IGES Working Paper

Synergistic actions on climate change, biodiversity
and the SDGs – three cases from Japan
Institute for Global Environmental Strategies
Integrated Sustainability Centre
Authors: Nobue Amanuma and Shinji Onoda
Contributor: Junichi Fujino
July 2023

Minamisanriku Town
1. Background⚫

Minamisanriku Town is home toabout 12,000 people. It is locatedin the north-east of Miyagi
Prefecture, on the southern part ofthe Sanriku coast.

⚫

The town's area extends from theheadwaters of streams to the sea,and its rich natural environment
supports aquaculture and tourism.

⚫

The town’s boundary is a watershed, and rainfall flows into the bay through streams, which run
through the town. This geographical feature of Minamisanriku means that land-based activities inthe town have a significant impact on the fishing industry in the bay.

⚫

Overcoming the damage caused by the Great East Japan Earthquake, Minamisanriku aims tobecome a sustainable, self-sustaining and decentralised town.

2. Restoration of seaweed beds (blue carbon)⚫

Minamisanriku is located facing Shizugawa Bay, which is home to more than 200 species ofseaweed and seagrass, and boasts high biodiversity, including the endangered brant goose or
kokugan which winter there. In 2018, the bay was registered as a Ramsar Convention wetland.
Recently, the area of seaweed beds was found to be decreasing due to damage from theearthquake and the effects of rocky shore denudation that is spreading nationwide, as such,restoration of the seaweed beds has become an urgent issue. Therefore, the Minamisanriku
Nature Center, in collaboration with the Center for Sustainable Society and a private company, ispromoting the restoration and expansion of seaweed
beds in Shizugawa Bay. The aim is not only to maintainbiodiversity but also to convert blue carbon into credits
by making eelgrass and other seaweed function as aCO2 sink. In collaboration with Tohoku University,
analysis is also being carried out on how to increase
biodiversity through the expansion of seaweed beds.
Seaweed beds under restoration
Photo by Akihiro Dazai

13. Biodiversity-conscious forest management⚫ Properly managed forests are important CO2 sinks. Minamisanriku is 70% covered by forests, andthe town is managing the forests with biodiversity in mind, with the coexistence of cedar, red pine,and cypress along with subvegetation. Zoning is implemented for riparian forests. In addition, theMinamisanriku Forest Stewardship Council obtained FSC certification in 2015. Sakyu Corporation,
which is a member of the Minamisanriku Forest StewardshipCouncil and supports the local forestry industry, is also
working with the World Wildlife Fund to research andanalyse how FSC's efforts comply with the Taskforce on
Nature-related Financial Disclosures. By proactively
disclosing information, the company aims to support
information disclosure of wood user companies, which maylead to purchase of certified woods and protection of nature.
Forests certified by FSC®️Photo by Akihiro Dazai

4. Other Synergies⚫

In 2016, the Shizugawa Branch of the Miyagi Prefecture Fisheries Cooperative, practisingaquaculture off the coastline in Shizugawa Bay in Minamisanriku Town, became the first in Japanto receive ASC certification for oyster farming with reduced environmental impact. Before theearthquake, good quality oysters were not produced even after three years due to overcrowding.
After the earthquake, the area under cultivation was reduced to one-third, and the water quality andnutrition was improved, meaning that after only one year, oysters were ready to be shipped. This
increased oyster farmers’ income by 1.5 times and reduced working hours by 40%.

⚫

Organic waste from homes and stores in Minamisanriku is fermented and processed to produce
biogas and liquid fertilizer. The biogas is used to generate electricity, and the liquid fertilizer isapplied to farmland as a fertilizer. This project has created an intra-regional cycle of resources,energy and food.

Oyster farms in Shizugawa Bay in the past (left) and the present (right)
Photo by Akihiro Dazai

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Maniwa City
1. Basic Information⚫ Maniwa City is located in the centralnorth part of Okayama Prefecture,and roughly in the centre of theChugoku Mountains.
⚫

The total area of Maniwa isapproximately 828 km², and about
80% of the city area is forested, withabundant forest resources.

⚫

The forestry industry has been
thriving for a long time, and the production of cypress in Okayama has been the highest in Japan
since 2012, except for 2017. On the other hand, large amounts of forest residues and wood wastehave not been used effectively, having been disposed of or abandoned.

⚫

In 2006, Maniwa City announced its “biomass town concept” with the aim of making better use of
these unused woody resources, and was certified as a biomass town by the national government.

⚫

Biomass power generation produces benefits such as ensuring resilience to natural disasters,
revitalising local industries and communities, and preserving biodiversity in secondary forests.

⚫

Maniwa City declared itself a Zero Carbon City in 2020, and aims to achieve 100% selfsufficiency in renewable energy by utilising forest resources and building a forestation andtimber industry cluster.

2. Biomass power generation⚫

Ten organisations, including Maniwa City and local forestry-related business entities, invested toestablish Maniwa Biomass Power Corp in February 2013, and the Maniwa Biomass Power Plant
began operating in April 2015. The scale of operations is 10,000 kW, and the operating rate is103%. Annually, the plant uses 110,000 tonnes of biomass as fuel and generates 79,200 MWh(enough for 22,000 households).

⚫

By efficiently accumulating thinned wood, forest residues
and lumber offcuts generated from forests, the company isable to stably supply and generate power from biomass asfuel for power generation. This has contributed to an annual
reduction of 80,000 tonnes of CO2 emissions and anincrease in energy self-sufficiency (from 11.6 to 37.3%). In
addition, the company aims to use about 350,000
tonnes/year of biomass and reduce CO2 emissions by about
300,000 tonnes/year.
Biomass Power Plant
Photo by Maniwa City3⚫

Establishing and using the information management system, which covers resource procurement todistribution, Maniwa City created a system to return profits to forest owners. By trading fuel, whichused to be unused or disposed of as industrial waste (with disposal costs equivalent to JPY 100
million or more), as a valuable resource, approximately 20 materials suppliers and 30 lumber
companies have increased their profits. In addition, JPY 550 /tonne of the fuel cost is returned toforest owners.

⚫

In the past, logging companies abandoned most of the wood left over from logging in the mountains.
This led to soil weakening, disruption of ecosystem balance, and was a potential cause of disasters.
However, now that forest residue has become a valuable resource, it can be removed from themountains, making it easier to manage the mountains including through reforestation.

⚫

Maniwa City now promotes main cutting and thinning of planted forests by utilising the forest
environment gift tax.

⚫

The city is also working on the cyclical use of broadleaf forests, the revival of mountain burning,
and the restoration of wetlands.

Fostering forests that produces energy
Photo by Maniwa City4

Lake Inba and its basin
1. Background⚫ Lake Inba is located in the northern part of Chiba Prefecture. Thebasin area is about 541 km2, accounting for about 10% of theprefecture's total area. Its watershed spans 13 cities and towns,
and the population of the basin is approximately 790,000. There
are about 600 small valleys or yatsu in the watershed.
Groundwater from the plateau comes to the surface as springs
where the valley slopes meet the plains (at the edges of the valley
floor of yatsu), and these springs collect to form rivers, which inturn flow into Lake Inba.
Source: JICA Japan's Experience onWater Resources Management
Theme 2-2. River Basin Planning

2. History⚫ Until around the 1950s, people practiced paddy rice cultivation mainly on the valley floor, taking
advantage of the abundant spring water. In addition, valley slopes and the top of the plateau
provided fertilizers needed for agriculture and grass to feed cattle and horses. The grasslands andforests on the plateau maintained for agriculture and daily life also helped to recharge groundwaterand maintain spring water, and land use was integrated with the water cycle.
⚫

After the 1960s, fallow and abandoned cultivation became widespread, and after the 1970s,urbanisation, mainly on the plateau, led to land reclamation in the valleys. Grasslands and forests
were replaced by asphalt, concrete and other materials that do not allow rainwater to permeate theground, and as a result, springs in the valleys decreased.

⚫

In addition, many native plants and animals were decreasing and even disappearing in Lake Inba,
while alien species such as black bass and snapping turtles invaded and bred in the surroundingarea. The ecosystem deteriorated day by day. COD, an indicator of water quality, significantly
exceeded environmental standards (COD75% value: 3 mg/L), and in 2007, the lake became one of
the worst lakes in Japan in terms of water quality.

⚫

In the basin, flood flows increased due to rapid land use changes such as residential development.
In October 2019, heavy rainfall exceeding 200 mm in a short period of time caused flood damage
due to leaks from levees and overflows in the incoming rivers. There are concerns that global
warming will lead to an increase in rainfall and more frequent flooding in the future, making itimperative to act.

53. Restoration of Lake Inba and its Watershed⚫ In October 2001, Chiba Prefecture established the "Committee on restoration of sound hydrologic
cycle in Inba-numa watershed" consisting of concerned parties (residents, academics, water usergroups, and local government) in order to improve water quality and restore the naturalenvironment in the basin. In February 2004, the "Emergency Action Plan for Sound Hydrologic
Cycle in the Inba-numa Basin" was formulated, but it failed to improve water quality. Based on theresults obtained from the emergency action plan, new initiatives were added, and the "Plan for theSound Hydrologic Cycle in the Inba-numa Basin" (Master Plan) was formulated in January 2010
with a target year of FY2030 (subsequently revised in March 2017 and March 2022). Based on thisplan, the 3rd Action Plan was formulated in March 2022, which stipulates specific measures.
⚫

The 3rd Action Plan incorporates the concept of "River Basin Disaster Resilience and Sustainability
by All," in which all parties involved work together to address the impacts of climate change andchanging social conditions throughout the basin, with the aim of using this as a driving force torevitalise efforts to improve the sound hydrologic cycle. In addition, the plan aims to improve theattractiveness of the waterfront area by creating a network linking the rich natural environment,
history, culture, and tourist facilities.

⚫

In addition to river improvement and levee maintenance, efforts for river basin disaster resilienceand sustainability by all include the conservation and utilization of valleys and satoyama, mainly
through the use of green infrastructure, and measures in catchment areas such as paddy fieldstorage and rainwater harvesting and infiltration measures.

⚫

The "Green Infrastructure Initiatives Utilizing Abandoned Valleys" have brought multiple benefits by
wisely utilizing the various functions that valleys have to offer.
➢Utilization and improvement of valley topography (e.g. restoration of abandoned rice paddies,)
to slow runoff of rainwater (flood control effect)➢

Removal of nitrogen and phosphorus, which cause water quality deterioration in the Lake Inba,
by slowly allowing rainwater and spring water to flow into the preserved and restored wetlands
within the yatsu, (water purification)➢By conserving and restoring wetlands, valuable organisms that prefer wetland environments
are conserved and restored (ecosystem conservation).

➢Utilization of the preserved and restored yatsu environment as a place for environmental
education and community exchange and recreation (community revitalization).

➢

Beautiful landscape of well-kept yatsu (local landscape formation)

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Utilisation of abandoned yatsu

Effects of yatsu
Disaster Prevention and Mitigation Effectiveness-

About 10 times more effective in delaying runoff(Comparison between an urbanised valley and a valley with surrounding forests,
grasslands, and wetlands)-Reduction of precipitation runoff to rivers by 30% or less(In urbanised valleys, 70-100% of the precipitation runs off.)

Water purification effect-Nitrate nitrogen concentration decreased from 20 mg/L to 0-5 mg/L

Source: Based on Green Society Working Group, Environment Subcommittee and Technology Subcommittee, Council
for Social Infrastructure Development and Council for Transport Policy, Ministry of Land, Infrastructure, Transport andTourism

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References:
Minamisanriku Town⚫

Center for Sustainable Society (2023). Mori Sato Umi Hito Inochi Meguru Machidukuri
Minamisanriku (Becoming a circular town: Minamisanriku) Nikkei SDGs Forum 2023
https://youtu.be/f4FFxfV_IcA (published in Japanese)⚫

Forest Stewardship Council. Minamisanriku Shinrinkanri Kyougikai (Minamisanriku
Forest Stewardship Council) https://jp.fsc.org/jp-ja/Minamisanriku (published inJapanese)⚫

Minamisanriku Portal Center (2021). Our Hometown Minamisanriku
https://www.m-kankou.jp/kankou/wpcontent/uploads/2021/03/2c87168e1b35af005623fefca7ffbe8c.pdf

Maniwa City⚫

Maniwa City (2021). The use of Biomass for a Low-Carbon Society
https://www.iges.or.jp/sites/default/files/inline-files/25_Maniwa_OTA%20Noboru_01_%EF%BC%A3%EF%BC%AF%EF%BC%B0%EF%BC%92%EF%BC%96%EF%BC%88%E8%8B%B1%E8%AA%9E%EF%BC%89873_1029.
pdf⚫

Nakajima, Koichiro (2020). Maniwa Baiomasu Hatsudensho ~Junchou na Kadou noRiyuu to Kongo no Kadai (Maniwa Biomass Power Plant: Reasons for sound operationand challenges ahead) https://www.econ.kyotou.ac.jp/renewable_energy/stage2/contents/column0167.html (published in Japanese)

Lake Inba and its basin⚫

River Environment Division, Land Development Department of Chiba Prefecture (2022).
Inbanuma Ryuuiki Mizujunkan Kenzen Keikaku, Dai 3ki Koudou Keikaku no Sakutei nitsuite (Plan for the sound hydrologic cycle in the Lake Inba basin)https://www.pref.chiba.lg.jp/kakan/press/2021/inbanuma3.html (published in Japanese)⚫

Nishihiro, Jun (2022). Mizube Kankyou no Hozen, Katsuyou, Renkei (Preservation,utilization, and coordination of the riparian environment)
https://www.env.go.jp/water/project/project/practice20220302/pdf/220302_gp_01.pdf(published in Japanese)

This report was developed as part of a project funded by the Ministry of the Environment, Japan. We would like to thankAkihiro Dazai at the Center for Sustainable Society, Takahiro Sugimoto at the Energy Policy Office, Forestry and Biomass
Industry Division, Maniwa City, and Shinichiro Hara of the River Environment Division, Chiba Prefecture, for theirinvaluable cooperation in preparing this report.

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Integrated Sustainability Centre
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The views expressed in this working paper are those of the authors and do not necessarily
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