International Journal of Environmental and Rural Development
Online ISSN : 2433-3700
Print ISSN : 2185-159X
ISSN-L : 2185-159X
10 巻, 2 号
選択された号の論文の27件中1~27を表示しています
  • JUN FUJIHIRA, BUNTHEA LY, THOME XAISONGKHAM, VEASNA PROM, ERIKA INOUE
    2019 年 10 巻 2 号 p. 1-7
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Flood is the most severe disaster in Cambodia because the country locates in the flood plain region. To tackle this national challenge, the Cambodian government has been developing policies and programs on disaster risk reduction. For supporting disaster-affected populations, various organizations provide humanitarian assistance before and after the disaster. However, due to country’s vulnerabilities, a number of Cambodians still suffer from floods, such as food insecurity and health problems. To decrease its vulnerabilities, community should build community resilience through build back better based on their past experiences, while receiving humanitarian assistance to enhance their capitals. As women are among the most vulnerable victims in post-flood situation, the study tried to understand existing major community capitals as well as gaps between humanitarian assistance and needs of vulnerable women. Totally 53 people consist from 33 female villagers and 20 key informants mixture of male and female were selected as respondents for Focal Group Discussions (FGDs) and Key Informants Interviews (KIIs) through purposive and snowball sampling approaches based on their status and experiences. The study concluded that humanitarian actors better to focus more on activities to enhance insufficient physical, natural, and financial capitals of the village for decreasing existing vulnerabilities including poverty, weak governance, and insufficient local structure for disaster risk reduction by applying Build Back Better approach, which build resilience of vulnerable areas based on past experiences and impacts.

  • EIJI MATSUO
    2019 年 10 巻 2 号 p. 8-13
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    When large structures are built on the soft ground such as paddy field, the demand for lightweight concrete will be high. However, issues related to quality control of lightweight aggregates, decline in the tensile strength of lightweight concrete, the economic problems, and so on, have been inhibiting the promotion of its development. There are some conventional methods of construction to cast the large size of expanded polystyrene (EPS) blocks near the surface of soft ground. But there is concern that the EPS block will float up by liquefaction in case of earthquake. In this study, the strength properties of lightweight concrete which uses EPS waste as fine aggregate have been investigated. The above-mentioned concern could be wiped out by mixing EPS as aggregate in concrete aggregate. This EPS aggregate is manufactured product, but there is extremely little number of the factories. The volume of this aggregate was reduced by being irradiated the extreme infrared radiation to utilize the stockyards effectively. This aggregate is ecological because its origin is the industrial waste of EPS. That the absorption of water is zero is one of the merits as the aggregate for concrete. The author has obtained experimentally the mix proportions for the concrete that have the compressive strength enough to be used as structural material. As the results, the treatment of EPS using extreme infrared radiation was found to be effective in improving the strength of EPS concrete.

  • HTAY HTAY OO, KHIN MAR OO, SWE SWE MAR, NAING NAING MOE
    2019 年 10 巻 2 号 p. 14-19
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    In Myanmar, pulses are a very important crop with great potential for export. Black gram (Vigna mungo L.) is one of the predominant pulse species grown, with planting after the harvest of monsoon rice in the winter season. Understanding the spatial variability of soil chemical properties is critical for improving the productivity of pulses and ensuring sustainable farming practices. However, a systematic assessment on the spatial variability of pulses yield has not been conducted. Therefore, this study was carried out to examine the variability of black gram yields in relation to soil chemical properties, at Kyee Inn Village, Pyinmana Township, central Myanmar from May 2017 to March 2018. Eighty composited soil samples were collected across the study area and analyzed for common soil chemical properties. Sixty seven farmers were surveyed as sample respondents to determine yields and management practices. Interpolation allowing overlay mapping of variations in black gram yields on soil chemical properties was accomplished using ArcGIS software. It was observed that these soil chemical properties and black gram yield varied considerably throughout the study area. Slight variability was observed in total nitrogen content. The pH value of the soils was moderately acidic to moderately alkaline with pH values of 5.48 to 7.58. The fields were characterized by low levels of soil organic matter and total phosphorus. The variation in black gram yields, ranging from 0.16 to 1.97 ton per hectare, is probably a result of the high variation of total soil nitrogen and phosphorus content. The results suggest that to improve soil fertility and sustain and improve black gram yields, it is very important to apply organic matter, nitrogen and phosphorus in parts of the study area.

  • NAING NAING MOE, SWE SWE MAR, AUNG KYAW MYINT, KYI TOE, KYAW NGWE
    2019 年 10 巻 2 号 p. 20-26
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Sustainable crop production requires detailed knowledge of the spatial variability of soil properties, such as soil nutrients. The primary purpose of this study was to assess the status of soil fertility by evaluating selected soil chemical properties, at Kyee Inn Village Tract, Pyinmana Township, Middle Myanmar using Geographic Information Systems (GIS). In this study soil samples were collected for the 80 grid references examined. Variables measured were soil pH, electrical conductivity (EC), cation exchange capacity (CEC), soil organic matter, and the total content of nitrogen and phosphorus. Grid size is 300 m × 300 m, covering an area of about 480 hectares, and samples were taken at a depth of 0-15cm using a Global Positioning System (GPS) to determine the coordinates of the sampling points. Soil fertility maps were generated using Inverse Distance Weighting (IDW) interpolation in ArcGIS software 10.5. Interviews were conducted with farmers to match results to soil management practices. The statistical analysis demonstrated a high variability of total nitrogen content with a coefficient of variation of 66.84%, while the soil pH and phosphorus levels showed the minimum variability in comparison to other soil properties. The pH values ranged from 5.48 to 7.58, while for phosphorus, minimum to maximum levels are 0.017% to 0.024%, respectively. Values for EC can be considered normal, with a mean value of 0.095 dS m-1 obtained. The CEC values ranged from 2.13 to 11.05 meq100 g-1soil. The low level of organic matter (0.2% to 1.7%) indicated a need to increase the organic matter content to ensure sustainable crop production. This study provides farmers with an effective management and decision-making model that encourages sustainable crop production.

  • PRAJYA NGAMJAN, THODSAPOL CHATURABUL
    2019 年 10 巻 2 号 p. 27-33
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Recognised as a Wetland of International Importance, the Nong Han Wetland (NHW), in Sakon Nakhon, Thailand, was selected as a study site for a risk assessment, which is an integral part of wetland management planning. The study demonstrated the process and presented the results of a risk assessment adopted in the NHW. The research postulates a simple risk assessment framework, where stakeholder participation is the key element. Following Ramsar’s guideline, tailored to suit the objectives of the study, the risk assessment framework involved (1) identifying problems and risks; (2) quantifying risks; and (3) proposing prevention and mitigation measures. Data were collected via focus group and questionnaire. The total number of participants was 217 stakeholders from 49 villages in the NHW. Eleven issues were identified, namely: (1) an increase in aquatic plant growth; (2) sedimentation; (3) degradation of water quality; (4) reduction and extinction of indigenous fish species; (5) non-existence of water laws; (6) land-rights; (7) conflicts of joint natural resource utilization; (8) sufficiency of data and information; (9) flooding; (10) draught; and (11) climate change. Risks were evaluated and ranked in terms of risk perception, and participants from different locations perceived degrees of risk rather differently. Nonetheless, when all the participants were analysed integratedly, the highest common risks shared were an increase in aquatic plant growth, sedimentation, degradation of water quality, and reduction and extinction of indigenous fish species. In addition, a set of risk prevention and mitigation measures was also drawn from the participatory risk assessment process. The results could be employed as a guideline for future plans and interventions of the wetland management following the bottom-up approach adhered to the Integrated Water Resources Management (IWRM) principles. The process not only drew conclusions and recommendations regarding risk management, but also created risk awareness and enhanced the degree of stakeholder engagement.

  • FARIDAH SITI, EIJI YAMAJI
    2019 年 10 巻 2 号 p. 34-39
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Ecotourism has been used to be an alternative for tourism activity while maintaining its natural sustainability. The spread of ecotourism in North Bandung that increased by number not only boosted the development of village area but also hoped to be able to improve the welfare of people living near tourist sites. This study looks at the tourism site's development and specializes in discussions on two tourist sites, Orchid Forest Cikole and Taman Bunga Begonia “Glory.” Literatures findings suggest awareness about environmental quality, education, and involvement of the local community, becoming a possible substance to be a benchmark of measurement of ecotourism concept. By using that measurement, this study seeks named sites ecotourism management and conditions by conducting in depth interviews with the tourism site owner and site marketing team leader. The result shows that even though some efforts are still in the planning stage, Orchid Forest Cikole has implemented quite several efforts to carry out the value of the ecotourism concept. Meanwhile, Taman Bunga Begonia “Glory” tourist sites, even though the land owned is relatively small and its starting from a hobby, this site applies a lot of the value of ecotourism concept.

  • PAKAYKAEW BOOTTARAJA, NAPAPORN PHUANGPORNPITAK
    2019 年 10 巻 2 号 p. 40-45
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    The power demand of electricity growing very fast with high concern of climate change and environmental constrains. According to the Thailand Power Development Plan 2015 (PDP 2015) starting from 2015 to 2036, the national target of 30% of renewable energy to total energy consumption by 2036 is to be achieved. Solar photovoltaic (PV) is an important option makes the PDP 2015 meets the target. This paper aims to present the performance analysis of the solar PV rooftop system installed at Sakon Nakhon Rajabhat University. The system consisted of 1,016 polycrystalline silicon PV modules coupled to 13 units of 25 kW grid tied inverter. This system will be installed at the rooftop of the three buildings namely, the Central Building (CB), the Engineering Technology Building (ETB) and the Multipurpose Building (MB). The PV rooftop system is designed using PVsyst program. The PV modules faced tilts and azimuths with 5°/31°, 10°/31° and 5°/16°, respectively. The simulation results indicated that solar PV rooftop system can produce 452.92 MWh/year. The solar PV rooftop system could produce electricity generating from 06.00 - 18.00. The performance ratio of the system is 0.74. The Central Building has maximum power electricity generating as 44.44%. The Engineering Technology Building has high performance ratio because of its tilts and azimuths of solar panels that affect the irradiation. The solar PV rooftop can reduce the peak demand in time 06.00-18.00 of 13.24% and the reduction of greenhouse gas emissions is 263.65 tco2/year.

  • PIYANUCH JAIKAEW, KONGRAT NOKKAEW
    2019 年 10 巻 2 号 p. 46-53
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    The root of vetiver grass has been proven to be effective to decrease erosion and increase slope stability for soil slope. The important role of vetiver grass roots in preventing water erosion and mass movement has been well recognized. However, quantitative researches that present the contribution of vetiver grass to erosion control and slope stability are limited, especially in the field study. This article presents the use of vetiver grass to slope erosion control and the role of vetiver root strength on slope stabilization for loose sandy soil slope which is located at north eastern part of Thailand. The erosion was measured in the field and then compared with the prediction from the Universal Soil Loss Equation (USLE) proposed by the USDA Agricultural Research Service. The soil layer and properties were investigated by borehole drilling and Kunzelstab penetration test, which shown the slope was built with loose sandy soil. The root tensile strength of vetivers was tested in the laboratory by using direct tension test. As the diameter of root increase, the shear strength of roots decreases as a function of exponential. The slope stability of slope stabilized with vetiver and without vetiver was analyzed using Infinite slope method. Slope with vetiver has significantly higher factor of safety when compared to slope in bare soil.

  • SEREIROTH BUNTHAN, YAMADA RYUICHI
    2019 年 10 巻 2 号 p. 54-60
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Sustainable agriculture is an integrated farming system of plant and animal production practices with site-specific applications that can maintain over the long term. It is both environmentally sustainable and also can generate several impacts on rural society. Unfortunately, the development of sustainable farming in Cambodia is still limited, and in its early stages. Despite sustainably farming has the potential for targeting niche markets and ensure higher incomes, it is reported that the number of farmers choose to do or revert to produce conventional rice farming instead. The application of chemicals in conventional agriculture can generate high productivity; however, the intensive use of the chemical has led to the destruction of soil and water resources. By observing these matters, this study aims to examine the differences in characteristics and profitability between 3 farming systems: conventional, partially organic, and organic rice farming, and to identify impacts from sustainable farming to rice farmers. The present study is based on the survey conducted in Prey Kabbas District, Takeo province, in 2018. In this study, a random sampling method was applied, and 75 rice farmers were interviewed. Among the samples, 30 farmers practiced conventional rice farming, and others 45 farmers practiced sustainable rice farming (25 adopted partially organic, and 20 farmers adopted organic rice farming). The findings showed that despite the production costs of organic rice farming is higher, organic farmers still ensure higher yield and generate better profit. Both of sustainable rice farming systems also found to benefit farmers with both social and human impacts. Nevertheless, there are some constraints inhered these rice farming in this study area, such as labor shortage, lack of organic materials, and market instability. There are needs for farmers, supported institutes, consumers to work together to promote organic rice farming in the study area.

  • THIDAR KHAING, SUU SUU WIN, NYO NYO WIN
    2019 年 10 巻 2 号 p. 61-66
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Compost is a decomposed organic material that can be used to help grow plants and keep soil healthy. The main objectives of this research are to prepare compost from agricultural wastes and study the physical and chemical properties of agricultural wastes and prepared compost. These agricultural wastes are cow dung, rice husk, saw dust, sesame husk and chaff. The physical and chemical properties of agricultural wastes and compost were characterized by pH, moisture, organic matter, calcium, magnesium, sulphur, nitrogen, phosphorus, and potassium. The EM (effective microorganism) solution was prepared by using organic kitchen wastes except onion and garlic peels for mixing in prepared compost. The microscopic morphology of microorganism was also studies for EM solution. The results showed that the prepared compost has pH value 7.29, moisture (20.39%), organic matter (22.89%), calcium (1.96%), magnesium (0.61%), sulphur (0.07%), nitrogen (1.25%), phosphorus (1.62%), potassium (1.56%), iron (1.30%), manganese (0.02%), copper (0.03%), zinc (0.01%) and chloride (1.07%). The yield percent of prepared compost was found to (58.45%) based upon the amount of agricultural wastes. The physical and chemical properties of agricultural wastes and prepared compost were used in soil management in a good way to improve and maintain soil quality, soil fertility, and conserve the environment.

  • XAYSATITH SOULIYAVONGSA, VIDHAYA TRELO-GES, SUPAT ISARANGKOOL NA AYUTT ...
    2019 年 10 巻 2 号 p. 67-72
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Following extensive land conversion from other crops to rubber plantations, Southeast Asia has become the main natural rubber producer in the world. Within Southeast Asia, Thailand is a leader of rubber production. This research addresses the question of the long-term effect of land conversion to rubber tree plantations on selected soil properties. The study reported here aimed to evaluate change in soil properties after 5 and 23 years of rubber tree plantation (5 RB, 23 RB) compared to soil properties under annual cash crops such as sugarcane (SG), in Kranuan district, Khon Kaen province, Thailand. Randomized sampling was conducted at soil depth increments from 0-10 to 150-160 cm. Topsoil organic carbon, total N and total K were higher in 23 RB than in the 5 RB and in the SG system. Available phosphorus in 23 RB was also higher than in soil under the 5 RB system, but not significantly different from that in the SG system. Soil pH was identical throughout the soil profile in the three observed cropping systems. We found evidence of soil compaction under the SG system at the 30-40 cm depth. Finally, topsoil in 23 RB had higher moisture content than that under the 5 RB and SG systems. Overall, this study indicated that, relative to cash crops such as sugar cane, conversion to rubber tree plantation in Northeast Thailand did not lead to land degradation and even improved some of the soil property indicators.

  • KEOVORLEAK VICHET, TOMOHIRO UCHIYAMA
    2019 年 10 巻 2 号 p. 73-79
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    The strong fluctuation of price makes investment decision difficult, especially smallholder rubber plantation that depend solely on rubber production to support their livelihood. An investment analysis of the rubber production was needed to complete the study, so a discounted cash flow (DCF) was introduced to account for this study. The findings of the study illustrate that the investment of rubber seemingly economically feasible. However, the result from the Discounted Cash Flow Analysis showed that the time to recover the initial investment on the rubber plantation is getting longer at the current price of rubber. The payback period will be 11.9 years for small size producers. For medium size plantations, the payback period was estimated to be 12.2, 10.5 and 9.8 years in MI, MII and MIII, respectively. The further findings also suggest that small size producers have less choice in term of output produce that they want to put out in the market.

  • RUBASHA MATIKU MUJAMA, YOICHI IZUMIDA
    2019 年 10 巻 2 号 p. 80-85
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    The main objective of this paper is to investigate why the sharp decline of sunflower seed production had occurred just after the starting of modern varieties promotion policy in Tanzania. Specifically, the study aims to (1) examine the changes in production of sunflower seed crop and that of its substitutable crop (sweet potato) for ten years, (2) determine the differences in profitability between sunflower production with modern varieties and production of related crops (sunflower seed with traditional varieties, and sweet potato), (3) examine the effect of relative price changes, (4) clarify other related factors such as famers’ characteristics in the adoption of new technologies, contract farming, and limited capacities of oil processing sectors. The field study was conducted in March and September 2018, selecting 270 farmers from three villages in Ikungi District. Based on the data obtained in the 2018 field study, profitability of the three types of cultivation was calculated. The result shows that sweet potato farmers received the highest economic return in terms of gross profit (545.7 TZS/ha) than sunflower farmers with modern seed varieties (397.0 TZS/ha). Sunflower farmers using traditional varieties received the lowest (273.7 TZS/ha). Furthermore, it was confirmed that changes in the farm gate prices over time had influenced profitability of three types of farming. At the starting time sunflower production with modern technologies had its advantage against sweet potato production. Farmers’ crop selection is mostly rational but institutional factors like contract farming and limited capacity of processing sector were the barrier for the change. Also, it was suggested that farmers need more education and training for more rational crop selection. Finally, from this case policy makers have to know that if the conditions are not well fulfilled the promotion of new technology may not have the desired result.

  • SARANYA SAETANG
    2019 年 10 巻 2 号 p. 86-90
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Nowadays, technology plays a significant role in business success. Technologies, including the Internet, web application, and social media can help to grow business by expanding distribution channels to reach customers, even in rural areas. In addition to technology, an online place to promote trade and the content of the products should be considered to help customers in buying decision processes. This research is conducted to understand how to create a proper content to promote online marketing. Consequently, good content can help to decrease the burden of web administrators who have to answer all frequently asked questions from customers. This paper begins with a literature review. Then, by using the focus group method, the customers’ factors were identified on buying experiences of indigo-dyed clothing, which is a popular product in the Northeastern region of Thailand. Moreover, the interview of an administrator of an indigo-dyed clothing’s web page as a purposive sample was summarized. By using content analysis, the results suggest some broad guidelines to present the content to promote products to gain the customers’ response and interest. The conclusion and future work will be mentioned to contribute to the academics and the sellers to sustain online businesses.

  • ANUCHA WITTAYAKORN-PURIPUNPINYOO
    2019 年 10 巻 2 号 p. 91-96
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    From past to present, the Thai economy has been heavily export-dependent, with exports accounting for more than two-thirds of its gross domestic product (GDP). Agricultural export product is one of the main export products but its tendency is declining. The research objectives were to study the impact of agricultural export products on the income and employment of the Thai economy. In this research, the data applied were collected as the yearly time series for a period of 27 years from 1990 to 2016 by the Bank of Thailand. The primary data were collected from the stakeholders of the agricultural product export policy of Thailand. Data analysis was based on descriptive statistics by the arithmetic mean and standard deviation. The Monte Carlo Simulation technique and time trend analysis was applied to the forecasting of agricultural product export value. In addition, the impact of agricultural export product on income and employment measured by the econometric model and the estimated parameters were calculated by the ordinary least square technique. The research results revealed that: agricultural export product value of Thailand from 1990 to 2016 was $10.270 billion with its yearly growth rate of 4.984 percent, in addition, the forecasting of agricultural product export value of Thailand has increased but its growth rate has declined. The impact of agricultural export products has a positive impact on income in the Thai economy; agricultural product export value of Thailand increased 1 percent which, in turn, led to the income increase by 0.0051 percent. In addition, the impact of agricultural export product value has a positive impact on employment in the Thai economy; agricultural export product value of Thailand increased 1 percent which, in turn, led to the employment increase by 0.079 percent. The Thai agricultural export product policy should be focused on finished or semi-finished agricultural products instead of raw materials by applying technology and innovation to make value-added agricultural product export.

  • KHIN MAR OO, HTAY HTAY OO, NYEIN NYEIN HTWE, HLA THAN
    2019 年 10 巻 2 号 p. 97-103
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Pulses play a vital role in contributing to food security and enhancing soil fertility. In Myanmar, pulses are the second most important crop after rice, and have a high potential for export. Mungbean (Vigna radiata L.) and black gram (Vigna mungo L.) are the major species of pulses that are widely grown throughout the country. The actual yield obtained at the farm level is still lower than the potential yield and pulse farmers are facing various problems and constraints. Considerable improvements of crop management practices are needed in pulse cultivation. Field experiments were conducted at Thongwa Township (lower Myanmar) and Pyinmana Township (middle Myanmar) from November 2017 to March 2018 to investigate the effect of crop management practices on yield and suitability of mungbean and black gram varieties grown in the study areas. Each experimental area was laid out in a split-plot design with four replications. Two crop management practices (Recommended practice and Farmers’ actual practice) were assigned to each main plot and four varieties of mungbean (Yezin-1, Yezin-9, Yezin-11 and Yezin-14) were planted at the Thongwa Township sites and black gram (Yezin-2, Yezin-5, Yezin-6 and Yezin-7) at the Pyinmana Township site, being assigned to sub plots. The results reveal that more yield and yield components were obtained in mungbean varieties grown following recommended practices than by farmers’ practices. However, the yield and yield components of black gram varieties are not significantly different between the two crop management practices. All mungbean varieties tested, except Yezin-11, are suitable for cultivation in Thongwa Township. Of the black gram varieties tested in Pyinmana Township, only Yezin-7 is unsuitable. Therefore, it is necessary to further investigate and possibly amend the recommended practices for these particular areas to improve the production of mungbean and black gram in these areas. In addition, demonstration plots that make use of these recommended practices should be organized to improve the awareness of farmers of the advantages of these techniques.

  • MOE TIN KHAING, HLA SAN WIN
    2019 年 10 巻 2 号 p. 104-109
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    This study revealed the determination of physicochemical parameters and characterization of mineral constituents of soils affected by the low-tech gold mining communities in the vicinity of Myitkyina town. The multi-increment soil samples with four replications were collected from two active mines (Location-1 and 2) and an abandoned mine (Location-3) during the first week of January 2018. Soil samples were analyzed for particle size distribution, pH, electrical conductivity, organic carbon, NH3-N, and available phosphorus. Soluble salts of soil water extract were also examined by titration method. Then characterizations of soil mineral constituents were investigated by advanced spectroscopic techniques such as Fourier Transform Infrared Spectroscopy (FT-IR), Energy Dispersive X-ray (EDX) and Scanning Electron Microscope (SEM). The result showed that soil sample from location-1 was loam sand and the other two soil samples were sand textural class. Soil pH, electrical conductivity, organic carbon, and available phosphorus were significantly different among the three gold mining areas whereas NH3-N content was not different by the gold mining. There was a high soluble salt accumulation in all locations. The highest soluble salt was Ca2+ followed by Mg2+. It was found that iron (Fe) contained as the highest relative amount in the soil which could exist with gold altogether and the second largest amount was given by titanium (Ti).

  • NAHO NOHARA, MINORU YOKOCHI, TADAO YAMAMOTO, TAKASHI INOUE
    2019 年 10 巻 2 号 p. 110-116
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    In lowland farmland, the maintenance cost of conventional inclined subsurface drainage systems is high because the drainage pipes must be laid at depth, or the tile deepens as the farm field enlarges. To reduce the maintenance cost, the Hokkaido Provincial Government of Japan has introduced a subsurface drainage system with a smaller inclination angle than the conventional method. However, the drainage effects of non-sloped subsurface drainage systems have been rarely reported, and insufficient evidence has prevented their widespread acceptance. The present study investigates how the slope of the drainage pipe influences the groundwater-level decrease in poorly drained fields. The survey was conducted in the upland field on peatland located in the Ishikari River Basin, Hokkaido. In 2015, two types of subsurface drainage systems were constructed in the same lot: a conventional subsurface drainage (sloped area) system, and a subsurface drainage system with low inclination (non-sloped area). After measuring the groundwater level at 12 points and the precipitation from 2016 to 2017, we found that: i) the groundwater level was higher in the non-sloped area than in the sloped area, ii) between 2016 and 2017, the groundwater level decreased in the sloped area and rose in the non-sloped area. The above results suggest that the efficiency of decreasing the groundwater level during 3 years after the construction was lower in non-sloped subsurface drainage than in sloped subsurface drainage, which is different from that observed in the previous study.

  • EMMANUEL OKIRIA, HIROMU OKAZAWA, YURI YAMAZAKI, YUKIMITSU KOBAYASHI, S ...
    2019 年 10 巻 2 号 p. 117-124
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    TOPMODEL, a topography-based, semi-distributed hydrological model was applied to the 84 km2 Atari catchment in Eastern Uganda. The study sought to identify the minimum number of rainfall events needed to optimally calibrate 5 unknown parameters for yearly hydrological simulation. Model input data was daily averaged precipitation, river discharge and evapotranspiration for the year 2015 with the output being simulated discharge. A rainfall event was defined as consecutive days of effective rainfall - effective rainfall being a daily rainfall ≥ 5.0 mm. Parameterization was done for Sequentially Accumulated Rainfall Events (SARE), beginning with 1 event and sequentially progressing until all 54 observed rainfall events in the year were used. All SARE had similar starting dates with the end dates being variable. The ‘true’ parameters were those derived from inputting all observed rainfall events while the other instances of the parameters from partial SARE were classified as ‘non-true’. Elimination criterion of ‘non-true’ parameters was set at an error of ±30%. Parameter values varied with the change in number of rainfall events, showing their dependence on rainfall characteristics. Downslope saturated transmissivity (Te) and maximum root zone storage deficit (SRmax) were the most and least variable from their means respectively. Also, exponential decay parameter (m) and delay time constant (td) needed the least and the greatest number of rainfall events to stabilise within the ±30% error bounds respectively. Therefore, the minimum number of rainfall events required to calibrate TOPMODEL and to optimise td in mid-sized equatorial catchments in Eastern Uganda are equivalent. Consequently, it required at least 49 rainfall events to calibrate TOPMODEL in 2015.

  • TAKANORI KANEKO, TOMONORI FUJIKAWA, MACHITO MIHARA
    2019 年 10 巻 2 号 p. 125-131
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Earthworms are important soil animals and perform vital functions in the soil that make better conditions for ecosystem, especially agriculture. Earthworms are involved in decomposing organic matters and mineralizing nutrients, controlling populations of pathogens, improving and maintaining soil structure and mixing organic matters in the soil. In this study, we discussed the effects of earthworm population and litter quantity on soil properties. Earthworm from the family of Megascolicidae was used in this study which is a native family of earthworm in Japan and accounts for more than 95% of earthworm family there. Experimental containers were set in the laboratory where earthworm population and litter quantity were controlled to observe its effect on soil properties. The results showed that, there was tendency of increasing survival percentage of earthworm. The Pearson correlation coefficient analysis showed that with increase in earthworm population and litter amount, there was increasing tendency in soil aggregates and available nitrogen content. The results for available phosphorus content and soil microbes did not show any relation with earthworm number and litter quantity.

  • VENICE B. IBAÑEZ
    2019 年 10 巻 2 号 p. 132-137
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Tourism has scaled into one of the biggest and fastest economic drivers in the world today. With the increasing number of new attractions, the imperative of assessing the competitiveness of tourism destinations is seen to be beneficial in improving its capability to create competitive advantages while ensuring adherence to sustainable development goals. Dubbed as “the best kept secret haven of Eastern Visayas”, Biliran Island Province as a tourism destination was assessed and analyzed using Porter’s Diamond Model of national competitiveness to propose useful strategies headed towards increasing its potentials and tourism competency. A total of 33 tourism stakeholder-respondents have undergone one-on-one interview survey in the said province to describe their perspectives on the importance and performance of various factors and conditions towards increasing its tourism competitiveness. Importance-Performance Analysis (IPA) revealed that the tourism competitiveness of the province is directed to its eminent natural resources, safe and secured environment, and provisions of basic facilities. However, performance improvement of other factors especially marketing and advertising must be addressed promptly. Various concerns and challenges that the province facing include lack of government support in terms of product development and promotion, high taxes and cost of other basic utilities, and environmental challenges as a result of climate change. To address these adversities of, ecotourism-related strategies were recommended in line with the positioning of the province as an “Agri-Garden and Premier Ecotourism destination in Eastern Visayas Region”. These must involve responsible marketing and advertising, human resource development and environmental-friendly infrastructures, and emphasis on intensifying safety and disaster risk reduction and preparedness management.

  • YURI YAMAZAKI, KIICHIRO HAYASHI, NOBUKO KAWAGUCHI, HIROMU OKAZAWA, FER ...
    2019 年 10 巻 2 号 p. 138-145
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Due to the increase in international energy demand and the focus on the realization of a decarbonized society, small-scale hydropower plant is attracting attention in Japan as an important supply of renewable energy. While Japan has a significant amount of precipitation and mountains, it is suitable to establish hydropower plants; however, hydropower energy currently represents only about 10% of the total energy mix. Generally, a small-scale hydropower facility has relatively little impact on the environment and is expected to play a role as a distributed power source. However, it has not been included in the survey of hydropower potential, and a study on its viability and the development of potential sites is limited. Here, we created an electricity generating capacity map for small-scale run-off-river hydropower plant of the Yahagi River system in Aichi, Japan. We calculated the river flow rate and potential electricity generating capacity at every 10 m on the river line of the Yahagi River system using the digital elevation model, published by the Geospatial Information Authority of Japan. We overlapped various kinds of social conditions and risks on the map of electricity generating capacity and proposed a suitable site where the development of potential small-scale run-off-river hydropower plant is high.

  • CHANMONY SOK, TOMOHIRO UCHIYAMA, NINA N. SHIMOGUCHI
    2019 年 10 巻 2 号 p. 146-151
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Through the Cambodian government program, adoption of organic rice farming started in 2003. Although some farmers re-converted back to conventional rice farming, there are still some farmers who have continued producing organic rice under contract farming and non contract farming. This study aims to (1) clarify the cultural practices of organic rice farming; (2) compare the productivity and profitability of organic rice under contract farming and non-contract farming, and (3) identify the perception of farmers towards organic rice farming and reasons why they have continued. This study interviewed 85 randomly selected farmers in a commune of Preah Vihear province and further divided them into three types: 32 contract farmers, 32 non-contract farmers, and 21 organic rice contract farmers who partly sold produce outside the contract. Results showed that although transplanting and direct-seeding were prevalent, direct-seeding was the most common practice due to limited labor and rice field location. With regards to productivity and profitability, organic rice contract farmers had more yield and earned more profit than non-contract farmers. Moreover, farmers practicing transplanting had higher yield than those of direct-seeding. However, availability of exchange labor seemed to be a critical factor for farmers to gain profit. The reasons for farmers to continue doing organic rice farming were higher income, better health and contribution to conserve the environment. The reasons for engaging in contract farming were receiving stable and high price and gaining new knowledge. This study hopes to initially contribute to the further development of organic rice farming in Preah Vihear province.

  • DALIN SUN, TOMOHIRO UCHIYAMA, NINA N. SHIMOGUCHI
    2019 年 10 巻 2 号 p. 152-157
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Labor scarcity is the most common problem for Cambodian farmers during harvesting season since they commonly harvest rice manually. To reduce harvesting loss, expenses and time, a well-designed combine harvester is gaining popularity. This study aims to evaluate the economic performance of using combine harvesters in rice cultivation. Specifically, this study aims to (1) clarify the reasons farmers adopted the use of combine harvesters, and (2) compare the profitability of rice farming between combine harvester owner-farmer and non-owner-farmer. This study was conducted in Banan district, Battambang province, where utilization of combine harvesters is prevalent. A total of 68 respondents who use combine harvesters were randomly selected and interviewed using a questionnaire and further categorized into 34 combine harvester owner-farmers and 34 non-owner-farmers. The study has four main findings. First, most farmers started using combine harvesters in 2010 due to labor shortage and high wagers. Combine harvester owner-farmers spent lesser total production cost compared to non-owner-farmers. Second, the total production cost of both farmer types varied mainly on the variable cost since the non-owner-farmers spent more on rice harvesting fee, while combine harvester owner-farmers spent only on the cost of diesel, depreciation, and driver. Third, combine harvester owner-farmers received the higher profitability compared with the other. Fourth, the three main reasons for adopting the use of combine harvester were labor shortage during peak harvesting season, convenient harvesting on time, and opportunity to provide custom service to other farmers.

  • KITICHOKE PROMMANEEWAT, SUPALAK SATHIRACHEEWIN
    2019 年 10 巻 2 号 p. 158-163
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    In this experiment, we studied the construction of incinerators using Hydrogen gas as fuel in small hospitals. The Hydrogen Gas Incinerating System in this study consists of 3 major parts, the Water Separation System, Furnace and Combustion System, and the DC Power Control System. The authors used water mixed with Sodium Bicarbonate (NaHCO3) solution to separate Hydrogen (H) from water by using 12 VDC and 15.50 A which resulted the 909.09 ml/min of gas flow rate to burn 100 grams of infected waste. The experiment showed that the waste was completely burnt into ash within 13.35 minutes and the average power consumption was 0.04 kW-hr. It was concluded that the gas flow rate should not be less than 800 ml/min because it can have a fire back phenomenon. The result also showed that the burning cost of waste incineration in this study equaled to 1.50 baht/kg which was much cheaper than the one of general infected waste in hospital which costs 5 baht/kg.

  • NYO NYO WIN, THIDAR KHAING, SUU SUU WIN
    2019 年 10 巻 2 号 p. 164-169
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    The present research studied how the addition of peanut shell to the soil effected on physicochemical properties of soil and plant growth. Waste peanut shells were used to enhance soil properties by composting for cultivation of plants as the organic fertilizer. In the composting step, 2:3 (v/v) of peanut shell and soil was mixed for two months and utilized for the cultivation of maize plants. Some parameters of soil, peanut shell and peanut shell-compost such as pH, moisture, nitrogen, phosphorus, potassium, organic carbon, total sulphur, calcium and magnesium were examined by using their respective standard methods to compare the properties of control and compost-soil. It is observed that the soil added with peanut shell-compost has a potential increasement of nitrogen, phosphorous, potassium, total sulphur, total calcium and total magnesium in plant growth media than control soil. The results obtained in plant growth media also pointed out that the growth rate and yield percent with composed soil were better than those of control soil. These research findings can contribute to the local people from agricultural field with the scientific information of waste peanut shell as low cost alternative fertilizer.

  • THODSAPOL CHATURABUL, THANAPORN SUPRIYASILP, KOBKIAT PONGPUT
    2019 年 10 巻 2 号 p. 170-175
    発行日: 2019年
    公開日: 2021/02/25
    ジャーナル フリー

    Mekong, a major trans-boundary river, is one of the main source of hydropower for many Southeast Asian countries. Sources of the hydropower come from many mega-dams along the river. However, constructing mega-dams for hydropower causes numbers of hydrological effect especially with the change of water flow and water level along the river. Nakhon Panom, a province located by the river bank in Thailand, has been severely affected by the hydropower dam operation. To solve these dilemmas effectively, a set of up-to-date data from all perspectives is need for the analysis, however, the data that reports on a transition of hydrological after dam construction are currently limited. This study aims to respond the needs of data by investigate the change of water flow and water level before and after the dam construction using various indicators under the principle of Indicators of Hydrological Alteration (IHA). Hydropower project timeline was created to analyze the daily discharge and water level from 1964 to 2013. Findings portrayed that the water flow had been significantly changing and may directly affects people along Mekong River in terms of their livelihoods, agriculture and tourism activities (e.g. Songkran Festival). The results of this study also can be used as a reference data for hydrological analysis in the future.

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