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Abstract This article focuses on how ecosystem-based approaches could be mainstreamed in recovery and reconstruction after large scale, rare and infrequent coastal hazards. In doing so, this study reviews historical practices of disaster management in rivers and coasts as well as reconstruction process after the Great East Japan Earthquake (GEJE). It reveals how ecosystem approaches are integrated in river and coast works and highlights some of the relevant policies, technical guidance and guidelines and good practices on the ground. This study also documents how Eco-DRR policy evolved and implemented after the GEJE and addresses some of the challenges in its implementation. In order to draw additional insights, the reconstruction processes of Hurricane Sandy in the United States (US) was also reviewed as GEJE and Sandy shares some common features. Experience from Sandy suggests the importance of the participatory planning process rather than technical guidance or guidelines. Although it is too early to judge whether either reconstruction process was better or not, nor difficult to generalize the conclusion from only two samples, these two experiences suggest only technical guidance and guidelines is not sufficient to mainstream Eco-DRR/CCA in the reconstruction from large scale, rare and infrequent disasters. It is also suggested that the critical role of participatory planning process with cross-sector, cross-professional and interactive design approach may lead more innovative solutions. [ABSTRACT FROM AUTHOR]

Selecting sites for river restoration projects or performing ex post evaluation must be done in ecoregions with comparable biological integrity. Moreover, to evaluate the integrity of a river ecosystem that varies from the headwater to downstream regions, adjustments of the ecoregion according to the longitudinal change in biota must be made. We defined regions where biota are identical according to the direction of change along the stream path as “segment-based ecoregions.” We delineated segment-based ecoregions using fish fauna data for two ecoregions in Japan: the northeast Kyushu, and south Kyushu. The northeast Kyushu ecoregion was divided into three segment-based ecoregions, and south Kyushu ecoregion into five segment-based ecoregions. Classifying fish fauna within the same ecoregion enables classification by differences in the longitudinal change in the stream path rather than by differences in watersheds. Specific topographic regions such as the amphitheater areas of the south Kyushu ecoregion was classified as independent segment-based ecoregions. We further defined indicator fish species for each segment-based ecoregion. Indicator fish species reflected the fish fauna of each ecoregion in the midstream area, such as migratory Gobiidae of the south Kyushu ecoregion. Applying the segment-based ecoregion concept helps compare the biological integrity of fish fauna depending on a common environmental type between watersheds. [ABSTRACT FROM AUTHOR]

Frequent inundation has become a serious problem in urban areas. It is necessary to improve rainwater retention/infiltration in the urban watershed. The purpose of this study is to report how private rainwater-retention/harvesting facilities can be spread gradually but steadily in the city by citizen-initiated activities. Rainwater harvesting tanks were installed intensively and a rainwater harvesting house was constructed in the city of Fukuoka, Japan after the city experienced a flood disaster. The former enhanced users’ daily preparedness for emergency, and the latter inspired construction of a rainwater-harvesting housing complex. A public elementary school is in use from April 2016, which is inspired by these facilities. The school premises are located on the land reclaimed from an old irrigation pond. Thus the school needs to be adapted to this condition. 3000 m 3 of rainwater can be retained within the premises. The amounts of retention and discharge are monitored, and the data is utilized for science education. In big cities, people tend to depend too much on the top-down, mega-system, which invites more impervious surfaces in urban areas. Bottom-up, individual/collaborative approaches should be adopted in order to achieve multiple purposes of preventing/mitigating disasters, preserving/conserving ecosystems and nurturing/rebuilding communities in the city. [ABSTRACT FROM AUTHOR]

Frequent inundation has become a serious problem in urban areas all over the world in recent years. It is necessary to improve rainwater retention and infiltration in the urban watershed. The purpose of this study is to report how private rainwater-retention/harvesting tools/facilities can be spread gradually but steadily in the city, as a smart way to responding to urban flood-disaster risks. Rainwater harvesting tanks (0.2 m 3 ) were installed intensively in 2010 and a rainwater harvesting house (42 m 3 ) was constructed in 2012 in the city of Fukuoka, Japan after the city experienced a flood disaster in 2009. The former enhanced users’ daily preparedness for emergency, and the latter inspired construction of a rainwater-harvesting housing complex (108m 3 ) in an adjacent city. An elementary school is under construction from November of 2014 by another, nearby municipality inspired by these facilities. The school premises are located on the land reclaimed from an old irrigation pond. Thus the school needs to be adapted to this condition. 3,800 m 3 of rainwater can be retained within the school premises. The water is used to flush the toilet and water flowers to be grown by pupils. The amounts of retention and discharge will be monitored, and the data will be utilized for science education. In big cities, people tend to depend too much on the top-down, mega-system involving dredging rivers, strengthening drainage systems, constructing flood walls, etc., which invites more man-made, impervious surfaces in urban areas. Bottom-up, individual and/or collaborative approaches should be adopted in order to achieve multiple purposes of preventing/mitigating disasters, preserving/conserving ecosystems and nurturing/rebuilding communities in the city. [ABSTRACT FROM AUTHOR]

Small scale hydropower energy goes a long way to fire up community development. Until 1920-30s, Japanese hydropower techniques had been established on a global level in each local area. However, after the second World War, the main energy resource was changed. This has resulted in a local decline in micro-hydro technical expertise and fewer waterwheel makers throughout Japan. At the present, we are going to work to re-make small scale hydropower technologies and markets. In this paper, we discuss and propose improvements to the “Japanese” small scale hydropower technology and production techniques, especially Pelton type wheel. The Pelton wheel technology of Nepal was freely available in the public domain so we decided to design a system based on that. We decided to designed by 3D-CAD and to make our Pelton buckets using a 3D printer. We compared the power generation capacity of our waterwheel with one purchased from New Zealand to investigate its effectiveness and efficiency. In our results of the experiment, the power generation curves for each turbine are approximately equal. The power increases continuously with increases in the flow rate. The maximum power generated by each turbine is approximately the same. This shows that it is possible to design a Pelton bucket that has a power generation efficiency comparable to a purchased bucket. The next step, the Pelton turbine designed in this study was chosen to be included in the Itoshima micro-hydro power generation system. So we scaled up and redesigned the Pelton turbine. In addition, we conducted a survey involving waterwheel makers regarding connecting to cost reduction. Using a 3D printer has the following advantages: 1.) Design deficiencies and failed designs can be identified at an early stage. 2.) Different forms of waterwheel can be made at low cost and in a short amount of time, which can then be used to run water experiments. [ABSTRACT FROM AUTHOR]

To break the ‘carbon lock-in’ mindset adopted by policy makers, the potential for mass rural remigration, as an alternative to the current trend of moving from rural to urban areas was examined. The capacity of renewable energy to maintain populations in hilly and mountainous farming regions was evaluated from two perspectives: (1) an average nationwide estimate based on the future energy demand, and (2) a conservative estimate based on the current energy demand. Because estimate (2) indicated that Hokkaido has a huge capacity, a preliminary cost effectiveness analysis was conducted first for: (A) a Supply to Tokyo scenario, and second for (B) a Local Demand Generation scenario. Both renewable energy exodus scenarios were found to have merit in promoting a sustainable future. [ABSTRACT FROM AUTHOR]

For the utilization of renewable energy from sources widely distributed in low-density non-urban areas the grid augmentation for its transmission to urban areas of high population density is often discussed under the premise that the present demand distribution remains invariant. Instead of grid augmentation, this study examined an alternative option of creating a power demand close to renewable sources and inducing population movements (i.e., Renewable Energy Exodus). First, the capacity of renewable energy to maintain populations in hilly and mountainous farming areas of Japan was evaluated from two perspectives: Task (1) a challenging nationwide balance based on possible energy demand saving scenario for the future, and Task (2) a conservative nationwide balance based on the current per capita energy demand and on the region-by-region generation–consumption matching concept. Because Task (2) indicated that Hokkaido, the northern-most island, has a huge capacity, Task (3) was conducted for Hokkaido by examining both energy balance and economic evaluation including job creation for the following two scenarios: (A) a supply to Tokyo scenario and (B) a local demand generation scenario, keeping the same conservativeness as Task (2) by using the current data for energy consumption per capita. The nationwide Renewable Energy Exodus estimates gave 48 million people for Task (1) (with the future per capita energy demand) and 10 million people for Task (2) (with the current per capita energy demand and region-by-region self-sustained balance), respectively. For Hokkaido Task (3) (with an additional economic assessment) gave 1 million people. The Renewable Energy Exodus concept combined with the green economy promotion was found to have a significant merit for a sustainable future of countries like Japan where economic and social disparities are serious between urban areas and non-urban areas. [ABSTRACT FROM AUTHOR]