Measures to Complement Co-existence between Humans and Nature
By Dr. Takehiko OTA, Advisory Council Member of the Japan Water Forum, Professor Emeritus, The University of Tokyo


Japanese Mountains and Forests have Recovered from Devastation
Though Japan is said to be rich in water resources, torrential rains often cause flooding and landslides. Since the late Showa period, when those who are now senior citizens were involved in efforts to prevent such disasters, the background of national land conservation went through two drastic changes.

The first change occurred during the period between the late Showa period and early Heisei period, when vegetation was restored to Japanese forests as trees re-grew after several hundred years of degradation. In the mid-Showa period, surface erosion and debris slides had frequently caused landslides. As a result, large volumes of earth and sand flowed into rivers and onto beaches. In many major rivers across Japan, flooding occurred frequently as river improvement work had not been completed.

In the Heisei period, thanks to ambitious river improvement programs, the construction of large dams and the recovery of forests, flood damage along major rivers drastically decreased, surface erosion ceased, and debris slides became less frequent. This meant that we had almost conquered flooding and landslides caused by deforestation. We recognized that the continuous efforts at forest conservation and flood control since the time of Banzan Kumazawa, a prominent scholar and politician of the early Edo period, were almost complete. Future programs for forest conservation and flood control will focus on mitigating landslides and water-related disasters, which we have no choice but to accept as the Japanese archipelago is located in the monsoon region of East Asia and along the subduction zone of tectonic plates.

During the Heisei period, there was a debate about disaster control measures: “artificial dams or green dams (forests)”. Today, however, we have reached a consensus about the merits and demerits of dams as well as the functions and limits of forests. In managing national land, it is desirable to adopt measures that get the best out of both methods and compensate for the shortcomings of both.

In the Days of Global Challenges
The second change to land conservation policy was the increase of large-scale heavy rains due to global warming, which became apparent towards the end of the Heisei period. The tsunami triggered by the Great East Japan Earthquake was the worst water-related disaster. Towards the end of the Heisei period, however, record heavy rains frequently occurred across Japan every year, causing flooding along major rivers. A backward glance shows that the halcyon days of nearly forty years were over, when we could enjoy the fruits of river improvement work since the Showa period. We have to accept the fact that the climate has changed. If this were not happening, we would be able to simulate the scale of flooding in an area in response to the exceedance probability of heavy rain by taking fluvial geomorphology into account. This is not the case in an era of climate change.

It is noteworthy that not only flooding but also landslides have greatly changed. In the past, multiple debris slides would often merge into a debris flow. Today, many debris flows arise from a single debris slide. Although the number of debris slides has decreased as a whole, a debris slide can be turned into a debris flow by an intense flow of effluent water from forested mountainsides due to increasingly heavy rains (resulting from global warming) that erodes and mobilizes soil or rock on steep slopes. Even in areas along mountain streams with no apparent surface failure, river banks and river beds are deeply eroded by effluent water. In the Reiwa period, we must find new measures against expected water-related disasters, including those caused by forest debris and bedrock slides.

Thinking from the perspective of co-existence with nature
The flooding on the Kuma River caused by torrential rains in July, 2020 far exceeded our assumptions. As someone involved in the dispute about “green dams” on the Kawabe River, I am interested in the assessment of how much the damage from this flooding would have been reduced if a dam had been constructed. However, in the current environment of global warming, a drastic change in thinking will be required. For example, we need to shift from our conventional way of thinking, in which we first planned land use and urban construction programs beneficial for humans, and then designed structural measures, such as dams and embankments. After that we took non-structural measures, such as warnings and evacuation, and only in the end gave slight consideration to conservation of the natural environment.

In contrast to such a conventional way of thinking, we need to adopt an utterly new concept of land use and urban planning, which first pursues co-existence between humanity and nature, and takes disaster prevention into consideration. Then, we can use eco-DRR (disaster risk reduction utilizing eco-systems), followed by non-structural measures. Lastly, structural measures to complement non-structural measures can be introduced. I think we need to adopt this new way of urban planning, which combines structural and non-structural measures for disaster reduction.

NLvol.190phThe confluence of the Kawabe (right) and the Kuma Rivers, Kumamoto
(Photo taken by KOKUSAI KOGYO CO.,LTD. July 7, 2020)


・Announcement from the Japan Water Forum


– NoWNET organizes a webinar in the WWWeek At Home on 27th August!

WWWeek At Home is a new series of virtual sessions that lets anyone tap into the knowledge of some of the greatest water and climate experts. It was born as the alternative area of the regular World Water Week, which had to be cancelled due to COVID-19 and as an umbrella under which organizations can host virtual adaptations of their World Water Week-approved sessions.

Japan Water Forum, Secretariat of NoWNET, will organize a webinar entitled “Co-Benefits of Implementing NBS for Water Resources and Flood Risk Management” with NoWNET members on 27th August 2020 10 am CET (17:00 Japan time).

▼Please visit the following website for details▼,rep_en

(Reported by Yumiko Asayama, Manager) 


・Report from the Japan Water Forum


– Progress on JWF Fund 2020

The JWF Fund was founded in 2005 and is operated solely by the Japan Water Forum (JWF), which aims to support selected grass-roots organizations in developing countries that have been addressing local water-related issues. The JWF Fund is based on JWF membership fees and donations from general contributors.
During a month of the application period, the JWF received 347 applications from 35 countries, which submitted by those involved in activities aiming at solving problems of water supply, sanitation, and water-related disasters.
The JWF is now in the process of examining the applications, and the recipients will be announced by middle of September.
The results of the selection will be announced to all applicants by e-mail and the selected projects will be posted on the JWF website.

▼Please visit the following website for details of the JWF Fund▼

(Reported by Shigenori Asai, Director and Akie Gunji, Sub Manager)


– JWF Fund 2019: Reconstruction of Kyageefa Water Spring (Uganda)

Under the JWF Fund 2019, seven projects in six countries were selected and funded out of 302 applications submitted from 36 countries.
The completed project report will be posted monthly.

▼Project in Uganda▼,rep_en

(Reported by Shigenori Asai, Director and Miyo Tabata, Assistant Manager)


– Worldwide Mission Uchimizu 2020: “Hoping water will reach people in need” & Our Efforts on Water Day, 1st August

On August 1, Worldwide Mission Uchimizu was held. We called on people across the world to join us from home and uchimizu (sprinkle water) anywhere, anytime during the day.

▼Please visit the website of the Mission Uchimizu Headquarters for details▼

The Japan Water Forum is promoting uchimizu, hoping that water will reach people in need across the world through the global water cycle. Let’s practice uchimizu (sprinkle water) every day during the Uchimizu Month until August 23. After uchimizu (sprinkling water), please share your experience on social media using the hashtag #uchimizu.

▼Please visit the following website for details▼

(Reported by Shigenori Asai, Director)


– The JWF Water Journal Digital Archive is now available

In conjunction with the annual Water Conference for Future, organized by the JWF, volumes 1 to 4 of JWF Water Journal have now been published. 

Back issues of JWF Water Journal are available on the website. Please visit following website to access them, along with the record of past meetings of Water Conference for Future.

▼Please visit the following website for details▼,rep_en

(Reported by Sayoko Kuwahara, Manager)


▼JWF News Archives▼,rep_en

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JWF News Vol. 190 / 19 August 2020
Japan Water Forum

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