Journal of the Japanese Agricultural Systems Society
Online ISSN : 2189-0560
Print ISSN : 0913-7548
ISSN-L : 0913-7548
Volume 29 , Issue 2
Showing 1-7 articles out of 7 articles from the selected issue
Contributed Paper
  • Durina, Ryota NAGASAWA, Boonrak PATANAKANO
    2013 Volume 29 Issue 2 Pages 29-39
    Published: April 10, 2013
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    In Asia's emerging countries, urbanization occurs along with the fast population growth that follows the phenomenon of rapid economic development and centralization of industries and population into mega-cities. A typical example of this type of centralization can be seen in the Bangkok Metropolitan Region, Thailand. In this study, the latest high resolution satellite remote sensing images, as well as the existing GIS data, were integrated to generate temporal (1994, 2000, and 2009) land use/cover maps that could be used to understand the recent expansion process of urban areas and the spatial variations of rural agricultural landscapes in the suburbs. These maps showed that the proportion of urban/built-up area has been increasing, from 16.5 % in 1994, to 28.2 % in 2000, and 35.4 % in 2009. This rate of change was 171 % between 1994 and 2000, and 126 % between 2000 and 2009. In contrast, the agriculture/vegetation area continuously decreased from 71.4 % in 1994, to 56.1 % in 2000, and 43.3 % in 2009, for a rate of change of 79 % between 1994 and 2000, and 77 % between 2000 and 2009. Central Bangkok was completely built up by 2000, and the urbanized areas have largely spread to the 5 adjoining provinces, causing a sprawling phenomenon into the suburban rural landscapes. The landscape changes were mainly due to the conversion of agriculture areas into artificial built-up areas. Consequently, urban and rural land uses were extremely mixed in the suburbs, and different land uses became competitive. The landscape metrics analysis also showed that agriculture/vegetation area consisted of a number of small sized patches, indicating the fragmentation of landscapes. The most of recent urbanization has spread beyond the existing land use planning control and has invaded into the urban fringes closest to central Bangkok, even though where the landscapes were principally protected as agricultural and/or conservation zones. The fragmentation and shape complexity of the rural landscape therefore appear to have arisen due to the uncontrolled urbanization that has occurred more recently in the urban fringes. In order to avoid any further fragmentation of landscapes in these areas, it is highly recommended to incorporate landscape analysis into the urban planning process.
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  • - A case study based on the Haousa and Foulani people of Southern Niger -
    Yohei KOMURA, Ueru TANAKA, Yuko SASAKI, Hitoshi SINJO
    2013 Volume 29 Issue 2 Pages 41-50
    Published: April 10, 2013
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    In the West African Sahelian region, where people's livelihoods are based on farming and animal husbandry, irregular rain and drought are common occurrences. This study focus on the Haousa and the Foulani people living in villages found within this region. Through a deeper understanding of the livelihoods, this study aims to analyze and elucidate how people of each village recognize “crisis years” and how they cope with them. Attention is given to how the recognition and reaction to “crisis years” may be different depending on geographical location and ethnic composition of the villages. The study area includes two Haousa villages and one Foulani village located within the Tessaoua Commune in Tessaoua Prefecture of Maradi State in southern Niger. Structured interviews were conducted at 25 households per village. The interview questions mainly focused on recognition and reaction to “crisis years” among the Haousa and the Foulani people alongside basic information regarding the household. The study revealed how major “crisis years” are given a local name, and is remembered by its story being passed down through oral traditions. Recognition of “crisis years” varied between Haousa villages. The variation mainly depended on geographical location of the village and secondary occupations such as fishing and vegetable cultivation that served as a means to better cope with various “crisis”. Commonalities were found in how “crisis years” are recognized between the Haousa and Foulani people that are two different ethnicities. “Crisis years” for the Foulani people are years when there is a loss of livestock, and also, just as it is for the Haousa, depends on the amount of total crop yield. Comparison between the two ethnic groups revealed how livelihoods of the Foulani, based on livestock breeding and plant cultivation in their permanent home, are similar in form to that of the Haousa. With regards to coping activities to “crisis years”, differences were seen between “crisis years,” as well as geographic location and ethnic group. Additionally, coping activities were prioritized during a “crisis year”, depending largely on the degree of hardship experienced within each household.
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  • Fumio YAMAGUCHI, Masae SHIYOMI, Takashi TAKEUCHI, Akitoshi SHIRAIWA, T ...
    2013 Volume 29 Issue 2 Pages 51-57
    Published: April 10, 2013
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    On March 12, 2011, the Fukushima Daiichi Nuclear Power Plant of the Tokyo Electric Power Company caused a sequent hydrogen explosion. After the explosion, the atmospheric radiation doses at measuring points in Mito City, Ibaraki Prefecture, have rapidly increased, which have caused the concerns about the bad effects on residents' life by the atmospheric radiation doses. For our analysis, we prepared a model for forecasting the future fluctuations of the atmospheric radiation doses in Mito City. This model was built based on the exponentially decreased radiation doses, depending on their own decay rates; these radiation doses were resulted from the nuclear plant accident and rectified by natural decontamination, by wind and rain, of the radiation doses environmentally accumulated. We made a forecast of the atmospheric radiation doses between April, 2012 and March, 2014, by applying this model. This forecast shows that the radiation doses of Mito City would be reduced until March, 2013, two years after the accident, to the level a little higher (0.065 μSv/hr) than the natural radiation doses before the accident (0.056 μSv/hr), and that the radiation doses of Mito City in March, 2014, three years after the accident, would be reduced to the level of natural radiation doses. The forecast values of the yearly accumulated atmospheric radiation doses measured by hourly basis shows that the values would be reduced to the natural radiation level (1 mSv/yr), both one year and two years after the accident. As for the suddenly increased radiation doses frequently observed, we clarified by multiple regression analysis that these phenomena were caused by the combination of both “heavy precipitation” and “high wind velocity”.
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  • Hirotsugu KAMAHARA, Chikashi KUBO, Naohiro GOTO
    2013 Volume 29 Issue 2 Pages 59-66
    Published: April 10, 2013
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    Recent year, natural farming and organic farming has received attention owing to rising interest in the health benefits and concern environmental problem. These farming methods can be considered as low energy consumption by these farming, because they do not use chemical fertilizer and pesticide. On the other side, these farming methods also can be considered as high energy consumption by weeding and rice field management. Therefore, purpose of this study is to clarify life cycle energy consumption of the rice cultivation without chemical fertilizer and pesticide use by investigation of these farmers. This study investigated A and B farmer who are doing organic farming in Shinshiro, Aichi prefecture, and C farmer who is doing organic farming and D farmer who is doing natural farming in Shirakawa, Gifu prefecture. Land use area of these farmers is less than 0.5 ha, and located in hilled rural area. In addition, these farmer works by manual and drying rice under the sun. Especially, B and C farmer interact with consumer and student through these activities. This study compared the results with conventional rice cultivation of previous study using chemical fertilizer and pesticide having 15 ha of land area. The result showed that energy consumption per land use area of investigated farmer has wide range with 4.3~9.5 GJ/ha. In addition, energy consumption of investigated farmer is less than conventional rice cultivation, because they can work by manual and drying rice under the sun. These results indicated that interaction with consumers, traditional farming method like dry of rice under the sun and years of experience for rice cultivation without chemical fertilizer and pesticide use are contributing reduction of the energy consumption.
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Technical Paper
  • Mikinori TSUIKI, Yoshiko HINOSAWA, Ryo HATANAKA, Shunta KANNO, Takeki ...
    2013 Volume 29 Issue 2 Pages 67-73
    Published: April 10, 2013
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    Large releases of radionuclides from the Fukushima Daiichi Nuclear Power Plant have resulted in serious radioactive pollution of a wide region of Eastern Japan. Air dose rates throughout Iwate Prefecture were measured with hand-held dosimeter from June 1 to July 2, 2011. The maximum value by the travel survey method (0.24 µSv/h) was observed at Maesawa Ward, Oshu City in June 2, 2011. The maximum value by soil surface measurement (0.45 µSv/h) was observed at Maesawa Ward, Oshu City in June 5, 2011. Contour maps of air dose rates were made with collected data. “Hot spot” was seen at the boundary area of Ichinoseki City, Oshu City and Hiraizumi Town. These distribution patterns corresponded to the results of airborne monitoring results of radiation dose by MEXT. These results indicate that distribution patterns of air dose rate would be estimated by travel survey and soil surface measurement with reliable hand-held commercial dosimeter. Air dose rates derived from fallout radioactive cesium at 30 years after the accident were predicted to be 13.5% of initial dose rates.
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  • Naoki ISHITSUKA, Tsukasa MAKINO
    2013 Volume 29 Issue 2 Pages 75-80
    Published: April 10, 2013
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    In order to reduce expensive purchased feed and increase the use of self-support feed, because of the increasing import grain and feed prices, the production quantity of feed crops is increasing in various places. On the other hand, the officially statistics of silage corn planted area were published only prefectures unit after the 2007 fiscal year, and it became difficult to acquire objective information about planting areas for each city, town, and village. Therefor silage corn planted area grasp with the satellite is expected. Although the operation range was limited, in order to explore the possibility of detecting silage corn planting fields, simple analysis was tried using time-series ALOS/PALSAR data. Unsupervised classification was carried out using the calculated mean values of back scatter coefficients of the ALOS/PALSAR data for each agricultural parcel (i.e., on the basis of the change in the backscatter coefficients). As a result, the plantation areas were successfully detected. The map of the silage corn planting fields created from the ALOS/PALSAR data agreed well with the one created by the TMR center. Out of the 29 fields that were judged to be silage corn crops according to the satellite data, 27 were accurately identified (i.e., User's accuracy of 93.1%). On the other hand, the results regarding other crops were not as accurate. It is considered that ALOS/PALSAR is suitable for detecting fields where large-biomass agricultural products like silage corn are planted, because ALOS/PALSAR is an L-band SAR, which is operated at a wavelength longer than that of the microwave SAR currently used.
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Short Communication
  • Katsuo OKAMOTO
    2013 Volume 29 Issue 2 Pages 81-86
    Published: April 10, 2013
    Released: June 04, 2015
    JOURNALS FREE ACCESS
    Using multitemporal Landsat MSS (Multispectral Scanner System)/TM (Thematic Mapper)/ETM+ (Enhanced Thematic Mapper Plus) data, changes in the beach of Enshunada around the Tenryugawa estuary were evaluated. The modified normalized difference water index (MNDWI) and the normalized difference vegetation index (NDVI) were calculated for each image. Using those indices, each image was classified into three categories: water, soil and built-up, and vegetation. Comparing among classified images at the high or low tidal level, changes in the beach were evaluate. The result shows that the beaches around the Tenryugawa estuary retreated landward. On the other hand, the Nakatajima beach extended seaward. This shows that offshore breakwaters which have been constructed since 1961 are probably effective.
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