京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第22052号 / 工博第4633号 / 新制||工||1722(附属図書館) / 京都大学大学院工学研究科都市社会工学専攻 / (主査)教授 角 哲也, 准教授 Sameh Kantoush, 准教授 竹門 康弘 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

This study was aimed to assess the status of waste treatment for cow raising at small farm households in Can Tho, Tra Vinh, Soc Trang, and Hau Giang. The interview of 120 cow farmer households indicated that local farmers normally treat their waste by sun-drying, storing in ponds, discharging directly into rivers, or applying to anaerobic biogas. The farmers select ways to treat cow excrement according to seasons of the year: in the dry season cow waste is mostly sun-dried for sale (76.7%); stored for use (10%), untreated (7.5%) or applied to biogas plants (5.8%); however, in the rainy season most of the farmers leave the waste untreated (94.2%), except for those owning biogas tanks. Biogas treatment is applied mainly by dairy cow-raising households, accounting for 85.7% of biogas users. The cow farmer households have limited knowledge about biogas application; 23.3% of the interviewed farmers knew about biogas technology; 47.5% had little knowledge about this technology, however, 29.2% of the selected persons had no idea about biogas technology. Based on the quantity of beef cattle herds in the surveyed areas, it is estimated that CH4 gas emissions account for around 252.3 tons, 61.4 tons, 8.2 tons, and 2.5 tons in Soc Trang, Tra Vinh, Can Tho, and Hau Giang, respectively. / Nghiên cứu này nhằm đánh giá hiện trạng xử lý chất thải tại các hộ chăn nuôi bò ở thành phố Cần Thơ và các tỉnh Trà Vinh, Sóc Trăng, Hậu Giang. Tổng số 120 hộ chăn nuôi đã được phỏng vấn cho thấy có 4 phương pháp xử lý chính để xử lý chất thải chăn nuôi phát sinh: ủ yếm khí (biogas), phơi khô và bán, trữ lại trong ao để sử dụng, và không xử lý. Tùy theo thời điểm trong năm người dân sẽ thay đổi cách thức xử lý chất thải chăn nuôi bò: vào mùa khô có nhiều nắng chủ yếu người dân phơi khô để bán (76,7%), để lại và sử dụng (10%), dùng để ủ biogas (5,8%), và không xử lý (7,5%); tuy nhiên vào mùa mưa hầu hết các hộ dân không xử lý chất thải chăn nuôi (94,2%), chỉ trừ những hộ dân đã có hầm ủ biogas để xử lý. Xử lý chất thải chăn nuôi bằng công nghệ biogas được áp dụng phổ biến ở các hộ nuôi bò sữa, chiếm 85,7% số hộ có hầm ủ biogas. Sự hiểu biết về công nghệ biogas của các hộ chăn nuôi còn khá giới hạn, chỉ 23,3% hộ dân được phỏng vấn biết về công nghệ biogas, 47,5% hộ biết ít về công nghệ này, trong khi 29,2% hộ dân hoàn toàn không biết. Dựa trên số lượng đàn bò thịt trong vùng khảo sát, có thể tính được lượng CH4 phát thải hàng năm từ chất thải chăn nuôi là 252,3 tấn, 61,4 tấn, 8,2 tấn và 2,5 tấn từ các địa phương Sóc Trăng, Trà Vinh, Cần Thơ, và Hậu Giang.

This study focuses on the design of water resources systems in developing nations with particular reference to the development of water resources in the Lower Mekong Basin (Khmer Republic, Laos, Thailand, and Republic of South Viet-Nam). The determination of the "best" system in terms of social goals reflecting the economic and social environment of the Mekong countries is the main issue of this dissertation. The imperfection of the usual technique for planning water resources systems, namely, cost-benefit analysis, leads to the use of the standardized cost-effectiveness methodology. To illustrate how the design is accomplished, two distinctly different structural alternatives of possible development in the Lower Mekong Basin are defined. The design process starts from the statements of goals or objectives of water resources development, which are then mapped onto specifications sets in which social needs are represented. Next, the capabilities of alternative systems are determined through simulation in which three 50-year sequences of synthetic streamflow are generated by a first order autoregressive scheme. The two alternatives are then compared using both quantitative and qualitative criteria. To illustrate how a decision in selecting an alternative system could be reached, ranking of criteria by order of preference is demonstrated. With the choice of either a fixed-cost or fixed-effectiveness approach, the decision to select the best alternative system could be made. At this point, the use of a weighting technique, which is a common fallacy of systems analysis, will be automatically eliminated. The study emphasizes that a systematic design procedure of water resources systems is provided by the standardized cost-effectiveness approach, which possesses several advantages. The approach will suggest and help identify the system closest to meeting the desired economic and social goals of the developing countries in the Lower Mekong Basin. In this connection, the approach will help governments in the preparation of programming and budgeting of capital for further investigations and investments. It is believed that the approach will eliminate unnecessary expenses in projects that are planned on an individual basis or by methods used at present. Further, the approach provides an appropriate mechanism for generating essential information in the decision process. Both quantifiable and non-quantifiable criteria are fully considered. The choice of a fixed-cost or fixed-effectiveness approach will determine the trade-off between these criteria. The study recognizes that research to determine appropriate hydrologic models for monthly streamflow generation for tributary projects in the Basin is necessary. This leads to another important area of research which is to find the appropriate number of monthly sequences of streamflow to be generated in relation to number of states and decision variables. Research on the design of computer experiments is necessary to improve simulation as a tool to estimate the quantitative effects of a given project.

Soil degradation is a complex process which may occur anywhere and at any time. It directly affects the physical, chemical and biological processes within the soil profile. Soil degradation can either be as a result of natural hazards or due to manmade actions, such as mismanagement on cropping patterns, soil preparation and cultivation practices. Regardless of how it is caused, soil degradation has strong negative effects on plant and soil productivity. Soil degradation can accelerate a series of processes such as erosion, compaction, loss of organic matter, loss of whole soil biota, surface sealing and contamination. This thesis presents the assessment of soil properties to improve our understanding of soil degradation on raised-bed orchards in the Vietnamese Mekong delta (MD). Measurements were made on 10 citrus plantations which had been established during a range of years from 1970 to 1998 at Hau Giang province. Soil sampling was made in the dry season of 2010 at two soil depths for each raised-bed to determine soil chemical and physical properties. The soil penetration resistance (PR) was periodically measured once a week together with soil sampling for moisture measurements during a period of 5 months. Analysis indicated the pH value of the soil was tending to decrease, nutrient imbalance and deficiency was developing, and the soil structure was deteriorating during the age since the raised-beds were originally constructed. Preventive and restorative measures need to be considered for restoring and retaining the quality of the soil and the ground water. These measures should consist of (1) neutralizing of excess acidity, (2) balancing of nutrients, (3) maintaining of soil organic matter, and (4) application of appropriate irrigation schedules. / Suy thoái đất là một tiến trình phức tạp xuất hiện ở mọi nơi, mọi lúc làm tác động trực tiếpđến các quá trình lý, hóa và sinh học trong phẫu diện đất. Nó có thể là kết quả của các hoạtđộng do tự nhiên hoặc do con người như sử dụng sai hoặc thực hành quản lý đất đai bất hợplý. Cho dù nguyên nhân thế nào chăng nữa, suy thoái đất cũng gây ra các ảnh hưởng bất lợinặng nề lên cây trồng và sức sản suất của đất. Suy thoái đất có thể thúc đẩy hàng loạt cácquá trình như là xói mòn, nén dẽ, mất vật liệu hữu cơ và sinh vật đất, đóng váng bề mặt vàô nhiễm. Luận văn này trình bày sự đánh giá về các đặc tính của đất để mở mang sự hiểubiết về suy thoái đất trên các vườn cây ăn trái ở đồng bằng sông Cửu Long. Thí nghiệmthực hiện trên 10 vườn cam quít với khoảng thời gian thành lập vườn từ 1970 đến 1998 tạitỉnh Hậu Giang. Mẫu đất được lấy vào mùa khô năm 2010 ở hai độ sâu cho mỗi vườn đểphân tích các chỉ tiêu lý hóa đất. Sức kháng xuyên của đất được đo định kỳ mỗi tuần kếthợp với lấy mẫu để xác định ẩm độ đất trong suốt khoảng thời gian 5 tháng. Kết quả phântích cho thấy pH đất có khuynh hướng giảm, sự thiếu và mất cân bằng dinh dưỡng đất ngàycàng lộ rõ, và cấu trúc đất đang xấu đi theo độ tuổi của vườn. Các biện pháp phòng ngừa vàphục hồi cần được quan tâm đối với việc phục hồi và duy trì chất lượng của đất và nướcngầm. Các biện pháp nên bao gồm (1) trung hòa độ chua đất, (2) cân bằng dinh dưỡng, (3)duy trì vật liệu hữu cơ trong đất, và (4) áp dụng chế độ tưới thích hợp. / <p>QC 20130909</p>

The intensification of agricultural production in the Mekong Delta has faced serious challenges with respect to increased use of agrochemicals and especially pesticides. The indiscriminate use of pesticide could potentially impact on the long-term food production, environmental and human health in the delta. The aim of this thesis was to investigate the negative side effects of the current use of pesticides on climbing perch (Anabas testudineus) in rice fields using brain acetylcholinesterase (hereafter referred to as AChE) activity as a biomarker. The empirical work, on which this thesis is based, includes structured questionnaires, laboratory and field experiments. First, a field survey using questionnaires was carried out to gain a better understanding of the current state of rice farming systems, the use of pesticides and attitude to pest management strategies among rice and rice-fish farmers, as well as to provide basic information for the set-up of the laboratory and field experiments. Secondly, laboratory studies were conducted to clarify if the selected insecticides applied alone and in mixtures caused negative side effects on climbing perch fingerlings. Thirdly, further toxicity studies were carried out, under rice field conditions, to further investigate the toxicity effects of the insecticides, applied alone, in mixtures and under sequential applications, on climbing perch fingerlings. The results showed that although there were a more selective use of pesticides and an increased awareness among farmers of the negative side effects of pesticides in 2007 as compared to 1999, the current use of pesticide in the Mekong Delta still cause many problems to the environment and human health. Chlorpyrifos ethyl (hereafter referred to as CPF) was found to cause a significant and more prolonged inhibition on the brain AChE activity in climbing perch than fenobucarb (hereafter referred to as F). The inhibition by the mixture of CPF and F were significantly higher than the inhibition by only F, but less prolonged and significant lower than the inhibition by only CPF. The results suggest that the combined effect from a mixture of F and CPF can create both additive effects initially and later antagonistic effects. CPF and F applied at concentrations used by farmers, either as separate doses, in a mixture or in sequential doses, decreased the brain AChE activity, growth and survival rates in climbing perch. The results demonstrate that brain AChE activity in climbing perch is a relevant biomarker for monitoring of exposure to, and sub-lethal impacts from organophosphates and carbamates under tropical conditions. The result also shows that 2-PAM re-activate the brain AChE activity, and can be used as an alternative method to assess the AChE inhibition level in organisms recently exposed to OP’s, in situation where it may be difficult to find unexposed individuals as controls. In conclusion, this thesis shows that the current use of pesticides in the Mekong Delta has a negative effect on climbing perch living in rice fields. It indicates that a sustained long-term food production in the Mekong Delta must be based on ecological principles, taking advantages of ecosystem biodiversity and productivity, and not through intensified use of pesticides. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Submitted. Paper 5: Submitted.</p>

No description available.

Landfilling is the most common treatment of Municipal Solid Waste (MSW) in the An Giang province in south Vietnam. Many of the landfills are not sanitary and can be harmful to the environment and the residents, especially those who live within the settled distance limit of 1000 meters. There is a lack of knowledge about the people living close to landfills in the An Giang province. Therefore, the aim of the study was to investigate any issues about living close to landfills, by comparing health, knowledge and social issues, between people living near landfills and people in urban areas in the An Giang province. A total of 80 people was chosen in Long Xuyen and An Phu, for a questionnaire. The data was compiled and coded in Excel for further analyzation in SPSS. The results show differences in social issues, health and knowledge related to landfilling and solid waste. The experiences in the landfill areas could be taken in advantage. The study suggests using students in communication programs and workshops to increase knowledge and practice about solid waste among the citizens. To monitor landfills and the air in due to open burning of solid waste, is recommended. / Deponering är den vanligaste behandlingen av hushållsavfall i An Giang-provinsen i södra Vietnam. Många av dessa soptippar (deponier) är inte sanitära och kan vara skadliga för både miljön och invånarna som bor inom den bestämda avståndsgränsen på 1000 meter. Det finns brist på kunskap om de människor som bor nära deponier i An Giang-provinsen. Därför var syftet med studien att undersöka förekomsten av problem av att bo nära deponier i provinsen. Detta gjordes genom att jämföra hälsa, kunskap och sociala frågor mellan människor som bor intill deponier och människor i urbana områden. Totalt valdes 80 personer i Long Xuyen och An Phu till en enkätstudie. Uppgifterna sammanställdes och kodades i Excel för vidare analys i SPSS. Resultaten visade skillnader i sociala frågor, hälsa och kunskap relaterade till deponering och fast avfall. I deponiområdena fanns det mycket erfarenhet som skulle kunna utnyttjas. Studien föreslår bl.a. att använda skolungdomar i kommunikationskampanjer och workshops för att öka kunskap och praxis hos invånarna. Att övervakning och mäta deponier och luften p.g.a. öppen eldning av avfall, rekommenderas.

This study details the effects of climate change and market fluctuations on the rural district of Cu Lao Dung located in the Mekong Delta of southern Vietnam. Using theoretical concepts on modernity, the environment and water from researchers Arjun Appadurai, Tim Ingold and Veronica Strang I study the political ecology of the Delta. Through interviews with farmers I found that climate change and market fluctuations are stalling economic development and significantly worsening already strong migration flows, leading to many people of working age leaving the district. Insufficient government support and dire climate projections means that the problems observed on Cu Lao Dung are only posed to grow worse.

The Mekong Delta, which is considered as the main 'rice bowl and fish basket', is one of seven distinct agro-ecological regions of Vietnam and plays an important role in the economy of the country. Several rice-based farming systems have been developed in various areas of the MD. Rice-shrimp integrated system in brackish areas is a special farming system developed in this delta. It is a profitable system and seems to be environmentally safe on the one hand without the use of pesticides. On the other hand, use of brackish water in this system may result in degradation of land, as some previous studies have found. To understand how this farming system works and to identify the external and internal factors influencing its sustainability, the project 'Sustainability of rice-shrimp farming system in a brackish area in the Mekong delta of Vietnam' was carried out in 1992-1993 by an interdisciplinary team of researchers from the University of Cantho and staff of local district Agricultural Office, representing different fields of sciences. The research methodology was the Farming Systems Research approach with modifications towards soft systems thinking, involving farmers into the research process. One main result of this study is an insight into the rice-shrimp farming system. It includes various physical, biological, technological, economical and sociological aspects of rice production prior to integration and in integrated farm, naturally supplied shrimp growing and giant shrimp rearing, upland crop production as well as off-farm and non-farm work of farm households. Sustainability of the system studied is assessed, in comparison with rice monoculture, through various criteria of the three view points productivity, environmental safety and socio-economic effectiveness. In terms of such points of view, rice-shrimp farming system is rated higher than rice monoculture system. Thus the integrated system so far is considered to be more sustainable than the others. / Master of Science (Hons)

Master of Science / The objective of this research is to employ Geographical Information Systems to fisheries management in the Mekong River Basin. The study uses artisanal fisheries practices in Khong district, Champasack province Lao PDR as a case study. The research focuses on integrating indigenous and scientific knowledge in fisheries management; how local communities use indigenous knowledge to access and manage their fish conservation zones; and the contribution of scientific knowledge to fishery co-management practices at village level. Specific attention is paid to how GIS can aid the integration of these two knowledge systems into a sustainable management system for fisheries resources. Fieldwork was conducted in three villages in the Khong district, Champasack province and Catch per Unit of Effort / hydro-acoustic data collected by the Living Aquatic Resources Research Centre was used to analyse and look at the differences and/or similarities between indigenous and scientific knowledge which can supplement each other and be used for small scale fisheries management. The results show that GIS has the potential not only for data storage and visualisation, but also as a tool to combine scientific and indigenous knowledge in digital maps. Integrating indigenous knowledge into a GIS framework can strengthen indigenous nowledge, from un processed data to information that scientists and decision-makers can easily access and use as a supplement to scientific knowledge in aquatic resource decision-making and planning across different levels. The results show that when scientific and indigenous knowledge are both stored digitally in GIS databases, a variety of analysis can be done. Multiple layers or visualising functions in ArcGIS are an example of ways in which indigenous and scientific knowledge can be combined in GIS. Maps of deep pools and important fishing grounds gathered using GPS and indigenous knowledge provide base maps of aquatic resources in the study area. The attribute table associated with the map links characteristics of each point, including fishing gear and species found in each pool as well as spawning grounds and migration periods. This information is useful for management and planning purposes. This research illustrates that mental maps and GIS digital maps can be used for fisheries management at different levels. Where mental maps are suitable for communicating with the local community and have the potential for use in fisheries co-management in small-scale fisheries; GIS may be appropriated for data storage and analysis at provincial and national levels, it can be used as a communication tool amongst stakeholders to monitor and understand the aquatic environment.