論文 - 岡澤 宏
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Mazibuko, Dickson Mgangathweni, Sarvesh Maskey, Kiseki Kurashina, Hiromu Okazawa, Hiroyuki Oshima, Taku Kato, and Hidehiko Kikuno
Crops 5 ( 2 ) 2025年03月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：MDPI
Globally, Hibiscus sabdariffa L. (Malvaceae), commonly known as roselle or hibiscus, is a multipurpose vegetable crop. In Malawi, where it is referred to as ‘Chidede’ (Chichewa), it is recognized as an underutilized traditional plant with significant potential. Traditional vegetable production in Malawi is being promoted to enhance nutritional food security and climate change mitigation. Recently, biochar has become increasingly used to improve agricultural productivity through climate-smart technologies. To date, the influence of rice husk biochar (RHB) on H. sabdariffa remains underexplored. This study aims to evaluate the effects of RHB on the vegetative growth, response to water stress, and post-stress recovery of H. sabdariffa using a greenhouse pot experiment. Our findings indicate that biochar-amended soil enhanced plant height, stem thickness, and total leaf area by 16.5%, 12.0%, and 12.9%, respectively. Water stress significantly reduced all assessed growth parameters (p < 0.05) except total leaf area and average leaf area per plant. Under water stress conditions, biochar-treated plants were significantly taller (p < 0.05) and had a higher specific leaf area (p < 0.05), demonstrating a positive effect. A post-stress recovery analysis revealed that H. sabdariffa fully recovered in height and biomass, while partial recovery was observed for root collar diameter and compensatory recovery for total leaf area and average leaf area. Biochar-treated plants exhibited superior post-stress recovery compared to those grown in unamended soil. Overall, plants grown with biochar were taller and had a larger root collar diameter, higher stem and leaf fresh biomass, and greater total leaf area. These findings underscore biochar’s potential as a sustainable soil amendment for enhancing growth and resilience in underutilized crops. Further studies should explore field experiments to access environmental heterogeneity and examine the diverse factors influencing biochar efficiency.
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Dickson Mgangathweni Mazibuko, Ruth Nyambura Maru, Hiroko Gono, Hiromu Okazawa
Transactions of the Royal Society of South Africa 1 - 18 2025年02月
担当区分：最終著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Taylor&Francis
To date, spices remain comparatively the least produced and utilised of all crops in Malawi irrespective of their nutraceutical importance. Onions (Allium sp.) and peppers (Capsicum sp.) are Malawi's main spices, and to a lesser extent ginger (Zingiber officinale) and garlic (Allium sativum); they are commonly used in cooking and as medicine. Recently, “new” spices, with high nutraceutical values documented in other countries, are emerging on Malawi's local markets. This points to an increasing pool of spice crops whose diversity and comparative utilisation dynamics remain poorly understood. This study aimed firstly to determine spice species diversity, secondly to determine the context of utilisation (culinary and medicinal) and finally to trace scientific validation of the bioactivity for spices ‘reported’ to be used in treating various ailments. The main intention was to expose the potential of spice crops in improving household and community diets and health. Data was collected from interviews with spice traders and customers/consumers. In this study 33 spice species belonging to 29 genera and 14 families were found in markets. Twenty species had a reported medicinal purpose, of which 80% had scientific validation from experiments on humans (55%) and animals (25%). Common ailments managed by spice usage in Malawi include diabetes, hypertension, obesity, and immunity boosting, all identified as emerging health concerns in the country. In Malawi, 80% of the population is reliant on plant-based medicines. Deliberate promotion of spice consumption and production is a pivotal pathway to diversifying plant-based medicine resources along with increasing agrobiodiversity and the associated dietary diversity. Coordination among health, nutrition, and agriculture experts and policymakers will be key in unlocking the potential that spice crops hold for Malawi.
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Ke Zhang, Lameck Fiwa, Madoka Kurata, Hiromu Okazawa, Kenford A.B. Luweya, Mohammad Shamim Hasan Mandal, Toru Sakai
Scientific African 26 ( e02431 ) 2024年10月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：ELSEVIER
With the development of unmanned aerial vehicle (UAV) in the recent decade, very high-
resolution aerial imagery has been used for precise land use/land cover classification (LULC).
However, special structures in rural areas of developing countries such as traditional thatched
houses have posed challenges for precise LULC classification due to their undistinctive appearance
and confusable characteristics in both reflectance and structure. LULC mapping is essential
particularly in rural areas which have high data scarcity and vulnerability to natural disasters.
With high-resolution observation has been achieved by UAVs, it is important to propose high-
precision LULC classification methods which can fully use the advantages of UAVs. To emphasize
the differences among the common LULC types in rural areas, this study proposed an original
index, the rural residence classification index (RCI). RCI was calculated as the product of the
above ground height and the square of the difference between the NDVI value and one. Then, a
comprehensive classification method was established by combining the RCI, the traditional
threshold method and a machine learning method. As a result of the comparison with the
traditional threshold method, object-based image analysis, and random forest methods, the
method by this study achieved the highest overall accuracy (overall accuracy =0.903, kappa =
0.875) and classification accuracy for detecting thatched houses (user’s accuracy =0.802, producer’s
accuracy =0.920). These findings showed the possibility on identifying the confusable
structures in rural areas using remote sensing data, which was found difficult by the previous
studies so far. The method by this study can promote the further utility of UAVs in LULC classification
in rural areas in developing countries, thereby providing precise and reliable material
for hydrological, hydraulic or ecosystem modelling, which eventually contributes to more accurate
natural hazard risk assessment, rural development, and natural resource management.DOI： https://doi.org/10.1016/j.sciaf.2024.e02431
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Maru, Ruth Nyambura, John Wesonga, Hiromu Okazawa, Agnes Kavoo, Johnstone O. Neondo, Dickson Mgangathweni Mazibuko, Sarvesh Maskey, and Francesco Orsini
Horticulturae 10 ( 5 ) 2024年04月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：MDPI
Microgreens are innovative vegetable products whose production and consumption are gaining popularity globally thanks to their recognized nutraceutical properties. To date, the effects of lighting conditions and growing substrate on the performances of Brassica carinata microgreens (indigenous to Africa) remain underexplored. The present study aimed at providing insights into the influence of different lighting treatments provided by LEDs, namely monochromatic blue (B), red (R), cool white (W) and a combination of three color diodes (B + R + W), and substrates (cocopeat, sand and cocopeat–sand mix (v/v) (1:1)) on the growth, yield and bioactive compounds of B. carinata microgreens. Seeds were germinated in dark chambers and cultivated in growth chambers equipped with LED lighting systems for 14 days under a fixed light intensity of 160 ± 2.5 µmol m−2 s−1 and photoperiod of 12 h d−1. The best performances were associated with the spectrum that combined B + R + W LEDs and with substrate resulting from the cocopeat–sand mix, including the highest yield (19.19 g plant−1), plant height (9.94 cm), leaf area (68.11 mm2) and canopy cover (55.9%). Enhanced carotenoid and flavonoid contents were obtained with B + R + W LEDs, while the B LED increased the total amount of chlorophyll (11,880 mg kg−1). For plants grown under B + R + W LEDs in cocopeat, high nitrate levels were observed. Our results demonstrate that substrate and light environment interact to influence the growth, yield and concentration of bioactive compounds of B. carinata microgreens.
DOI： https://doi.org/10.3390/horticulturae10050436
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Insights into the journey towards development of dietary guidelines: An exploration of synergy between fruit and vegetable research with food composition tables in Malawi "jointly worked" 査読あり 国際共著
Dickson Mgangathweni Mazibuko, Victoria Ndolo, Satoko Akiyama, Hiromu Okazawa
African Journal of Food Science 17 ( 2 ) 256 - 267 2023年12月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Academic Journals
Publication of the Malawi Food Composition Database (MFCDB) is a milestone towards improving the nutritional status and overall health of citizens. Following the establishment of this database, the next step involves formulating food-based dietary guidelines tailored for Malawi. However, both the database and the planned dietary guidelines are dependent on robust research on food composition. This analytical review utilizes fruit and vegetable research done in Malawi, to analyze synergies with the published food composition tables and limitations. Results point to inadequate fruit and vegetable nutrition research in Malawi. Less than 1% of published vegetable research has dealt with nutrient composition. Of this, only 15% has contributed to the food composition database, forcing 52 and 39% of entries (values) for fruits and vegetables, respectively to be borrowed. However, more research on fruit and vegetable species has been done than is captured in the database. There exists dissonance in analytical methods between research and database needs. This lack of methodology impacts overall data comparability and reliability. It is suggested that the Malawian Food Data System, provide standardized methods of analysis for various food composition parameters, priority list of species, and nutrient profiles of immediate national relevance. The planned dietary guidelines will require a multisectoral approach, and policy modifications to facilitate fit-for-purpose research in fruits and vegetables.
DOI： 10.5897/AJFS
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Quantification of Amu River Riverbank Erosion in Balkh Province of Afghanistan during 2004–2020 "jointly worked" 査読あり 国際共著 国際誌
Mahmoodzada, Abdul Basir, Divyesh Varade, Sawahiko Shimada, Hiromu Okazawa, Shafiqullah Aryan, Gulbuddin Gulab, Abd El-Zaher M. A. Mustafa, Humaira Rizwana, Yogesh K. Ahlawat, and Hosam O. Elansary
Land 12 ( 10 ) 1890 2023年10月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：MDPI
In this study, we propose quantifying the Amu River riverbank erosion with the modelled river discharge in Kaldar District, Balkh Province of Afghanistan from 2004 to 2020. We propose a framework synergizing multi-source information for modelling the erosion area based on three components: (1) river discharge, (2) river width, and (3) erosion area. The total river discharge for the watershed shared by Afghanistan and Tajikistan was modelled using hydrological parameters from the European Centre for Medium-Range Weather Forecasts (ECMWF) Reanalysis v5 (ERA5) data through multivariate linear regression with ground station data. The river width was determined manually using the Normalized Difference Water Index (NDWI) derived from Landsat data. The riverbank erosion area was derived from the digital shoreline analysis using the NDWI. The digital shoreline analysis showed that, between 2008 and 2020, the average riverbank erosion area in Kaldar District is about 5.4 km2 per year, and, overall, 86.3 km2 during 2004–2020 due to flood events. The significantly higher land loss events occurred at 10 km2 bank erosion during the years 2008–2009 and 2015–2016, and 19 km2 peak erosion occurred during 2011–2012. A linear relation between the erosion area with respect to the discharge intensity and the specific stream power was observed with an R2 of 0.84 and RMSE of 1.761 for both.
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Mazibuko Dickson Mgangathweni, Hiroko Gono, Sarvesh Maskey, Hiromu Okazawa, Lameck Fiwa, Hidehiko Kikuno, and Tetsu Sato
Sustainability 15 ( 6 ) 4747 - 4747 2023年03月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：MDPI
Agricultural productivity impacts the environment and natural resources in various ways. The severity of these impacts has triggered the emergence of natural resource management and the related, highly criticized science of agroecology. Vegetable production has known environmental impacts. However, the extent of its participation in sustainable production has not been adequately explored. This review sought to explore the spaciotemporal position of vegetables in a suite of existing sustainable agricultural practices, explore regional variations and discover lessons that can guide the future of vegetable production. There are regional differences regarding sustainable production practices and the associated barriers to their adoption. Generally, sustainable agricultural practices with a societal history in a region tend to be successful, unlike when they are “new” innovations. The major barriers to sustainable agricultural practices in vegetable production are economy-related (total investment cost) and crop-related and are also related to the technology transmission approaches. Unfulfilled expectations and a lack of community participation in technology development are noted challenges, which have led to dis-adoption. A farmer-centered approach to technology promotion could help. Comparatively, southern Africa has the most challenges in the adoption of sustainable agricultural practices. From the lessons learned from other regions, agroecology in vegetable cultivation is not unachievable in Africa. The projected challenges mean that sustainable vegetable production is inevitable.
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The Status of Vegetables Research in Malawi, Capacity, Progress, Gaps, and Way Forward—A Scoping Review "jointly worked" 査読あり 国際共著 国際誌
Dickson Mazibuko, Hiromu Okazawa, Hiroko Gono, Sarvesh Maskey
Agricultural Sciences 14 269 - 297 2023年02月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Scientific Research Publishing Inc.
Vegetables are key to nutrition and economic security, especially for developing societies. Research in vegetables has been historically key. From early domestication efforts to modern-day breeding and value addition, research has enabled vegetable productivity to support the nutritional and economic needs of societies. Impactful research, however, requires competent research capacity and a guiding framework, in a continuously changing socio-climatic world. Vegetable research appraisal in Malawi, especially regarding capacity, focus, and a guiding framework, is lacking. By using 5 search engines and 506 analyzed publications, this review sought to first examine the existing research capacity in Malawi and assess the vegetable research focus in terms of both value chain analysis themes and specific vegetable tax. This approach allowed for the isolation and flagging out of key emerging issues from existing research that positively contextualize future vegetable research direction in Malawi. It has been found that Malawi has adequate institutional and expertise capacity to further vegetable research. The identified challenges include local funding and infrastructural capacity to leverage donor funding. Three key emerging issues of climate change, modeling, and biofortification in vegetable crops have been identified. It is suggested that, with Malawi facing the climate change challenge, research focus in these areas, will enhance not only nutritional and economic security, but also overall climate change readiness. Key to climate change readiness is the involvement of indigenous vegetable production. As a package, vegetable cultivation can play a critical role in contributing to the achievement of pillar 1 of the Malawi vision 2063, which seeks to leverage agricultural productivity and commercialization with a focus on climate change resilience.
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Xiaoxun Huang, Kiichiro Hayashi, Minoru Fujii, Ferdinando Villa, Yuri Yamazaki, Hiromu Okazawa
Renewable Energy 205 293 - 304 2023年01月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Elsevier
Small hydropower has attracted extensive interest as a clean technology. This study first identified possible sites of small hydropower plants with estimated capacity, and then utilized resources time footprint as a novel way to evaluate the impact of small hydropower plants on the aspects of materials, CO2, labor, and land. Resources time footprint is a sustainability indicator that uses a uniform time unit (years). It assesses whether the usage of resources exceeds the amount allocated to different people and generations. The smaller the value of resources time footprint, the more environmentally friendly is the process. Preferential locations for small hydropower in Dan River were specified, with a potential capacity ranging from 273 to 1175 kW. Resources time footprint of copper is 8.9–47.3 times as large as that of steel. Resources time footprint of CO2 emissions is much smaller than that of other aspects, revealing that small hydropower has a great potential to mitigate the greenhouse effect. The overall resources time footprint decreases with an increase in the installed capacity. The methodology proposed in this study can be used to identify the ideal locations for setting up small hydropower plants in other regions as well.
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Assessment of Three Automated Identification Methods for Ground Object Based on UAV Imagery "jointly worked" 査読あり 国際共著 国際誌
Ke Zhang, Sarvesh Maskey, Hiromu Okazawa, Kiichiro Hayashi, Tamano Hayashi, Ayako Sekiyama, Sawahiko Shimada and Lameck Fiwa
Sustainability 14 ( 21 ) 2022年11月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：MDPI
This study compared three classification methods: A. NDVI threshold, B. RGB image-based machine learning, and C. object-based image analysis (OBIA). Method A was the least time-consuming and could identify vegetation and soil with high accuracy (user’s accuracy > 0.80), but had poor performance at classifying dead vegetation, plastic, and metal (user’s accuracy < 0.50). Both Methods B and C were time- and labor-consuming, but had very high accuracy in separating vegetation, soil, plastic, and metal (user’s accuracy ≥ 0.70 for all classes). Method B showed a good performance in identifying objects with bright colors, whereas Method C showed a high ability in separating objects with similar visual appearances. Scientifically, this study has verified the possibility of using the existing classification methods on identifying small ground objects with a size of less than 1 m, and has discussed the reasons for the different accuracy of the three methods. Practically, these results help users from different fields to choose an appropriate method that suits their target, so that different wastes or multiple resources can be monitored at the same time by combining different methods, which contributes to an improved integrated resource management system.
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Ke Zhang, Hiromu Okazawa, Kiichiro Hayashi, Tamano Hayashi, Lameck Fiwa and Sarvesh Maskey
Sustainability 14 ( 15 ) 1 - 21 2022年08月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
In this research, 88 GCP patterns have been validated and compared at an
18 ha farm. Results show that the patterns with GCPs distributed evenly around the field provided the best calibration (RMSE = 0.15 m). If this kind of pattern is not achievable because of obstructions, patterns with GCPs distributed evenly around half of the field or forming an evenly distributed triangle can provide moderate accuracy (RMSE = 0.18 m and 0.43 m, respectively). Patterns with GCPs forming a straight line yielded the worst accuracy (RMSE = 2.10 m). This shows that GCP distributions of a two-dimensional shape, even if the surrounding area is small, are better calibrated than a long, straight line. These results strongly suggest that appropriate GCP distribution patterns in the study areas will provide satisfactory accuracy for constructing integrated monitoring systems of diverse resources. -
Emmanuel Okiria, Hiromu Okazawa, Keigo Noda, Yukimitsu Kobayashi, Shinji Suzuki and Yuri Yamazaki
Hydrology 9 ( 5 ) 2022年05月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：MDPI
The prediction of hydrological phenomena using simpler hydrological models requires less computing power and input data compared to the more complex models. Ordinarily, a more complex, white-box model would be expected to have better predictive capabilities than a simple grey box or black-box model. But complexity may not necessarily translate to better prediction accuracy or might be unfeasible in data scarce areas or when computer power is limited. Therefore, the shift of hydrological science towards the more process-based models needs to be justified. To answer this, the paper compares 2 hydrological models: (a) the simpler tank model; and (b) the more complex TOPMODEL. More precisely, the difference in performance between tank model as a lumped model and the TOPMODEL concept as a semi-distributed model in Atari River catchment, in Eastern Uganda was conducted. The objectives were: (1) To calibrate tank model and TOPMODEL; (2) To validate tank model and TOPMODEL; and (3) To compare the performance of tank model and TOPMODEL. During calibration, both models exhibited equifinality, with many parameter sets equally likely to make acceptable hydrological simulations. In calibration, the tank model and TOPMODEL performances were close in terms of ‘Nash-Sutcliffe efficiency’ and ‘RMSE-observations standard deviation ratio’ indices. However, during the validation period, TOPMODEL performed much better than tank model. Owing to TOPMODEL’s better performance during model validation, it was judged to be better suited for making runoff forecasts in Atari River catchment.
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Plant Growth and Fruit Quality of Tomato (Solanum lycopersicum) Using Advanced Treated Water in Hydroponics "jointly worked" 査読あり 国際共著 国際誌
Antonio Perez Fuentes, Kazuha Wakasugi, Sarvesh Maskey, Dickson M. Mazibuko, Takahiko Nakamura, Hiroyuki Oshima, Taku Kato, Ayako Sekiyama and Hiromu Okazawa
International Journal of Environmental and Rural Development 15 ( 2 ) 123 - 128 2024年12月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Institute of Environmental Rehabilitation and Conservation (ERECON)
International Journal of Environmental and Rural Development
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A Multispecies Growth and Yield Performance Comparison of Vegetables Cultivated Under Hydroponics Using Sewage Wastewater "jointly worked" 査読あり 国際共著 国際誌
Dickson Mgangathweni Mazibuko, Antonio Perez Fuentes, Kazuha Wakasugi, Sarvesh Maskey, Takahiko Nakamura and Hiromu Okazawa
International Journal of Environmental and Rural Development 15 ( 2 ) 167 - 173 2024年12月
担当区分：最終著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Institute of Environmental Rehabilitation and Conservation (ERECON)
Reusing sewage wastewater for vegetable cultivation is becoming a solution to sustainable water utilization, particularly in water-scarce regions. Using two types of sewage wastewater, Biologically Treated Water (BTW) and Chlorine Disinfected Water (CDW), and tap water, this study aimed at making a comparison of and understanding the yield performance and chlorophyll content in three vegetables, Phaseolus vulgaris (common beans), Brassica rapa var. perviridis (komatsuna), and Solanum lycopersicum (tomato), grown under hydroponics. The experiment was carried out in the hydroponics greenhouse within the Yokohama Wastewater Reclamation Center, between May 2023 and August 2023. We used a Nutrient Film Technique (NFT) hydroponic system supplied with BTW, CDW, and tap water. The three water types served as our treatments. The plants were grown to maturity at a controlled water temperature. In comparing vegetable yield, an ANOVA test demonstrated significant differences among the treatments for common beans, komatsuna, and tomatoes. The Post hoc test showed significantly higher chlorophyll content for common beans and tomatoes grown in tap water, compared to BTW and CDW. Regarding yield, common beans performed best in the tap water hydroponic system, while tomato and komatsuna performed best in the BTW and CDW hydroponic systems. Results indicate a vegetable differential preference for the three water types used. These three vegetables can thus be cultivated concurrently. Research on the safety of vegetables grown in sewage wastewater and the economic feasibility of using treated sewage wastewater for vegetable production is urged before upscaling this technology.
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Effects of LED Lighting and Media on Vitamin C and Phenol Content in Ethiopian Kale (Brassica carinata) Microgreens "jointly worked" 査読あり 国際共著
Ruth Maru, John Wesonga, Dickson Mazibuko, Satoko Akiyama, Ayako Sekiyama, Shotaro Kawakami, Sarvesh Maskey, Agnes Kavoo, Johnstone Neondo and Hiromu Okazawa
International Journal of Environmental and Rural Development 15 ( 2 ) 151 - 156 2024年12月
担当区分：最終著者, 責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Institute of Environmental Rehabilitation and Conservation (ERECON)
Microgreens are innovative vegetable products related to their novelty and healthpromoting benefits. However, growth media and light conditions affect microgreens' nutritional content, which may limit their production in rural community settings. Brassica carinata is an essential local Kenyan vegetable, but its production and full utilization are limited by its early maturity. The potential of using B. carinata as a microgreen would be an excellent alternative production technique to minimize its early maturity limitation. This study investigated the influence of white and blue light on Vitamin C and phenol content in B. carinata microgreens grown using sand and cocopeat. B. carinata microgreens were grown for 14 days in a growth chamber using plastic punnet containers filled with cocopeat and sand under white and blue light. The capillary wick watering technique was used for irrigation. Temperature and relative humidity were monitored and maintained at 26°C± 2, and 60%, respectively. The photoperiod and intensity of light were also maintained at 12 hr Ⓒ ISERD 151 and 160 ± 2.5 µmol m−2s−1) respectively. After 14 days, microgreens were harvested and freeze-dried to analyze Vitamin C and phenol content. And. Data was subjected to ANOVA and was separated by Tukey’s multiple comparison test. Results indicated that light had no significant effect on B. carinata microgreens phenol content. However, microgreens grown in locally available sand showed statistically higher amounts of phenol content than those grown using cocopeat. For vitamin C content, media and light had no significant effect. Our results show that sand medium can be used equally to produce microgreens with higher phenol content for Brassica carinata.
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Development Challenges and Directions of Climate Change Measures in Paddy Agriculture in Southeast Asia 査読あり 国際誌
Hiromichi Kitada, Maskey Sarvesh, Taro Izumi, Hiromu Okazawa
International Journal of Environmental and Rural Development 15 ( 2 ) 143 - 150 2024年12月
担当区分：最終著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Institute of Environmental Rehabilitation and Conservation (ERECON)
Institute of Environmental Rehabilitation and Conservation (ERECON)
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Evaluation of Soil Micronutrients Across Selected Land Use Types in Chembe Enclave Village, Lake Malawi National Park "jointly worked" 査読あり 国際共著 国際誌
Placid Mpeketula, Dickson M. Mazibuko, Hiroko Gono, Lameck Fiwa, Sarvesh Maskey and Hiromu Okazawa
International Journal of Environmental and Rural Development 15 ( 2 ) 136 - 142 2024年12月
担当区分：最終著者, 責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
Knowledge and management of soil micronutrients are vital for maximizing crop production, ecosystem health, functionality, and sustainability. This is especially relevant for the soils of Chembe enclave village, located within Lake Malawi National Park (LMNP), a world heritage site. This study obtained micronutrient baseline data for soils across various land use types and provides benchmark data for long-term monitoring and management. Local soil was measured for the concentration of a panel of micronutrients using Atomic Absorption Spectrometry (AAS) after acid block digestion with a mixture of concentrated nitric acid (70% HNO3) and Hydrogen peroxide (30% H2O2). Measured micronutrients included zinc (Zn), manganese (Mn), copper (Cu), iron (Fe), and selenium (Se). Soil samples were obtained from five different land use types, including community gardens, farmland, Dambo, bare land, and forest land at depths of 0-5 cm and 5 -20 cm. Results indicated that land use type and soil depth are essential factors impacting micronutrient concentrations. Mean soil Zn and Mn concentrations were significantly higher in the community garden (1.51 and 663 mg/kg, respectively) in the topsoil compared to the rest of the land use types (p<0.0001). On the other hand, topsoil from the forest had significantly higher levels of Cu and Fe (3.7 and 329 mg/kg respectively). The maize farmland had the highest concentrations of Se (0.28 mg/kg), while the Dambo and the community garden had the lowest levels (0.01 mg/ kg). These findings suggest that micronutrient levels are tightly linked to land use type and soil depth. Further research should investigate the impacts of micronutrient levels and changes on crop productivity and broader ecosystem-wide implications at multiple scales from the enclave village, across LMNP, and the region as a whole.
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環境影響評価で対象事業による騒音増加を統計的に評価する方法－統計的な確率評価を採用する提案－
内田 英夫, 岡澤 宏
環境アセスメント学会誌 22 ( 2 ) 32 - 38 2024年08月
記述言語：日本語 出版者・発行元：環境アセスメント学会
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Crop Growth Model for Hydroponic Cultivation of <i>Solanum lycopersicum </i>(Tomato) in a Semi-automated System
PEREZ-FUENTES ANTONIO, MASKEY SARVESH, MAZIBUKO DICKSON M., OKAZAWA HIROMU, NAKAMURA TAKAHIKO, SEKIYAMA AYAKO
International Journal of Environmental and Rural Development 15 ( 1 ) 35 - 40 2024年
記述言語：英語 出版者・発行元：Institute of Environmental Rehabilitation and Conservation, Research Center
<p>Hydroponics can be integrated into Controlled Environment Agriculture (CEA), in combination with greenhouses. They can successfully optimize the use of fertilizers and water for arid zones. Elevated costs of this type of agriculture lead farmers to implement semiautomated systems and use recyclable materials to stabilize plant productivity. This paper discusses the different growth ratios of tomato plants estimated with logistic curves when tap water with fertilizer (T1), Oxidixed Water-OW [reclaimed water] (T2), and Disinfected Tertiary Recycled Water- DTRW [renewable water] (T3) are used; additionally, a new module is presented to avoid underestimation of plant height when fertilization is carried out at the flowering stage. This model was adapted only for treatment 1. Logistic curves were created with low RMSE values using the least-square method. Despite presenting better mass volume and fruit quantity in OW [reclaimed water] treatment at the final stage of the plant, a t-test revealed that there is not a significant difference among treatments of OW and DTRW [renewable and reclaimed water] for the height of plants. The adjustment of a logistic equation with the inclusion of a linear module allowed to decrease in the RMSE from 73 to 21 mm.</p>
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Kiseki Kurashina, Sarvesh Maskey, Dickson M. Mazibuko and Hiromu Okazawa
International Journal of Environmental and Rural Development 14 ( 2 ) 20 - 26 2023年12月
担当区分：最終著者, 責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Institute of Environmental Rehabilitation and Conservation (ERECON)
Climate change poses a challenge to irrigation water supply, especially in the case of the continuous flood irrigation method (CF). Alternate wetting and drying irrigation (AWD) is a method of rice cultivation widely used as a mitigation measure for water consumption, without reducing yields. To better promote AWD in areas where water scarcity occurs in the future, it is necessary to quantify the impact of AWD on growth. The objective of this study was to evaluate the impact of AWD on rice growth under AWD irrigation using logistic curves. Subsequent analysis demonstrated that by using AWD, irrigation capacity was reduced by approximately 19%. Additionally, multiple regression analysis indicated that temperature, sunshine hours, and relative humidity had significant effects on plant growth. A growth model (RMSE = 2.98 cm to 3.82 cm) was generated by applying a logistic curve where the daily mean integrated values of meteorological data as explanatory variables and plant growth as the objective variable. Using the model, it was found that AWD increased the growth rate of the rice plant; however, rice plant growth in the initial period was lower compared to CF.
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Saki Higuchi, Honami Ono, Hiroaki Honda, Sarvesh Maskey, Akira Kurosawa, Toshihiro Suzuki, Nobuyuki Takahashi, Hiromu Okazawa and Kouji Takeda
International Journal of Environmental and Rural Development 14 ( 1 ) 98 - 105 2023年06月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Institute of Environmental Rehabilitation and Conservation
The crayfish (Procambarus clarkii) is an invasive alien species consumed as a food source worldwide. However, there is an extremely low demand for it as a food resource in Japan, and it is typically targeted for extermination. One reason for the lack of progress in considering crayfish a sustainable food resource is limited education on the issue during secondary education programs. It is well known that astaxanthin is the pigment responsible for the body color of common red crayfish and crustaceans such as shrimp and crabs. At the same time, while there are ample study materials on plant pigments in the science education curriculum in junior high and high schools in Japan, there are no such materials to our knowledge that focus on animal pigments. Therefore, this research sought to develop teaching materials to deepen understanding of color as a food component of crayfish through an experiment involving extracting and separating their pigments. Using pigments extracted from red crayfish exoskeletons, we developed experimental teaching materials to observe astaxanthin by employing thin-layer chromatography and high-performance liquid chromatography. In addition, an experiment was conducted to observe the effect of different foods on crayfish body color. For the experiment, food was developed to make crayfish bodies white (decolorized) and orange. When the decolorized crayfish were fed norbixin or bixin, which are components of the orange annatto pigment, norbixin tended to accumulate as orange in the exoskeleton more than bixin based on the apparent body color change, color extraction from images, and thin-layer chromatography. These findings are expected to be useful for science and nutrition education, supporting the development of the students’ awareness and understanding of crayfish as a food resource.
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Dickson M. Mazibuko, Lameck Fiwa, Maskey Sarvesh and Hiromu Okazawa
International Journal of Environmental and Rural Development 14 ( 1 ) 170 - 176 2023年06月
担当区分：最終著者, 責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Institute of Environmental Rehabilitation and Conservation
Understanding the rainfall dynamics of a nation/region is key to decision-making, especially regarding agriculture within protected areas. This study focused on the area of Cape Maclear and the adjacent villages located within the Lake Malawi National Park (LMNP). By gaining insight into how communities whose agricultural activities interact with protected areas operate, we can gain insight into the long-term sustainability of the LMNP. This study aimed to assess the historical rainfall dynamics for Cape Maclear using 35-year annual rainfall and temperature data. Rainfall trends were established and compared with recorded events. The results indicated that Cape Maclear rainfall trends resonate with reported national drought events, though with variations. This provides a proxy possibility of making localized predictions of such events. Analysis of the return period shows annual rainfall of between 500900 mm occurs every 2-3 years, indicating no significant shifts from what has been observed in the past. Due to the sensitivity and fragility of the LMNP ecosystem, there is a need to design local solutions for the communities living within the park to enable them to better prepare for future climatic shocks, especially rainfall inadequacies.
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Sarvesh Maskey, Hiyori Iseki, Kiseki Kurashina, Ke Zhang and Hiromu Okazawa
International Journal of Environmental and Rural Development 14 ( 1 ) 119 - 125 2023年06月
担当区分：最終著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Institute of Environmental Rehabilitation and Conservation
Monitoring hydro-structural infrastructure is becoming an important and challenging issue. In Japan, there are an increasing number of aging hydro-structural facilities, which need to be inspected to guarantee their strength and durability function. Unmanned Aerial Vehicle (UAV) photogrammetric images have been used in the detection of structural deterioration of various infrastructure. However, there is a challenge in determining the optimum flying conditions (altitude, angle of camera, and flying patterns) of UAVs for obtaining images. The designs, shapes, and sizes of hydro-structural facilities also pose a challenge for obtaining ideal images. In this study, verification of various flying conditions for producing images and 3D models was proposed for water gates and open surface water channels. Additionally, an evaluation method for the images and 3D models was suggested. In this study, UAV was used for visual inspection and obtaining the image of the water gate and open surface water channel at the Tone diversion gate in Saitama, Japan. Various geometric patterns were pasted on the surface and walls of the structures to evaluate the detection of the patterns with the images taken from UAVs at different flying conditions. The obtained ortho-mosaic images were processed by a PIX4D mapper to obtain a point cloud-based 3D model and were compared with the actual measurements of the patterns. The results of the study suggested that altitude and camera angles affected the quality of images significantly. Cameras at lower angles provided better images, although cameras at high altitudes with wider angles also demonstrated a high degree of efficiency. The circular flying pattern generated satisfactory results, where flyovers were conducted multiple times while changing altitudes and angles of the camera. Additionally, this study proposes a method named “leveling” for the evaluation of images and 3D models.
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National versus Local Climatic Variability and Implications for Communities in Protected Areas: The Case of Lake Malawi National Park "jointly worked" 査読あり 国際共著
Dickson M. Mazibuko, Lameck Fiwa, Maskey Sarvesh and Hiromu Okazawa
International Journal of Environmental and Rural Development 14 ( 1 ) 170 - 176 2023年06月
担当区分：最終著者, 責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Institute of Environmental Rehabilitation and Conservation (ERECON)
Understanding the rainfall dynamics of a nation/region is key to decision-making, especially regarding agriculture within protected areas. This study centers around Cape Maclear and the adjacent villages located within the Lake Malawi National Park (LMNP). By gaining insight into how communities whose agricultural activities interact with protected areas operate, we can determine the long-term viability of the LMNP's sustainability. This study aimed to assess the historical rainfall dynamics for Cape Maclear using 35-year annual rainfall and temperature data. Rainfall trends were established and compared with recorded events. It has been found that Cape Maclear rainfall trends resonate with reported national drought events, though with variations. This provides a proxy possibility of making localized predictions of such events. Analysis of the return period shows annual rainfall of between 500900 mm occurs every 2-3 years, indicating no significant shifts from what has been observed in the past. Due to the sensitivity and fragility of the LMNP ecosystem, there is a need to design local solutions for the communities living within the park to enable them to better prepare for future climatic shocks, especially rainfall inadequacies.
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Verifying Optimum Flying Conditions for UAV Photogrammetry in Assessing Hydro-structural Facilities
MASKEY SARVESH, ISEKI HIYORI, KURASHINA KISEKI, ZHANG KE, OKAZAWA HIROMU
International Journal of Environmental and Rural Development 14 ( 1 ) 119 - 125 2023年
記述言語：英語 出版者・発行元：Institute of Environmental Rehabilitation and Conservation, Research Center
<p>Monitoring hydro-structural infrastructure is becoming an important and challenging issue. In Japan, there are an increasing number of aging hydro-structural facilities, which need to be inspected to guarantee their strength and durability function. Unmanned Aerial Vehicle (UAV) photogrammetric images have been used in the detection of structural deterioration of various infrastructure. However, there is a challenge in determining the optimum flying conditions (altitude, angle of camera, and flying patterns) of UAVs for obtaining images. The designs, shapes, and sizes of hydro-structural facilities also pose a challenge for obtaining ideal images. In this study, verification of various flying conditions for producing images and 3D models was proposed for water gates and open surface water channels. Additionally, an evaluation method for the images and 3D models was suggested. In this study, UAV was used for visual inspection and obtaining the image of the water gate and open surface water channel at the Tone diversion gate in Saitama, Japan. Various geometric patterns were pasted on the surface and walls of the structures to evaluate the detection of the patterns with the images taken from UAVs at different flying conditions. The obtained ortho-mosaic images were processed by a PIX4D mapper to obtain a point cloud-based 3D model and were compared with the actual measurements of the patterns. The results of the study suggested that altitude and camera angles affected the quality of images significantly. Cameras at lower angles provided better images, although cameras at high altitudes with wider angles also demonstrated a high degree of efficiency. The circular flying pattern generated satisfactory results, where flyovers were conducted multiple times while changing altitudes and angles of the camera. Additionally, this study proposes a method named "leveling" for the evaluation of images and 3D models.</p>
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Impact Evaluation of Climate Change on Disaster Risk of Forested Watershed Rivers in Snowy Regions using SWAT+
KIKUCHI SHOTARO, MASKEY SARVESH, OKAZAWA HIROMU, AZAEL MAY CUEVAS SERGIO, OBA MAKOTO, NAKAMURA SHOGO, HAYASHI SEIJI
International Journal of Environmental and Rural Development 14 ( 2 ) 100 - 106 2023年
記述言語：英語 出版者・発行元：Institute of Environmental Rehabilitation and Conservation, Research Center
<p>In this study, we analyzed the reduction in snowfall and snowmelt under climate change scenarios in a cold snowy region. Also, we clarified the causal relationship between deforestation and disaster risk in watershed management in Mishima Town, Fukushima Prefecture. We used SWAT+ to conduct simulations; the SWAT+ model of Mishima town was built in a previous study, and its reproducibility was verified by NSE and RMSE by correcting parameters and using auto-calibration. The latest set of models from the CMIP6, also used in the 6th Impact Assessment Report of the IPCC and statistically downscaled scenarios in Japan developed by the Center for Climate Change Adaptation, National Institute for Environmental Studies, was adapted to simulate climate change scenarios. The Emission Scenarios are based on RCP8.5, which has been used in future climate change discussions (i.e., the assumption that greenhouse gases will continue to increase without any global warming countermeasures). We simulated the end of the 21<sup>st</sup> century situation. As the result of the simulation, the RCP8.5 scenario showed a significant decrease in snowfall and snowmelt, with only one day of snowfall of RCP8.5 from January to March. The potential for early spring snowmelt water availability of RCP8.5 at the end of the 21st century could have been much higher. Additionally, we conducted a simulation of deforestation. We assumed that 5 % of the forested area became agricultural land due to deforestation. Simulation results indicated that the surface flow under deforestation conditions was 145.1 mm, a 7 % increase over the surface flow of the original forest prior to deforestation (135.1 mm). Heavy and long-lasting rainfall showed no difference in water storage function between the two cases, but 5 % deforestation was shown to increase river discharge at the beginning of a rainfall event.</p>
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Evaluation of the Effect of Alternate Wetting and Drying Irrigation on the Growth of Paddy Rice Plant Height Using a Logistic Model
KURASHINA KISEKI, MASKEY SARVESH, M. MAZIBUKO DICKSON, OKAZAWA HIROMU
International Journal of Environmental and Rural Development 14 ( 2 ) 20 - 26 2023年
記述言語：英語 出版者・発行元：Institute of Environmental Rehabilitation and Conservation, Research Center
<p>Climate change poses a challenge to irrigation water supply, especially in the case of the continuous flood irrigation method (CF). Alternate wetting and drying irrigation (AWD) is a method of rice cultivation widely used as a mitigation measure for water consumption, without reducing yields. To better promote AWD in areas where water scarcity occurs in the future, it is necessary to quantify the impact of AWD on growth. The objective of this study was to evaluate the impact of AWD on rice growth under AWD irrigation using logistic curves. Subsequent analysis demonstrated that by using AWD, irrigation capacity was reduced by approximately 19 %. Additionally, multiple regression analysis indicated that temperature, sunshine hours, and relative humidity had significant effects on plant growth. A growth model (RMSE = 2.98 cm to 3.82 cm) was generated by applying a logistic curve where the daily mean integrated values of meteorological data as explanatory variables and plant growth as the objective variable. Using the model, it was found that AWD increased the growth rate of the rice plant; however, rice plant growth in the initial period was lower compared to CF.</p>
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Educational Material Research on the Color of Crayfish for Conversion to Edible Resources
HIGUCHI SAKI, ONO HONAMI, HONDA HIROAKI, MASKEY SARVESH, KUROSAWA AKIRA, SUZUKI TOSHIHIRO, TAKAHASHI NOBUYUKI, OKAZAWA HIROMU, TAKEDA KOUJI
International Journal of Environmental and Rural Development 14 ( 1 ) 98 - 105 2023年
記述言語：英語 出版者・発行元：Institute of Environmental Rehabilitation and Conservation, Research Center
<p>The crayfish (<i>Procambarus clarkii</i>) is an invasive alien species consumed as a food source worldwide. However, there is an extremely low demand for it as a food resource in Japan, and it is typically targeted for extermination. One reason for the lack of progress in considering crayfish a sustainable food resource is limited education on the issue during secondary education programs. It is well known that astaxanthin is the pigment responsible for the body color of common red crayfish and crustaceans such as shrimp and crabs. At the same time, while there are ample study materials on plant pigments in the science education curriculum in junior high and high schools in Japan, there are no such materials to our knowledge that focus on animal pigments. Therefore, this research sought to develop teaching materials to deepen understanding of color as a food component of crayfish through an experiment involving extracting and separating their pigments. Using pigments extracted from red crayfish exoskeletons, we developed experimental teaching materials to observe astaxanthin by employing thin-layer chromatography and high-performance liquid chromatography. In addition, an experiment was conducted to observe the effect of different foods on crayfish body color. For the experiment, food was developed to make crayfish bodies white (decolorized) and orange. When the decolorized crayfish were fed norbixin or bixin, which are components of the orange annatto pigment, norbixin tended to accumulate as orange in the exoskeleton more than bixin based on the apparent body color change, color extraction from images, and thin-layer chromatography. These findings are expected to be useful for science and nutrition education, supporting the development of the students’ awareness and understanding of crayfish as a food resource.</p>
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Ke Zhang, Ayako Sekiyama, Hiromu Okazawa, Yuri Yamazaki, Kiichiro Hayashi, Osamu Tsuji, Masahiro Akimoto
International Journal of Environmental and Rural Development 13 ( 2 ) 137 - 143 2022年12月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：特定非営利活動法人環境修復保全機構 研究センター
This research tested the capability of 3D point cloud in estimating plant height and biomass volume of pasture grass, and compared the results with CSMs. UAV photography were conducted at the experimental field of Obihiro University of Agriculture and veterinary Medicine, Hokkaido, Japan, 2019. The biomass volume estimated by DSM and point cloud have no significant difference, showing that DSM and point cloud have the same performance at estimating biomass volume of grass. In the case that only the simple value data is required, the point cloud data is recommended.
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Shotaro Kikuchi, Hiromu Okazawa, Sarvesh Maskey, Sergio Azael May Cuevas, Makoto Oba, Shogo Nakamura and Seiji Hayashi
International Journal of Environmental and Rural Development 13 ( 2 ) 105 - 112 2022年12月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Institute of Environmental Rehabilitation and Conservation (ERECON)
Utilizing a hydrological model for analyzing the hydrological cycle throughout a river basin is an effective method to assess the impacts of climate change on water resource management, flood control, and agriculture. Although there are various hydrological models developed, in this study, Soil and Water Assessment Tool plus (SWAT+) is used as it is widely used and predicts the impacts of land use management in watershed management. SWAT+ is a complex quasi−physically based water quality model relying on numerous input files and parameters, thus this poses a great challenge when attempting to set up the model manually, and there is a lack of information regarding the validation of SWAT+'s of performance for snow accumulation and melting processes. The objective of this study is to estimate long-term streamflow in forested watershed in snowy region using SWAT+, and to verify the accuracy of the estimation and to confirm the improvement of the accuracy by adjusting parameters. In order to improve the accuracy of simulation, “the saturated hydraulic conductivity of soil layer” and “the available water capacity of soil layer” were adjusted for parameter of soil moisture content, moreover, we adjusted parameter of temperature of “snowfall” and “snowmelt”. Finally, “the time of lateral flow travel” which is difficult to measure was calibrated using the auto-calibration of SWAT+. As the results, it was difficult to achieve high accuracy in predicting river discharge with the default parameters of SWAT+, but some months (May-Oct) could be accurately predicted after adjusting parameters using measured data and conducting the auto-calibration. On the other hand, simulations during snowfall and snowmelt term (Dec-Mar) were less accurate and need to set more detailed conditions.
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Evaluation of Sediment Trapping Capacity by Geotextile for Erosion Control "jointly worked" 査読あり 国際誌
Sarvesh Maskey, Takanori Kaneko, Hiromu Okazawa, Antonio Perez Fuentes, Sachiko Watanabe, Kazuhiro Tazaki and Takahiro Sasaki
International Journal of Environmental and Rural Development 13 ( 2 ) 99 - 104 2022年12月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Institute of Environmental Rehabilitation and Conservation (ERECON)
Heavy precipitation events induce sediment transport resulting in soil loss, aggravating erosion. Geotextile for erosion control, offers environmentally friendly benefits and have lower costs than other physical structures. Recently, there has been interest in high performance and multifunctional geotextiles. In this study, evaluation was made to investigate the capacity of geotextile in sediment trapping. A runoff experiment was conducted, using a runoff plot using two types of geotextiles, having dimensions of 100 and 10 cm length and breadth respectively. Slope for the runoff plot was created at 0.859 degrees. Four treatments, for each geotextile were made. The treatments were, 1) no folds, 2) folds for 25 cm of the runoff plot, 3) folds for 50 cm of runoff plot, 4) folds for 100 cm of the runoff plot. Muddy water suspension having Suspended Solid (SS) of 25000 mg/L was discharged on the treatments. SS of runoff and infiltered suspension were analyzed. According to the results, both geotextiles were effective in sediment trapping. For Sample A, SS decreased by 88.1%, 97.16%, 99.14% and 99.15% in no folds, 25 cm fold, 50 cm fold and 100 cm fold treatment respectively from the initial SS of the muddy water suspension. Whereas, for Sample B, SS decreased by 87.3%, 91.87%, 98.74% and 98.34% in no folds, 25 cm fold, 50 cm fold and 100 cm fold treatments respectively. Additionally, SS significantly decreased in folded treatments for both geotextiles. Accordingly, it was established that geotextile can function for erosion controlling with increase in folds. However, further research is required to understand the intensity of discharge on geotextiles for sediment trapping capacity for future applications.
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Evaluating Ion Exchange Capacity of Molten Slag for Hydroponic System "jointly worked" 査読あり 国際誌
13 ( 1 ) 143 - 146 2022年06月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Institute of Environmental Rehabilitation and Conservation
Hydroponic farming promotes high-efficiency water, fertilizers, and high productivity under a controlled environment. However, the use of this system needs consistent application of fertilizers, increasing the cost of operations. Molten Slag (MS), a waste from the Municipal Solid Waste Incineration has essential nutrients that can be used as fertilizer. The objective of this study was to clarify the releasing process of nutrients by molten slag to be applied as a substrate in hydroponic system. For this, anion and cation contents of three varieties of Molten Slag (MS1, MS2, MS3) were determined in the laboratory by a shaking method. The nutrient content, P2O5, K2O, MgO and CaO were in MS1, MS3 and MS2. The quantification ion released was performed at 1, 6, 12 and 24 hours. It was observed that MS3 had performed the best condition in the releasing process of K+, Mg+, SO42- and Cl-. Although MS1 had higher nutrient content, MS3 released higher contents of those minerals among the samples. According to the result of this study, it was confirmed that MS3 has a high potential for hydroponic farming.
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Relationship between NDVI and Canopy Cover Sensed by Small UAV under Different Ground Resolution "jointly worked" 国際誌
Ke Zhang, Hiromu Okazawa, Yuri Yamazaki, Kiichiro Hayashi, Osamu Tsuji
International Journal of Environmental and Rural Development 12 ( 2 ) 122 - 128 2021年12月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：特定非営利活動法人環境修復保全機構 研究センター
In this study, small UAVs took RGB and multispectral images of the experimental peanuts field in Hokkaido. Orthomosaic and reflectance map of the field were constructed using the UAV imagery and then were obtained CC and NDVI values with GIS software. CC was calculated as the green canopy area ratio, extracted from the orthomosaic using a GIS supervised classification tool. CC was compared with NDVI values under various resolutions of 0.50 m, 1.0 m, 2.5 m, 5.0 m, and 10 m. The NDVI showed a highly correlated linear relationship with CC under each ground resolution from 0.10 m to 10 m (R2 led a range of 0.88** to 0.94**). The shapes of NDVI and CC’s regression equations closely resembled each other, with the slopes of 1.06 to 1.11 and the intercepts of 0.247 to 0.250, respectively. From the result of ANCOVA, the UAV imagery resolution has no significant impact on NDVI and CC’s relationship. Although more irrelevant factors, such as soil and mulching seat, got included within one pixel of the images, the regression equations stayed the same with the increased ground resolution.
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Applicability of Tank Model in Mid-Sized Catchments in Eastern Uganda "jointly worked" 査読あり 国際誌
Emmanuel Okiria, Hiromu Okazawa, Yuri Yamazaki, Yukimitsu Kobayashi and Shinji Suzuki
International Journal of Environmental and Rural Development 11 ( 2 ) 32 - 38 2020年12月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：特定非営利活動法人環境修復保全機構 研究センター
ウガンダ東部の山間部にある農林地流域河川を対象に，直列4段のタンクモデルによる河川流量のシミュレーションを行った。そして，流量予測の精度は高く，河川流量を表面流と基底流の2種に分けることができ，河川水質の形成機構に寄与する重要なモデルであることを示した。
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Examination of Optimal Search Method of Unknown Parameters in Tank Model by Monte Carlo Method "jointly worked" 査読あり 国際誌
Koji Miwa, Kosuke Mukae, Hiromu Okazawa, Tadao Yamamoto, Takashi Inoue and Emmauel Okiria
International Journal of Environmental and Rural Development 11 ( 1 ) 1 - 7 2020年06月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：特定非営利活動法人環境修復保全機構 研究センター
北海道南西部の森林，草地を主体とする流域において，TANKMODELの適用を試みた。特に，TANKMODELによる流出解析に必要となる流出孔の係数などを決定する計算回数について検討した。
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Identifying the Minimum Number of Observed Rainfall Events Required for Optimal TOPMODEL Parameters in Mid-sized Equatorial Catchments "jointly worked" 査読あり 国際誌
Emmanuel Okiria, Hiromu Okazawa, Yuri Yamazaki, Yukimitsu Kobayashi and Shinji Suzuki
International Journal of Environmental and Rural Development 10 ( 2 ) 113 - 119 2019年12月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：International Society of Environmental and Rural Development
ウガンダ国東部の山間地流域において，水文流出モデルであるTOPMODELのパラメータ設定に必要な降雨イベント数を検討した。パラメータの数値決定に降雨イベントのデータ数が関係することを示した。
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Accuracy Verification of UAV-SfM Survey of Terrace Paddy Fields in a Hilly and Mountainous Area "jointly worked" 査読あり
Yuri Yamazaki, Hiromu Okazawa, Ayako Sekiyama and Tomonori Fujikawa
International Journal of Environmental and Rural Development 10 ( 1 ) 151 - 156 2019年06月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：nternational Society of Environmental and Rural Development
静岡県菊川市の千框棚田において，傾斜地に展開する水田を対象にUAV測量の精度を検証した。UAV測量では地上の既知点であるGCPを配置して，位置情報の補正を行う必要がある。一方，GCPの設置条件と測量精度について論じた報告は少ない。ここでは，GCPの設置数と配置がUAV測量の精度に及ぼす影響を検証した。
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GIS-based Analysis for the Energy Potential and Social Feasibility of Small-Scale Run-Off-River Hydropower in Yahagi River, Japan "jointly worked" 査読あり 国際誌
Yuri Yamazaki, Kiichiro Hayashi, Nobuko Kawaguchi, Hiromu Okazawa and Ferdinando Villa
International Journal of Environmental and Rural Development 10 ( 2 ) 133 - 140 2019年06月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：International Society of Environmental and Rural Development
愛知県，長野県を流域に持つ矢作川流域において，小水力発電のポテンシャル推計を行った。GISによる地形，河道，人口，配電施設，保護区などの複数データによる解析から，効率的に発電を行い導電できる発電適地の選定をする手法を確立した。
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Issues of Disaster Recovery Management and Application of GIS and UAV for Resilience in Agricultural Land and Infrastructure "jointly worked" 査読あり
Koji Miwa, Ayako Sekiyama, Toru Nakajima, Takahiko Kubodera, Chikahiro Egami and Hiromu Okazawa
International Journal of Environmental and Rural Development 9 ( 2 ) 114 - 121 2018年12月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：International Society of Environmental and Rural Development
熊本地震によって被災した農地の復旧対策には，UAVやGISによる管理手法が有効である。ここでは，行政を対象に，GISによる農地管理手法の有効性とUAVによる新たな管理手法の導入について地方自治体にアンケートを実施し，これらの導入に対する市来調査を行い問題点を明らかにした。
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Application of TOPMODELs for Assessment of Ecosystem Services: Regulating Service in Agricultural and Forest Watershed "jointly worked" 査読あり 国際誌
Kosuke Mukae, Koji Miwa, Hiromu Okazawa, Tadao Yamamoto, Takashi Inoue
International Journal of Environmental and Rural Development 9 ( 1 ) 43 - 50 2018年06月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：International Society of Environmental and Rural Development
生態系サービスのひとつである調整サービスの定性的評価を目的として，北海道の森林流域と農業流域を対象に洪水予測で用いられるTOPMODELの適用を試みた。TOPMODELは準分布型モデルでり，他軌道においても適用性が高いことが示された。また，５つのパラメータを用いて，調整サービスの違いを示すことができた。
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Influence of the agricultural land agglomeration to the nutrients of the river water in the Tokachi River basin "jointly worked" 査読あり
Yuri Yamazaki, Toshimi Muneoka, Hiromu Okazawa, Masato Kimura, Osamu Tsuji
Paddy and Water Environment 15 277 - 290 2017年04月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
北海道東部の十勝川水系を対象に，農業的土地利用である畑地と，森林との土地利用配置が河川の窒素・リン濃度に及ぼす影響を明らかにした。
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Ecosystem Service Assessment in Agricultural Watershed by using TOPMODEL "jointly worked" 招待あり 査読あり
Kosuke Mukae, Koji Miwa, Hiromu Okazawa, Tomonori Fujikawa
AGROFOR International Journal 2 ( 3 ) 27 - 36 2017年
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：University of East Sarajevo, Faculty of Agriculture
河川流量の変動予測モデルとして，TOPMODELが世界的に使われてきた。ここでは，単一土地利用ではなく，森林と草地が混在する複合型土地利用流域において，TOPMODELを土地利用頃に適用することで河川流量の予測精度を検討した。また，TOPMODELに適用するパラメータを用いて，森林と草地における洪水緩和機能の効果を検討した。
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直接水準測量と比較した GNSS 水準測量による 山間地における標高の最確値と標準偏差（共著） 査読あり
久保寺貴彦，岡澤宏，細川吉晴，松尾栄治
農業農村工学会論文集 84 ( 3 ) 1-331 - 1-342 2016年12月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
2014年4月，国土地理院が「日本のジオイド 2011」(Ver.1)を公開したことによって，3級水準測量相当のGNSS水準測量が全国的に実用化された。本研究では，長野県軽井沢町の水準点から 5 km ほど離れた標高 920 m ほどの山間地の 新点において，GNSS 水準測量および直接水準測量を実施して，それぞれ点検計算および厳密網平均計算を行って標高 値を比較検証した.また，GNSS 水準測量において，直接水準測量と比較した観測作業，「GPS のみ」と「GPS+GLONASS」 の差異が最確値と標準偏差に及ぼす影響，観測時間の差異が最確値と標準偏差に及ぼす影響を明らかにすることとした. この結果，GNSS 水準測量は，直接水準測量より安全かつ効率的に観測作業ができ，「GPS のみ」によって観測時間の差 異による最確値の変動を抑えられ，直接水準測量の成果に整合した標高値が得られることがわかった.
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Influence of Meteorological Variable Combinations on Reference Evapotranspiration Estimated by the FAO56 Penman-Monteith Method "jointly worked" 国際誌
Hiromu Okazawa, Yasushi Takeuchi
International Journal of Environmental and Rural Development 7 ( 2 ) 147 - 153 2016年12月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：International Society of Environmental and Rural Development
世界的に適用されている蒸発散推定モデルであるFAO56 Penman-Monteith Methodを活用して，福島県南相馬市において観測をした気象データを用いて，計算パラメータの組み合わせが推定精度に及ぼす影響を検討した。
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Proposed the Model for Estimation of Nitrogen Load in the Agro-Forestry Watershed "jointly worked" 査読あり
Yuri Yamazaki, Toshimi Muneoka, Hiromu Okazawa
International Journal of Environmental and Rural Development 7 ( 1 ) 148 - 153 2016年06月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：International Society of Environmental and Rural Development
本研究では，北海道十勝川流域を対象に，土地利用指標を取り入れた窒素負荷量の予測モデルについて検討をした内容である。
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Effects of Surveying Methods between GNSS and Direct Leveling on Elevation Values over Long Distance in Mountainous Area "jointly worked" 査読あり
Takahiko Kubodera, Hiromu Okazawa, Yoshiharu Hosokawa, Futoshi Kawana, Eiji Matsuo, Machito Mihara
International Journal of Environmental and Rural Development 7 ( 1 ) 62 - 69 2016年06月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：International Society of Environmental and Rural Development
本研究では，中山間地域における水準測量の精度について，GNSS測量との比較によって明らかにしたものである。
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Characteristics of the River Water Quality Under Base Flow Condition in the Tokachi River Basin, Japan "jointly worked" 査読あり
Yuri Yamazaki, Toshimi Muneoka, Hiromu Okazawa, Masato Kimura, Osamu Tsuji
International Journal of Environmental and Rural Development 7 ( 1 ) 154 - 159 2016年06月
記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：International Society of Environmental and Rural Development
北海道十勝川流域の複数河川において，平水時の河川水質特性をpH，BOD，SS，ECを指標に検討し，明らかにした論文である。
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Effectiveness of Clinker Ash in Removing Nitrate Nitrogen from Agricultural Waste Water ”jointly worked” 査読あり
Hitoshi YAMAMOTO, Hiromu OKAZAWA*, Yasushi TAKEUCHI, Machito MIHARA
Agriculture & Forestry 62 ( 1 ) 37 - 42 2016年
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
クリンカアッシュを用いた水質浄化システムの開発を目的とした研究成果のひとつで有り，クリンカアッシュはアンモニウム態窒素に加えて，硝酸態窒素の吸着能も有することを，室内におけるカラム試験によって明らかにした研究論文である。
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EVALUATION OF IMPACT OF EARTHQUAKE ON AGRICULTURE IN NEPAL BASED ON REMOTE SENSING "jointly worked" 査読あり 国際誌
Ayako SEKIYAMA, Kuang TING KUO, Maskey SARVESH, Sawahiko SHIMADA, Hiromu OKAZAWA, Koji MIWA, Machito MIHARA
AGROFOR International Journal 1 ( 1 ) 58 - 65 2016年
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌） 出版者・発行元：Faculty of Agriculture, University of East Sarajevo
2015年に発生したネパール国における地震災害について扱った。特に，農地の被害状況をリモートセンシング技術を用いて評価するとともに，USLE式を組み合わせることで農地災害の危険度を評価する手法について言及をした。
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Circumstances of Surveyor License Acquisition System in Japan "jointly worked" 査読あり
TAKAHIKO KUBODERA, HIROMU OKAZAWA, YOSHIHARU HOSOKAWA, MASAHIRO TASUMI, KATSUHIRO SASADA, EIJI MATSUO, MACHITO MIHARA
International Journal of Environmental and Rural Development 6 ( 1 ) 51 - 57 2015年06月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
日本において測量に関する資格の取得には幾通りかの方法がある。ここでは，専門学校，大学を通じた測量教育の問題点を検討し，現在必要とされている測量技術の知識の取得を行うための教育方法について明らかにした。
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Circumstances of Survey Education Conducted in Japanese Universities "jointly worked" 査読あり
TAKAHIKO KUBODERA, HIROMU OKAZAWA, YOSHIHARU HOSOKAWA, MASAHIRO TASUMI, KATSUHIRO SASADA, EIJI MATSUO, MACHITO MIHARA
International Journal of Environmental and Rural Development 6 ( 1 ) 46 - 50 2015年06月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
工学系の大学において測量学は必修の科目である。一方，測量技術は日進月歩で進化をしており，教育現場と実際に測量技術を必要とする現場とでは測量内容に差異が生じている。ここでは，現代の測量教育に関する問題点を指摘し，教育内容の改善について検討した。
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測量の資格制度と教育実態を踏まえたあたらしい測量学教材の開発（共著） 査読あり
久保寺貴彦, 細川吉晴, 岡澤宏, 笹田勝寛, 松尾栄治, 多炭雅博, 三原真智人
土木学会論文集H（教育） 71 ( 1 ) 18 - 27 2015年03月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
工学系大学では卒業と同時に測量士補の資格が得られる大学が多い。測量技術は日進月歩で進化しているが，大学で教える測量教育との差異も少なからず存在する。本研究では測量に関して大学教育で補うべき内容を抽出し，測量の資格制度と教育実態を踏まえた新しい教材の開発について検討した。
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NITROGEN ADSORPTION ABILITY IN CLINKER ASH AND UTILIZATION OF NITROGEN−ADSORBED CLINKER ASH TO PROMOTE VEGETATION GROWTH "jointly worked" 招待あり 査読あり
Hiromu OKAZAWA and Tomonori FUJIKAWA
Agriculture and Forestry 60 ( 4 ) 15 - 20 2014年12月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
火力発電所から排出される石炭灰の一種であるクリンカアッシュは年々排出量が増加しており，リサイクル材としての活用方法が求められている。本研究では，農業分野におけるクリンカアッシュの利活用について研究をしたものである。具体的には，農地から排出される窒素汚濁水の浄化を目的として，多孔質材であるクリンカアッシュの窒素吸着能を評価し，吸着した窒素を農業生産で再度利用できる物質循環システムの構築を目指したものである。
その他リンク： http://www.agricultforest.ac.me/paper.php?journal_id=185&id=2330
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Effects of Coastal Road Spacing on Deposition of Tsunami-Borne Sand "jointly worked" 査読あり
YOUKI MAEDA, HIROMU OKAZAWA, YASUSHI TAKEUCHI, TOMONORI FUJIKAWA, SHIGEYUKI MIYABAYASHI
International Journal of Rura and Environemntal Development 5 ( 1 ) 77 - 81 2014年04月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
沿岸域における津波対策として，防潮林，防潮堤，2線堤の組み合わせによる津波減衰効果を，室内の実験用開水路を用いてて人工的に津波を発生させて再現し，対策の効果を明らかにした内容である。
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凍結をともなう網走地域におけるマトリックポテンシャルの季節変動−誘電水ポテンシャルセンサの利用と凍土における浸透ポテンシャルの吟味-（共著） 査読あり
鈴木伸治，葛西拓也，三井ともみ，伊藤博武，岡澤 宏
土壌の物理性 126 51 - 62 2014年04月
記述言語：日本語 掲載種別：研究論文（学術雑誌）
北海道網走における畑地圃場において，冬期間を通じて土壌水分等の気象観測を行い，その結果から凍土におけるマトリックポテンシャルの変化を明らかにした内容である。
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Comparison of Inoculated Eri Cocoon and Eco-block for Pollutant Removal "jointly work" 査読あり
Carlos Onan Mendoza Tovar, Kumiko Kawabe, Hiromu Okazawa and Machito Mihara
International Journal of Environmental and Rural Development 5 ( 1 ) 53 - 57 2014年04月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
ホンジュラス国最大の湖沼を対象に，エリ蚕とエコブロックを活用した水質浄化技術の確立について論じた内容である。
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Evaluation of Tide Embankment and Protection Forest Width on Tsunami Disaster Using Tsunami Simulator "jointly worked" 査読あり
Youki MAEDA, Hiromu OKAZAWA, Yasushi TAKEUCHI, Tomonori FUJIKAWA
International Journal of Environmental and Rural Development 4 ( 1 ) 104 - 108 2013年10月
担当区分：責任著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
福島県南相馬市の沿岸では，東日本大震災による津波によって農地が堆砂によって甚大な被害を受けた。本研究では室内の実験用開水路において津波を再現し，防潮堤と防潮林による堆砂抑制効果を実験レベルで実証した内容である。
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クリンカアッシュの粒径組成が窒素吸着効果に及ぼす影響（共著） 査読あり
山本 仁，岡澤 宏，竹内 康，村上由貴
農業農村工学会論文集 285 19 - 24 2013年06月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
クリンカアッシュは多孔質な物質であるため，水質浄化が期待できる廃棄物である。廃棄物の再利用の注目し，本研究では窒素汚濁された農業排水を対象に，クリンカアッシュによる水質浄化機能について，吸着効果に着目をして検討をした。そして，3ヶ月にわたるカラム試験の結果から，クリンカアッシュによる窒素吸着特性について明らかにした。
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Water Quality Preservation Effect of Riparian Forests in Watersheds with Dairy Farming Areas in Eastern Hokkaido "jointly worked" 査読あり
Hiromu OKAZAWA, Tadao YAMAMOTO, Takashi INOUE, Tetuaki NAGASAWA
International Journal of Environmental and Rural Development 4 ( 1 ) 183 - 189 2013年04月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
北海道浜中町には大規模な草地と多数の畜舎が存在しており，いくつかの農業廃水河川がある。河川の周辺には河畔林と呼ばれる林地が集約しており，水質保全機能を有している。本研究では農業由来の窒素により汚濁されている河川水質と河畔林の水質浄化機能との関係を流域レベルで現地データを基に解析した内容である。
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Utilization of Inoculated Eri Cocoon for Water Pollutant Removal "jointly worked" 査読あり
CARLOS ONAN MENDOZA TOVAR, KUMIKO KAWABE, HIROMU OKAZAWA, MACHITO MIHARA
International Journal of Environmental and Rural Development 4 ( 1 ) 164 - 168 2013年04月
記述言語：英語 掲載種別：研究論文（学術雑誌）
ホンジュラス国に位置するヨホア湖の水質保全を目的とし，未利用資源で有りエリ蚕を活用して水質保全技術の開発と適用性について述べた論文である。
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Input of Pollutants by Water Sources of Lake Yojoa, Honduras "jointly worked" 査読あり
Carlos Onan Mendoza Tovar, Hiromu Okazawa, Machito Mihara
International Journal of Environment and Rural Development 3 ( 1 ) 131 - 136 2012年12月
記述言語：英語 掲載種別：研究論文（学術雑誌）
ホンジュラスのYojoa湖を対象に，湖に流入する水の流域を3つに分けて各流域が湖の水質汚濁に及ぼす影響を統計的に検討した内容である。
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The Nitrate Nitrogen Concentration in River Water and the Proportion of Cropland in the Tokachi River Watershed "jointly worked" 査読あり
Toshimi Muneoka, Hiromu Okazawa, Osamu Tsuji, Masato Kimura
International Journal of Environment and Rural Development 3 ( 2 ) 193 - 199 2012年10月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
北海道十勝川において広域的に実施した水質調査から，土地利用と河川窒素濃度との関係を検討した内容である。
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Water Quality Improvement by Natural Meandering River Surrounded by Woods in Agricultural Watersheds "jointly worked" 査読あり
Hiromu Okazawa, Tadao Yamamoto, Takashi Inoue, Tetuaki Nagasawa
International Journal of Environment and Rural Development 3 ( 1 ) 137 - 143 2012年04月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
北海道十勝平野を流れる複数河川において，自然河川区間を対象に窒素浄化機能を定量的に評価した内容である。
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Study on Evaluating the Hardness of the Sidewalk Pavement "jointly worked" 査読あり
MIE HIGUCHI, YASUSHI TAKEUCHI, HIROMU OKAZAWA, KEN-ICHI SATO
International Journal of Environmental and Rural Developnent 2 ( 1 ) 77 - 82 2011年12月
記述言語：英語 掲載種別：研究論文（学術雑誌）
歩行系舗装の弾力性について，簡易試験法であるSB/GB試験の結果と小型FWDによる弾性係数との関係性から評価した内容である。
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Effect of Land Use Agglomeration on Nitrogen Concentration in River Water in the Tokachi River "jointly worked" 査読あり
HIROMU OKAZAWA, TOSHIMI MUNEOKA, YUDAI KUDO, YASUSHI TAKEUCHI
International Journal of Environmental and Rural Development 2 ( 1 ) 37 - 42 2011年12月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
十勝川流域を対象に，土地利用の集塊性が河川の窒素濃度に及ぼす影響を数値的に評価した内容である。
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Fundamental Study on Nitrogen Removal from Paddy Drainage Using Clinker Ash "jointly worked" 査読あり
HITOSHI YAMAMOTO, HIROMU OKAZAWA, YUKO OHTAKA, YASUSHI TAKEUCHI, YOSHITAKA MURAKAMI
International Journal of Environmental and Rural Development 2 ( 1 ) 54 - 58 2011年12月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
水田から排出される窒素成分を対象に，クリンカアッシュによる水質浄化能について検討した。
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信頼性を考慮した路床弾性係数の簡易算出式の提案（共著） 査読あり
竹内 康，毛 世華，岡澤 宏，木幡行宏，西澤辰男
土木学会論文集E1（舗装工学），舗装工学論文集 67 ( 3 ) 95 - 101 2011年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌）
アスファルト舗装の理論tけいせっけいほうにおいて，路床の弾性係数はShellの設計法に記載されている簡易式が用いられることが多い。本報告では，国内において実施された研究成果から，この簡易式の信頼性について検討した論文である。
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コンクリート舗装における路盤厚設計曲線の信頼性に関する検討（共著） 査読あり
竹内 康，毛 世華，岡澤 宏，小梁川雅，西澤辰男，堀内智司
土木学会論文集E1（舗装工学） 67 ( 2 ) 111 - 119 2011年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌）
土木研究所において実大コンクリート舗装で計測したデータを基に，従来から路盤厚の設計に用いられてきた設計曲線の信頼性を検討した論文である。
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Physical and Chemical Properties of Tsunami Deposits in the Northeast Area of Fukushima Prefecture after the Tohoku-Kanto Earthquake "jointly worked" 査読あり
Fujikawa, T., Okazawa, H., Nakamura, T., Takeuchi, Y., and Komamura, M.
International Journal of GEOMATE 1 ( 1 ) 44 - 49 2011年10月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
2011年3月11日に発生した東北沖地震で被災した福島県南相馬市において，津波によって水田に堆積した堆積物と水田土壌の理化学性について述べた論文である。
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STUDY ON DESIGN OF BASE COURSE THICKNESS FOR CONCRETE PAVEMENT "jointly worked" 査読あり
MAO Shihua, Yasushi TAKEUCHI, Hiromu OKAZAWA, Tatsuo NISIZAWA, Satoshi HORIUCHI
PROCEEDINGS, 6th WORKSHOP ON PAVEMENT TECHNOLOGIES 13 - 21 2011年09月
記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス）
コンクリート路盤の設計に関して，層厚と弾性係数との関係が一般的に知られている。この関係について，現場データを使用して信頼性を評価した論文である。
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混住化地域における農家と非農家との生活環境意識の相違（共著） 査読あり
左村 公，岡澤 宏，中村好夫男
農村計画学会誌 30 ( 2 ) 172 - 178 2011年09月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
神奈川県開成町を対象に，アンケート調査を実施し，農家と非農家がこの地域において感じている住環境の相違を数学的に解析し，明らかにした論文である。
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ハイブリッド型ロードヒーティングシステム装置の開発とロードヒーティングへの適用性に関する研究（共著） 査読あり
村上由貴，竹内 康，岡澤 宏，小梁川雅，牧 恒雄
東京農大農学集報 56 ( 1 ) 50 - 59 2011年04月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（大学，研究機関等紀要）
積雪寒冷地のロードヒーティングシステムを新たに考案し，室内実験を通じてその性能について明らかにした論文である。
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農学系学生のための専門科目「水理学」の教育指導に関する研究（共著） 査読あり
細川吉晴，竹下伸一，長坂貞郎，岡澤 宏，小島信彦，嶋 栄吉
宮崎大学農学部研究報告 57 23 - 37 2011年02月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
農学系の専門科目である水理学について，宮崎大学と私立大学4校の実態と問題点を把握するとともに，効果的な教育方法について論じた内容である。
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Influences of Riparian Land Use on Nitrogen Concentration of River Water in Agricultural and Forest Watersheds of Northeastern Hokkaido, Japan "jointly worked" 査読あり
Hiromu Okazawa, Daiji Yamamoto and Yasushi Takeuchi
International Journal of Environmental and Rural Development 1 ( 2 ) 1 - 6 2010年
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
北海道東部の斜網地域において36流域を対象に河川の水質調査を行った。水質調査とGISによる土地利用解析により，河川の窒素濃度と畑草地率，河畔緩衝帯との関係を明らかにし，河川の窒素濃度を低下させるための土地利用について言及した。
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土質材料の違いを考慮した路床の永久変形解析に関する研究（共著） 査読あり
竹内 康，小田喜隆二，毛 世華，岡澤 宏
土木学会舗装工学論文集 14 1 - 8 2009年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌）
種類の異なる土質材料を用いた繰り返し三軸圧縮試験結果から，土質材料の違いを考慮した簡易な永久変形法について検討を行った．
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Fundamental Study on Bearing Capacity Evaluation of Base Course for Concrete Pavement "jointly worked" 査読あり
MAO S., TAKEUCHI Y., OKAZAWA H., KOYANAGAWA M., NISHIZAWA T., INOUE T. and YOSHIMOTO T.
CJWPT 2009, Proceedings of 5th China-Japan Workshop on Pavement Technologies 133 - 138 2009年09月
記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス）
コンクリート舗装を行った実験区間において歪み等を計測した結果から弾性係数の逆解析を実施し，コンクリート舗装の支持力を評価した基礎的研究である．
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Long-term-discharge Analysis Using the EPA Method for the Tana River in Kenya "jointly worked" 査読あり
Hiromu OKAZAWA, Hiromichi TOYODA, Shinji SUZUKI, Sawahiko SHIMADA and Ryuzo NISHIMAKI
沙漠研究 19 ( 1 ) 257 - 260 2009年06月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（学術雑誌）
ケニア国最大の河川であるTANA Riverにおいて長期的に観測された流量データと降雨データをもとに，EPA法を用いて水文データの長期トレンド解析を実施した．その結果，TANA Riverの流量は近年増加傾向にあり，降雨パターンも変動傾向にあることが示された．
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Relationship between Vegetation and Topography for an Erosion Management in Ethiopia "jointly worked" 査読あり
Anissa GARA, Sawahiko Shimada, Hiromu OKAZAWA, Shinji SUZUKI and Ahmed GHRABI
沙漠研究 19 ( 1 ) 257 - 260 2009年06月
記述言語：英語 掲載種別：研究論文（学術雑誌）
エチオピアを対象に，DEMと土地利用データを用いてGISにより地形，土地利用と土壌浸食との関係を検討した論文である．
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北海道斜網地域における土地利用の集塊性と河川の硝酸態窒素濃度の関係（共著） 査読あり
岡澤 宏，竹内 康，左村 公
農業農村工学会論文集 259 53 - 59 2009年02月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
北海道斜網地域の農業流域河川を対象に水質水文調査を実施し，土地利用と河川窒素濃度との関係を検討した．その結果，河川窒素と畑草地面積率との間に高い相関があることが改めて確認された．また，森林・畑草地の集塊性が河川窒素濃度と相関があることが明らかになった．
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軟質FRPライニング工法による開水路の粗度係数（共著） 査読あり
岡澤 宏，竹内 康，増野途斗，牧 恆雄
東京農業大学農学集報 53 ( 3 ) 194 - 199 2008年12月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（大学，研究機関等紀要）
軟質FRPライニング工法を施した補修板を対象に，老朽化水路に施工した場合の通水性の改善効果について明らかにした．通水性の指標にはManning公式の粗度係数を使用し，導水勾配と流量の指標であるRe数との関係を明らかにした．
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小規模・高齢化集落活性化への農業農村工学的アプローチ（共著） 査読あり
高橋 悟，鈴木伸治，岡澤 宏，渡邉文雄
水土の知 12 ( 76 ) 15 - 18 2008年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌）
島根県大田市西田地区を対象に，特異な文化遺産であるヨズクハデの発生起源について農業農村工学的にアプローチした論文である．
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網走川水系における農業的土地利用と河川の窒素・リン濃度の関係（共著） 査読あり
岡澤 宏，豊田裕道，島田沢彦，鈴木伸治，竹内 康
農業農村工学会論文集 258 45 - 50 2008年12月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
北海道網走川水系において支流河川の水質水文調査を実施し，河川の窒素・リン濃度と支流域の畑草地率との関係を検討した．そして，支流河川のN/P比は畑草地率と密接な関係があり，網走湖の富栄養化に影響を及ぼしていることを明らかにした．
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田村堀の開発と番水制の成立要因（共著） 査読あり
増野途斗，岡澤 宏，中村好男
水土の知 76 ( 7 ) 31 - 35 2008年07月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
田村堀は相模川の右岸川支流である小鮎川から取水して4ヵ村を灌漑していた農業用用排水路である.本研究では，田村堀の灌漑方式である番水制の開発に関する経緯と成立要因について検討した．
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積雪寒冷地におけるアスファルト舗装の熱伝導解析に関する基礎的研究（共著） 査読あり
竹内 康，岡澤 宏，江向俊文，馬場竜介，牧恒 雄
農業土木学会論文集 245 95 - 100 2006年10月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
本研究では，積雪寒，冷地における効率的なロードヒーティングシステムを構築するための基礎データ収集を目的として、新潟県妙高市立姫川原小学校の校庭にウェザーステーションを設置し，校庭内に敷設されている簡易アスファルト舗装体内の積雪前後の温度変化を測定した．そして，この測定データを用いて一次元非定常熱伝導解析を実施したところ，舗装周辺からの水分浸透による地盤の温度拡散率の変化が地盤内の時系列温度変化に影響を及ぼしており，簡易アスファルト舗装において温度分布を推定するためには地盤内の水分変化を把握する必要があることがわかった．
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農村地域における水田を利用した震災時の避難労力低減効果（共著） 査読あり
左村公，岡澤 宏，島田沢彦，中村好男
農業土木学会論文集 242 115 - 122 2006年04月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
水田と宅地が混住化する水田地域を対象に，震災時に水田を避難経路として活用する場合，地域住民の避難活動に及ぼす水田の効果を検証した．
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北海道南西部の草地畜産流域における河川水文と汚濁負荷流出特性（共著） 査読あり
岡澤 宏，長澤徹明，井上京，山本忠男
農業土木学会論文集 240 63 - 70 2005年12月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
森林流域と農業流域における平水時，降雨流出時，融雪流出時の河川水質汚濁について扱った研究であり，流域からの窒素負荷流出は降雨流出時と融雪流出時に大半が流出することを定量的に示し，河川流出時の水質保全の重要性を示した．
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森林流域と農業流域における融雪流出時の汚濁負荷流出特性（共著） 査読あり
岡澤 宏，長澤徹明，井上京，山本忠男
農業土木学会論文集 237 57 - 65 2005年06月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
北海道南西部の森林流域と農業流域において，融雪期間を通じて河川の水質水文状況を観測した．農業流域では森林流域の1.7倍に相当するT-N比負荷が流出している実態を明らかにした．また，融雪流出に伴う流出負荷は，大部分が融雪盛期の短期間に流出することを示した．
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小雪寒冷な酪農流域における融雪融凍期の水質水文環境（共著） 査読あり
鵜木啓二，山本忠男，井上京，長澤徹明，岡澤 宏
農業土木学会論文集 228 9 - 15 2003年12月
記述言語：日本語 掲載種別：研究論文（学術雑誌）
融雪融凍期における農業流域河川の汚濁物質流出状況を明らかにし，水質保全対策について検討した．小雪寒冷地域の北海道東部大規模酪農流域において，ケイ酸を指標とした流出分離の結果，流量増加時には9割以上が表面流出であった．また，家畜糞尿由来の物質が高濃度で流出していた．地表面が凍結している場合，草地に散布されていた堆肥や畜産施設等の負荷限から流出した物質に対し，土壌による濾過・捕捉機能がほとんど発揮されないためと推察した．
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北海道東部の畑作地帯における降雨流出時の河川水質特性（共著） 査読あり
岡澤 宏，井上京，山本忠男，長澤徹明，鵜木啓二
農業土木学会論文集 227 33 - 40 2003年10月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
北海道東部の畑作地帯において降雨流出時の河川水質変動を把握し，汚濁負荷流出特性を検討した．河川流量の80％が基底流出によって形成されており，リンとSS成分は直接流出，T-N，硝酸態窒素は基底流出と高い相関を示した．直接流出，基底流出とT-N負荷の関係から，重回帰分析によって各流出のT-N濃度を推定し，負荷分離を行った．T-N負荷の75％が基底流出であり，その大部分が硝酸態窒素によって構成されていることが明らかになった．
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Effect of Previous Flood on Suspended Sediment Transport during Rainstorm Runoff "jointly worked" 査読あり
OKAZAWA Hiromu, NAGASAWA Tetuaki，INOUE Takashi，YAMAMOTO Tadao
Proceedings 12th International Soil Conservation Conference, Process of Soil Erosion and Its Environment Effect ( II ) 26 - 31 2002年05月
担当区分：筆頭著者 記述言語：英語 掲載種別：研究論文（国際会議プロシーディングス）
北海道南西部の森林流域と農業流域における浮流土砂流送挙動の比較を通じて，降雨流出時の浮流土砂流送を河川流量と流出履歴に着目して検討した．両流域の浮流土砂流送機構を降雨流出規模と河川流出履歴に着目して考察したところ，農業流域では河川の流出規模と流出履歴によって，浮流土砂濃度を説明することができた．
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Changes in Erodibility and Eutrophic Components Outflow due to Armoring of Bottom Sediments "jointly worked" 査読あり
MIHARA Machito，OKAZAWA Hiromu
農業土木学会論文集 214 105 - 110 2001年08月
記述言語：英語 掲載種別：研究論文（学術雑誌）
底質の粗粒下に伴う受食性の変化をコンシステンシーの変化とともに検討した．また，粗粒下に伴う底質からの富栄養化成分の流出特性についても検討した．供試体表面の水分状態が液性限界を上回って，塑性領域から液性領域へと変化すると侵食量が増大した．また，侵食に伴って富栄養化成分も流出することが明らかになった．
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北海道南西部の農林地流域における降雨時の河川水質環境（共著）
岡澤 宏，長澤徹明，井上京，山本忠男
農業土木学会論文集，農業土木学会 211 35 - 42 2001年02月
担当区分：筆頭著者 記述言語：日本語 掲載種別：研究論文（学術雑誌）
北海道南西部の農林地流域を対象として降雨流出時における河川の水質水文状況を観測し，流域水文環境と水質特性との関係を検討した．流域の水分状態を表す指標として「流域貯水量：IS」を定義し，河川窒素濃度との関係を検討した結果，両者の間には有意な関係が認められた．そして，農業流域では降雨直前におけるISによって，降雨流出時の河川窒素濃度は影響を受けることを明らかにした．
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Erosion Mechanism of Bottom Muds and Eutrophic Components Outflow "jointly worked"
MIHARA Machito，OKAZAWA Hiromu
農業土木学会論文集，農業土木学会 194 33 - 40 1998年04月
記述言語：英語 掲載種別：研究論文（学術雑誌）
同心軸回転侵食装置を用いて，排水河川底泥の侵食特性とそれに伴う窒素，リン成分の流出について検討した．その結果，底泥表層のレオロジー的性質によって河川底泥の侵食特性が異なることを明らかにした．また，底泥の侵食にともなって窒素・リンも流出することが明らかになった．