Journal of Japan Society of Civil Engineers, Ser. G (Environmental Research)
Online ISSN : 2185-6648
ISSN-L : 2185-6648
Volume 76 , Issue 5
Showing 1-50 articles out of 57 articles from the selected issue
Global Environment Engineering Research, Vol.28
  • Kei NAKAGAWA, Shogo TAKEMORI, Hiroshi ASAKURA
    2020 Volume 76 Issue 5 Pages I_1-I_8
    Published: 2020
    Released: January 18, 2021
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     Groundwater pollution with nitrate is a serious environmental challenge. The nitrate levels in the study area have been exceeding the acceptance levels in Japan. In the most cases, a batch test is applied to determine the pollutant content in the soil. In this study, the elution amount of nitrate was evaluated with the breakthrough curve obtained from the column experiment, and the validity of the batch test was examined. As a result, it was found that the solid-liquid ratio of 1:3 could be sufficiently eluted for nitrate in the column experiment. The results of the three elution tests; the column test, the batch test, and the stirring test, showed that almost same amount of nitrate eluted.

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  • Takashi YUASA, Ryo MATSUMARU, Toshiya ARAMAKI, Gaku MANAGO, Kyoko SHIB ...
    2020 Volume 76 Issue 5 Pages I_9-I_18
    Published: 2020
    Released: January 18, 2021
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     In recent years, it has been pointed out that the conditions of Inle lake relevant to water quality has been deteriorated. To evaluate water pollution factors from a macroscopic viewpoint, pollution loads from the watershed were estimated by adopting “pollutant load factor method.” As a result, according to estimation of total pollution loads for Inle Lake, the amount of COD came to be 29,000 kg/day, TN for 20,100 kg/day, and TP for 1,820 kg/day. The results indicate that the non-point source loads were overwhelmingly large. Comparing these results with the main lakes in Japan, Lake Biwa contains the highest level of COD, following by Lake Inle and Lake Kasumigaura. While Lake Inle has the highest concentration of TN and TP. Based on the results, implementing solutions such as controlling the domestic pollution load and proper fertilization in the floating garden should be prioritized. In this study, the measures, clarified the effectiveness of the pollutant load factor method for assessing the macro pollution factors and considering the prior measures to mitigate the water pollution for Inle Lake, are applicable to the developing countries.

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  • Kei NUKAZAWA, Shu FUKAGAWA, Yoshihiro SUZUKI
    2020 Volume 76 Issue 5 Pages I_19-I_26
    Published: 2020
    Released: January 18, 2021
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     Environmental DNA (eDNA) method, a novel technique for precise and expeditious biological surveillance, has been widely used for monitoring population dynamics and safeguarding wild animals such as rare species. However, eDNA has rarely been applied to turbid water environments, and thus, surveillance method for turbid water has not been established. In this study, we explored applicability of environmental DNA method to rivers under various turbid conditions targeting Cyprinus carpio. Turbid water collected from the three rivers bearing different land-use in the catchments was processed based on the two different filtering methods either using a grass fiber filter (pore size = 0.7 µm) or prefilteration (20 µm) before processing with the grass fiber filter. Under highly turbid conditions, conventional grass fiber-based filtering method could not process 1 L even using two filter papers for many samples while it exhibited greater concentration of eDNA than the prefilteration method. None of suspended solids or ash free dry mass was associated with eDNA concentration.

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  • Kazuma MATSUSHITA, Katsuhide YOKOYAMA, Kouji NAKAYAMA, Makoto HATAKEYA ...
    2020 Volume 76 Issue 5 Pages I_27-I_32
    Published: 2020
    Released: January 18, 2021
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     A new saltmarsh was created due to land subsidence by the Great East Japan Earthquake, 2011 and erosion by the following tsunami attack. Water level, salinity and dissolved oxygen (DO) were measured from 2012 to 2019 with the time interval of 10 or 20 minutes in this saltmarsh, and variation of salinity and DO were discussed. Although maximum salinity level reached 32 and it does not change every year, lower level of salinity decreased gradually. Since the subsided land rises by 5 cm every year, seawater was difficult to intrude into the estuary during rainy season and storm discharge flow into the saltmarsh increased every year. DO increased rapidly in the morning (2.8 – 3.6 mg/L/h) and it decreased rapidly in the afternoon (3.4 – 4.3 mg/L/h), then is decreased gradually from night to the next morning (0.4 – 1.1 mg/L/h). DO in the surface water became supersaturated during daytime. This is caused by production and consumption by aquatic plant. DO in the bottom water became anoxic at night and for several days after rainfall. The reason is that the vertical mixing of bottom salt water was regulated due to wrapping by freshwater in addition to the consumption by aquatic plant.

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  • Yanni HAN, Hiroshi SAKAI, Akira KOIZUMI, Chisato NISHIMAGI, Hiromi IWA ...
    2020 Volume 76 Issue 5 Pages I_33-I_42
    Published: 2020
    Released: January 18, 2021
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     Maintenance of the Watershed Forest in the upper stream of the Tama River is necessary for supply of drinking water with safety and tasty. In this study, pollution load from the watershed, where water supply forest is conserved, was evaluated. GIS software was used to grasp the land use of each basin. Its information was provided to calculate unit pollution load for total nitrogen, total phosphorus, and COD. Annual pollution load was calculated for each basin based on water quality monitoring data. To subtract pollution load from point and non-point sources other than forest, land use of the basin, domestic waste water, and fishery effluent were considered. Calculated unit pollution load from the forest was compared with values in database from other watersheds in Japan. Compared with other watershed, unit pollution load was similar or lower. As more than 96 % of target area is covered by forest, calculated value of unit pollution load was further divided by annual rainfall, to compare the relations among unit pollution load index, vegetation and area of watershed forest.

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  • Hitoshi TANAKA, Nguyen Xuan TINH, Nguyen Trong HIEP
    2020 Volume 76 Issue 5 Pages I_43-I_48
    Published: 2020
    Released: January 18, 2021
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     Nobiru Coast, which is 2.8 km long coast located in Miyagi Prefecture, Japan, is a well-known coast because of high sediment deposition rate. The predominant littoral drift of this coast is from east to west. The sediment deposit at the western end causes significant effect on the aquaculture in Matsushima Bay which is located on the right of Miyato Island, due to closure of a channel connecting open sea and Matsushima Bay. Due to the impacts of the 2011 tsunami, the coastal areas were seriously damaged and the channel was opened again. According to the shoreline analysis on Nobiru Coast at decadal to centennial scales including the 2011 tsunami impact using aerial and satellites images, the longshore sediment transport rate on Nobiru coast from 1964 to 2006 reduced about 60% compared to the one in the previous period. However, that increasing rate does not change much in the period after the tsunami although severe damages could be observed. The present amount of sediment corresponds to that during early 1980s. Therefore, it can be roughly estimated that the blockage of the Katsugigaura Channel due to the sediment deposition on the west end of the coast will take place again in the future around 2040s.

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  • Daisaku SATO
    2020 Volume 76 Issue 5 Pages I_49-I_54
    Published: 2020
    Released: January 18, 2021
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     Atoll islands has resources of fresh water under the ground which called freshwater lens. Freshwater lens has been used traditionally by residents of island, however, the rapid urbanization and salinitation changed the freshwater lens as unusable resources. this study conducted that the numerical simulation on formation of freshwater lens forcused on the width of island, recharge rate and influence of tidal change of water surface. the results revealed that the volume of freshwater lens increase with direct proportion by recharge rate. Additionally the volume of freshwater lens increased exponentionally by width of island. It was estimated that the potential volume of freshwater lens formed Fongafale island of Funafuti atoll provides residents resource of freshwater for 40 to 90 years. Tidal change influenced to salinity concentrtion and shape of the edge of freshwater lens but the influence is locally.

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  • Teerawat RAM-INDRA, Yasuto TACHIKAWA, Kazuaki YOROZU, Yutaka ICHIKAWA
    2020 Volume 76 Issue 5 Pages I_55-I_63
    Published: 2020
    Released: January 18, 2021
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     This study investigates the applicability of bias correction for runoff generation data from AGCM3.2s over the northern part of Thailand. A land surface model generates 20 years of reference runoff data after being carefully calibrated and validated by observation discharge to ensure the performance of the runoff reference data. Two simple bias correction methods, namely linear scaling factor and empirical quantile mapping bias correction, were tested to reduce biases. The linear scaling factor method performs better in reducing bias than the empirical quantile mapping in the monthly mean of runoff generation for each grid and river discharge. In contrast, both bias correction methods are not effective in adjusting to the quantile of monthly river discharge. This study provides an understanding of the characteristics of biases in GCM runoff and leads to the development of new bias correction methods.

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  • Haruki MINEDA, Kei NUKAZAWA, Shogo NAKAO, Yoshihiro SUZUKI
    2020 Volume 76 Issue 5 Pages I_65-I_74
    Published: 2020
    Released: January 18, 2021
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     To date few studies have tackled flow alterations by withdrawal for hydropower generation and flood control at a river network scale. Here we applied a distributed hydrological model to the Omaru River catchment in southwest Japan to assess longitudinal patterns of altered flow regimes by dams and weirs, and mitigation by inflow of discharges used for hydropower generations and tributaries. Runoff analyses were performed either for the cases where the boundary conditions of dams and weirs (e.g., dam/weir outflow) was included or not in the model. Subsequently, the extents of the alternations were quantified by the ratio of the flow regime metrics between them. Runoff analyses were found to be highly predictive throughout the three years (NS = 0.909-0.962). Although the discharge used for hydropower generation well mitigated the alternaions under higher flow condition; 25 percentile of annual flow (Q25), the mitigation effects were insufficient under median (Q50) to 97 percentile low flow (Q97) conditions. The mitigation effects by tributaries tended to increase in proportion to the increase in inflow, specifically in case of the flow regime metrics with lower flow rate. This suggests that the mitigation effect is more dependent on discharge than on spatial location of the inflow.

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  • Nguyen Quang DUC ANH, Hitoshi TANAKA, Nguyen Xuan TINH, Nguyen Trung V ...
    2020 Volume 76 Issue 5 Pages I_75-I_80
    Published: 2020
    Released: January 18, 2021
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     This study presents the sand spit evolution at two typical tidal inlets in central Vietnam by using the long-term remote sensing image data. The sand spit geometric characteristics and the elongation rate, especially sand spits breaching phenomena for the Ken Inlet in Ha Tinh province and Phan Inlet in Binh Thuan province were quantified. Sand spit elongation at Ken Inlet was at a stable rate of about 65 m/y. Whereas, the sand spit elongation rate in Phan Inlet developed very quickly with an average speed of about 185 m/y. In addition, three breaching occurrences of the sand spit in Phan Inlet have been observed in the periods of 1990-1991, 1998-1999, and 2014-2015. The longshore sediment transport rates along the Phan Inlet were almost constant during these three periods. The averaged longshore sediment transport rate at Phan Inlet were estimated around 145,000 m3/y, while Ken Inlet was about 135,000 m3/y.

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  • Ryosuke NOYORI, Kazuyoshi SOUMA, Takuya TAKAYAMA, Jun MAGOME, Hiroshi ...
    2020 Volume 76 Issue 5 Pages I_81-I_88
    Published: 2020
    Released: January 18, 2021
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     Recently, heavy localized rainfall has caused serious problems in Japan. Furthermore, anthropogenic sensible heat enhances such rainfall. Therefore, weather forecasts that include details on anthropogenic heat distribution across Japan are required. In this study, we estimated detailed anthropogenic heat distributions using statistics and geographic system information (GIS) data that are available nationwide. Data on anthropogenic sensible heat, anthropogenic latent heat, and warm drainage exhaust heat were obtained at a spatial resolution of approximately 1 km across Japan. Anthropogenic heat was estimated for residential, business, industrial and automotive components in the country. We compared the annual total anthropogenic heat for each prefecture with the annual final energy consumption obtained from statistics; the obtained correlation coefficient was 0.88. Therefore, we conclude that the estimated anthropogenic heat corresponds to the energy consumption in each prefecture. In future studies, the estimated anthropogenic sensible heat distribution should be introduced into numerical meteorological models (cloud-resolving meteorological models) used for short-term predictions.

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  • Yuya SEKI, Tomoko HASEGAWA, Shinichiro FUJIMORI
    2020 Volume 76 Issue 5 Pages I_89-I_95
    Published: 2020
    Released: January 18, 2021
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     There is a concern that the global warming will cause massive flood damage, but other literature does not assess the impact of floods on food consumption and hunger risks.The purpose of this paper is to clarify the impact of global floods on food consumption and hunger risk through changes in crop yields.As an improvement plan, we calculate the amount of food stockpiling required to reduce the impact. As a method, we will calculate food consumption and hunger risks using the CGE model. Then aggregate the results into 17 regions around the world to evaluate the impact of floods. As a result, the world population at risk of hunger will increase by about 11million (7.8 million to 13 million due to model uncertainty) and food calorie intake will decrease by 6.6 kcal/person/day (5.3 to 8.6 kcal/person/day) in 2030. Developing countries will be suffered severe damage. In Africa, the number of hungry people increased by about 5.5 million (340 to 590 million) and food calorie intake will decrease by 14 kcal/person/day (10 to 14 kcal/person/day). The amount of food stockpiling will be required 1.9 million tonnes (1.4 to 1.9 million tonne).

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  • Osamu NISHIURA, Shinichiro FUJIMORI, Ken OSHIRO
    2020 Volume 76 Issue 5 Pages I_97-I_107
    Published: 2020
    Released: January 18, 2021
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     Because of expected increases of GHG emissions due to population and economic growth, Asia is an important region for climate change mitigation. It's required to investigate the GHG reduction measures to achieve the 1.5°C goal set out in the Paris Agreement and to assess its economic impact. This study used an economic model to estimate energy system changes and economic impacts due to GHG emissions reductions up to 2050 in eight Asian countries and revealed the emission reduction measures in each country. Moreover performing multiple regression analysis based on the model calculation results, an estimation formula to explain the GDP loss was modeled and the factors of economic impact were analyzed. The results of the economic model show that the use of BECCS plays a significant role in all countries in the emission reduction based on the 1.5 °C goal. The estimation formula shows that the growth rate of GHG emissions, the share of energy in household expenditures, and GDP per capita would influence the GDP loss due to GHG emission reduction.

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  • Ryosuke ARAI, Yasushi TOYODA, Masamichi OHBA, Takahiro SATO, So KAZAMA
    2020 Volume 76 Issue 5 Pages I_109-I_119
    Published: 2020
    Released: January 18, 2021
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     According to previous study, climate change can increase extreme snowmelt runoff caused by rain-on-snow (RoS) in winter in Japan Sea region. This study aims to evaluate the impact of climate change on snowmelt runoff caused by RoS on a basin scale. Targetting on Shogawa river basin within Japan Sea region, we applied database of climate prediction (d4PDF) to hydrological model which can consider snowfall and snowmelt processes through correcting a few climate indices (e.g., temperature) as a function of elevation data. While the global warming has a possibility to decrease the averaged snowmelt runoff, our result indicated that the peak flow of snowmelt runoff in future climate will be larger than that of current climate. Similarly, we found that the peak flow in RoS will become severe in future climate. Additionally, our result indicated that the severe peak flow in RoS will appear in December to March in future climate, which was rarely observed in current climate.

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  • Makoto TAMURA, Kosuke SEKINE, Ying WANG, Yuki YASUHARA, Yoko IMAI, Yok ...
    2020 Volume 76 Issue 5 Pages I_121-I_127
    Published: 2020
    Released: January 18, 2021
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     The present paper examines farmers’ perceptions of climate change and their current and potential future measures for adaptation. We conducted a questionnaire survey for farmers in Joso city, Ibaraki prefecture in December 2019 and examined climate change impacts and the farmers’ adaptations using both statistical and geographical analyses.

     It was found that 1) more than 80% of respondents had experienced some damages due to climate change, such as decreased yield, poor growth, and an increase in insect pests; 2) their current adaptations included water treatment and the use of agrochemicals including pesticides; and 3) potential future adaptations included changing the cultivars, the type of crop, and the crop calendar. In addition, factors affecting adaptive behaviors included experiences of damages due to climate change, awareness of climate change, and knowledge of measures for adaptation.

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  • Ryouichi WATANABE, Shinichiro FUJIMORI, Tomoko HASEGAWA, Ken OSHIRO
    2020 Volume 76 Issue 5 Pages I_129-I_140
    Published: 2020
    Released: January 18, 2021
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     Crop yields would be affected by tropospheric ozone induced by air pollutants along with climate change. We calculated effects of tropospheric ozone on crop yields based on air pollutants emission scenarios. The results show that an implementation of stringent climate policy reduces future tropospheric ozone and improves global crop yields by 1%. At the meantime, this co-benefit is equivalent to 30% of the direct climate change impacts avoided by the climate policy. Regionally, the improvement rates can be more than three times of the global mean number (e.g. the Middle East, North Africa and Asia). It implies that stringent climate policy would be important in the context of the global sustainable development goals for the regional development.

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  • Tao YAMAMOTO, So KAZAMA, Yoshiya TOUGE, Tsuyoshi TADA, Takeshi YAMASHI ...
    2020 Volume 76 Issue 5 Pages I_141-I_150
    Published: 2020
    Released: January 18, 2021
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     This study evaluated the impact of flood damage caused by climate change and the effects of mitigation and adaptation measures. Using the two-dimensional unsteady flow model and the Flood Control Economic manual (by Ministry of Land, Infrastructure, Transport and Tourisum), the inundation depth and economic damage were calculated. In order to estimate the flood damage at the end of the 21st century, the rainfall in the future climate was obtained using 5 GCMs, and the future inundation depth and economic damage were obtained using these as input values. In addition, we focused on land use control as an adaptation measure, and examined the effect of reducing the amount of damage and the cost-benefit ratio (The social discount rate is 4.0%). It was estimated that the mitigation from RCP8.5 to RCP2.6 at the end of the 21st century would reduce the expected annual flood damage by 246.5 billion yen / year. It was estimated that adaptation measures by land use control, which regulates areas flooded by 3 m or more during floods with a return period of 200 years, would reduce expected annual damage by 26% in the current climate. The estimated cost-benefit ratio was 0.684 for the mitigation measures, while the cost-benefit ratio for land use control was estimated to be about 0.019.

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  • Makoto UMEDA, Rikushi YASUMATSU
    2020 Volume 76 Issue 5 Pages I_151-I_157
    Published: 2020
    Released: January 18, 2021
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     In recent years torrential downpour occurs frequently due to the effect of climate change. Because of this, excess of high turbidity in reservoirs and long term persistence of turbidity has recently been regarded as a serious problem. Behaviour of suspended sediment(SS) is highly influenced by characteristics of reservoirs and of its catchments, such as turn over rate and erosion severity. Hence, this study conducted future prediction of turbidity in 29 reservoirs in Japan by applying 1-dimension hydraulic model. Results showed that change in stratification period causes increase of SS concentration in outflow during snowmelt period. Furthermore, we revealed that change in inflow due to change in precipitation will result in substantial increase in SS in outflow in the future.

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  • Ke ZHOU, Toshiya ARAMAKI, Hidetoshi KITAWAKI
    2020 Volume 76 Issue 5 Pages I_159-I_165
    Published: 2020
    Released: January 18, 2021
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     A questionaire survey on public awareness of source separation was conducted in the city of Changsha, the capital of Hunan province in the Southern China. Respondents of the survey were collected in two ways, by a face-to-face interview on street and by SNS. In the SNS survey and the face-to-face survey, 235 and 117 samples were collected.

     As a result, goal intention has a highly correlation with environmental risk recognition and responsibility attribution in both surveys, but the factors related to behavior intention are different according to the way of the survey. For behavior intention, social norm, goal intention, and cost benefit recognition are affected according to the attribute of respondents in each survey. In respondents with higher educational background, the recognition of environmental risk tends to connect with goal intention, and social norm tends to connect with behavior intention. Those results will be useful for examining what kind of measures are effective depending on the attributes of the target group when enhancing the goal intention or behavior intention of source separation.

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  • Motoko KOSUGI, Kenshi BABA, Mitsuru TANAKA
    2020 Volume 76 Issue 5 Pages I_167-I_176
    Published: 2020
    Released: January 18, 2021
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     The aim of this study is to subdivide respondents into some segments according to the characteristics of their attitudes toward global warming and compare segments by using online questionnaire survey data for 2017 and 2020. As a result, we found 5 segments in 2020 survey data; Alarmed who have a high risk perception and are actively engaged in countermeasures (20%), Disengaged who are less interested and do not have a clear opinion (33%), Doubtful who are skeptical and do not feel the need for dcountermeasures (6%), Acquiescence who have a tendency to agree with all questions (10%) and Concerned who have milder attitudes than Alarmed and no action (30%). The first four segments have been shown to exist as they did three years ago. On the other hand, people with a strong tendency to answer all questions negatively, but concerned are newly extracted. Disengaged is the most important target for information provision because of the largest size. At the same time, the newly extracted Concerned is also important to consider an approach that encourages countermeasure action toward global warming. Because they occupies 30% of the respondents and their interest and risk perception are high.

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  • Tadahiro OKUYAMA
    2020 Volume 76 Issue 5 Pages I_177-I_186
    Published: 2020
    Released: January 18, 2021
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     The purpose of this study is to explore social values of natural environments by measuring an amount of reducing a migrant subsidy supplied for people who hope to immigrate from an urban city to a rural city. The survey searches residents who live in 21 large cities of Japan and hope to migrate, requiring them to answer their desired amounts of subsidies (willingness-to-accept value; WTA) and important residential environments (policy variables) if migrated. Estimation results indicate that policy variables are categorized as i) the ones of reducing subsidy amounts, and ii) not reducing. Benefit calculations show a base line WTA value (BWTAV) calculated by using ii is about 590 thousand yen per once; Housing environment improvements is most effective, reducing about 52 thousand yen, then natural environment protections reduce about 33 thousand yen from BWTAV, respectively.

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  • Hiroto SHIRAKI, Makoto SATO, Kazuma MURAKAMI
    2020 Volume 76 Issue 5 Pages I_187-I_195
    Published: 2020
    Released: January 18, 2021
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     This study conducted a questionnaire survey to understand the actual situation of the introduction of electric vehicles (EVs) in companies and to identify the factors that affect the willingness to introduce EVs in companies. Results of questionnaire survey shows that there is a significant relationship between the introduction of EVs and the acquisition of ISO14000 series. The results of structural equation modeling shows that the evaluation of EV’s function has the largest impact on the willingness to introduce EVs. In addition, the execution of corporate social responsibility and the evaluation of the effect to improve company image by the introduction of EV are significantly affected the willingness to introduce EVs in companies. Multi-group covariance structure analysis shows that impact of the evaluation of charging station has significantly larger in the group that used company cars frequently. Further improvement of power supply function of EVs and publicity of charging stations would be effective in promoting EVs in companies.

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  • Yoshitaka SAKATA, Takao KATSURA, Katsunori NAGANO
    2020 Volume 76 Issue 5 Pages I_197-I_204
    Published: 2020
    Released: January 18, 2021
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     This study demonstrated an inquiry survey for local governments of populations over 50 thousand in Japan and all governments in Hokkaido Island to analyze present situations and decision factors for the installation of ground source heat pump systems in public buildings. The number of answered governments reached at 443 for the former governments and 117 for the latter, respectively. About 90 % of the answered governments know “what a ground source heat pump system is” more and less, but only about 10 % have installed the systems. The former and latter governments commonly responded high initial costs as the primary issue for the installation, as suggested by previous researches. As secondary issues, the former requested to standardize how to design the system, and the latter governments to evaluate the contribution to the environments. Linear discriminate analysis indicated that the decision factors in the former governments were the degree-day for heating, the number of affiliated companies in the geo-heat promotion association, and the population, and in the latter governments were the population, its increase during five years, and environmental activity in the national policy. Finally, this study derived approximated power functions of capital costs for borehole heat exchangers and heat pumps, respectively, in the least square based on the inquiry survey data, as references for practical design and planning of ground source heat pump systems in public buildings.

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  • Yoko IMAI, Makoto TAMURA, Yuji MASUTOMI, Kenshi BABA
    2020 Volume 76 Issue 5 Pages I_205-I_210
    Published: 2020
    Released: January 18, 2021
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     In this study, we analyzed farmers’ perceptions of climate change and whether they intend to adapt to such changes. A web-based survey was designed in February 2019 to investigate the perceptions of Japanese farmers who produce rice, wheat, or vegetables regarding the potential impact of climate change on their farming activities. Responses were received from 426 farmers (358 men, 68 women). As a result, 215 farmers (50.5%) responded that they had experienced damage attributed to global warming. When asked about their risk perceptions of various types of damage and disasters, “typhoons”, “heat waves/intense heat”, “earthquakes”, and “heavy rainfall” were considered to be the most serious hazards, in order. Regarding the implementation of adaptation measures to reduce these threats, 27.0% of the farmers have implemented practical measures to prevent crop damage due to global warming. Our findings suggested that, although the farmers were less aware of the technical terminology related to climate change in Japan, those farmers who had previous experience with damage that may have been attributed to global warming, and those who had a higher risk perception of extreme weather, were proactive in implementing adaptation measures.

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  • Hiromichi SUZUKI, Yosuke SAITO, Takashi HAMADA, Seiki KAWAGOE
    2020 Volume 76 Issue 5 Pages I_211-I_220
    Published: 2020
    Released: January 18, 2021
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     In this study, we attempted to develop information that can be used as an adaptation measure to prepare spatio-temporal sediment disaster prone areas risk information according to maximum heavy rainfall from the past to the future forecast. The target area is Nagano Prefecture. The risk information of the warning area was derived using the probable maximum precipitation as the maximum rainfall. In addition, we have developed probability risk map from the past to the future of the caution zone obtained by using slope failure probability model as spatio-temporal sediment disaster prone areas risk information. As a result, The sediment disaster prone areas risk information has been developed in each climate condition (present, near furture and future), and the quantification of risks has been attempted the time change according to local area. Information on local governments was obtained to need to support of counter measure. In addition, resulting output data was suggested to use a case study of adaptation measures.

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  • Naoko KUMANO, Makoto TAMURA, Tomomi INOUE, Hiromune YOKOKI
    2020 Volume 76 Issue 5 Pages I_221-I_231
    Published: 2020
    Released: January 18, 2021
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     Sea level rise due to climate change poses a serious threat to human populations in coastal areas. Consequently, it is important to consider the potential economic risks and the cost of adaptation within the context of climate change. To this end, coastal regions can be protected more efficiently and economically by employing adaptation measures that combine mangrove afforestation (green infrastructure) and dyke construction (grey infrastructure) in areas considered to be at risk of inundation and flooding. The authors analyzed the costs of gray and green infrastructure developments at locations in Vietnam and the Philippines that differed with respect to population distribution and urban/rural status. However, there are areas where combinations of green and grey infrastructures have been employed along the same coastline. This paper therefore examined the assumptions underlying the implementation of specific inundation protection measures, as well as the costs associated with dykes and multiple protection measures along the same coastline. The findings showed that multiple protection measures that incorporate mangrove forests can reduce the number of dykes required and costs of adaptation.

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  • Kenshi BABA, Tomoko OGUSU, Taiko KUDO, Minoru YOSHIKAWA, Hiroki OHNISH ...
    2020 Volume 76 Issue 5 Pages I_233-I_242
    Published: 2020
    Released: January 18, 2021
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     This paper reports on nationwide trends on utilization of scientific evidence in environmental departments in local governments via analyzing database which we have built based on the administrative documents, interviewing and questionnaire.The main results demonstrate as follows; i) Collecting scientific evidence by their own budget is quite rare and it depends the governments’ subsidiary enterprise to some extent. ii) Scientific evidence which is more detailed in space and time scale is getting used more than ever and the tendency will be spurred on. iii) It is important for climate change adaptation local centers to undertake the roles of interpreting for scientific evidence and sharing knoledges of local staleholders and scentists.

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  • Ken OSHIRO, Shinichiro FUJIMORI, Tomoko HASEGAWA, Osamu AKASHI
    2020 Volume 76 Issue 5 Pages I_243-I_252
    Published: 2020
    Released: January 18, 2021
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     The Paris Agreement climate goals would require large scale transitions in global energy investment from fossil based infrastructures to low-carbon energy systems. In this regard, Asian regions would play an important role in the global energy system transformation. In the context of Japan’s development strategies, it would be important to estimate investment needs in Asia, associated with the near-term ambition of the national low-emission targets. Here we present the energy investment needs and their changes with enhanced near-term mitigation targets in Asian countries using a global energy system model. Our results suggested that delayed mitigation actions in the near-term and associated rapid transition between 2030 and 2050 would increase the long term energy investment. Without enhancing the 2030 emission reduction target, energy investment would be doubled by 2050 relative to the global cost optimal 2°C scenario. Particularly, coal power plants without carbon capture and storage are stranded by 2050. Without enhancing the near-term ambitions in Asian countries, the stranded capacity of coal power plant is doubled by 2050 relative to the global cost optimal scenarios for achieving the global 2°C goal.

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  • Naoko HIRAYAMA, Kanon YAMASHITA, Tomomi BABA, Kentaro TAKI
    2020 Volume 76 Issue 5 Pages I_253-I_260
    Published: 2020
    Released: January 18, 2021
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     Recently, improvement of community’s capability for disaster prevention and creation of flood hazard map has been promoted by local governments because of more frequent occurrence of large-scale floods and landslide disasters. This study carried out the questionnaire survey to every residents’ association in Shiga prefecture to clarify the relationship between flood damage mitigation activities in the community and creation of flood hazard map by residents. Statistical analysis was performed based on cross tables of 2248 responses.

     As a result, the residents' associations which had created hazard map by themselves tended to carry out patrols of vulnerable points, community leaders’ meetings, stacking sandbags, confirmation of residents’ safety, and evacuation guidance when flood risk becomes high. Among such associations, a residents' association tended to carry out patrols of vulnerable points, communication with for flood prevention team, community leaders’ meetings, and confirmation of residents’ safety, if the associations had designed evacuation routes and refuges in its creating process of HM.

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  • Soma SAITO, Ayano MATSUMOTO, Satoshi WATANABE
    2020 Volume 76 Issue 5 Pages I_261-I_267
    Published: 2020
    Released: January 18, 2021
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     This study estimated the relationship between temperature and precipitation and snow depth based on observations by the Japan Meteorological Agency, and clarified the characteristics of low snow depth in the year 2020, which was among the lowest in many regions. Although 2020 was a low snowfall year, the trends in temperature and precipitation, which are considered to be the background, differed across regions. Hokkaido had a record low rainfall and Honshu had a record high temperature. This is consistent with the trend of correlation between temperature or precipitation and snow depth in each region. In addition, the frequency of occurrence of temperature and precipitation that was equivalent to those in lowest snow depth was estimated for the situation under 2°C and 4°C warming using large ensemble dataset. In particular, it was found that the frequency of temperature that is equivalent to the case of historical lowest snow depth may occur as often as once every one to two years under a 2°C warming.

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  • Jean Margaret R. MERCADO, Akira KAWAMURA, Hideo AMAGUCHI, Christabel J ...
    2020 Volume 76 Issue 5 Pages I_269-I_276
    Published: 2020
    Released: January 18, 2021
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     Monitoring & evaluation (M&E) of the integrated flood risk management (IFRM) in Metro Manila has not been carried out since its inception. There is no monitoring agency in charge of the M&E activities for the adaptation to IFRM in the Philippines, and this resulted in the lack of baseline information and measurable indicators to be used for M&E activities. This study attempts to conduct an M&E of the IFRM in Metro Manila. The performance for the IFRM of each municipality in Metro Manila was appraised by the officers-in-charge of the local government offices related to disaster risk reduction. The qualitative judgments from the respondents were evaluated using a multi-criteria analysis approach based on priority ranking methodology to quantify the appraised performance for IFRM. The results show that several municipalities in Metro Manila are performing very well but with recognized limitations, and at least three municipalities requires serious attention because all components of the IFRM in these municipalities are gravely lacking. The results of the study can be used as baseline information for the M&E activities on IFRM in Metro Manila. The methodology proposed in this study is simple and systematic that can guide decision-makers and practitioners in evaluating the performance for the IFRM.

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  • Akira TOMIGASHI, Youhei UCHIDA, Kazuhiro SHIMADA, Gaurav SHRESTHA, Tak ...
    2020 Volume 76 Issue 5 Pages I_277-I_287
    Published: 2020
    Released: January 18, 2021
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     At the Industrial Research Institute of Ishikawa Prefecture located in the central part of the Kahoku plain, the thermal response tests (TRTs) were performed two times in snowfall season and non-snowfall season. Appropriate data could not be obtained from the TRT conducted during the snowfall season . This is considered to be due to the groundwater pumping for the snowmelt system that operates during snowfall. The demonstration results of the ground source heat pump (GSHP) system show good operation results for both cooling and heating. A simple verification analysis of underground temperature during the system demonstration resulted in high reproducibility when apparent thermal conductivity obtained from TRT data performed in non-snowfall season was considered. From these results, the GSHP system is thought to have good potential for public facilities and offices in the Kahoku plain. The important points to be considered for introducing the system in the Kahoku Plain are performing the thermal response test in the non-snowfall season, and estimating the effective thermal conductivity from geological information when TRT cannot be carried out in the non-snowfall season.

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  • Shun SHIMOYAMA, Akira TOMIGASHI, Daichi SATO, Shohei KANEKO, Rei SATO, ...
    2020 Volume 76 Issue 5 Pages I_289-I_299
    Published: 2020
    Released: January 18, 2021
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     In order to continuously use the cold energy of the underground space at the Oya stone mining sites, it must be properly predicted the temperature rise of the underground space. Forecasting by numerical simulation requires thermophysical properties of Oya stone. However, Oya stone has different lithofacies depending on the location, and the thermophysical properties show higly uneven distribution. Accurate future prediction requires evaluation of the spatial thermophysical property distribution in the area. Therefore, we proposed a simple evaluation method of thermophysical properties based on an in-situ survey method using underground space and one-dimensional unsteady heat conduction analysis. The in-situ test data were obtained from the previous test performed by Utsunomiya City. As a result, the reproducibility calculation of the test using the thermophysical properties by the existing literatures were well reproduced. Therefore, the usefulness of the proposed method was confirmed. In addition, the tasks to be solved for future practical application were grasped.

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  • Magsar AMGALAN, Toru MATSUMOTO, Tarzad ULAANBAATAR, Nyamosor NANDINTSE ...
    2020 Volume 76 Issue 5 Pages I_301-I_309
    Published: 2020
    Released: January 18, 2021
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     Water resources are dramatically sensitive to climate change in Mongolia. In this study, the authors aimed to evaluate the impact of climate change on Ogii Lake by using the estimated daily evaporation from the lake and the variation in the surface area of the lake. Ogii Lake is located in the eastern region of Arkhangai Province, central Mongolia, which registered as an International Ramsar Convention site in 1998. Evaporation was estimated from 1986–2019 using the energy-budget method based on ERA5 reanalysis climate data. Landsat–8 operational land imager (OLI) satellite remote sensing images were used to estimate the monthly lake water surface area changes from 2013–2019. The results showed that increases in evaporation since 1995 exceeded the precipitation in most years. Comparing to 1989 total annual evaporation from the lake increased by 32.4 mm in 2019, which is 1.1 times higher than evaporation in 1989. However, during the period from May to October (2013–2019), monthly average lake water surface area has increased steadily, while the evaporation accounted higher than the precipitation. Based on the results, the authors assume that groundwater may strongly impact the water balance of Ogii Lake.

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  • Shingo TOYODA, Yuji KUWAHARA
    2020 Volume 76 Issue 5 Pages I_311-I_318
    Published: 2020
    Released: January 18, 2021
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     According to the 5th IPCC Assessment Report, the global average sea level is expected to rise owing to the global warming effect. For the worst-case warming scenario (RCP8.5), the average sea level is expected to rise up to 0.82 m. Therefore, global coastal dike information is important to estimate of inundated area due to storm surge, tide level and sea-level rise. Therefore, the precision of the simulation results was inspected at Ise Bay, Tokyo bay, Viet Nam and Chinausing global coastal dike information. The results of this study are as follows: 1) Global dike information was generated on a global scale except for the Arctic Ocean coast and Antarctica. 2) Based on the comparison with a hazard map and inundation experience map, a reasonable validity of the flood simulation in Tokyo bay and Ise Bay were indicated. 3) It was found that the global dike information can be used for a prediction of inundated areas across Japan. 4) Features of inundated areas were investigated by using land use information in Viet Nam and China.

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  • Hideo AMAGUCHI, Akira KAWAMURA
    2020 Volume 76 Issue 5 Pages I_319-I_325
    Published: 2020
    Released: January 18, 2021
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     In the low-impact development of urban areas, storm runoff control drainage systems combining land drainage channels and rainwater regulating ponds are developed to reduce the load on rainwater runoff. In order to confirm the effect of storm runoff control drainage system, a method for modeling a detailed rainwater runoff process using urban landscape GIS data that can faithfully represent a complicated urban structure. In this study, we constructed a urban landscape GIS considering the rainwater runoff control drainage system in Augustenborg area, and showed the effects of green roof and runoff control type open channel by simulation.

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  • Gen MACHIDA, Kazutoshi OSAWA, Hiroyuki MATSUI
    2020 Volume 76 Issue 5 Pages I_327-I_334
    Published: 2020
    Released: January 18, 2021
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     In Okinawa, Japan, soil erosion at sugarcane fields is a serious problem. Turbid water due to soil erosion flows into the coastal area has and cause a great negative impact on coral and other aquatic ecosystems. In this study, we analyzed the sediment discharge from sugarcane fields in Okinawa by using the Water Erosion Prediction Project, WEPP to improve the prediction and the control of the soil erosion. First, the accuracy of WEPP calculation was verified under several conditions. In each calculation, the soil erodibility was represented by the coefficient which reflects the soil properties. From the comparison between the field study and WEPP calculations, the high accuracy of coefficients which are identified from laboratory experiments was verified. Next, some virtual fields were set up for different sugarcane cultivation methods. The results for each cultivation methods showed that the amount of sediment discharge was large in the order of summer planting, spring planting, and ratooning. The results also indicate the period when soil erosion is likely to occur and the events which cause significant soil erosion. Moreover, we analyzed sediment discharge from virtual fields with different topographical conditions for 4 soils in Okinawa. The results showed that the greater sediment discharge was resulted in the longer and higher slope condition. Futhermore, the impact of different topographys to the sediment discharge amount differed depending on the soil types.

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  • Haichao LI, Hiroshi ISHIDAIRA, Kazuyoshi SOUMA, Jun MAGOME
    2020 Volume 76 Issue 5 Pages I_335-I_342
    Published: 2020
    Released: January 18, 2021
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     To prevent flooding in urban areas, the Chinese government launched the “sponge city” program, which is similar to the low impact development (LIDs) approach. However, the flood control capacity and cost efficiency of sponge cities in China have not been well studied, especially for city-scale urban area. Cost efficiency is an important consideration for local governments implementing sponge cities.

     The objective of this study is to quantify the utility of sponge city construction for urban flood control, based on a rainfall-runoff simulation using the Storm Water Management Model (SWMM). The cost efficiency of LIDs used in sponge city construction is also evaluated. Mianyang City, located in the southwestern part of China, was the study area. The results showed that the four types of LIDs (green roofs [GRs], permeable pavement [PP], rain gardens [RGs] and rain barrels [RBs]) effectively reduced the peak flow (23.0-30.4%) and total flood volume (24.9-29.2%) for nine flood events in 2015 and 2016. Different intensities (return periods) of precipitation have been analyzed to assess the flood reduction achieved through the installation of LIDs. For return periods of 2, 5, 10, 20, 50, and 100 years, the peak flow and flood volume reduction rates were 11.7-28.5% and 14.8-29.9%, respectively; these rates were lower in cases of more severe precipitation. The cost efficiency analysis showed that RGs are more cost efficient than other LIDs.

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  • Tosimasa TAKEDA, Yoshihiro ASAOKA, Tomoaki SATO, Seiji HAYASHI
    2020 Volume 76 Issue 5 Pages I_343-I_351
    Published: 2020
    Released: January 18, 2021
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     We investigated the mitigation effect of ”Paddy field dam” on inundation damage due to Typhoon Hagibis, 2019 in the Sasadaira River catchment where “Paddy field dam project” is implemented by Sukagawa city office. The inundation area was estimated from the measured river water level and the digital elevation map. The water storage of paddy field was calculated from the database of paddy shape delineated with areal photogrammetry with UAV.

     The results illustrated that the estimated water storage in the paddy fields in the upstream area decreased the inundation area by 50% and the inundation volume by 25% at the maximum flooded condition. It implies that paddy fields have a supplementary effect to mitigate inundation damage by working as a stormwater storage facility in the small river catchment even under heavy rain which exceeds design rainfall.

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  • Masafumi FUJITA, Thanh Hai BUI, Zeng LI, Jiahao DENG, Fengyu WANG, Yuj ...
    2020 Volume 76 Issue 5 Pages I_353-I_359
    Published: 2020
    Released: January 18, 2021
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     In low-lying Pacific atoll nations, the fundamental processes of formation and maintenance of coral reef islands are being destroyed due to anthropogenic factors such as domestic wastewater discharge as well as global ones. The aim of the present study was to develop wastewater treatment technology with power generation in sewer pipeline. The sewer-typed microbial fuel cell (MFC) had two stractual features: i) an anode was placed along with inside of the pipeline; ii) a cathode was able to receive H+ provided from HCl to avoid rate-determining cathodic reactions. A lab-scale sewer-typed MFC demonstrated an organic matter removal rate of 8.0 mg-C L−1 d−1 and a maximum power density of 94 mW m−2. However, the total internal resistance was 1.7 kΩ and the major contributors were identified as wastewater and anode. Thus, the improvement of these internal resistances will be key to enhance power generation in the sewer-typed MFC. A rough estimation showed that organic matter of ~25 % in domestic wastewater can be removed with a power generation of 4.7 kWh d−1, when this MFC technique is applied to sewer pipe with ~14 km distributed in the urban area of Majuro atoll, the Marshall Islands.

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  • Seiki KAWAGOE, Seiji HAYASHI, So KAZAMA
    2020 Volume 76 Issue 5 Pages I_361-I_370
    Published: 2020
    Released: January 18, 2021
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     In this study, we developed an Eco-DRR (Ecosystem based Disaster Risk Reduction) map for Mishima Town, Fukushima Prefecture, which is combine with forest industry and slope disaster reduction. As the information obtained from the map, we inducted suitable areas as produce paulownia tomentosa steudel. We expect the planting of paulownia tomentosa steudel to produce high quality timber and to control of slidding in slope failure. Suitable areas were determined from climate conditions, topographical conditions, and the characteristics and resistance of the paulownia tomentosa steudel.

     As a result, we found the existence of 8 suitable areas located on the upper slope zone of Mishima town. In addition, the points to be considered for planting forest were summarized compare suitable areas to the current vegetation situation. Through this research, Case example data has been prepared to build a social system to climate change adaptation.

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  • Junya TANIGUCHI, Kazuya WATANABE, Noritoshi SAITO
    2020 Volume 76 Issue 5 Pages I_371-I_376
    Published: 2020
    Released: January 18, 2021
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     Flowing into river of many driftwoods when it was raining heavily was placed at significant factor on enormous rain disaster mainly because driftwoods were deposited at a bridge and cause overflow then living area was damaged. So a lot of studies on relieveing damage caused by driftwood were carried out. However, study on process of exfoliation of driftwood was not conducted yet. Therefore, in this study, the hydraulic model experiments were carried out using flat rortating channel in order to investigate barking process. Firstly, it was confirmed that flow velocities at a real scale could be brought back in the channel in case the sediments were put into the channel. Next, driftwoods were flowed in state of only water or using sediments in water. Hereupon, driftwoods were not peeled off in fresh water and were peeled off in using sediment.

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  • Noritoshi SAITO, Kazuya WATANABE, Keita TAKAHASHI, Kana AKINAGA
    2020 Volume 76 Issue 5 Pages I_377-I_382
    Published: 2020
    Released: January 18, 2021
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     Ensuring a power source is one of the important issues for realizing an IoT society in which all things are connected to the Internet. Therefore, energy harvesting, which is an alternative power supply technology, is drawing attention. The authors are developing a micro hydroelectric generator using an inverted pendulum. In this study, we conducted hydraulic experiments on the effect of changes in flow velocity on pendulum motion and power generation. As a result, it was clarified that the power generator has a pendulum motion in the direction orthogonal to the water flow and generates power at a flow velocity of 0.32 m/s or more.

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  • Shintaro FUJIZUKA, Akira KAWAMURA, Hideo AMAGUCHI, Tadakatsu TAKASAKI
    2020 Volume 76 Issue 5 Pages I_383-I_391
    Published: 2020
    Released: January 18, 2021
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     Due to climate change associated with global warming, short-term heavy rainfall is increasing, and there are great expectations for the application of deep learning models to flood forecasting, which are being applied to various fields. Therefore, in this paper, it was decided to confirm how accurately the runoff model could be emulated by the deep learning model when the observation data contained observation noise. Virtual rainfall was used as input data, and virtual runoff height including observation noise with clear characteristics was used as teacher data. As the learning data, we evaluated the emulation performance of the runoff model by the deep learning model when the number of learning floods and the number of nodes in the hidden layer were changed. When the number of learning floods is small, we learned to match the noise component. Moreover, it was found that increasing the number of learning floods is effective to grasp the characteristics of the hydrograph, which is the true value without observation noise.

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  • Shigenori TAMASIRO, Yoshikazu MIYAMOTO
    2020 Volume 76 Issue 5 Pages I_393-I_399
    Published: 2020
    Released: January 18, 2021
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     In order to design of the local environmental certification system for coexisting sustainable industries with the coral reef ecosystem in Yaeyama district, various farming measures for reducing red soil runoff were evaluated on their sustainability and soil conservation. As a result, the ratooning was a recommended farming style for sugarcane that is sufficient as soil conservation and high sustainable farming. It is desirable to take at least one farming measure for the spring planting of sugarcane, and conducting the deep tillage or combine two or more farming measures are needed in the summer planting of sugarcane. In addition, it was also found that combining two or more measures are better for the cultivation of pineapple, vegetable and cut flowers.

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  • Kohji UNO, Runa KURODA
    2020 Volume 76 Issue 5 Pages I_401-I_407
    Published: 2020
    Released: January 18, 2021
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     In Japan, 34 national parks are designated for the conservation of outstanding natural scenic sites. More than 300 million people use the area annually. It is also an important space as an object of ecotourism and a visit from overseas. Under these circumstances, in order to ensure the sustainable use of national parks, the security of residents and users, disaster prevention with environmental protection in mind are indispensable. In this study, we carried out GIS spatial information analisis and a questionnaire survey of national parks nationwide, the risks of natural disasters and specific ecosystem service functions in national parks were clarified.

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  • Linghao MENG, Daisuke KOMORI
    2020 Volume 76 Issue 5 Pages I_409-I_414
    Published: 2020
    Released: January 18, 2021
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     Human activities have become one of the most crucial factors of the natural water cycle. This research is to assess the impact of human activities, especially land use and vegetation changes on the natural hydrological factors in the Loess Plateau, a region suffered the most severe soil erosion over the world. Since 1999, the government starts the water conservation project, forest and grass land increased significantly to replace most of the field land to more than 35%. Three stations at Loss Plateau are used to analyze water cycle parameter changes simulated by the land surface model H08 under the same climate and different land use scenarios. Four parameters of the model were optimized and validated by the observation discharge data from 1980 to 2014 at the three stations. The results showed good accuracy and validity of H08 applied in the region and simulations were conducted under optimized parameters. Results show that the returning farmland to forest and grass project can greatly both decrease and delay the flood peak, because by replacing farmland with forest the ability to contain water and sediment of soil dramatically increased.

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  • Thi Le Ha VO, Yoko SHIMADA, Minoru YONEDA
    2020 Volume 76 Issue 5 Pages I_415-I_431
    Published: 2020
    Released: January 18, 2021
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     The World Health Organization (WHO) has estimated that approximately 4 million premature deaths in 2016 were attributable to household air pollution in low to middle income countries. Vietnam is experiencing serious particulate matter (PM) pollution in ambient air and indoor environments, resulting in significant adverse health impacts. This article reviews and studies sources of PM in the indoor environment, personal exposure to PM during commuting (outdoor activities) and cooking (indoor activities), and the impacts of PM exposure on public health regarding disease and deaths. This article also studies current indoor pollution status and its mitigation in Vietnam. The results show that indoor PM concentrations exceed acceptable WHO recommended values in some cases. The indoor PM comes from indoor human activities, and outdoor particles transported through filtration airflow. Traffic activities have a great influence on indoor PM concentration and personal concentration. The types of transportation modes, fuels, and cooking methods make significant impacts on personal exposure, resulting in increased respiratory diseases and death in Vietnam. Despite the deterioration of indoor air quality, the concern from society still is ignored. Although there are mitigation efforts focusing on controlling indoor and outdoor particle pollutants, they remain insufficient in Vietnam. There is a lack of technical regulations and standards on indoor air quality, and there are minimal environmental protections, particularly for indoor air quality.

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  • Yusuke OHATA, Tomoko HASEGAWA, Yuki OCHI, Kiyoshi TAKAHASHI
    2020 Volume 76 Issue 5 Pages I_433-I_439
    Published: 2020
    Released: January 18, 2021
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     In this study, we clarified the health damage caused by climate change mitigation throughout undernourishment using multiple global agriculture economic models. As a result, the ambitious climate policy, if it is not properly implemented, would negatively affect human health. In the scenario equivalent to the 2 °C target agreed in the Paris Agreement, in 2050 DALY attributable to childhood underweight is expected to increase by 1.7 million years (0.16 to 2.75 million years), and the economic value of life lost is expected to increase by $4.4 to 200 billion (equivalent to 0.032-1.5% of global GDP in 2050), compared to the scenario without climate change and without climate change measures. This result suggests necessity of implementing complementary measures such as food support to the poor along with climate change mitigation.

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  • Farah Elida SELAMAT, Arisa INAMURA, Junta TAGUSARI, Toshihito MATSUI
    2020 Volume 76 Issue 5 Pages I_441-I_449
    Published: 2020
    Released: January 18, 2021
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     Road traffic noise is linked to a myriad of adverse health effects including environmental sleep disorder, hypertension, ischaemic heart disease, stroke, and diabetes. The health impacts are a growing concern globally. To reduce the health effects associated with road traffic noise, a shift from internal combustion engine vehicles (ICEVs) to electric vehicles (EVs) may be a transformative approach. In this paper, we focused on the health effects due to road traffic noise, and aimed to explore the potential of health risks reduction by transitioning to EVs in urban areas. Firstly, we calculated sound level in two areas with two different traffic flow situations: current traffic flows with ICEVs and the prospective ones with EVs. Next, we estimated the population affected with ischaemic heart disease and high sleep disturbance according to the exposure-response relationships established by the World Health Organization Regional Office for Europe and the national health statistics and surveys in Japan to elucidate the contribution of the transition to EVs. While the estimated reduction in sound level was less than 4 dB (even if all vehicles were changed to the EV), the affected population were reduced by approximately several tens of percent, hence, the total health risks due to road traffic noise would significantly reduce by the shift to EVs. A rapid transition to EVs is desirable to mitigate health risks due to road traffic noise as well as global warming.

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