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Sample records for mekong delta vietnam

  1. Occurrence and Dissipation of the Antibiotics Sulfamethoxazole, Sulfadiazine, Trimethoprim, and Enrofloxacin in the Mekong Delta, Vietnam

    OpenAIRE

    Nguyen Dang Giang, Chau; Sebesvari, Zita; Renaud, Fabrice; Rosendahl, Ingrid; Hoang Minh, Quang; Amelung, Wulf

    2015-01-01

    The Mekong Delta in Vietnam has seen a rapid development and intensification of aquaculture in the last decades, with a corresponding widespread use of antibiotics. This study provides information on current antibiotic use in freshwater aquaculture, as well as on resulting antibiotic concentrations in the aquatic environment of the Mekong Delta. Two major production steps, fish hatcheries and mature fish cultivation, were surveyed (50 fish farm interviews) for antibiotic use. Different water ...

  2. Occurrence and dissipation of the antibiotics sulfamethoxazole, sulfadiazine, trimethoprim, and enrofloxacin in the Mekong Delta, Vietnam

    OpenAIRE

    Das, Surajit; Nguyen Dang Giang, Chau; Sebesvari, Zita; Renaud, Fabrice; Rosendahl, Ingrid; Hoang Minh, Quang; Amelung, Wulf

    2015-01-01

    The Mekong Delta in Vietnam has seen a rapid development and intensification of aquaculture in the last decades, with a corresponding widespread use of antibiotics. This study provides information on current antibiotic use in freshwater aquaculture, as well as on resulting antibiotic concentrations in the aquatic environment of the Mekong Delta. Two major production steps, fish hatcheries and mature fish cultivation, were surveyed (50 fish farm interviews) for antibiotic use. Different water ...

  3. Global and local governance of shrimp farming in the Mekong Delta, Vietnam

    OpenAIRE

    Tran Thi Thu, H.

    2012-01-01

    The Mekong Delta is one of seven ecological regions in Vietnam where aquaculture and shrimp products are internationally traded and the shrimp farmers are firmly embedded in a global system of production and trade. The growth of shrimp aquaculture, in addition to population growth and higher levels of investment, has left coastal resources in the Mekong Delta increasingly vulnerable to rapid changes in land and resource use. The shrimp industry, made up of multiple stakeholders and fragmente...

  4. Sedimentation patterns in floodplains of the Mekong Delta - Vietnam

    Science.gov (United States)

    Van Manh, Nguyen; Merz, Bruno; Viet Dung, Nguyen; Apel, Heiko

    2013-04-01

    Quantification of floodplain sedimentation during the flood season in the Mekong Delta (MD) plays a very important role in the assessment of flood deposits for a sustainable agro-economic development. Recent studies on floodplain sedimentation in the region are restricted to small pilot sites because of the large extend of the Delta, and the complex channel. This research aims at a quantification of the sediment deposition in floodplains of the whole Mekong Delta, and to access the impacts of the upstream basin development on the sedimentation in the Delta quantitatively. To achieve this, a suspended sediment transport model is developed based on the quasi-2D hydrodynamic model of the whole Mekong Delta developed by Dung et al. (2011). The model is calibrated and validated using observed data derived from several sediment measurement campaigns in channel networks and floodplains. Measured sediment data and hydrodynamic model quantify the spatio-temporal variability of sediment depositions in different spatial units: individual dyke compartments, and the sub-regions Plain of Reeds, Long Xuyen Quadrangle and the area between Tien River and Hau River. It is shown that the distribution of sediment deposition over the delta is highly depended on the flood magnitude, that in turn drives the operation policy of flood control systems in floodplains of the Mekong Delta. Thus, the sedimentation distribution is influenced by the protection level of the dyke systems in place and the distance to the Tien River and Hau River, the main branches of the Mekong in the Delta. This corroborates the main findings derived from data analysis obtained from a small scale test site by Hung et al, (2011, 2012a). Moreover, the results obtained here underlines the importance of the main channels for the sediment transport into the floodplains, and the deposition rate in floodplains is strongly driven by the intake locations and the distance from these to the main channels as well.

  5. Contamination of persistent organochlorines in sediments from Mekong River Delta, South Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Hung, Minh Nguyen; Kajiwara, Natsuko; Kunisue, Tatsuya; Subramanian, A.; Iwata, Hisato; Tanabe, Shinsuke [Ehime Univ., Matsuyama (Japan). Center for Marine Environmental Studies; Hung, Viet Pham [Hanoi National Univ., Hanoi (Viet Nam); Cach, Tuyen Bui [Univ. for Agriculture and Forestry, Hochiminh (Viet Nam)

    2004-09-15

    Mekong River is the longest river in southeastern Asia, which flows a distance of almost 4800 km from China through Myanmar, Thailand, Laos, Cambodia and Vietnam. The Mekong River basin with an area of nearly 800 thousand square kilometers is an important habitat for approximately 60 million people. Mekong River delta in South Vietnam, which is inhabited by about 20 million people, is one of the most highly productive agriculture lands in the world. Rice production is major economical sector in Mekong delta contributing half of the rice production in Vietnam - approximately 35 million tons annually. On the other hand, development of agriculture in Mekong delta raised some concern on environmental quality and disturbance on ecosystem. For example, intensive use of organochlorine (OC) insecticides such as DDTs, chlordanes, HCHs may lead to considerable residues in the agriculture land. Moreover, relative persistence of such chemicals together with natural processes like evaporation and run-off, might enhance their ubiquitous distribution in environment, food chains and eventually bio-accumulate in humans. In Vietnam, despite official ban on the usage of OCs on 1995, there have been evidences of recent uses of such chemicals, particularly DDT, throughout the country. It can be anticipated that similar situation may occur in Mekong River delta due to high population density and intensive agriculture activities in this region. Despite this fact, no comprehensive study, to evaluate the status of contamination by persistent OCs in this region, has been made in recent years. In this study, we collected sediments from different locations along Mekong River and determined the concentrations of persistent OCs such as DDTs, HCHs, CHLs, HCB and PCBs in order to elucidate the recent contamination status, their usage pattern as well as to evaluate potential pollution sources of these chemicals to the river.

  6. Livelihood Capabilities and Pathways of Shrimp Farmers in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Tran Thi Phung Ha, Ha; Dijk, van J.W.M.; Bosma, R.H.; Sinh, L.X.

    2013-01-01

    Shrimp farming is a major livelihood activity in the Mekong Delta in the southernmost part of Vietnam. The Vietnamese government has promoted shrimp farming as a way to reduce poverty, provide employment opportunities and increase exports to support economic development. The shrimp farming system,

  7. Global and local governance of shrimp farming in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Tran Thi Thu, H.

    2012-01-01

    The Mekong Delta is one of seven ecological regions in Vietnam where aquaculture and shrimp products are internationally traded and the shrimp farmers are firmly embedded in a global system of production and trade. The growth of shrimp aquaculture, in addition to population growth and higher

  8. Farmers' knowledge, perceptions and practices in mango pest management in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Mele, van P.; Cuc, N.T.T.; Huis, van A.

    2001-01-01

    A survey of mango farmers' knowledge, perceptions and practices in pest management was conducted during the dry season of 1998 in the Mekong Delta, Vietnam. Identification and control of pests was often based on damage symptoms, rather than on recording of causal agents. Damage caused by the

  9. Integrated agriculture-aquaculture systems in the Mekong Delta, Vietnam: an analysis of recent trends

    NARCIS (Netherlands)

    Thanh Phong, Le; Udo, H.M.J.; Mensvoort, van M.E.F.; Bosma, R.H.; Quang Tri, Le; Nhan, D.K.; Zijpp, van der A.J.

    2008-01-01

    In order to explain the trends in the development and farm attributes of Integrated Agriculture-Aquaculture (IAA) systems in the Mekong Delta of Vietnam, a participatory community appraisal and two surveys are carried out in three districts with contrasting fish culture input systems. The first

  10. Dynamic controls on shallow clinoform geometry: Mekong Delta, Vietnam

    Science.gov (United States)

    Eidam, E. F.; Nittrouer, C. A.; Ogston, A. S.; DeMaster, D. J.; Liu, J. P.; Nguyen, T. T.; Nguyen, T. N.

    2017-09-01

    Compound deltas, composed of a subaerial delta plain and subaqueous clinoform, are common termini of large rivers. The transition between clinoform topset and foreset, or subaqueous rollover point, is located at 25-40-m water depth for many large tide-dominated deltas; this depth is controlled by removal of sediment from the topset by waves, currents, and gravity flows. However, the Mekong Delta, which has been classified as a mixed-energy system, has a relatively shallow subaqueous rollover at 4-6-m depth. This study evaluates dynamical measurements and seabed cores collected in Sep 2014 and Mar 2015 to understand processes of sediment transfer across the subaqueous delta, and evaluate possible linkages to geometry. During the southwest rainy monsoon (Sep 2014), high river discharge, landward return flow under the river plume, and regional circulation patterns facilitated limited sediment flux to the topset and foreset, and promoted alongshore flux to the northeast. Net observed sediment fluxes in Sep 2014 were landward, however, consistent with hypotheses about seasonal storage on the topset. During the northeast rainy monsoon, low river discharge and wind-driven currents facilitated intense landward and southwestward fluxes of sediment. In both seasons, bed shear velocities frequently exceeded the 0.01-0.02 m/s threshold of motion for sand, even in the absence of strong wave energy. Most sediment transport occurred at water depths 4 cm/yr at energy-limited, and thus rollover depths cannot be predicted solely by bed-stress distributions. In systems like the subaqueous Mekong Delta, direction of transport may have a key impact on morphology.

  11. A Bio-economic Model of a Shrimp Hatchery in the Mekong River Delta of Vietnam

    OpenAIRE

    Sinh, L.X.; MacAulay, T. Gordon; Brennan, Donna C.

    2003-01-01

    Shrimp culture areas and production of the Mekong Delta cover about 60 percent of the total shrimp areas and production of Vietnam. Especially, the Delta contributes about 80 percent of the total shrimp production for export. Rapid development of the shrimp industry is raising a number of serious problems that need to be solved. Shrimp seed supply (post larvae production) plays an essential role in the shrimp industry and it is one of the most important constraints to the development of the s...

  12. Rise and Fall of one of World's largest deltas; the Mekong delta in Vietnam

    Science.gov (United States)

    Minderhoud, P. S. J.; Eslami Arab, S.; Pham, H. V.; Erkens, G.; van der Vegt, M.; Oude Essink, G.; Stouthamer, E.; Hoekstra, P.

    2017-12-01

    The Mekong delta is the third's largest delta in the world. It is home to almost 20 million people and an important region for the food security in South East Asia. As most deltas, the Mekong delta is the dynamic result of a balance of sediment supply, sea level rise and subsidence, hosting a system of fresh and salt water dynamics. Ongoing urbanization, industrialization and intensification of agricultural practices in the delta, during the past decades, resulted in growing domestic, agricultural and industrial demands, and have led to a dramatic increase of fresh water use. Since the year 2000, the amount of fresh groundwater extracted from the subsurface increased by 500%. This accelerated delta subsidence as the groundwater system compacts, with current sinking rates exceeding global sea level rise up to an order of magnitude. These high sinking rates have greatly altered the sediment budget of the delta and, with over 50% of the Mekong delta surface elevated less than 1 meter above sea level, greatly increase vulnerability to flooding and storm surges and ultimately, permanent inundation. Furthermore, as the increasingly larger extractions rapidly reduce the fresh groundwater reserves, groundwater salinization subsequently increases. On top of that, dry season low-flows by the Mekong river cause record salt water intrusion in the delta's estuarine system, creating major problems for rice irrigation. We present the work of three years research by the Dutch-Vietnamese `Rise and Fall' project on land subsidence and salinization in both groundwater and surface water in the Vietnamese Mekong delta.

  13. Magnitude of arsenic pollution in the Mekong and Red River Deltas - Cambodia and Vietnam

    International Nuclear Information System (INIS)

    Berg, Michael; Stengel, Caroline; Trang, Pham Thi Kim; Hung Viet, Pham; Sampson, Mickey L.; Leng, Moniphea; Samreth, Sopheap; Fredericks, David

    2007-01-01

    Large alluvial deltas of the Mekong River in southern Vietnam and Cambodia and the Red River in northern Vietnam have groundwaters that are exploited for drinking water by private tube-wells, which are of increasing demand since the mid-1990s. This paper presents an overview of groundwater arsenic pollution in the Mekong delta: arsenic concentrations ranged from 1-1610 μg/L in Cambodia (average 217 μg/L) and 1-845 μg/L in southern Vietnam (average 39 μg/L), respectively. It also evaluates the situation in Red River delta where groundwater arsenic concentrations vary from 1-3050 μg/L (average 159 μg/L). In addition to rural areas, the drinking water supply of the city of Hanoi has elevated arsenic concentrations. The sediments of 12-40 m deep cores from the Red River delta contain arsenic levels of 2-33 μg/g (average 7 μg/g, dry weight) and show a remarkable correlation with sediment-bound iron. In all three areas, the groundwater arsenic pollution seem to be of natural origin and caused by reductive dissolution of arsenic-bearing iron phases buried in aquifers. The population at risk of chronic arsenic poisoning is estimated to be 10 million in the Red River delta and 0.5-1 million in the Mekong delta. A subset of hair samples collected in Vietnam and Cambodia from residents drinking groundwater with arsenic levels > 50 μg/L have a significantly higher arsenic content than control groups (< 50 μg/L). Few cases of arsenic related health problems are recognized in the study areas compared to Bangladesh and West Bengal. This difference probably relates to arsenic contaminated tube-well water only being used substantially over the past 7 to 10 years in Vietnam and Cambodia. Because symptoms of chronic arsenic poisoning usually take more than 10 years to develop, the number of future arsenic related ailments in Cambodia and Vietnam is likely to increase. Early mitigation measures should be a high priority

  14. Development of sea level rise scenarios for climate change assessments of the Mekong Delta, Vietnam

    Science.gov (United States)

    Doyle, Thomas W.; Day, Richard H.; Michot, Thomas C.

    2010-01-01

    Rising sea level poses critical ecological and economical consequences for the low-lying megadeltas of the world where dependent populations and agriculture are at risk. The Mekong Delta of Vietnam is one of many deltas that are especially vulnerable because much of the land surface is below mean sea level and because there is a lack of coastal barrier protection. Food security related to rice and shrimp farming in the Mekong Delta is currently under threat from saltwater intrusion, relative sea level rise, and storm surge potential. Understanding the degree of potential change in sea level under climate change is needed to undertake regional assessments of potential impacts and to formulate adaptation strategies. This report provides constructed time series of potential sea level rise scenarios for the Mekong Delta region by incorporating (1) aspects of observed intra- and inter-annual sea level variability from tide records and (2) projected estimates for different rates of regional subsidence and accelerated eustacy through the year 2100 corresponding with the Intergovernmental Panel on Climate Change (IPCC) climate models and emission scenarios.

  15. Production of red tilapia (Oreochromis spp.) in floating cages in the Mekong Delta, Vietnam: mortality and health management.

    Science.gov (United States)

    Boerlage, Annette S; Dung, Tu Thanh; Hoa, Tran Thi; Davidson, Jeffrey; Stryhn, Henrik; Hammell, K Larry

    2017-04-20

    The Mekong Delta in Vietnam is one of the most productive aquaculture regions in the world, in which the red tilapia (Oreochromis spp.) industry is a small-scale industry that mainly supplies local markets in the delta region. Little is known about the frequency of mortality events and health management in this sector. We describe red tilapia floating cage production systems in the Mekong Delta, Vietnam, for the purposes of quantifying mortality and associated production factors, and describing practices that may influence pathogen introduction and spread to and from farms. In July 2014, approximately 50 red tilapia farmers from 4 provinces (201 farmers in total) were randomly selected and interviewed. Median overall perceived mortality (PM) within a production cycle was 35%. Overall PM was found to be affected by province (p tilapia aquaculture management in the Mekong Delta, and describes management factors that could become important in the event of disease outbreaks.

  16. Use of planted biofilters in integrated recirculating aquaculture-hydroponics systems in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Trang, N.T.D.; Brix, Hans

    2014-01-01

    The feasibility of using planted biofilters for purification of recirculated aquaculture water in the Mekong Delta of Vietnam was assessed. The plant trenches were able to clean tilapia aquaculture water and to maintain good water quality in the fish tanks without renewal of the water. NH4-N was ...... rates of 725 kg N and 234 kg P ha-1 year-1. This research demonstrates that integrated recirculating aquaculture-hydroponics (aquaponics) systems provide significant water savings and nutrient recycling as compared with traditional fish ponds....

  17. Influence of pesticide information sources on citrus farmer's knowledge, perception and practices in pest management, Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Mele, van P.; Hai, T.V.; Thas, O.; Huis, van A.

    2002-01-01

    In 1998-99, about 150 citrus farmers and 120 pesticide sellers were interviewed in Can Tho and Dong Thap province, Mekong Delta, Vietnam. Media, pesticide sellers and extension staff had different influences on farmers' pest perception and management practices depending on the region and intensity

  18. The Influence of Changes in the Market Environment on Economic Production Characteristics of Pangasius Farming in the Mekong Delta (Vietnam)

    NARCIS (Netherlands)

    Binh, Van T.; Haese, D' M.F.C.; Speelman, S.; Haese, D' L.

    2010-01-01

    The Mekong Delta in Vietnam has become an important production area for pangasius. The importance of the sector in providing an income to many households means that it is relevant to study its economic production characteristics. In this article we use a stochastic cost frontier model to assess the

  19. The Innovative Structure Solution for Preventing Salt Intrusion and Retaining Freshwater In Mekong Delta VietNam

    NARCIS (Netherlands)

    Hong, S.T.; Vrijling, J.K.; Stive, M.J.F.

    2013-01-01

    In the Mekong Delta Vietnam, the construction of sluices with the purpose of retaining fresh water and preventing salt water intrusion potentially plays a very important role. However, the structures constructed in small rivers according to local or traditional technology revealed many disadvantages

  20. Evaluating farmers' knowledge, perceptions and practices: a case study of pest management by fruit farmers in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Mele, Van P.

    2000-01-01

    After the Doi moi policy reform of Vietnam in 1986, the government has increasingly emphasized diversification of agricultural production into high value crops. Over the period 1985-1995, fruit production in the Mekong Delta increased from 92,100 to 175,700 ha mainly

  1. Microbial Risk Assessment of Tidal−Induced Urban Flooding in Can Tho City (Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    Hong Quan Nguyen

    2017-11-01

    Full Text Available Public health risks from urban flooding are a global concern. Contaminated floodwater may expose residents living in cities as they are in direct contact with the water. However, the recent literature does not provide much information about this issue, especially for developing countries. In this paper, the health risk due to a flood event occurred in Can Tho City (Mekong Delta, Vietnam on 7 October 2013 was investigated. The Quantitative Microbial Risk Assessment method was used in this study. The data showed that the pathogen concentrations were highly variable during the flood event and exceeded water standards for surface water. Per 10,000 people in contact with the floodwater, we found Salmonella caused the highest number of infections to adults and children (137 and 374, respectively, while E. coli caused 4 and 12 cases, per single event, respectively. The results show that further investigations on health risk related to flood issues in Can Tho City are required, especially because of climate change and urbanization. In addition, activities to raise awareness- about floods, e.g., “living with floods”, in the Mekong Delta should also consider health risk issues.

  2. Microbial Risk Assessment of Tidal−Induced Urban Flooding in Can Tho City (Mekong Delta, Vietnam)

    Science.gov (United States)

    Huynh, Thi Thao Nguyen; Van der Steen, Peter

    2017-01-01

    Public health risks from urban flooding are a global concern. Contaminated floodwater may expose residents living in cities as they are in direct contact with the water. However, the recent literature does not provide much information about this issue, especially for developing countries. In this paper, the health risk due to a flood event occurred in Can Tho City (Mekong Delta, Vietnam) on 7 October 2013 was investigated. The Quantitative Microbial Risk Assessment method was used in this study. The data showed that the pathogen concentrations were highly variable during the flood event and exceeded water standards for surface water. Per 10,000 people in contact with the floodwater, we found Salmonella caused the highest number of infections to adults and children (137 and 374, respectively), while E. coli caused 4 and 12 cases, per single event, respectively. The results show that further investigations on health risk related to flood issues in Can Tho City are required, especially because of climate change and urbanization. In addition, activities to raise awareness- about floods, e.g., “living with floods”, in the Mekong Delta should also consider health risk issues. PMID:29189715

  3. Microbial Risk Assessment of Tidal-Induced Urban Flooding in Can Tho City (Mekong Delta, Vietnam).

    Science.gov (United States)

    Nguyen, Hong Quan; Huynh, Thi Thao Nguyen; Pathirana, Assela; Van der Steen, Peter

    2017-11-30

    Public health risks from urban flooding are a global concern. Contaminated floodwater may expose residents living in cities as they are in direct contact with the water. However, the recent literature does not provide much information about this issue, especially for developing countries. In this paper, the health risk due to a flood event occurred in Can Tho City (Mekong Delta, Vietnam) on 7 October 2013 was investigated. The Quantitative Microbial Risk Assessment method was used in this study. The data showed that the pathogen concentrations were highly variable during the flood event and exceeded water standards for surface water. Per 10,000 people in contact with the floodwater, we found Salmonella caused the highest number of infections to adults and children (137 and 374, respectively), while E. coli caused 4 and 12 cases, per single event, respectively. The results show that further investigations on health risk related to flood issues in Can Tho City are required, especially because of climate change and urbanization. In addition, activities to raise awareness- about floods, e.g., "living with floods", in the Mekong Delta should also consider health risk issues.

  4. Occurrence and Dissipation of the Antibiotics Sulfamethoxazole, Sulfadiazine, Trimethoprim, and Enrofloxacin in the Mekong Delta, Vietnam

    Science.gov (United States)

    Nguyen Dang Giang, Chau; Sebesvari, Zita; Renaud, Fabrice; Rosendahl, Ingrid; Hoang Minh, Quang; Amelung, Wulf

    2015-01-01

    The Mekong Delta in Vietnam has seen a rapid development and intensification of aquaculture in the last decades, with a corresponding widespread use of antibiotics. This study provides information on current antibiotic use in freshwater aquaculture, as well as on resulting antibiotic concentrations in the aquatic environment of the Mekong Delta. Two major production steps, fish hatcheries and mature fish cultivation, were surveyed (50 fish farm interviews) for antibiotic use. Different water sources, including surface water, groundwater and piped water (164 water samples) were systematically screened for antibiotic residues. To better understand antibiotic fate under tropical conditions, the dissipation behavior of selected antibiotics in the aquatic environment was investigated for the first time in mesocosm experiments. None of the investigated antibiotics were detected in groundwater and piped water samples. Surface water, which is still often used for drinking and domestic purposes by local populations, contained median concentrations of 21 ng L-1 sulfamethoxazole (SMX), 4 ng L-1 sulfadiazine (SDZ), 17 ng L-1 trimethoprim (TRIM), and 12 ng L-1 enrofloxacin (ENRO). These concentrations were lower than the predicted no effect concentrations (PNECs) and minimum inhibitory concentrations (MICs), suggesting limited antibiotic-related risk to aquatic ecosystems in the monitored systems. The dissipation half-lives of the studied antibiotics ranged from aquatic environment, yet the persistence of these antibiotics is of concern and might lead to chronic exposure of aquatic organisms as well as humans. PMID:26135396

  5. Hydrogeologic reconnaissance of the Mekong Delta in South Vietnam and Cambodia

    Science.gov (United States)

    Anderson, Henry R.

    1978-01-01

    The present report describes the results of a hydrogeologic reconnaissance in the Mekong Delta region by the writer, a hydrogeologist of the U.S. Geological Survey, while on assignment as an adviser to the Vietnamese Directorate of Water Supply from October 1968 to April 1970 under the auspices of the U.s. Agency for International Development. The delta of the Mekong River, comprising an area of about 70,000 square kilometres in South Vietnam and Cambodia, is an almost featureless plain rising gradually from sea level to about 5 metres above sea level at its apex 300 kilometres inland. Most of the shallow ground water in the Holocene Alluvium of the delta in Vietnam is brackish or saline down to depths of 50 to 100 metres. Moreover, in the Dong Thap Mu?oi (Plain of Reeds) the shallow ground water is alum-bearing. Locally, however, perched bodies of fresh ground water occur in ancient beach and dune ridges and are tapped by shallow dug wells or pits for village and domestic water supply. The Old Alluvium beneath the lower delta contains freshwater in some areas, notably in the Ca Mau Peninsula and adjacent areas, in the viciniy of Bau Xau near Saigon, and in the Tinh Long An area. Elsewhere in the lower delta both the Holocene and Old Alluvium may contain brackish or saline water from the land surface to depths of as much as 568 metres, as for example in Tinh Vinh Binh. Ground water in the outcrop area of Old Alluvium northwest of Saigon is generally fresh and potable, but high iron and low pH are locally troublesome. Although considerable exploratory drilling for ground water down to depths of as much as 568 metres has already been completed, large areas of the delta remain yet to be explored before full development of the ground-water potential can be realized. With careful development and controlled management to avoid saltwater contamination, however, it is estimated that freshwater aquifers could provide approximately 80 percent of existing needs for village

  6. Clonal Occurrence of Salmonella Weltevreden in Cultured Shrimp in the Mekong Delta, Vietnam

    Science.gov (United States)

    Noor Uddin, Gazi Md.; Larsen, Marianne Halberg; Barco, Lisa; Minh Phu, Tran; Dalsgaard, Anders

    2015-01-01

    This study investigated the occurrence, serovar and antimicrobial resistance of Salmonella spp. in shrimp samples from intensive and extensive farms located in three different provinces in the Mekong Delta, Vietnam. Shrimp from 11 of the 48 farms all contained S. Weltevreden, except for one farm yielding S. Agona, with no difference in Salmonella occurrence between the two production systems. Pulsed field gel electrophoresis (PFGE) of S. Weltevreden showed closely related XbaI pulse types, suggesting a clonal relationship despite the farms and shrimp samples being epidemiologically unrelated. S. Weltevreden was susceptible to most antimicrobials tested, with a few strains being resistant to florfenicol, chloramphenicol, sulfamethoxazole or trimethoprim. Future studies of the ecology of S. Weltevreden should establish if this serovar may survive better and even multiply in warm-water shrimp farm environments compared to other Salmonella serovars. PMID:26222547

  7. Clonal Occurrence of Salmonella Weltevreden in Cultured Shrimp in the Mekong Delta, Vietnam.

    Directory of Open Access Journals (Sweden)

    Gazi Md Noor Uddin

    Full Text Available This study investigated the occurrence, serovar and antimicrobial resistance of Salmonella spp. in shrimp samples from intensive and extensive farms located in three different provinces in the Mekong Delta, Vietnam. Shrimp from 11 of the 48 farms all contained S. Weltevreden, except for one farm yielding S. Agona, with no difference in Salmonella occurrence between the two production systems. Pulsed field gel electrophoresis (PFGE of S. Weltevreden showed closely related XbaI pulse types, suggesting a clonal relationship despite the farms and shrimp samples being epidemiologically unrelated. S. Weltevreden was susceptible to most antimicrobials tested, with a few strains being resistant to florfenicol, chloramphenicol, sulfamethoxazole or trimethoprim. Future studies of the ecology of S. Weltevreden should establish if this serovar may survive better and even multiply in warm-water shrimp farm environments compared to other Salmonella serovars.

  8. Temporal fluctuation of multidrug resistant salmonella typhi haplotypes in the mekong river delta region of Vietnam.

    Directory of Open Access Journals (Sweden)

    Kathryn E Holt

    2011-01-01

    Full Text Available typhoid fever remains a public health problem in Vietnam, with a significant burden in the Mekong River delta region. Typhoid fever is caused by the bacterial pathogen Salmonella enterica serovar Typhi (S. Typhi, which is frequently multidrug resistant with reduced susceptibility to fluoroquinolone-based drugs, the first choice for the treatment of typhoid fever. We used a GoldenGate (Illumina assay to type 1,500 single nucleotide polymorphisms (SNPs and analyse the genetic variation of S. Typhi isolated from 267 typhoid fever patients in the Mekong delta region participating in a randomized trial conducted between 2004 and 2005.the population of S. Typhi circulating during the study was highly clonal, with 91% of isolates belonging to a single clonal complex of the S. Typhi H58 haplogroup. The patterns of disease were consistent with the presence of an endemic haplotype H58-C and a localised outbreak of S. Typhi haplotype H58-E2 in 2004. H58-E2-associated typhoid fever cases exhibited evidence of significant geo-spatial clustering along the Sông H u branch of the Mekong River. Multidrug resistance was common in the established clone H58-C but not in the outbreak clone H58-E2, however all H58 S. Typhi were nalidixic acid resistant and carried a Ser83Phe amino acid substitution in the gyrA gene.the H58 haplogroup dominates S. Typhi populations in other endemic areas, but the population described here was more homogeneous than previously examined populations, and the dominant clonal complex (H58-C, -E1, -E2 observed in this study has not been detected outside Vietnam. IncHI1 plasmid-bearing S. Typhi H58-C was endemic during the study period whilst H58-E2, which rarely carried the plasmid, was only transient, suggesting a selective advantage for the plasmid. These data add insight into the outbreak dynamics and local molecular epidemiology of S. Typhi in southern Vietnam.

  9. Occurrence and Dissipation of the Antibiotics Sulfamethoxazole, Sulfadiazine, Trimethoprim, and Enrofloxacin in the Mekong Delta, Vietnam.

    Directory of Open Access Journals (Sweden)

    Chau Nguyen Dang Giang

    Full Text Available The Mekong Delta in Vietnam has seen a rapid development and intensification of aquaculture in the last decades, with a corresponding widespread use of antibiotics. This study provides information on current antibiotic use in freshwater aquaculture, as well as on resulting antibiotic concentrations in the aquatic environment of the Mekong Delta. Two major production steps, fish hatcheries and mature fish cultivation, were surveyed (50 fish farm interviews for antibiotic use. Different water sources, including surface water, groundwater and piped water (164 water samples were systematically screened for antibiotic residues. To better understand antibiotic fate under tropical conditions, the dissipation behavior of selected antibiotics in the aquatic environment was investigated for the first time in mesocosm experiments. None of the investigated antibiotics were detected in groundwater and piped water samples. Surface water, which is still often used for drinking and domestic purposes by local populations, contained median concentrations of 21 ng L-1 sulfamethoxazole (SMX, 4 ng L-1 sulfadiazine (SDZ, 17 ng L-1 trimethoprim (TRIM, and 12 ng L-1 enrofloxacin (ENRO. These concentrations were lower than the predicted no effect concentrations (PNECs and minimum inhibitory concentrations (MICs, suggesting limited antibiotic-related risk to aquatic ecosystems in the monitored systems. The dissipation half-lives of the studied antibiotics ranged from <1 to 44 days, depending on the availability of sunlight and sediment. Among the studied antibiotics TRIM was the most persistent in water systems. TRIM was not susceptible to photodegradation, while the dissipation of ENRO and SDZ was influenced by photolysis. The recorded dissipation models gave good predictions of the occurrence and concentrations of TRIM, ENRO and SDZ in surface water. In summary, the currently measured concentrations of the investigated antibiotics are unlikely to cause immediate risks

  10. Occurrence and Dissipation of the Antibiotics Sulfamethoxazole, Sulfadiazine, Trimethoprim, and Enrofloxacin in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Nguyen Dang Giang, Chau; Sebesvari, Zita; Renaud, Fabrice; Rosendahl, Ingrid; Hoang Minh, Quang; Amelung, Wulf

    2015-01-01

    The Mekong Delta in Vietnam has seen a rapid development and intensification of aquaculture in the last decades, with a corresponding widespread use of antibiotics. This study provides information on current antibiotic use in freshwater aquaculture, as well as on resulting antibiotic concentrations in the aquatic environment of the Mekong Delta. Two major production steps, fish hatcheries and mature fish cultivation, were surveyed (50 fish farm interviews) for antibiotic use. Different water sources, including surface water, groundwater and piped water (164 water samples) were systematically screened for antibiotic residues. To better understand antibiotic fate under tropical conditions, the dissipation behavior of selected antibiotics in the aquatic environment was investigated for the first time in mesocosm experiments. None of the investigated antibiotics were detected in groundwater and piped water samples. Surface water, which is still often used for drinking and domestic purposes by local populations, contained median concentrations of 21 ng L-1 sulfamethoxazole (SMX), 4 ng L-1 sulfadiazine (SDZ), 17 ng L-1 trimethoprim (TRIM), and 12 ng L-1 enrofloxacin (ENRO). These concentrations were lower than the predicted no effect concentrations (PNECs) and minimum inhibitory concentrations (MICs), suggesting limited antibiotic-related risk to aquatic ecosystems in the monitored systems. The dissipation half-lives of the studied antibiotics ranged from antibiotics TRIM was the most persistent in water systems. TRIM was not susceptible to photodegradation, while the dissipation of ENRO and SDZ was influenced by photolysis. The recorded dissipation models gave good predictions of the occurrence and concentrations of TRIM, ENRO and SDZ in surface water. In summary, the currently measured concentrations of the investigated antibiotics are unlikely to cause immediate risks to the aquatic environment, yet the persistence of these antibiotics is of concern and might lead to

  11. Pesticide pollution of multiple drinking water sources in the Mekong Delta, Vietnam: evidence from two provinces.

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    Chau, N D G; Sebesvari, Z; Amelung, W; Renaud, F G

    2015-06-01

    Pollution of drinking water sources with agrochemicals is often a major threat to human and ecosystem health in some river deltas, where agricultural production must meet the requirements of national food security or export aspirations. This study was performed to survey the use of different drinking water sources and their pollution with pesticides in order to inform on potential exposure sources to pesticides in rural areas of the Mekong River delta, Vietnam. The field work comprised both household surveys and monitoring of 15 frequently used pesticide active ingredients in different water sources used for drinking (surface water, groundwater, water at public pumping stations, surface water chemically treated at household level, harvested rainwater, and bottled water). Our research also considered the surrounding land use systems as well as the cropping seasons. Improper pesticide storage and waste disposal as well as inadequate personal protection during pesticide handling and application were widespread amongst the interviewed households, with little overall risk awareness for human and environmental health. The results show that despite the local differences in the amount and frequency of pesticides applied, pesticide pollution was ubiquitous. Isoprothiolane (max. concentration 8.49 μg L(-1)), fenobucarb (max. 2.32 μg L(-1)), and fipronil (max. 0.41 μg L(-1)) were detected in almost all analyzed water samples (98 % of all surface samples contained isoprothiolane, for instance). Other pesticides quantified comprised butachlor, pretilachlor, propiconazole, hexaconazole, difenoconazole, cypermethrin, fenoxapro-p-ethyl, tebuconazole, trifloxystrobin, azoxystrobin, quinalphos, and thiamethoxam. Among the studied water sources, concentrations were highest in canal waters. Pesticide concentrations varied with cropping season but did not diminish through the year. Even in harvested rainwater or purchased bottled water, up to 12 different pesticides were detected at

  12. Application of the Water Needs Index: Can Tho City, Mekong Delta, Vietnam

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    Moglia, Magnus; Neumann, Luis E.; Alexander, Kim S.; Nguyen, Minh N.; Sharma, Ashok K.; Cook, Stephen; Trung, Nguyen H.; Tuan, Dinh D. A.

    2012-10-01

    SummaryProvision of urban water supplies to rapidly growing cities of South East Asia is difficult because of increasing demand for limited water supplies, periodic droughts, and depletion and contamination of surface and groundwater. In such adverse environments, effective policy and planning processes are required to secure adequate water supplies. Developing a Water Needs Index reveals key elements of the complex urban water supply by means of a participatory approach for rapid and interdisciplinary assessment. The index uses deliberative interactions with stakeholders to create opportunities for mutual understanding, confirmation of constructs and capacity building of all involved. In Can Tho City, located at the heart of the Mekong delta in Vietnam, a Water Needs Index has been developed with local stakeholders. The functional attributes of the Water Needs Index at this urban scale have been critically appraised. Systemic water issues, supply problems, health issues and inadequate, poorly functioning infrastructure requiring attention from local authorities have been identified. Entrenched social and economic inequities in access to water and sanitation, as well as polluting environmental management practices has caused widespread problems for urban populations. The framework provides a common language based on systems thinking, increased cross-sectoral communication, as well as increased recognition of problem issues; this ought to lead to improved urban water management. Importantly, the case study shows that the approach can help to overcome biases of local planners based on their limited experience (information black spots), to allow them to address problems experienced in all areas of the city.

  13. Copper use and accumulation in catfish culture in the Mekong Delta, Vietnam.

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    Marcussen, Helle; Løjmand, Helle; Dalsgaard, Anders; Hai, Dao M; Holm, Peter E

    2014-01-01

    Aquaculture of Pangasius hypophthalmus (striped catfish) in Vietnam reached 1.1 million tonnes in 2011 and catfish fillets are exported worldwide. The intensive cultures of catfish mainly in earth ponds have made it necessary to apply CuSO4 and other chemicals to control external parasites and other pathogens. However, accumulation of Cu in aquaculture ponds may pose a hazard to growth of fish or to the aquatic environment. The aim of this study was to determine accumulation of Cu in sediment, water and fish in a catfish pond with a history of repeated treatment with CuSO4 in the Mekong Delta, Vietnam. Copper concentrations in pond sediment were in the interval 21.3-45.7 mg kg(-1) dw and did not exceed the Vietnamese values for soil to be used for agricultural production (70 mg kg(-1) dw.). During three samplings the total mean concentration of Cu in pond water (4 μg L(-1)) did not exceed the LC50-value (70 μg L(-1)) for catfish and the mean dissolved concentration of Cu (0.986 μg L(-1)) did not seem to constitute a risk for the stability of the aquatic ecosystem. No significant variation in Cu concentrations between sampling sites in the pond and depth of sediment profile were determined. The accumulation of Cu in catfish was highest in the liver compared to the skin, gills and muscle tissue. With the current practice of removing pond sludge three to four times during a production cycle little if any Cu seems to accumulate in catfish ponds despite repeated anti-parasite treatments with CuSO4. Further studies are needed to assess the eco-toxicity and impact on agricultural production when pond sediment is discharged into aquatic recipients and used as soil fertilizer.

  14. Factors affecting farmers' adoption of integrated rice-fish farming systems in the Mekong delta, Vietnam

    NARCIS (Netherlands)

    Bosma, R.H.; Nhan, D.K.; Udo, H.M.J.; Kaymak, U.

    2012-01-01

    This study investigated the determinants of the adoption of improved rice–fish farming systems in the Mekong delta to support policy making, agricultural land-use planning and extension of integrated rice–fish farming. Recently these systems have been referred to as adaptations to climate change,

  15. Modern sedimentation and morphology of the subaqueous Mekong Delta, Southern Vietnam

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    Unverricht, Daniel; Szczuciński, Witold; Stattegger, Karl; Jagodziński, Robert; Le, Xuan Thuyen; Kwong, Laval Liong Wee

    2013-11-01

    The Mekong River Delta is among the Asian mega-deltas and is influenced by various factors including tides (meso-tidal system), waves, coastal currents, monsoon-driven river discharge and human impact (agriculture, fishing, sand dredging, tourism). The present study aims to document the seafloor relief, sediment distribution and sediment accumulation rates to interpret modern sediment transport directions and main sedimentation processes in the subaqueous Mekong Delta. The major results of this investigation include the detection of two delta fronts 200 km apart, one at the mouth of the Bassac River (the biggest branch of the Mekong Delta) and the other around Cape Ca Mau (most south-western end of the Mekong Delta). Additionally, a large channel system runs in the subaqueous delta platform parallel to the shore and between the two fronts. The sediment accumulation rates vary greatly according to the location in the subaqueous delta and have reached up to 10 cm/yr for the last century. A cluster analysis of surface sediment samples revealed two different sediment types within the delta including a well-sorted sandy sediment and a poorly sorted, silty sediment. In addition, a third end member with medium to coarse sand characterised the distant parts of the delta at the transition to the open shelf. The increase of organic matter and carbonate content to the bottom set area and other sedimentary features such as shell fragments, foraminiferas and concretions of palaeo-soils that do not occur in delta sediments, supported grain size-based classification. Beginning in front of the Bassac River mouth, sedimentary pattern indicates clockwise sediment transport alongshore in the western direction to a broad topset area and the delta front around Cape Ca Mau. Our results clearly show the large lateral variability of the subaqueous Mekong Delta that is further complicated by strong monsoon-driven seasonality. River, tidal and wave forcing vary at local and seasonal scales

  16. How Important Are Rats As Vectors of Leptospirosis in the Mekong Delta of Vietnam?

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    Loan, Hoang Kim; Van Cuong, Nguyen; Takhampunya, Ratree; Kiet, Bach Tuan; Campbell, James; Them, Lac Ngoc; Bryant, Juliet E.; Tippayachai, Bousaraporn; Van Hoang, Nguyen; Morand, Serge; Hien, Vo Be

    2015-01-01

    Abstract Leptospirosis is a zoonosis known to be endemic in the Mekong Delta of Vietnam, even though clinical reports are uncommon. We investigated leptospira infection in rats purchased in food markets during the rainy season (October) (n=150), as well as those trapped during the dry season (February–March) (n=125) in the region using RT-PCR for the lipL32 gene, confirmed by 16S rRNA, as well as by the microscopic agglutination test (MAT). Results were compared with the serovar distribution of human cases referred from Ho Chi Minh City hospitals (2004–2012) confirmed by MAT (n=45). The MAT seroprevalence among rats was 18.3%. The highest MAT seroprevalence corresponded, in decreasing order, to: Rattus norvegicus (33.0%), Bandicota indica (26.5%), Rattus tanezumi (24.6%), Rattus exulans (14.3%), and Rattus argentiventer (7.1%). The most prevalent serovars were, in descending order: Javanica (4.6% rats), Lousiana (4.2%), Copenageni (4.2%), Cynopterie (3.7%), Pomona (2.9%), and Icterohaemorrhagiae (2.5%). A total of 16 rats (5.8%) tested positive by RT-PCR. Overall, larger rats tended to have a higher prevalence of detection. There was considerable agreement between MAT and PCR (kappa=0.28 [0.07–0.49]), although significantly more rats were positive by MAT (McNemar 29.9 (pgeographically linked co-sampling of humans and animals to establish the main sources of leptospirosis in the region. PMID:25629781

  17. Effects of local and spatial conditions on the quality of harvested rainwater in the Mekong Delta, Vietnam

    International Nuclear Information System (INIS)

    Wilbers, Gert-Jan; Sebesvari, Zita; Rechenburg, Andrea; Renaud, Fabrice G.

    2013-01-01

    The objective of this study was to assess the quality of harvested rainwater in the Mekong Delta (MD), Vietnam for local (roof types, storage system and duration) and spatial (proximity of industry, main roads, coastline) conditions. 78 harvested rainwater samples were collected in the MD and analyzed for pH, turbidity, TDS, COD, nutrients (NH 4 , NO 3 , NO 2 , o-PO 4 ), trace metals and coliforms. The results show that thatch roofs lead to an increase of pollutants like COD (max 23.2 mgl −1 ) and turbidity (max 10.1 mgl −1 ) whereas galvanized roofs lead to an increase of Zn (max 2.2 mgl −1 ). The other local and spatial parameters had no or only minor influence on the quality of household harvested rainwater. However, lead (Pb) (max. 16.9 μgl −1 ) and total coliforms (max. 102 500 CFU100 ml −1 ) were recorded at high concentrations, probably due to a variety of household-specific conditions such as rainwater storage, collection and handling practices. -- Highlights: •Rainwater is a main drinking water source in the Mekong Delta. •Harvested rainwater is severely polluted for turbidity, lead and (total) coliforms. •Roof types significantly affect the quality of harvested rainwater. •Effects of household conditions on harvested rainwater quality should be further assessed. •Harvested rainwater is in potential a safe drinking water resource in the Mekong Delta. -- Concentrations of lead and total coliforms in household-harvested rainwater in the Mekong Delta exceed drinking water guidelines in 17% and 92% of the samples, respectively

  18. Direct and indirect influences of the weaver ant Oecophylla smaragdina on citrus farmers pest perceptions and management practices in the Mekong Delta, Vietnam.

    NARCIS (Netherlands)

    Mele, van P.; Cuc, N.T.T.; Huis, van A.

    2002-01-01

    In the Mekong Delta, Vietnam, the predatory weaver ant Oecophylla smaragdina was abundant in about 75␘f the sweet orange and 25␘f the Tieu mandarin orchards. With a three-level scale (low, moderate, high), farmers assessed the incidence, severity and yield loss of fruit caused by major pests. With

  19. Water Supply or ‘Beautiful Latrines’? Microcredit for Rural Water Supply and Sanitation in the Mekong Delta, Vietnam

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    Nadine Reis

    2012-01-01

    Full Text Available Around half of the Mekong Delta’s rural population lacks year-round access to clean water. In combination with inadequate hygiene and poor sanitation this creates a high risk of diseases. Microcredit schemes are a popular element in addressing such problems on the global policy level. The present paper analyses the contradictory results of such a microcredit programme for rural water supply and sanitation in the context of the Mekong Delta, Vietnam, through a qualitative study primarily based on semi-structured interviews in rural communes of Can Tho City. We come to the conclusion that the programme has a positive effect regarding the safer disposal of human excreta as well as surface water quality, but a marginal impact on poverty reduction as it only reaches better-off households already having access to clean water. The paper shows how the outcome of rural water supply and sanitation policies are strongly influenced by the local ecological, technological, and social settings, in particular by stakeholders’ interests. The authors challenge the assumption that water supply and sanitation should be integrated into the same policy in all circumstances. ----- Etwa die Hälfte der ländlichen Bevölkerung des Mekong-Deltas hat nicht das ganze Jahr über Zugang zu sauberem Wasser. Zusammen mit unzureichender Hygiene und mangelnder sanitärer Grundversorgung erhöht diese Situation das Krankheitsrisiko. Auf globaler Ebene sind Mikrokreditprogramme eine gefragte Strategie, um diese Probleme zu behandeln. Der vorliegende Artikel analysiert die widersprüchlichen Ergebnisse eines solchen Mikrokreditprogramms für ländliche Wasser- und sanitäre Grundversorgung im Mekong-Delta in Vietnam im Rahmen einer qualitativen Studie, die auf halbstrukturierten Interviews im Raum Can Tho City basiert. Die Studie kommt zu dem Schluss, dass das Programm eine positive Wirkung in Bezug auf die sichere Entsorgung von Fäkalien und die Qualität des Regenwassers

  20. Salt intrusion in multi-channel estuaries: a case study in the Mekong Delta, Vietnam

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    A. D. Nguyen

    2006-01-01

    Full Text Available There is a well-tested theory for the computation of salt intrusion in alluvial estuaries that is fully analytical and predictive. The theory uses analytical equations to predict the mixing behaviour of the estuary based on measurable quantities, such as channel topography, river discharge and tidal characteristics. It applies to single-channel topographies and estuaries that demonstrate moderate tidal damping. The Mekong delta is a multi-channel estuary where the tide is damped due to a relatively strong river discharge (in the order of 2000 m3/s, even during the dry season. As a result the Mekong is a strongly riverine estuary. This paper aims to test if the theory can be applied to such a riverine multi-channel estuary, and to see if possible adjustments or generalisations need to be made. The paper presents salt intrusion measurements that were done by moving boat in 2005, to which the salt intrusion model was calibrated. The theory has been expanded to cater for tidal damping. Subsequently the model has been validated with observations made at fixed locations over the years 1998 and 1999. Finally it has been tested whether the Mekong calibration fits the overall predictive equations derived in other estuaries. The test has been successful and led to a slight adjustment of the predictive equation to cater for estuaries that experience a sloping bottom.

  1. Release of arsenic to deep groundwater in the Mekong Delta, Vietnam, linked to pumping-induced land subsidence.

    Science.gov (United States)

    Erban, Laura E; Gorelick, Steven M; Zebker, Howard A; Fendorf, Scott

    2013-08-20

    Deep aquifers in South and Southeast Asia are increasingly exploited as presumed sources of pathogen- and arsenic-free water, although little is known of the processes that may compromise their long-term viability. We analyze a large area (>1,000 km(2)) of the Mekong Delta, Vietnam, in which arsenic is found pervasively in deep, Pliocene-Miocene-age aquifers, where nearly 900 wells at depths of 200-500 m are contaminated. There, intensive groundwater extraction is causing land subsidence of up to 3 cm/y as measured using satellite-based radar images from 2007 to 2010 and consistent with transient 3D aquifer simulations showing similar subsidence rates and total subsidence of up to 27 cm since 1988. We propose a previously unrecognized mechanism in which deep groundwater extraction is causing interbedded clays to compact and expel water containing dissolved arsenic or arsenic-mobilizing solutes (e.g., dissolved organic carbon and competing ions) to deep aquifers over decades. The implication for the broader Mekong Delta region, and potentially others like it across Asia, is that deep, untreated groundwater will not necessarily remain a safe source of drinking water.

  2. Pesticide management and their residues in sediments and surface and drinking water in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Toan, Pham Van; Sebesvari, Zita; Bläsing, Melanie; Rosendahl, Ingrid; Renaud, Fabrice G

    2013-05-01

    Public concern in Vietnam is increasing with respect to pesticide pollution of the environment and of drinking water resources. While established monitoring programs in the Mekong Delta (MD) focus on the analysis of organochlorines and some organophosphates, the environmental concentrations of more recently used pesticides such as carbamates, pyrethroides, and triazoles are not monitored. In the present study, household level pesticide use and management was therefore surveyed and combined with a one year environmental monitoring program of thirteen relevant pesticides (buprofezin, butachlor, cypermethrin, α-endosulfan, β-endosulfan, endosulfan-sulfate, fenobucarb, fipronil, isoprothiolane, pretilachlor, profenofos, propanil, and propiconazole) in surface water, soil, and sediment samples. The surveys showed that household level pesticide management remains suboptimal in the Mekong Delta. As a consequence, a wide range of pesticide residues were present in water, soil, and sediments throughout the monitoring period. Maximum concentrations recorded were up to 11.24 μg l(-1) in water for isoprothiolane and up to 521 μg kg(-1) dm in sediment for buprofezin. Annual average concentrations ranged up to 3.34 μg l(-1) in water and up to 135 μg kg(-1) dm in sediment, both for isoprothiolane. Occurrence of pesticides in the environment throughout the year and co-occurrence of several pesticides in the samples indicate a considerable chronic exposure of biota and humans to pesticides. This has a high relevance in the delta as water for drinking is often extracted from canals and rivers by rural households (GSO, 2005, and own surveys). The treatment used by the households for preparing surface water prior to consumption (flocculation followed by boiling) is insufficient for the removal of the studied pesticides and boiling can actually increase the concentration of non-volatile pollutants. Copyright © 2012 Elsevier B.V. All rights reserved.

  3. Promotion of biogas plant application in the Mekong Delta of Vietnam

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    Nguyen, Vo Chau Ngan

    2012-06-11

    The study focuses on waste management in the Mekong Delta of Vietnam (MD) through the application of biogas plants to livestock and agricultural waste treatment. As the biggest ''rice bowl'' in the country, the MD produces more than 50% of the national aquaagricultural production, in which livestock sector contributes more than 20% of agricultural growth. The increasing livestock sector, however, has been attributed to the environmental problems, particularly in relation to the free discharge of waste/wastewater into the water open sources in the region. Such the environmental problems have become more serious in the rural areas of the MD where the water from the canal network is used as the main water supply sources to the 60% of local communities. Biogas technology was introduced as an environmentally-friendly treatment for animal and human wastes in the MD in the 1980s. Nonetheless, the number of biogas plants already constructed is considerably limited in comparison to the actual demand on livestock waste treatment in the region. The study, therefore, aims at seeking for possible solutions to promote the widespread application of biogas plants in the MD in order to help improve the sanitary condition of the local communities. In this study, a survey of 110 farmers was conducted in the three provinces of the MD. The farmers included biogas user households, non-biogas user households, and biogas masons. The interviews with the three groups of farmers provided profound and comprehensive information on the actual application and demand of biogas plants in the MD. Accordingly, a large number of the local people have acknowledged the great benefits of biogas application. However, the interviews revealed that there are some impediments to the development of biogas plants in the region such as high investment cost, shortage of input to biogas plants, and limited possibilities of application of by-products from biogas plants. In an attempt to search

  4. Farmers' Perceived Risks of Climate Change and Influencing Factors: A Study in the Mekong Delta, Vietnam

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    Le Dang, Hoa; Li, Elton; Nuberg, Ian; Bruwer, Johan

    2014-08-01

    Many countries are confronting climate change that threatens agricultural production and farmers' lives. Farmers' perceived risks of climate change and factors influencing those perceived risks are critical to their adaptive behavior and well-planned adaptation strategies. However, there is limited understanding of these issues. In this paper, we attempt to quantitatively measure farmers' perceived risks of climate change and explore the influences of risk experience, information, belief in climate change, and trust in public adaptation to those perceived risks. Data are from structured interviews with 598 farmers in the Mekong Delta. The study shows that perceived risks to production, physical health, and income dimensions receive greater priority while farmers pay less attention to risks to happiness and social relationships. Experiences of the events that can be attributed to climate change increase farmers' perceived risks. Information variables can increase or decrease perceived risks, depending on the sources of information. Farmers who believe that climate change is actually happening and influencing their family's lives, perceive higher risks in most dimensions. Farmers who think that climate change is not their concern but the government's, perceive lower risks to physical health, finance, and production. As to trust in public adaptation, farmers who believe that public adaptive measures are well co-ordinated, perceive lower risks to production and psychology. Interestingly, those who believe that the disaster warning system is working well, perceive higher risks to finance, production, and social relationships. Further attention is suggested for the quality, timing, and channels of information about climate change and adaptation.

  5. Farmers' perceived risks of climate change and influencing factors: a study in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Le Dang, Hoa; Li, Elton; Nuberg, Ian; Bruwer, Johan

    2014-08-01

    Many countries are confronting climate change that threatens agricultural production and farmers' lives. Farmers' perceived risks of climate change and factors influencing those perceived risks are critical to their adaptive behavior and well-planned adaptation strategies. However, there is limited understanding of these issues. In this paper, we attempt to quantitatively measure farmers' perceived risks of climate change and explore the influences of risk experience, information, belief in climate change, and trust in public adaptation to those perceived risks. Data are from structured interviews with 598 farmers in the Mekong Delta. The study shows that perceived risks to production, physical health, and income dimensions receive greater priority while farmers pay less attention to risks to happiness and social relationships. Experiences of the events that can be attributed to climate change increase farmers' perceived risks. Information variables can increase or decrease perceived risks, depending on the sources of information. Farmers who believe that climate change is actually happening and influencing their family's lives, perceive higher risks in most dimensions. Farmers who think that climate change is not their concern but the government's, perceive lower risks to physical health, finance, and production. As to trust in public adaptation, farmers who believe that public adaptive measures are well co-ordinated, perceive lower risks to production and psychology. Interestingly, those who believe that the disaster warning system is working well, perceive higher risks to finance, production, and social relationships. Further attention is suggested for the quality, timing, and channels of information about climate change and adaptation.

  6. Assessing the impact of sea level rise due to climate change on seawater intrusion in Mekong Delta, Vietnam.

    Science.gov (United States)

    Vu, D T; Yamada, T; Ishidaira, H

    2018-03-01

    In the context of climate change, salinity intrusion into rivers has been, and will be, one of the most important issues for coastal water resources management. A combination of changes, including increased temperature, change in regional rainfall, especially sea level rise (SLR) related to climate change, will have significant impacts on this phenomenon. This paper presents the outcomes of a study conducted in the Mekong Delta of Vietnam (MKD) for evaluating the effect of sea water intrusion under a new SLR scenario. Salinity intrusion was simulated by one-dimensional (1D) modeling. The relative sea level projection was constructed corresponding to the RCP 6.0 emission scenario for MKD based on the statistical downscaling method. The sea level in 2050 is projected to increase from 25 cm to 30 cm compared to the baseline period (in 2000). Furthermore, the simulated results suggested that salinity greater than 4 g/l, which affects rice yield, will intrude up to 50-60 km into the river. Approximately 30,000 ha of agricultural area will be affected if the sea level rise is 30 cm.

  7. Learning from the Neighbors: Economic and Environmental Impacts from Intensive Shrimp Farming in the Mekong Delta of Vietnam

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    Thuy T.H. Nguyen

    2010-07-01

    Full Text Available Intensive shrimp farming is a lucrative and highly risky business. Before entering this industry, most farmers spend time observing the operation of pilot farms. This stage is important to master essential techniques and judge the profitability and risk associated with shrimp farming. Learning is a complex process that leads to misconceptions about the nature of short-term and long-term risks. This paper uses computer simulation to illuminate the dynamic nature of the learning processes, land conversion, shrimp production and environmental contamination. The model is based on conditions of the Dai Hoa Loc Commune in the Mekong Delta of Vietnam. Initial simulations match statistical data by revealing the high risk: high initial profits from the pilot farms followed by conversion from rice land to shrimp farms. When rapid conversion occurs, the region is vulnerable to excessive accumulation of nutrients, a decline in shrimp yields and financial failure. In contrast, low stock densities deliver a lower profit which is insufficient to stimulate mass land conversion. The paper concludes with testing recovery strategies for farmers who have suffered the longer term impacts of high stocking density. Results show that yield recovery is possible by improving the channel and imposing regulatory control over stocking density.

  8. Spatial and temporal variability of surface water pollution in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Wilbers, Gert-Jan; Becker, Mathias; Nga, La Thi; Sebesvari, Zita; Renaud, Fabrice G

    2014-07-01

    Surface water pollution in the Vietnamese Mekong Delta (MD) could threaten human, animal and ecosystem health given the fact that this water source is intensively used for drinking, irrigation and domestic services. We therefore determined the levels of pollution by organic pollutants, salts, metals and microbial indicators by (bi)monthly monitoring of canals between November 2011 and July 2012 at 32 sampling locations, representing fresh and saline/brackish environments. The results were compared with national water quality guidelines, between the studied regions and with water quality data from main waterways. Key factors explaining the observed levels of pollution in surface water were identified through principal component analysis (PCA). Temporal variations due to tidal regime and seasonality were also assessed. Based on regression models, the spatial variability of five water quality parameters was visualized using GIS based maps. Results indicate that pH (max. 8.6), turbidity (max. 461 FTU), maximum concentrations of ammonium (14.7 mg L(-1)), arsenic (44.1 μg L(-1)), barium (157.5 μg L(-1)), chromium (84.7 μg L(-1)), mercury (45.5 μg L(-1)), manganese (1659.7 μg L(-1)), aluminum (14.5 mg L(-1)), iron (17.0 mg L(-1)) and the number of Escherichia coli (87,000 CFU 100 mL(-1)) and total coliforms (2,500,000 CFU 100 mL(-1)) in canals exceed the thresholds set by Vietnamese quality guidelines for drinking and domestic purposes. The PCA showed that i) urbanization; ii) metal leaching from soils; iii) aquaculture; and iv) tidal regime explain 85% of the variance of surface water quality attributes. Significant differences in water quality were found due to daily tidal regime and as a result of seasonality. Surface water quality maps for dissolved oxygen, ammonium, ortho-phosphate, manganese and total coliforms were developed to highlight hot-spot areas of pollution. The results of this study can assist policy makers in developing water management strategies

  9. Integrated freshwater aquaculture, crop and livestock production in the Mekong delta, Vietnam: Determinants and the role of the pond

    NARCIS (Netherlands)

    Nhan, D.K.; Phong, L.T.; Verdegem, M.C.J.; Duong, L.T.; Bosma, R.H.; Little, D.C.

    2007-01-01

    Promotion of integrated aquaculture with agriculture, including crops and livestock (IAA-farming), requires consideration of both bio-physical and socio-economic contexts. The major factors influencing the adoption of IAA-farming by households at three sites in the Mekong delta were identified.

  10. A Phenology-Based Classification of Time-Series MODIS Data for Rice Crop Monitoring in Mekong Delta, Vietnam

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    Nguyen-Thanh Son

    2013-12-01

    Full Text Available Rice crop monitoring is an important activity for crop management. This study aimed to develop a phenology-based classification approach for the assessment of rice cropping systems in Mekong Delta, Vietnam, using Moderate Resolution Imaging Spectroradiometer (MODIS data. The data were processed from December 2000, to December 2012, using empirical mode decomposition (EMD in three main steps: (1 data pre-processing to construct the smooth MODIS enhanced vegetation index (EVI time-series data; (2 rice crop classification; and (3 accuracy assessment. The comparisons between the classification maps and the ground reference data indicated overall accuracies and Kappa coefficients, respectively, of 81.4% and 0.75 for 2002, 80.6% and 0.74 for 2006 and 85.5% and 0.81 for 2012. The results by comparisons between MODIS-derived rice area and rice area statistics were slightly overestimated, with a relative error in area (REA from 0.9–15.9%. There was, however, a close correlation between the two datasets (R2 ≥ 0.89. From 2001 to 2012, the areas of triple-cropped rice increased approximately 31.6%, while those of the single-cropped rain-fed rice, double-cropped irrigated rice and double-cropped rain-fed rice decreased roughly −5.0%, −19.2% and −7.4%, respectively. This study demonstrates the validity of such an approach for rice-crop monitoring with MODIS data and could be transferable to other regions.

  11. Antimicrobial usage in chicken production in the mekong delta of Vietnam

    NARCIS (Netherlands)

    Carrique-Mas, Juan J.; Trung, Nguyen V.; Hoa, Ngo T.; Mai, Ho Huynh; Thanh, Tuyen H.; Campbell, James I.; Wagenaar, Jaap A.; Hardon, Anita; Hieu, Thai Quoc; Schultsz, Constance

    2015-01-01

    Antimicrobials are used extensively in chicken production in Vietnam, but to date no quantitative data are available. A 2012-2013 survey of 208 chicken farms in Tien Giang province, stratified by size (10-200 chickens; >200-2000), was carried out to describe and quantify the use of antibacterial

  12. Antimicrobial usage in chicken production in the Mekong Delta of Vietnam

    NARCIS (Netherlands)

    Carrique-Mas, J.J.; Trung, N.V.; Hoa, N.T.; Mai, H.H.; Thanh, T.H.; Campbell, J.I.; Wagenaar, J.A.; Hardon, A.; Hieu, T.Q.; Schultsz, C.

    2015-01-01

    Antimicrobials are used extensively in chicken production in Vietnam, but to date no quantitative data are available. A 2012-2013 survey of 208 chicken farms in Tien Giang province, stratified by size (10-200 chickens; >200-2000), was carried out to describe and quantify the use of antibacterial

  13. Resilience and livelihood dynamics of shrimp farmers and fishers in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Tran Thi Phung, H.

    2012-01-01

    Shrimp aquaculture and fishery, the two important economic sectors in Vietnam, have been promoted by the government to reduce poverty, provide job opportunities, and to increase exports to support economic development. However, this expansion of fishery and aquaculture has also had negative

  14. Molecular characterization of HIV-1 CRF01_AE in Mekong Delta, Vietnam, and impact of T-cell epitope mutations on HLA recognition (ANRS 12159.

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    Estibaliz Lazaro

    Full Text Available BACKGROUND: To date, 11 HIV-1 subtypes and 48 circulating recombinant forms have been described worldwide. The underlying reason why their distribution is so heterogeneous is not clear. Host genetic factors could partly explain this distribution. The aim of this study was to describe HIV-1 strains circulating in an unexplored area of Mekong Delta, Vietnam, and to assess the impact of optimal epitope mutations on HLA binding. METHODS: We recruited 125 chronically antiretroviral-naive HIV-1-infected subjects from five cities in the Mekong Delta. We performed high-resolution DNA typing of HLA class I alleles, sequencing of Gag and RT-Prot genes and phylogenetic analysis of the strains. Epitope mutations were analyzed in patients bearing the HLA allele restricting the studied epitope. Optimal wild-type epitopes from the Los Alamos database were used as reference. T-cell epitope recognition was predicted using the immune epitope database tool according to three different scores involved in antigen processing (TAP and proteasome scores and HLA binding (MHC score. RESULTS: All sequences clustered with CRF01_AE. HLA class I genotyping showed the predominance of Asian alleles as A*11:01 and B*46:01 with a Vietnamese specificity held by two different haplotypes. The percentage of homology between Mekong and B consensus HIV-1 sequences was above 85%. Divergent epitopes had TAP and proteasome scores comparable with wild-type epitopes. MHC scores were significantly lower in divergent epitopes with a mean of 2.4 (±0.9 versus 2 (±0.7 in non-divergent ones (p<0.0001. CONCLUSIONS: Our study confirms the wide predominance of CRF01_AE in the Mekong Delta where patients harbor a specific HLA pattern. Moreover, it demonstrates the lower MHC binding affinity among divergent epitopes. This weak immune pressure combined with a narrow genetic diversity favors immune escape and could explain why CRF01_AE is still predominant in Vietnam, particularly in the Mekong area.

  15. Resilience and livelihood dynamics of shrimp farmers and fishers in the Mekong Delta, Vietnam

    OpenAIRE

    Tran Thi Phung, H.

    2012-01-01

    Shrimp aquaculture and fishery, the two important economic sectors in Vietnam, have been promoted by the government to reduce poverty, provide job opportunities, and to increase exports to support economic development. However, this expansion of fishery and aquaculture has also had negative effects. Hundreds of thousands of hectares of mangrove forest have been replaced by shrimp ponds and, as a result, have brought ecological risks like water pollution, causing shrimp disease outbreaks. The...

  16. Combined fluvial and pluvial urban flood hazard analysis: method development and application to Can Tho City, Mekong Delta, Vietnam

    Science.gov (United States)

    Apel, H.; Trepat, O. M.; Hung, N. N.; Chinh, D. T.; Merz, B.; Dung, N. V.

    2015-08-01

    Many urban areas experience both fluvial and pluvial floods, because locations next to rivers are preferred settlement areas, and the predominantly sealed urban surface prevents infiltration and facilitates surface inundation. The latter problem is enhanced in cities with insufficient or non-existent sewer systems. While there are a number of approaches to analyse either fluvial or pluvial flood hazard, studies of combined fluvial and pluvial flood hazard are hardly available. Thus this study aims at the analysis of fluvial and pluvial flood hazard individually, but also at developing a method for the analysis of combined pluvial and fluvial flood hazard. This combined fluvial-pluvial flood hazard analysis is performed taking Can Tho city, the largest city in the Vietnamese part of the Mekong Delta, as example. In this tropical environment the annual monsoon triggered floods of the Mekong River can coincide with heavy local convective precipitation events causing both fluvial and pluvial flooding at the same time. Fluvial flood hazard was estimated with a copula based bivariate extreme value statistic for the gauge Kratie at the upper boundary of the Mekong Delta and a large-scale hydrodynamic model of the Mekong Delta. This provided the boundaries for 2-dimensional hydrodynamic inundation simulation for Can Tho city. Pluvial hazard was estimated by a peak-over-threshold frequency estimation based on local rain gauge data, and a stochastic rain storm generator. Inundation was simulated by a 2-dimensional hydrodynamic model implemented on a Graphical Processor Unit (GPU) for time-efficient flood propagation modelling. All hazards - fluvial, pluvial and combined - were accompanied by an uncertainty estimation considering the natural variability of the flood events. This resulted in probabilistic flood hazard maps showing the maximum inundation depths for a selected set of probabilities of occurrence, with maps showing the expectation (median) and the uncertainty by

  17. Survey of current crop management practices in a mixed-ricefield landscape, Mekong Delta, Vietnam - potential of habitat manipulation for improved control of citrus leafminer and citrus red mite

    NARCIS (Netherlands)

    Mele, van P.; Lenteren, van J.C.

    2002-01-01

    In the Mekong Delta, Vietnam, the citrus leafminer Phyllocnistis citrella (CLM) and the citrus red mite Panonychus citri are major pests in both sweet orange (Citrus sinensis) and Tieu mandarin (C. reticulata). Survey data indicate that these pest problems might be aggravated after farmers have

  18. Environmental comparison of intensive and integrated agriculture-aquaculture systems for striped catfish production in the Mekong Delta, Vietnam, based on two existing case studies using life cycle assessment

    NARCIS (Netherlands)

    Kluts, I.N.; Potting, J.M.B.; Bosma, R.H.; Phong, L.T.; Udo, H.M.J.

    2012-01-01

    Vietnam is the largest producer for the export of striped catfish. Traditionally striped catfish production in the Mekong Delta took place in integrated agriculture–aquaculture systems, but has shifted recently to intensive systems to meet increasing export demands. A recent study quantified the

  19. Barriers to Implementing Irrigation and Drainage Policies in An Giang Province, Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Tran, D.D.; Weger, J.

    2017-01-01

    Water management in delta floodplains worldwide faces many challenges due to the changing climate and increasing human intervention in the hydrological regimes of rivers. Irrigation and drainage systems are necessary components of a water management strategy that aims to support human habitation and

  20. Human factors and tidal influences on water quality of an urban river in Can Tho, a major city of the Mekong Delta, Vietnam.

    Science.gov (United States)

    Ozaki, Hirokazu; Co, Thi Kinh; Le, Anh Kha; Pham, Viet Nu; Nguyen, Van Be; Tarao, Mitsunori; Nguyen, Huu Chiem; Le, Viet Dung; Nguyen, Hieu Trung; Sagehashi, Masaki; Ninomiya-Lim, Sachi; Gomi, Takashi; Hosomi, Masaaki; Takada, Hideshige

    2014-02-01

    In this study, we focused on water quality in an urban canal and the Mekong River in the city of Can Tho, a central municipality of the Mekong Delta region, southern Vietnam. Water temperature, pH, electrical conductivity, BOD5, CODCr, Na(+), Cl(-), NH4 (+)-N, SO4 (2-)-S, NO3 (-)-N, and NO2 (-)-N for both canal and river, and tide level of the urban canal, were monitored once per month from May 2010 to April 2012. The urban canal is subject to severe anthropogenic contamination, owing to poor sewage treatment. In general, water quality in the canal exhibited strong tidal variation, poorer at lower tides and better at higher tides. Some anomalies were observed, with degraded water quality under some high-tide conditions. These were associated with flow from the upstream residential area. Therefore, it was concluded that water quality in the urban canal changed with a balance between dilution effects and extent of contaminant supply, both driven by tidal fluctuations in the Mekong River.

  1. A Model of Clean Water Supply and Improvement of Enviromental Sanitary Conditions in Residential Clusters in The Mekong Delta, Vietnam

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    Chi Nguyen Thuy Lan

    2015-12-01

    Full Text Available In accordance with Decision 99/TTg dated 9/2/1996 and Decision 173/TTg dated 6/11/2001 of the Prime Minister regarding the construction program of residential clusters (residential flood free areas, these residential areas as constructed would be fully equipped with critical infrastructures and services such as water supply and drainage works, toilets with sanitary appropriateness, etc. to ensure environmental sanitary conditions in the residential clusters. However, the actual surveys done in residential clusters in the Mekong Delta show that many arising problems must be addressed to enable the local communities to have better living conditions and ensure the sanitary conditions and environmental safety.

  2. Perceived gender inequality, sexual communication self-efficacy, and sexual behaviour among female undergraduate students in the Mekong Delta of Vietnam

    Science.gov (United States)

    Bui, Thanh Cong; Markham, Christine M.; Ross, Michael W.; Williams, Mark L.; Beasley, R. Palmer; Tran, Ly T. H.; Nguyen, Huong T. H.; Le, Thach Ngoc

    2012-01-01

    Background Worldwide, the literature on sexual behaviour has documented associations between gender-based relationship inequality and sexual communication ability and the actual use of condoms or other contraceptives among young women. This study aimed to examine these associations among undergraduate female students in the Mekong Delta of Vietnam. Methods A cross-sectional survey of 1181 female third-year students from two universities in the Mekong Delta was conducted. Latent variable modelling and logistic regression were employed to examine the hypothesised associations. Results Among the 72.4% of students who had ever had boyfriends, 44.8% indicated that their boyfriends had asked for sex, 13% had had penile–vaginal sex and 10.3% had had oral sex. For those who had had penile–vaginal sex, 33% did not use any contraceptive method, including condoms, during their first sexual intercourse. The greater a student’s perception that women were subordinate to men, the lower her self-efficacy for sexual communication and the lower her actual frequency of discussing safer sex matters and asking her partner to use a condom. Sexual communication self-efficacy was associated with actual contraceptive use (P = 0.039) but only marginally with condom use (P = 0.092) at first sexual intercourse. Conclusion Sexual health promotion strategies should address the influence of gender relations on young women’s sexual communication self-efficacy and the subsequent impact on actual contraceptive and condom use. PMID:22877589

  3. Combined fluvial and pluvial urban flood hazard analysis: concept development and application to Can Tho city, Mekong Delta, Vietnam

    Science.gov (United States)

    Apel, Heiko; Martínez Trepat, Oriol; Nghia Hung, Nguyen; Thi Chinh, Do; Merz, Bruno; Viet Dung, Nguyen

    2016-04-01

    Many urban areas experience both fluvial and pluvial floods, because locations next to rivers are preferred settlement areas and the predominantly sealed urban surface prevents infiltration and facilitates surface inundation. The latter problem is enhanced in cities with insufficient or non-existent sewer systems. While there are a number of approaches to analyse either a fluvial or pluvial flood hazard, studies of a combined fluvial and pluvial flood hazard are hardly available. Thus this study aims to analyse a fluvial and a pluvial flood hazard individually, but also to develop a method for the analysis of a combined pluvial and fluvial flood hazard. This combined fluvial-pluvial flood hazard analysis is performed taking Can Tho city, the largest city in the Vietnamese part of the Mekong Delta, as an example. In this tropical environment the annual monsoon triggered floods of the Mekong River, which can coincide with heavy local convective precipitation events, causing both fluvial and pluvial flooding at the same time. The fluvial flood hazard was estimated with a copula-based bivariate extreme value statistic for the gauge Kratie at the upper boundary of the Mekong Delta and a large-scale hydrodynamic model of the Mekong Delta. This provided the boundaries for 2-dimensional hydrodynamic inundation simulation for Can Tho city. The pluvial hazard was estimated by a peak-over-threshold frequency estimation based on local rain gauge data and a stochastic rainstorm generator. Inundation for all flood scenarios was simulated by a 2-dimensional hydrodynamic model implemented on a Graphics Processing Unit (GPU) for time-efficient flood propagation modelling. The combined fluvial-pluvial flood scenarios were derived by adding rainstorms to the fluvial flood events during the highest fluvial water levels. The probabilities of occurrence of the combined events were determined assuming independence of the two flood types and taking the seasonality and probability of

  4. Theory of Reasoned Action as a Framework for Communicating Climate Risk: A Case Study of Schoolchildren in the Mekong Delta in Vietnam

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    Quynh Anh Nguyen

    2018-06-01

    Full Text Available Communicating climate risks to vulnerable groups motivating them to take adaptive actions remains a significant challenge in many populations, especially to children. The theory of reasoned action (TRA suggests that attitude and subjective norms are important for persuasive communication. This study assesses how to apply TRA, its constructs and other relevant factors to predict behavior intention and beliefs and to change behavior tendency. The randomized field experiment method was applied to explore the differences between pre- and post-communication treatments (2 × 2 design. Can Tho city, located in the Mekong Delta of Vietnam, was selected as the research context because of its vulnerability to climate change. The results show that, first, TRA was found to be a significant predictor model of children’s climate change behavior intentions. Second, attitude has a significant effect on the children’s intention to act while videos with subjective norm treatment had not. The treatment interaction of both constructs also had a significant effect. Third, TRA theory-based treatments are positively associated with changes in children’ salient beliefs on attitude and normative belief on social norm toward climate change. In addition, past practices, knowledge and gender are further factors that influence children’s behavior intentions. A theory-inspired design of communication strategy allows the prediction and influencing of intentions. This finding has strong implications for both research and development in Vietnam.

  5. A Decision Tree Analysis to Support Potential Climate Change Adaptations of Striped Catfish (Pangasianodon hypophthalmus Sauvage) Farming in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Nguyen, L.A.; Verreth, J.A.J.; Leemans, H.B.J.; Bosma, R.H.; Silva, De S.

    2016-01-01

    This study uses the decision tree framework to analyse possible climate change impact adaptation options for pangasius (Pangasianodon hypopthalmus Sauvage) farming in the Mekong Delta. Here we present the risks for impacts and the farmers' autonomous and planned public adaptation by using primary

  6. Earthworms of the 'acaecate' Pheretima group in Vietnam (Oligochaeta: Megascolecidae), with description of a new species from the Mekong delta.

    Science.gov (United States)

    Nguyen, Tung T; Tran, Binh T T; Nguyen, Anh D

    2014-09-22

    The 'acaecate' Pheretima group from Vietnam is revised, with description of a new species, Polypheretima mekongmontis sp. nov. A total of 18 species of three genera, Metapheretima Michaelsen, 1928, Planapheretima Michaelsen, 1934, and Polypheretima Michaelsen, 1934 has been recorded from Vietnam. Caecate species of Planapheretima are included here as well. Planapheretima arboricola (Rosa, 1890), Pl. lacertina (Chen, 1946), Pl. tenebrica (Chen, 1946), Polypheretima elongata (Perrier, 1872), and Po. taprobanae (Beddard, 1892) are originally recorded from other countries; all remaining species are native to Vietnam. The species Polypheretima tani (Thai, 1996) and Po. tiencanhensis (Pham, 1995) are transferred to the genus Metapheretima. A key to species and distribution maps are also presented.

  7. Temporal and spatial assessment of river surface water quality using multivariate statistical techniques: a study in Can Tho City, a Mekong Delta area, Vietnam.

    Science.gov (United States)

    Phung, Dung; Huang, Cunrui; Rutherford, Shannon; Dwirahmadi, Febi; Chu, Cordia; Wang, Xiaoming; Nguyen, Minh; Nguyen, Nga Huy; Do, Cuong Manh; Nguyen, Trung Hieu; Dinh, Tuan Anh Diep

    2015-05-01

    The present study is an evaluation of temporal/spatial variations of surface water quality using multivariate statistical techniques, comprising cluster analysis (CA), principal component analysis (PCA), factor analysis (FA) and discriminant analysis (DA). Eleven water quality parameters were monitored at 38 different sites in Can Tho City, a Mekong Delta area of Vietnam from 2008 to 2012. Hierarchical cluster analysis grouped the 38 sampling sites into three clusters, representing mixed urban-rural areas, agricultural areas and industrial zone. FA/PCA resulted in three latent factors for the entire research location, three for cluster 1, four for cluster 2, and four for cluster 3 explaining 60, 60.2, 80.9, and 70% of the total variance in the respective water quality. The varifactors from FA indicated that the parameters responsible for water quality variations are related to erosion from disturbed land or inflow of effluent from sewage plants and industry, discharges from wastewater treatment plants and domestic wastewater, agricultural activities and industrial effluents, and contamination by sewage waste with faecal coliform bacteria through sewer and septic systems. Discriminant analysis (DA) revealed that nephelometric turbidity units (NTU), chemical oxygen demand (COD) and NH₃ are the discriminating parameters in space, affording 67% correct assignation in spatial analysis; pH and NO₂ are the discriminating parameters according to season, assigning approximately 60% of cases correctly. The findings suggest a possible revised sampling strategy that can reduce the number of sampling sites and the indicator parameters responsible for large variations in water quality. This study demonstrates the usefulness of multivariate statistical techniques for evaluation of temporal/spatial variations in water quality assessment and management.

  8. Evaluating sustainable adaptation strategies for vulnerable mega-deltas using system dynamics modelling: Rice agriculture in the Mekong Delta's An Giang Province, Vietnam.

    Science.gov (United States)

    Chapman, Alexander; Darby, Stephen

    2016-07-15

    Challenging dynamics are unfolding in social-ecological systems around the globe as society attempts to mitigate and adapt to climate change while sustaining rapid local development. The IPCC's 5th assessment suggests these changing systems are susceptible to unforeseen and dangerous 'emergent risks'. An archetypal example is the Vietnamese Mekong Delta (VMD) where the river dyke network has been heightened and extended over the last decade with the dual objectives of (1) adapting the delta's 18 million inhabitants and their livelihoods to increasingly intense river-flooding, and (2) developing rice production through a shift from double to triple-cropping. Negative impacts have been associated with this shift, particularly in relation to its exclusion of fluvial sediment deposition from the floodplain. A deficit in our understanding of the dynamics of the rice-sediment system, which involve unintuitive delays, feedbacks, and tipping points, is addressed here, using a system dynamics (SD) approach to inform sustainable adaptation strategies. Specifically, we develop and test a new SD model which simulates the dynamics between the farmers' economic system and their rice agriculture operations, and uniquely, integrates the role of fluvial sediment deposition within their dyke compartment. We use the model to explore a range of alternative rice cultivation strategies. Our results suggest that the current dominant strategy (triple-cropping) is only optimal for wealthier groups within society and over the short-term (ca. 10years post-implementation). The model suggests that the policy of opening sluice gates and leaving paddies fallow during high-flood years, in order to encourage natural sediment deposition and the nutrient replenishment it supplies, is both a more equitable and a more sustainable policy. But, even with this approach, diminished supplies of sediment-bound nutrients and the consequent need to compensate with artificial fertilisers will mean that smaller

  9. Managing flood risks in the Mekong Delta

    NARCIS (Netherlands)

    Hoang, Long Phi; Biesbroek, Robbert; Tri, Van Pham Dang; Kummu, Matti; Vliet, van Michelle T.H.; Leemans, Rik; Kabat, Pavel; Ludwig, Fulco

    2018-01-01

    Climate change and accelerating socioeconomic developments increasingly challenge flood-risk management in the Vietnamese Mekong River Delta—a typical large, economically dynamic and highly vulnerable delta. This study identifies and addresses the emerging challenges for flood-risk management.

  10. An agro-ecological evaluation of aquaculture integration into farming systems of the Mekong Delta

    NARCIS (Netherlands)

    Phong, L.T.; Dam, van A.A.; Udo, H.M.J.; Mensvoort, van M.E.F.; Tri, L.Q.; Steenstra, F.A.; Zijpp, van der A.J.

    2010-01-01

    This study compared ecological sustainability of Integrated Agriculture-Aquaculture (IAA) systems with different forms and intensity of aquaculture integration in the Mekong Delta of Vietnam: orchard-based and low-input fish (O-LF); rice-based and medium-input fish (R-MF); and rice-based and

  11. Losing ground in mega-deltas: basin-scale response to existential threats to the Mekong Delta

    Science.gov (United States)

    Arias, M. E.; Kondolf, G. M.; Schmitt, R. J. P.; Carling, P. A.; Darby, S. E.; Bizzi, S.; Castelletti, A.; Cochrane, T. A.; Gibson, S.; Kummu, M.; Oeurng, C.; Rubin, Z.; Wild, T. B.

    2017-12-01

    The Mekong Delta is, in terms of the number of livelihoods it supports, its economic importance, and in its vulnerability to climate change and sinking lands, one of the world's critically threatened mega-deltas. Livelihoods depend on the mere existence of the delta, but also on ecosystem services provided by the delta's drainage basin spanning 795,000 km2 in six abutting countries. These ecosystem services include delivery of sand required to build delta land in the face of rising sea-levels and sediment bound nutrients, provision of spawning habitat for fish that are ultimately harvested in the delta, and hydrologic regulation driving the delta's unique flood-pulse regime. However, while the delta is mainly located in Vietnam, the basin of the Mekong River is shared among China, Myanmar, Laos, Thailand, Cambodia, and Vietnam. In the context of the region's dynamic growth, individual countries are pushing their own development agendas, which include extensive dam building, in-channel sand mining, construction of dykes and canals, and groundwater pumping, all of which contribute to subsidence and erosion of the Delta. Our synthesis of recent research indicates that most of the Mekong's delta land will likely fall below sea-level by 2100 as result of these drivers, exacerbating the impacts of global climatic changes. In this context, local infrastructural projects and changes in land- and water-management may temporarily mitigate some negative effects, but do not address the existential threat to the delta as a whole. To prevent, or at least substantially postpone, the drowning of the Mekong Delta requires identification of the key drivers and immediate concerted management actions on the basin-scale to change the trajectory of subsidence and sediment deficit. A specific challenge is to find the institutional arrangements in this transnational context that could support the needed management changes and equitably distribute costs and impacts. The Mekong Delta is

  12. Coordination and health sector adaptation to climate change in the Vietnamese Mekong Delta

    Directory of Open Access Journals (Sweden)

    Daniel Gilfillan

    2017-09-01

    Full Text Available This research examines the impact of three coordination dimensions on health sector adaptation to climate change in the Vietnamese Mekong Delta: cross-scale, cross-sectoral, and cross-boundary. While tasks are divided up between government ministries and departments in Vietnam, there is little collaboration on issues that span mandates. Similarly, while water flows in the Vietnamese Mekong Delta take resource management and health concerns across provincial boundaries, formal mechanisms for interprovincial collaboration are lacking. While decentralization efforts have sought to devolve authority and decision making to lower levels, there is continued state-centered top-down policy making, and this limits collaborative coordination across scales. All three of these issues inhibit health sector adaptation to climate change in the Vietnamese Mekong Delta, and though these coordination issues are recognized by the Vietnamese government, to date there has been little success in addressing them. The authors hope to stimulate further debate and discussion of coordination problems, and conclude that despite some significant challenges, the South West Steering Committee could play a facilitating role coordinating climate change responses in health and other sectors across the Vietnamese Mekong Delta. As an analysis of governance, this research is applicable to other areas and sectors in Vietnam, as well as to other parts of South East Asia.

  13. A climate-based prediction model in the high-risk clusters of the Mekong Delta region, Vietnam: towards improving dengue prevention and control.

    Science.gov (United States)

    Phung, Dung; Talukder, Mohammad Radwanur Rahman; Rutherford, Shannon; Chu, Cordia

    2016-10-01

    To develop a prediction score scheme useful for prevention practitioners and authorities to implement dengue preparedness and controls in the Mekong Delta region (MDR). We applied a spatial scan statistic to identify high-risk dengue clusters in the MDR and used generalised linear-distributed lag models to examine climate-dengue associations using dengue case records and meteorological data from 2003 to 2013. The significant predictors were collapsed into categorical scales, and the β-coefficients of predictors were converted to prediction scores. The score scheme was validated for predicting dengue outbreaks using ROC analysis. The north-eastern MDR was identified as the high-risk cluster. A 1 °C increase in temperature at lag 1-4 and 5-8 weeks increased the dengue risk 11% (95% CI, 9-13) and 7% (95% CI, 6-8), respectively. A 1% rise in humidity increased dengue risk 0.9% (95% CI, 0.2-1.4) at lag 1-4 and 0.8% (95% CI, 0.2-1.4) at lag 5-8 weeks. Similarly, a 1-mm increase in rainfall increased dengue risk 0.1% (95% CI, 0.05-0.16) at lag 1-4 and 0.11% (95% CI, 0.07-0.16) at lag 5-8 weeks. The predicted scores performed with high accuracy in diagnosing the dengue outbreaks (96.3%). This study demonstrates the potential usefulness of a dengue prediction score scheme derived from complex statistical models for high-risk dengue clusters. We recommend a further study to examine the possibility of incorporating such a score scheme into the dengue early warning system in similar climate settings. © 2016 John Wiley & Sons Ltd.

  14. Dimensions of gender relations and reproductive health inequity perceived by female undergraduate students in the Mekong Delta of Vietnam: a qualitative exploration

    Directory of Open Access Journals (Sweden)

    Bui Thanh

    2012-10-01

    Full Text Available Abstract Introduction Increasing evidence indicates that gender equity has a significant influence on women’s health; yet few culturally specific indicators of gender relations exist which are applicable to health. This study explores dimensions of gender relations perceived by female undergraduate students in southern Vietnamese culture, and qualitatively examines how this perceived gender inequity may influence females’ sexual or reproductive health. Methods Sixty-two female undergraduate students from two universities participated in eight focus group discussions to talk about their perspectives regarding national and local gender equity issues. Results Although overall gender gaps in the Mekong Delta were perceived to have decreased in comparison to previous times, several specific dimensions of gender relations were emergent in students’ discussions. Perceived dimensions of gender relations were comparable to theoretical structures of the Theory of Gender and Power, and to findings from several reports describing the actual inferiority of women. Allocation of housework and social paid work represented salient dimensions of labor. The most salient dimension of power related to women in positions of authority. Salient dimensions of cathexis related to son preference, women’s vulnerability to blame or criticism, and double standards or expectations. Findings also suggested that gender inequity potentially influenced women’s sexual and reproductive health as regards to health information seeking, gynecological care access, contraceptive use responsibility, and child bearing. Conclusion Further investigations of the associations between gender relations and different women’s sexual and reproductive health outcomes in this region are needed. It may be important to address gender relations as a distal determinant in health interventions in order to promote gender-based equity in sexual and reproductive health.

  15. Dimensions of gender relations and reproductive health inequity perceived by female undergraduate students in the Mekong Delta of Vietnam: a qualitative exploration.

    Science.gov (United States)

    Bui, Thanh Cong; Markham, Christine M; Ross, Michael W; Williams, Mark L; Beasley, R Palmer; Tran, Ly T H; Nguyen, Huong T H; Le, Thach Ngoc

    2012-10-24

    Increasing evidence indicates that gender equity has a significant influence on women's health; yet few culturally specific indicators of gender relations exist which are applicable to health. This study explores dimensions of gender relations perceived by female undergraduate students in southern Vietnamese culture, and qualitatively examines how this perceived gender inequity may influence females' sexual or reproductive health. Sixty-two female undergraduate students from two universities participated in eight focus group discussions to talk about their perspectives regarding national and local gender equity issues. Although overall gender gaps in the Mekong Delta were perceived to have decreased in comparison to previous times, several specific dimensions of gender relations were emergent in students' discussions. Perceived dimensions of gender relations were comparable to theoretical structures of the Theory of Gender and Power, and to findings from several reports describing the actual inferiority of women. Allocation of housework and social paid work represented salient dimensions of labor. The most salient dimension of power related to women in positions of authority. Salient dimensions of cathexis related to son preference, women's vulnerability to blame or criticism, and double standards or expectations. Findings also suggested that gender inequity potentially influenced women's sexual and reproductive health as regards to health information seeking, gynecological care access, contraceptive use responsibility, and child bearing. Further investigations of the associations between gender relations and different women's sexual and reproductive health outcomes in this region are needed. It may be important to address gender relations as a distal determinant in health interventions in order to promote gender-based equity in sexual and reproductive health.

  16. Success factors for sustainable private business operation of decentralised rural electrification with PV - Results from the project "DELTA PRO RES" in the lower Delta Mekong countries

    OpenAIRE

    Gölz, S.; Vogt, G.; Maigne, Y.; Mozas, K.

    2006-01-01

    The project Delta PRO RES is the response to the wave of electricity sector reform in developing countries in South East Asia which provides opportunities for a new approach: bankable rural electrification. The project prepares the ground for this future track by developing a methodology and markets to increase rural access to energy with decentralized renewable energy systems in the Lower Delta Mekong countries Vietnam, Cambodia and Lao PDR. Private entrepreneurship and venture capital inves...

  17. Learning Environment in Vietnamese Physics Teacher Education Programme through the Lens of Constructivism: A Case Study of a State University in Mekong Delta Region, Vietnam

    Science.gov (United States)

    Thao-Do, Thi Phuong; Bac-Ly, Dang Thi; Yuenyong, Chokchai

    2016-01-01

    Constructivism was introduced to Vietnam through many ways such as workshops, books, the Internet, and so on. However, due to the lack of professional education, fundamental ideas of constructivist learning perhaps were missing or neglected through classroom activities. Furthermore, due to the influence of culture and society, Vietnamese…

  18. Questioning triple rice intensification on the Vietnamese mekong delta floodplains

    NARCIS (Netherlands)

    Tran, Dung Duc; Halsema, van Gerardo; Hellegers, Petra J.G.J.; Ludwig, Fulco; Wyatt, Andrew

    2018-01-01

    Large areas of the Vietnamese Mekong Delta floodplains (VMDF) are protected by high dikes to facilitate three rice crops per year. While this has increased rice production, there is evidence that triple rice systems have negative long-term effects, both environmental and economic. Double rice

  19. Clustering of Beijing genotype Mycobacterium tuberculosis isolates from the Mekong delta in Vietnam on the basis of variable number of tandem repeat versus restriction fragment length polymorphism typing

    Directory of Open Access Journals (Sweden)

    Huyen Mai NT

    2013-02-01

    Full Text Available Abstract Background In comparison to restriction fragment length polymorphism (RFLP typing, variable number of tandem repeat (VNTR typing is easier to perform, faster and yields results in a simple, numerical format. Therefore, this technique has gained recognition as the new international gold standard in typing of Mycobacterium tuberculosis. However, some reports indicated that VNTR typing may be less suitable for Beijing genotype isolates. We therefore compared the performance of internationally standardized RFLP and 24 loci VNTR typing to discriminate among 100 Beijing genotype isolates from the Southern Vietnam. Methods Hundred Beijing genotype strains defined by spoligotyping were randomly selected and typed by RFLP and VNTR typing. The discriminatory power of VNTR and RFLP typing was compared using the Bionumerics software. Results Among 95 Beijing strains available for analysis, 14 clusters were identified comprising 34 strains and 61 unique profiles in 24 loci VNTR typing ((Hunter Gaston Discrimination Index (HGDI = 0.994. 13 clusters containing 31 strains and 64 unique patterns in RFLP typing (HGDI = 0.994 were found. Nine RFLP clusters were subdivided by VNTR typing and 12 VNTR clusters were split by RFLP. Five isolates (5% revealing double alleles or no signal in two or more loci in VNTR typing could not be analyzed. Conclusions Overall, 24 loci VNTR typing and RFLP typing had similar high-level of discrimination among 95 Beijing strains from Southern Vietnam. However, loci VNTR 154, VNTR 2461 and VNTR 3171 had hardly added any value to the level of discrimination.

  20. Soil knowledge for farmers, farmer knowledge for soil scientists : the case of acid sulphate soils in the Mekong delta, Viet Nam

    NARCIS (Netherlands)

    Mensvoort, van M.E.F.

    1996-01-01


    Half the Mekong delta in Vietnam, i.e. around 2 million hectares, suffers soil related problems due to acid sulphate soils. These soils generate sulphuric acid due to the oxidation of pyrite after aeration. Pyrite is most easily formed in tidal swamps. Human interference through land

  1. Integrated soil and water management in acid sulphate soils : balancing agricultural production and environmental requirements in the Mekong Delta, Viet Nam

    NARCIS (Netherlands)

    Le, Q.M.

    1996-01-01


    The objectives of this study in the Mekong delta, Vietnam, were: (1) to obtain a better understanding of the effects of soil physical properties and flow types on solute transport in ASS emphasing aluminum; (2) to quantify environmental hazards resulting from amelioration activities in

  2. Challenges, Approaches and Experiences from Asian Deltas and the Rhine-Meuse Delta : Regional Training Workshop on Delta Planning and Management

    NARCIS (Netherlands)

    Wosten, J.H.M.; Douven, W.; Long Phi, H.; Fida Abdullah Khan, M.

    2013-01-01

    River delta's, like the Mekong Delta (Vietnam), Ganges-Brahmaputra Delta (Bangladesh), Ayeyarwady Delta (Myanmar), Nile (Egypt) and Ciliwung Delta (Indonesia) are developing rapidly and are characterised by large-scale urbanisation and industrialization processes. They are facing serious planning

  3. Flood Mapping and Flood Dynamics of the Mekong Delta: ENVISAT-ASAR-WSM Based Time Series Analyses

    Directory of Open Access Journals (Sweden)

    Stefan Dech

    2013-02-01

    Full Text Available Satellite remote sensing is a valuable tool for monitoring flooding. Microwave sensors are especially appropriate instruments, as they allow the differentiation of inundated from non-inundated areas, regardless of levels of solar illumination or frequency of cloud cover in regions experiencing substantial rainy seasons. In the current study we present the longest synthetic aperture radar-based time series of flood and inundation information derived for the Mekong Delta that has been analyzed for this region so far. We employed overall 60 Envisat ASAR Wide Swath Mode data sets at a spatial resolution of 150 meters acquired during the years 2007–2011 to facilitate a thorough understanding of the flood regime in the Mekong Delta. The Mekong Delta in southern Vietnam comprises 13 provinces and is home to 18 million inhabitants. Extreme dry seasons from late December to May and wet seasons from June to December characterize people’s rural life. In this study, we show which areas of the delta are frequently affected by floods and which regions remain dry all year round. Furthermore, we present which areas are flooded at which frequency and elucidate the patterns of flood progression over the course of the rainy season. In this context, we also examine the impact of dykes on floodwater emergence and assess the relationship between retrieved flood occurrence patterns and land use. In addition, the advantages and shortcomings of ENVISAT ASAR-WSM based flood mapping are discussed. The results contribute to a comprehensive understanding of Mekong Delta flood dynamics in an environment where the flow regime is influenced by the Mekong River, overland water-flow, anthropogenic floodwater control, as well as the tides.

  4. Changes in Ecosystem Services and related Livelihoods in the Mekong Delta: vulnerabilities and adaptation strategies

    Science.gov (United States)

    Sebesvari, Z.; Renaud, F. G.

    2014-12-01

    The Mekong Delta (Vietnam) is highly vulnerable to the many impacts of global environmental change as well as to the accelerating anthropogenic changes in the catchment and in the delta itself. Today the delta is an agricultural landscape controlled by engineering structures such as channels, dykes, embankments, and sluice gates. These structures have been constructed gradually over the last 200 years mainly for irrigation and flood control in the upper part of the delta and to control saline intrusion in the coastal areas. Recent changes in the hydrology mainly driven by upstream hydropower development on the mainstream and the tributaries of the Mekong will likely have far reaching impacts on the delta´s social-ecological systems through changes in e.g. sedimentation processes, nutrient transport as well as the health of aquatic ecosystems. Further threats to the delta include sea level rise and an increase in seasonal rainfall variability leading to an increase in flood variability. These changes affect the lives of millions of low-income inhabitants who depend on the ecosystem services provided by the Mekong for their livelihoods and sustenance. Since the changes in ecosystem service provision are occurring relatively fast while the resource dependency of the delta population is very high, adaptation becomes a challenge. An assessment of livelihood dependencies on ecosystem services requires an understanding of ecosystem services affected by different drivers of change, as well as of the types of livelihoods likely to be jeopardized as a result of these changes. We will present main ecosystem services supporting specific livelihoods, discuss how they are threatened, and analyse the merits of potential solutions. Options based solely on grey infrastructure might be problematic on the long term while an integration of ecosystem based solution such as a (re)adaptation of agricultural production systems to floods in the upper delta might be a more sustainable

  5. Dynamics of sustainability in integrated agriculture : aquaculture systems in the Mekong Delta

    NARCIS (Netherlands)

    Phong, L.T.

    2010-01-01

    Key words: Mekong Delta; IAA; ECOPATH; Nutmon; LCA; environmental impact; sustainability

    In the Mekong Delta (MD), intensification and modernization of crop, fish and livestock production causes concern about sustainable use of natural resources. The objectives of this research were to

  6. Quantifying suspended sediment dynamics in mega deltas using remote sensing data: A case study of the Mekong floodplains

    Science.gov (United States)

    Dang, Thanh Duc; Cochrane, Thomas A.; Arias, Mauricio E.

    2018-06-01

    Temporal and spatial concentrations of suspended sediment in floodplains are difficult to quantify because in situ measurements can be logistically complex, time consuming and costly. In this research, satellite imagery with long temporal and large spatial coverage (Landsat TM/ETM+) was used to complement in situ suspended sediment measurements to reflect sediment dynamics in a large (70,000 km2) floodplain. Instead of using a single spectral band from Landsat, a Principal Component Analysis was applied to obtain uncorrelated reflectance values for five bands of Landsat TM/ETM+. Significant correlations between the scores of the 1st principal component and the values of continuously gauged suspended sediment concentration, shown via high coefficients of determination of sediment rating curves (R2 ranging from 0.66 to 0.92), permit the application of satellite images to quantify spatial and temporal sediment variation in the Mekong floodplains. Estimated suspended sediment maps show that hydraulic regimes at Chaktomuk (Cambodia), where the Mekong, Bassac, and Tonle Sap rivers diverge, determine the amount of seasonal sediment supplies to the Mekong Delta. The development of flood prevention systems to allow for three rice crops a year in the Vietnam Mekong Delta significantly reduces localized flooding, but also prevents sediment (source of nutrients) from entering fields. A direct consequence of this is the need to apply more artificial fertilizers to boost agricultural productivity, which may trigger environmental problems. Overall, remote sensing is shown to be an effective tool to understand temporal and spatial sediment dynamics in large floodplains.

  7. Erosion of the Mekong delta: the role of human activities

    Science.gov (United States)

    Anthony, E.; Dussouillez, P.; Goichot, M.; Brunier, G.; Dolique, F.; Nguyen, V.; Loisel, H.; Mangin, A.; Vantrepotte, V.

    2013-12-01

    River deltas are threatened by dams, dykes, flow channelling, and aggregate extraction. These activities outweigh climate change and sea-level rise in causing delta vulnerability1, and will aggravate the impacts to be expected from these effects2. We show here from analysis of: (1) delta channel morphology and sediment budgets, and (2) satellite imagery, that the Mekong delta, considered as the world's third largest, and hitherto strongly prograding, is now in a phase of large-scale erosion. We discuss the mechanistic links involved in erosion and the way these are related to human activities. High-resolution (2.5 m) SPOT 5 images for the years 2003, 2007, 2011/12 covering 405 km of the delta shoreline show an overall retreat rate of over 8 m a year. 75% of the analysed shoreline, i.e., the muddy western sector, is now retreating at rates exceeding 50 m a year in places. The sandy river-mouth sector maintains a semblance of stability, but with strong variations. We attribute erosion to a cascade of morphosedimentary changes linked to sediment mining from the deltaic channels and upstream dam interception. We estimated from Meris satellite imagery an annual 5% decrease in surface suspended concentrations exiting at the mouths of the Mekong over the period 2003-2011 that may reflect increased trapping of mud behind dams in China. We also infer modification of river-mouth and coastal mud storage patterns resulting from a loss of ca. 200 million m3 of delta channel sediments between 1998 and 2008 from aggregate extraction. Dykes have been shown to result in increased channel flow velocities during the high-discharge monsoon season, favouring further channel deepening3. Stronger river-mouth outflow velocities during this season may be leading to export of a greater proportion of mud far offshore of the coastal longshore transport corridor that ensured mud supply to, and past progradation of, the muddy western coast. In contrast, greater seawater penetration in the

  8. Carbon dynamics and CO2 and CH4 outgassing in the Mekong delta

    Science.gov (United States)

    Borges, Alberto V.; Abril, Gwenaël; Bouillon, Steven

    2018-02-01

    We report a data set of biogeochemical variables related to carbon cycling obtained in the three branches (Mỹ Tho, Hàm Luông, Cố Chiên) of the Mekong delta (Bến Tre province, Vietnam) in December 2003, April 2004, and October 2004. Both the inner estuary (upstream of the mouth) and the outer estuary (river plume) were sampled, as well as side channels. The values of the partial pressure of CO2 (pCO2) ranged between 232 and 4085 ppm, O2 saturation level (%O2) between 63 and 114 %, and CH4 between 2 and 2217 nmol L-1, within the ranges of values previously reported in temperate and tropical meso- and macro-tidal estuaries. Strong seasonal variations were observed. In the upper oligohaline estuary, low pCO2 (479-753 ppm) and high %O2 (98-106 %) values were observed in April 2004 most probably related to freshwater phytoplankton growth owing to low freshwater discharge (1400 m3 s-1) and increase in water residence time; during the two other sampling periods with a higher freshwater discharge (9300-17 900 m3 s-1), higher pCO2 (1895-2664 ppm) and lower %O2 (69-84 %) values were observed in the oligohaline part of the estuary. In October 2004, important phytoplankton growth occurred in the offshore part of the river plume as attested by changes in the contribution of particulate organic carbon (POC) to total suspended matter (TSM) (%POC) and the stable isotope composition of POC (δ13C-POC), possibly related to low TSM values (improvement of light conditions for phytoplankton development), leading to low pCO2 (232 ppm) and high %O2 (114 %) values. Water in the side channels in the Mekong delta was strongly impacted by inputs from the extensive shrimp farming ponds. The values of pCO2, CH4, %O2, and the stable isotope composition of dissolved inorganic carbon (δ13C-DIC) indicated intense organic matter degradation that was partly mediated by sulfate reduction in sediments, as revealed by the slope of total alkalinity (TA) and DIC covariations. The δ13C

  9. Groundwater salinity study in the Mekong Delta using isotope techniques

    International Nuclear Information System (INIS)

    Le Van Khoi, Nguyen Kien Chinh; Do Tien Hung

    2002-01-01

    Environmental isotopes D, 18 O and chemical composition were used for study of recharge and salinization of groundwater in the are located between Bassac and Mekong Rivers. The results showed that: (a) Pleistocene aquifers are recharged through flood plains and outcrops located at the same altitude. The sanility of groundwater in these aquifers is mostly due to dissolution of the aquifer material, (b) Pliocene and Miocene aquifers receive recharge through outcrops located at the higher altitude on the northeast extension of the Delta and Cambodia. The salinity of groundwater in the coastal region of the aquifer is attributable to sea water intrusion. There appears to be significant retention of sea water in the coastal sediment during intrusion. (Author)

  10. Monitoring and modeling the fate of commonly used pesticides in surface water of the Lower Mekong Delta

    Science.gov (United States)

    van Toan, Pham; Sebesvari, Zita; Loan, Vo Phuong Hong; Renaud, Fabrice

    2010-05-01

    , Vietnam. Marine Pollution Bulletin 56, 1476-1485. Dasgupta S., Meisner C., Wheeler D., Nhan L. T., Khuc X., 2005. Pesticide poisoning of farm workers: implications of blood test results from Vietnam. World Bank Policy Research Working Paper 3624. Dung, N.H., Dung, T.T., 2003. Economic and health consequences of pesticide use in paddy production in the Mekong Delta, Vietnam. Economy and environment case studies in Vietnam. Economy and environment program for Southeast Asia. Margni, M., Rossier, D., Crettaz, P., Jolliet, O., 2002. Life cycle impact assessment of pesticides on human health and ecosystems. Agriculture, Ecosystems and Environment 93, 379-392. Mekong River Committee Secretariat (MRCS), 2007. Environmental health concerns related to agro-chemical use in the Mekong Delta. Environment training case studies. Minh, N. H., Minh, T. B., Kajiwara, N., Kunisue, T., Iwata, H., Viet P.H., Tu, N. P. C., Tuyen, B. C., Tanabe, S., 2007. Pollution sources and occurrences of selected persistent organic pollutants (POPs) in sediments of the Mekong River delta, South Vietnam. Chemosphere. 67, 1794-1801. Phuong, D. M., Gopalakrishnan, C., 2003. An application of the contingent valuation method to estimate the loss of value of water resources due to pesticide contamination: the case of the Mekong Delta, Vietnam',International. Journal of Water Resources Development,19, 617-633.

  11. Isotope Compositions Of Mekong River Flow Water In The South Of Vietnam

    International Nuclear Information System (INIS)

    Nguyen Kien Chinh; Huynh Long; Le Danh Chuan; Nguyen Van Nhien; Tran Thi Bich Lien

    2008-01-01

    As a part of the Research Contract No. VIE/12569, isotope composition of Mekong river flow water in the South of Vietnam has been monitored to provide information on water origin and residence times, surface-groundwater exchange in the monitoring area. According to the primary results obtained, a seasonal variation as well as the dependence on local precipitation and on the river water level of isotopic composition of two distributaries of Mekong river water have been observed. At the same time a slight change on season of tritium in rivers water and the difference between tritium content in local rainy water and river water has been recorded. (author)

  12. Biogas Production from Local Biomass Feedstock in the Mekong Delta and Its Utilization for a Direct Internal Reforming Solid Oxide Fuel Cell

    Directory of Open Access Journals (Sweden)

    Yusuke Shiratori

    2017-05-01

    Full Text Available Fuel-flexible solid oxide fuel cell (SOFC technologies are presently under study in a Vietnam-Japan international joint research project. The purpose of this project is to develop and demonstrate an SOFC-incorporated energy circulation system for the sustainable development of the Mekong Delta region. Lab-scale methane fermentation experiments in this study with a mixture of biomass feedstock collected in the Mekong Delta (shrimp pond sludge, bagasse, and molasses from sugar production recorded biogas production yield over 400 L kgVS−1 with H2S concentration below 50 ppm level. This real biogas was directly supplied to an SOFC without any fuel processing such as desulfurization, methane enrichment and pre-reforming, and stable power generation was achieved by applying paper-structured catalyst (PSC technology.

  13. Low Carbon Rice Farming Practices in the Mekong Delta Yield Significantly Higher Profits and Lower Greenhouse Gas Emissions

    Science.gov (United States)

    Rudek, J.; Van Sanh, N.; Tinh, T. K.; Tin, H. Q.; Thu Ha, T.; Pha, D. N.; Cui, T. Q.; Tin, N. H.; Son, N. N.; Thanh, H. H.; Kien, H. T.; Kritee, K.; Ahuja, R.

    2014-12-01

    The Vietnam Low-Carbon Rice Project (VLCRP) seeks to significantly reduce GHG emissions from rice cultivation, an activity responsible for more than 30% of Vietnam's overall GHG emissions, while improving livelihoods for the rice farmer community by decreasing costs and enhancing yield as well as providing supplemental farmer income through the sale of carbon credits. The Mekong Delta makes up 12% of Vietnam's land area, but produces more than 50% of the country's rice, including more than 90% of the rice for export. Rice cultivation is the main source of income for 80% of farmers in the Mekong Delta. VLCRP was launched in late 2012 in the Mekong Delta in two major rice production provinces, Kien Giang and An Giang. To date, VLCRP has completed 11 crop seasons (in Kien Giang and An Giang combined), training over 400 farmer households in applying VLCRP's package of practices (known as 1 Must - 6 Reductions) and building technical capacity to its key stakeholders and rice farmer community leaders. By adopting the 1 Must- 6 Reductions practices (including reduced seeding density, reduced fertilizer and pesticide application, and alternative wetting and drying water management), rice farmers reduce their input costs while maintaining or improving yields, and decreasing greenhouse gas emissions. The VLCRP package of practices also deliver other environmental and social co-benefits, such as reduced water pollution, improved habitat for fishery resources and reduced health risks for farmers through the reduction of agri-chemicals. VLCRP farmers use significantly less inputs (50% reduction in seed, 30% reduction in fertilizer, 40-50% reduction in water) while improving yields 5-10%, leading to an increase in profit from 10% to as high as 60% per hectare. Preliminary results indicate that the 1 Must- 6 Reductions practices have led to approximately 40-65% reductions in greenhouse gas emissions, equivalent to 4 tons of CO2e/ha/yr in An Giang and 35 tons of CO2e/ha/yr in Kien

  14. Governance conditions for adaptive freshwater management in the Vietnamese Mekong Delta

    Science.gov (United States)

    Ha, T. P.; Dieperink, Carel; Dang Tri, Van Pham; Otter, Henriëtte S.; Hoekstra, Piet

    2018-02-01

    The Vietnamese Mekong Delta (VMD) is a region of utmost importance to Vietnam's national food security. However, the availability of required freshwater resources (from both surface and groundwater sources) is currently under great threats due to dry season salinity intrusion, surface water pollution, and over-exploitation of groundwater. Global climate change, sea level rise, and upstream and in situ development activities may worsen the situation. Assuming that adaptive management could be a promising strategy to address the increasingly complex and unpredictable water-related problems in the VMD, we design and apply a framework to identify the extent to which the governance regime in this region exhibits conditions that are likely to promote adaptive freshwater management. Using both primary and secondary data, our analysis reveals that the prospects for adaptive water management in the study area are limited since several conditions were not present. We observe among others limitations in vertical and horizontal integration and public participation, restraints in knowledge and information sharing, inadequate policy development and implementation, and insufficient diversification of financial resources. Following our findings, we conclude the paper with recommendations both for national, regional and local policy interventions and for future research.

  15. Flood precautionary behaviour of private households in Can Tho city in the Mekong Delta

    Science.gov (United States)

    Kreibich, Heidi; Gani Adnan, Sarfaraz; Thi Chinh, Do; Bubeck, Philip

    2015-04-01

    Flood risk is high and it is projected to increase in many places due to the effects of climate change and the on-going intensification of human activities in risk-prone areas. These projections and the considerable uncertainties associated with these developments increasingly require integrated approaches in flood risk management. In addition to flood protection, private precautionary measures aim at reducing the potential negative consequences of floods. Thus, insights into flood precautionary behaviour are important. This study is grounded on the Protection Motivation Theory (PMT), which refers to the cognitive process that people undergo when evaluating their own ability to avoid a certain risk. Results of a survey among 858 flood-prone households in Can Tho city in the Mekong Delta, Vietnam are presented. It is shown that flood-coping appraisal is an important variable in terms of precautionary behaviour. Thus, risk communication should focus more on the potential of precautionary measures to effectively reduce flood damage, as well as on information about how to implement such measures in practice.

  16. Flood Prediction for the Tam Nong District in Mekong Delta Using Hydrological Modelling and Hydrologic Remote Sensing Technique

    Science.gov (United States)

    Kappas, Martin; Nguyen Hong, Quang; Thanh, Nga Pham Thi; Thu, Hang Le Thi; Nguyen Vu, Giang; Degener, Jan; Rafiei Emam, Ammar

    2017-04-01

    There has been an increasing attention to the large trans-boundary Mekong river basin due to various problems related to water management and flood control, for instance. Vietnam Mekong delta is located at the downstream of the river basin where is affected most by this human-induced reduction in flows from the upstream. On the other hand, the flood plain of nine anastomosing channels is increasingly effected by the seawater intrusion due to sea level rising of climate change. This results in negative impacts of salinization, drought, and floods, while formerly flooding had frequently brought positive natural gain of irrigation water and alluvial aggradation. In this research, our aim is to predict flooding for the better water management adaptation and control. We applied the model HEC-SSP 2.1 to analyze flood flow frequency, two-dimensional unsteady flow calculations in HEC-RAS 5.0 for simulating a floodplain inundation. Remote sensing-based water level (Jason-2) and inundation map were used for validation and comparison with the model simulations. The results revealed a reduction of water level at all the monitoring stations, particularly in the last decade. In addition, a trend of the inundation extension gradually declined, but in some periods it remained severe due to water release from upstream reservoirs during the rainy season (October-November). We found an acceptable agreement between the HEC-RAS and remote sensing flooding maps (around 70%). Based on the flood routine analysis, we could conclude that the water level will continue lower and lead to a trend of drought and salinization harsher in the near future. Keywords: Mekong delta, flood control, inundation, water management, hydrological modelling, remote sensing

  17. Extreme anthropogenic erosion: Topsoil Selling in the Mekong Delta and consequences for soil quality

    Science.gov (United States)

    Weigand, Susanne; Sebesvari, Zita; Vien, Duong Minh; Kruse, Jens; Guong, Vo Thi; Amelung, Wulf

    2017-04-01

    Increasing urbanization and industrialization leads to increasing demands for construction material, especially in low income countries. For this purpose topsoil is sometimes removed and used as construction material. Topsoil Selling is practiced around the world from America, Europe and Africa to Asia. In the Mekong Delta, Vietnam farmers physically remove the upper 10-40 cm of their paddy fields and sell it to contractors (= Topsoil Selling, TSS). The excavated material is used for road construction or brick production and therefore the most fertile part of the paddy soil is irrecoverably lost. The temporal effects of topsoil removal on soil quality are not yet fully understood. We hypothesized that after soil removal, soil quality and yield potential are significantly lower compared to the original topsoil. To test this hypothesis, we sampled two chronosequences in two different provinces of the Mekong Delta. The provinces are Sóc Trăng (Control, 1, 2, 3, 8 years after TSS) and Trà Vinh (Control, 3, 5, 8 years after TSS). The sampling areas differ in texture and cultivation practice: clayey-loamy vs. sandy-loamy and double vs. triple rice cropping. For each year of the chronosequence, 4 field sites were investigated. We sampled the Ap, Bg1, and Bg2 horizon up to 40 cm depth as composite samples from 6 to 8 cores per field. Soil organic carbon (Corg) stocks at TSS sites were up to 20 t/ha lower than at Control sites (Control: 50 t/ha) in Sóc Trăng and up to 15 t/ha lower in Tra Vinh (Control: 30 t/ha). Especially the Bg horizons revealed a continuous decline in Corg with time after soil removal. Analysis of available nutrients (Na, K, Ca, Mg, S, Fe, Al, Mn, Zn, Cu) determined by the Mehlich3-Method are still ongoing. Preliminary results, however, suggest that there is not sustainable loss of these elements after selling, but that initial risk of losses are reverted under prolonged management. Phosphorus fractionation according to the Hedley method indicate

  18. Losing ground - scenarios of land loss as consequence of shifting sediment budgets in the Mekong Delta

    Science.gov (United States)

    Schmitt, R. J. P.; Rubin, Z.; Kondolf, G. M.

    2017-10-01

    With changing climate and rising seas, proliferation of hydroelectric dams, instream sand mining, dyking of floodplains, accelerated subsidence from groundwater pumping, accelerated sea-level rise, and other anthropic impacts, it is certain that the Mekong Delta will undergo large changes in the coming decades. These changes will threaten the very existence of the landform itself. The multiplicity of compounding drivers and lack of reliable data lead to large uncertainties in forecasting changes in the sediment budget of the Mekong Delta, its morphology, and the ecosystems and human livelihoods it supports. We compile information on key drivers affecting the sediment budget of the Mekong Delta and compare them to quantify the magnitude of effects from different drivers. We develop a set of likely scenarios for the future development of these drivers and quantify implications for the future of the Mekong Delta using a simplified model of the delta's geometry. If sediment supply to the delta is nearly completely cut off, as would be the case with full buildout of planned dams and current rates of sediment mining, and with continued groundwater pumping at current rates, our model forecasts that the delta will almost completely disappear by the end of this century due to increased rates of delta subsidence and rising sea levels. While local management cannot prevent global sea level rise, model results suggest that there are important management steps that could prolong the persistence of the delta ecosystem and the livelihoods it supports, including a reduction in ground water pumping and maintaining sediment connectivity between the basin and the delta.

  19. Two-year intervention trial to control of fish-borne zoonotic trematodes in giant gourami (Osphronemus goramy) and striped catfish (Pangasianodon hypophthalmus) in nursery ponds in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Madsen, Henry; Thien, P. C.; Nga, H. T. N.

    2015-01-01

    Fish-borne zoonotic trematode parasites (FZT) pose a food safety and public health problem in Vietnam. The transmission cycle is complex as domestic animals, especially dogs, cats, fish-eating birds and pigs together with humans serve as reservoir hosts and contribute to FZT egg contamination of ...

  20. The relation between land use and subsidence in the Vietnamese Mekong delta

    Science.gov (United States)

    The Vietnamese Mekong delta is subsiding due to a combination of natural and human-induced causes. Over the past several decades, large-scale anthropogenic land-use changes have taken place as a result of increased agricultural production, population growth and urbanization in th...

  1. Typology of shrimp farming in Bac Lieu Province, Mekong Delta, using multivariate statistics

    NARCIS (Netherlands)

    Joffre, O.M.; Bosma, R.H.

    2009-01-01

    This study aims to update the typology of shrimp farms in a province of the Mekong Delta's coastal area. We analyzed technical and economic characteristics of 170 farms using factor and cluster analysis on the different variables collected during the survey. This allowed us to characterize four

  2. Science implementation of Forecast Mekong for food and environmental security

    Science.gov (United States)

    Turnipseed, D. Phil

    2012-01-01

    Forecast Mekong is a significant international thrust under the Delta Research and Global Observation Network (DRAGON) of the U.S. Geological Survey (USGS) and was launched in 2009 by the U.S. Department of State and the Foreign Ministers of Cambodia, Laos, Thailand, and Vietnam under U.S. Department of State Secretary Hillary R. Clinton's Lower Mekong Initiative to enhance U.S. engagement with countries of the Lower Mekong River Basin in the areas of environment, health, education, and infrastructure. Since 2009, the USGS has worked closely with the U.S. Department of State; personnel from Cambodia, Laos, Thailand, and Vietnam; nongovernmental organizations; and academia to collect and use research and data from the Lower Mekong River Basin to provide hands-on results that will help decisionmakers in future planning and design for restoration, conservation, and management efforts in the Lower Mekong River Basin. In 2012 Forecast Mekong is highlighting the increasing cooperation between the United States and Lower Mekong River Basin countries in the areas of food and environmental security. Under the DRAGON, Forecast Mekong continues work in interactive data integration, modeling, and visualization system by initiating three-dimensional bathymetry and river flow data along with a pilot study of fish distribution, population, and migratory patterns in the Lower Mekong River Basin. When fully developed by the USGS, in partnership with local governments and universities throughout the Mekong River region, Forecast Mekong will provide valuable planning tools to visualize the consequences of climate change and river management.

  3. Hydro- and sediment dynamics in the estuary zone of the Mekong Delta: case study Dinh An estuary.

    Science.gov (United States)

    Tran, Anh Tuan; Thoss, Heiko; Gratiot, Nicolas; Dussouillez, Philippe; Brunier, Guillaume; Apel, Heiko

    2017-04-01

    The Mekong River is the tenth largest river in the world, covers an area of 795,000 km2, 4400km in length, the main river flows over the six countries including: China, Myanmar, Thailand, Laos, Cambodia and Vietnam. Its water discharge is 470 km3year-1 and the sediment discharge is estimated about 160 million ton year-1. The sediment transported by the Mekong River is the key factor in the formation and development of the delta. It is a vital factor for the stability of the coastline and river banks. Furthermore it compensates land subsidence by floodplain deposition, and is the major natural nutrient source for agriculture and aquaculture. However, only a few studies were conducted to characterize and quantify sediment properties and process in the Delta. Also the morphodynamic processes were hardly studied systematically. Hence, this study targets to fill some important and open knowledge gaps with extensive field works that provide important information about the sediment properties and hydrodynamic processes in different seasons Firstly three field survey campaigns are carried out along a 30 km section of the Bassac River from the beginning of Cu Lao Dung Island to Dinh An estuary in 2015 and 2016. During the field campaign, the movement of the salt wedge and the turbidity were monitored by vertical profiles along the river, as well as discharge measurements by ADCP were carried out at three cross sections continuously for 72 hours. The extension of the salt wedge in the river was determined, along with mixing processes. The movement and dynamics observed under different flow conditions indicate that sediment was pumped during low flow upwards the river, while during high flow net transport towards the sea dominated. Also a distinct difference in the sediment properties in the different seasons was observed, with a general tendency towards a higher proportion of coarser particles in the high flow season. These quantitative results give insights into the

  4. Decomposition of Organic Substrates and their Effect on Mungbean Growth in Two Soils of the Mekong Delta

    Directory of Open Access Journals (Sweden)

    Mathias Becker

    2008-04-01

    Full Text Available Agricultural land use in the Mekong Delta of Vietnam is dominated by intensive irrigated rice cropping systems on both alluvial and acid sulfate soils. A stagnating and occasionally declining productivity may be linked on the alluvial soils to low N use efficiency and low soil organic matter content while on acid sulfate soils to acidity, Al toxicity and P deficiency. For economic reasons, farmers increasingly diversify their cropping system by replacing the dry season rice by high-value horticultural crops grown under upland conditions. However, upland cropping is likely to further exacerbate the soil-related problems. Organic substrates from decentralized waste and waste water management are widely available and may help to alleviate the reported soil problems. During the dry season of 2003/2004, the effect of the application of various types and rates of locally available waste products on crop performance was evaluated at both an alluvial and an acid sulfate soil site. The C and N mineralization dynamics of nine organic substrates from waste and waste water treatment were determined by anaerobic (N and aerobic (C incubation in the laboratory. The response of 12 week-old mungbean (dry matter accumulation to substrate application (1.5 – 6.0 Mg ha−1 was evaluated on a degraded alluvial and on an acid sulfate soil. In the alluvial soil, largest mineralization rates were observed from anaerobic sludge. Biomass increases in 12 week-old mungbean ranged from 25-98% above the unfertilized control. In the acid sulfate soil, highest net-N release rates were observed from aerobic composts with high P content. Mungbean biomass was related to soil pH and exchangeable Al3+ and was highest with the application of aerobic composts. We conclude that the use of organic substrates in the rice-based systems of the Mekong Delta needs to be soil specific.

  5. Linking rapid erosion of the Mekong River delta to human activities.

    Science.gov (United States)

    Anthony, Edward J; Brunier, Guillaume; Besset, Manon; Goichot, Marc; Dussouillez, Philippe; Nguyen, Van Lap

    2015-10-08

    As international concern for the survival of deltas grows, the Mekong River delta, the world's third largest delta, densely populated, considered as Southeast Asia's most important food basket, and rich in biodiversity at the world scale, is also increasingly affected by human activities and exposed to subsidence and coastal erosion. Several dams have been constructed upstream of the delta and many more are now planned. We quantify from high-resolution SPOT 5 satellite images large-scale shoreline erosion and land loss between 2003 and 2012 that now affect over 50% of the once strongly advancing >600 km-long delta shoreline. Erosion, with no identified change in the river's discharge and in wave and wind conditions over this recent period, is consistent with: (1) a reported significant decrease in coastal surface suspended sediment from the Mekong that may be linked to dam retention of its sediment, (2) large-scale commercial sand mining in the river and delta channels, and (3) subsidence due to groundwater extraction. Shoreline erosion is already responsible for displacement of coastal populations. It is an additional hazard to the integrity of this Asian mega delta now considered particularly vulnerable to accelerated subsidence and sea-level rise, and will be exacerbated by future hydropower dams.

  6. Two-year intervention trial to control of fish-borne zoonotic trematodes in giant gourami (Osphronemus goramy) and striped catfish (Pangasianodon hypophthalmus) in nursery ponds in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Madsen, H; Thien, P C; Nga, H T N; Clausen, J H; Dalsgaard, A; Murrell, K D

    2015-12-01

    Fish-borne zoonotic trematode parasites (FZT) pose a food safety and public health problem in Vietnam. The transmission cycle is complex as domestic animals, especially dogs, cats, fish-eating birds and pigs together with humans serve as reservoir hosts and contribute to FZT egg contamination of aquaculture ponds and the environment. This intervention trial was conducted to determine the effectiveness of various on-farm interventions, including reduction in FZT egg contamination through treatment of infected people and domestic animals, reduction in snail density through mud removal from aquaculture ponds prior to fish stocking, and various other measures in reducing FZT infection in juvenile striped catfish (Pangasianodon hypophthalmus) and giant gourami (Osphronemus goramy). Interventions were implemented on 5 farms for each fish species during production cycles in 2009 and 2010 while 5 similar farms for each species served as control. For both fish species, both prevalence and intensity of infection did not differ significantly between intervention and non-intervention farms prior to the interventions. The interventions significantly reduced both prevalence and intensity of FZT infection in the juvenile fish compared to control ponds. For giant gourami, odds of infection in intervention ponds was 0.13 (95% CL: 0.09-0.20; p<0.001) of that in non-intervention ponds after the 2009 trial and 0.07 (0.03-0.14; p<0.001) after the 2010 trial. For striped catfish, these figures were 0.17 (0.08-0.35; p<0.001) after the 2009 trial while after the 2010 trial all ponds with interventions were free from infection. Metacercariae intensity (no. of metacercariae/fish) in giant gourami from intervention ponds was 0.16 (0.11-0.23; p<0.001) of that in fish from non-intervention ponds after the 2009 trial and 0.07 (0.04-0.15; p<0.001) after the 2010 trial; for striped catfish these figures were 0.18 (0.09-0.36; p<0.001) and 0.00 (confidence limits not estimated), respectively. The

  7. Coastal and Estuarine Mangrove Squeeze in the Mekong and Saigon Delta

    Science.gov (United States)

    Stive, M.

    2016-02-01

    Both in the Mekong and Saigon deltas coastal squeeze is a frequent and pregnant problem, which leads to amazingly alarmous coastal and estuarine erosion rates. From the landside the squeeze is due to encroaching dike relocations and agri- and aquacultures, from the sea side it is due to decreasing sediment sources and relative sea level rise. These multiple pressures at some locations, certainly away from the sediment sources (like Ca Mau) leads to unprecedentent erosion rates. Managed retreat may be a longer term solution, but this will require a new way of thinking. Sandy and silt nourishment strategies may be an innovative alternative, but will require underbuilding scientific and practical research.

  8. Balancing options for shrimp farming : a landscape approach to investigate the future of shrimp farming in the Mekong Delta

    NARCIS (Netherlands)

    Joffre, O.M.

    2015-01-01

    Balancing options for shrimp farming

    A landscape approach to investigate the future of shrimp farming in the Mekong Delta

    Olivier Joffre

    While providing an option for development in coastal areas, shrimp farming is usually associated with high environmental

  9. Virus diseases risk-factors associated with shrimp farming practices in rice-shrimp and intensive culture systems in Mekong Delta Viet Nam

    NARCIS (Netherlands)

    Duc, P.M.; Tuyet Hoa, T.T.; Nguyen Thanh Phuong,; Bosma, R.H.; Huynh V., Hien; Tran N., Tuan

    2015-01-01

    In Mekong Delta, viral infection, including white spot syndrome virus (WSSV), monodon baculovirus (MBV), heptopancreatic parvovirus (HPV), infectious hypodermal and hematopoietic necrosis virus (IHHNV) and gill-associated nidovirus (GAV) frequently infect cultured shrimp starting at the postlarvae

  10. Has dyke development in the Vietnamese Mekong Delta shifted flood hazard downstream?

    Science.gov (United States)

    Van Khanh Triet, Nguyen; Viet Dung, Nguyen; Fujii, Hideto; Kummu, Matti; Merz, Bruno; Apel, Heiko

    2017-08-01

    In the Vietnamese part of the Mekong Delta (VMD) the areas with three rice crops per year have been expanded rapidly during the last 15 years. Paddy-rice cultivation during the flood season has been made possible by implementing high-dyke flood defenses and flood control structures. However, there are widespread claims that the high-dyke system has increased water levels in downstream areas. Our study aims at resolving this issue by attributing observed changes in flood characteristics to high-dyke construction and other possible causes. Maximum water levels and duration above the flood alarm level are analysed for gradual trends and step changes at different discharge gauges. Strong and robust increasing trends of peak water levels and duration downstream of the high-dyke areas are found with a step change in 2000/2001, i.e. immediately after the disastrous flood which initiated the high-dyke development. These changes are in contrast to the negative trends detected at stations upstream of the high-dyke areas. This spatially different behaviour of changes in flood characteristics seems to support the public claims. To separate the impact of the high-dyke development from the impact of the other drivers - i.e. changes in the flood hydrograph entering the Mekong Delta, and changes in the tidal dynamics - hydraulic model simulations of the two recent large flood events in 2000 and 2011 are performed. The hydraulic model is run for a set of scenarios whereas the different drivers are interchanged. The simulations reveal that for the central VMD an increase of 9-13 cm in flood peak and 15 days in duration can be attributed to high-dyke development. However, for this area the tidal dynamics have an even larger effect in the range of 19-32 cm. However, the relative contributions of the three drivers of change vary in space across the delta. In summary, our study confirms the claims that the high-dyke development has raised the flood hazard downstream. However, it is not

  11. Has dyke development in the Vietnamese Mekong Delta shifted flood hazard downstream?

    Directory of Open Access Journals (Sweden)

    N. V. K. Triet

    2017-08-01

    Full Text Available In the Vietnamese part of the Mekong Delta (VMD the areas with three rice crops per year have been expanded rapidly during the last 15 years. Paddy-rice cultivation during the flood season has been made possible by implementing high-dyke flood defenses and flood control structures. However, there are widespread claims that the high-dyke system has increased water levels in downstream areas. Our study aims at resolving this issue by attributing observed changes in flood characteristics to high-dyke construction and other possible causes. Maximum water levels and duration above the flood alarm level are analysed for gradual trends and step changes at different discharge gauges. Strong and robust increasing trends of peak water levels and duration downstream of the high-dyke areas are found with a step change in 2000/2001, i.e. immediately after the disastrous flood which initiated the high-dyke development. These changes are in contrast to the negative trends detected at stations upstream of the high-dyke areas. This spatially different behaviour of changes in flood characteristics seems to support the public claims. To separate the impact of the high-dyke development from the impact of the other drivers – i.e. changes in the flood hydrograph entering the Mekong Delta, and changes in the tidal dynamics – hydraulic model simulations of the two recent large flood events in 2000 and 2011 are performed. The hydraulic model is run for a set of scenarios whereas the different drivers are interchanged. The simulations reveal that for the central VMD an increase of 9–13 cm in flood peak and 15 days in duration can be attributed to high-dyke development. However, for this area the tidal dynamics have an even larger effect in the range of 19–32 cm. However, the relative contributions of the three drivers of change vary in space across the delta. In summary, our study confirms the claims that the high-dyke development has raised the flood

  12. Managing flood risks in the Mekong Delta: How to address emerging challenges under climate change and socioeconomic developments

    OpenAIRE

    Hoang, L.P.; Biesbroek, R.; Tri, V.P.D.; Kummu, M.; van Vliet, M.T.H.; Leemans, R.; Kabat, P.; Ludwig, F.

    2018-01-01

    Climate change and accelerating socioeconomic developments increasingly challenge flood-risk management in the Vietnamese Mekong River Delta—a typical large, economically dynamic and highly vulnerable delta. This study identifies and addresses the emerging challenges for flood-risk management. Furthermore, we identify and analyse response solutions, focusing on meaningful configurations of the individual solutions and how they can be tailored to specific challenges using expert surveys, conte...

  13. The influence of delta formation mechanism on geotechnical property sequence of the late Pleistocene–Holocene sediments in the Mekong River Delta

    Directory of Open Access Journals (Sweden)

    Truong Minh Hoang

    2016-11-01

    Full Text Available The aim of the study was to characterize a variety of microstructure development-levels and geotechnical property sequences of the late Pleistocene–Holocene deposits in the Mekong River delta (MRD, and the paper furthermore discusses the influences of delta formation mechanisms on them. The survey associated the geotechnical engineering and the sedimentary geology of the late Pleistocene–Holocene deposits at five sites and also undifferentiated Pleistocene sediments. A cross-section which was rebuilt in the delta progradation-direction and between the Mekong and Bassac rivers represents the stratigraphy. Each sedimentary unit was formed under a different delta formation mechanism and revealed a typical geotechnical property sequence. The mechanical behaviors of the sediment succession in the tide-dominated delta with significant fluvial-activity and material source tend to be more cohesionless soils and strengths than those in the tide- and wave-dominated delta and even the coast. The particular tendency of the mechanical behavior of the deposit succession can be reasonably estimated from the delta formation mechanism. The characteristics of the clay minerals from the Mekong River produced the argillaceous soil which does not have extremely high plasticity. The microstructure development-levels are low to very high indicating how to choose hydraulic conductivity value, k, for estimating overconsolidation ratio, OCR, by the piezocone penetration tests (CPTU. The OCR of sediments in the delta types strangely change with depth but none less than 1. The post-depositional processes significantly influenced the microstructure development, particularly the dehydrating and oxidizing processes.

  14. Potential collaboration with the private sector for the provision of ambulatory care in the Mekong region, Vietnam

    Science.gov (United States)

    Duc, Ha Anh; Sabin, Lora L.; Cuong, Le Quang; Thien, Duong Duc; Feeley, Rich

    2012-01-01

    Background Over the past two decades, health insurance in Vietnam has expanded nationwide. Concurrently, Vietnam's private health sector has developed rapidly and become an increasingly integral part of the health system. To date, however, little is understood regarding the potential for expanding public-private partnerships to improve health care access and outcomes in Vietnam. Objective To explore possibilities for public-private collaboration in the provision of ambulatory care at the primary level in the Mekong region, Vietnam. Design We employed a mixed methods research approach. Qualitative methods included focus group discussions with health officials and in-depth interviews with managers of private health facilities. Quantitative methods encompassed facility assessments, and exit surveys of clients at the same private facilities. Results Discussions with health officials indicated generally favorable attitudes towards partnerships with private providers. Concerns were also voiced, regarding the over- and irrational use of antibiotics, and in terms of limited capacity for regulation, monitoring, and quality assurance. Private facility managers expressed a willingness to collaborate in the provision of ambulatory care, and private providers facilites were relatively well staffed and equipped. The client surveys indicated that 80% of clients first sought treatment at a private facility, even though most lived closer to a public provider. This choice was motivated mainly by perceptions of quality of care. Clients who reported seeking care at both a public and private facility were more satisfied with the latter. Conclusions Public-private collaboration in the provision of ambulatory care at the primary level in Vietnam has substantial potential for improving access to quality services. We recommend that such collaboration be explored by Vietnamese policy-makers. If implemented, we strongly urge attention to effectively managing such partnerships, establishing a

  15. Iron isotope constraints on arsenic release from Mekong Delta sediments, Cambodia

    Science.gov (United States)

    Matsumoto, T.; Yamaguchi, K. E.; Hirata, T.; Yamagata, Y.; Yamaguchi, A.; Abe, G.

    2017-12-01

    Arsenic-contaminated groundwater is a world-wide environmental problem and threatens more than 100 million people living in delta areas of South, SE and East Asia. It is typically associated with reducing aquifers with organic-rich alluvial sediments, little thermal gradients, low sulfate concentrations, and slow flushing rates. Such conditions are typical for low-lying countries in Asian deltas; however, compared to Bangladesh, Cambodia has received far less attention. Upon reductive dissolution of Fe-(oxyhydr)oxides that adsorbed As, Fe and As are released into solution as dissolved Fe2+ and arsenate, respectively. Following the oxidation of dissolved Fe2+, newly-formed Fe-(oxyhydr)oxides adsorb As again. Thus, in anoxic waters, concentrations of As correlate with those of dissolved Fe2+. Fluctuating redox conditions in the aquifer are control As release, although inhibition of adsorption of arsenate and arsenite onto the Fe-(oxyhydr)oxides occurs when the concentrations of phosphate, bicarbonate, silicate, and/or organic matter become sufficiently high. Biogeochemical redox reactions of Fe result in significant isotope fractionation (e.g., Johnson et al., 2008). We hypothesized that magnitude of isotope fractionation of Fe in the aquifer sediments, reflecting repeated (incomplete) redox reactions of Fe, may be proportional to the amount of total As release. We aim to calibrate the As release from aquifer sediment by Fe isotope analysis. As a preliminary study, series of sediment samples were collected from the Mekong Delta, Cambodia, in September 2016. Based on measurements by XRF, ICP-AES and ICP-MS, concentrations of As varied significantly covering the range from 4.5 to 15.5 µg/g with a median value of 11 µg/g (higher than the average crustal value of 5 µg/g), and those of Fe is from 2.6 to 9.7 wt.% with a median value of 7.1 wt.%. Concentrations of As and Fe show positive correlation (R2 = 0.72), indicating an effective redox cycling of Fe and As as

  16. Climate proofing aquaculture: a case study on pangasius farming in the Mekong

    NARCIS (Netherlands)

    Anh, L.N.

    2014-01-01

    Abstract

    Vietnam is among the top five countries that will be most affected by sea level rise. This study aimed to assess the subsequent impacts of flooding and salinity intrusion on, and to evaluate suitable adaptation strategies for the Mekong Delta's pangasius farming

  17. Vulnerability and Risk of Agro-ecosystems Facing Increased Salinity Intrusion in the Mekong Delta, Viet Nam

    Science.gov (United States)

    Renaud, F.; Sebesvari, Z.; Nguyen, M. T.; Hagenlocher, M.

    2016-12-01

    The Vietnamese portion of the Mekong Delta increasingly suffers from salinity intrusion in its freshwater system, as exemplified by the historically high salinity levels recorded during the 2016 dry season. Although this exceptional situation was linked to the El Niño phenomena, many factors contribute to an increasing salinization of coastal areas. Salinity intrusion is a natural process in this tidal area but its extent is increasing and projected to worsen due to increased demand for water, diversion/storage of water flows in the Mekong river and its tributaries, land subsidence linked to groundwater over-abstraction, changes in land use and water management in coastal areas, and sea level rise. The Mekong Delta remains predominantly an agricultural landscape which contributes the majority of the rice, aquaculture, and fruit production of the country. These systems will need to be adapted to increased salinity levels. We will present results from two research projects, DeltAdapt and DELTAS, which were designed to allow understanding of, respectively (1) the main drivers of change of agro-ecosystems in coastal areas of the delta and (2) the relative vulnerabilities and risks deltaic social-ecological systems face with respect to various environmental hazards. We used the Global Delta Vulnerability Index developed within the DELTAS project to characterize the vulnerabilities and risks faced by coastal provinces of the delta with respect to salinity intrusion. The analysis allows us to understand which social, economic, and ecological variables index explain the relative vulnerability of the provinces. In addition, drivers of change (e.g. policy, economic, social, environmental) of coastal agro-ecosystems were systematically analyzed through 80 interviews and 7 focus group discussions in the provinces of Kien Giang and Soc Trang within the DeltAdapt project. This was combined with the analysis of Vietnamese policies to determine which are the important drivers of

  18. Challenges and Approaches in River Delta Planning - report on training workshop

    NARCIS (Netherlands)

    Wosten, J.H.M.; Douven, W.; Long Phi, H.; Fida Abdullah Khan, M.

    2012-01-01

    River delta’s, like the Mekong Delta (Vietnam), Ganges-Brahmaputra Delta (Bangladesh), Irrawady (Myanmar) and Ciliwung Delta (Indonesia) are developing rapidly and characterized by large-scale urbanization and industrialization processes. They are facing serious planning challenges related to issues

  19. Applications of multispectral imagery to water resources development planning in the lower Mekong Basin (Khmer Republic, Laos, Thailand and Viet-Nam)

    Science.gov (United States)

    Vankiere, W. J.

    1973-01-01

    The use of ERTS imagery for water resources planning in the lower Mekong Basin relates to three major issues: (1) it complements data from areas, which have been inaccessible in the past because of security; this concerns mainly forest cover of the watersheds, and geological features, (2) it refines ground surveys; this concerns mainly land forms, and soils of existing and planned irrigation perimeters, and (3) it provides new information, which would be almost or entirely impossible to detect with ground surveys or conventional photography; this concerns the mechanism of flooding and drainage of the delta; siltation of the Great Lake and mapping of acidity, possibly also of salinity, in the lower delta; sedimentation and fisheries in the Mekong Delta estuarine areas.

  20. Taxonomic Notes on the Genus Delta de Saussure (Hymenoptera: Vespidae: Eumeninae from Vietnam

    Directory of Open Access Journals (Sweden)

    Nguyen, Lien Thi Phuong

    2015-02-01

    Full Text Available A taxonomic study of the genus Delta de Saussure, 1855 from Vietnam is presented. A total of four species are recorded: D. campaniforme campaniforme (Fabricius, 1775, D. conoideum (Gmelin, 1790, D. esuriens esuriens (Fabricius, 1787, and D. pyriforme pyriforme (Fabricius, 1775. Of these, D. campaniforme campaniforme was first recorded from Vietnam by de Saussure et al., 1904, under the name Eumenes esuriens and is now reconfirmed to occur in Vietnam after more than 100 years, and D. conoideum is newly recorded from Vietnam. A key to species based on morphological characters is given with illustrations, and distributional records in Vietnam are also provided.

  1. Life cycle assessment of intensive striped catfish farming in the Mekong Delta for screening hotspots as input to environmental policy and research agenda

    NARCIS (Netherlands)

    Bosma, R.H.; Pham Thi Ahn,; Potting, J.

    2011-01-01

    Purpose Intensive striped catfish production in the Mekong Delta has, in recent years, raised environmental concerns. We conducted a stakeholder-based screening life cycle assessment (LCA) of the intensive farming system to determine the critical environmental impact and their causative processes in

  2. Influence of salinity intrusion on the speciation and partitioning of mercury in the Mekong River Delta

    Science.gov (United States)

    Noh, Seam; Choi, Mijin; Kim, Eunhee; Dan, Nguyen Phuoc; Thanh, Bui Xuan; Ha, Nguyen Thi Van; Sthiannopkao, Suthipong; Han, Seunghee

    2013-04-01

    The lower Mekong and Saigon River Basins are dominated by distinctive monsoon seasons, dry and rainy seasons. Most of the Mekong River is a freshwater region during the rainy season, whereas during the dry season, salt water intrudes approximately 70 km inland. To understand the role of salinity intrusion controlling Hg behavior in the Mekong and Saigon River Basins, Hg and monomethylmercury (MMHg) in surface water and sediment of the Mekong River and in sediment of the Saigon River were investigated in the dry season. Sediment Hg distribution, ranging from 0.12 to 0.76 nmol g-1, was mainly controlled by organic carbon distribution in the Mekong River; however, the location of point sources was more important in the Saigon River (0.21-0.65 nmol g-1). The MMHg concentrations in Mekong (0.16-6.1 pmol g-1) and Saigon (0.70-8.7 pmol g-1) sediment typically showed significant increases in the estuarine head, with sharp increases of acid volatile sulfide. Unfiltered Hg (4.6-222 pM) and filtered Hg (1.2-14 pM) in the Mekong River increased in the estuarine zone due to enhanced particle loads. Conversely, unfiltered MMHg (0.056-0.39 pM) and filtered MMHg (0.020-0.17 pM) was similar between freshwater and estuarine zones, which was associated with mixing dilution of particulate MMHg by organic- and MMHg-depleted resuspended sediment. Partitioning of Hg between water and suspended particle showed tight correlation with the partitioning of organic carbon across study sites, while that of MMHg implied influences of chloride: enhanced chloride in addition to organic matter depletion decreased particulate MMHg in the estuarine zone. Primary production was an important determinant of inter-annual variation of particulate Hg and sediment MMHg. The bloom year showed relatively low particulate Hg with low C/N ratio, indicating biodilution of Hg. In contrast, the percentage of MMHg in sediment increased significantly in the bloom year, likely due to greater availability of

  3. Web-Based Water Accounting Scenario Platform to Address Uncertainties in Water Resources Management in the Mekong : A Case Study in Ca River Basin, Vietnam

    Science.gov (United States)

    Apirumanekul, C.; Purkey, D. R.; Pudashine, J.; Seifollahi-Aghmiuni, S.; Wang, D.; Ate, P.; Meechaiya, C.

    2017-12-01

    Rapid economic development in the Mekong Region is placing pressure on environmental resources. Uncertain changes in land-use, increasing urbanization, infrastructure development, migration patterns and climate risks s combined with scarce water resources are increasing water demand in various sectors. More appropriate policies, strategies and planning for sustainable water resource management are urgently needed. Over the last five years, Vietnam has experienced more frequent and intense droughts affecting agricultural and domestic water use during the dry season. The Ca River Basin is the third largest river basin in Vietnam with 35% of its area located in Lao PDR. The delta landscape comprises natural vegetation, forest, paddy fields, farming and urban areas. The Ca River Basin is experiencing ongoing water scarcity that impacts on crop production, farming livelihoods and household water consumption. Water scarcity is exacerbated by uncertainties in policy changes (e.g. changes in land-use, crop types), basin development (e.g. reservoir construction, urban expansion), and climate change (e.g. changes in rainfall patterns and onset of monsoon). The Water Evaluation And Planning (WEAP) model, with inputs from satellite-based information and institutional data, is used to estimate water supply, water use and water allocation in various sectors (e.g. household, crops, irrigation and flood control) under a wide range of plausible future scenarios in the Ca River Basin. Web-Based Water Allocation Scenario Platform is an online implementation of WEAP model structured in terms of a gaming experience. The online game, as an educational tool, helps key agencies relevant to water resources management understand and explore the complexity of integrated system of river basin under a wide range of scenarios. Performance of the different water resources strategies in Ca River Basin (e.g. change of dam operation to address needs in various sectors, construction of dams, changes

  4. Mangrove restoration in Vietnam : Key considerations and a practical guide

    NARCIS (Netherlands)

    Marchand, M.

    2008-01-01

    In Vietnam mangrove rehabilitation has a long history and gained momentum after the war that destroyed huge forested areas, especially in the Mekong Delta. In addition, in various places mangrove have been and still are being planted specifically as a way to protect shorelines and sea-dykes from

  5. The Brown Water Navy in the Mekong Delta: COIN in the Littorals and Inland Waters

    Science.gov (United States)

    2008-01-01

    frrmly under the control of the communist insurgency known as the Viet Cong (VC). The absence of major cities and physical infrastructure south of...control the physical environment, win popular support, ~\\l) address needs of the people, and legitimacy of the local government.3 In South Vietnam...the region. The Genesis of the Viet COllg Subsequent to the French defeat at Dien Bien Phu, the Geneva Accords divided Vietnam into the Democratic

  6. Channel Bottom Morphology in the Deltaic Reach of the Song Hau (mekong) River Channel in Vietnam

    Science.gov (United States)

    Allison, M. A.; Weathers, H. D., III; Meselhe, E. A.

    2016-02-01

    Boat-based, channel bathymetry and bankline elevation studies were conducted in the tidal and estuarine Mekong River channel using multibeam bathymetry and LIDAR corrected for elevation by RTK satellite positioning. Two mapping campaigns, one at high discharge in October 2014 and one at low discharge in March 2015, were conducted in the lower 100 km reach of the Song Hau distributary channel to (1) examine bottom morphology and its relationship to sediment transport, and (2) to provide information to setup the grid for a multi-dimensional and reduced complexity models of channel hydrodynamics and sediment dynamics. Sand fields were identified in multibeam data by the presence of dunes that were as large as 2-4 m high and 40-80 m wavelength and by clean sands in bottom grabs. Extensive areas of sand at the head and toe of mid-channel islands displayed 10-25 m diameter circular pits that could be correlated with bucket dredge, sand mining activities observed at some of the sites. Large areas of the channel floor were relict (containing little or no modern sediment) in the high discharge campaign, identifiable by the presence of along channel erosional furrows and terraced outcrops along the channel floor and margins. Laterally extensive flat areas were also observed in the channel thalweg. Both these and the relict areas were sampled by bottom grab as stiff silty clays. Complex cross-channel combinations of these morphologies were observed in some transects, suggesting strong bottom steering of tidal and riverine currents. Relative to high discharge, transects above and below the salt penetration limit showed evidence of shallowing in the thalweg and adjacent sloping areas at low discharge in March 2015. This shallowing, combined with the reduced extent of sand fields and furrowed areas, and soft muds in grabs, suggests seasonal trapping of fine grained sediment is occurring by estuarine and tidal circulation.

  7. Developing management packages for acid sulphate soils based on farmer and expert knowledge : field study in the Mekong Delta, Viet Nam

    OpenAIRE

    Quang Tri, Le

    1996-01-01


    Effective interaction of farmers' expertise and expert knowledge has been a special point of attention for this study. The objectives of the study were to describe the process of interaction between farmers and experts in improving the use of acid sulphate soils and to point out difficulties encountered. Actual conditions for four major areas were described including variabilities. Four representative areas: Tan Thanh, Tri Ton, Phung Hiep, and Hong Dan in the Mekong Delta, Viet Nam...

  8. Impacts of dyke development in flood prone areas in the Vietnamese Mekong Delta to downstream flood hazard

    Science.gov (United States)

    Khanh Triet Nguyen, Van; Dung Nguyen, Viet; Fujii, Hideto; Kummu, Matti; Merz, Bruno; Apel, Heiko

    2016-04-01

    The Vietnamese Mekong Delta (VMD) plays an important role in food security and socio-economic development of the country. Being a low-lying coastal region, the VMD is particularly susceptible to both riverine and tidal floods, which provide, on (the) one hand, the basis for the rich agricultural production and the livelihood of the people, but on the other hand pose a considerable hazard depending on the severity of the floods. But despite of potentially hazardous flood, the area remain active as a rice granary due to its nutrient-rich soils and sediment input, and dense waterways, canals and the long standing experience of the population living with floods. In response to both farmers' requests and governmental plans, the construction of flood protection infrastructure in the delta progressed rapidly in the last twenty years, notably at areas prone to deep flooding, i.e. the Plain of Reeds (PoR) and Long Xuyen Quadrangle (LXQ). Triple rice cropping becomes possible in farmlands enclosed by "full-dykes", i.e. dykes strong and high enough to prevent flooding of the flood plains for most of the floods. In these protected flood plains rice can be grown even during the peak flood period (September to November). However, little is known about the possibly (and already alleged) negative impacts of this fully flood protection measure to downstream areas. This study aims at quantifying how the flood regime in the lower part of the VMD (e.g. Can Tho, My Thuan, …) has been changed in the last 2 recent "big flood" events of 2000 and 2011 due to the construction of the full-dyke system in the upper part. First, an evaluation of 35 years of daily water level data was performed in order to detect trends at key gauging stations: Kratie: upper boundary of the Delta, Tan Chau and Chau Doc: areas with full-dyke construction, Can Tho and My Thuan: downstream. Results from the Mann-Kendall (MK) test show a decreasing trend of the annual maximum water level at 3 stations Kratie, Tan

  9. Nitrogen Leaching in Intensive Cropping Systems in Tam Duong District, Red River Delta of Vietnam

    OpenAIRE

    Trinh, M.V.; Keulen, van, H.; Roetter, R.P.

    2010-01-01

    The environmental and economic consequences of nitrogen (N) lost in rice-based systems in Vietnam is important but has not been extensively studied. The objective of this study was to quantify the amount of N lost in major cropping systems in the Red River Delta. An experiment was conducted in the Red River Delta of Vietnam, on five different crops including rose, daisy, cabbage, chili, and a rice–rice–maize rotation during 2004 and 2005. Core soil samples were taken periodically in 20-cm inc...

  10. Population dynamics, delta vulnerability and environmental change: comparison of the Mekong, Ganges–Brahmaputra and Amazon delta regions

    OpenAIRE

    Szabo, S.; Brondizio, E.; Renaud, F.G.; Hetrick, S.; Nicholls, R.; Matthews, Z.; Tessler, Z; Tejedor, A; Sebesvari, Z; Foufoula-Georgiou, E; da Costa, S; Dearing, J.A.

    2016-01-01

    Tropical delta regions are at risk of multiple threats including relative sea level rise and human alterations, making them more and more vulnerable to extreme floods, storms, surges, salinity intrusion, and other hazards which could also increase in magnitude and frequency with a changing climate. Given the environmental vulnerability of tropical deltas, understanding the interlinkages between population dynamics and environmental change in these regions is crucial for ensuring efficient pol...

  11. Persistent organic pollutants in wetlands of the Mekong Basin

    Science.gov (United States)

    Triet, Tran; Barzen, Jeb Anthony; Choowaew, Sansanee; Engels, Jon Michael; Ni, Duong Van; Mai, Nguyen Anh; Inkhavilay, Khamla; Soben, Kim; Sethik, Rath; Gomotean, Bhuvadol; Thuyen, Le Xuan; Kyi, Aung; Du, Nguyen Huy; Nordheim, Richard; Lam, Ho Si Tung; Moore, Dorn M.; Wilson, Scott

    2013-01-01

    In this study, the presence and concentration of persistent organic pollutants (POP) were assessed in surface sediments collected from a wide variety of wetlands located throughout the Mekong Basin in Myanmar, Lao People’s Democratic Republic (PDR), Thailand, Cambodia, and Vietnam. Of the 39 POPs tested in 531 sediment samples, dichlorodiphenyltrichloroethane (DDT) and its metabolites endosulfan, hexachlorobenzene (HCB), and endrin were most commonly detected. Even though DDT was banned in the 1990s, some use of DDT may still be occurring in the Mekong Basin. The amount of metabolites for DDT—dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD)—found, however, suggests that use of DDT is on the decline throughout the region. HCB and endrin were found distributed broadly throughout the Mekong Basin but not in high amounts. The concentration and distribution of endosulfan and its metabolites represent a serious problem requiring further study and management action. While the total loading of POPs in wetland sediments of the Mekong Basin was generally low, hotspot sites occurred where concentrations exceeded established ecological risk thresholds. For example, wetlands of the open, dry dipterocarp forest of northern Cambodia and Vietnam as well as wetlands in the Mekong Delta of Vietnam contained high concentrations of some POPs. High concentrations of POPs were detected in some wetlands important for biodiversity conservation. Hotspots identified in wetlands such as the Tonle Sap not only had concentrations of DDT and DDE that exceeded Canadian and U.S. benchmarks, but fauna sampled in the area also showed high degrees of bioaccumulation of the same substances. Further and more extensive attention to monitoring POP presence in water birds, fish, and other aquatic organisms is warranted because of the bioaccumulation of these chemicals at higher levels in the food chain. This study represents a collaboration of eight universities from

  12. Morphodynamics of a cyclic prograding delta: the Red River, Vietnam

    NARCIS (Netherlands)

    Maren, D.S. van

    2004-01-01

    River deltas are inhabited by over 60% of the world population, and are, consequently, of paramount agricultural and economical importance. They constitute unique wetland envi ronments which gives river deltas ecological importance as well. Additionally, many deltas contain large accumulations of

  13. Tillage and water management for riceland productivity in acid sulfate soils of the Mekong delta, Vietnam.

    NARCIS (Netherlands)

    Minh, L.Q.; Tuong, T.P.; Mensvoort, van M.E.F.; Bouma, J.

    1997-01-01

    Acid sulfate soils are characterized by low pH and high concentrations of aluminum, sulfate, iron and hydrogen sulfide. Removal of at least part of these substances is a prerequisite for land use, at least in severely acid soils. In this study, the effectiveness of harrowing and flushing with

  14. Soil potassium dynamics under intensive rice cropping. A case study in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Nguyen, M.H.

    2003-01-01

    Keywords:potassium, nutrient budgets, nutrient depletion, fertilizer, kinetics, adsorption,desorption, fixation, release, modeling, rice cropping system,

  15. Sustainable Development of Integrated Rice-fish Polyculture Systems in the Mekong Delta of Vietnam

    Directory of Open Access Journals (Sweden)

    Duong Nhut Long

    2003-01-01

    Full Text Available Huit variétés de niébé améliorées et une locale (témoin ont été testées en champ pendant trois ans en vue d'évaluer leur performance à produire à la fois des graines et du fourrage. Les résultats obtenus montrent que les taux de germination et de croissance étaient élevés (80% pour toutes les variétés étudiées. Les moyennes de rendement étaient respectivement de 1262 à 3598 kg/ha pour la production de fourrage sec et de 528 à 1149 kg/ha pour la production de graines. Les variétés IAR 4/48/15-1, IAR 72 et TVU 12349 ont produit la plus grande quantité de feuilles vertes (&amp;amp;amp;amp;gt; 50% au stade de la récolte de graines durant la saison sèche tandis que les variétés IAR 4/48/15-1, IAR 7/180-4-5 et TVU 12349 ont produit le plus grand nombre de gousses par plant. Le poids de 100 graines le plus élevé a été produit par la variété IT89KD-288 et la variété témoin (Kananado. Le pourcentage moyen de la matière protéique variait de 15,2 à 21,6%.Une faible corrélation a été observée entre les rendements en graines, les rendements en fourrage et le rapport gousses/plant. Pour l'augmentation du revenu des fermiers, les variétés TVU 12349, IT89KD-288, IAR 7/180-4-12 et IAR 4/48/15-1 s'avèrent les plus performantes pour ces paramètres étudiés et sont à recommander dans un système de production intégré.

  16. Clonal occurrence of Salmonella Weltevreden in cultured shrimp in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Uddin, Gazi Md Noor; Larsen, Marianne Halberg; Barco, Lisa

    2015-01-01

    . Weltevreden was susceptible to most antimicrobials tested, with a few strains being resistant to florfenicol, chloramphenicol, sulfamethoxazole or trimethoprim. Future studies of the ecology of S. Weltevreden should establish if this serovar may survive better and even multiply in warm-water shrimp farm...

  17. Comparing the costs and benefits of floating rice-based and intensive rice-based farming systems in the Mekong delta

    OpenAIRE

    Van Kien Nguyen; Oc Van Vo; Duc Ngoc Huynh

    2015-01-01

    This paper compares financial costs and benefits of floating rice-based and intensive rice farming systems using data from focus group discussions and household survey in four locations in the Mekong Delta. We argue that the net financial benefit per 1000m2 of integrated floating rice-based farming systems is greater than the net financial benefit of intensive rice farming system. The total net benefit of floating rice-leeks shows the highest net benefit (VND 24.8 mil./1000 m2), followed by f...

  18. Coupling environmental, social and economic models to understand land-use change dynamics in the Mekong Delta

    Directory of Open Access Journals (Sweden)

    Alexis eDrogoul

    2016-03-01

    Full Text Available The Vietnamese Mekong Delta has undergone in recent years a considerable transformation in agricultural land-use, fueled by a boom of the exportation, an increase of population, a focus on intensive crops, but also environmental factors like sea level rise or the progression of soil salinity. These transformations have been, however, largely misestimated by the ten-year agricultural plans designed at the provincial levels, on the predictions of which, though, most of the large-scale investments (irrigation infrastructures, protection against flooding or salinity intrusion, and so on are normally planned. This situation raises the question of how to explain the divergence between the predictions used as a basis for these plans and the actual situation. Answering it could, as a matter of fact, offer some insights on the dynamics at play and hopefully allow designing them more accurately.The dynamics of land-use change at a scale of a region results from the interactions between heterogeneous actors and factors at different scales, among them institutional policies, individual farming choices, land-cover and environmental changes, economic conditions, social dynamics, just to name a few. Understanding its evolution, for example, in this case, to better support agricultural planning, therefore requires the use of models that can represent the individual contributions of each actor or factor, and of course their interactions.We address this question through the design of an integrated hybrid model of land-use change in a specific and carefully chosen case study, which relies on the central hypothesis that the main force driving land-use change is actually the individual choices made by farmers at their local level. Farmers are the actors who decide (or not to switch from one culture to another and the shifts observed at more global levels (village, district, province, region are considered, in this model, as a consequence of the aggregation of these

  19. Impact of value chain governance on the development of small scale shrimp farmers in Vietnam

    OpenAIRE

    T. M. H. Ho; P. Burny

    2016-01-01

    Purpose of this paper is to identify the tendency of shrimp value chain development and impact of its governance on the small scale shrimp farmers in Vietnam. Design/methodology/approach - Data from the shrimp farmers surveys in Mekong delta, Vietnam from 2008-2010 with the update information in 2014 were taken to analyse by the value chain analysis method. Findings – Traditional governance type of the shrimp value chain in the early state (before 2004) showed the different levels of coordina...

  20. Impact of value chain governance on the development of small scale shrimp farmers in Vietnam

    OpenAIRE

    Ho Thi Minh, Hop; Burny, Philippe

    2016-01-01

    Purpose of this paper is to identify the tendency of shrimp value chain development and impact of its governance on the small scale shrimp farmers in Vietnam. Design/methodology/approach - Data from the shrimp farmers surveys in Mekong delta, Vietnam from 2008-2010 with the update information in 2014 were taken to analyse by the value chain analysis method. Findings – Traditional governance type of the shrimp value chain in the early state (before 2004) showed the different levels of co...

  1. Closing the irrigation deficit in Cambodia: Implications for transboundary impacts on groundwater and Mekong River flow

    Science.gov (United States)

    Erban, Laura E.; Gorelick, Steven M.

    2016-04-01

    Rice production in Cambodia, essential to food security and exports, is largely limited to the wet season. The vast majority (96%) of land planted with rice during the wet season remains fallow during the dry season. This is in large part due to lack of irrigation capacity, increases in which would entail significant consequences for Cambodia and Vietnam, located downstream on the Mekong River. Here we quantify the extent of the dry season ;deficit; area in the Cambodian Mekong River catchment, using a recent agricultural survey and our analysis of MODIS satellite data. Irrigation of this land for rice production would require a volume of water up to 31% of dry season Mekong River flow to Vietnam. However, the two countries share an aquifer system in the Mekong Delta, where irrigation demand is increasingly met by groundwater. We estimate expansion rates of groundwater-irrigated land to be >10% per year in the Cambodian Delta using LANDSAT satellite data and simulate the effects of future expansion on groundwater levels over a 25-year period. If groundwater irrigation continues to expand at current rates, the water table will drop below the lift limit of suction pump wells, used for domestic supply by >1.5 million people, throughout much of the area within 15 years. Extensive groundwater irrigation jeopardizes access for shallow domestic water supply wells, raises the costs of pumping for all groundwater users, and may exacerbate arsenic contamination and land subsidence that are already widespread hazards in the region.

  2. Blood flukes (Digenea: Aporocotylidae) of walking catfishes (Siluriformes: Clariidae): new genus and species from the Mekong River (Vietnam) with comments on related catfish aporocotylids.

    Science.gov (United States)

    Truong, Triet Nhat; Bullard, Stephen A

    2013-07-01

    Nomasanguinicola canthoensis gen. et sp. n. infects the branchial vessels of bighead catfish, Clarias macrocephalus Günther (Siluriformes: Clariidae), in the Mekong River near Can Tho, southern Vietnam. Nomasanguinicola differs from all other genera of fish blood flukes (Digenea: Aporocotylidae) by the combination of lacking body spines and by having an anterior sucker with two flanking columns of large denticles, an intestine comprising several short papilla-like caeca, an inverse U-shaped uterus, and an ootype located near the separate genital pores. The new species has an ootype that is posterior to the level of the female genital pore. That feature most easily differentiates it from the only other putative aporocotylid species having an anterior sucker with two flanking columns of large denticles, Plehniella dentata Paperna, 1964 and Sanguinicola clarias Imam, Marzouk, Hassan et Itman, 1984, which have an ootype that is lateral (P. dentata) or anterior (S. clarias) to the level of the female genital pore. These two species apparently lack extant type materials, infect North African catfish, Clarias gariepinus (Burchell), and herein are considered incertae sedis, but likely comprise species of Nomasanguinicola. An updated list of hosts, sites of infection and geographic localities for the six species and three genera of blood flukes that mature in catfishes is provided. The new species is the first fish blood fluke recorded from Vietnam and only the third reported from a walking catfish (Clariidae).

  3. Descriptive results of a prospective cohort study of avian influenza in the Mekong River Delta of Viet Nam.

    Science.gov (United States)

    Nguyen, Long V; Stevenson, M; Schauer, B; Nguyen, D T; Tran, Q D; Tien, T N; Tran, P T T; Jones, G; Prattley, D; Morris, R

    2014-12-01

    A prospective cohort study of avian influenza infection in poultry flocks was carried out in the Mekong River Delta of Viet Nam between December 2008 and April 2010. Our objectives were to (i) estimate the prevalence and incidence of avian influenza virus infection and (ii) assess the efficacy of H5N1 vaccination programmes as indicated by the presence of H5 antibody in vaccinated and unvaccinated poultry. Real-time PCR and H5 multiplex assays were used to detect the antigen of avian influenza viruses from swab samples. The haemagglutination inhibition test was used to detect H5 antibody. A total of 17 968 swab and 14 878 blood samples were collected from 5476 birds over the study period. The overall incidence rate of influenza type A virus infection was 5 (95% CI 4-7) positive birds per 100 bird-months at risk. The overall incidence rate of H5 virus infection was 0.2 (95% CI 0.1-0.5) positive birds per 100 bird-months at risk. Fifty (95% CI 48-52) birds per 100 tested birds were H5 HI positive in the unvaccinated group compared with 71 (95% CI 69-73) birds per 100 in the vaccinated group. Influenza type A and H5 viruses were circulating in village poultry throughout the study period with no recorded signs of clinical disease. This implies that interventions need to be carried out continuously throughout the year rather than only focusing on the established high-risk periods. Broiler ducks had an incidence rate of influenza H5 virus infection approximately four times greater than that of layer ducks and in-contact species. We conclude that broiler ducks are likely to be the main entry route for H5 virus into poultry flocks in the MRD. Control efforts would benefit from understanding why there is a difference between villages in H5 incidence and developing strategies to provide greater protection to broiler ducks. © 2013 Blackwell Verlag GmbH.

  4. Groundwater arsenic in the Red River delta, Vietnam

    DEFF Research Database (Denmark)

    Jessen, Søren

    Afhandlingen omhandler problemerne med høje koncentrationer af arsen i grundvandet i Den Røde Flod deltaet (Vietnam), der bebos af omkring 11 millioner mennesker. Forgiftning med arsen fra grundvand brugt til drikkevand kan give alvorlige og ultimativt dødelige sygdomme. Afhandlingen beskriver...... hvorledes koncentrationen af arsen i grundvandet er styret af den geologiske dannelseshistorie. Denne viden er væsentlig i forbindelse med planlægningen af den indsats, der er nødvendig for at afhjælpe arsenproblemet i Den Røde Flod deltaet. I afhandlingen beskrives desuden de hydrogeologiske og geokemiske...... processer, der medfører forhøjede koncentrationer af arsen i grundvandet. Blandt forskere er der generelt udbredt enighed om, at kilden til arsen i grundvandet er naturlig, og at arsen sidder bundet til oxider af jern (rust-partikler) på sedimenter af ler og sand, der transporteres fra Himalaya og aflejres...

  5. Heritability and genotype by environment interaction estimates for harvest weight, growth rate, and shape of Nile tilapia (Oreochromis niloticus) grown in river cage and VAC in Vietnam

    NARCIS (Netherlands)

    Trong, T.Q.; Mulder, H.A.; Arendonk, van J.A.M.; Komen, J.

    2013-01-01

    Harvest weight has been the main selected trait for the GIFT strain of Nile tilapia (Oreochromis niloticus). However, growth rate and body shape are traits of increasing interest. In the Mekong Delta of Vietnam, intensive river-cage culture and low-input ponds are the most important production

  6. What controls the stable isotope composition of precipitation in the Mekong Delta? A model-based statistical approach

    Directory of Open Access Journals (Sweden)

    N. Le Duy

    2018-02-01

    Full Text Available This study analyzes the influence of local and regional climatic factors on the stable isotopic composition of rainfall in the Vietnamese Mekong Delta (VMD as part of the Asian monsoon region. It is based on 1.5 years of weekly rainfall samples. In the first step, the isotopic composition of the samples is analyzed by local meteoric water lines (LMWLs and single-factor linear correlations. Additionally, the contribution of several regional and local factors is quantified by multiple linear regression (MLR of all possible factor combinations and by relative importance analysis. This approach is novel for the interpretation of isotopic records and enables an objective quantification of the explained variance in isotopic records for individual factors. In this study, the local factors are extracted from local climate records, while the regional factors are derived from atmospheric backward trajectories of water particles. The regional factors, i.e., precipitation, temperature, relative humidity and the length of backward trajectories, are combined with equivalent local climatic parameters to explain the response variables δ18O, δ2H, and d-excess of precipitation at the station of measurement. The results indicate that (i MLR can better explain the isotopic variation in precipitation (R2  =  0.8 compared to single-factor linear regression (R2  =  0.3; (ii the isotopic variation in precipitation is controlled dominantly by regional moisture regimes (∼ 70 % compared to local climatic conditions (∼ 30 %; (iii the most important climatic parameter during the rainy season is the precipitation amount along the trajectories of air mass movement; (iv the influence of local precipitation amount and temperature is not significant during the rainy season, unlike the regional precipitation amount effect; (v secondary fractionation processes (e.g., sub-cloud evaporation can be identified through the d-excess and take

  7. What controls the stable isotope composition of precipitation in the Mekong Delta? A model-based statistical approach

    Science.gov (United States)

    Le Duy, Nguyen; Heidbüchel, Ingo; Meyer, Hanno; Merz, Bruno; Apel, Heiko

    2018-02-01

    This study analyzes the influence of local and regional climatic factors on the stable isotopic composition of rainfall in the Vietnamese Mekong Delta (VMD) as part of the Asian monsoon region. It is based on 1.5 years of weekly rainfall samples. In the first step, the isotopic composition of the samples is analyzed by local meteoric water lines (LMWLs) and single-factor linear correlations. Additionally, the contribution of several regional and local factors is quantified by multiple linear regression (MLR) of all possible factor combinations and by relative importance analysis. This approach is novel for the interpretation of isotopic records and enables an objective quantification of the explained variance in isotopic records for individual factors. In this study, the local factors are extracted from local climate records, while the regional factors are derived from atmospheric backward trajectories of water particles. The regional factors, i.e., precipitation, temperature, relative humidity and the length of backward trajectories, are combined with equivalent local climatic parameters to explain the response variables δ18O, δ2H, and d-excess of precipitation at the station of measurement. The results indicate that (i) MLR can better explain the isotopic variation in precipitation (R2 = 0.8) compared to single-factor linear regression (R2 = 0.3); (ii) the isotopic variation in precipitation is controlled dominantly by regional moisture regimes (˜ 70 %) compared to local climatic conditions (˜ 30 %); (iii) the most important climatic parameter during the rainy season is the precipitation amount along the trajectories of air mass movement; (iv) the influence of local precipitation amount and temperature is not significant during the rainy season, unlike the regional precipitation amount effect; (v) secondary fractionation processes (e.g., sub-cloud evaporation) can be identified through the d-excess and take place mainly in the dry season, either locally

  8. Effects of lead, molybdenum, rubidium, arsenic and organochlorines on spermatogenesis in fish: Monitoring at Mekong Delta area and in vitro experiment

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, Sonoko [Laboratory of Fish Reproductive Physiology, Ehime University, Matsuyama, Ehime 790-8566 (Japan); Miura, Chiemi [Laboratory of Fish Reproductive Physiology, Ehime University, Matsuyama, Ehime 790-8566 (Japan); Ito, Aki [Laboratory of Fish Reproductive Physiology, Ehime University, Matsuyama, Ehime 790-8566 (Japan); Agusa, Tetsuro [Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime 790-8577 (Japan); Iwata, Hisato [Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime 790-8577 (Japan); Tanabe, Shinsuke [Center for Marine Environmental Studies (CMES), Ehime University, Matsuyama, Ehime 790-8577 (Japan); Bui Cach Tuyen [Nong Lam University, Thu Duc Distr., Ho Chi Minh City (Viet Nam); Miura, Takeshi [Laboratory of Fish Reproductive Physiology, Ehime University, Matsuyama, Ehime 790-8566 (Japan)]. E-mail: miutake@agr.ehime-u.ac.jp

    2007-06-05

    To estimate the influence of water contaminants on fish reproduction in the Mekong Delta area, we sampled cultivated male catfish (Pangasianodon hypophthalmus), investigated testicular development, and measured persistent organic pollutants (POPs) and trace element levels in muscle and liver, respectively. Various testes sizes were observed although sampling took place during a short period. Histological analysis revealed that all developmental stages of germ cells were observed in catfish with large testis, whereas only necrotic spermatogonia but no other germ cells were observed in catfish with small testis. In small testis, furthermore, vacuolization and hypertrophy of Sertoli cells were observed. Measurement of POPs in muscle and trace elements in liver demonstrated that there were negative correlations between GSI and the concentrations of Pb, Mo, Rb and As. To clarify possible direct effects of Pb, Mo, Rb and As on spermatogenesis in fish, we investigated the effects of these trace elements on spermatogenesis using in vitro testicular organ culture of Japanese eel (Anguilla japonica). Treatment with each of the trace elements alone did not affect spermatogenesis. However, treatment with 10{sup -7} M of Pb, 10{sup -5} and 10{sup -4} M of Mo, 10{sup -5}-10{sup -3} M of Rb or 10{sup -5} M of As inhibited the spermatogenesis induced by 11-ketotestosterone (11KT). Furthermore, treatment with 10{sup -4} M of As in combination with 11KT caused necrosis of testicular fragments. Taken together, these results are consistent with the hypothesis that Pb, Mo, Rb and As can exert inhibitory effects on spermatogenesis in catfish inhabiting the Mekong Delta area.

  9. February 2012 workshop jumpstarts the Mekong Fish Monitoring Network

    Science.gov (United States)

    Andersen, Matthew E.; Ainsley, Shaara M.

    2012-01-01

    The Mekong River in Southeast Asia travels through a basin rich in natural resources. The river originates on the northern slope of the world's tallest mountains, the Himalaya Range, and then drops elevation quickly through steep mountain gorges, tumbling out of China into Myanmar (Burma) and the Lao People's Democratic Republic (Lao PDR). The precipitous terrain of Lao PDR and Thailand generates interest in the river and its tributaries for hydropower development. The terrain, soils, water, and climate make it one of the world's most biologically rich regions. The Mekong's bounty is again on display in the Mekong River Delta, where rice production has successfully been increased to high levels making Vietnam second only to Thailand as the world's largest rice exporters. At least 800 fish species contribute to the natural resource bounty of the Mekong River and are the basis for one of the world's most productive fisheries that provide the primary protein source to more than 50 million people. Against this backdrop of rich natural resources, the U.S. Geological Survey (USGS) is working with the consulting firm FISHBIO, colleagues from the international Delta Research and Global Observation Network (DRAGON) Institute, and a broad contingent of Southeast Asian representatives and partners from abroad to increase knowledge of the Mekong River fisheries and to develop the capacity of permanent residents to investigate and understand these fisheries resources. With the Lower Mekong Basin (LMB) region facing the likelihood of significant environmental changes as a result of both human activities and global climate change, enhancing environmental understanding is critical. To encourage cooperation among the LMB scientists and managers in the study of the Mekong River's fisheries, FISHBIO and the USGS, with generous support from the U.S. State Department, hosted a workshop in Phnom Penh, Cambodia, in February 2012. Workshop participants were from Lao PDR, Thailand

  10. Forecast Mekong 2012: Building scientific capacity

    Science.gov (United States)

    Stefanov, James E.

    2012-01-01

    In 2009, U.S. Secretary of State Hillary R. Clinton joined the Foreign Ministers of Cambodia, Laos, Thailand, and Vietnam in launching the Lower Mekong Initiative to enhance U.S. engagement with the countries of the Lower Mekong River Basin in the areas of environment, health, education, and infrastructure. The U.S. Geological Survey Forecast Mekong supports the Lower Mekong Initiative through a variety of activities. The principal objectives of Forecast Mekong include the following: * Build scientific capacity in the Lower Mekong Basin and promote cooperation and collaboration among scientists working in the region. * Provide data, information, and scientific models to help resource managers there make informed decisions. * Produce forecasting and visualization tools to support basin planning, including climate change adaptation. The focus of this product is Forecast Mekong accomplishments and current activities related to the development of scientific capacity at organizations and institutions in the region. Building on accomplishments in 2010 and 2011, Forecast Mekong continues to enhance scientific capacity in the Lower Mekong Basin with a suite of activities in 2012.

  11. Relationship of urinary arsenic metabolites to intake estimates in residents of the Red River Delta, Vietnam

    International Nuclear Information System (INIS)

    Agusa, Tetsuro; Kunito, Takashi; Minh, Tu Binh; Pham Thi Kim Trang; Iwata, Hisato; Pham Hung Viet; Tanabe, Shinsuke

    2009-01-01

    This study investigated the status of arsenic (As) exposure from groundwater and rice, and its methylation capacity in residents from the Red River Delta, Vietnam. Arsenic levels in groundwater ranged from <1.8 to 486 μg/L. Remarkably, 86% of groundwater samples exceeded WHO drinking water guideline of 10 μg/L. Also, estimated inorganic As intake from groundwater and rice were over Provisional Tolerable Weekly Intake (15 μg/week/kg body wt.) by FAO/WHO for 92% of the residents examined. Inorganic As and its metabolite (monomethylarsonic acid and dimethylarsinic acid) concentrations in human urine were positively correlated with estimated inorganic As intake. These results suggest that residents in these areas are exposed to As through consumption of groundwater and rice, and potential health risk of As is of great concern for these people. Urinary concentration ratios of dimethylarsinic acid to monomethylarsonic acid in children were higher than those in adults, especially among men, indicating greater As methylation capacity in children. - Positive correlations between estimated arsenic intake and urinary inorganic arsenic and its metabolites were observed in human from the Red River Delta, Vietnam

  12. Relationship of urinary arsenic metabolites to intake estimates in residents of the Red River Delta, Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Agusa, Tetsuro [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Department of Legal Medicine, Shimane University Faculty of Medicine, Enya 89-1, Izumo 693-8501 (Japan); Kunito, Takashi [Department of Environmental Sciences, Faculty of Science, Shinshu University, 3-1-1 Asahi, Matsumoto 390-8621 (Japan); Minh, Tu Binh [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Department of Biology and Chemistry (BCH), City University of Hong Kong, 83 Tat Chee Avenue, Kowloon Tong, Hong Kong (China); Pham Thi Kim Trang [Center for Environmental Technology and Sustainable Development (CETASD), Hanoi National University, 334 Nguyen Trai Street, Thanh Xuan, Hanoi (Viet Nam); Iwata, Hisato [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Pham Hung Viet [Center for Environmental Technology and Sustainable Development (CETASD), Hanoi National University, 334 Nguyen Trai Street, Thanh Xuan, Hanoi (Viet Nam); Tanabe, Shinsuke [Center for Marine Environmental Studies (CMES), Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan)], E-mail: shinsuke@agr.ehime-u.ac.jp

    2009-02-15

    This study investigated the status of arsenic (As) exposure from groundwater and rice, and its methylation capacity in residents from the Red River Delta, Vietnam. Arsenic levels in groundwater ranged from <1.8 to 486 {mu}g/L. Remarkably, 86% of groundwater samples exceeded WHO drinking water guideline of 10 {mu}g/L. Also, estimated inorganic As intake from groundwater and rice were over Provisional Tolerable Weekly Intake (15 {mu}g/week/kg body wt.) by FAO/WHO for 92% of the residents examined. Inorganic As and its metabolite (monomethylarsonic acid and dimethylarsinic acid) concentrations in human urine were positively correlated with estimated inorganic As intake. These results suggest that residents in these areas are exposed to As through consumption of groundwater and rice, and potential health risk of As is of great concern for these people. Urinary concentration ratios of dimethylarsinic acid to monomethylarsonic acid in children were higher than those in adults, especially among men, indicating greater As methylation capacity in children. - Positive correlations between estimated arsenic intake and urinary inorganic arsenic and its metabolites were observed in human from the Red River Delta, Vietnam.

  13. The systematics and independent evolution of cave ecomorphology in distantly related clades of Bent-toed Geckos (Genus Cyrtodactylus Gray, 1827) from the Mekong Delta and islands in the Gulf of Thailand.

    Science.gov (United States)

    Grismer, L Lee; Wood, P L Jr; Tri, Ngo Van; Murdoch, Matthew L

    2015-06-26

    An integrative taxonomic analysis of the distantly related Cyrtodactylus condorensis and intermedius species complexes of the Mekong Delta revealed that C. paradoxus is a junior synonym of C. condorensis and that C. thochuensis is a junior synonym of C. leegrismeri. Additionally, the analysis revealed that a cave-dwelling ecomorpholgy has evolved independently early on in the evolution of both complexes (represented by C. hontreensis in the intermedius complex and C. grismeri and C. eisenmani in the condorensis complex) and cave ecomorphs exist in sympatry-but not syntopy-with general scansorial ecomorphs. Multiple, recent, cyclical, glacioeustatic driven changes in sea levels across the Sunda Shelf are hypothesized to account for the evolution and distribution of the widely separated, conspecific insular populations of C. condorensis and C. leegrismeri. The independent evolution of cave ecomorphology is proposed to have been driven by competition avoidance. Habitat islands across the Mekong Delta are an important source of endemism and in need of protection.

  14. Patterns of fish diversity and assemblage structure and water quality in the longest Asian tropical river (Mekong)

    Science.gov (United States)

    Chea, R.; Lek, S.; Grenouillet, G.

    2016-12-01

    Although the Mekong River is one of the world's 35 biodiversity hotspots, the large-scale patterns of fish diversity and assemblage structure remain poorly addressed. The present study aimed to investigate the spatial variability of water quality in the Lower Mekong Basin and the fish distribution patterns in the Lower Mekong River (LMR) and to identify their environmental determinants. Daily fish catch data at 38 sites distributed along the LMR were related to 15 physicochemical and 19 climatic variables. As a result, four different clusters were defined according to the similarity in assemblage composition and 80 indicator species were identified. While fish species richness was highest in the Mekong delta and lowest in the upper part of the LMR, the diversity index was highest in the middle part of the LMR and lowest in the delta. We found that fish assemblages changed along the environmental gradients and that the main drivers affecting the fish assemblage structure were the seasonal variation of temperature, precipitation, dissolved oxygen, pH, and total phosphorus. Specifically, upstream assemblages were characterized by cyprinids and Pangasius catfish, well suited to low temperature, high dissolved oxygen and high pH. Fish assemblages in the delta were dominated by perch-like fish and clupeids, more tolerant to high temperatures, and high levels of nutrients (nitrates and total phosphorus) and salinity. Overall, the patterns were consistent between seasons. Our study contributes to establishing the first holistic fish community study in the LMR. Overall of the LMR water quality, we found that the water in the mainstream was less polluted than its tributaries; eutrophication and salinity could be key factors affecting water quality in LMR. Moreover, the seasonal variation of water quality seemed to be less marked than spatial variation occurring along the longitudinal gradient of Mekong River. Significant degradations were mainly associated with human

  15. A Probabilistic Typhoon Risk Model for Vietnam

    Science.gov (United States)

    Haseemkunju, A.; Smith, D. F.; Brolley, J. M.

    2017-12-01

    Annually, the coastal Provinces of low-lying Mekong River delta region in the southwest to the Red River Delta region in Northern Vietnam is exposed to severe wind and flood risk from landfalling typhoons. On average, about two to three tropical cyclones with a maximum sustained wind speed of >=34 knots make landfall along the Vietnam coast. Recently, Typhoon Wutip (2013) crossed Central Vietnam as a category 2 typhoon causing significant damage to properties. As tropical cyclone risk is expected to increase with increase in exposure and population growth along the coastal Provinces of Vietnam, insurance/reinsurance, and capital markets need a comprehensive probabilistic model to assess typhoon risk in Vietnam. In 2017, CoreLogic has expanded the geographical coverage of its basin-wide Western North Pacific probabilistic typhoon risk model to estimate the economic and insured losses from landfalling and by-passing tropical cyclones in Vietnam. The updated model is based on 71 years (1945-2015) of typhoon best-track data and 10,000 years of a basin-wide simulated stochastic tracks covering eight countries including Vietnam. The model is capable of estimating damage from wind, storm surge and rainfall flooding using vulnerability models, which relate typhoon hazard to building damageability. The hazard and loss models are validated against past historical typhoons affecting Vietnam. Notable typhoons causing significant damage in Vietnam are Lola (1993), Frankie (1996), Xangsane (2006), and Ketsana (2009). The central and northern coastal provinces of Vietnam are more vulnerable to wind and flood hazard, while typhoon risk in the southern provinces are relatively low.

  16. Future hydrological alterations in the Mekong Delta under the impact of water resources development, land subsidence and sea level rise

    Directory of Open Access Journals (Sweden)

    Thanh Duc Dang

    2018-02-01

    New hydrological insights for the region: Depending on hydrological characteristics of each region (river-dominated, transitional or tidal, the influence of each potential driver may vary. The operation of proposed hydropower dams would change river-dominated upper floodplain’s water levels by 26 to 70% and −0.8 to −5.9% in the dry and wet season respectively, but the impact diminishes throughout the floodplains. In the wet season, the upper Vietnamese Delta changes from a transitional stage to a river-dominated stage, and localized water infrastructure development in the upper delta has the greatest effect on water levels in the region. Land subsidence combined with sea level rise could have the greatest future influence on flooding in the delta if current rates are extrapolated. Sustainable water management strategies are thus necessary to mitigate changes in the floodplains and delta and increase resilience to sea level rise and land subsidence.

  17. Vietnam

    International Nuclear Information System (INIS)

    2001-12-01

    This document presents the energy profile of Vietnam: energy organizations and policy; companies: Petrovietnam (oil), Vietgas (gas), Power Company 1, 2 and 3 (PC1, PC2, PC3) and Electricite du Vietnam (electric power), Vinacoal (coal); supplies (resources, electric power, oil, gas and coal); prices; consumption; projects and perspectives. (J.S.)

  18. Vietnam

    International Development Research Centre (IDRC) Digital Library (Canada)

    Cathy Egan

    taken with the eager collaboration of Vietnam's government, have since ... social sciences; and environment and natural resource management) was ... deliberate and increasing openness to the world of trade, investment, and knowl- edge ... Vietnam design trade liberalization and competition policies (in part as preparation.

  19. Chiny w hydropolityce regionu rzeki Mekong

    Directory of Open Access Journals (Sweden)

    Michał Zaręba

    2017-03-01

    Full Text Available The Mekong is a transboundary river chich runs through China, Myanmar, Thailand, Laos, Cambodia, and Vietnam. Its basin, where more than 70 mln people live, creates the lar gest inland fishery and comprises a main skurce of fresh water, also used in agriculture. But the most tempting is its hydropower potential which has been developed especially by China. The growing number of hydropower plants In the upper stretch poses a real threat for Lower Mekong basin countries. This article examines the role of China in the Mekong region and analyzes relations over the water resources between the Middle Kingdom and other riparian states. Paper indicates the main purposes of China’s hydropolitics of the Mekong river basin, its hydropolitical strategy towards this region and gives an answer whether China wants to cooperate or develop its hydropower potential regardless of consequences for Indochinese states and possible conflicts.

  20. Detection of potentially novel paramyxovirus and coronavirus viral RNA in bats and rats in the Mekong Delta region of southern Viet Nam.

    Science.gov (United States)

    Berto, A; Anh, P H; Carrique-Mas, J J; Simmonds, P; Van Cuong, N; Tue, N T; Van Dung, N; Woolhouse, M E; Smith, I; Marsh, G A; Bryant, J E; Thwaites, G E; Baker, S; Rabaa, M A

    2018-02-01

    Bats and rodents are being increasingly recognized as reservoirs of emerging zoonotic viruses. Various studies have investigated bat viruses in tropical regions, but to date there are no data regarding viruses with zoonotic potential that circulate in bat and rat populations in Viet Nam. To address this paucity of data, we sampled three bat farms and three wet markets trading in rat meat in the Mekong Delta region of southern Viet Nam. Faecal and urine samples were screened for the presence of RNA from paramyxoviruses, coronaviruses and filoviruses. Paramyxovirus RNA was detected in 4 of 248 (1%) and 11 of 222 (4.9%) bat faecal and urine samples, respectively. Coronavirus RNA was detected in 55 of 248 (22%) of bat faecal samples; filovirus RNA was not detected in any of the bat samples. Further, coronavirus RNA was detected in 12 of 270 (4.4%) of rat faecal samples; all samples tested negative for paramyxovirus. Phylogenetic analysis revealed that the bat paramyxoviruses and bat and rat coronaviruses were related to viruses circulating in bat and rodent populations globally, but showed no cross-species mixing of viruses between bat and rat populations within Viet Nam. Our study shows that potentially novel variants of paramyxoviruses and coronaviruses commonly circulate in bat and rat populations in Viet Nam. Further characterization of the viruses and additional human and animal surveillance is required to evaluate the likelihood of viral spillover and to assess whether these viruses pose a risk to human health. © 2017 The Authors. Zoonoses and Public Health Published by Blackwell Verlag GmbH.

  1. Comparison of partial and complete soil K budgets under intensive rice cropping in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Hoa, N.M.; Janssen, B.H.; Oenema, O.; Dobermann, A.

    2006-01-01

    Crop response to added fertilizer K was often found to be small in trials conducted on favorable soils of tropical rice ecosystems. Hence, applications of only fertilizer N and P were recommended. This has resulted in soil K mining in intensive cropping systems in China, India and other Asian

  2. Application of co-anaerobic digester's effluent for sustainable agriculture and aquaculture in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Nguyen, V C N; Fricke, K

    2015-01-01

    This investigation studied the application of digester effluent from co-digestion of pig manure and spent mushroom substrate as a fertilizer for leaf mustard planting and as feed for Tilapia fish growing. The fish raising experiment was set up in 1 × 1 × 1 m hapa conditions (triplicate for each treatment) with the density of 10 individiual per hapa; the fish weight and length were measured every 10 days for 50 continuous days. The leaf mustard was planted in real conditions at farmer's garden with normal cultivation style, and the weight and length of the plant were measured four times during the growing period. The study result shows that the harvest yield of leaf mustard fertilized by the digester effluent was 5.4 times higher than that by an inorganic fertilizer (IF). In addition to its contribution to a higher yield, the digester effluent accelerated the flower formation and shortened cultivation duration. For Tilapia fish culture, the growing rate of fish in the treatments supplied with 50% digester effluent + 50% commercial food (CF) was not significantly different in comparison to the fish cultivation with 100% CF. The result strongly confirms that the digester effluent from a co-digestion biogas plant of pig dung and spent mushroom compost is possible to be used as an organic fertilizer well for not only vegetable planting but also fish culture.

  3. Ecological risk assessment of the antibiotic enrofloxacin applied to Pangasius catfish farms in the Mekong delta, Vietnam

    NARCIS (Netherlands)

    Rico Artero, A.; Phu, T.M.; Huong, D.T.T.; Phuong, N.T.; Brink, van den P.J.

    2015-01-01

    Antibiotics applied in aquaculture production may be released into the environment and contribute to the deterioration of surrounding aquatic ecosystems. In the present study, we assessed the ecological risks posed by the use of the antibiotic enrofloxacin (ENR), and its main metabolite

  4. Application of GIS in land-use planning, a case study in the coastal Mekong Delta of Vietnam

    NARCIS (Netherlands)

    Trung, N.H.; Quang Tri, Le; Mensvoort, van M.E.F.; Bregt, A.K.

    2006-01-01

    This paper presents the applications of Geoinformatics System (GIS) in three different land-use planning (LUP) approaches. The participatory LUP (PLUP) which strongly consider the local people perceptions for land utilizations, the guidelines for LUP by FAO enhanced with multi-criteria evaluation

  5. Application of GIS in land-use planning: a case study in the Coastal Mekong Delta of Vietnam

    NARCIS (Netherlands)

    Trung, N.H.; Quang Tri, Le; Mensvoort, van M.E.F.; Bregt, A.K.

    2007-01-01

    This paper presents the applications of Geographic Information System (GIS) in three different Land Use Planning (LUP) approaches: The participatory LUP (PLUP) which strongly considers the local people perceptions for land utilizations, the guidelines for LUP by FAO enhanced with multi-criteria

  6. Vietnam

    International Nuclear Information System (INIS)

    2004-02-01

    This document summarizes the main energy facts and data about Vietnam: institutions and energy policy, energy companies (Petrovietnam (oil), Vietgas (gas), Electricity of Vietnam (EVN), Vinacoal (coal)), energy production (resources, electricity, oil, natural gas, coal), energy prices (motor fuels and electricity), energy consumption, and future energy issues and prospects (exploitation of new fossil fuel resources, building of new refineries and power stations). The main economic, supply and demand, and energy balance indicators are summarized in tables and graphics. (J.S.)

  7. Efficiency of Different Integrated Agriculture Aquaculture Systems in the Red River Delta of Vietnam

    Directory of Open Access Journals (Sweden)

    Nguyen Van Huong

    2018-02-01

    Full Text Available Integrated Agriculture Aquaculture (IAA is characteristic with diversity of small-scale production systems in the Red River Delta, Vietnam where most integrated aquaculture systems are closely associated to the VAC model, an ecosystem production that three components: garden (V, pond (A and livestock pen (C are integrated. These VAC systems effectively use all the available land, air, water and solar energy resources, and also effectively recycle by-products and waste for providing diversified agricultural products to meet the complex nutritional demands of rural communities. The IAA systems are dynamic, diverse and subject to economic and environmental changes. By investigating 167 aquaculture households, the traditional VAC, New VAC, Animal Fish (AF and Commercial Fish (FS systems are identified as four existing IAA systems. This paper presents the main characteristics and economic efficiency of these IAA systems. The study’s results indicate clear evidence that the traditional VAC system and New VAC system are the most efficient and effective models. The findings of this study have shed light on the important role of integrated aquaculture systems to food security and economic development of households and local communities. The VAC systems are likely to propose for improving household food security and developing the local economy.

  8. Social and ecological challenges of market-oriented shrimp farming in Vietnam.

    Science.gov (United States)

    Lan, Ngo Thi Phuong

    2013-01-01

    Vietnam is one of the largest shrimp exporters in the world. Since 2010, Vietnam has earned about two billion dollars annually through shrimp exports. As a fertile area of greatest potential for agricultural production in Vietnam, the Mekong Delta has been a major contributor to the country's achievements, especially in the agricultural sector. During recent decades, trade liberation along with various policies in support of aquaculture has accelerated the development of shrimp production in the Delta. Based on an ethnographic study of shrimp farming in the Mekong Delta of Vietnam, I assert that along with great rewards arising from the expansion of shrimp farming areas, productivity, and export value, the shrimp industry has brought various environmental, economic and social challenges. Consequently, shrimp farming is a risky business and local inhabitants have relied on various strategies to cope with these challenges. Risk mitigation in shrimp production and labor migration are the two important strategies of local inhabitants for securing their livelihoods. Water pollution and poor quality post-larvae shrimp are direct consequences of market-oriented production.

  9. Vietnam.

    Science.gov (United States)

    1984-05-01

    Attention in this discussion of Vietnam is directed to the following: people; geography; history; government; the economy (agriculture and industry, trade and balance of payments); foreign relations; and relations between the US and Vietnam. In mid-1983 the population was estimated at 57,610,000 with an annual growth rate of 2.4%. Ethnic Vietnamese constitute almost 90% of the population. Various ethnic groups make up the remaining 10% of the population, with approximately 1.2 million Chinese being the most numerous and concentrated in southern Vietnam. The 2nd largest minority, the Montagnards (mountain tribesmen) comprise 2 main ethnolinguistic groups--Malayo Polynesia and Mon-Khmer. The most important political institution in Vietnam is the Vietnamese Communisty Party. All but 4 party Politburo members concurrently hold high positions in the government. The most important powers within the Vietnamese government, as opposed to the Communisty Party, are the executive agencies. Under the overly ambitious initial 5 year plan and the more conservative 1981-85 plan, the Vietnamese have made little progress in raising output and living standards beyond the levels of the 1960s. Guidelines of the 1981-85 plan call for attaining food self sufficiency, strengthening export and consumer industries, as well as the heavy industries that support them, and improving transport and energy production. The US does not have diplomatic relations with Vietnam.

  10. Hydrological and Mineralogical Factors Influencing Paradoxical Groundwater Arsenic Release in the Red River Delta, Vietnam

    Science.gov (United States)

    Nghiem, A.; Bostick, B. C.

    2017-12-01

    In South and Southeast Asia, the widespread contamination of groundwater arsenic (As) via microbial reduction of As-bearing iron (Fe) minerals in the subsurface results in toxic levels of arsenic above the World Health Organization (WHO) drinking water standard of 10 ug/L. High groundwater arsenic levels are generally found in gray Holocene aquifers whereas orange-sanded Pleistocene aquifers are typically a safer, lower As alternative. In the Red River Delta of Vietnam and elsewhere, Pleistocene aquifers can also have elevated arsenic levels, often due to increased groundwater pumping from the growing Hanoi area drawing high As water from Holocene aquifers, or from reduction induced by advected groundwater and organic carbon from the Red River. To determine which factors threaten the Pleistocene aquifers, we critically examine the hydrological and geochemical factors that could influence arsenic levels in the area. Exploiting an asymmetry in the region just south of Hanoi, yearlong spatiotemporal measurements of dissolved arsenic levels reveals a paradox between a Pleistocene aquifer site in Yen My (west bank) with higher As concentrations than a Holocene site in Van Duc (east bank). We monitor the influence of local and regional hydrology via water table measurements, stable water isotopes and conservative anion concentrations linked to the release of aqueous As. Preliminary x-ray absorption spectroscopy (XAS) data point to As(V)/arsenic sulfide minerals in Yen My versus As(III) minerals in Van Duc. Coupled to hydrology, downcore Fe Extended X-Ray Absorption Fine Structure (EXAFS) and As X-ray Absorption Near Edge Structure (XANES) stratigraphy and spatiotemporal dissolved organic carbon data serve to narrow down the possible sources of carbon and reductive processes that affect As speciation and transport. Overall, understanding sources that endanger the Pleistocene aquifers may elucidate important As cycling mechanisms at play that threatens water quality for

  11. Risks of Coastal Storm Surge and the Effect of Sea Level Rise in the Red River Delta, Vietnam

    OpenAIRE

    Neumann, James; Ludwig, Lindsay; Verly, Caroleen; Emanuel, Kerry Andrew; Ravela, Srinivas

    2015-01-01

    This paper considers the impact of sea level rise and storm surge on the Red River delta region of Vietnam an area already known to be highly vulnerable to coastal risks. By combining a range of sea level rise scenarios for 2050 with the simulated storm surge level for the 100-year storm surge, we analyze permanently inundated lands and temporary flood zones. As is well-established in the literature, sea level rise will increase the risk of storms by raising the base sea level from which surg...

  12. Governance of ‘long term delta planning’ in Bangladesh, Vietnam and the Netherlands

    NARCIS (Netherlands)

    Staveren, van M.F.

    2014-01-01

    The Deltas in Times of Climate Change Conference II, taking place in September 2014, Rotterdam, presented a suitable occasion to discuss both delta challenges and interesting approaches to how ‘delta dynamics’ are being dealt with worldwide.1 Delta dynamics include here both environmental (including

  13. Response in the mekong deltaic coast to its changing sediment sources and sinks

    NARCIS (Netherlands)

    Phan, M.H.; Reniers, A.J.H.M.; Ye, Q.; Stive, M.J.F.; Aagaard, T.; Deigaard, R.; Fuhrman, D.

    2017-01-01

    The coastal zone of Mekong delta is suffering under intense pressures from climate change as well as human intervention. Currently, the coastline evolution of Mekong delta is a complex combination of impacts due to (1) relative sea level rise i.e. the sum of eustatic sea level rise, natural and

  14. Agricultural innovation : multiple grounds for technology policies in the Red River Delta of Vietnam

    NARCIS (Netherlands)

    Nguyen Van Linh,

    2001-01-01

    Food security, a lingering concern although is not as critical as in the past, remains one of the most important strategies for agricultural development in Vietnam. In conjunction with this strategy, productivity is very much a concern of the government. However, growth in agricultural

  15. Risks of Coastal Storm Surge and the Effect of Sea Level Rise in the Red River Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    James E. Neumann

    2015-05-01

    Full Text Available This paper considers the impact of sea level rise and storm surge on the Red River delta region of Vietnam. Permanently inundated lands and temporary flood zones are analyzed by combining sea level rise scenarios for 2050 with simulated storm surge levels for the 100-year event. Our analysis finds that sea level rise through 2050 could increase the effective frequency of the current 100-year storm surge, which is associated with a storm surge of roughly five meters, to once every 49 years. Approximately 10% of the Hanoi region’s GDP is vulnerable to permanent inundation due to sea level rise, and more than 40% is vulnerable to periodic storm surge damage consistent with the current 100-year storm. We conclude that coastal adaptation measures, such as a planned retreat from the sea, and construction of a more substantial seawall and dike system, are needed to respond to these threats.

  16. Pesticides in soil and sediment of a dyke-protected area of the Red River Delta, Vietnam

    Science.gov (United States)

    Braun, Gianna; Bläsing, Melanie; Kruse, Jens; Amelung, Wulf; Renaud, Fabrice; Sebesvari, Zita

    2017-04-01

    Coastal regions are densely populated but at the same time represent important agricultural areas for food production of the growing world population. To sustain high agricultural yields, in monocultures such as permanent rice systems, pesticides are used in high quantity and frequency. While earlier studies monitored the fate of pesticides in paddy rice systems, the overall fate of these compounds is altered nowadays due to the construction of dykes, which are needed in many delta regions to protect them from high tides, storm surges and salt water intrusion such as in the Red River Delta. The dyke system regulates the discharge and water exchange inside the diked area including irrigation channels for the paddy rice production. Local authorities observed increasing pollution towards the sea (highest pollution close to the dykes) and hypothesized that the dyke system would prevent water exchange and thus lead to an accumulation of pollutants within the diked area. Hence, the purpose of this study was to investigate the effect of dykes on pesticide pollution patterns in coastal delta regions of the Red River Delta. The study was conducted in the district Giao Thuy of the Red River Delta, Vietnam. This area is surrounded by a sea and river dyke; both have several inlet and outlet gates to control the water level in the irrigation channels. We determined the pesticide pollution pattern in a diked agricultural area, as well as along salinity gradients in and outside the diked areas. Samples were taken from rice fields and sediments from irrigation channels inside the diked area as well from saline aquaculture fields located outside the dyke. Pesticide analysis was conducted by accelerated solvent extraction (ASE), followed up by the clean-up process described by Laabs et al. (2007) and analyses using gas chromatography coupled with a mass selective detector (MSD). Preliminary results suggest that out of the 26 analysed compounds chlorpyrifos, propiconazole and

  17. Genetic polymorphisms in AS3MT and arsenic metabolism in residents of the Red River Delta, Vietnam

    International Nuclear Information System (INIS)

    Agusa, Tetsuro; Iwata, Hisato; Fujihara, Junko; Kunito, Takashi; Takeshita, Haruo; Minh, Tu Binh; Trang, Pham Thi Kim; Viet, Pham Hung; Tanabe, Shinsuke

    2009-01-01

    To elucidate the role of genetic factors in arsenic (As) metabolism, we studied associations of single nucleotide polymorphisms (SNPs) in As (+ 3 oxidation state) methyltransferase (AS3MT) with the As concentrations in hair and urine, and urinary As profile in residents in the Red River Delta, Vietnam. Concentrations of total As in groundwater were 0.7-502 μg/l. Total As levels in groundwater drastically decreased by using sand filter, indicating that the filter could be effective to remove As from raw groundwater. Concentrations of inorganic As (IAs) in urine and total As in hair of males were higher than those of females. A significant positive correlation between monomethylarsonic acid (MMA)/IAs and age in females indicates that older females have higher methylation capacity from IAs to MMA. Body mass index negatively correlated with urinary As concentrations in males. Homozygote for SNPs 4602AA, 35991GG, and 37853GG, which showed strong linkage disequilibrium (LD), had higher percentage (%) of dimethylarsinic acid (DMA) in urine. SNPs 4740 and 12590 had strong LD and associated with urinary %DMA. Although SNPs 6144, 12390, 14215, and 35587 comprised LD cluster, homozygotes in SNPs 12390GG and 35587CC had lower DMA/MMA in urine, suggesting low methylation capacity from MMA to DMA in homo types for these SNPs. SNPs 5913 and 8973 correlated with %MMA and %DMA, respectively. Heterozygote for SNP 14458TC had higher MMA/IAs in urine than TT homozygote, indicating that the heterozygote may have stronger methylation ability of IAs. To our knowledge, this is the first study on the association of genetic factors with As metabolism in Vietnamese.

  18. Genetic polymorphisms in glutathione S-transferase (GST) superfamily and arsenic metabolism in residents of the Red River Delta, Vietnam

    International Nuclear Information System (INIS)

    Agusa, Tetsuro; Iwata, Hisato; Fujihara, Junko; Kunito, Takashi; Takeshita, Haruo; Tu Binh Minh; Pham Thi Kim Trang; Pham Hung Viet; Tanabe, Shinsuke

    2010-01-01

    To elucidate the role of genetic factors in arsenic metabolism, we investigated associations of genetic polymorphisms in the members of glutathione S-transferase (GST) superfamily with the arsenic concentrations in hair and urine, and urinary arsenic profile in residents in the Red River Delta, Vietnam. Genotyping was conducted for GST ω1 (GSTO1) Ala140Asp, Glu155del, Glu208Lys, Thr217Asn, and Ala236Val, GST ω2 (GSTO2) Asn142Asp, GST π1 (GSTP1) Ile105Val, GST μ1 (GSTM1) wild/null, and GST θ1 (GSTT1) wild/null. There were no mutation alleles for GSTO1 Glu208Lys, Thr217Asn, and Ala236Val in this population. GSTO1 Glu155del hetero type showed higher urinary concentration of As V than the wild homo type. Higher percentage of DMA V in urine of GSTM1 wild type was observed compared with that of the null type. Strong correlations between GSTP1 Ile105Val and arsenic exposure level and profile were observed in this study. Especially, heterozygote of GSTP1 Ile105Val had a higher metabolic capacity from inorganic arsenic to monomethyl arsenic, while the opposite trend was observed for ability of metabolism from As V to As III . Furthermore, other factors including sex, age, body mass index, arsenic level in drinking water, and genotypes of As (+ 3 oxidation state) methyltransferase (AS3MT) were also significantly co-associated with arsenic level and profile in the Vietnamese. To our knowledge, this is the first study indicating the associations of genetic factors of GST superfamily with arsenic metabolism in a Vietnamese population.

  19. Mangrove conservation or shrimp farmer’s livelihood? The devolution of forest management and benefit sharing in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Tran Thi Thu Ha, Ha; Dijk, van H.; Bush, S.R.

    2012-01-01

    Large parts of the world's remaining mangrove forest are lost due to the expansion of shrimp farming in coastal areas. Current forest allocation and subcontracting policies of the Vietnamese government with respect to the devolution of forest management and participation of local people in

  20. Clustering of Beijing genotype Mycobacterium tuberculosis isolates from the Mekong delta in Vietnam on the basis of variable number of tandem repeat versus restriction fragment length polymorphism typing.

    NARCIS (Netherlands)

    Huyen, M.N.; Kremer, K.; Lan, N.T.; Buu, T.N.; Cobelens, F.G.; Tiemersma, E.W.; Haas, P. de; Soolingen, D. van

    2013-01-01

    BACKGROUND: In comparison to restriction fragment length polymorphism (RFLP) typing, variable number of tandem repeat (VNTR) typing is easier to perform, faster and yields results in a simple, numerical format. Therefore, this technique has gained recognition as the new international gold standard

  1. Clustering of Beijing genotype Mycobacterium tuberculosis isolates from the Mekong delta in Vietnam on the basis of variable number of tandem repeat versus restriction fragment length polymorphism typing

    NARCIS (Netherlands)

    Huyen, Mai N. T.; Kremer, Kristin; Lan, Nguyen T. N.; Buu, Tran N.; Cobelens, Frank G. J.; Tiemersma, Edine W.; de Haas, Petra; van Soolingen, Dick

    2013-01-01

    In comparison to restriction fragment length polymorphism (RFLP) typing, variable number of tandem repeat (VNTR) typing is easier to perform, faster and yields results in a simple, numerical format. Therefore, this technique has gained recognition as the new international gold standard in typing of

  2. An evaluation of fish health-management practices and occupational health hazards associated with Pangasius catfish (Pangasianodon hypophthalmus) aquaculture in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Phu, TranMinh; Nguyen Thanh, Phuong; Dung, Tu Thanh

    2016-01-01

    released antimicrobials and resistance development. Small-scale farmers were at particular occupational health risks when handling antimicrobials and other chemicals, e.g. mixing medicated feed with bare hands. There is an urgent need to improve knowledge and use innovative approaches, e.g. private......-public partnerships, to assure a prudent use of chemicals, to improve capacity and access to disease diagnosis, particularly for small-scale grow-out farmers and nurseries. Efforts to control use of antimicrobials in aquaculture should be coordinated with the livestock and human health sectors taking an One-Health...

  3. Recent social and biogeophysical changes in the Ganges-Brahmaputra-Meghna, Mekong, and Amazon deltas as inputs into evolutionary policy-making.

    Science.gov (United States)

    de Araujo Barbosa, C. C.; Hossain, S.; Szabo, S.; Matthews, Z.; Heard, S.; Dearing, J.

    2014-12-01

    Policy-making in social-ecological systems increasingly looks to iterative, evolutionary approaches that can address the inherent complexity of interactions between human wellbeing, agricultural and aquacultural production, and ecosystem services. Here we show how an analysis of available time-series in delta regions over past decades can provide important insight into the social-ecological system dynamics that result from the complexity. The presentation summarises the recent changes for major elements of each social-ecological system, for example demography, economy, health, climate, food, and water. Time-series data from official statistics, monitoring programmes and sequential satellite imagery are analysed to define the range of trends, the presence of change points, slow and fast variables, and the significant drivers of change. For example, in the Bangladesh delta zone, increasing gross domestic product and per capita income levels since the 1980s mirror rising levels of food and inland fish production. In contrast, non-food ecosystem services such as water availability, water quality and land stability have deteriorated. As a result, poverty alleviation is associated with environmental degradation. Trends in indicators of human wellbeing and ecosystem services point to widespread non-stationary dynamics governed by slowly changing variables with increased probability of systemic threshold changes/tipping points in the near future. We conclude by examining how the findings could feed into new management tools, such as system dynamic models and assessments of safe operating spaces. Such tools have the potential to help create policies that deliver alternative and sustainable paths for land management while accommodating social and environmental change.

  4. Origin and availability of organic matter leading to arsenic mobilisation in aquifers of the Red River Delta, Vietnam

    International Nuclear Information System (INIS)

    Eiche, Elisabeth; Berg, Michael; Hönig, Sarah-Madeleine; Neumann, Thomas; Lan, Vi Mai; Pham, Thi Kim Trang; Pham, Hung Viet

    2017-01-01

    Groundwater arsenic (As) concentrations in the Red River Delta (Vietnam) are often patchy and related to the microbially induced reduction of Fe oxy-hydroxides. In this study, we explored the influence of the origin, composition and availability of natural organic matter on the hydrochemical variability in the aquifers of Van Phuc. Carbon isotope signatures (δ"1"3C_o_r_g) and C/N ratios were assessed in combination with lithology, geochemistry, hydrochemistry, hydrology and the distribution of specific biomarkers. The elationship of C/N ratios and δ"1"3C_o_r_g distinguished four groups of sediment types that differ in their organic carbon sources. This includes organic carbon originating predominantly from vascular C_3 plants (C/N: 15.4–21.0, δ"1"3C_o_r_g: −28.6 to −26.7‰), C_4 plants (C/N: 10.6; δ"1"3C_o_r_g: −14.8‰), freshwater derived particulate organic carbon (C/N: ≤8; δ"1"3C_o_r_g:≤−24‰) as well as mixtures incorporating both sources. At the high As sites, we found particulate organic carbon (POC) being 1–2‰ less depleted in δ"1"3C_o_r_g than at low As sites. More importantly, however, our assessment shows that, the availability of organic matter has to be considered decisive with regard to groundwater As contamination. Fine-grained clayey sediments overlaying sands generally protect organic matter from substantial degradation and its leaching into an adjacent aquifer. However, at the sites that are high in dissolved As in Van Phuc, sediment layers rich in organic matter are hydraulically connected to the underlying aquifer. Here, soluble organic matter seeping into the aquifer can induce and/or enhance reducing conditions, thereby mobilising As from Fe oxy-hydroxides. Our study shows that both the clay content as well as the origin of organic matter are largely controlled by the depositional environment of the sediments. - Highlights: • Particulate organic carbon (POC) from C_3/C_4 plants and freshwater is a main source of

  5. Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis fruits in Vietnam.

    Directory of Open Access Journals (Sweden)

    Ivana Puglisi

    Full Text Available Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis, a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana rootstocks grafted with 'King' mandarin (Citrus nobilis and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch's postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi, sweet orange (Citrus x sinensis and bergamot (Citrus x bergamia as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on 'Carrizo' citrange (C. sinensis 'Washington Navel' x Poncirus trifoliata. This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity.

  6. Two previously unknown Phytophthora species associated with brown rot of Pomelo (Citrus grandis) fruits in Vietnam.

    Science.gov (United States)

    Puglisi, Ivana; De Patrizio, Alessandro; Schena, Leonardo; Jung, Thomas; Evoli, Maria; Pane, Antonella; Van Hoa, Nguyen; Van Tri, Mai; Wright, Sandra; Ramstedt, Mauritz; Olsson, Christer; Faedda, Roberto; Magnano di San Lio, Gaetano; Cacciola, Santa Olga

    2017-01-01

    Two distinct Phytophthora taxa were found to be associated with brown rot of pomelo (Citrus grandis), a new disease of this ancestral Citrus species, in the Vinh Long province, Mekong River Delta area, southern Vietnam. On the basis of morphological characters and using the ITS1-5.8S-ITS2 region of the rDNA and the cytochrome oxidase subunit 1 (COI) as barcode genes, one of the two taxa was provisionally named as Phytophthora sp. prodigiosa, being closely related to but distinct from P. insolita, a species in Phytophthora Clade 9, while the other one, was closely related to but distinct from the Clade 2 species P. meadii and was informally designated as Phytophthora sp. mekongensis. Isolates of P. sp. prodigiosa and P. sp. mekongensis were also obtained from necrotic fibrous roots of Volkamer lemon (C. volkameriana) rootstocks grafted with 'King' mandarin (Citrus nobilis) and from trees of pomelo, respectively, in other provinces of the Mekong River Delta, indicating a widespread occurrence of both Phytophthora species in this citrus-growing area. Koch's postulates were fulfilled via pathogenicity tests on fruits of various Citrus species, including pomelo, grapefruit (Citrus x paradisi), sweet orange (Citrus x sinensis) and bergamot (Citrus x bergamia) as well as on the rootstock of 2-year-old trees of pomelo and sweet orange on 'Carrizo' citrange (C. sinensis 'Washington Navel' x Poncirus trifoliata). This is the first report of a Phytophthora species from Clade 2 other than P. citricola and P. citrophthora as causal agent of fruit brown rot of Citrus worldwide and the first report of P. insolita complex in Vietnam. Results indicate that likely Vietnam is still an unexplored reservoir of Phytophthora diversity.

  7. Large-Scale Land Concessions, Migration, and Land Use: The Paradox of Industrial Estates in the Red River Delta of Vietnam and Rubber Plantations of Northeast Cambodia

    Directory of Open Access Journals (Sweden)

    Jefferson Fox

    2018-06-01

    Full Text Available This study investigated the implications of large-scale land concessions in the Red River Delta, Vietnam, and Northeast Cambodia with regard to urban and agricultural frontiers, agrarian transitions, migration, and places from which the migrant workers originated. Field interviews conducted near large-scale land concessions for industrial estates in the Red River Delta and rubber plantations in Northeast Cambodia suggest that these radically different concessions are paradoxically leading to similar reconfigurations of livelihoods, labor patterns, and landscapes despite basic differences in these forms of land use. Both the Red River Delta and Northeast Cambodia are frontier environments undergoing extensive agrarian change with migration to work in the large-scale land concessions leading to a shortage of farm labor that anticipates changes in farming practices and farm livelihoods. These population movements will lead to further land-use changes as governments invest in the infrastructure and services needed to support increased population density in the receiving areas. In addition, labor migrations associated with these investments affect land-use practices both at the site of the concession and the places from where the migrants originate.

  8. Estimation of Radionuclide Concentrations and Average Annual Committed Effective Dose due to Ingestion for the Population in the Red River Delta, Vietnam.

    Science.gov (United States)

    Van, Tran Thi; Bat, Luu Tam; Nhan, Dang Duc; Quang, Nguyen Hao; Cam, Bui Duy; Hung, Luu Viet

    2018-02-16

    Radioactivity concentrations of nuclides of the 232 Th and 238 U radioactive chains and 40 K, 90 Sr, 137 Cs, and 239+240 Pu were surveyed for raw and cooked food of the population in the Red River delta region, Vietnam, using α-, γ-spectrometry, and liquid scintillation counting techniques. The concentration of 40 K in the cooked food was the highest compared to those of other radionuclides ranging from (23 ± 5) (rice) to (347 ± 50) Bq kg -1 dw (tofu). The 210 Po concentration in the cooked food ranged from its limit of detection (LOD) of 5 mBq kg -1  dw (rice) to (4.0 ± 1.6) Bq kg -1  dw (marine bivalves). The concentrations of other nuclides of the 232 Th and 238 U chains in the food were low, ranging from LOD of 0.02 Bq kg -1  dw to (1.1 ± 0.3) Bq kg -1  dw. The activity concentrations of 90 Sr, 137 Cs, and 239+240 Pu in the food were minor compared to that of the natural radionuclides. The average annual committed effective dose to adults in the study region was estimated and it ranged from 0.24 to 0.42 mSv a -1 with an average of 0.32 mSv a -1 , out of which rice, leafy vegetable, and tofu contributed up to 16.2%, 24.4%, and 21.3%, respectively. The committed effective doses to adults due to ingestion of regular diet in the Red River delta region, Vietnam are within the range determined in other countries worldwide. This finding suggests that Vietnamese food is safe for human consumption with respect to radiation exposure.

  9. Dilemmas in examining understanding of nature of science in Vietnam

    Science.gov (United States)

    Thao-Do, Thi Phuong; Yuenyong, Chokchai

    2017-06-01

    Scholars proved nature of science (NOS) has made certain contributions to science teaching and learning. Nonetheless, what, how and how much NOS should be integrated in the science curriculum of each country cannot be a benchmark, due to the influence of culture and society. Before employing NOS in a new context, it should be carefully studied. In assessing views of NOS in Vietnam, a developing country with Eastern culture where the NOS is not consider a compulsory learning outcome, there are several issues that researchers and educators should notice to develop an appropriate instrument that can clearly exhibit a NOS view of Vietnamese. They may include: time for the survey; length, content, type, and terms of the questionnaire; Vietnamese epistemology and philosophy; and some other Vietnamese social and cultural aspects. The most important reason for these considerations is that a Vietnamese view of NOS and NOS assessment possibly differs from the Western ideas due to the social and cultural impact. As a result, a Western assessment tool may become less effective in an Eastern context. The suggestions and implications in this study were derived from a prolonged investigation on Vietnamese science teacher educators and student teachers of School of Education, at Can Tho University, a State University in Mekong Delta region, Vietnam.

  10. Climate adaptation and innovation in Mekong aquaculture ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Climate adaptation and innovation in Mekong aquaculture – AQUADAPT Mekong ... severe weather events and rising sea levels that impact regional hydrology. ... Research and Development Institute, Cambodia; National University of Laos; ...

  11. Utilization of downscaled microwave satellite data and GRACE Total Water Storage anomalies for improving streamflow prediction in the Lower Mekong Basin

    Science.gov (United States)

    Lakshmi, V.; Gupta, M.; Bolten, J. D.

    2016-12-01

    The Mekong river is the world's eighth largest in discharge with draining an area of 795,000 km² from the Eastern watershed of the Tibetan Plateau to the Mekong Delta including, Myanmar, Laos PDR, Thailand, Cambodia, Vietnam and three provinces of China. The populations in these countries are highly dependent on the Mekong River and they are vulnerable to the availability and quality of the water resources within the Mekong River Basin. Soil moisture is one of the most important hydrological cycle variables and is available from passive microwave satellite sensors (such as AMSR-E, SMOS and SMAP), but their spatial resolution is frequently too coarse for effective use by land managers and decision makers. The merging of satellite observations with numerical models has led to improved land surface predictions. Although performance of the models have been continuously improving, the laboratory methods for determining key hydraulic parameters are time consuming and expensive. The present study assesses a method to determine the effective soil hydraulic parameters using a downscaled microwave remote sensing soil moisture product based on the NASA Advanced Microwave Scanning Radiometer (AMSR-E). The soil moisture downscaling algorithm is based on a regression relationship between 1-km MODIS land surface temperature and 1-km Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) to produce an enhanced spatial resolution ASMR-E-based soil moisture product. Since the optimized parameters are based on the near surface soil moisture information, further constraints are applied during the numerical simulation through the assimilation of GRACE Total Water Storage (TWS) within the land surface model. This work improves the hydrological fluxes and the state variables are optimized and the optimal parameter values are then transferred for retrieving hydrological fluxes. To evaluate the performance of the system in helping improve

  12. Remote Sensing of River Delta Inundation: Exploiting the Potential of Coarse Spatial Resolution, Temporally-Dense MODIS Time Series

    Directory of Open Access Journals (Sweden)

    Claudia Kuenzer

    2015-07-01

    Full Text Available River deltas belong to the most densely settled places on earth. Although they only account for 5% of the global land surface, over 550 million people live in deltas. These preferred livelihood locations, which feature flat terrain, fertile alluvial soils, access to fluvial and marine resources, a rich wetland biodiversity and other advantages are, however, threatened by numerous internal and external processes. Socio-economic development, urbanization, climate change induced sea level rise, as well as flood pulse changes due to upstream water diversion all lead to changes in these highly dynamic systems. A thorough understanding of a river delta’s general setting and intra-annual as well as long-term dynamic is therefore crucial for an informed management of natural resources. Here, remote sensing can play a key role in analyzing and monitoring these vast areas at a global scale. The goal of this study is to demonstrate the potential of intra-annual time series analyses at dense temporal, but coarse spatial resolution for inundation characterization in five river deltas located in four different countries. Based on 250 m MODIS reflectance data we analyze inundation dynamics in four densely populated Asian river deltas—namely the Yellow River Delta (China, the Mekong Delta (Vietnam, the Irrawaddy Delta (Myanmar, and the Ganges-Brahmaputra (Bangladesh, India—as well as one very contrasting delta: the nearly uninhabited polar Mackenzie Delta Region in northwestern Canada for the complete time span of one year (2013. A complex processing chain of water surface derivation on a daily basis allows the generation of intra-annual time series, which indicate inundation duration in each of the deltas. Our analyses depict distinct inundation patterns within each of the deltas, which can be attributed to processes such as overland flooding, irrigation agriculture, aquaculture, or snowmelt and thermokarst processes. Clear differences between mid

  13. Data sharing in international transboundary contexts: The Vietnamese perspective on data sharing in the Lower Mekong Basin

    Science.gov (United States)

    Thu, Hang Ngo; Wehn, Uta

    2016-05-01

    Transboundary data sharing is widely recognised as a necessary element in the successful handling of water-related climate change issues, as it is a means towards integrated water resources management (IWRM). However, in practice it is often a challenge to achieve it. The Mekong River Commission (MRC), an inter-governmental agency established by Cambodia, Lao PDR, Thailand and Vietnam, has adopted IWRM in its water strategy plan in order to properly manage the transboundary waters of the Mekong River. In this context, data sharing procedures were institutionalised and have been officially implemented by the four member countries since 2001. This paper uses a systematic approach to identify the extent of data sharing and the factors influencing the willingness of key individuals in the Vietnam National Mekong Committee and its Primary Custodians to share data. We find that the initial objectives of the Procedures for Data and Information Exchange and Sharing (PDIES) have not been fully achieved and, further, that Vietnam has much to gain and little to lose by engaging in data sharing in the MRC context. The primary motivation for data sharing stems from the desire to protect national benefits and to prevent upstream countries from overexploiting the shared water resources. However, data sharing is hindered by a lack of national regulations in the Vietnam context concerning data sharing between state agencies and outdated information management systems.

  14. Implications of tidally-varying bed stress and intermittent estuarine stratification on fine-sediment dynamics through the Mekong's tidal river to estuarine reach

    Science.gov (United States)

    McLachlan, R. L.; Ogston, A. S.; Allison, M. A.

    2017-09-01

    River gauging stations are often located upriver of tidal propagation where sediment transport processes and storage are impacted by widely varying ratios of marine to freshwater influence. These impacts are not yet thoroughly understood. Therefore, sediment fluxes measured at these stations may not be suitable for predicting changes to coastal morphology. To characterize sediment transport dynamics in this understudied zone, flow velocity, salinity, and suspended-sediment properties (concentration, size, and settling velocity) were measured within the tidal Sông Hậu distributary of the lower Mekong River, Vietnam. Fine-sediment aggregation, settling, and trapping rates were promoted by seasonal and tidal fluctuations in near-bed shear stress as well as the intermittent presence of a salt wedge and estuary turbidity maximum. Beginning in the tidal river, fine-grained particles were aggregated in freshwater. Then, in the interface zone between the tidal river and estuary, impeded near-bed shear stress and particle flux convergence promoted settling and trapping. Finally, in the estuary, sediment retention was further encouraged by stratification and estuarine circulation which protected the bed against particle resuspension and enhanced particle aggregation. These patterns promote mud export ( 1.7 t s-1) from the entire study area in the high-discharge season when fluvial processes dominate and mud import ( 0.25 t s-1) into the estuary and interface zone in the low-discharge season when estuarine processes dominate. Within the lower region of the distributaries, morphological change in the form of channel abandonment was found to be promoted within minor distributaries by feedbacks between channel depth, vertical mixing, and aggregate trapping. In effect, this field study sheds light on the sediment trapping capabilities of the tidal river - estuary interface zone, a relatively understudied region upstream of where traditional concepts place sites of deposition

  15. Operation Sealords: A Front in a Frontless War, an Analysis of the Brown-Water Navy in Vietnam

    National Research Council Canada - National Science Library

    McQuilkin, William

    1997-01-01

    ... the flow of enemy infiltration of men and material from Cambodia into the Mekong Delta. Second, this study analyzes the Denial of Sanctuary Operations and Pacification portion of the SEALORDS operations...

  16. Trade patterns facilitating highly pathogenic avian influenza virus dissemination in the free-grazing layer duck system in Vietnam.

    Science.gov (United States)

    Meyer, A; Dinh, T X; Han, T A; Do, D V; Nhu, T V; Pham, L T; Nguyen, T T T; Newman, S; Häsler, B; Pfeiffer, D U; Vergne, T

    2018-04-01

    Highly pathogenic avian influenza (HPAI) viruses continue to threaten smallholder poultry producers in several South-east Asian countries, including Vietnam. In particular, the free-grazing duck system has been repeatedly highlighted as a major risk factor for HPAI outbreaks. Free-grazing ducks, which scavenge on rice paddies after the harvest, account for a large proportion of the duck population in Vietnam and the wider South-east Asian region. However, the structure and dynamics of the free-grazing duck production from farm to consumption has not been described for Vietnam. In this study, we used a value chain approach to provide a complete picture of the actors involved in the production and marketing of free-grazing duck eggs and spent layer ducks, as well as to investigate the governance structure of this food system. Group interviews and key informant interviews were conducted in two provinces located in the Mekong River Delta (MRD) and the Red River Delta (RRD). The results presented here highlight similarities and differences in farming and trade practices between the two provinces. The trade of spent layer ducks involved large volumes of live ducks being sent to China and Cambodia for consumption, generating a substantial risk of transboundary spread of pathogens, including HPAI viruses. We describe the major role of "duck yards", which act as hubs in the northbound trade of spent layer ducks. These yards should be considered as essential links in the value chain of spent layer ducks when considering HPAI surveillance and control. The veterinary authorities are only marginally involved in the value chain activities, and their influence could be strengthened by increasing surveillance activities for instance in duck yards. Last, we discuss the dynamics of the duck value chain and further implications for future HPAI management policies. © 2017 The Authors. Transboundary and Emerging Diseases Published by Blackwell Verlag GmbH.

  17. Detection and Characterization of Clade 1 Reassortant H5N1 Viruses Isolated from Human Cases in Vietnam during 2013.

    Directory of Open Access Journals (Sweden)

    Sharmi W Thor

    Full Text Available Highly pathogenic avian influenza (HPAI H5N1 is endemic in Vietnamese poultry and has caused sporadic human infection in Vietnam since 2003. Human infections with HPAI H5N1 are of concern due to a high mortality rate and the potential for the emergence of pandemic viruses with sustained human-to-human transmission. Viruses isolated from humans in southern Vietnam have been classified as clade 1 with a single genome constellation (VN3 since their earliest detection in 2003. This is consistent with detection of this clade/genotype in poultry viruses endemic to the Mekong River Delta and surrounding regions. Comparison of H5N1 viruses detected in humans from southern Vietnamese provinces during 2012 and 2013 revealed the emergence of a 2013 reassortant virus with clade 1.1.2 hemagglutinin (HA and neuraminidase (NA surface protein genes but internal genes derived from clade 2.3.2.1a viruses (A/Hubei/1/2010-like; VN12. Closer analysis revealed mutations in multiple genes of this novel genotype (referred to as VN49 previously associated with increased virulence in animal models and other markers of adaptation to mammalian hosts. Despite the changes identified between the 2012 and 2013 genotypes analyzed, their virulence in a ferret model was similar. Antigenically, the 2013 viruses were less cross-reactive with ferret antiserum produced to the clade 1 progenitor virus, A/Vietnam/1203/2004, but reacted with antiserum produced against a new clade 1.1.2 WHO candidate vaccine virus (A/Cambodia/W0526301/2012 with comparable hemagglutination inhibition titers as the homologous antigen. Together, these results indicate changes to both surface and internal protein genes of H5N1 viruses circulating in southern Vietnam compared to 2012 and earlier viruses.

  18. Integrated Interventions to Tackle Antimicrobial Usage in Animal Production Systems: The ViParc Project in Vietnam

    Directory of Open Access Journals (Sweden)

    Juan J. Carrique-Mas

    2017-06-01

    Full Text Available Antimicrobial usage and antimicrobial resistance (AMR in animal production is now recognized to be an important contributor to the global problem of AMR. Initiatives to curb indiscriminate antimicrobial use in animal production are currently being discussed in many low- and middle-income countries. Well-designed, scientifically sound interventions aimed to tackle excessive antimicrobial usage should provide scientists and policy makers with evidence of the highest quality to guide changes in policy and to formulate better targeted research initiatives. However, since large-scale interventions are costly, they require careful planning in order not to waste valuable resources. Here, we describe the components of the ViParc project (www.viparc.org, one of the first large-scale interventions of its kind to tackle excessive antimicrobial usage in Southeast Asian animal production systems. The project has been formulated as a “randomized before-and-after controlled study” targeting small-scale poultry farms in the Mekong Delta region of Vietnam. It aims to provide farmers with a locally-adapted veterinary support service to help them reduce their reliance on antimicrobials. ViParc has been developed in the backdrop of efforts by the Government of Vietnam to develop a National Action Plan to reduce Antimicrobials in Livestock and Aquaculture. Crucially, the project integrates socio-economic analyses that will provide insights into the drivers of antimicrobial usage, as well as an assessment of the cost-effectiveness of the proposed intervention. Information generated from ViParc should help the Government of Vietnam refine its policies to curb excessive antimicrobial usage in poultry production, while lessons from ViParc will help tackle excessive antimicrobial usage in other productions systems in Vietnam and in the broader Southeast Asian region.

  19. Integrated Interventions to Tackle Antimicrobial Usage in Animal Production Systems: The ViParc Project in Vietnam.

    Science.gov (United States)

    Carrique-Mas, Juan J; Rushton, Jonathan

    2017-01-01

    Antimicrobial usage and antimicrobial resistance (AMR) in animal production is now recognized to be an important contributor to the global problem of AMR. Initiatives to curb indiscriminate antimicrobial use in animal production are currently being discussed in many low- and middle-income countries. Well-designed, scientifically sound interventions aimed to tackle excessive antimicrobial usage should provide scientists and policy makers with evidence of the highest quality to guide changes in policy and to formulate better targeted research initiatives. However, since large-scale interventions are costly, they require careful planning in order not to waste valuable resources. Here, we describe the components of the ViParc project (www.viparc.org), one of the first large-scale interventions of its kind to tackle excessive antimicrobial usage in Southeast Asian animal production systems. The project has been formulated as a "randomized before-and-after controlled study" targeting small-scale poultry farms in the Mekong Delta region of Vietnam. It aims to provide farmers with a locally-adapted veterinary support service to help them reduce their reliance on antimicrobials. ViParc has been developed in the backdrop of efforts by the Government of Vietnam to develop a National Action Plan to reduce Antimicrobials in Livestock and Aquaculture. Crucially, the project integrates socio-economic analyses that will provide insights into the drivers of antimicrobial usage, as well as an assessment of the cost-effectiveness of the proposed intervention. Information generated from ViParc should help the Government of Vietnam refine its policies to curb excessive antimicrobial usage in poultry production, while lessons from ViParc will help tackle excessive antimicrobial usage in other productions systems in Vietnam and in the broader Southeast Asian region.

  20. Challenges and Approaches in River Delta Planning - Annexes to report on training workshop

    NARCIS (Netherlands)

    Wosten, J.H.M.; Douven, W.; Long Phi, H.; Fida Abdullah Khan, M.

    2012-01-01

    Programme, participants and all powerpoint presentations of the Delta Alliance Training Workshop: Challenges and approaches in river delta planning, sharing experiences from SE Asian Deltas and the Rhine-Meuse Delta. 22-26 October 2012, WACC, Vietnam National University, Ho Chi Minh City, Vietnam

  1. Rice-planted area extraction by time series analysis of ENVISAT ASAR WS data using a phenology-based classification approach: A case study for Red River Delta, Vietnam

    Science.gov (United States)

    Nguyen, D.; Wagner, W.; Naeimi, V.; Cao, S.

    2015-04-01

    Recent studies have shown the potential of Synthetic Aperture Radars (SAR) for mapping of rice fields and some other vegetation types. For rice field classification, conventional classification techniques have been mostly used including manual threshold-based and supervised classification approaches. The challenge of the threshold-based approach is to find acceptable thresholds to be used for each individual SAR scene. Furthermore, the influence of local incidence angle on backscatter hinders using a single threshold for the entire scene. Similarly, the supervised classification approach requires different training samples for different output classes. In case of rice crop, supervised classification using temporal data requires different training datasets to perform classification procedure which might lead to inconsistent mapping results. In this study we present an automatic method to identify rice crop areas by extracting phonological parameters after performing an empirical regression-based normalization of the backscatter to a reference incidence angle. The method is evaluated in the Red River Delta (RRD), Vietnam using the time series of ENVISAT Advanced SAR (ASAR) Wide Swath (WS) mode data. The results of rice mapping algorithm compared to the reference data indicate the Completeness (User accuracy), Correctness (Producer accuracy) and Quality (Overall accuracies) of 88.8%, 92.5 % and 83.9 % respectively. The total area of the classified rice fields corresponds to the total rice cultivation areas given by the official statistics in Vietnam (R2  0.96). The results indicates that applying a phenology-based classification approach using backscatter time series in optimal incidence angle normalization can achieve high classification accuracies. In addition, the method is not only useful for large scale early mapping of rice fields in the Red River Delta using the current and future C-band Sentinal-1A&B backscatter data but also might be applied for other rice

  2. Application Of Induced Mutation Combined With Hybridization Method In Rice Improvement In Southern Vietnam

    International Nuclear Information System (INIS)

    Do Khac Thinh; Dao Minh So; Nguyen Thi Cuc; Hung Phi Oanh; Hoang Duc Dung

    2008-01-01

    Rice plays an important role of social-economic issues in Vietnam, especially in Mekong River Delta (MRD). Rice mutation breeding was not initiated until 1992 in Southern Vietnam. Therefore, no mutant rice varieties were cultivated in MRD before 1995. Dry and germinated seeds of varieties as IR64, Tam Xoan, Nang Huong were exposed to 60 Co gamma rays at doses of 200-300 Gy. Population of 10,000-15,000 M1 plants were established by direct seeded practice. Mutant elite lines were used in hybridization program, assessed according to the standard system for rice (IRRI 1996) from M2 - M7 generations. The promising selected lines were tested in multi-location trials. The mutated characters developed so far consist of better resistance to lodging, disease and insect damages, higher tolerance to soil stresses such as acid sulphate, drought etc, and also earliness and higher yield potential. Mutation techniques have shown very useful in rice improvement, especially for characters controlled by close linked genes that are difficult to break by recombination. Some best mutant varieties: VND95-19, VND95-20, VND99-3, TNDB-100 have been released for large-scale production in MRD. Among them, VND95-20 has become one of the top 5 varieties for export and grown annually about 300,000 ha in Southern Vietnam. In combination with hybridization method, some mutants gave promising recombinants in aroma, tolerance to BPH, Grassy Stunt Virus and Ragged Stunt Virus diseases. Selected varieties as VN121, VN24-4 are largely released into production in recent time. (author)

  3. Household trends in access to improved water sources and sanitation facilities in Vietnam and associated factors: findings from the Multiple Indicator Cluster Surveys, 2000–2011

    Science.gov (United States)

    Tuyet-Hanh, Tran Thi; Lee, Jong-Koo; Oh, Juhwan; Van Minh, Hoang; Ou Lee, Chul; Hoan, Le Thi; Nam, You-Seon; Long, Tran Khanh

    2016-01-01

    Background Despite progress made by the Millennium Development Goal (MDG) number 7.C, Vietnam still faces challenges with regard to the provision of access to safe drinking water and basic sanitation. Objective This paper describes household trends in access to improved water sources and sanitation facilities separately, and analyses factors associated with access to improved water sources and sanitation facilities in combination. Design Secondary data from the Vietnam Multiple Indicator Cluster Survey in 2000, 2006, and 2011 were analyzed. Descriptive statistics and tests of significance describe trends over time in access to water and sanitation by location, demographic and socio-economic factors. Binary logistic regressions (2000, 2006, and 2011) describe associations between access to water and sanitation, and geographic, demographic, and socio-economic factors. Results There have been some outstanding developments in access to improved water sources and sanitation facilities from 2000 to 2011. In 2011, the proportion of households with access to improved water sources and sanitation facilities reached 90% and 77%, respectively, meeting the 2015 MDG targets for safe drinking water and basic sanitation set at 88% and 75%, respectively. However, despite these achievements, in 2011, only 74% of households overall had access to combined improved drinking water and sanitation facilities. There were also stark differences between regions. In 2011, only 47% of households had access to both improved water and sanitation facilities in the Mekong River Delta compared with 94% in the Red River Delta. In 2011, households in urban compared to rural areas were more than twice as likely (odds ratio [OR]: 2.2; 95% confidence interval [CI]: 1.9–2.5) to have access to improved water and sanitation facilities in combination, and households in the highest compared with the lowest wealth quintile were over 40 times more likely (OR: 42.3; 95% CI: 29.8–60.0). Conclusions More

  4. Household trends in access to improved water sources and sanitation facilities in Vietnam and associated factors: findings from the Multiple Indicator Cluster Surveys, 2000–2011

    Directory of Open Access Journals (Sweden)

    Tran Thi Tuyet-Hanh

    2016-02-01

    Full Text Available Background: Despite progress made by the Millennium Development Goal (MDG number 7.C, Vietnam still faces challenges with regard to the provision of access to safe drinking water and basic sanitation. Objective: This paper describes household trends in access to improved water sources and sanitation facilities separately, and analyses factors associated with access to improved water sources and sanitation facilities in combination. Design: Secondary data from the Vietnam Multiple Indicator Cluster Survey in 2000, 2006, and 2011 were analyzed. Descriptive statistics and tests of significance describe trends over time in access to water and sanitation by location, demographic and socio-economic factors. Binary logistic regressions (2000, 2006, and 2011 describe associations between access to water and sanitation, and geographic, demographic, and socio-economic factors. Results: There have been some outstanding developments in access to improved water sources and sanitation facilities from 2000 to 2011. In 2011, the proportion of households with access to improved water sources and sanitation facilities reached 90% and 77%, respectively, meeting the 2015 MDG targets for safe drinking water and basic sanitation set at 88% and 75%, respectively. However, despite these achievements, in 2011, only 74% of households overall had access to combined improved drinking water and sanitation facilities. There were also stark differences between regions. In 2011, only 47% of households had access to both improved water and sanitation facilities in the Mekong River Delta compared with 94% in the Red River Delta. In 2011, households in urban compared to rural areas were more than twice as likely (odds ratio [OR]: 2.2; 95% confidence interval [CI]: 1.9–2.5 to have access to improved water and sanitation facilities in combination, and households in the highest compared with the lowest wealth quintile were over 40 times more likely (OR: 42.3; 95% CI: 29.8–60

  5. Household trends in access to improved water sources and sanitation facilities in Vietnam and associated factors: findings from the Multiple Indicator Cluster Surveys, 2000-2011.

    Science.gov (United States)

    Tuyet-Hanh, Tran Thi; Lee, Jong-Koo; Oh, Juhwan; Van Minh, Hoang; Ou Lee, Chul; Hoan, Le Thi; Nam, You-Seon; Long, Tran Khanh

    2016-01-01

    Despite progress made by the Millennium Development Goal (MDG) number 7.C, Vietnam still faces challenges with regard to the provision of access to safe drinking water and basic sanitation. This paper describes household trends in access to improved water sources and sanitation facilities separately, and analyses factors associated with access to improved water sources and sanitation facilities in combination. Secondary data from the Vietnam Multiple Indicator Cluster Survey in 2000, 2006, and 2011 were analyzed. Descriptive statistics and tests of significance describe trends over time in access to water and sanitation by location, demographic and socio-economic factors. Binary logistic regressions (2000, 2006, and 2011) describe associations between access to water and sanitation, and geographic, demographic, and socio-economic factors. There have been some outstanding developments in access to improved water sources and sanitation facilities from 2000 to 2011. In 2011, the proportion of households with access to improved water sources and sanitation facilities reached 90% and 77%, respectively, meeting the 2015 MDG targets for safe drinking water and basic sanitation set at 88% and 75%, respectively. However, despite these achievements, in 2011, only 74% of households overall had access to combined improved drinking water and sanitation facilities. There were also stark differences between regions. In 2011, only 47% of households had access to both improved water and sanitation facilities in the Mekong River Delta compared with 94% in the Red River Delta. In 2011, households in urban compared to rural areas were more than twice as likely (odds ratio [OR]: 2.2; 95% confidence interval [CI]: 1.9-2.5) to have access to improved water and sanitation facilities in combination, and households in the highest compared with the lowest wealth quintile were over 40 times more likely (OR: 42.3; 95% CI: 29.8-60.0). More efforts are required to increase household access to

  6. Development of a Computerized Aid to Integrated Land Use Planning (CAILUP) at regional level in irrigated areas : a case study for the Qaun Lo Phung Hiep region in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Hoanh, C.T.

    1996-01-01

    The problem - Objectives of the study

    Land use planning is an essential activity in any country, because the demands for different land uses usually exceed the available resources. Land use planning implies weighting of

  7. Vietnam Revisited.

    Science.gov (United States)

    Esper, George

    1990-01-01

    Reflections of an Associated Press special correspondent on a return visit to Vietnam 15 years after the war. Discusses the social and economic impact of the war on Vietnam. Examines the plight of the Vietnamese who served in the U.S. military, discussing the problems of Amerasians. Recounts the efforts of U.S. veterans to rebuild Vietnam. (RW)

  8. Arsenic mobilization processes in the red river delta, Vietnam. Towards a better understanding of the patchy distribution of dissolved arsenic in alluvial deposits

    Energy Technology Data Exchange (ETDEWEB)

    Eiche, Elisabeth

    2009-07-01

    In this work the spatial variability of dissolved arsenic concentrations in aquifers was studied in a small village in the vicinity of Ha Noi, Vietnam. The main goal was to identify major geochemical, sedimentological and hydrochemical differences between high and low arsenic regions. Furthermore, the behaviour of arsenic and other elements during sequential extractions on a micrometer scale was characterized with micro synchrotron XRF analysis. Based on the results a conceptual model was developed which could explain the current situation in the village. Moreover, it could help to identify high arsenic areas throughout the world and, therefore, prevent the installation of drinking water wells in arsenic burdened regions. (orig.)

  9. Quality of Antimicrobial Products Used in Striped Catfish (Pangasianodon hypophthalmus) Aquaculture in Vietnam

    Science.gov (United States)

    Phu, Tran Minh; Phuong, Nguyen Thanh; Scippo, Marie-Louise; Dalsgaard, Anders

    2015-01-01

    Antimicrobial usage is common in Asian aquaculture. This study aimed to determine the quality of antimicrobial products used by Vietnamese striped catfish (Pangasianodon hypophthalmus) farmers. Twenty one antimicrobial products (11 products contained a single antimicrobial and 10 products contained a mixture of two different antimicrobials) commonly used by catfish farmers were obtained from so-called chemical shops located in the Mekong Delta, Vietnam. Ultra High Performance Liquid Chromatography Mass Spectrometry was used to analyze concentration of sulfonamides, trimethoprim, amoxicillin, cefalexin and ciprofloxacin whereas concentrations of florfenicol and doxycycline were analyzed by High Performance Liquid Chromatography with UV detection. Results revealed that only 4/11 products with a single antimicrobial and 2/10 products with a mixture of antimicrobials contained active substances within ±10% of the concentration declared on the product label. Two products with antimicrobial mixtures did not contain any of the declared antimicrobials. Comparing two batches, analysis of 11 products revealed that only one product contained a concentration of active compound that varied with less than 10% in both batches. Several product labels provided inadequate information on how to calculate therapeutic dosage and further stated withdrawal time despite lack of pharmacokinetic data on the antimicrobials in catfish. There is an urgent need to strengthen approval procedures and in particular regularly to monitor the quality of antimicrobials used in Vietnamese aquaculture. PMID:25897517

  10. Poverty, economic growth, deprivation, and water: the cases of Cambodia and Vietnam.

    Science.gov (United States)

    Varis, Olli

    2008-05-01

    Poverty reduction decorates all development agendas, but the complexity of the poverty issue is too often hidden behind simplistic indicators and development goals. Here, a closer look is taken at the concepts of "deprivation" and "vulnerability" as outcomes of poverty. Deprivation leads typically to social exclusion and marginalization; such groups are particularly weak in getting themselves out of poverty by "self-help," and economic growth does not trickle down to these people. When looking at the connections between poverty reduction and economic growth, special emphasis should be put on the differences between modern and more traditional sectors: development of the modern sector should not marginalize and exclude those dependent on more traditional livelihoods. Two case studies--The Tonle Sap area, Cambodia, and the Mekong Delta, Vietnam--reveal that investment in education, empowerment of small-scale entrepreneurship and other means of microeconomic environment, along with good governance, infrastructure, and income distribution can ensure that economic growth includes the poorer echelons of society.

  11. Quality of Antimicrobial Products Used in Striped Catfish (Pangasianodon hypophthalmus Aquaculture in Vietnam.

    Directory of Open Access Journals (Sweden)

    Tran Minh Phu

    Full Text Available Antimicrobial usage is common in Asian aquaculture. This study aimed to determine the quality of antimicrobial products used by Vietnamese striped catfish (Pangasianodon hypophthalmus farmers. Twenty one antimicrobial products (11 products contained a single antimicrobial and 10 products contained a mixture of two different antimicrobials commonly used by catfish farmers were obtained from so-called chemical shops located in the Mekong Delta, Vietnam. Ultra High Performance Liquid Chromatography Mass Spectrometry was used to analyze concentration of sulfonamides, trimethoprim, amoxicillin, cefalexin and ciprofloxacin whereas concentrations of florfenicol and doxycycline were analyzed by High Performance Liquid Chromatography with UV detection. Results revealed that only 4/11 products with a single antimicrobial and 2/10 products with a mixture of antimicrobials contained active substances within ±10% of the concentration declared on the product label. Two products with antimicrobial mixtures did not contain any of the declared antimicrobials. Comparing two batches, analysis of 11 products revealed that only one product contained a concentration of active compound that varied with less than 10% in both batches. Several product labels provided inadequate information on how to calculate therapeutic dosage and further stated withdrawal time despite lack of pharmacokinetic data on the antimicrobials in catfish. There is an urgent need to strengthen approval procedures and in particular regularly to monitor the quality of antimicrobials used in Vietnamese aquaculture.

  12. The transmission of Fasciola spp. to cattle and contamination of grazing areas with Fasciola eggs in the Red River Delta region of Vietnam.

    Science.gov (United States)

    Lan Anh, Nguyen Thi; Thanh, Dao Thi Ha; Hoan, Doan Huu; Thuy, Do Thu; Khong, Nguyen Viet; Anderson, Norman

    2014-04-01

    At four times during November 2010, cattle with infections of Fasciola spp., in two communes of northern Vietnam, were allocated to two equivalent groups. Cattle in one group were treated with triclabendazole. Faecal samples collected monthly from both groups were tested for Fasciola copro-antigens and the presence of Fasciola eggs. Re-infection of treated cattle occurred from early March to late November, coinciding with high weekly totals of rainfall. Contamination of grazing areas by untreated cattle was high and relatively constant throughout the year. However, contamination was reduced to undetectable amounts for 8 to 12 weeks after treatment and even at 20 weeks was only 50% or less of the pre-treatment amounts. Therefore, treatments given in mid-September and again in early April, at the start of the wet season, may be sufficient to prevent contamination of grazing areas and reduce the prevalence and severity of Fasciola infections in cattle.

  13. Spatio-Temporal Occurrence Modeling of Highly Pathogenic Avian Influenza Subtype H5N1: A Case Study in the Red River Delta, Vietnam

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    Chinh C. Tran

    2013-11-01

    Full Text Available Highly Pathogenic Avian Influenza (HPAI subtype H5N1 poses severe threats to both animals and humans. Investigating where, when and why the disease occurs is important to help animal health authorities develop effective control policies. This study takes into account spatial and temporal occurrence of HPAI H5N1 in the Red River Delta of Vietnam. A two-stage procedure was used: (1 logistic regression modeling to identify and quantify factors influencing the occurrence of HPAI H5N1; and (2 a geostatistical approach to develop monthly predictive maps. The results demonstrated that higher average monthly temperatures and poultry density in combination with lower average monthly precipitation, humidity in low elevation areas, roughly from November to January and April to June, contribute to the higher occurrence of HPAI H5N1. Provinces near the Gulf of Tonkin, including Hai Phong, Hai Duong, Thai Binh, Nam Dinh and Ninh Binh are areas with higher probability of occurrence of HPAI H5N1.

  14. Prevalence of waterpipe tobacco smoking among population aged 15 years or older, Vietnam, 2010.

    Science.gov (United States)

    Xuan, Le Thi Thanh; Van Minh, Hoang; Giang, Kim Bao; Nga, Pham Thi Quynh; Hai, Phan Thi; Minh, Nguyen Thac; Hsia, Jason

    2013-04-18

    The prevalence of waterpipe tobacco smoking is increasing globally and is associated with adverse outcomes requiring tobacco control interventions. We estimated the prevalence of waterpipe tobacco use among adult populations in Vietnam in 2010 and examined its association with sociodemographic factors. We used data from the Global Adult Tobacco Survey (GATS) conducted in Vietnam in 2010. GATS surveyed a national representative sample of adults aged 15 years or older from 11,142 households by using a 2-phase sampling design analogous to a 3-stage stratified cluster sampling. Descriptive statistical analyses and multivariate logistic regression modeling were conducted. A total of 6.4% of Vietnamese aged 15 years or older (representing about 4.1 million adult waterpipe smokers) reported current waterpipe tobacco smoking. The prevalence of waterpipe tobacco smoking was significantly higher among men than women (13% vs 0.1%). Area of residence (rural or urban), age group, asset-based wealth quintile, and geographic region of residence were significantly associated with waterpipe tobacco smoking among men. The significant correlates of current waterpipe tobacco smoking among men were lower education levels, being middle-aged (45-54 years), lower asset-based wealth levels, living in rural areas, not living in the South East and the Mekong River Delta geographic regions, and the belief that smoking does not causes diseases. Rural dwellers who are poor should be targeted in tobacco control programs. Further studies are needed that examine perceptions of the adverse health effects and the cultural factors of waterpipe tobacco smoking.

  15. Impact of value chain governance on the development of small scale shrimp farmers in Vietnam

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    T. M. H. Ho

    2016-06-01

    Full Text Available Purpose of this paper is to identify the tendency of shrimp value chain development and impact of its governance on the small scale shrimp farmers in Vietnam. Design/methodology/approach - Data from the shrimp farmers surveys in Mekong delta, Vietnam from 2008-2010 with the update information in 2014 were taken to analyse by the value chain analysis method. Findings – Traditional governance type of the shrimp value chain in the early state (before 2004 showed the different levels of coordination of farmers with collectors, among collectors, and collectors with processing plants. In this type of governance, trust and linkages are inextricably linked. However, they are not strong. The processing plants determine shrimp prices and quality requirement in the market while many collectors do not seem to be highly responsible for the quality of their products. To avoid this limitation, with the governmental support policy to improve farmers’ income, the processing plants set up a direct buying from farmers under contracts. These contracts led to a new governance type with an expectation of improving farmers' position. However, this model was broken due to several reasons including un-controlled shrimp raw material from small scale and individual farmers. Consequently, processors now tend to establish their own raw material zone to comply shrimp quality assurance, and eject the existence of farmers. This will lead small scale farmers to very difficult problems in finding the market. Poverty and social problems of small scale farmers might appear. The result recommends a greater strengthening and tightening of the value chain. Re-organizing shrimp farmers into legal teams or groups that help farmers to re-participate in the game with others actor in the chain is crucial. Research limitations/implications - The research mainly follows inductive approach in w

  16. Assessment of climate change impact on river flow regimes in The Red River Delta, Vietnam – A case study of the Nhue-Day River Basin

    Directory of Open Access Journals (Sweden)

    Phan Cao Duong

    2016-09-01

    Full Text Available Global warming has caused dramatic changes in regional climate variability, particularly regarding fluctuations in temperature and rainfall. Thus, it is predicted that river flow regimes will be altered accordingly. The purpose of this paper is to present the results of modeling such changes by simulating discharge using the HEC-HMS model. The precipitation was projected using super-high resolution multiple climate models (20 km resolution with newly updated emission scenarios as the input for the HEC-HMS model for flow analysis at the Red River Basin in the northern area of Vietnam. The findings showed that climate change impact on the river flow regimes tend towards a decrease in the dry season and a longer duration of flood flow. A slight runoff reduction is simulated for November while a considerable runoff increase is modeled for July and August amounting to 30% and 25%, respectively. The discharge scenarios serve as a basis for water managers to develop suitable adaptation methods and responses on the river basin scale.

  17. GC51D-0831: A Study of the Impact of Dams on Sediment Retention in the Mekong River Basin

    Science.gov (United States)

    Munroe, Thailynn; Griffin, Robert; Anderson, Eric; Markert, Kel

    2017-01-01

    Dam construction in the Mekong Basin has many cascading effects on the ecology, economy, and hydrology of the surrounding region. The focus of this study is to utilize the Soil Water Assessment Tool (SWAT), developed at Texas A & M, a rainfall-runoff hydrologic model to determine change in sedimentation in the Mekong Basin after the construction of dams. This study uses land cover land use and reservoir datasets created by the NASA SERVIR-Mekong Regional Land Cover Monitoring System and Dam Inundation Mapping Tool as inputs into the model. The study also builds on the capabilities of the SWAT model by using the sediment trapping efficiency (STE) equation from Brune (1953), rewritten by Kummu & Varis (2007), to calculate STE of dams and estimate change in sediment concentration downstream. The outputs from this study can be used to inform dam operation policies, study the correlation between dams and delta subsidence, and study the impact of dams on river fisheries, which are all pressing issues in the Mekong region.

  18. A Study of the Impact of Dams on Streamflow and Sediment Retention in the Mekong River Basin

    Science.gov (United States)

    Munroe, T.; Anderson, E.; Markert, K. N.; Griffin, R.

    2017-12-01

    Dam construction in the Mekong Basin has many cascading effects on the ecology, economy, and hydrology of the surrounding region. Current studies that assess the hydrological impact of dams in the region focus on only one or a small subset (SWAT), a rainfall-runoff hydrologic model to determine change in streamflow and sedimentation in the Mekong Basin before and after the construction of dams. This study uses land cover land use and reservoir datasets created by the NASA SERVIR-Mekong Regional Land Cover Monitoring System and Dam Inundation Mapping Tool as inputs into the model. The study also builds on the capabilities of the SWAT model by using the sediment trapping efficiency (STE) equation from Brune (1953), rewritten by Kummu (2007), to calculate STE of dams and estimate change in sediment concentration downstream. The outputs from this study can be used to inform dam operation policies, study the correlation between dams and delta subsidence, and study the impact of dams on river fisheries, which are all pressing issues in the Mekong region.

  19. Tonle Sap Lake Water Storage Change Over 24 Years From Satellite Observation and Its Link With Mekong River Discharge and Climate Events

    Science.gov (United States)

    Biancamaria, S.; Frappart, F.; Normandin, C.; Blarel, F.; Bourrel, L.; Aumont, M.; Azema, P.; Vu, P. L.; Lubac, B.; Darrozes, J.

    2017-12-01

    The Tonle Sap lake is the largest freshwater lake in Southeast Asia and is located within the Mekong basin (mainly in Cambodia). It is one of he most productive ecosystem of the world and provide two thirds of Cambodia fish catch. It also plays a unique role on the Mekong basin hydrological cycle: during the monsoon period, the Mekong river partially flows to the lake, whereas during the dry season, the lake flows to the Mekong delta. It is therefore crucial to monitor and take into account this lake to estimate Mekong discharge to the ocean. However, in situ measurements of lake level and river discharge are very sparse (especially during the last decades) and computing lake storage variation from in situ data only is difficult due to the huge annual variation of lake area. That's why, satellite data (nadir radar altimetry and visible imagery) have been used to study its volume variation and its relationship with climate events and Mekong river discharge. Multi-mission altimetry data have been extracted (Topex, ERS-2, ENVISAT, Jason-1, Jason-2, Saral and Jason-3, using CTOH data extraction tools) to derive a lake water level from1993 to 2016, which varies from 3 m to 12 m. Lake area have been computed from MODIS data from 2000 to 2016 and varies from 3,400 km2 to 11,800 km2. These dataset clearly shows a relationship between lake water level and area, which has been used to estimate lake water volume change from 1995 to 2016, with a minimum in 2015 and a maximum in 2011. Lake's droughts and floods can be observed during moderate and strong El Nino/La Nina events, enhanced by the Pacific Decadal Oscillation. Besides, comparison with in situ discharge at the outlet of the Mekong basin (over 1995/2000 time period) shows that lake water level is 20 days time lagged and increases/decreases after Mekong discharge at its outlet. This time lag results of Mekong river partially flowing to the lake. Finally, high correlation between lake level and outlet discharge allows to

  20. The Mekong Fish Network: expanding the capacity of the people and institutions of the Mekong River Basin to share information and conduct standardized fisheries monitoring

    Science.gov (United States)

    Patricio, Harmony C.; Ainsley, Shaara M.; Andersen, Matthew E.; Beeman, John W.; Hewitt, David A.

    2012-01-01

    The Mekong River is one of the most biologically diverse rivers in the world, and it supports the most productive freshwater fisheries in the world. Millions of people in the Lower Mekong River Basin (LMB) countries of the Union of Myanmar (Burma), Lao People’s Democratic Republic, the Kingdom of Thailand, the Kingdom of Cambodia, and the Socialist Republic of Vietnam rely on the fisheries of the basin to provide a source of protein. The Mekong Fish Network Workshop was convened in Phnom Penh, Cambodia, in February 2012 to discuss the potential for coordinating fisheries monitoring among nations and the utility of establishing standard methods for short- and long-term monitoring and data sharing throughout the LMB. The concept for this network developed out of a frequently cited need for fisheries researchers in the LMB to share their knowledge with other scientists and decisionmakers. A fish monitoring network could be a valuable forum for researchers to exchange ideas, store data, or access general information regarding fisheries studies in the LMB region. At the workshop, representatives from governments, nongovernmental organizations, and universities, as well as participating foreign technical experts, cited a great need for more international cooperation and technical support among them. Given the limited staff and resources of many institutions in the LMB, the success of the proposed network would depend on whether it could offer tools that would provide benefits to network participants. A potential tool discussed at the workshop was a user-friendly, Web-accessible portal and database that could help streamline data entry and storage at the institutional level, as well as facilitate communication and data sharing among institutions. The workshop provided a consensus to establish pilot standardized data collection and database efforts that will be further reviewed by the workshop participants. Overall, workshop participants agreed that this is the type of

  1. Induction of Antimicrobial Resistance in Escherichia coli and Non-Typhoidal Salmonella Strains after Adaptation to Disinfectant Commonly Used on Farms in Vietnam

    Directory of Open Access Journals (Sweden)

    Nguyen T. Nhung

    2015-10-01

    Full Text Available In Vietnam, commercial disinfectants containing quaternary ammonium compounds (QACs are commonly used in pig and poultry farms to maintain hygiene during production. We hypothesized that sustained exposure to sub-bactericidal concentrations of QAC-based disinfectants may result in increased levels of antimicrobial resistance (AMR among Enterobacteriacea due to the increase of efflux pump expression. To test this hypothesis we exposed six antimicrobial-susceptible Escherichia coli (E. coli and six antimicrobial-susceptible non-typhoidal Salmonella (NTS isolates to increasing concentrations of a commonly used commercial disinfectant containing a mix of benzalkonium chloride and glutaraldehyde. Over the 12-day experiment, strains exhibited a significant change in their minimum inhibitory concentration (MIC of the disinfectant product (mean increase of 31% (SD ± 40 (p = 0.02, paired Wilcoxon test. Increases in MIC for the disinfectant product were strongly correlated with increases in MIC (or decreases in inhibition zone for all antimicrobials (Pearson’s correlation coefficient 0.71–0.83, all p < 0.01. The greatest increases in MIC (or decreases in inhibition zone were observed for ampicillin, tetracycline, ciprofloxacin, and chloramphenicol, and the smallest for gentamicin, trimethoprim/sulphamethoxazole. The treatment of 155 representative E. coli isolates from farmed and wild animals in the Mekong Delta (Vietnam with phenyl-arginine beta-naphthylamide (PAβN, a generic efflux pump inhibitor, resulted in reductions in the prevalence of AMR ranging from 0.7% to 3.3% in these organisms, indicating a small contribution of efflux pumps on the observed prevalence of AMR on farms. These results suggest that the mass usage of commercial disinfectants, many of which contain QACs, is potentially a contributing factor on the generation and maintenance of AMR in animal production in Vietnam.

  2. Malaria in the Greater Mekong Subregion: Heterogeneity and Complexity

    Science.gov (United States)

    Cui, Liwang; Yan, Guiyun; Sattabongkot, Jetsumon; Cao, Yaming; Chen, Bin; Chen, Xiaoguang; Fan, Qi; Fang, Qiang; Jongwutiwes, Somchai; Parker, Daniel; Sirichaisinthop, Jeeraphat; Kyaw, Myat Phone; Su, Xin-zhuan; Yang, Henglin; Yang, Zhaoqing; Wang, Baomin; Xu, Jianwei; Zheng, Bin; Zhong, Daibin; Zhou, Guofa

    2011-01-01

    The Greater Mekong Subregion (GMS), comprised of six countries including Cambodia, China's Yunnan Province, Lao PDR, Myanmar (Burma), Thailand and Vietnam, is one of the most threatening foci of malaria. Since the initiation of the WHO's Mekong Malaria Program a decade ago, malaria situation in the GMS has greatly improved, reflected in the continuous decline in annual malaria incidence and deaths. However, as many nations are moving towards malaria elimination, the GMS nations still face great challenges. Malaria epidemiology in this region exhibits enormous geographical heterogeneity with Myanmar and Cambodia remaining high-burden countries. Within each country, malaria distribution is also patchy, exemplified by ‘border malaria’ and ‘forest malaria’ with high transmission occurring along international borders and in forests or forest fringes, respectively. ‘Border malaria’ is extremely difficult to monitor, and frequent malaria introductions by migratory human populations constitute a major threat to neighboring, malaria-eliminating countries. Therefore, coordination between neighboring countries is essential for malaria elimination from the entire region. In addition to these operational difficulties, malaria control in the GMS also encounters several technological challenges. Contemporary malaria control measures rely heavily on effective chemotherapy and insecticide control of vector mosquitoes. However, the spread of multidrug resistance and potential emergence of artemisinin resistance in Plasmodium falciparum make resistance management a high priority in the GMS. This situation is further worsened by the circulation of counterfeit and substandard artemisinin-related drugs. In most endemic areas of the GMS, P. falciparum and P. vivax coexist, and in recent malaria control history, P. vivax has demonstrated remarkable resilience to control measures. Deployment of the only registered drug (primaquine) for the radical cure of vivax malaria is

  3. Assessment of plastic waste generation and its potential recycling of household solid waste in Can Tho City, Vietnam.

    Science.gov (United States)

    Thanh, Nguyen Phuc; Matsui, Yasuhiro; Fujiwara, Takeshi

    2011-04-01

    Plastic solid waste has become a serious problem when considering the disposal alternatives following the sequential hierarchy of sound solid waste management. This study was undertaken to assess the quantity and composition of household solid waste, especially plastic waste to identify opportunities for waste recycling. A 1-month survey of 130 households was carried out in Can Tho City, the capital city of the Mekong Delta region in southern Vietnam. Household solid waste was collected from each household and classified into ten physical categories; especially plastic waste was sorted into 22 subcategories. The average household solid waste generation rate was 281.27 g/cap/day. The compostable and recyclable shares respectively accounted for high percentage as 80.74% and 11%. Regarding plastic waste, the average plastic waste generation rate was 17.24 g/cap/day; plastic packaging and plastic containers dominated with the high percentage, 95.64% of plastic waste. Plastic shopping bags were especially identified as the major component, accounting for 45.72% of total plastic waste. Relevant factors such as household income and household size were found to have an existing correlation to plastic waste generation in detailed composition. The household habits and behaviors of plastic waste discharge and the aspects of environmental impacts and resource consumption for plastic waste disposal alternatives were also evaluated.

  4. The 'Brazilian Test' as an indicator of workability for paddy soils in Vietnam

    NARCIS (Netherlands)

    Hoogmoed, W.B.; Nguyen, V.L.

    2006-01-01

    Farmers in Mekong delta prefer to till their soil in dry conditions when possible. They claim that crops establish and yield better when the field have been ploughed when dry compared to the wet preparation by puddling. Experiments were carried out to investigate the optimum workabilty range for the

  5. Estimating the burden of Japanese encephalitis virus and other encephalitides in countries of the mekong region.

    Directory of Open Access Journals (Sweden)

    Arnaud Tarantola

    Full Text Available Diverse aetiologies of viral and bacterial encephalitis are widely recognized as significant yet neglected public health issues in the Mekong region. A robust analysis of the corresponding health burden is lacking. We retrieved 75 articles on encephalitis in the region published in English or in French from 1965 through 2011. Review of available data demonstrated that they are sparse and often derived from hospital-based studies with significant recruitment bias. Almost half (35 of 75 of articles were on Japanese encephalitis virus (JEV alone or associated with dengue. In the Western Pacific region the WHO reported 30,000-50,000 annual JEV cases (15,000 deaths between 1966 and 1996 and 4,633 cases (200 deaths in 2008, a decline likely related to the introduction of JEV vaccination in China, Vietnam, or Thailand since the 1980s. Data on dengue, scrub typhus and rabies encephalitis, among other aetiologies, are also reviewed and discussed. Countries of the Mekong region are undergoing profound demographic, economic and ecological change. As the epidemiological aspects of Japanese encephalitis (JE are transformed by vaccination in some countries, highly integrated expert collaborative research and objective data are needed to identify and prioritize the human health, animal health and economic burden due to JE and other pathogens associated with encephalitides.

  6. Tide-Dominated Tract (TDT) as a key sedimentary zone characterizing tide-dominated large-river delta and estuary systems

    Science.gov (United States)

    Saito, Y.

    2017-12-01

    Large rivers in continents have a characteristic of slow rise and fall in water levels during floods or the wet season due to a wide drainage basin. A gentle river gradient and large water discharge have relatively large tidal ranges at the river mouth, resulting in large backwater effects further upstream. The result of the Mekong River survey (386 riverbed sediments, river topography, CTD, and biofacies) shows that the distributary channels of the Mekong River delta in Vietnam are divided into two parts: the landward river-dominated tract (RDT) and seaward tide-dominated tract (TDT). The RDT is characterized by a highly variable and deepening trend in water depth and coarse-grained sediments with a fining trend downstream. The TDT is characterized by a shallowing trend in water depth with river-widening, smooth riverbeds, a straight shape, and heterolithic f- to vf-sand and mud alternation (tidal thythmite). The boundary of both tracts is sharply identified by sediment facies and river morphology. Sediment facies indicates that the dominant sedimentary process of bottom sediments is "bedload" in the RDT and "suspension" in the TDT. Daily tidal changes are observed through the year, while water-level changes during the flood/wet season are limited in the TDT. Saltwater intrusion is limited within the seaward part of the TDT alone ( 50 km), close to final bifurcation points. However, brackish-water biofacies is observed in the TDT mainly due to diluted brackish water and/or tolerance to the freshwater environment. These characteristics are also found in the Yangtze; the distance of the TDT/RDT boundary from the river mouth is ca. 100 km in the Mekong, and 200 km in the Yangtze. The preservation potential of sediments in a TDT is low in a progradational system, and high in abandoned channels. The early Holocene transgressive estuary system in the incised valley of the Yangtze formed during the Last Glacial Maximum was composed of 20 m-thick fine-grained heterolithic

  7. Building Exposure Maps Of Urban Infrastructure And Crop Fields In The Mekong River Basin

    Science.gov (United States)

    Haas, E.; Weichselbaum, J.; Gangkofner, U.; Miltzer, J.; Wali, A.

    2013-12-01

    In the frame of the Integrated Water Resources Management (IWRM) initiative for the Mekong river basin World Bank is collaborating with the Mekong River Commission and governmental organizations in Cambodia, Lao PDR, Thailand and Vietnam to build national and regional capacities for managing the risks associated with natural disasters, such as floods, flash floods and droughts. Within ‘eoworld', a joint initiative set up by ESA and World Bank to foster the use of Earth Observation (EO) for sustainable development work, a comprehensive database of elements at risk in the Lower Mekong river basin has been established by GeoVille, including urban infrastructure and crops (primarily rice paddies). In the long term, this exposure information shall be fed into an open-source multi- hazard modeling tool for risk assessment along the Mekong River, which then shall be used by national stakeholders as well as insurance and financial institutions for planning, disaster preparedness and emergency management. Earth Observation techniques can provide objective, synoptic and repetitive observations of elements at risk including buildings, infrastructure and crops. Through the fusion of satellite-based with in-situ data from field surveys and local knowledge (e.g. on building materials) features at risk can be characterised and mapped with high accuracy. Earth Observation data utilised comprise bi-weekly Envisat ASAR imagery programmed for a period of 9 months in 2011 to map the development of the rice cultivation area, identify predominant cropping systems (wet-season vs. dry season cultivation), crop cycles (single /double / triple crop per year), date of emergence/harvest and the distinction between rice planted under intensive (SRI) vs. regular rice cultivation techniques. Very High Resolution (VHR) optical data from SPOT, KOMPSAT and QuickBird were used for mapping of buildings and infrastructure, such as building footprints, residential / commercial areas, industrial

  8. Report on technological achievements in fiscal 1999. Survey on geological structures in overseas countries, 'Japan-Vietnam joint coal exploration project on Red River delta'; 1999 nendo kaigai chishitsu kozo nado chosa hokokusho. Nippon Vietnam sekitan kyodo tansa Red River delta project

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-06-01

    With an objective to identify stratigraphy, geological structures, coal bed existing status, and coal quality of major coal beds in the north and central district of the area to be surveyed in the Red River delta, test well drilling, physical and seismic exploration, and coal composition analyses were performed. The area to be surveys is a typical delta where irrigation canals are running in all directions. Three test wells were drilled with drilling lengths of 640 m for TD3, 700 m for TD4 and 900 m for TD5. Coring was performed to depths greater than the Tertiary deposit. The seismic exploration was executed along three exploration lines. Total distance was 25 km. In addition, the VSP investigation was carried out on TD3 and TD5. The stratigraphy is composed from below of the Phu Cu bed (Neogene period: marine deposit) , the Tien Hung bed (Neogene period: continental deposit), and the Tai Doung bed (quaternary deposit), in which the bed that holds coal beds is the Tien Hung bed. The beds are very stable as the geological structure, but the constituting rocks are soft and fragile. Anticipated coal beds exist in depths greater than 1000 m. The coal quality is of low ash, low sulfur, medium in calorific power, and contains little gas. (NEDO)

  9. Planning the development of the Mekong river basin

    Energy Technology Data Exchange (ETDEWEB)

    Chomchai, P [Mekong Secretariat, Bangkok (Thailand)

    1992-10-01

    In planning to develop the vast potential of the Mekong river in Southeast Asia, a number of institutional aspects need to be addressed, and the sometimes diverging interests of the riparian countries need to be carefully balanced. The Mekong river is an extremely valuable natural resource: its potential for irrigation, hydropower, navigation, fisheries and related development is more than adequate to raise significantly the standards of living of the people of the lower Mekong basin and in the riparian countries outside the river's catchment area. The Mekong's catchment area of 795 000 km[sup 2] encompasses parts of China and Myanmar, the whole of Laos and Cambodia, one third of Thailand and one fifth of Viet Nam. The population of the Mekong basin is around 100 million, about half of whom live in the lower basin. It could be said that these impoverished inhabitants of the basin depend significantly on the Mekong for an improvement in their livelihood, and this places a heavy responsibility on those involved in developing its water resources. The Mekong Committee, since its establishment in 1957 and in its present interim status since 1977, is dedicated to the co-ordinated development of the basin's resources, on the basis of reasonable and equitable sharing between the riparian states as stated in the Committee's declaration of principles. With the establishment of the Mekon Committee, serious efforts have been made aimed at rational management of water resources use. (author).

  10. Bayesian modeling approach for characterizing groundwater arsenic contamination in the Mekong River basin.

    Science.gov (United States)

    Cha, YoonKyung; Kim, Young Mo; Choi, Jae-Woo; Sthiannopkao, Suthipong; Cho, Kyung Hwa

    2016-01-01

    In the Mekong River basin, groundwater from tube-wells is a major drinking water source. However, arsenic (As) contamination in groundwater resources has become a critical issue in the watershed. In this study, As species such as total As (AsTOT), As(III), and As(V), were monitored across the watershed to investigate their characteristics and inter-relationships with water quality parameters, including pH and redox potential (Eh). The data illustrated a dramatic change in the relationship between AsTOT and Eh over a specific Eh range, suggesting the importance of Eh in predicting AsTOT. Thus, a Bayesian change-point model was developed to predict AsTOT concentrations based on Eh and pH, to determine changes in the AsTOT-Eh relationship. The model captured the Eh change-point (∼-100±15mV), which was compatible with the data. Importantly, the inclusion of this change-point in the model resulted in improved model fit and prediction accuracy; AsTOT concentrations were strongly negatively related to Eh values higher than the change-point. The process underlying this relationship was subsequently posited to be the reductive dissolution of mineral oxides and As release. Overall, AsTOT showed a weak positive relationship with Eh at a lower range, similar to those commonly observed in the Mekong River basin delta. It is expected that these results would serve as a guide for establishing public health strategies in the Mekong River Basin. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. DELTAS: A new Global Delta Sustainability Initiative (Invited)

    Science.gov (United States)

    Foufoula-Georgiou, E.

    2013-12-01

    , Vietnam, and Canada. Key components of the DELTAS Sustainability Initiative are: integrated research on deltas as coupled socio-ecological systems undergoing change (Delta-SRES), a global delta data depository (Delta-DAT), a suite of open access delta risk assessment and decision support modeling tools (Delta-RADS), and the coordinated demonstration of these activities in deltas around the world (Delta-ACT).

  12. Catalyzing action towards the sustainability of deltas: deltas as integrated socio-ecological systems and sentinels of regional and global change

    Science.gov (United States)

    Foufoula-Georgiou, E.; Tessler, Z. D.; Brondizio, E.; Overeem, I.; Renaud, F.; Sebesvari, Z.; Nicholls, R. J.; Anthony, E.

    2016-12-01

    Deltas are highly dynamic and productive environments: they are food baskets of the world, home to biodiverse and rich ecosystems, and they play a central role in food and water security. However, they are becoming increasingly vulnerable to risks arising from human activities, land subsidence, regional water management, global sea-level rise, and climate extremes. Our Belmont Forum DELTAS project (BF-DELTAS: Catalyzing actions towards delta sustainability) encompasses an international network of interdisciplinary research collaborators with focal areas in the Mekong, Ganges Brahmaputra, and the Amazon deltas. The project is organized around five main modules: (1) developing an analytical framework for assessing delta vulnerability and scenarios of change (Delta-SRES), (2) developing an open-acess, science-based integrative modeling framework for risk assessment and decision support (Delta-RADS), (3) developing tools to support quantitative mapping of the bio-physical and socio-economic environments of deltas and consolidate bio-physical and social data within shared data repositories (Delta-DAT), (4) developing Global Delta Vulnerability Indices (Delta-GDVI) that capture current and projected scenarios for major deltas around the world , and (5) collaborating with regional stakeholders to put the science, modeling, and data into action (Delta-ACT). In this talk, a research summary will be presented on three research domains around which significant collaborative work was developed: advancing biophysical classification of deltas, understanding deltas as coupled socio-ecological systems, and analyzing and informing social and environmental vulnerabilities in delta regions.

  13. Private equity, public affair: Hydropower financing in the Mekong Basin

    NARCIS (Netherlands)

    Merme, V.; Ahlers, R.; Gupta, J.

    2014-01-01

    Large-scale hydropower development is increasingly popular. Although international finance is a significant driver of hydropower market expansion, financial data is relatively obscure and literature remains scarce. This article tracks the financial process in hydropower development in the Mekong

  14. Tides Stabilize Deltas until Humans Interfere

    Science.gov (United States)

    Hoitink, T.; Zheng Bing, W.; Vermeulen, B.; Huismans, Y.; Kastner, K.

    2017-12-01

    Despite global concerns about river delta degradation caused by extraction of natural resources, sediment retention by reservoirs and sea-level rise, human activity in the world's largest deltas intensifies. In this review, we argue that tides tend to stabilize deltas until humans interfere. Under natural circumstances, delta channels subject to tides are more stable than their fluvial-dominated counterparts. The oscillatory tidal flow counteracts the processes responsible for bank erosion, which explains why unprotected tidal channels migrate only slowly. Peak river discharges attenuate the tides, which creates storage space to accommodate the extra river discharge during extreme events and as a consequence, reduce flood risk. With stronger tides, the river discharge is being distributed more evenly over the various branches in a delta, preventing silting up of smaller channels. Human interference in deltas is massive. Storm surge barriers are constructed, new land is being reclaimed and large-scale sand excavation takes place, to collect building material. Evidence from deltas around the globe shows that in human-controlled deltas the tidal motion often plays a destabilizing role. In channels of the Rhine-Meuse Delta, some 100 scour holes are identified, which relates to the altered tidal motion after completion of a storm surge barrier. Sand mining has led to widespread river bank failures in the tidally-influenced Mekong Delta. The catastrophic flood event in the Gauges-Brahmaputra Delta by Cyclone Aila, which caused the inundation of an embanked polder area for over two years, was preceded by river bank erosion at the mouths of formal tidal channels that were blocked by the embankment. Efforts to predict the developments of degrading deltas are few. Existing delta models are capable of reproducing expanding deltas, which is essentially a matter of simulating the transport of sediment from source in a catchment to the sink in a delta. Processes of soil

  15. Characterization of future drought conditions in the Lower Mekong River Basin

    Directory of Open Access Journals (Sweden)

    Madusanka Thilakarathne

    2017-09-01

    Full Text Available This study evaluates future changes to drought characteristics in the Lower Mekong River Basin using climate model projections. The Lower Mekong Basin (LMB, covering Thailand, Cambodia, Laos and Vietnam, is vulnerable to increasing droughts. Univariate analysis was employed in this study to compare drought characteristics associated with different return periods for the historical period 1964–2005 and future scenarios (RCP 4.5 2016–2057, RCP 4.5 2058–2099, RCP 8.5 2016–2057 and RCP 8.5 2058–2099. Because a single drought event is defined by several correlated characteristics, drought risk assessment by a multivariate analysis was deemed appropriate, and a multivariate analysis of droughts was conducted using copula functions to investigate the differences in the trivariate joint occurrence probabilities of the historical period and future scenarios. The Standardized Precipitation Index (SPI was selected as the drought index because of its ability to detect and compare metrological droughts across time and space scales. Historical precipitation data from 1964 to 2005 and future precipitation projections from 2016 to 2099 for 15 global circulation models (GCMs obtained from the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP dataset were employed. In all future scenarios, the Lower LMB and 3S subbasins were expected to experience more severe and intense droughts. The multivariate drought risk assessment revealed an increase in drought risks in the LMB. However, the Chi-Mun subbasin may experience an alleviation of future drought characteristics. Because the basin was expected to experience an increase in average monthly precipitation in most months, the variability in magnitude suggested that the LMB region requires adaptation strategies to address future drought occurrences.

  16. RCP8.5-Based Future Flood Hazard Analysis for the Lower Mekong River Basin

    Directory of Open Access Journals (Sweden)

    Edangodage Duminda Pradeep Perera

    2017-11-01

    Full Text Available Climatic variations caused by the excessive emission of greenhouse gases are likely to change the patterns of precipitation, runoff processes, and water storage of river basins. Various studies have been conducted based on precipitation outputs of the global scale climatic models under different emission scenarios. However, there is a limitation in regional- and local-scale hydrological analysis on extreme floods with the combined application of high-resolution atmospheric general circulation models’ (AGCM outputs and physically-based hydrological models (PBHM. This study has taken an effort to overcome that limitation in hydrological analysis. The present and future precipitation, river runoff, and inundation distributions for the Lower Mekong Basin (LMB were analyzed to understand hydrological changes in the LMB under the RCP8.5 scenario. The downstream area beyond the Kratie gauging station, located in the Cambodia and Vietnam flood plains was considered as the LMB in this study. The bias-corrected precipitation outputs of the Japan Meteorological Research Institute atmospheric general circulation model (MRI-AGCM3.2S with 20 km horizontal resolution were utilized as the precipitation inputs for basin-scale hydrological simulations. The present climate (1979–2003 was represented by the AMIP-type simulations while the future (2075–2099 climatic conditions were obtained based on the RCP8.5 greenhouse gas scenario. The entire hydrological system of the Mekong basin was modelled by the block-wise TOPMODEL (BTOP hydrological model with 20 km resolution, while the LMB area was modelled by the rainfall-runoff-inundation (RRI model with 2 km resolution, specifically to analyze floods under the aforementioned climatic conditions. The comparison of present and future river runoffs, inundation distributions and inundation volume changes were the outcomes of the study, which can be supportive information for the LMB flood management, water policy

  17. Spatio-temporal patterns of soil erosion and suspended sediment dynamics in the Mekong River Basin.

    Science.gov (United States)

    Suif, Zuliziana; Fleifle, Amr; Yoshimura, Chihiro; Saavedra, Oliver

    2016-10-15

    Understanding of the distribution patterns of sediment erosion, concentration and transport in river basins is critically important as sediment plays a major role in river basin hydrophysical and ecological processes. In this study, we proposed an integrated framework for the assessment of sediment dynamics, including soil erosion (SE), suspended sediment load (SSL) and suspended sediment concentration (SSC), and applied this framework to the Mekong River Basin. The Revised Universal Soil Loss Equation (RUSLE) model was adopted with a geographic information system to assess SE and was coupled with a sediment accumulation and a routing scheme to simulate SSL. This framework also analyzed Landsat imagery captured between 1987 and 2000 together with ground observations to interpolate spatio-temporal patterns of SSC. The simulated SSL results from 1987 to 2000 showed the relative root mean square error of 41% and coefficient of determination (R(2)) of 0.89. The polynomial relationship of the near infrared exoatmospheric reflectance and the band 4 wavelength (760-900nm) to the observed SSC at 9 sites demonstrated the good agreement (overall relative RMSE=5.2%, R(2)=0.87). The result found that the severe SE occurs in the upper (China and Lao PDR) and lower (western part of Vietnam) regions. The SSC in the rainy season (June-November) showed increasing and decreasing trends longitudinally in the upper (China and Lao PDR) and lower regions (Cambodia), respectively, while the longitudinal profile of SSL showed a fluctuating trend along the river in the early rainy season. Overall, the results described the unique spatio-temporal patterns of SE, SSL and SSC in the Mekong River Basin. Thus, the proposed integrated framework is useful for elucidating complex process of sediment generation and transport in the land and river systems of large river basins. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Land cover, land use, and climate change impacts on agriculture in southern Vietnam

    Science.gov (United States)

    Kontgis, Caitlin

    Global environmental change is rapidly changing the surface of the Earth in varied and irrevocable ways. Across the world, land cover and land use have been altered to accommodate the needs of expanding populations, and climate change has required plant, animal, and human communities to adapt to novel climates. These changes have created unprecedented new ecosystems that affect the planet in ways that are not fully understood and difficult to predict. Of utmost concern is food security, and whether agro-ecosystems will adapt and respond to widespread changes so that growing global populations can be sustained. To understand how one staple food crop, rice, responds to global environmental change in southern Vietnam, this dissertation aims to accomplish three main tasks: (1) quantify the rate and form of urban and peri-urban expansion onto cropland using satellite imagery and demographic data, (2) track changes to annual rice paddy harvests using time series satellite data, and (3) model the potential effects of climate change on rice paddies by incorporating farmer interview data into a crop systems model. The results of these analyses show that the footprint of Ho Chi Minh City grew nearly five times between 1990 and 2012. Mismatches between urban development and population growth suggest that peri-urbanization is driven by supply-side investment, and that much of this form of land expansion has occurred near major transit routes. In the nearby Mekong River Delta, triple-cropped rice paddy area doubled between 2000 and 2010, from one-third to two-thirds of rice fields, while paddy area expanded by about 10%. These results illustrate the intensification of farming practices since Vietnam liberalized its economy, yet it is not clear whether such practices are environmentally sustainable long-term. Although triple-cropped paddy fields have expanded, future overall production is estimated to decline without the effects of CO2 fertilization. Temperatures are anticipated

  19. Assessing landscape hydroperiods across the Mekong Basin using multi-scale remote sensing to understand water-energy-food tradeoffs

    Science.gov (United States)

    Torbick, N.; Salas, W.; Qi, J.; Huang, X.

    2017-12-01

    In the Lower Mekong River Basin (LMRB), population growth and transitioning economies, shifting climate, and intense pressures for resources are driving tradeoffs among the water-enegery-food (WEF) nexus. Rice production and irrigation, wetlands habitat, and damn constructions are intertwinned across the region. There are 11 major hydropower dams on the main stem of the Lower Mekong River and many smaller dams in the basin. At the same time increased pressure for food production has amplified cropping intensity and irrigation infrastructure projects. These human acitivies are impacting inundation patterns and phenology of wetland and lake ecosystems. We are mapping rice, wetlands, and lake inundation dynamics using multi-scale satellite remote sensing. New opportunities exist for moderate scale, near-daily mapping of rice, wetland, shrimp, and lake hydroperiod with multi-source imaging and BigData computational approaches on the NAS cloud. Primarily we rely on Sentinel-1 IW and PALSAR-2 ScanSAR to map inundation dynamics at 10m resolution including under canopy conditions using double bounce properties. As part of this effort we are assessing different damn impacts at case studies in Thailand, Cambodia, Laos, and Vietnam with high resolution commercial imagery, social surveys, and socioeconomic models. These dams are currently regulated individually without coordination. As a result, their operation has outsized impacts on lake and wetland ecologies, negatively affecting the associated ecosystem services that local communities have relied on. All new products are shared openly with the science community. Case study illustrations will be presented.

  20. Vietnam: Historians at War

    Science.gov (United States)

    Moyar, Mark

    2008-01-01

    Although the Vietnam War ended more than thirty years ago, historians remain as divided on what happened as the American people were during the war. Mark Moyar maps the ongoing battle between "orthodox" and "revisionist" Vietnam War historians: the first group, those who depict Vietnam as a bad war that the United States should…

  1. Conceptualizing responsible innovation in craft villages in Vietnam

    NARCIS (Netherlands)

    Voeten, J.; de Haan, J.A.C.; Roome, N.; de Groot, G.A.; Nguyen Thi, Huong; van den Hoven, J.; Doorn, N.; Swierstra, T.; Koops, B.-J.; Romijn, H.

    2014-01-01

    Previous research by the authors has explored small-scale innovations in poor craft producers’ clusters in villages in the Red River Delta in northern Vietnam. Although these innovations resulted in value creation and increased incomes, they also often gave rise to negative environmental or social

  2. Climate politics in the Lower Mekong Basin. National interests and transboundary cooperation on climate change

    Energy Technology Data Exchange (ETDEWEB)

    Baadsgaard Lange, R.; Moerck Jensen, K.

    2013-09-01

    Climate change is expected to intensify water security concerns in international river basins. UNFCCC and DAC-donors have been important generators of political attention to the climate agenda among governments in the Mekong Basin in relation to regional cooperation, national policy-making and capacity building. However, the formal commitment to climate action is not necessarily reflected in the everyday business of development. In this paper we use a political economy approach to understand when and how climate change becomes a political priority for the governments of Laos, Thailand and Vietnam, and for transboundary cooperation. Uneven distribution of climate hazards and vulnerabilities create different national risk perceptions and commitment to climate action. Donor funding and national development strategies are also strong drivers of climate action and inaction. Climate change is sometimes used as a scapegoat for domestic policy failures and as a tool to acquire donor funding. We recommend prioritizing climate action in the context of immediate development challenges and 'no regrets' interventions that are likely to enhance adaptive capacity and governments' commitment. (Author)

  3. The acceptability, efficacy and safety of quinacrine non-surgical sterilization (QS), tubectomy and vasectomy in 5 provinces in the Red River Delta, Vietnam: a follow-up of 15,190 cases.

    Science.gov (United States)

    Hieu, D T; Luong, T T; Anh, P T; Ngoc, D H; Duong, L Q

    2003-10-01

    To compare the safety, efficacy and acceptability of quinacrine sterilization (QS), tubectomy and vasectomy in Vietnam. This study was initiated in January 1998 and completed in February 2000. A sample of 9 districts in 5 provinces, where the prevalence of QS was known to be high, was selected. Every person sterilized in these 9 districts between January 1, 1988 and March 31, 1998 was identified and systematically interviewed by family planning clinicians who had received special training for this project. A total of 15,982 sterilization users were identified and 15,190 were interviewed and examined, including a gynecologic exam, if needed: a follow-up rate of 95%. Of those interviewed, 9,753 used tubectomy, 3,734 used QS and 1,703 used vasectomy. All three methods were found to be safe, although morbidity associated with tubectomy was more serious than with QS or vasectomy. No deaths were reported. After more than 5 years of follow-up, tubectomy had the lowest failure rate: 1.0%, followed by 4.1% with vasectomy. A pregnancy rate of 13.2% was reported with quinacrine, although only a small fraction of these failures were confirmed. A strong preference for QS was found. QS has an important role to play in sterilization services in Vietnam.

  4. [Increase of entomological indices during the pre-epidemic period of dengue in Ben Tre, South Vietnam].

    Science.gov (United States)

    Nguyen, T P Q; Luu, L L; Vu, T Q H; Buisson, Y

    2011-10-01

    Dengue has emerged in Vietnam 50 years ago and since has become endemo-epidemic throughout the whole country. Each year, major epidemics of dengue fever (DF) and dengue hemorrhagic fever (DHF) hit South Vietnam during the rainy season, causing significant morbidity and mortality, especially among young children. The only preventive measure is vector control, but it is often implemented too late or indiscriminately. The aim of this study was to investigate, in the pre-epidemic stage, the existence of significant changes in vector indices, which will predict DF/DHF outbreaks. We conducted a descriptive transversal study, repeated once a month for four months (March to June) in the village of Locthuan (province Ben Tre) in the Mekong's delta. Adult mosquitoes were caught in 30 houses, and larvae were collected in water holding containers of 50 houses. The houses were randomly selected. Vector densities were calculated according to the indices recommended by WHO. Virological analysis was carried out on lots of female Aedes and larvae in order to determine viral infection rates. Catches of adult mosquitoes collected 496 specimens including 329 Aedes, 139 Culex and 28 Anopheles. Aedes aegypti was present in 63% of visited homes that is an average density of 1.8 mosquitoes per house. The increase in imaginal indices during the 4 months was not significant. The survey of breeding sites of Ae. aegypti identified 1292 water containers in which 71,569 larval specimens were collected. The values of house index, container index [CI] and Breteau index [BI] increased each month, the latter from 166 to 442. This increase was significant for CI and BI. Breeding sites were mostly intra-home, mainly consisting of large and small ceramic jars. Larval density of Ae. aegypti in the containers also increased significantly over the 4 months. It was correlated with the lack of cover and predators such as Mesocyclops spp., Micronecta spp. and larvivorous fishes. Cultivation of 15 pools of

  5. Possible Source Populations of the White-backed Planthopper in the Greater Mekong Subregion Revealed by Mitochondrial DNA Analysis

    Science.gov (United States)

    Li, Xiang-Yong; Chu, Dong; Yin, Yan-Qiong; Zhao, Xue-Qing; Chen, Ai-Dong; Khay, Sathya; Douangboupha, Bounneuang; Kyaw, Mu Mu; Kongchuensin, Manita; Ngo, Vien Vinh; Nguyen, Chung Huy

    2016-12-01

    The white-backed planthopper, Sogatella furcifera (Horváth) (Hemiptera: Delphacidae), is a serious pest of rice in Asia. However, little is known regarding the migration of this pest insect from the Greater Mekong Subregion (GMS) including Cambodia, Laos, Myanmar (Burma), Thailand, and Vietnam, into China’s Yunnan Province. To determine the migration patterns of S. furcifera in the GMS and putative secondary immigration inside China’s Yunnan Province, we investigated the population genetic diversity, genetic structure, and gene flow of 42 S. furcifera populations across the six countries in the GMS by intensive sampling using mitochondrial genes. Our study revealed the potential emigration of S. furcifera from the GMS consists primarily of three major sources: 1) the S. furcifera from Laos and Vietnam migrate into south and southeast Yunnan, where they proceed to further migrate into northeast and central Yunnan; 2) the S. furcifera from Myanmar migrate into west Yunnan, and/or central Yunnan, and/or northeast Yunnan; 3) the S. furcifera from Cambodia migrate into southwest Yunnan, where the populations can migrate further into central Yunnan. The new data will not only be helpful in predicting population dynamics of the planthopper, but will also aid in regional control programs for this economically important pest insect.

  6. Delta Dynamics

    DEFF Research Database (Denmark)

    Bendixen, Mette

    . The warming air temperature affects the soil temperature and permafrost thaws and destabilizes the material in the coastal zone. In Greenland, the warming temperature lowers the surface mass balance of the Greenland Ice Sheet and more material is transported to the coastal zone. The sea ice extent is thinning...... of a fjord and the second type is a wider fan-shaped open delta. Most deltas are directly coupled to the Greenland Ice Sheet or local icecaps and are highly influenced by the dynamics in the catchments. It is demonstrated how a modern changing climate directly affects delta dynamics, and that Greenlandic...... deltas are prograding, contrary to the global trend showing eroding Arctic coasts. Moreover, it is revealed that the increasing proglacial freshwater runoff, caused by a lowering of the surface mass balance of the Greenland Ice Sheet is the main determining agent in delta progradation. The final part...

  7. Contextualising fisheries policy in the Lower Mekong Basin

    NARCIS (Netherlands)

    Bush, S.R.

    2008-01-01

    Development policies for fishery resources within the Mekong River Basin are increasingly divided between aquaculture and capture fisheries. The modern production orientation of aquaculture has been adopted by government and NGOs and justified by the rhetoric of poverty alleviation and rural

  8. Application of thermoluminescence dating on pressed crystalline samples to determine the geological age at some areas in Eastern South, Vietnam

    International Nuclear Information System (INIS)

    Do Duy Khiem; Luu Anh Tuyen; Phan Trong Phuc; Nguyen Thi Ngoc Hue; Pham Thi Hue; La Ly Nguyen; Ha Quang Hai

    2016-01-01

    The terrestrial part of eastern margin of the Mekong Basin is formed by outcrop of the pre-Holocen Cenozoic sequence. Almost previous studies concerned in using relative methods in geologic dating at the Mekong Basin, therefore, the ages of its stratigraphy are still unclear. The thermoluminescence (TL) dating was considered as one of the precise methods in geologic dating. In our study, we used TL dating for some areas at Eastern South, Vietnam including Ba Mieu Formation and the Thu Duc Formation at some areas in Dong Nai province and Ho Chi Minh City. This work has been the first application of TL for in geologic dating by a domestic laboratory. Experimental measurements of TL were performed using pressed crystalline quartz specimens from sediment samples. The results show that the Ba Mieu Formation was deposited about 238±22 ka and the Thu Duc Formation was deposited about 199±21 ka. (author)

  9. Maternal mortality in Vietnam in 1994-95.

    Science.gov (United States)

    Hieu, D T; Hanenberg, R; Vach, T H; Vinh, D Q; Sokal, D

    1999-12-01

    This report presents the first population-based estimates of maternal mortality in Vietnam. All the deaths of women aged 15-49 in 1994-95 in three provinces of Vietnam were identified and classified by cause. Maternal mortality was the fifth most frequent cause of death. The maternal mortality ratio was 155 deaths per 100,000 live births. This ratio compares with the World Health Organization's estimates of 430 such deaths globally and 390 for Asia. The maternal mortality ratio in the delta regions of these provinces was half that of the mountainous and semimountainous regions. Because a larger proportion of the Vietnamese population live in delta regions than elsewhere, the maternal mortality ratio for Vietnam as a whole may be lower than that of the three provinces studied. Maternal mortality is low in Vietnam primarily because a relatively high proportion of deliveries take place in clinics and hospitals, where few women die in childbirth. Also, few women die of the consequences of induced abortion in Vietnam because the procedure is legal and easily available.

  10. Doing Business in Vietnam

    DEFF Research Database (Denmark)

    Meyer, Klaus E.; Tran, Thi Thu Yen; Nguyen, Hung Vo

    2005-01-01

    still reflects inheritances from the central plan system, Vietnam today has a vibrant economy with small businesses springing up at every street corner. Foreign investors have been flogging to Vietnam since the early 1990s, with a new peak of FDI inflow in 2004. This paper reviews the Vietnamese economy...

  11. Spatio-temporal variability of acid sulphate soils in the plain of reeds, Vietnam : impact of soil properties, water management and crop husbandry on the growth and yield of rice in relation to microtopography

    NARCIS (Netherlands)

    Husson, O.

    1998-01-01

    Acid sulphate soils in the Mekong delta cover 1.6 million hectares, of which 400 000 ha are located in the Plain of Reeds. Due to the presence of pyrite that yields acid when oxidised, all acid sulphate soils are (potentially) strongly acidic. Reclamation of the 150 000 ha of severely acid

  12. Contamination by arsenic and other trace elements of tube-well water along the Mekong River in Lao PDR

    International Nuclear Information System (INIS)

    Chanpiwat, Penradee; Sthiannopkao, Suthipong; Cho, Kyung Hwa; Kim, Kyoung-Woong; San, Vibol; Suvanthong, Boukeo; Vongthavady, Chantha

    2011-01-01

    Arsenic and other trace element concentrations were determined for tube-well water collected in the Lao PDR provinces of Attapeu, Bolikhamxai, Champasak, Savannakhet, Saravane, and Vientiane. Water samples, especially from floodplain areas of central and southern Laos, were significantly contaminated not only with As, but with B, Ba, Mn, U, and Fe as well. Total As concentrations ranged from -1 to 278 μg L -1 , with over half exceeding the WHO guideline of 10 μg L -1 . 46% of samples, notably, were dominated by As(III). Samples from Vientiane, further north, were all acceptable except on pH, which was below drinking water limits. A principal component analysis found associations between general water characteristics, As, and other trace elements. Causes of elevated As concentrations in Lao tube wells were considered similar to those in other Mekong River countries, particularly Cambodia and Vietnam, where young alluvial aquifers give rise to reducing conditions. - Research highlights: → Tube-well waters were significantly contaminated with As, B, Ba, Mn, U and Fe. → As contaminated areas were mostly floodplains in the central and southern parts of Laos. → As (III) was a predominant species in 46% of tube-well water samples. → A positive association between water characteristics, B and Sr contents was found. → Total As, As (III) and Fe concentrations were positively associated among each other. - In the first international research on As and other trace element contamination of tube-well water in Lao PDR, concentrations of As, B, Ba, Mn, U, and Fe exceeding drinking water guidelines were found in samples taken mostly from Mekong River floodplain areas.

  13. Contamination by arsenic and other trace elements of tube-well water along the Mekong River in Lao PDR

    Energy Technology Data Exchange (ETDEWEB)

    Chanpiwat, Penradee [School of Environmental Science and Engineering, Gwangju Institute of Science and Techonology (GIST), 261 Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju 500-712 (Korea, Republic of); Sthiannopkao, Suthipong, E-mail: suthi@gist.ac.k [International Environmental Research Center (IERC), Gwangju Institute of Science and Technology (GIST), 261 Cheomdan-gwagiro - Oryong-dong, Buk-gu, Gwangju 500-712 (Korea, Republic of); Cho, Kyung Hwa [School of Environmental Science and Engineering, Gwangju Institute of Science and Techonology (GIST), 261 Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju 500-712 (Korea, Republic of); Kim, Kyoung-Woong, E-mail: kwkim@gist.ac.k [School of Environmental Science and Engineering, Gwangju Institute of Science and Techonology (GIST), 261 Cheomdan-gwagiro (Oryong-dong), Buk-gu, Gwangju 500-712 (Korea, Republic of); San, Vibol [Department of Environmental Science, Royal University of Phnom Penh (Cambodia); Suvanthong, Boukeo; Vongthavady, Chantha [Environmental Health Division, Center for Environmental Health and Water Supply, Ministry of Health, NongBone Road, Vientiane (Lao People' s Democratic Republic)

    2011-02-15

    Arsenic and other trace element concentrations were determined for tube-well water collected in the Lao PDR provinces of Attapeu, Bolikhamxai, Champasak, Savannakhet, Saravane, and Vientiane. Water samples, especially from floodplain areas of central and southern Laos, were significantly contaminated not only with As, but with B, Ba, Mn, U, and Fe as well. Total As concentrations ranged from <0.5 {mu}g L{sup -1} to 278 {mu}g L{sup -1}, with over half exceeding the WHO guideline of 10 {mu}g L{sup -1}. 46% of samples, notably, were dominated by As(III). Samples from Vientiane, further north, were all acceptable except on pH, which was below drinking water limits. A principal component analysis found associations between general water characteristics, As, and other trace elements. Causes of elevated As concentrations in Lao tube wells were considered similar to those in other Mekong River countries, particularly Cambodia and Vietnam, where young alluvial aquifers give rise to reducing conditions. - Research highlights: Tube-well waters were significantly contaminated with As, B, Ba, Mn, U and Fe. As contaminated areas were mostly floodplains in the central and southern parts of Laos. As (III) was a predominant species in 46% of tube-well water samples. A positive association between water characteristics, B and Sr contents was found. Total As, As (III) and Fe concentrations were positively associated among each other. - In the first international research on As and other trace element contamination of tube-well water in Lao PDR, concentrations of As, B, Ba, Mn, U, and Fe exceeding drinking water guidelines were found in samples taken mostly from Mekong River floodplain areas.

  14. Mekong Land Cover Dasboard: Regional Land Cover Mointoring Systems

    Science.gov (United States)

    Saah, D. S.; Towashiraporn, P.; Aekakkararungroj, A.; Phongsapan, K.; Triepke, J.; Maus, P.; Tenneson, K.; Cutter, P. G.; Ganz, D.; Anderson, E.

    2016-12-01

    SERVIR-Mekong, a USAID-NASA partnership, helps decision makers in the Lower Mekong Region utilize GIS and Remote Sensing information to inform climate related activities. In 2015, SERVIR-Mekong conducted a geospatial needs assessment for the Lower Mekong countries which included individual country consultations. The team found that many countries were dependent on land cover and land use maps for land resource planning, quantifying ecosystem services, including resilience to climate change, biodiversity conservation, and other critical social issues. Many of the Lower Mekong countries have developed national scale land cover maps derived in part from remote sensing products and geospatial technologies. However, updates are infrequent and classification systems do not always meet the needs of key user groups. In addition, data products stop at political boundaries and are often not accessible making the data unusable across country boundaries and with resource management partners. Many of these countries rely on global land cover products to fill the gaps of their national efforts, compromising consistency between data and policies. These gaps in national efforts can be filled by a flexible regional land cover monitoring system that is co-developed by regional partners with the specific intention of meeting national transboundary needs, for example including consistent forest definitions in transboundary watersheds. Based on these facts, key regional stakeholders identified a need for a land cover monitoring system that will produce frequent, high quality land cover maps using a consistent regional classification scheme that is compatible with national country needs. SERVIR-Mekong is currently developing a solution that leverages recent developments in remote sensing science and technology, such as Google Earth Engine (GEE), and working together with production partners to develop a system that will use a common set of input data sources to generate high

  15. Modeling transport and deposition of the Mekong River sediment

    Science.gov (United States)

    Xue, Zuo; He, Ruoying; Liu, J. Paul; Warner, John C.

    2012-01-01

    A Coupled Wave–Ocean–SedimentTransport Model was used to hindcast coastal circulation and fine sedimenttransport on the Mekong shelf in southeastern Asian in 2005. Comparisons with limited observations showed that the model simulation captured the regional patterns and temporal variability of surface wave, sea level, and suspended sediment concentration reasonably well. Significant seasonality in sedimenttransport was revealed. In summer, a large amount of fluvial sediments was delivered and deposited near the MekongRiver mouth. In the following winter, strong ocean mixing, and coastal current lead to resuspension and southwestward dispersal of a small fraction of previously deposited sediments. Model sensitivity experiments (with reduced physics) were performed to investigate the impact of tides, waves, and remotely forced ambient currents on the transport and dispersal of the fluvial sediment. Strong wave mixing and downwelling-favorable coastal current associated with the more energetic northeast monsoon in the winter season are the main factors controlling the southwestward along-shelf transport.

  16. High-temperature ethanol production using thermotolerant yeast newly isolated from Greater Mekong Subregion

    Directory of Open Access Journals (Sweden)

    Atiya Techaparin

    Full Text Available Abstract The application of high-potential thermotolerant yeasts is a key factor for successful ethanol production at high temperatures. Two hundred and thirty-four yeast isolates from Greater Mekong Subregion (GMS countries, i.e., Thailand, The Lao People's Democratic Republic (Lao PDR and Vietnam were obtained. Five thermotolerant yeasts, designated Saccharomyces cerevisiae KKU-VN8, KKU-VN20, and KKU-VN27, Pichia kudriavzevii KKU-TH33 and P. kudriavzevii KKU-TH43, demonstrated high temperature and ethanol tolerance levels up to 45 °C and 13% (v/v, respectively. All five strains produced higher ethanol concentrations and exhibited greater productivities and yields than the industrial strain S. cerevisiae TISTR5606 during high-temperature fermentation at 40 °C and 43 °C. S. cerevisiae KKU-VN8 demonstrated the best performance for ethanol production from glucose at 37 °C with an ethanol concentration of 72.69 g/L, a productivity of 1.59 g/L/h and a theoretical ethanol yield of 86.27%. The optimal conditions for ethanol production of S. cerevisiae KKU-VN8 from sweet sorghum juice (SSJ at 40 °C were achieved using the Box-Behnken experimental design (BBD. The maximal ethanol concentration obtained during fermentation was 89.32 g/L, with a productivity of 2.48 g/L/h and a theoretical ethanol yield of 96.32%. Thus, the newly isolated thermotolerant S. cerevisiae KKU-VN8 exhibits a great potential for commercial-scale ethanol production in the future.

  17. Collaborative GIS for flood susceptibility mapping: An example from Mekong river basin of Viet Nam

    Science.gov (United States)

    Thanh, B.

    2016-12-01

    Flooding is one of the most dangerous natural disasters in Vietnam. Floods have caused serious damages to people and made adverse impact on social economic development across the country, especially in lower river basin where there is high risk of flooding as consequences of the climate change and social activities. This paper presents a collaborative platform of a combination of an interactive web-GIS framework and a multi-criteria evaluation (MCE) tool. MCE is carried out in server side through web interface, in which parameters used for evaluation are groups into three major categories, including (1) climatic factor: precipitation, typhoon frequency, temperature, humidity (2) physiographic data: DEM, topographic wetness index, NDVI, stream power index, soil texture, distance to river (3) social factor: NDBI, land use pattern. Web-based GIS is based on open-source technology that includes an information page, a page for MCE tool that users can interactively alter parameters in flood susceptible mapping, and a discussion page. The system is designed for local participation in prediction of the flood risk magnitude under impacts of natural processes and human intervention. The proposed flood susceptibility assessment prototype was implemented in the Mekong river basin, Viet Nam. Index images were calculated using Landsat data, and other were collected from authorized agencies. This study shows the potential to combine web-GIS and spatial analysis tool to flood hazard risk assessment. The combination can be a supportive solution that potentially assists the interaction between stakeholders in information exchange and in disaster management, thus provides for better analysis, control and decision-making.

  18. Vietnam Report No. 2415

    National Research Council Canada - National Science Library

    1982-01-01

    .... This report contains articles about Vietnam. Some topics include military affairs and public security, international relations, party activities and government, economic planning, trade and finance, agriculture, heavy industry and construction...

  19. Vietnam Report No. 2382

    National Research Council Canada - National Science Library

    1982-01-01

    .... This document contains articles on Vietnam. Some topics discussed are military affairs and public security, international relations, trade, aid, economic planning, trade and finance, agriculture, heavy industry, construction, transportation...

  20. Census in North Vietnam

    National Research Council Canada - National Science Library

    1960-01-01

    This population census decree aims at collecting the most fundamental and accurate data on the population situation of North Vietnam to lay the foundation for all plans and public administration policies...

  1. Physics in Vietnam

    International Nuclear Information System (INIS)

    Altarelli, Monica Pepe

    1994-01-01

    Vietnam is a country in rapid evolution, opening up communications with the rest of world and encouraging foreign investors. Although there is more ground to make up, the heady mixture of communism and free market they are aiming for is along the same lines as China. Jean Tran Thanh Van , who left Vietnam about forty years ago, judged that it was the right time to bring together Western and Vietnamese physicists. He promoted and organized the ''Rencontres du Vietnam'' on high energy physics and cosmology, which from December 13-18 brought together about one hundred physicists, half from Vietnam and half from abroad, in Hanoi for an intense programme to review the status of particle physics and its deep implications for cosmology

  2. Physics in Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Altarelli, Monica Pepe

    1994-03-15

    Vietnam is a country in rapid evolution, opening up communications with the rest of world and encouraging foreign investors. Although there is more ground to make up, the heady mixture of communism and free market they are aiming for is along the same lines as China. Jean Tran Thanh Van , who left Vietnam about forty years ago, judged that it was the right time to bring together Western and Vietnamese physicists. He promoted and organized the ''Rencontres du Vietnam'' on high energy physics and cosmology, which from December 13-18 brought together about one hundred physicists, half from Vietnam and half from abroad, in Hanoi for an intense programme to review the status of particle physics and its deep implications for cosmology.

  3. Vietnam Report 2014

    International Development Research Centre (IDRC) Digital Library (Canada)

    Vudddn

    entrepreneurship and business development, we believe that GEM Vietnam .... indicators have the highest levels: the dynamics of the domestic market ...... either by selling, shutting down or otherwise discontinuing an owner/management.

  4. Diabetes in Vietnam.

    Science.gov (United States)

    Khue, Nguyen Thy

    2015-01-01

    The prevalence for diabetes, prediabetes, and gestational diabetes in Vietnam are low relative to other parts of the world, but they are increasing at alarming rates. These changes have occurred in the setting of economic and cultural transitions. The aim of this study was to provide relevant information depicting the diabetes burden in Vietnam. Literature was reviewed using PubMed and local Vietnamese sources, including papers published in the Vietnamese language. In 2012, the prevalence of diabetes was 5.4% and prediabetes 13.7%. In 2005, the prevalence of obesity was 1.7%. There is a dual burden of over- and undernutrition observed in Vietnam. Diabetes is associated with an increased waist-to-hip ratio despite normal body mass index. Nutritional transitions occurred with increased protein, fat, and fast foods, and with decreased fresh fruits and vegetables. Tobacco use is very high in Vietnam with 66% of adult men currently smoking. Challenges include endocrinology training, health care coverage, patient education, and lack of coordination among government and specialist agencies. Diabetes is a growing problem in Vietnam and is associated with obesity, changes in dietary patterns, and other cultural transitions. More research is needed to better understand this health care problem and to devise targeted interventions. Copyright © 2015 The Author. Published by Elsevier Inc. All rights reserved.

  5. Trails of river monsters: Detecting critically endangered Mekong giant catfish Pangasianodon gigas using environmental DNA

    Directory of Open Access Journals (Sweden)

    Bellemain Eva

    2016-07-01

    Full Text Available Pressures on freshwater biodiversity in Southeast Asia are accelerating, yet the status and conservation needs of many of the region’s iconic fish species are poorly known. The Mekong is highly species diverse and supports four of the six largest freshwater fish globally, three of which, including Mekong giant catfish (Pangasianodon gigas, are Critically Endangered. Emerging environmental DNA (eDNA techniques have potential for monitoring threatened freshwater biodiversity, yet have not been applied in complex and biodiverse tropical ecosystems such as the Mekong. We developed species-specific primers for amplifying Mekong giant catfish DNA. In situ validation demonstrated that the DNA amplification was successful for all samples taken in reservoirs with known presence of Mekong giant catfish independent of fish density. We collected water samples from six deep pools on the Mekong, identified through Local Ecological Knowledge, in Cambodia, Lao PDR, and Thailand. DNA was extracted and amplified from these samples using the designed primers and probes. Mekong giant catfish DNA was detected from one sample from the species’ presumed spawning grounds on the Mekong mainstream, near the border between northern Thailand and Lao PDR. eDNA sampling using species-specific primers has potential for surveying and monitoring poorly known species from complex tropical aquatic environments. However accounting for false absences is likely to be required for the method to function with precision when applied to extremely rare species that are highly dispersed within a large river system. We recommend that such approach be utilised more widely by freshwater conservation practitioners for specific applications. The method is best suited for baseline biodiversity assessments or to identify and prioritise locations for more rigorous sampling. Our methods are particularly relevant for systems or species with limited baseline data or with physical characteristics

  6. Dam-Induced Sediment Starvation in Deltas: Implications for the Mekong

    Science.gov (United States)

    Kondolf, G. M.; Rubin, Z.; Minear, J. T.

    2014-12-01

    As the climate warms, especially rapid responses are being seen in the Arctic. Melting ice and thawing soils have wide ranging impacts including changes to ecosystems. What that means depends, in no small measure, on your understanding of—and relationship—to the ecosystems as evidenced by the currencies in which you measure ecosystem change. Thus, an ecologist will tend to focus on the impacts on energy flow and organizational complexity; conservationists on ecosystem services and biodiversity; and subsistence hunters on food security and cultural identity. Policy makers (a poorly defined group) will attempt to integrate all of the above within the very real limits of their fluency with each currency. The situation is further complicated by unavoidable ambiguities; abiotic and biotic influences can be difficult to distinguish, scale impacts ecosystem response unevenly, and ecosystems are useful concepts but not amenable to precise boundaries. As the risks of climate change become more evident, the cost of ambiguities and disparate currencies increases. It is imperative that scientists, conservationists, subsistence hunters, and policy makers appreciate and overcome their different ways of understanding environmental change.

  7. Transformations of Vietnamese shrimp aquaculture policy: empirical evidence from the Mekong Delta

    NARCIS (Netherlands)

    Tran Thi Thu Ha, Ha; Bush, S.R.

    2010-01-01

    International environmental and social concerns about tropical shrimp production have led to the emergence of private transnational governance and regulation. Using cases from Ca Mau we investigate how the shift to private transnational regulatory networks has changed the role of the government from

  8. Regional Assessment of Groundwater Recharge in the Lower Mekong Basin

    Directory of Open Access Journals (Sweden)

    Guillaume Lacombe

    2017-12-01

    Full Text Available Groundwater recharge remains almost totally unknown across the Mekong River Basin, hindering the evaluation of groundwater potential for irrigation. A regional regression model was developed to map groundwater recharge across the Lower Mekong Basin where agricultural water demand is increasing, especially during the dry season. The model was calibrated with baseflow computed with the local-minimum flow separation method applied to streamflow recorded in 65 unregulated sub-catchments since 1951. Our results, in agreement with previous local studies, indicate that spatial variations in groundwater recharge are predominantly controlled by the climate (rainfall and evapotranspiration while aquifer characteristics seem to play a secondary role at this regional scale. While this analysis suggests large scope for expanding agricultural groundwater use, the map derived from this study provides a simple way to assess the limits of groundwater-fed irrigation development. Further data measurements to capture local variations in hydrogeology will be required to refine the evaluation of recharge rates to support practical implementations.

  9. Fluvial sediment supply to a mega-delta reduced by shifting tropical-cyclone activity.

    Science.gov (United States)

    Darby, Stephen E; Hackney, Christopher R; Leyland, Julian; Kummu, Matti; Lauri, Hannu; Parsons, Daniel R; Best, James L; Nicholas, Andrew P; Aalto, Rolf

    2016-11-10

    The world's rivers deliver 19 billion tonnes of sediment to the coastal zone annually, with a considerable fraction being sequestered in large deltas, home to over 500 million people. Most (more than 70 per cent) large deltas are under threat from a combination of rising sea levels, ground surface subsidence and anthropogenic sediment trapping, and a sustainable supply of fluvial sediment is therefore critical to prevent deltas being 'drowned' by rising relative sea levels. Here we combine suspended sediment load data from the Mekong River with hydrological model simulations to isolate the role of tropical cyclones in transmitting suspended sediment to one of the world's great deltas. We demonstrate that spatial variations in the Mekong's suspended sediment load are correlated (r = 0.765, P sediment load reaching the delta is delivered by runoff generated by rainfall associated with tropical cyclones. Furthermore, we estimate that the suspended load to the delta has declined by 52.6 ± 10.2 megatonnes over recent years (1981-2005), of which 33.0 ± 7.1 megatonnes is due to a shift in tropical-cyclone climatology. Consequently, tropical cyclones have a key role in controlling the magnitude of, and variability in, transmission of suspended sediment to the coast. It is likely that anthropogenic sediment trapping in upstream reservoirs is a dominant factor in explaining past, and anticipating future, declines in suspended sediment loads reaching the world's major deltas. However, our study shows that changes in tropical-cyclone climatology affect trends in fluvial suspended sediment loads and thus are also key to fully assessing the risk posed to vulnerable coastal systems.

  10. IDRC in Vietnam

    International Development Research Centre (IDRC) Digital Library (Canada)

    credible links to policymakers and development practitioners. VERN research findings appear in the coun- try's Human Development Report and its results informed trade policy, includ- ing preparation for Vietnam's accession to the World Trade Organization. Better use of resources. IDRC support since the early 1990s has.

  11. Climate Change and Vietnam

    Science.gov (United States)

    2013-11-01

    suggests, such action may come at a cost against competing priorities like modernization and economic development. In that context, it bears inquiring...program including India, 29 Rajaram Panda , “Vietnam and the World: Focus on the U.S. and India

  12. Project CHECO Southeast Asia Report. Aerial Protection of Mekong River Convoys in Cambodia

    National Research Council Canada - National Science Library

    Mitchell, William A

    1971-01-01

    ...) shortages in the Khmer Republic (Cambodia) which had resulted from successful enemy attacks on commercial shipping vessels sailing the Mekong River inside Cambodia These attacks, combined with the closure of land Route 4 from the port city...

  13. Biofuels production for smallholder producers in the Greater Mekong Sub-region

    International Nuclear Information System (INIS)

    Malik, Urooj S.; Ahmed, Mahfuz; Sombilla, Mercedita A.; Cueno, Sarah L.

    2009-01-01

    Looming concerns on rising food prices and food security has slowed down the impetus in biofuel production. The development of the sub-sector, however, remains an important agenda among developing countries like those of the Greater Mekong Sub-region (GMS) that have abundant labour and natural resources but have limited supply of fossil fuels which continues to serve as a constraint to economic growth. Five crops have been selected to be further developed and use for biofuel production in the GMS, namely sugarcane, cassava, oil palm, sweet sorghum and Jathropa curcas. The expanded use of sugarcane, cassava, and oil palm for biofuel production can cause problems in the food sector. The other two crops, sweet sorghum and J. curcas, are non-food crops but could still compete with the food crops in terms of resource use for production. In all cases, the GMS needs to formulate a sustainable strategy for the biofuel development that will not compete with the food sector but will rather help achieve energy security, promote rural development and protect the environment. Except for People's Republic of China (PRC) and Thailand that already have fairly developed biofuel sub-sector, the other GMS countries are either poised to start (Lao PDR and Cambodia) or ready to enhance existing initiatives on biofuel production (Myanmar and Vietnam), with support from their respective governments. Biofuel development in these countries has to be strongly integrated with smallholder producers in order to have an impact on improving livelihood. At this initial stage, the sub-sector does not need to compete on a price basis but should rather aim to put up small-scale biofuel processing plants in remote rural areas that can offer an alternative to high-priced diesel and kerosene for local electricity grids serving homes and small enterprises. The social and economic multiplier effects are expected to be high when farmers that produce the energy crops also produce the biofuels to generate

  14. Biofuels production for smallholder producers in the Greater Mekong Sub-region

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Urooj S.; Ahmed, Mahfuz [Southeast Asia Department, Asian Development Bank, 6 ADB Avenue, Mandaluyong City 1550 (Philippines); Sombilla, Mercedita A. [Southeast Asian Center for Graduate Studies and Research in Agriculture (SEARCA), Consulting Services Department, 4031 College, Laguna (Philippines); Cueno, Sarah L. [Agricultural Economist and Regional Program Coordinator Greater Mekong Subregion Economic Cooperation Program Working Group on Agriculture, Southeast Asia Department, Asian Development Bank, 6 ADB Avenue, Mandaluyong City 1550 (Philippines)

    2009-11-15

    Looming concerns on rising food prices and food security has slowed down the impetus in biofuel production. The development of the sub-sector, however, remains an important agenda among developing countries like those of the Greater Mekong Sub-region (GMS) that have abundant labour and natural resources but have limited supply of fossil fuels which continues to serve as a constraint to economic growth. Five crops have been selected to be further developed and use for biofuel production in the GMS, namely sugarcane, cassava, oil palm, sweet sorghum and Jathropa curcas. The expanded use of sugarcane, cassava, and oil palm for biofuel production can cause problems in the food sector. The other two crops, sweet sorghum and J. curcas, are non-food crops but could still compete with the food crops in terms of resource use for production. In all cases, the GMS needs to formulate a sustainable strategy for the biofuel development that will not compete with the food sector but will rather help achieve energy security, promote rural development and protect the environment. Except for People's Republic of China (PRC) and Thailand that already have fairly developed biofuel sub-sector, the other GMS countries are either poised to start (Lao PDR and Cambodia) or ready to enhance existing initiatives on biofuel production (Myanmar and Vietnam), with support from their respective governments. Biofuel development in these countries has to be strongly integrated with smallholder producers in order to have an impact on improving livelihood. At this initial stage, the sub-sector does not need to compete on a price basis but should rather aim to put up small-scale biofuel processing plants in remote rural areas that can offer an alternative to high-priced diesel and kerosene for local electricity grids serving homes and small enterprises. The social and economic multiplier effects are expected to be high when farmers that produce the energy crops also produce the biofuels to

  15. Precipitation estimates and comparison of satellite rainfall data to in situ rain gauge observations to further develop the watershed-modeling capabilities for the Lower Mekong River Basin

    Science.gov (United States)

    Dandridge, C.; Lakshmi, V.; Sutton, J. R. P.; Bolten, J. D.

    2017-12-01

    This study focuses on the lower region of the Mekong River Basin (MRB), an area including Burma, Cambodia, Vietnam, Laos, and Thailand. This region is home to expansive agriculture that relies heavily on annual precipitation over the basin for its prosperity. Annual precipitation amounts are regulated by the global monsoon system and therefore vary throughout the year. This research will lead to improved prediction of floods and management of floodwaters for the MRB. We compare different satellite estimates of precipitation to each other and to in-situ precipitation estimates for the Mekong River Basin. These comparisons will help us determine which satellite precipitation estimates are better at predicting precipitation in the MRB and will help further our understanding of watershed-modeling capabilities for the basin. In this study we use: 1) NOAA's PERSIANN daily 0.25° precipitation estimate Climate Data Record (CDR), 2) NASA's Tropical Rainfall Measuring Mission (TRMM) daily 0.25° estimate, and 3) NASA's Global Precipitation Measurement (GPM) daily 0.1 estimate and 4) 488 in-situ stations located in the lower MRB provide daily precipitation estimates. The PERSIANN CDR precipitation estimate was able to provide the longest data record because it is available from 1983 to present. The TRMM precipitation estimate is available from 2000 to present and the GPM precipitation estimates are available from 2015 to present. It is for this reason that we provide several comparisons between our precipitation estimates. Comparisons were done between each satellite product and the in-situ precipitation estimates based on geographical location and date using the entire available data record for each satellite product for daily, monthly, and yearly precipitation estimates. We found that monthly PERSIANN precipitation estimates were able to explain up to 90% of the variability in station precipitation depending on station location.

  16. Adaptive Delta Management: cultural aspects of dealing with uncertainty

    Science.gov (United States)

    Timmermans, Jos; Haasnoot, Marjolijn; Hermans, Leon; Kwakkel, Jan

    2016-04-01

    Hofstede's (1983) cultural dimensions, of which uncertainty avoidance and long-term orientation are of particular relevance for our analysis. Our conclusions comment on the suitability of approaches in Adaptive Delta Management rooted in different management theories are more suitable for specific delta countries than others. The most striking conclusion is the unsuitability of rational policy analytic approaches for The Netherlands. Although surprising this conclusion finds some support in the process dominated approach taken in the Dutch Delta Program. In addition, the divergence between Vietnam, Bangladesh and Myanmar, all located in South East Asia, is striking. References Hofstede, G. (1983). The cultural relativity of organizational practices and theories. Journal of international business studies, 75-89. Jos Timmermans, Marjolijn Haasnoot, Leon Hermans, Jan Kwakkel, Martine Rutten and Wil Thissen (2015). Adaptive Delta Management: Roots and Branches, IAHR The Hague 2015.

  17. Greenhouse gas emissions of hydropower in the Mekong River Basin

    Science.gov (United States)

    Räsänen, Timo A.; Varis, Olli; Scherer, Laura; Kummu, Matti

    2018-03-01

    The Mekong River Basin in Southeast Asia is undergoing extensive hydropower development, but the magnitudes of related greenhouse gas emissions (GHG) are not well known. We provide the first screening of GHG emissions of 141 existing and planned reservoirs in the basin, with a focus on atmospheric gross emissions through the reservoir water surface. The emissions were estimated using statistical models that are based on global emission measurements. The hydropower reservoirs (119) were found to have an emission range of 0.2-1994 kg CO2e MWh-1 over a 100 year lifetime with a median of 26 kg CO2e MWh-1. Hydropower reservoirs facilitating irrigation (22) had generally higher emissions reaching over 22 000 kg CO2e MWh-1. The emission fluxes for all reservoirs (141) had a range of 26-1813 000 t CO2e yr-1 over a 100 year lifetime with a median of 28 000 t CO2e yr-1. Altogether, 82% of hydropower reservoirs (119) and 45% of reservoirs also facilitating irrigation (22) have emissions comparable to other renewable energy sources (equalling even the emission from fossil fuel power plants (>380 kg CO2e MWh-1). These results are tentative and they suggest that hydropower in the Mekong Region cannot be considered categorically as low-emission energy. Instead, the GHG emissions of hydropower should be carefully considered case-by-case together with the other impacts on the natural and social environment.

  18. Deliberation and Scale in Mekong Region Water Governance

    Science.gov (United States)

    Dore, John; Lebel, Louis

    2010-07-01

    Understanding the politics of deliberation, scales, and levels is crucial to understanding the social complexity of water-related governance. Deliberative processes might complement and inform more conventional representational and bureaucratic approaches to planning and decision-making. However, they are also subject to scale and level politics, which can confound institutionalized decision-making. Scale and level contests arise in dialogues and related arenas because different actors privilege particular temporal or spatial scales and levels in their analysis, arguments, and responses. Scale contests might include whether to privilege administrative, hydrological, ecosystem, or economic boundaries. Level contests might include whether to privilege the subdistrict or the province, the tributary watershed or the international river basin, a river or a biogeographic region, and the local or the regional economy. In the Mekong Region there is a recurrent demand for water resources development projects and major policies proposed by governments and investors to be scrutinized in public. Deliberative forms of engagement are potentially very helpful because they encourage supporters and critics to articulate assumptions and reasoning about the different opportunities and risks associated with alternative options, and in doing so, they often traverse and enable higher-quality conversations within and across scales and within and between levels. Six case studies from the Mekong Region are examined. We find evidence that scale and level politics affects the context, process, content, and outcomes of deliberative engagement in a region where public deliberation is still far from being a norm, particularly where there are sensitive and far-reaching choices to be made about water use and energy production.

  19. The Vietnam War

    DEFF Research Database (Denmark)

    Godbolt, James; Larsen, Chris Holmsted; Rasmussen, Søren Hein

    2009-01-01

    This article investigates the role of the Vietnam War in Danish and Norwegian politics. We argue that Danish and Norwegian membership in NATO and an unstable parliamentary situation may explain why these countries, unlike Sweden, did not take on the lead in the international protest against the war....... Non-socialistic coalitions came to power in Norway and Denmark in the latter half of the 1960s which to an extent explains why the social democratic parties in both countries became more critical of the US. By the end of the 1960s, foreign policy as well as public attitudes towards the war converged...... in Denmark, Sweden and Norway, and in all three countries powerful protest movements emerged that were remarkably similar. The Vietnam War strengthened the left in general and promoted a leftist politics of solidarity that influenced Swedish, Danish and Norwegian foreign policy-making of the 1970s....

  20. Exploring Vietnam's oil potential

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    A brief review is given of the oil production potential in Vietnam. Since Since 1987, the country has been open to foreign investment in offshore exploration but has suffered from a US embargo on trade and economic ties. Nevertheless some exploration has occurred and twenty production sharing contracts with international oil companies has been signed. To date most of the finds have been non-commercial but optimism remains high. (U.K.)

  1. Holocene environmental changes in Red River Delta, Vietnam as ...

    Indian Academy of Sciences (India)

    63

    2VNU Key Laboratory of Geoenvironment and Climate change Response – 334 ... Keywords: Environmental change; Stable isotopes; C/N ratios; Red River ...... and Meade R H 1983 World-wide delivery of river sediment to the oceans; The.

  2. Foundations of the participatory approach in the Mekong River basin management.

    Science.gov (United States)

    Budryte, Paulina; Heldt, Sonja; Denecke, Martin

    2018-05-01

    Integrated Water Resource Management (IWRM) was acknowledged as a leading concept in the water management for the last two decades by academia, political decision-makers and experts. It strongly promotes holistic management and participatory approaches. The flexibility and adaptability of IWRM concept are especially important for large, transboundary river basins - e.g. the Mekong river basin - where natural processes and hazards, as well as, human-made "disasters" are demanding for a comprehensive approach. In the Mekong river basin, the development and especially the enforcement of one common strategy has always been a struggle. The past holds some unsuccessful experiences. In 2016 Mekong River Commission published IWRM-based Basin Development Strategy 2016-2020 and The Mekong River Commission Strategic Plan 2016-2020. They should be the main guiding document for the Mekong river development in the near future. This study analyzes how the concept of public participation resembles the original IWRM participatory approach in these documents. Therefore, IWRM criteria for public participation in international literature and official documents from the Mekong river basin are compared. As there is often a difference between "de jure" and "de facto" implementation of public participation in management concepts, the perception of local stakeholders was assessed in addition. The results of social survey give an insight if local people are aware of Mekong river basin development and present their dominant attitudes about the issue. The findings enable recommendations how to mitigate obstacles in the implementation of common development strategy. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Developing School Psychology in Vietnam

    Science.gov (United States)

    Le, Phuong; Hagans, Kristi; Powers, Kristin; Hass, Michael

    2011-01-01

    Like China, Vietnam is a communist country with increasingly capitalist economic policies. A fundamental change occurred in these policies with the enactment of Vietnam's "doi moi" (renovation) policy in 1986 that called for a "free market with socialist orientations." However, this economic modernization has inadvertently…

  4. Demystifying Poverty Measurement in Vietnam

    OpenAIRE

    Demombynes, Gabriel; Hoang Vu, Linh

    2015-01-01

    This paper provides an overview of poverty measurement issues in Vietnam for the non-specialist. Vietnam has two main approaches to measuring poverty. An income-based approach is used by the Ministry of Labor, Invalids, and Social Affairs to generate a classification used for determining anti-poverty program eligibility as well as poverty monitoring over the short term. A separate consumpt...

  5. The Lessons of the Vietnam War.

    Science.gov (United States)

    Starr, Jerold M., Ed.

    This text book on the Vietnam War is to be used in teaching high students. Each of the volume's 12 chapters is a self-contained unit on an aspect of the War. The chapters are: (1) Introduction to Vietnam: land, history, and culture; (2) America at war in Vietnam: decisions and consequences; (3) Was the Vietnam War legal? (4) who fought for the…

  6. Regional Cooperation Efforts in the Mekong River Basin: Mitigating river-related security threats and promoting regional development

    Directory of Open Access Journals (Sweden)

    Susanne Schmeier

    2009-01-01

    Full Text Available The development of international rivers is often perceived as leading to conflicts or even water wars. However, as the development of the Mekong River shows, cooperation has not only prevailed in the last decades, but River Basin Organizations (RBOs, established to mitigate river-related conflicts and/or develop the river basin, have also contributed to the emergence of more general cooperation structures, mainly by creating spill-over effects in other issue-areas, bringing cooperation to policy fields beyond the river itself. This article assesses the contribution of the Mekong River Commission (MRC and the Greater Mekong Sub-Region (GMS to the sustainable development of the Mekong Region as well as to the promotion of regional cooperation in mainland South-East Asia in general. --- Die Entwicklung grenzüberschreitender Flüsse wird oft mit Konflikten oder gar Kriegen um Wasser assoziiert. Wie jedoch die Entwicklung im Mekong-Becken zeigt, waren die vergangenen Jahrzehnte nicht nur von Kooperation gezeichnet, sondern Flussbeckenorganisationen konnten außerdem dazu beitragen, weitreichendere Kooperationsstrukturen zu entwickeln, die sich auf andere Politikfelder ausdehnen. Dieser Artikel beschäftigt sich mit dem Beitrag der Mekong River Commission (MRC und der Greater Mekong Sub-Region (GMS zur nachhaltigen Entwicklung in der Mekong Region sowie zur Förderung allgemeiner regionaler Kooperation im Festländischen Südostasien.

  7. Temporal and Spatial Trend of Climate Variability in Vietnam

    OpenAIRE

    Duc Luong Nguyen

    2014-01-01

    Vietnam’s long coastline, geographic location, and diverse topography and climates contribute to its being one of the most hazard-prone countries of the Asia-Pacific region. Given that a high proportion of the country’s population and economic assets are located in coastal lowlands and deltas, Vietnam has been ranked among the five countries likely to be most affected by global climate change. This paper aims at providing a short overview on the temporal and spatial trends of climate variabil...

  8. Armor in Vietnam

    Science.gov (United States)

    1976-05-01

    battles a-Riuot the insurgent enemy, especially with armor. French contingents were present in Tndo Chinh P-w early as 1852, but it was not until 1884...committed to Vietnam were straight infantry. These troons er•A tran -norted in hn4±{ copters and usually airlifted to the battle zone; however, once...0STAINf0 FROM VKTNAM NATIONAL MAP SERVICE (NOS) PHU-YEN OCTOBER 19665 OARLAC ......... KKAN1+ HOA QLWA- DUC TUYEN- DUC PHUOC- NINH_ C;ry OF -10 T CAM RANK TAY

  9. Rural Credit in Vietnam

    DEFF Research Database (Denmark)

    Barslund, Mikkel Christoffer; Tarp, Finn

    This paper uses a survey of 932 rural households to uncover how the rural credit market operates in four provinces of Vietnam. Households obtain credit through formal and informal lenders, but formal loans are almost entirely for production and asset accumulation. Interest rates fell from 1997...... to 2002, reflecting increased market integration; but the determinants of formal and informal credit demand are distinct. Credit rationing depends on education and credit history, but we find no evidence of a bias against women. Regional differences are striking, and a ‘one size fits all’ approach...... to credit policy is clearly inappropriate....

  10. EU and Vietnam

    DEFF Research Database (Denmark)

    Kokko, Ari

    during most of the period since the early 1990s, when aid flows from the EU started growing. Regarding trade relations, we note that the EU’s increasing use of antidumping tariffs against Vietnamese exporters during the past years could be an indication of a less friendly and more competitive attitude...... was limited to aid. The reason is largely Vietnam’s historical experiences from the aid relationship with the Soviet Union, which created dependence and eventually an economic crisis when aid flows dried up in the late 1980s. Instead, there has been substantial tension between the donor community and Vietnam...

  11. Delta Plaza kohvik = Delta Plaza cafe

    Index Scriptorium Estoniae

    2010-01-01

    Tallinnas Pärnu mnt 141 asuva kohviku Delta Plaza sisekujundusest. Sisearhitektid Tiiu Truus ja Marja Viltrop (Stuudio Truus OÜ). Tiiu Truusi tähtsamate tööde loetelu. Büroohoone Delta Plaza arhitektid Marika Lõoke ja Jüri Okas (AB J. Okas & M. Lõoke)

  12. delta-vision

    Data.gov (United States)

    California Natural Resource Agency — Delta Vision is intended to identify a strategy for managing the Sacramento-San Joaquin Delta as a sustainable ecosystem that would continue to support environmental...

  13. Non-Traditional Security: The Case of Water Security in the Mekong Subregion

    Directory of Open Access Journals (Sweden)

    Haefner, Andrea

    2013-09-01

    Full Text Available In the first decade of the twenty-first century Non-Traditional Security (NTS challenges are of rising importance due to their increasing impact on daily life and broader national interests. This paper focuses on the Mekong Region as an important subregion due to its significance for more than 70 million people living directly on the river banks and its importance for the economic development of the six riparian countries. This paper investigates NTS challenges in the Mekong Subregion with a focus on environmental challenges and argues that NTS are of increasing importance in the region and will increase in the future. Whereas economic growth is crucial for the improvements of the livelihoods on the Mekong River and the overall economic performance of the riparian states, environmental protection cannot be disregarded as doing so would have devastating impact on the subregion and the wider region in the future.

  14. Decadal water quality variations at three typical basins of Mekong, Murray and Yukon

    Science.gov (United States)

    Khan, Afed U.; Jiang, Jiping; Wang, Peng

    2018-02-01

    Decadal distribution of water quality parameters is essential for surface water management. Decadal distribution analysis was conducted to assess decadal variations in water quality parameters at three typical watersheds of Murray, Mekong and Yukon. Right distribution shifts were observed for phosphorous and nitrogen parameters at the Mekong watershed monitoring sites while left shifts were noted at the Murray and Yukon monitoring sites. Nutrients pollution increases with time at the Mekong watershed while decreases at the Murray and Yukon watershed monitoring stations. The results implied that watershed located in densely populated developing area has higher risk of water quality deterioration in comparison to thinly populated developed area. The present study suggests best management practices at watershed scale to modulate water pollution.

  15. Pharmacy Education in Vietnam

    Science.gov (United States)

    Bedouch, Pierrick; Nguyen, Thi-Hoai; Nguyen, Thi-Lien-Huong; Hoang, Thi-Kim-Huyen; Calop, Jean; Allenet, Benoît

    2013-01-01

    Pharmacy education programs in Vietnam are complex and offer various career pathways. All include theory and laboratory modules in general, foundation, and pharmaceutical knowledge; placements in health facilities; and a final examination. The various pharmacy degree programs allow specialization in 1 or more of 5 main fields: (1) drug management and supply, (2) drug development and production, (3) pharmacology and clinical pharmacy, (4) traditional medicine and pharmacognosy, and (5) drug quality control, which are offered as main specialization options during the reformed undergraduate and postgraduate programs. However, pharmacy education in Vietnam in general remains product oriented and clinical pharmacy training has not received adequate attention. Only students who have obtained the bachelor of pharmacy degree, which requires a minimum of 5 years of study, are considered as fully qualified pharmacists. In contrast, an elementary diploma in pharmacy awarded after 1 year of pharmacy study permits entry into more junior pharmacy positions. Since the 2000s, there has been a surge in the number and types of schools offering pharmacy qualifications at various levels. PMID:23966717

  16. Demographic collapse and low genetic diversity of the Irrawaddy dolphin population inhabiting the Mekong River.

    Science.gov (United States)

    Krützen, Michael; Beasley, Isabel; Ackermann, Corinne Y; Lieckfeldt, Dietmar; Ludwig, Arne; Ryan, Gerard E; Bejder, Lars; Parra, Guido J; Wolfensberger, Rebekka; Spencer, Peter B S

    2018-01-01

    In threatened wildlife populations, it is important to determine whether observed low genetic diversity may be due to recent anthropogenic pressure or the consequence of historic events. Historical size of the Irrawaddy dolphin (Orcaella brevirostris) population inhabiting the Mekong River is unknown and there is significant concern for long-term survival of the remaining population as a result of low abundance, slow reproduction rate, high neonatal mortality, and continuing anthropogenic threats. We investigated population structure and reconstructed the demographic history based on 60 Irrawaddy dolphins samples collected between 2001 and 2009. The phylogenetic analysis indicated reciprocal monophyly of Mekong River Orcaella haplotypes with respect to haplotypes from other populations, suggesting long-standing isolation of the Mekong dolphin population from other Orcaella populations. We found that at least 85% of all individuals in the two main study areas: Kratie and Stung Treng, bore the same mitochondrial haplotype. Out of the 21 microsatellite loci tested, only ten were polymorphic and exhibited very low levels of genetic diversity. Both individual and frequency-based approaches suggest very low and non-significant genetic differentiation of the Mekong dolphin population. Evidence for recent bottlenecks was equivocal. Some results suggested a recent exponential decline in the Mekong dolphin population, with the current size being only 5.2% of the ancestral population. In order for the Mekong dolphin population to have any potential for long-term survival, it is imperative that management priorities focus on preventing any further population fragmentation or genetic loss, reducing or eliminating anthropogenic threats, and promoting connectivity between all subpopulations.

  17. Hydropower generation, flood control and dam cascades: A national assessment for Vietnam

    Science.gov (United States)

    Nguyen-Tien, Viet; Elliott, Robert J. R.; Strobl, Eric A.

    2018-05-01

    Vietnam is a country with diverse terrain and climatic conditions and a dependency on hydropower for a significant proportion of its power needs and as such, is particularly vulnerable to changes in climate. In this paper we apply SWAT (Soil and Water Assessment Tool) derived discharge simulation results coupled with regression analysis to estimate the performance of hydropower plants for Vietnam between 1995 and mid-2014 when both power supply and demand increased rapidly. Our approach is to examine the watershed formed from three large inter-boundary basins: The Red River, the Vietnam Coast and the Lower Mekong River, which have a total area of 977,964 km2. We then divide this area into 7,887 sub-basins with an average area of 131.6 km2 (based on level 12 of HydroSHEDS/HydroBASINS datasets) and 53,024 Hydrological Response Units (HRUs). Next we simulate river flow for the 40 largest hydropower plants across Vietnam. Our validation process demonstrates that the simulated flows are significantly correlated with the gauged inflows into these dams and are able to serve as a good proxy for the inflows into hydropower dams in our baseline energy regression, which captures 87.7% of the variation in monthly power generation. In other results we estimate that large dams sacrifice on average around 18.2% of their contemporaneous production for the purpose of flood control. When we assess Vietnam's current alignment of dams we find that the current cascades of large hydropower dams appear to be reasonably efficient: each MWh/day increase in upstream generation adds 0.146 MWh/day to downstream generation. The study provides evidence for the multiple benefits of a national system of large hydropower dams using a cascade design. Such a system may help overcome future adverse impacts from changes in climate conditions. However, our results show that there is still room for improvement in the harmonization of cascades in some basins. Finally, possible adverse hydro

  18. EMergy analysis perspectives of Thailand and Mekong River dam proposals

    International Nuclear Information System (INIS)

    Brown, M.T.; McClanahan, T.R.

    1996-01-01

    Methods of EMergy analysis (a scientifically based measure of wealth with units of solar emjoules (sej)) are explained and illustrated, using the economy of Thailand and two proposed dams on the Mekong River. Thailand's EMergy/$ ratio is near the world average (3.46 ·10 12 sej/$), its EMergy per capita ratio (2.98·10 15 sej/capita) is low compared to developed economies (that of the United States is 29.3·10 15 sej/capita), and its EMergy balance of payments is negative (the EMergy in exports is almost twice the EMergy in imports). The calculated net yield ratios of the proposed dams were sensitive to the treatment of sediments. The analysis yielded high net yield ratios (12.3/1 and 20.3/1) if sediments were not included, but yielded ratios of only 1.4/1 and 1.3/1 if sediments were included. If the two dams were constructed as a cascade, the combined net yield ratio was 2.5/1 (sediments included). If compared to conventional fossil fuels as a primary source of energy to the economy, the net yield ratio of the electricity generated from the two-dam cascade expressed as fossil fuels was 7.4/1

  19. Model-Aided Altimeter-Based Water Level Forecasting System in Mekong River

    Science.gov (United States)

    Chang, C. H.; Lee, H.; Hossain, F.; Okeowo, M. A.; Basnayake, S. B.; Jayasinghe, S.; Saah, D. S.; Anderson, E.; Hwang, E.

    2017-12-01

    Mekong River, one of the massive river systems in the world, has drainage area of about 795,000 km2 covering six countries. People living in its drainage area highly rely on resources given by the river in terms of agriculture, fishery, and hydropower. Monitoring and forecasting the water level in a timely manner, is urgently needed over the Mekong River. Recently, using TOPEX/Poseidon (T/P) altimetry water level measurements in India, Biancamaria et al. [2011] has demonstrated the capability of an altimeter-based flood forecasting system in Bangladesh, with RMSE from 0.6 - 0.8 m for lead times up to 5 days on 10-day basis due to T/P's repeat period. Hossain et al. [2013] further established a daily water level forecasting system in Bangladesh using observations from Jason-2 in India and HEC-RAS hydraulic model, with RMSE from 0.5 - 1.5 m and an underestimating mean bias of 0.25 - 1.25 m. However, such daily forecasting system relies on a collection of Jason-2 virtual stations (VSs) to ensure frequent sampling and data availability. Since the Mekong River is a meridional river with few number of VSs, the direct application of this system to the Mekong River becomes challenging. To address this problem, we propose a model-aided altimeter-based forecasting system. The discharge output by Variable Infiltration Capacity hydrologic model is used to reconstruct a daily water level product at upstream Jason-2 VSs based on the discharge-to-level rating curve. The reconstructed daily water level is then used to perform regression analysis with downstream in-situ water level to build regression models, which are used to forecast a daily water level. In the middle reach of the Mekong River from Nakhon Phanom to Kratie, a 3-day lead time forecasting can reach RMSE about 0.7 - 1.3 m with correlation coefficient around 0.95. For the lower reach of the Mekong River, the water flow becomes more complicated due to the reversal flow between the Tonle Sap Lake and the Mekong River

  20. New Geographical Insights of the Latest Expansion of Fusarium oxysporum f.sp. cubense Tropical Race 4 Into the Greater Mekong Subregion

    Directory of Open Access Journals (Sweden)

    Si-Jun Zheng

    2018-04-01

    Full Text Available Banana is the most popular and most exported fruit and also a major food crop for millions of people around the world. Despite its importance and the presence of serious disease threats, research into this crop is limited. One of those is Panama disease or Fusarium wilt. In the previous century Fusarium wilt wiped out the “Gros Michel” based banana industry in Central America. The epidemic was eventually quenched by planting “Cavendish” bananas. However, 50 years ago the disease recurred, but now on “Cavendish” bananas. Since then the disease has spread across South-East Asia, to the Middle-East and the Indian subcontinent and leaped into Africa. Here, we report the presence of Fusarium oxysporum f.sp. cubense Tropical Race 4 (Foc TR4 in “Cavendish” plantations in Laos, Myanmar, and Vietnam. A combination of classical morphology, DNA sequencing, and phenotyping assays revealed a very close relationship between the Foc TR4 strains in the entire Greater Mekong Subregion (GMS, which is increasingly prone to intensive banana production. Analyses of single-nucleotide polymorphisms enabled us to initiate a phylogeography of Foc TR4 across three geographical areas—GMS, Indian subcontinent, and the Middle East revealing three distinct Foc TR4 sub-lineages. Collectively, our data place these new incursions in a broader agroecological context and underscore the need for awareness campaigns and the implementation of validated quarantine measures to prevent further international dissemination of Foc TR4.

  1. Vietnam; Poverty Reduction Strategy Paper

    OpenAIRE

    International Monetary Fund

    2004-01-01

    This paper assesses the Poverty Reduction Strategy Paper of Vietnam, known as the Comprehensive Poverty Reduction and Growth Strategy (CPRGS). It is an action program to achieve economic growth and poverty reduction objectives. This paper reviews the objectives and tasks of socio-economic development and poverty reduction. The government of Vietnam takes poverty reduction as a cutting-through objective in the process of country socio-economic development and declares its commitment to impleme...

  2. Deviance and resistance: Malaria elimination in the greater Mekong subregion.

    Science.gov (United States)

    Lyttleton, Chris

    2016-02-01

    Malaria elimination rather than control is increasingly globally endorsed, requiring new approaches wherein success is not measured by timely treatment of presenting cases but eradicating all presence of infection. This shift has gained urgency as resistance to artemisinin-combination therapies spreads in the Greater Mekong Sub-region (GMS) posing a threat to global health security. In the GMS, endemic malaria persists in forested border areas and elimination will require calibrated approaches to remove remaining pockets of residual infection. A new public health strategy called 'positive deviance' is being used to improve health promotion and community outreach in some of these zones. However, outbreaks sparked by alternative understandings of appropriate behaviour expose the unpredictable nature of 'border malaria' and difficulties eradication faces. Using a recent spike in infections allegedly linked to luxury timber trade in Thai borderlands, this article suggests that opportunities for market engagement can cause people to see 'deviance' as a means to material advancement in ways that increase disease vulnerability. A malaria outbreak in Ubon Ratchathani was investigated during two-week field-visit in November 2014 as part of longer project researching border malaria in Thai provinces. Qualitative data were collected in four villages in Ubon's three most-affected districts. Discussions with villagers focused primarily on changing livelihoods, experience with malaria, and rosewood cutting. Informants included ten men and two women who had recently overnighted in the nearby forest. Data from health officials and villagers are used to frame Ubon's rise in malaria transmission within moral and behavioural responses to expanding commodity supply-chains. The article argues that elimination strategies in the GMS must contend with volatile outbreaks among border populations wherein 'infectiousness' and 'resistance' are not simply pathogen characteristics but also

  3. Profile of Vietnam War Veterans (2015).

    Data.gov (United States)

    Department of Veterans Affairs — The Profile of Vietnam War Veterans uses the 2015 ACS to provide a view into the demographic characteristics and socioeconomic conditions of the Vietnam War Veteran...

  4. Future changes in Mekong River hydrology: impact of climate change and reservoir operation on discharge

    NARCIS (Netherlands)

    Lauri, H.; de Moel, H.; Ward, P.J.; Räsänen, T.A.; Keskinen, M.; Kummu, M.S.

    2012-01-01

    The transboundary Mekong River is facing two ongoing changes that are expected to significantly impact its hydrology and the characteristics of its exceptional flood pulse. The rapid economic development of the riparian countries has led to massive plans for hydropower construction, and projected

  5. Basin-wide impacts of climate change on ecosystem services in the Lower Mekong Basin

    Science.gov (United States)

    Water resources support more than 60 million people in the Lower Mekong Basin (LMB) and are important for food security—especially rice production—and economic security. This study aims to quantify water yield under near- and long-term climate scenarios and assess the...

  6. Study on nuclear power introduction into Vietnam

    International Nuclear Information System (INIS)

    Vuong Huu Tan

    2000-01-01

    The report presents main results of the study on nuclear power introduction into Vietnam which have been carried out at Vietnam Atomic Energy Commission in collaboration with Ministry of Industry of Vietnam and other countries like Japan, Canada and Korea. The study covers all topics related to the nuclear power introduction into Vietnam such as electricity demands and supply, economics, finance, technology, safety, manpower, site selection etc. (author)

  7. Delta antibody radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Kselikova, M; Urbankova, J

    1985-11-15

    The principle and procedure are described of the radioimmunoassay of delta antibody (delta-Ab) using the ABBOTT ANTI-DELTA kit by Abbott Co. A description is given of the kit, the working procedure and the method of evaluation. The results are reported of the incidence of delta-Ab in sera of patients with viral hepatitis B, in haemophiliacs, carriers of the hepatitis B virus surface antigen (HBsAg) and blood donors. The presence was detected of delta-Ab in one HBsAg carrier. The necessity is emphasized of delta-Ab determinations in the blood of donors in view of the antibody transfer with blood and blood preparations.

  8. 77 FR 20273 - Vietnam Veterans Day

    Science.gov (United States)

    2012-04-03

    ... showing a generation of veterans the respect and support of a grateful Nation. The Vietnam War is a story... with honor, and on March 29, 1973, the last of our troops left Vietnam. Yet, in one of the war's most... commemorate the 50-year anniversary of the Vietnam War. [[Page 20276

  9. Mahseers genera Tor and Neolissochilus (Teleostei: Cyprinidae) from southern Vietnam.

    Science.gov (United States)

    Hoàng, Huy Đức; Phạm, Hùng Mạnh; Durand, Jean-Dominique; Trần, Ngân Trọng; Phan, Phúc Đình

    2015-08-25

    Two new species and two new basin records of mahseers in the genera Tor and Neolissochilus are described from the upper Krong No and middle Đồng Nai drainages of the Langbiang Plateau in southern Vietnam. These new species and new records are known from streams and rivers in montane mixed pine and evergreen forests between 140 and 1112 m. Their populations are isolated in the Sre Pok River of the Mekong basin, the middle of the Đồng Nai basin, and the An Lão River. Both new species are differentiated from their congeners by a combination of the following characters: 23-24 lateral scales, 9-10 predorsal scales, 2/7 or 1/8 pelvic-fin rays, mouth position, median lobe of lower lip, rostral hood, colour in life and by divergent mitochondrial DNA. Tor mekongensis sp. nov. is differentiated from Tor dongnaiensis sp. nov. by the number of transverse scale rows (3/1/2 vs. 4/1/2), number of pelvic-fin rays (2/7 vs. 1/8), a blunt rostral hood vs. pointed, caudal-fin lobes that are equal vs. unequal, and by mitochondrial DNA (0.7% sequence divergence). Molecular evidence identifies both species as members of the genus Tor and distinct from all congeners sampled (uncorrected sequence divergences >1.9% for all Tor species for which homologous COI sequences are available). Tor sinensis is recorded in the Krong No and the Sre Pok rivers, further south of its known distribution. Polymorphism is described in Neolissochilus stracheyi with a Tor-like morph and a Neolissochilus-like morph.

  10. Delta hedging strategies comparison

    DEFF Research Database (Denmark)

    De Giovanni, Domenico; Ortobelli, S.; Rachev, S.T.

    2008-01-01

    In this paper we implement dynamic delta hedging strategies based on several option pricing models. We analyze different subordinated option pricing models and we examine delta hedging costs using ex-post daily prices of S&P 500. Furthermore, we compare the performance of each subordinated model...

  11. Connectivity in river deltas

    Science.gov (United States)

    Passalacqua, P.; Hiatt, M. R.; Sendrowski, A.

    2016-12-01

    Deltas host approximately half a billion people and are rich in ecosystem diversity and economic resources. However, human-induced activities and climatic shifts are significantly impacting deltas around the world; anthropogenic disturbance, natural subsidence, and eustatic sea-level rise are major causes of threat to deltas and in many cases have compromised their safety and sustainability, putting at risk the people that live on them. In this presentation, I will introduce a framework called Delta Connectome for studying connectivity in river deltas based on different representations of a delta as a network. Here connectivity indicates both physical connectivity (how different portions of the system interact with each other) as well as conceptual (pathways of process coupling). I will explore several network representations and show how quantifying connectivity can advance our understanding of system functioning and can be used to inform coastal management and restoration. From connectivity considerations, the delta emerges as a leaky network that evolves over time and is characterized by continuous exchanges of fluxes of matter, energy, and information. I will discuss the implications of connectivity on delta functioning, land growth, and potential for nutrient removal.

  12. Response to the 2009-H1N1 influenza pandemic in the Mekong Basin: surveys of country health leaders

    Directory of Open Access Journals (Sweden)

    Dausey David J

    2011-09-01

    Full Text Available Abstract Background Soon after the 2009-H1N1 virus emerged as the first influenza pandemic in 41 years, countries had an early opportunity to test their preparedness plans, protocols and procedures, including their cooperation with other countries in responding to the global pandemic threat. The Mekong Basin Disease Surveillance cooperation (MBDS comprises six countries - Cambodia, China (Yunnan and Guangxi Provinces, Lao People's Democratic Republic, Myanmar, Thailand and Vietnam - that formally organized themselves in 2001 to cooperate in disease surveillance and control. The pandemic presented an opportunity to assess their responses in light of their individual and joint planning. We conducted two surveys of the MBDS leadership from each country, early during the pandemic and shortly after it ended. Results On average, participants rated their country's pandemic response performance as good in both 2009 and 2010. Post-pandemic (2010, perceived performance quality was best for facility-based interventions (overall mean of 4.2 on a scale from 1 = poor to 5 = excellent, followed by surveillance and information sharing (4.1, risk communications (3.9 and disease prevention and control in communities (3.7. Performance was consistently rated as good or excellent for use of hotlines for case reporting (2010 mean of 4.4 and of selected facility-based interventions (each with a 2010 mean of 4.4: using hospital admission criteria, preparing or using isolation areas, using PPE for healthcare workers and using antiviral drugs for treatment. In at least half the countries, the post-pandemic ratings were lower than initial 2009 assessments for performance related to surveillance, facility-based interventions and risk communications. Conclusions MBDS health leaders perceived their pandemic responses effective in areas previously considered problematic. Most felt that MBDS cooperation helped drive and thus added value to their efforts. Surveillance capacity

  13. Exploitation, Violence, and Suicide Risk Among Child and Adolescent Survivors of Human Trafficking in the Greater Mekong Subregion.

    Science.gov (United States)

    Kiss, Ligia; Yun, Katherine; Pocock, Nicola; Zimmerman, Cathy

    2015-09-01

    Human trafficking and exploitation of children have profound health consequences. To our knowledge, this study represents the largest survey on the health of child and adolescent survivors of human trafficking. To describe experiences of abuse and exploitation, mental health outcomes, and suicidal behavior among children and adolescents in posttrafficking services. We also examine how exposures to violence, exploitation, and abuse affect the mental health and suicidal behavior of trafficked children. A survey was conducted with 387 children and adolescents aged 10 to 17 years in posttrafficking services in Cambodia, Thailand, or Vietnam, which along with Laos, Myanmar, and Yunnan Province, China, compose the Greater Mekong Subregion. Participants were interviewed within 2 weeks of entering services from October 2011 through May 2013. Depression, posttraumatic stress disorder, anxiety, suicidal ideation, self-injury, and suicide attempts. Among the 387 children and adolescent study participants, most (82%) were female. Twelve percent had tried to harm or kill themselves in the month before the interview. Fifty-six percent screened positive for depression, 33% for an anxiety disorder, and 26% for posttraumatic stress disorder. Abuse at home was reported by 20%. Physical violence while trafficked was reported by 41% of boys and 19% of girls. Twenty-three percent of girls and 1 boy reported sexual violence. Mental health symptoms were strongly associated with recent self-harm and suicide attempts. Severe physical violence was associated with depression (adjusted odds ratio [AOR], 3.55; 95% CI, 1.64-7.71), anxiety (AOR, 2.13; 95% CI, 1.12-4.05), and suicidal ideation (AOR, 3.68; 95% CI, 1.77-7.67). Sexual violence while trafficked was associated with depression (AOR, 2.27; 95% CI, 1.22-4.23) and suicidal ideation (AOR, 3.43; 95% CI, 1.80-6.54). Children and adolescents in posttrafficking care showed high symptom levels of depression, anxiety, and posttraumatic stress

  14. An analysis of health system resources in relation to pandemic response capacity in the Greater Mekong Subregion

    Directory of Open Access Journals (Sweden)

    Hanvoravongchai Piya

    2012-12-01

    Full Text Available Abstract Background There is increasing perception that countries cannot work in isolation to militate against the threat of pandemic influenza. In the Greater Mekong Subregion (GMS of Asia, high socio-economic diversity and fertile conditions for the emergence and spread of infectious diseases underscore the importance of transnational cooperation. Investigation of healthcare resource distribution and inequalities can help determine the need for, and inform decisions regarding, resource sharing and mobilisation. Methods We collected data on healthcare resources deemed important for responding to pandemic influenza through surveys of hospitals and district health offices across four countries of the GMS (Cambodia, Lao PDR, Thailand, Vietnam. Focusing on four key resource types (oseltamivir, hospital beds, ventilators, and health workers, we mapped and analysed resource distributions at province level to identify relative shortages, mismatches, and clustering of resources. We analysed inequalities in resource distribution using the Gini coefficient and Theil index. Results Three quarters of the Cambodian population and two thirds of the Laotian population live in relatively underserved provinces (those with resource densities in the lowest quintile across the region in relation to health workers, ventilators, and hospital beds. More than a quarter of the Thai population is relatively underserved for health workers and oseltamivir. Approximately one fifth of the Vietnamese population is underserved for beds and ventilators. All Cambodian provinces are underserved for at least one resource. In Lao PDR, 11 percent of the population is underserved by all four resource items. Of the four resources, ventilators and oseltamivir were most unequally distributed. Cambodia generally showed higher levels of inequalities in resource distribution compared to other countries. Decomposition of the Theil index suggests that inequalities result principally from

  15. CASE STUDY: Vietnam — Information brings progress to Vietnam's ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    The WUNB is the provincial branch of the Vietnam Women's Union, a unique country-wide ... It also serves to monitor and evaluate their performance. ... Vu Thi Tan explains, detailed information is needed for the union to carry out its work.

  16. Agro-Environmental Determinants of Avian Influenza Circulation: A Multisite Study in Thailand, Vietnam and Madagascar

    Science.gov (United States)

    Paul, Mathilde C.; Gilbert, Marius; Desvaux, Stéphanie; Rasamoelina Andriamanivo, Harena; Peyre, Marisa; Khong, Nguyen Viet; Thanapongtharm, Weerapong; Chevalier, Véronique

    2014-01-01

    Outbreaks of highly pathogenic avian influenza have occurred and have been studied in a variety of ecological systems. However, differences in the spatial resolution, geographical extent, units of analysis and risk factors examined in these studies prevent their quantitative comparison. This study aimed to develop a high-resolution, comparative study of a common set of agro-environmental determinants of avian influenza viruses (AIV) in domestic poultry in four different environments: (1) lower-Northern Thailand, where H5N1 circulated in 2004–2005, (2) the Red River Delta in Vietnam, where H5N1 is circulating widely, (3) the Vietnam highlands, where sporadic H5N1 outbreaks have occurred, and (4) the Lake Alaotra region in Madagascar, which features remarkable similarities with Asian agro-ecosystems and where low pathogenic avian influenza viruses have been found. We analyzed H5N1 outbreak data in Thailand in parallel with serological data collected on the H5 subtype in Vietnam and on low pathogenic AIV in Madagascar. Several agro-environmental covariates were examined: poultry densities, landscape dominated by rice cultivation, proximity to a water body or major road, and human population density. Relationships between covariates and AIV circulation were explored using spatial generalized linear models. We found that AIV prevalence was negatively associated with distance to the closest water body in the Red River Delta, Vietnam highlands and Madagascar. We also found a positive association between AIV and duck density in the Vietnam highlands and Thailand, and with rice landscapes in Thailand and Madagascar. Our findings confirm the important role of wetlands-rice-ducks ecosystems in the epidemiology of AI in diverse settings. Variables influencing circulation of the H5 subtype in Southeast Asia played a similar role for low pathogenic AIV in Madagascar, indicating that this area may be at risk if a highly virulent strain is introduced. PMID:25029441

  17. Agro-environmental determinants of avian influenza circulation: a multisite study in Thailand, Vietnam and Madagascar.

    Science.gov (United States)

    Paul, Mathilde C; Gilbert, Marius; Desvaux, Stéphanie; Andriamanivo, Harena Rasamoelina; Peyre, Marisa; Khong, Nguyen Viet; Thanapongtharm, Weerapong; Chevalier, Véronique

    2014-01-01

    Outbreaks of highly pathogenic avian influenza have occurred and have been studied in a variety of ecological systems. However, differences in the spatial resolution, geographical extent, units of analysis and risk factors examined in these studies prevent their quantitative comparison. This study aimed to develop a high-resolution, comparative study of a common set of agro-environmental determinants of avian influenza viruses (AIV) in domestic poultry in four different environments: (1) lower-Northern Thailand, where H5N1 circulated in 2004-2005, (2) the Red River Delta in Vietnam, where H5N1 is circulating widely, (3) the Vietnam highlands, where sporadic H5N1 outbreaks have occurred, and (4) the Lake Alaotra region in Madagascar, which features remarkable similarities with Asian agro-ecosystems and where low pathogenic avian influenza viruses have been found. We analyzed H5N1 outbreak data in Thailand in parallel with serological data collected on the H5 subtype in Vietnam and on low pathogenic AIV in Madagascar. Several agro-environmental covariates were examined: poultry densities, landscape dominated by rice cultivation, proximity to a water body or major road, and human population density. Relationships between covariates and AIV circulation were explored using spatial generalized linear models. We found that AIV prevalence was negatively associated with distance to the closest water body in the Red River Delta, Vietnam highlands and Madagascar. We also found a positive association between AIV and duck density in the Vietnam highlands and Thailand, and with rice landscapes in Thailand and Madagascar. Our findings confirm the important role of wetlands-rice-ducks ecosystems in the epidemiology of AI in diverse settings. Variables influencing circulation of the H5 subtype in Southeast Asia played a similar role for low pathogenic AIV in Madagascar, indicating that this area may be at risk if a highly virulent strain is introduced.

  18. The Vietnam Experience in Perspective.

    Science.gov (United States)

    Nurse, Ronald J.; Fleming, Dan B.

    1982-01-01

    Ten recent editions of secondary school-level United States history textbooks were analyzed to determine coverage and balance of the Vietnam War. Treatment of topics such as Vietnamese culture, the roles of wartime leaders, the aims of the United States government, the antiwar movement, and costs of the war are discussed. (PP)

  19. Greening textile industry in Vietnam

    NARCIS (Netherlands)

    Nguyen Thi Phuong, L.

    2011-01-01

    The textile and garment industry has made a remarkable contribution to the economic development of Vietnam and employs currently a large labor force of 2.5 million people.However, the textile industry is also seen as a most polluting and unsustainable industry due to the use of

  20. From Combat to Legacies: Novels of the Vietnam War.

    Science.gov (United States)

    Johannessen, Larry R.

    1995-01-01

    Discusses novels of the Vietnam War, their usefulness, and the interest they hold for students. Considers four categories of Vietnam novels: the Vietnam experience, the war at home, the refugee experience, and the war's effect on the next generation. (SR)

  1. Production of Generation-2 Mekong giant catfish (Pangasinodon gigas cultured with Spirulina sp.

    Directory of Open Access Journals (Sweden)

    Kriangsak Meng-umphan

    2008-11-01

    Full Text Available The purpose of this study is to evaluate the treatment of Spirulina-supplemented pellet feed to 5-year-old F1 groups of Mekong giant catfish (Pangasinodon gigas from the brood stock and intended for use as breeders. The effects on their growth and maturation when cultured in an earthen pond were observed. Results revealed that, compared to control, there was more gain in weight while the feed conversion ratio was lower. The number of red blood cells was also higher while that of white blood cells was lower, compared to control. Out of 18 treated fish (9 males and 9 females, 6 males and 2 females gave sperms and eggs while none from control group did. It was concluded that Spirulina supplemented in pellet feed can improve growth and maturation performance to the brood stock of Mekong giant catfish.

  2. Trading-off fish biodiversity, food security, and hydropower in the Mekong River Basin.

    Science.gov (United States)

    Ziv, Guy; Baran, Eric; Nam, So; Rodríguez-Iturbe, Ignacio; Levin, Simon A

    2012-04-10

    The Mekong River Basin, site of the biggest inland fishery in the world, is undergoing massive hydropower development. Planned dams will block critical fish migration routes between the river's downstream floodplains and upstream tributaries. Here we estimate fish biomass and biodiversity losses in numerous damming scenarios using a simple ecological model of fish migration. Our framework allows detailing trade-offs between dam locations, power production, and impacts on fish resources. We find that the completion of 78 dams on tributaries, which have not previously been subject to strategic analysis, would have catastrophic impacts on fish productivity and biodiversity. Our results argue for reassessment of several dams planned, and call for a new regional agreement on tributary development of the Mekong River Basin.

  3. Flood mitigation strategies for the Red River Delta

    International Nuclear Information System (INIS)

    Hansson, K.; Ekenberg, L.

    2002-01-01

    The increase of natural disasters and especially floods are escalating economical losses. Governments of both developed and developing countries are therefore concerned with increasing post-disaster liabilities in aiding recovery, repairing infrastructure damage and compensation of victims. In particular, governments of developing countries are ill prepared to cover the financial losses of disasters. Moreover, they often experience difficulties in raising funds for the recovery process. In this article, we identify possible policy strategies for coping with complex environmental and social decisions with flood risk involved; using The Red River Delta in Vietnam as a case for investigating various strategies. The paper is concluded with an outline of a model used for policy scenario simulations as well as some very preliminary results from evaluation of three possible policy strategies for The Red River Delta. (author)

  4. Downstream on the Mekong: Contrasting Cambodian and Vietnamese Responses to Chinese Water Control

    Science.gov (United States)

    2017-06-01

    Value in the Mekong Basin ..................................48 xii THIS PAGE INTENTIONALLY LEFT BLANK xiii LIST OF ACRONYMS AND ABBREVIATIONS AFC...from 7.1 to 8.3 billion people, the report acknowledges that water may well become “a more significant source of contention than energy or minerals ...evidence of an association between [Yunnan’s] population resettlement and diminished social capital in China’s hydropower sector .”70 These negative

  5. Hydrology and morphology of two river mouth regions (temperate Vistula Delta and subtropical Red River Delta

    Directory of Open Access Journals (Sweden)

    Zbigniew Pruszak

    2005-09-01

    Full Text Available The paper presents a comparative analysis of two different river mouths from two different geographical zones (subtropical and temperate climatic regions. One is the multi-branch and multi-spit mouth of the Red River on the Gulf of Tonkin (Vietnam, the other is the smaller delta of the river Vistula on a bay of the Baltic Sea (Poland. The analysis focuses on the similarities and differences in the hydrodynamics between these estuaries and the adjacent coastal zones, the features of sediment transport, and the long-term morphodynamics of the river outlets. Salinity and water level are also discussed, the latter also in the context of the anticipated global effect of accelerated sea level rise. The analysis shows that the climatic and environmental conditions associated with geographical zones give rise to fundamental differences in the generation and dynamic evolution of the river mouths.

  6. Mineral resources of Vietnam

    Directory of Open Access Journals (Sweden)

    Kušnír Imrich

    2000-06-01

    Full Text Available Vietnam je bohatý na nerastné suroviny, ktoré sa nachádzajú prevažne na severe krajiny. Ložiská bauxitov, fosfátov, vzácnych zemín (REE, majú svetový význam. Ale i zásoby celého radu ïalších surovín (ropy, uhlia, zlata, železných rúd, chromitu, cínu, ilmenitu, medi, grafitu, atï. sú významné, ekonomicky ažite¾né a ich potenciál je obrovský. Za uvedené nerastné bohatstvo je „zodpovednᓠrozmanitá geologická stavba krajiny. Taktiež i morfológia a klíma (vlhká, tropická prispeli ku vytvoreniu niektorých ložísk (bauxity v krasových priehlbniach, atï.. Súèasná produkcia, okrem ropy (3,5 Mt/rok, zahròuje: 10,7 Mt uhlia, 3,5 Mt chromitu, asi 1 000 kg zlata, grafitu, kaolínu a mnohé iné minerály. Napriek tomu, je banícky priemysel v porovnaní so surovinovou základòou slabo vyvinutý. K jeho rozvoju urèite prispeje i úèas zahranièných spoloèností, odnedávna prítomných pri prieskume a ažbe surovín urèených pre export. Okrem struèného úvodu do geológie krajiny, obsahuje tento èlánok krátky popis nerastného bohatstva Vietnamu.

  7. The United States and Vietnam Relationship: Benefits and Challenges for Vietnam

    Science.gov (United States)

    2016-06-10

    the current stage in their bilateral relations. The U.S.-Vietnam relationship has been increasingly cemented in the context of the contemporary...reach the current stage in their bilateral relations. The U.S.-Vietnam relationship has been increasingly cemented in the context of the contemporary...Major Exports to Vietnam aircraft, mining equipment, electronic machinery, steel wire, raw cotton, plastics Source: Mark E. Manyin, The Vietnam

  8. The Niger Delta Crisis

    African Journals Online (AJOL)

    chifaou.amzat

    2013-09-28

    Sep 28, 2013 ... Department of History & International Studies, Delta State University, Abraka,. Nigeria. .... democracy implies popular power. That is ... Okonta (2006:5) draws attention to Anna Zalik's treatise called 'Petro-Vio- lence' and ...

  9. Delta agent (Hepatitis D)

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000216.htm Hepatitis D (Delta agent) To use the sharing features on this page, please enable JavaScript. Hepatitis D is a viral infection caused by the ...

  10. Delta 2.0

    DEFF Research Database (Denmark)

    Skott, Jeppe; Skott, Charlotte Krog; Jess, Kristine

    DELTA 2.0 er en ny og helt opdateret udgave af Delta, der i ti år været brugt i matematiklærernes grund-, efter- og videreuddannelse. DELTA 2.0 er seriens almene fagdidaktik. Der er også fagdidaktiske overvejelser i de øvrige bøger i serien, men de er knyttet til specifikt matematisk indhold. DELTA...... 2.0 behandler mere generelle matematikdidaktiske problemstillinger såsom læringsteoretiske overvejelser i forbindelse med matematik, centrale aspekter af det at undervise i matematik og digitale teknologier som værktøj til at støtte elevers faglige læring af matematik....

  11. Training human resource for NPP in Vietnam

    International Nuclear Information System (INIS)

    Nguyen, Trung Tinh; Dam, Xuan Hiep

    2008-01-01

    Vietnam will establish the first NPP in the near future. With us the first important thing is the human resource, but now there is no university in Vietnam training nuclear engineers. In EPU (Electric Power University), now we are preparing for training nuclear engineers. In this paper, we review the nuclear man power and the way to train the high quality human resource for NPP and for other nuclear application in Vietnam. (author)

  12. Regional trends in early-monsoon rainfall over Vietnam and CCSM4 attribution

    Science.gov (United States)

    Li, R.; Wang, S. S.-Y.; Gillies, R. R.; Buckley, B. M.; Yoon, J.-H.; Cho, C.

    2018-04-01

    The analysis of precipitation trends for Vietnam revealed that early-monsoon precipitation has increased over the past three decades but to varying degrees over the northern, central and southern portions of the country. Upon investigation, it was found that the change in early-monsoon precipitation is associated with changes in the low-level cyclonic airflow over the South China Sea and Indochina that is embedded in the large-scale atmospheric circulation associated with a "La Niña-like" anomalous sea surface temperature pattern with warming in the western Pacific and Indian Oceans and cooling in the eastern Pacific. The Community Climate System Model version 4 (CCSM4) was subsequently used for an attribution analysis. Over northern Vietnam an early-monsoon increase in precipitation is attributed to changes in both greenhouse gases and natural forcing. For central Vietnam, the observed increase in early-monsoon precipitation is reproduced by the simulation forced with greenhouse gases. However, over southern Vietnam the early-monsoon precipitation increase is less definitive where aerosols were seen to be preponderant but natural forcing through the role of the Interdecadal Pacific Oscillation may well be a factor that is not resolved by CCSM4. Increased early-monsoonal precipitation over the coastal lowland and deltas has the potential to amplify economic and human losses.

  13. Future changes in Mekong River hydrology: impact of climate change and reservoir operation on discharge

    Directory of Open Access Journals (Sweden)

    H. Lauri

    2012-12-01

    Full Text Available The transboundary Mekong River is facing two ongoing changes that are expected to significantly impact its hydrology and the characteristics of its exceptional flood pulse. The rapid economic development of the riparian countries has led to massive plans for hydropower construction, and projected climate change is expected to alter the monsoon patterns and increase temperature in the basin. The aim of this study is to assess the cumulative impact of these factors on the hydrology of the Mekong within next 20–30 yr. We downscaled the output of five general circulation models (GCMs that were found to perform well in the Mekong region. For the simulation of reservoir operation, we used an optimisation approach to estimate the operation of multiple reservoirs, including both existing and planned hydropower reservoirs. For the hydrological assessment, we used a distributed hydrological model, VMod, with a grid resolution of 5 km × 5 km. In terms of climate change's impact on hydrology, we found a high variation in the discharge results depending on which of the GCMs is used as input. The simulated change in discharge at Kratie (Cambodia between the baseline (1982–1992 and projected time period (2032–2042 ranges from −11% to +15% for the wet season and −10% to +13% for the dry season. Our analysis also shows that the changes in discharge due to planned reservoir operations are clearly larger than those simulated due to climate change: 25–160% higher dry season flows and 5–24% lower flood peaks in Kratie. The projected cumulative impacts follow rather closely the reservoir operation impacts, with an envelope around them induced by the different GCMs. Our results thus indicate that within the coming 20–30 yr, the operation of planned hydropower reservoirs is likely to have a larger impact on the Mekong hydrograph than the impacts of climate change, particularly during the dry season. On the other hand, climate change will

  14. Research on the coordination framework for water resources utilization on the interests of mutual compensation in Lancang-Mekong River

    Science.gov (United States)

    Wang, Y.; Fang, D., VI; Xu, J.; Dong, Q.

    2017-12-01

    The Lancang-Mekong River is an important international river, cascaded hydropower stations development in which attracts the attention of downstream countries. In this paper, we proposed a coordination framework for water resources utilization on the interests of mutual compensation to relieve the conflict of upstream and downstream countries. Firstly, analyze the benefits and risks caused by the cascaded hydropower stations development and the evolution process of water resources use conflict between upstream and downstream countries. Secondly, evaluate the benefits and risks of flood control, water supply, navigation and power generation based on the energy theory of cascaded hydropower stations development in Lancang-Mekong River. Thirdly, multi-agent cooperation motivation and cooperation conditions between upstream and downstream countries in Lancang-Mekong River is given. Finally, the coordination framework for water resources utilization on the interests of mutual compensation in Lancang-Mekong River is presented. This coordination framework for water resources utilization can increase comprehensive benefits in Lancang-Mekong River.

  15. Turning poop into profit: Cost-effectiveness and soil transmitted helminth infection risk associated with human excreta reuse in Vietnam

    OpenAIRE

    Tran-Thi, Ngan; Lowe, Rachel J.; Schurer, Janna M.; Vu-Van, Tu; MacDonald, Lauren E.; Pham-Duc, Phuc

    2017-01-01

    Human excreta is a low cost source of nutrients vital to plant growth, but also a source of pathogens transmissible to people and animals. We investigated the cost-savings and infection risk of soil transmitted helminths (STHs) in four scenarios where farmers used either inorganic fertilizer or fresh/composted human excreta supplemented by inorganic fertilizer to meet the nutrient requirements of rice paddies in the Red River Delta, Vietnam. Our study included two main components: 1) a risk e...

  16. Vietnam and the regional crisis

    DEFF Research Database (Denmark)

    Masina, Pietro Paolo

    2002-01-01

    inflows, should be understood in the broader frame of regional contingencies, and not be simplistically explained as investors' discontent (i.e., in order to pressure Vietnamese authorities into implementing a more orthodox neo-liberal agenda). And in a post-crisis regional economic reorganisation...... that Vietnam can successfully exploit market niches opened up by postcrisis regional economic reorganisation, thus offering some optimism for the country's immediate economic future....

  17. Freshwater Aquaculture Nurseries and Infection of Fish with Zoonotic Trematodes, Vietnam

    Science.gov (United States)

    Ersbøll, Annette Kjær; Nguyen, Thanh Thi; Nguyen, Khue Viet; Nguyen, Ha Thi; Murrell, Darwin; Dalsgaard, Anders

    2010-01-01

    Residents of the Red River Delta region of northern Vietnam have a long tradition of eating raw fish. Fish-borne zoonotic trematodes (FZTs) are estimated to infect ≈1 million persons in Vietnam. It remains uncertain at what stages in the aquaculture production cycle fish become infected with FZTs. Newly hatched fish (fry) from 8 hatcheries and juveniles from 27 nurseries were therefore examined for FZT infection. No FZTs were found in fry from hatcheries. In nurseries, FZT prevalence in juveniles was 14.1%, 48.6%, and 57.8% after 1 week, 4 weeks, and when overwintered in ponds, respectively. FZT prevalence was higher in grass carp (paquaculture management practices, particularly in nurseries, to minimize the risk of distributing infected juveniles to grow-out ponds and, subsequently, to markets for human consumption. PMID:21122220

  18. Characteristics of some traditional Vietnamese starch-based rice wine fermentation starters (men)

    NARCIS (Netherlands)

    Dung, N.T.P.; Rombouts, F.M.; Nout, M.J.R.

    2007-01-01

    In the Mekong Delta region of South-Vietnam, wine from purple glutinous rice is particularly interesting because of its sherry-like taste and flavour and its attractive brown-red colour. It is manufactured at home or by small cottage industries, using traditional solid-state starters (Men). With the

  19. Salt Intrusion, Tides and Mixing in Multi-channel Estuaries

    NARCIS (Netherlands)

    Nguyen, A.D.

    2008-01-01

    Multi-channel estuaries, such as the Mekong Delta in Vietnam and the Scheldt in the Netherlands, have characteristics of both the river and the sea, forming a unique environment influenced by tidal movements of the sea and freshwater flow of the river. This study addresses a number of knowledge gaps

  20. Defined fungal starter granules for purple glutinous rice wine

    NARCIS (Netherlands)

    Ngo Thi Phuong Dung, N.T.P.

    2004-01-01

    The Mekong Delta region ofSouth Vietnamis particularly known as a production area of purple glutinous rice wine ( RuouNepThan ). The latter differs from regular

  1. Monitoring quantity and quality of pangasius pond effluent : report of a monitoring program and recommendations for certification

    NARCIS (Netherlands)

    Heijden, van der P.G.M.; Poelman, M.; Vo Minh Son,; Duong Nhut Long,; Bosma, R.H.

    2011-01-01

    The quantity and quality of pangasius pond effluent was monitored by means of monthly sampling during a study conducted on four striped catfish farms located in the Mekong Delta, Vietnam. The study was undertaken to test the practical implications of the standards and guidelines with regard to

  2. Penaeus monodon post-larvae and their interaction with Rhizophora apiculata

    NARCIS (Netherlands)

    Nga, B.T.

    2004-01-01

    In recent years, expansion of shrimp aquaculture in Vietnam has brought considerable financial benefits to farmers and local communities. In the coastal provinces in the Mekong Delta, brackish shrimp aquaculture is the major economy activity. Extensive shrimp-mangrove culture systems are popularly

  3. Farmers' perceptions and practices in use of Dolichoderus thoracicus (Smith)(Hymenoptera: Formicidae) for biological control of pests of Sapodilla

    NARCIS (Netherlands)

    Mele, van P.; Cuc, N.T.T.

    2001-01-01

    In 1996, a majority (61%) of 190 sapodilla farmers in the Mekong Delta, Vietnam considered the black ant, Dolichoderus thoracicus (Smith), beneficial in decreasing damage by the fruit borer Alophia sp. (51%), the mealybug Planococcus lilacinus (Cockerell) (43%), and "bad" ants, notably Cardiocondyla

  4. Bentley Research Fellowship

    International Development Research Centre (IDRC) Digital Library (Canada)

    2008-04-12

    Dr Bentley passed away April 12, 2008. The 2016 Bentley Research Fellowship was awarded to Sarah Allen, PhD candidate in Geography at York University. The Fellowship supported her research entitled: Urban Water Scarcity in the Mekong River Delta, Vietnam: An Urban Political Ecology Analysis of Urbanization and ...

  5. Low numbers of repeat units in variable number of tandem repeats (VNTR) regions of white spot syndrome virus are correlated with disease outbreaks

    NARCIS (Netherlands)

    Tran Thi Tuyet, H.; Zwart, M.P.; Phuong, N.T.; Jong, de M.C.M.; Vlak, J.M.

    2012-01-01

    White spot syndrome virus (WSSV) is the most important pathogen in shrimp farming systems worldwide including the Mekong Delta, Vietnam. The genome of WSSV is characterized by the presence of two major 'indel regions' found at ORF14/15 and ORF23/24 (WSSV-Thailand) and three regions with variable

  6. Search | Page 30 | IDRC - International Development Research Centre

    International Development Research Centre (IDRC) Digital Library (Canada)

    Yet, it hasn't always been embraced by development agencies because of conflicts over water and land use, high stock losses due to disease, and ... IDRC Doctoral Research Awards (closed) | IDRC - International ... Urban Water Scarcity in the Mekong River Delta, Vietnam: An Urban Political ... Services Delivery in Africa ...

  7. Optimisation of selective breeding program for Nile tilapia (Oreochromis niloticus)

    NARCIS (Netherlands)

    Trong, T.Q.

    2013-01-01

    The aim of this thesis was to optimise the selective breeding program for Nile tilapia in the Mekong Delta region of Vietnam. Two breeding schemes, the “classic” BLUP scheme following the GIFT method (with pair mating) and a rotational mating scheme with own performance selection and

  8. Experimental nuclear physics in Vietnam - recent status

    International Nuclear Information System (INIS)

    Tran Thanh Minh

    1995-01-01

    Status of research works on experimental nuclear physics in Vietnam is reviewed. Vietnam institutions and main instruments for nuclear research are listed. The results on physics and technology of nuclear reactor, neutron physics, nuclear reactions, radiological safety are mentioned. (N.H.A). 6 tabs, 4 figs

  9. Perspectives on the Teaching of Vietnam.

    Science.gov (United States)

    Berman, David M.

    1986-01-01

    Too often seen through the lens of the United States experience in the Vietnam War, this article offers an alternative approach to teaching Vietnam through the development of a cultural and historical perspective. Provides a brief summary of literature on Vietnamese cultural history which is appropriate to high school students. (JDH)

  10. Teaching the Vietnam War: A Sociological Approach.

    Science.gov (United States)

    Starr, Jerold M.

    1995-01-01

    Maintains that, because of its importance in modern U.S. history, over 300 college courses are taught on the Vietnam War. Asserts that studying the war helps students develop critical thinking skills needed for citizenship. Describes the texts, formats, and assignments used in a college sociology course on the Vietnam War. (CFR)

  11. 45 CFR 506.10 - “Vietnam conflict” defined.

    Science.gov (United States)

    2010-10-01

    ... § 506.10 “Vietnam conflict” defined. Vietnam conflict refers to the period beginning February 28, 1961... “Vietnam conflict” for purposes of payment of interest on missing military service members' deposits in the... ending date for the Vietnam conflict for purposes of determining eligibility for compensation under 50 U...

  12. Current situation of radiation protection in Vietnam

    International Nuclear Information System (INIS)

    Tran, Toan Ngoc

    2008-01-01

    Vietnam was one of the earliest countries, who applied ionizing radiation in medicine, since 1923, Dr. Marie Curie had supplied radium sources to Hanoi cancer hospital for radiotherapy. However, we did not give sufficient attention to radiation protection involving, e.g. technology, legislation, until 1980s. Recently with the strong support from International Atomic Energy Agency (IAEA) and Vietnam government nuclear technology has been strongly and widely developed in different branches and radiation protection situation in Vietnam has been improved step by step. Strategy for Peaceful Utilization of Atomic Energy up to 2020 approved by the prime minister on January 3th, 2006 confirms that nuclear power plant will be put in operation by 2020. To ensure the implementation of the strategy, the first priority should be given to radiation protection and nuclear safety. This paper presents shortly some activities of radiation safety in Vietnam. The requirements for developing this field in Vietnam are also discussed. (author)

  13. Dam Construction in Lancang-Mekong River Basin Could Mitigate Future Flood Risk From Warming-Induced Intensified Rainfall: Dam Mitigate Flood Risk in Mekong

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei [Changjiang Institute of Survey, Planning, Design and Research, Wuhan China; Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing China; Lu, Hui [Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing China; Joint Center for Global Change Studies, Beijing China; Ruby Leung, L. [Pacific Northwest National Laboratory, Richland WA USA; Li, Hong-Yi [Department of Land Resources and Environmental Sciences and Institute on Ecosystems, Montana State University, Bozeman MT USA; Zhao, Jianshi [State Key Laboratory of Hydro-science and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing China; Tian, Fuqiang [State Key Laboratory of Hydro-science and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing China; Yang, Kun [Ministry of Education Key Laboratory for Earth System Modeling, Department of Earth System Science, Tsinghua University, Beijing China; Joint Center for Global Change Studies, Beijing China; Sothea, Khem [Mekong Institute of Cambodia, Phnom Penh Cambodia

    2017-10-25

    Water resources management, in particular flood control, in the Mekong River Basin (MRB) faces two key challenges in the 21st century: climate change and dam construction. A large scale distributed Geomorphology-Based Hydrological Model coupled with a simple reservoir regulation model (GBHM-MK-SOP) is used to investigate the relative effects of climate change and dam construction on the flood characteristics in the MRB. Results suggest an increase in both flood magnitude and frequency under climate change, which is more severe in the upstream basin and increases over time. However, dam construction and stream regulation reduce flood risk consistently throughout this century, with more obvious effects in the upstream basin where larger reservoirs will be located. The flood mitigation effect of dam regulation dominates over the flood intensification effect of climate change before 2060, but the latter emerges more prominently after 2060 and dominates the flood risk especially in the lower basin.

  14. Women of Niger Delta

    African Journals Online (AJOL)

    Religion Dept

    The Indispensability of Women in Conflict Resolution in the Niger Delta ... The situation leads to a shift in gender roles with a dramatic increase in the number of women .... organization is to work in partnership with the Nigerian Government and the .... that “women are the impartial arbitrators in family or clan disputes or.

  15. Conservative Delta Hedging

    Science.gov (United States)

    1997-09-01

    an exact method for converting such intervals into arbitrage based prices of financial derivatives or industrial or contractual options. We call this...procedure conservative delta hedging . As existing procedures are of an ad hoc nature, the proposed approach will permit an institution’s man agement a greater oversight of its exposure to risk.

  16. Changing fluxes of carbon and other solutes from the Mekong River.

    Science.gov (United States)

    Li, Siyue; Bush, Richard T

    2015-11-02

    Rivers are an important aquatic conduit that connects terrestrial sources of dissolved inorganic carbon (DIC) and other elements with oceanic reservoirs. The Mekong River, one of the world's largest rivers, is firstly examined to explore inter-annual fluxes of dissolved and particulate constituents during 1923-2011 and their associated natural or anthropogenic controls. Over this period, inter-annual fluxes of dissolved and particulate constituents decrease, while anthropogenic activities have doubled the relative abundance of SO4(2-), Cl(-) and Na(+). The estimated fluxes of solutes from the Mekong decrease as follows (Mt/y): TDS (40.4) > HCO3(-) (23.4) > Ca(2+) (6.4) > SO4(2-) (3.8) > Cl(-) (1.74)~Na(+) (1.7) ~ Si (1.67) > Mg(2+) (1.2) > K(+ 0.5). The runoff, land cover and lithological composition significantly contribute to dissolved and particulate yields globally. HCO3(-) and TDS yields are readily predicted by runoff and percent of carbonate, while TSS yield by runoff and population density. The Himalayan Rivers, including the Mekong, are a disproportionally high contributor to global riverine carbon and other solute budgets, and are of course underlined. The estimated global riverine HCO3(-) flux (Himalayan Rivers included) is 34,014 × 10(9) mol/y (0.41 Pg C/y), 3915 Mt/y for solute load, including HCO3(-), and 13,553 Mt/y for TSS. Thereby this study illustrates the importance of riverine solute delivery in global carbon cycling.

  17. Improved Lower Mekong River Basin Hydrological Decision Making Using NASA Satellite-based Earth Observation Systems

    Science.gov (United States)

    Bolten, J. D.; Mohammed, I. N.; Srinivasan, R.; Lakshmi, V.

    2017-12-01

    Better understanding of the hydrological cycle of the Lower Mekong River Basin (LMRB) and addressing the value-added information of using remote sensing data on the spatial variability of soil moisture over the Mekong Basin is the objective of this work. In this work, we present the development and assessment of the LMRB (drainage area of 495,000 km2) Soil and Water Assessment Tool (SWAT). The coupled model framework presented is part of SERVIR, a joint capacity building venture between NASA and the U.S. Agency for International Development, providing state-of-the-art, satellite-based earth monitoring, imaging and mapping data, geospatial information, predictive models, and science applications to improve environmental decision-making among multiple developing nations. The developed LMRB SWAT model enables the integration of satellite-based daily gridded precipitation, air temperature, digital elevation model, soil texture, and land cover and land use data to drive SWAT model simulations over the Lower Mekong River Basin. The LMRB SWAT model driven by remote sensing climate data was calibrated and verified with observed runoff data at the watershed outlet as well as at multiple sites along the main river course. Another LMRB SWAT model set driven by in-situ climate observations was also calibrated and verified to streamflow data. Simulated soil moisture estimates from the two models were then examined and compared to a downscaled Soil Moisture Active Passive Sensor (SMAP) 36 km radiometer products. Results from this work present a framework for improving SWAT performance by utilizing a downscaled SMAP soil moisture products used for model calibration and validation. Index Terms: 1622: Earth system modeling; 1631: Land/atmosphere interactions; 1800: Hydrology; 1836 Hydrological cycles and budgets; 1840 Hydrometeorology; 1855: Remote sensing; 1866: Soil moisture; 6334: Regional Planning

  18. Analysis of the Tonle Sap Flood Pulse Based on Remote Sensing: how much does Tonle Sap Lake Affect the Mekong River Flood?

    Science.gov (United States)

    Qu, W.; Hu, N.; Fu, J.; Lu, J.; Lu, H.; Lei, T.; Pang, Z.; Li, X.; Li, L.

    2018-04-01

    The economic value of the Tonle Sap Lake Floodplain to Cambodia is among the highest provided to a nation by a single ecosystem around the world. The flow of Mekong River is the primary factor affecting the Tonle Sap Lake Floodplain. The Tonle Sap Lake also plays a very important role in regulating the downstream flood of Mekong River. Hence, it is necessary to understand its temporal changes of lake surface and water storage and to analyse its relation with the flood processes of Mekong River. Monthly lake surface and water storage from July 2013 to May 2014 were first monitored based on remote sensing data. The relationship between water surface and accumulative water storage change was then established. In combination with hydrological modelling results of Mekong River Basin, the relation between the lake's water storage and the runoff of Mekong River was analysed. It is found that the water storage has a sharp increase from September to December and, after reaching its maximum in December, water storage quickly decreases with a 38.8 billion m3 of drop in only half month time from December to January, while it keeps rather stable at a lower level in other months. There is a two months' time lag between the maximum lake water storage and the Mekong River peak flood, which shows the lake's huge flood regulation role to downstream Mekong River. It shows that this remote sensing approach is feasible and reliable in quantitative monitoring of data scarce lakes.

  19. Rural Livelihoods, Climate Change and Micro-Level Adaptive Capacity in the Greater Mekong Subregion

    DEFF Research Database (Denmark)

    Jiao, Xi

    The Greater Mekong Subregion (GMS) is one of the fastest developing regions in the world, experiencing significant economic, environmental and social transformations. There is an increasing demand for policy relevant and decision support information at micro level. This PhD research contributes...... and Laos, two of the poorest countries in the GMS. Structured household surveys and participatory focus group discussions were the primary data collection methods. The findings provide new, additional and much needed quantitative information in the region, and several policy implications for rural...

  20. Mystery of the delta(980)

    International Nuclear Information System (INIS)

    Cahn, R.N.; Landshoff, P.V.

    1986-01-01

    The apparent conflict between the dominance of the decay delta->etaπ in D->deltaπ and its absence in iota->deltaπ is analyzed. Explicit models are presented in which the nearby Kanti K threshold plays an important role in resolving the conflict. (orig.)

  1. Neurology in the Vietnam War.

    Science.gov (United States)

    Gunderson, Carl H; Daroff, Robert B

    2016-01-01

    Between December 1965 and December 1971, the United States maintained armed forces in Vietnam never less than 180,000 men and women in support of the war. At one time, this commitment exceeded half a million soldiers, sailors, and airmen from both the United States and its allies. Such forces required an extensive medical presence, including 19 neurologists. All but two of the neurologists had been drafted for a 2-year tour of duty after deferment for residency training. They were assigned to Vietnam for one of those 2 years in two Army Medical Units and one Air Force facility providing neurological care for American and allied forces, as well as many civilians. Their practice included exposure to unfamiliar disorders including cerebral malaria, Japanese B encephalitis, sleep deprivation seizures, and toxic encephalitis caused by injection or inhalation of C-4 explosive. They and neurologists at facilities in the United States published studies on all of these entities both during and after the war. These publications spawned the Defense and Veterans Head Injury Study, which was conceived during the Korean War and continues today as the Defense and Veterans Head Injury Center. It initially focused on post-traumatic epilepsy and later on all effects of brain injury. The Agent Orange controversy arose after the war; during the war, it was not perceived as a threat by medical personnel. Although soldiers in previous wars had developed serious psychological impairments, post-traumatic stress disorder was formally recognized in the servicemen returning from Vietnam. © 2016 S. Karger AG, Basel.

  2. Vulnerability in north- central Vietnam

    DEFF Research Database (Denmark)

    Casse, Thorkil; Milhøj, Anders; Nguyen, Thao Phuong

    2015-01-01

    This article examines changes in livelihood strategies in response to flooding. It does so on the basis of a household survey which was undertaken in three provinces in north central Vietnam. All households in the survey were regularly affected by flooding, but only poor households experience a l...... the impact of flooding in the provinces. The article ends by looking at the vulnerability-resilience debate concluding that the poorer households could enter a vulnerability loop, unless new strategies to cope with natural hazards are suggested....

  3. Dams on Mekong tributaries as significant contributors of hydrological alterations to the Tonle Sap Floodplain in Cambodia

    Science.gov (United States)

    Arias, M. E.; Piman, T.; Lauri, H.; Cochrane, T. A.; Kummu, M.

    2014-12-01

    River tributaries have a key role in the biophysical functioning of the Mekong Basin. Of particular interest are the Sesan, Srepok, and Sekong (3S) rivers, which contribute nearly a quarter of the total Mekong discharge. Forty two dams are proposed in the 3S, and once completed they will exceed the active storage of China's large dam cascade in the Upper Mekong. Given their proximity to the Lower Mekong floodplains, the 3S dams could alter the flood-pulse hydrology driving the productivity of downstream ecosystems. Therefore, the main objective of this study was to quantify how hydropower development in the 3S, together with definite future (DF) plans for infrastructure development through the basin, would alter the hydrology of the Tonle Sap's Floodplain, the largest wetland in the Mekong and home to one of the most productive inland fisheries in the world. We coupled results from four numerical models representing the basin's surface hydrology, water resources development, and floodplain hydrodynamics. The scale of alterations caused by hydropower in the 3S was compared with the basin's DF scenario driven by the Upper Mekong dam cascade. The DF or the 3S development scenarios could independently increase Tonle Sap's 30-day minimum water levels by 30 ± 5 cm and decrease annual water level fall rates by 0.30 ± 0.05 cm day-1. When analyzed together (DF + 3S), these scenarios are likely to eliminate all baseline conditions (1986-2000) of extreme low water levels, a particularly important component of Tonle Sap's environmental flows. Given the ongoing trends and large economic incentives in the hydropower business in the region, there is a high possibility that most of the 3S hydropower potential will be exploited and that dams will be built even in locations where there is a high risk of ecological disruption. Hence, retrofitting current designs and operations to promote sustainable hydropower practices that optimize multiple river services - rather than just

  4. Applications of the SWOT Mission to Reservoirs in the Mekong River Basin

    Science.gov (United States)

    Bonnema, M.; Hossain, F.

    2017-12-01

    The forthcoming Surface Water and Ocean Topography (SWOT) mission has the potential to significantly improve our ability to observe artificial reservoirs globally from a remote sensing perspective. By providing simultaneous estimates of reservoir water surface extent and elevation with near global coverage, reservoir storage changes can be estimated. Knowing how reservoir storage changes over time is critical for understanding reservoir impacts on river systems. In data limited regions, remote sensing is often the only viable method of retrieving such information about reservoir operations. When SWOT launches in 2021, it will join an array of satellite sensors with long histories of reservoir observation and monitoring capabilities. There are many potential synergies in the complimentary use of future SWOT observations with observations from current satellite sensors. The work presented here explores the potential benefits of utilizing SWOT observations over 20 reservoirs in the Mekong River Basin. The SWOT hydrologic simulator, developed by NASA Jet Propulsion Laboratory, is used to generate realistic SWOT observations, which are then inserted into a previously established remote sensing modeling framework of the 20 Mekong Basin reservoirs. This framework currently combines data from Landsat missions, Jason radar altimeters, and the Shuttle Radar and Topography Mission (SRTM), to provide monthly estimates of reservoir storage change. The incorporation of SWOT derived reservoir surface area and elevation into the model is explored in an effort to improve both accuracy and temporal resolution of observed reservoir operations.

  5. Records of Wenchengia (Lamiaceae) from Vietnam

    Science.gov (United States)

    Phillipson, Peter B; Suddee, Somran

    2016-01-01

    Abstract Background The monotypic genus Wenchengia (Lamiaceae) has been thought to be endemic to Hainan, China. This paper reports on historic records of Wenchengia alternifolia collected from Vietnam. The recent recuration and modernisation of the Paris herbarium greatly facilitated this discovery. New information During preparatory work supporting the account for the Lamiaceae of the Flora of Thailand, three specimens of Wenchengia from central Vietnam were found in the Herbarium of the Musuem National d'Histoire Naturelle in Paris (P), and subsequently two duplicates were found in the Herbarium at Kew (K, abbreviations following Thiers 2016). The specimens were collected in and before 1927 and it is not known if the species is still extant in Vietnam. Searches for extant populations should focus in the Ba Na Hills or Bach Ma National Park, central Vietnam. PMID:27660535

  6. Intervention in Vietnam: President Eisenhower's Foreign Policy

    National Research Council Canada - National Science Library

    Slaton, James

    1995-01-01

    For a period of thirty years, from 1945 to 1975, the United States employed countless numbers of financial, material, and human resources toward Vietnam in an effort to shape and control that country's political destiny...

  7. Vietnam | IDRC - International Development Research Centre

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... of its success, local fishery associations secured fishing management rights in 2009, a first in Vietnam. ... We continue to support online education through regional research to improve the quality of distance education. Total IDRC Support ...

  8. Connecting Vietnam's isolated communities to improve healthcare ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2018-01-29

    Jan 29, 2018 ... Connecting Vietnam's isolated communities to improve healthcare ... of pregnancy and new motherhood improved their interactions with health workers. ... Return to main page: Overcoming eHealth challenges with social and ...

  9. Solar energy and rural development in Vietnam

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    Photovoltaic systems have already been present in Vietnam for numerous years. Since 1994 the projects intensified with the launch of the Energy-Solidarity-Vietnam program which has just been concluded in 1999. This paper deals with the different stages of this project: choice of photovoltaic power, the partners engagement, obstacles overcome and the help of the electricity for the economic development. (A.L.B.)

  10. Potential Economic Impacts of the Vietnam-Korea Free Trade Agreement on Vietnam

    Directory of Open Access Journals (Sweden)

    Thanh Hoan Phan

    2016-03-01

    Full Text Available This paper provides an assessment of the potential economic impacts of the Vietnam-Korea free trade agreement on Vietnam, by using general equilibrium modeling. The results show that Vietnam-Korea FTA will increase aggregate welfare for both countries in the long run. The most important gains accrue from better allocation of resources consequent to trade liberalization. All the sectoral differences and changes are consistent with the trade profiles of the two countries, and the long-run results are more pronounced than those of the short-run. In comparison with other ASEAN countries, the CGE analysis suggests that Vietnam's agriculture exports to Korea would especially rise in the long run. However, there will be strong competition in this sector among ASEAN members. Thus, an earlier conclusion of a comprehensive FTA with Korea is expected to be a good strategy for Vietnam, so as to avoid the direct competition with ASEAN members in the future.

  11. Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    1999-09-01

    As a Party to the United Nations Framework Convention on Climate Change (UNFCCC) Viet Nam will make its strong effort to implement the UNFCCC through effective activities in order to reduce GHG emissions as well as enhance carbon sinks in the country. The UNEP/GEF Project `Economics of GHG Limitation - Phase 1: Establishment of a Methodological Framework for Climate Change Mitigation Assessment` developed by the UNEP Collaborating Centre on Energy and Environment (UCCEE) in cooperation with Lawrence Berkeley Laboratory has been deployed in Viet Nam since 1996. The project deals with GHG mitigation analysis and options, focusing on the main issues: a) Associated macro-economics, b) Energy, c) Land use and forestry. For this study, a number of different data related to energy, industry, forestry and agriculture sectors as well as Viet Nam socio-economic development up to the year 2030, are collected. Besides, several models such as MEDEE-S, EFOM-ENV, COMAP are applied for development and assessment of GHG mitigation options in the next decades. The MEDEE-S and EFOM-ENV models are used as a tool for determining the cost-effective strategies to abate GHG emissions for energy sector while COMAP model is applied for forestry sector. (au) 39 refs.

  12. Analysis of air pollution over Hanoi, Vietnam using multi-satellite and MERRA reanalysis datasets.

    Directory of Open Access Journals (Sweden)

    Kristofer Lasko

    Full Text Available Air pollution is one of the major environmental concerns in Vietnam. In this study, we assess the current status of air pollution over Hanoi, Vietnam using multiple different satellite datasets and weather information, and assess the potential to capture rice residue burning emissions with satellite data in a cloud-covered region. We used a timeseries of Ozone Monitoring Instrument (OMI Ultraviolet Aerosol Index (UVAI satellite data to characterize absorbing aerosols related to biomass burning. We also tested a timeseries of 3-hourly MERRA-2 reanalysis Black Carbon (BC concentration data for 5 years from 2012-2016 and explored pollution trends over time. We then used MODIS active fires, and synoptic wind patterns to attribute variability in Hanoi pollution to different sources. Because Hanoi is within the Red River Delta where rice residue burning is prominent, we explored trends to see if the residue burning signal is evident in the UVAI or BC data. Further, as the region experiences monsoon-influenced rainfall patterns, we adjusted the BC data based on daily rainfall amounts. Results indicated forest biomass burning from Northwest Vietnam and Laos impacts Hanoi air quality during the peak UVAI months of March and April. Whereas, during local rice residue burning months of June and October, no increase in UVAI is observed, with slight BC increase in October only. During the peak BC months of December and January, wind patterns indicated pollutant transport from southern China megacity areas. Results also indicated severe pollution episodes during December 2013 and January 2014. We observed significantly higher BC concentrations during nighttime than daytime with peaks generally between 2130 and 0030 local time. Our results highlight the need for better air pollution monitoring systems to capture episodic pollution events and their surface-level impacts, such as rice residue burning in cloud-prone regions in general and Hanoi, Vietnam in

  13. Medical Hydrogeology of Asian Deltas: Status of Groundwater Toxicants and Nutrients, and Implications for Human Health

    Directory of Open Access Journals (Sweden)

    Mohammad A. Hoque

    2015-12-01

    Full Text Available Drinking water, a fluid primarily for human hydration, is also a source of mineral nutrients. Groundwater, a drinking water source for more than 70% of inhabitants living in Asian deltas, has received much attention because of its naturally occurring arsenic, but the linkage of arsenic toxicity with other water constituents has not been studied. In addition, although nutrients are generally provided by food, in under developed rural settings, where people subsist on low nutrient diets, drinking-water-nutrients may supply quantities critical to human health thereby preventing diseases. Here, we show, using augmented datasets from three Asian deltas (Bengal, Mekong, and Red River, that the chemical content of groundwater is so substantial that in some areas individuals obtain up to 50% or more of the recommended daily intake (RDI of some nutrients (e.g., calcium, magnesium, iron from just two litres of drinking water. We also show some indications of a spatial association of groundwater nutrients and health outcome using demographic health data from Bangladesh. We therefore suggest that an understanding of the association of non-communicable disease and poor nutrition cannot be developed, particularly in areas with high levels of dissolved solids in water sources, without considering the contribution of drinking water to nutrient and mineral supply.

  14. Medical Hydrogeology of Asian Deltas: Status of Groundwater Toxicants and Nutrients, and Implications for Human Health.

    Science.gov (United States)

    Hoque, Mohammad A; Butler, Adrian P

    2015-12-26

    Drinking water, a fluid primarily for human hydration, is also a source of mineral nutrients. Groundwater, a drinking water source for more than 70% of inhabitants living in Asian deltas, has received much attention because of its naturally occurring arsenic, but the linkage of arsenic toxicity with other water constituents has not been studied. In addition, although nutrients are generally provided by food, in under developed rural settings, where people subsist on low nutrient diets, drinking-water-nutrients may supply quantities critical to human health thereby preventing diseases. Here, we show, using augmented datasets from three Asian deltas (Bengal, Mekong, and Red River), that the chemical content of groundwater is so substantial that in some areas individuals obtain up to 50% or more of the recommended daily intake (RDI) of some nutrients (e.g., calcium, magnesium, iron) from just two litres of drinking water. We also show some indications of a spatial association of groundwater nutrients and health outcome using demographic health data from Bangladesh. We therefore suggest that an understanding of the association of non-communicable disease and poor nutrition cannot be developed, particularly in areas with high levels of dissolved solids in water sources, without considering the contribution of drinking water to nutrient and mineral supply.

  15. Thermostatted delta f

    International Nuclear Information System (INIS)

    Krommes, J.A.

    2000-01-01

    The delta f simulation method is revisited. Statistical coarse-graining is used to rigorously derive the equation for the fluctuation delta f in the particle distribution. It is argued that completely collisionless simulation is incompatible with the achievement of true statistically steady states with nonzero turbulent fluxes because the variance of the particle weights w grows with time. To ensure such steady states, it is shown that for dynamically collisionless situations a generalized thermostat or W-stat may be used in lieu of a full collision operator to absorb the flow of entropy to unresolved fine scales in velocity space. The simplest W-stat can be implemented as a self-consistently determined, time-dependent damping applied to w. A precise kinematic analogy to thermostatted nonequilibrium molecular dynamics (NEMD) is pointed out, and the justification of W-stats for simulations of turbulence is discussed. An extrapolation procedure is proposed such that the long-time, steady-state, collisionless flux can be deduced from several short W-statted runs with large effective collisionality, and a numerical demonstration is given

  16. People of the Delta

    Energy Technology Data Exchange (ETDEWEB)

    Gregoire, L.

    2007-09-15

    The potential impacts of both global warming and the $16 billion Mackenzie pipeline project on communities in the Mackenzie Delta were discussed. A consortium of oil and gas developers is now planning to exploit the natural gas reserves located near the mouth of the Delta, whose largest town is Inuvik. The project is expected to place a significant burden on the resources and infrastructure of the town, which currently has a population of 6000. The community, comprised of a diverse international population and an Inuit majority, is largely in favour of the pipeline project. The Inuvialuit people have invested a significant amount of time to ensure that the project, which was stalled due to land claims in 1977, benefits their communities. Public hearings are now being held to consider the potential environmental and socio-economic impacts of the project. Separate hearings are also being held to consider the project's design. The pipeline project includes 3 natural gas production facilities, a gas-processing facility, a pipeline gathering system, a 480 km natural gas liquids pipeline to the Northwest Territories, and a 1220 km natural gas pipeline to northern Alberta. The pipeline will be buried to minimize environmental impacts. The project is expected to create 8200 jobs at the height of its construction. However, communities located near the site of the natural gas reserves, such as the town of Tuktoyaktuk are now threatened by soil erosion that has been attributed to global warming. 21 figs.

  17. Phenotypic expressions of CCR5-Delta 32/Delta 32 homozygosity

    NARCIS (Netherlands)

    Nguyen, GT; Carrington, M; Beeler, JA; Dean, M; Aledort, LM; Blatt, PM; Cohen, AR; DiMichele, D; Eyster, ME; Kessler, CM; Konkle, B; Leissinger, C; Luban, N; O'Brien, SJ; Goedert, JJ; O'Brien, TR

    1999-01-01

    Objective: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-Delta 32/Delta 32 homozygous genotype has phenotypic expressions other than those related to HIV-1. Design: Study subjects were white homosexual men or men with hemophilia

  18. Peat compaction in deltas : implications for Holocene delta evolution

    NARCIS (Netherlands)

    van Asselen, S.

    2010-01-01

    Many deltas contain substantial amounts of peat, which is the most compressible soil type. Therefore, peat compaction potentially leads to high amounts of subsidence in deltas. The main objective of this research was to quantify subsidence due to peat compaction in Holocene fluvial-deltaic settings

  19. Women at war: The crucible of Vietnam.

    Science.gov (United States)

    Pless Kaiser, Anica; Kabat, Daniel H; Spiro, Avron; Davison, Eve H; Stellman, Jeanne Mager

    2017-12-01

    Relatively little has been written about the military women who served in Vietnam, and there is virtually no literature on deployed civilian women (non-military). We examined the experiences of 1285 American women, military and civilian, who served in Vietnam during the war and responded to a mail survey conducted approximately 25 years later in which they were asked to report and reflect upon their experiences and social and health histories. We compare civilian women, primarily American Red Cross workers, to military women stratified by length of service, describe their demographic characteristics and warzone experiences (including working conditions, exposure to casualties and sexual harassment), and their homecoming following Vietnam. We assess current health and well-being and also compare the sample to age- and temporally-comparable women in the General Social Survey (GSS), with which our survey shared some measures. Short-term (Vietnam experience as "highly stressful" than were career (>20 years; 12%) and civilian women (13%). Additional differences regarding warzone experiences, homecoming support, and health outcomes were found among groups. All military and civilian women who served in Vietnam were less likely to have married or have had children than women from the general population, χ 2 (8) = 643.72, p Vietnam reported better health than women in the other groups. Regression analyses indicated that long-term physical health was mainly influenced by demographic characteristics, and that mental health and PTSD symptoms were influenced by warzone and homecoming experiences. Overall, this paper provides insight into the experiences of the understudied women who served in Vietnam, and sheds light on subgroup differences within the sample.

  20. Node and Regime: Interdisciplinary Analysis of Water-Energy-Food Nexus in the Mekong Region

    Directory of Open Access Journals (Sweden)

    Tira Foran

    2015-02-01

    Full Text Available Understanding complex phenomena such as the water-energy-food nexus (resource nexus requires a more holistic, interdisciplinary inquiry. Spurred by a sense of imbalance in approaches to the nexus dominated by integrated assessment/complex systems methodologies, I re-examine the findings and recommendations of a major 'nexus' research-for-development project in the Mekong region. The concept of 'regime of provisioning', a synthesis of social science concepts related to meso-level social order, allows essential political economy and discursive elements of the resource nexus to be analysed. I show that socio-political regimes constrain societal investment in three 'nodes' of the nexus previously identified as critical to manage sustainably: energy efficiency, wild-capture fisheries, and diversified smallholder agriculture. I discuss implications for the 'nexus' as a new policy agenda and offer three propositions for ongoing inquiry and inclusive practice.

  1. Rethinking Conceptions of Borders in the Greater Mekong Subregion: An Interview With Chayan Vaddhanabhuti (RCSD

    Directory of Open Access Journals (Sweden)

    Napakadol Kittisenee

    2011-01-01

    Full Text Available Dr. Chayan Vaddhanabhuti is Director of the Regional Centre for Social Science and Sustainable Development (RCSD, Thailand. The RCSD was established in 1998 at the Faculty of Social Sciences, Chiang Mai University, in response to the need for integration of social science and natural science knowledge in order to gain a better understanding of sustainable development in upper Mainland South-East Asia. Chayan Vaddhanabhuti has long been dedicated to the fi eld of social sciences, development issues, and engaged himself extensively with ethnic groups both within Thailand and beyond. In this interview he introduces the work of RSCD and discusses the changing perceptions of the concept of ‘border’ in the context of Thailand and the Greater Mekong Subregion.

  2. Simulating hydrological processes in a sub-basin of the Mekong using GBHM and RS data

    Directory of Open Access Journals (Sweden)

    W. Wang

    2015-05-01

    Full Text Available This paper presents simulations of daily hydrological process of the Mun River, the largest tributary of the Mekong, with a geomorphology-based hydrological model (GBHM driven by two forcing sets: traditional station data and grid data derived from remote sensing and GLDAS products. Driven by the station data, the Mun-GBHM model is successfully calibrated against the discharge observed in 1991, but the model accuracy decreases with the increase of simulation time during the validation period of 1992–1999. Driven by the TRMM rainfall and other meteorological data from GLDAS, using the same parameters as above, the model performs reliably at both the monthly and daily scale. Moreover, when the model is calibrated with one year of gridded data, its performance can be further improved. Our results demonstrate that TRMM and GLDAS are able to drive the GBHM so providing reliable hydrologic predictions in such data-poor or ungauged basins.

  3. Improving Smallholder Farmer Biosecurity in the Mekong Region Through Change Management.

    Science.gov (United States)

    Young, J R; Evans-Kocinski, S; Bush, R D; Windsor, P A

    2015-10-01

    Transboundary animal diseases including foot-and-mouth disease and haemorrhagic septicaemia remain a major constraint for improving smallholder large ruminant productivity in the Mekong region, producing negative impacts on rural livelihoods and compromising efforts to reduce poverty and food insecurity. The traditional husbandry practices of smallholders largely exclude preventive health measures, increasing risks of disease transmission. Although significant efforts have been made to understand the social aspects of change development in agricultural production, attention to improving the adoption of biosecurity has been limited. This study reviews smallholder biosecurity risk factors identified in the peer-reviewed literature and from field research observations conducted in Cambodia and Laos during 2006-2013, considering these in the context of a change management perspective aimed at improving adoption of biosecurity measures. Motivation for change, resistance to change, knowledge management, cultural dimensions, systems theory and leadership are discussed. Due to geographical, physical and resource variability, the implementation of biosecurity interventions suitable for smallholders is not a 'one size fits all'. Smallholders should be educated in biosecurity principles and empowered to make personal decisions rather than adopt prescribed pre-defined interventions. Biosecurity interventions should be aligned with smallholder farmer motivations, preferably offering clear short-term risk management benefits that elicit interest from smallholders. Linking biosecurity and disease control with improved livestock productivity provides opportunities for sustainable improvements in livelihoods. Participatory research and extension that improves farmer knowledge and practices offers a pathway to elicit sustainable broad-scale social change. However, examples of successes need to be communicated both at the 'evidence-based level' to influence regional policy

  4. Infilling and flooding of the Mekong River incised valley during deglacial sea-level rise

    Science.gov (United States)

    Tjallingii, Rik; Stattegger, Karl; Wetzel, Andreas; Van Phach, Phung

    2010-06-01

    The abrupt transition from fluvial to marine deposition of incised-valley-fill sediments retrieved from the southeast Vietnamese shelf, accurately records the postglacial transgression after 14 ka before present (BP). Valley-filling sediments consist of fluvial mud, whereas sedimentation after the transgression is characterized by shallow-marine carbonate sands. This change in sediment composition is accurately marked in high-resolution X-ray fluorescence (XRF) core scanning records. Rapid aggradation of fluvial sediments at the river mouth nearly completely filled the Mekong incised valley prior to flooding. However, accumulation rates strongly reduced in the valley after the river-mouth system flooded and stepped back. This also affected the sediment supply to deeper parts of the southeast Vietnamese shelf. Comparison of the Mekong valley-filling with the East Asian sea-level history of sub- and inter-tidal sediment records shows that the transgressive surface preserved in the incised-valley-fill records is a robust sea-level indicator. The valley was nearly completely filled with fluvial sediments between 13.0 and 9.5 ka BP when sea-level rose rather constantly with approximately 10 mm/yr, as indicated by the East Asian sea-level record. At shallower parts of the shelf, significant sediment reworking and the establishment of estuarine conditions at the final stage of infilling complicates accurate dating of the transgressive surface. Nevertheless, incised-valley-fill records and land-based drill sites indicate a vast and rapid flooding of the shelf from the location of the modern Vietnamese coastline to the Cambodian lowlands between 9.5 ka and 8.5 ka BP. Fast flooding of this part of the shelf is related with the low shelf gradient and a strong acceleration of the East Asian sea-level rise from 34 to 9 meter below modern sea level (mbsl) corresponding to the sea-level jump of melt water pulse (MWP) 1C.

  5. River reach classification for the Greater Mekong Region at high spatial resolution

    Science.gov (United States)

    Ouellet Dallaire, C.; Lehner, B.

    2014-12-01

    River classifications have been used in river health and ecological assessments as coarse proxies to represent aquatic biodiversity when comprehensive biological and/or species data is unavailable. Currently there are no river classifications or biological data available in a consistent format for the extent of the Greater Mekong Region (GMR; including the Irrawaddy, the Salween, the Chao Praya, the Mekong and the Red River basins). The current project proposes a new river habitat classification for the region, facilitated by the HydroSHEDS (HYDROlogical SHuttle Elevation Derivatives at multiple Scales) database at 500m pixel resolution. The classification project is based on the Global River Classification framework relying on the creation of multiple sub-classifications based on different disciplines. The resulting classes from the sub-classification are later combined into final classes to create a holistic river reach classification. For the GMR, a final habitat classification was created based on three sub-classifications: a hydrological sub-classification based only on discharge indices (river size and flow variability); a physio-climatic sub-classification based on large scale indices of climate and elevation (biomes, ecoregions and elevation); and a geomorphological sub-classification based on local morphology (presence of floodplains, reach gradient and sand transport). Key variables and thresholds were identified in collaboration with local experts to ensure that regional knowledge was included. The final classification is composed 54 unique final classes based on 3 sub-classifications with less than 15 classes each. The resulting classifications are driven by abiotic variables and do not include biological data, but they represent a state-of-the art product based on best available data (mostly global data). The most common river habitat type is the "dry broadleaf, low gradient, very small river". These classifications could be applied in a wide range of

  6. Visions, beliefs, and transformation: exploring cross-sector and transboundary dynamics in the wider Mekong region

    Directory of Open Access Journals (Sweden)

    Alex Smajgl

    2015-06-01

    Full Text Available Policy and investment decisions in highly connected, developing regions can have implications that extend beyond their initial objectives of national development and poverty reduction. Local level decisions that aim to promote trajectories toward desirable futures are often transformative, unexpectedly altering factors that are determined at higher regional levels. The converse also applies. The ability to realize desirable local futures diminishes if decision-making processes are not coordinated with other influential governance and decision levels. Providing effective support across multiple levels of decision making in a connected, transformative environment requires (a identification and articulation of desired outcomes at the relevant levels of decision making, (b improved understanding of complex cross-scale interactions that link to potentially transforming decisions, and (c learning among decision makers and decision influencers. Research implemented through multiple participatory modalities can facilitate such relevant system learning to contribute to sustainable adaptation pathways. We test application of a systematic policy engagement framework, the Challenge and Reconstruct Learning or ChaRL framework, on a set of interdependent development decisions in the Mekong region. The analysis presented here is focused on the implementations of the ChaRL process in the Nam Ngum River Basin, Lao People's Democratic Republic and the Tonle Sap Lake and environs, Cambodia to exemplify what cross-scale and cross-sectoral insights were generated to inform decision-making processes in the wider Mekong region. The participatory process described aligns the facilitated development of scenarios articulating shared future visions at local and regional levels with agent-based simulations and facilitates learning by contrasting desired outcomes with likely, potentially maladaptive outcomes.

  7. Job Prospects in the Mekong | CRDI - Centre de recherches pour le ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Agent(e) responsable du CRDI. Edgard Rodriguez. Financement total. CAD$ 1,029,600. Pays. Cambodge, Chine, Laos, Birmanie, Thaïlande, Vietnam, Indonésie, Malaisie, Philippines, Brunéi, Singapour. Chargé(e) de projet. Chhem Rethy. Institution. The Cambodia Development Resource Institute. Pays d' institution.

  8. Mida pakub Delta? / Teele Kurm

    Index Scriptorium Estoniae

    Kurm, Teele

    2011-01-01

    Politsei- ja Piirivalveamet võtab kasutusele ühise Siseministeeriumi infotehnoloogia- ja arenduskeskuse ning Webmedia AS koostööna loodud dokumendihaldussüsteemi Delta. Kust sai Delta oma nime? Projekti "Dokumendihaldussüsteemi juurutamine Siseministeeriumi haldusalas" eesmärgid

  9. Entry modes of European firms in Vietnam

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    Daniel Simonet

    2012-09-01

    Full Text Available Purpose: The purpose of the paper is to explore the entry modes of EU firms setting up operations in Vietnam. Design/methodology/approach: we use a case study approach on Haymarket, Cadbury, Creative Education, Fairchild, Aventis and Artemisinin and Farming International using interviews from managerial professionals in Vietnam. Findings: Despite the fact that Vietnam has been opening up for more than 20 years, licensing is the preferred entry mode because of the risks involved in venturing with local firms; that preference signals a low level commitment and a high perception of risk and state interference. In line with Vietnam transition to state - rather than private market - capitalism, a foreign company opting for a joint-venture will do so with a state-owned rather than privately-owned company. The choice of a subsidiary can be explained by the lack of trust in partners and institutions, not by improvement in the socio-political environment. Limitations: In determining the entry mode strategy, the paper focuses on the Uppsala school’s “psychic distance” (e.g. cultural distance, lack of trust rather than on firm-specific advantages (Rugman, 1980; 2006. Key-words: international entry mode; emerging markets; subsidiary; joint-venture; India; Vietnam

  10. New records of marine algae in Vietnam

    Science.gov (United States)

    Le Hau, Nhu; Ly, Bui Minh; Van Huynh, Tran; Trung, Vo Thanh

    2015-06-01

    In May, 2013, a scientific expedition was organized by the Vietnam Academy of Science and Technology (VAST) and the Far Eastern Branch of the Russian Academy of Sciences (FEBRAS) through the frame of the VAST-FEBRAS International Collaboration Program. The expedition went along the coast of Vietnam from Quang Ninh to Kien Giang. The objective was to collect natural resources to investigate the biological and biochemical diversity of the territorial waters of Vietnam. Among the collected algae, six taxa are new records for the Vietnam algal flora. They are the red algae Titanophora pikeana (Dickie) Feldmann from Cu Lao Xanh Island, Laurencia natalensis Kylin from Tho Chu Island, Coelothrix irregularis (Harvey) Børgesen from Con Dao Island, the green algae Caulerpa oligophylla Montagne, Caulerpa andamanensis (W.R. Taylor) Draisma, Prudhomme et Sauvage from Phu Quy Island, and Caulerpa falcifolia Harvey & Bailey from Ly Son Island. The seaweed flora of Vietnam now counts 833 marine algal taxa, including 415 Rhodophyta, 147 Phaeophyceae, 183 Chlorophyta, and 88 Cyanobacteria.

  11. Vietnam military service history and prostate cancer

    Directory of Open Access Journals (Sweden)

    Fritschi Lin

    2006-03-01

    Full Text Available Abstract Background Three decades after US and Australian forces withdrew from Vietnam, there has been much public interest in the health consequences of service in Vietnam. One controversial question is whether the risk of prostate cancer amongst Vietnam veterans is increased. This paper examines relationships between military history, family history and risk of prostate cancer in a population-based case control study. Methods Cases were selected from the Cancer Registry of Western Australia as incident cases of histologically-confirmed prostate cancer, and controls were age-matched and selected from the Western Australian electoral roll. Study participants were asked to report any military service history and details about that service. Results Between January 2001 and September 2002, 606 cases and 471 controls aged between 40–75 years were recruited. An increased prostate cancer risk was observed in men reporting they were deployed in Vietnam although this was not statistically significant (OR = 2.12; 95% CI 0.88–5.06. An increased risk was also observed in men reporting prostate cancer in fathers (OR = 1.90; 95% CI 1.20–3.00 or brothers (OR = 2.05; 95% CI 1.20–3.50 diagnosed with prostate cancer. Conclusion These findings support a positive association between prostate cancer and military service history in the Vietnam war and a first degree relative family history of prostate cancer.

  12. Delta isobars in neutron stars

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    Pagliara Giuseppe

    2015-01-01

    Full Text Available The appearance of delta isobars in beta-stable matter is regulated by the behavior of the symmetry energy at densities larger than saturation density. We show that by taking into account recent constraints on the density derivative of the symmetry energy and the theoretical and experimental results on the excitations of delta isobars in nuclei, delta isobars are necessary ingredients for the equations of state used for studying neutron stars. We analyze the effect of the appearance of deltas on the structure of neutron stars: as in the case of hyperons, matter containing delta is too soft for allowing the existence of 2M⊙ neutron stars. Quark stars on the other hand, could reach very massive configurations and they could form from a process of conversion of hadronic stars in which an initial seed of strangeness appears through hyperons.

  13. Two new species of shovel-jaw carp Onychostoma (Teleostei: Cyprinidae) from southern Vietnam.

    Science.gov (United States)

    Hoang, Huy Duc; Pham, Hung Manh; Tran, Ngan Trong

    2015-05-22

    Two new species of large shovel-jaw carps in the genus Onychostoma are described from the upper Krong No and middle Dong Nai drainages of the Langbiang Plateau in southern Vietnam. These new species are known from streams in montane mixed pine and evergreen forests between 140 and 1112 m. Their populations are isolated in the headwaters of the upper Sre Pok River of the Mekong basin and in the middle of the Dong Nai basin. Both species are differentiated from their congeners by a combination of the following characters: transverse mouth opening width greater than head width, 14-17 predorsal scales, caudal-peduncle length 3.9-4.2 times in SL, no barbels in adults and juveniles, a strong serrated last simple ray of the dorsal fin, and small eye diameter (20.3-21.5% HL). Onychostoma krongnoensis sp. nov. is differentiated from Onychostoma dongnaiensis sp. nov. by body depth (4.0 vs. 3.2 times in SL), predorsal scale number (14-17 vs. 14-15), dorsal-fin length (4.5 vs. 4.2 times in SL), caudal-peduncle length (3.9 vs. 4.2 times in SL), colour in life (dark vs. bright), and by mitochondrial DNA (0.2% sequence divergence). Molecular evidence indicates that both species are members of Onychostoma and are distinct from all congeners sampled (uncorrected sequence divergences at the 16S rRNA gene of >2.0% for all Onychostoma for which homologous 16S rRNA sequences are available).

  14. River levels derived with CryoSat-2 SAR data classification - A case study in the Mekong River Basin

    DEFF Research Database (Denmark)

    Boergens, Eva; Nielsen, Karina; Andersen, Ole Baltazar

    2017-01-01

    becomes smaller. Therefore, we developed a classification approach to divide the observations into water and land returns based solely on the data. The classification is done with an unsupervised classification algorithm, and it is based on features derived from the SAR and range-integrated power (RIP......) waveforms. After the classification, classes representing water and land are identified. Better results are obtained when the Mekong River Basin is divided into different geographical regions: upstream, middle stream, and downstream. The measurements classified as water are used in a next step to estimate...... water levels for each crossing over a river in the Mekong River network. The resulting water levels are validated and compared to gauge data, Envisat data, and CryoSat-2 water levels derived with a land-water mask. The CryoSat-2 water levels derived with the classification lead to more valid...

  15. The Lessons of the Vietnam War: Unit 13. Teacher's Manual: Strategies and Resources for Teaching the Vietnam War.

    Science.gov (United States)

    Center for Social Studies Education, Pittsburgh, PA.

    This teacher's manual is designed to accompany the curriculum "The Lessons of the Vietnam War." For each of 12 units of the curriculum, this manual suggests projects for student research and classroom activities. The 12 units are entitled: (1) Introduction to Vietnam: land, history and culture; (2) America at war in Vietnam: decisions and…

  16. DELTA 3D PRINTER

    Directory of Open Access Journals (Sweden)

    ȘOVĂILĂ Florin

    2016-07-01

    Full Text Available 3D printing is a very used process in industry, the generic name being “rapid prototyping”. The essential advantage of a 3D printer is that it allows the designers to produce a prototype in a very short time, which is tested and quickly remodeled, considerably reducing the required time to get from the prototype phase to the final product. At the same time, through this technique we can achieve components with very precise forms, complex pieces that, through classical methods, could have been accomplished only in a large amount of time. In this paper, there are presented the stages of a 3D model execution, also the physical achievement after of a Delta 3D printer after the model.

  17. A Review of the Integrated Effects of Changing Climate, Land Use, and Dams on Mekong River Hydrology

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    Yadu Pokhrel

    2018-03-01

    Full Text Available The ongoing and proposed construction of large-scale hydropower dams in the Mekong river basin is a subject of intense debate and growing international concern due to the unprecedented and potentially irreversible impacts these dams are likely to have on the hydrological, agricultural, and ecological systems across the basin. Studies have shown that some of the dams built in the tributaries and the main stem of the upper Mekong have already caused basin-wide impacts by altering the magnitude and seasonality of flows, blocking sediment transport, affecting fisheries and livelihoods of downstream inhabitants, and changing the flood pulse to the Tonle Sap Lake. There are hundreds of additional dams planned for the near future that would result in further changes, potentially causing permanent damage to the highly productive agricultural systems and fisheries, as well as the riverine and floodplain ecosystems. Several studies have examined the potential impacts of existing and planned dams but the integrated effects of the dams when combined with the adverse hydrologic consequences of climate change remain largely unknown. Here, we provide a detailed review of the existing literature on the changes in climate, land use, and dam construction and the resulting impacts on hydrological, agricultural, and ecological systems across the Mekong. The review provides a basis to better understand the effects of climate change and accelerating human water management activities on the coupled hydrological-agricultural-ecological systems, and identifies existing challenges to study the region’s Water, Energy, and Food (WEF nexus with emphasis on the influence of future dams and projected climate change. In the last section, we synthesize the results and highlight the urgent need to develop integrated models to holistically study the coupled natural-human systems across the basin that account for the impacts of climate change and water infrastructure development

  18. Decoding the drivers of bank erosion on the Mekong river: The roles of the Asian monsoon, tropical storms, and snowmelt.

    Science.gov (United States)

    Darby, Stephen E; Leyland, Julian; Kummu, Matti; Räsänen, Timo A; Lauri, Hannu

    2013-04-01

    We evaluate links between climate and simulated river bank erosion for one of the world's largest rivers, the Mekong. We employ a process-based model to reconstruct multidecadal time series of bank erosion at study sites within the Mekong's two main hydrological response zones, defining a new parameter, accumulated excess runoff (AER), pertinent to bank erosion. We employ a hydrological model to isolate how snowmelt, tropical storms and monsoon precipitation each contribute to AER and thus modeled bank erosion. Our results show that melt (23.9% at the upstream study site, declining to 11.1% downstream) and tropical cyclones (17.5% and 26.4% at the upstream and downstream sites, respectively) both force significant fractions of bank erosion on the Mekong. We also show (i) small, but significant, declines in AER and hence assumed bank erosion during the 20th century, and; (ii) that significant correlations exist between AER and the Indian Ocean Dipole (IOD) and El Niño Southern Oscillation (ENSO). Of these modes of climate variability, we find that IOD events exert a greater control on simulated bank erosion than ENSO events; but the influences of both ENSO and IOD when averaged over several decades are found to be relatively weak. However, importantly, relationships between ENSO, IOD, and AER and hence inferred river bank erosion are not time invariant. Specifically, we show that there is an intense and prolonged epoch of strong coherence between ENSO and AER from the early 1980s to present, such that in recent decades derived Mekong River bank erosion has been more strongly affected by ENSO.

  19. Application of Regional Drought and Crop Yield Information System to enhance drought monitoring and forecasting in Lower Mekong region

    Science.gov (United States)

    Jayasinghe, S.; Dutta, R.; Basnayake, S. B.; Granger, S. L.; Andreadis, K. M.; Das, N.; Markert, K. N.; Cutter, P. G.; Towashiraporn, P.; Anderson, E.

    2017-12-01

    The Lower Mekong Region has been experiencing frequent and prolonged droughts resulting in severe damage to agricultural production leading to food insecurity and impacts on livelihoods of the farming communities. Climate variability further complicates the situation by making drought harder to forecast. The Regional Drought and Crop Yield Information System (RDCYIS), developed by SERVIR-Mekong, helps decision makers to take effective measures through monitoring, analyzing and forecasting of drought conditions and providing early warnings to farmers to make adjustments to cropping calendars. The RDCYIS is built on regionally calibrated Regional Hydrologic Extreme Assessment System (RHEAS) framework that integrates the Variable Infiltration Capacity (VIC) and Decision Support System for Agro-technology Transfer (DSSAT) models, allowing both nowcast and forecast of drought. The RHEAS allows ingestion of numerus freely available earth observation and ground observation data to generate and customize drought related indices, variables and crop yield information for better decision making. The Lower Mekong region has experienced severe drought in 2016 encompassing the region's worst drought in 90 years. This paper presents the simulation of the 2016 drought event using RDCYIS based on its hindcast and forecast capabilities. The regionally calibrated RDCYIS can help capture salient features of drought through a variety of drought indices, soil variables, energy balance variables and water balance variables. The RDCYIS is capable of assimilating soil moisture data from different satellite products and perform ensemble runs to further reduce the uncertainty of it outputs. The calibrated results have correlation coefficient around 0.73 and NSE between 0.4-0.5. Based on the acceptable results of the retrospective runs, the system has the potential to generate reliable drought monitoring and forecasting information to improve decision-makings at operational, technological and

  20. The Environmental Pollution In Vietnam Source Impact And Remedies

    OpenAIRE

    Tuan Anh Hoang; Nam Xuan Chu; Trung Van Tran

    2017-01-01

    Currently the environmental problems is one of the urgent problems for all countries in the world. Vietnam is among of 10 countries with the most polluted air in the world the health of people is affected by the non-guaranteed air quality in Vietnam. According to the EPI in 2015 Vietnam ranked 79 in the total of 132 countries in the overall environmental assessment. However the air pollution index Vietnam ranked 123. On the burden of disease due to environment Vietnam ranked 77. Therefore the...

  1. Potential Effects of Dams on Migratory Fish in the Mekong River: Lessons from Salmon in the Fraser and Columbia Rivers

    Science.gov (United States)

    Ferguson, John W.; Healey, Michael; Dugan, Patrick; Barlow, Chris

    2011-01-01

    We compared the effects of water resource development on migratory fish in two North American rivers using a descriptive approach based on four high-level indicators: (1) trends in abundance of Pacific salmon, (2) reliance on artificial production to maintain fisheries, (3) proportion of adult salmon that are wild- versus hatchery-origin, and (4) number of salmon populations needing federal protection to avoid extinction. The two rivers had similar biological and physical features but radically different levels of water resource development: the Fraser River has few dams and all are located in tributaries, whereas the Columbia River has more than 130 large mainstem and tributary dams. Not surprisingly, we found substantial effects of development on salmon in the Columbia River. We related the results to potential effects on migratory fish in the Mekong River where nearly 200 mainstem and tributary dams are installed, under construction, or planned and could have profound effects on its 135 migratory fish species. Impacts will vary with dam location due to differential fish production within the basin, with overall effects likely being greatest from 11 proposed mainstem dams. Minimizing impacts will require decades to design specialized fish passage facilities, dam operations, and artificial production, and is complicated by the Mekong's high diversity and productivity. Prompt action is needed by governments and fisheries managers to plan Mekong water resource development wisely to prevent impacts to the world's most productive inland fisheries, and food security and employment opportunities for millions of people in the region.

  2. Socio-economic Impact Analysis for Near Real-Time Flood Detection in the Lower Mekong River Basin

    Science.gov (United States)

    Oddo, P.; Ahamed, A.; Bolten, J. D.

    2017-12-01

    Flood events pose a severe threat to communities in the Lower Mekong River Basin. The combination of population growth, urbanization, and economic development exacerbate the impacts of these flood events. Flood damage assessments are frequently used to quantify the economic losses in the wake of storms. These assessments are critical for understanding the effects of flooding on the local population, and for informing decision-makers about future risks. Remote sensing systems provide a valuable tool for monitoring flood conditions and assessing their severity more rapidly than traditional post-event evaluations. The frequency and severity of extreme flood events are projected to increase, further illustrating the need for improved flood monitoring and impact analysis. In this study we implement a socio-economic damage model into a decision support tool with near real-time flood detection capabilities (NASA's Project Mekong). Surface water extent for current and historical floods is found using multispectral Moderate-resolution Imaging Spectroradiometer (MODIS) 250-meter imagery and the spectral Normalized Difference Vegetation Index (NDVI) signatures of permanent water bodies (MOD44W). Direct and indirect damages to populations, infrastructure, and agriculture are assessed using the 2011 Southeast Asian flood as a case study. Improved land cover and flood depth assessments result in a more refined understanding of losses throughout the Mekong River Basin. Results suggest that rapid initial estimates of flood impacts can provide valuable information to governments, international agencies, and disaster responders in the wake of extreme flood events.

  3. The Independence of Vietnam Regulatory Body

    International Nuclear Information System (INIS)

    Nguyen, Hoang Anh; Choi, Kwang Sik

    2011-01-01

    In the field of peaceful purposes, the activity of nuclear agencies is often divided into 2 systems: the nuclear application system and the safety system. Depending on the magnitude of atomic energy application development, the responsibility of the safety system was assigned to a few agencies in each country. In Vietnam, the nuclear safety responsibility is assigned primarily to the radiation and nuclear safety agency. However, the provisions of the normative system of law prevailing in other sectors such as investment, construction, electricity or environmental protection, many agencies are responsible for ensuring safety in each sector, leading to a conflict of interest among those agencies. This is the weakness in the management system of Vietnam compared to other countries with nuclear power development. The purpose of this paper is to analyze the state of Vietnam's legal framework in nuclear safety regulation and its dependence of regulatory body aspects and promoting the way to overcome it

  4. Universal service in Vietnam: An institutional approach

    DEFF Research Database (Denmark)

    Do Manh, Thai; Falch, Morten

    2018-01-01

    Applying institutional theory to look at the Program 74 (a universal service policy) in Vietnam, this paper concludes that the Vietnamese universal service policy was strongly affected by formal institutional factors (the international agreements and the directives of the Communist Party of Vietnam...... - CPV), in which the international agreements played a leading role and the CPV’s directives played a guarantee role. The formulation and implementation of the universal service policy in Vietnam were mainly concentrated on action at levels 2 and 3 (formal and informal institutional arrangement......, and formal institutional environment). The paper recommends that nations favouring a top-down approach not based on a market-oriented regime should deregulate and emphasize the role of provincial governments as well as encourage private sectors/social organizations and rural users to be more involved...

  5. Lightning protection for wind turbines in Vietnam

    Directory of Open Access Journals (Sweden)

    Thuan Nguyen

    2017-01-01

    Full Text Available Wind energy has become increasingly important in the total electrical energy supply mix in Vietnam over the last few years. Small, kW turbines were installed in isolated areas a decade ago, while wind farms of several MW to few hundred MW are now being connected directly to national grid, with many additional projects in planning or under construction to fulfill an objective of 6% of the total installed capacity by 2030 (approximately 6200 MW of wind energy component. The increase in wind farm generation results in increased damage from lightning. In this paper, the annual frequency of lightning strikes to wind turbines in Vietnam is calculated using electrogeometric model. Reported lightning incidents to three major wind farms in Vietnam are summarized. Possible causes of failure are discussed, and an EMTP simulation for each incident was performed accordingly. The simulations suggest the failure mechanisms as well the potential of improved grounding to reduce lightning induced damage in future windfarms.

  6. Women at war: The crucible of Vietnam

    Directory of Open Access Journals (Sweden)

    Anica Pless Kaiser

    2017-12-01

    Short-term (20 years; 12% and civilian women (13%. Additional differences regarding warzone experiences, homecoming support, and health outcomes were found among groups. All military and civilian women who served in Vietnam were less likely to have married or have had children than women from the general population, χ2 (8 = 643.72, p < .001. Career military women were happier than women in the general population (48% were “very happy”, as compared to 38%. Civilian women who served in Vietnam reported better health than women in the other groups. Regression analyses indicated that long-term physical health was mainly influenced by demographic characteristics, and that mental health and PTSD symptoms were influenced by warzone and homecoming experiences. Overall, this paper provides insight into the experiences of the understudied women who served in Vietnam, and sheds light on subgroup differences within the sample.

  7. Suicide of Australians during the Vietnam War.

    Science.gov (United States)

    Pridmore, Saxby; Ahmadi, Jamshid; Pridmore, William

    2018-04-01

    National suicide rates fall during times of war. This fits with the notion of the population coming together against a common foe. But, what happens in the case of a war which is not fully supported, which draws the population and families apart? We consider this question by examining the Australian suicide rates during the divisive Vietnam War. We graphed and examined the Australian suicide figures for 1921-2010. We found clear evidence of a decrease in the suicide rate for World War II (consistent with other studies), but a marked elevation of suicide during the Vietnam War. The elevation of the Australian suicide rate during the Vietnam War is consistent with Durkheim's social integration model - when social integration is lessened, either by individual characteristics or societal characteristics, the risk of suicide rises.

  8. Food Irradiation In Vietnam And Japan

    International Nuclear Information System (INIS)

    Tamikazy Kume

    2011-01-01

    In 2008, Japan Atomic Energy Commission of Cabinet Office performed the study of current status of food irradiation in the world. The results showed that the total quantity of irradiated foods in 2005 was 405,000 tons. Seven main countries for food irradiation were China, USA, Ukraine, Brazil, South Africa, Vietnam and Japan. In Japan, only the potato irradiation for sprout inhibition is continued more than 35 years since 1974 but the quantity is decreasing. On the other hand, the food irradiation of Vietnam has been developed rapidly in a short time to export the frozen seafood and fruit. This paper shows the status of food irradiation in Vietnam and Japan, and the progress in both countries after 2005. (author)

  9. Health issues in nursing in Vietnam.

    Science.gov (United States)

    Kristy, S J

    1995-01-01

    Major health concerns are not currently addressed in Vietnam as the country strives to upgrade its economic status. The current standard of medical care is rudimentary at best, as is the education and practice of Vietnamese nurses. The Ministry of Health in Vietnam has directed the Medical College of Hanoi to commence a 4-year degree in nursing in 1994. Historical, practical, political, economic, social, and cultural issues affect the development of nursing as a profession. Assistance from the West is sought by the Medical College in Hanoi.

  10. The role of trade unions in Vietnam

    DEFF Research Database (Denmark)

    Torm, Nina Elisabeth

    2014-01-01

    On the basis of matched employer–employee data from 2007 to 2009, this paper examines the union wage gap among small and medium non-state manufacturing enterprises in Vietnam. Controlling for both worker and firm characteristics, the results provide evidence that union members earn higher wages t...... than non-members, and are more likely to receive social benefits.Within unionised firms, a substantial wage premium is revealed for workers employed in Southern firms, a finding which among other factors may be attributed to historical differences between the North and South of Vietnam....

  11. Strategy in the Vietnam War: Western Concepts, Eastern Conflict and the Roots of Failure.

    Science.gov (United States)

    Weland, James

    1990-01-01

    Critiques U.S. military assumptions concerning the war in Vietnam. Discusses the North Vietnamese strategic approach to gaining control of South Vietnam. Traces the history of the Vietnam War, analyzing specific U.S. military operations in Vietnam and reasons for their failure. Contends that U.S. strategic ethnocentrism lead to defeat in Vietnam.…

  12. ÉTUDE DE CAS — Vietnam : Les communes du Vietnam ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    16 déc. 2010 ... Les communes du Vietnam progressent grâce à l'information Au Vietnam, un système de suivi communautaire de la pauvreté s'appuie sur des enquêtes officielles afin de mieux cibler les pauvres. Les données supplémentaires permettent d'améliorer la vie des collectivités, celle des femmes en particulier.

  13. Fast delta Hadamard transform

    International Nuclear Information System (INIS)

    Fenimore, E.E.; Weston, G.S.

    1981-01-01

    In many fields (e.g., spectroscopy, imaging spectroscopy, photoacoustic imaging, coded aperture imaging) binary bit patterns known as m sequences are used to encode (by multiplexing) a series of measurements in order to obtain a larger throughput. The observed measurements must be decoded to obtain the desired spectrum (or image in the case of coded aperture imaging). Decoding in the past has used a technique called the fast Hadamard transform (FHT) whose chief advantage is that it can reduce the computational effort from N 2 multiplies of N log 2 N additions or subtractions. However, the FHT has the disadvantage that it does not readily allow one to sample more finely than the number of bits used in the m sequence. This can limit the obtainable resolution and cause confusion near the sample boundaries (phasing errors). Both 1-D and 2-D methods (called fast delta Hadamard transforms, FDHT) have been developed which overcome both of the above limitations. Applications of the FDHT are discussed in the context of Hadamard spectroscopy and coded aperture imaging with uniformly redundant arrays. Special emphasis has been placed on how the FDHT can unite techniques used by both of these fields into the same mathematical basis

  14. Sustainable hydropower in Lower Mekong Countries: Technical assessment and training travel report

    Energy Technology Data Exchange (ETDEWEB)

    Hadjerioua, Boualem [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Witt, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-01

    The U.S. Agency for International Development (USAID), through their partnership with the U.S. Department of the Interior (DOI), requested the support of Oak Ridge National Laboratory (ORNL) to provide specialized technical assistance as part of the Smart Infrastructure for the Mekong (SIM) Program in Thailand. Introduced in July 2013 by U.S. Secretary of State John Kerry, SIM is a U.S. Government Inter-Agency program that provides Lower Mekong partner countries with targeted, demand-driven technical and scientific assistance to support environmentally sound, climate conscious and socially equitable infrastructure, clean energy development, and water resources optimization. The U.S. Government is committed to supporting sustainable economic development within the region by providing tools, best practices, technical assistance, and lessons learned for the benefit of partner countries. In response to a request from the Electricity Generating Authority of Thailand (EGAT), a SIM project was developed with two main activities: 1) to promote hydropower sustainability and efficiency through technical assessment training at two existing hydropower assets in Thailand, and 2) the design and implementation of one national and two or three regional science and policy workshops, to be co-hosted with EGAT, to build common understanding of and commitment to environmental and social safeguards for Mekong Basin hydropower projects. The U.S. Department of Energy (DOE) is leading the technical assessment (Activity 1), and has contracted ORNL to provide expert technical assistance focused on increasing efficiency at existing projects, with the goal of increasing renewable energy generation at little to no capital cost. ORNL is the leading national laboratory in hydropower analysis, with a nationally recognized and highly qualified team of scientists addressing small to large-scale systems (basin-, regional-, and national-scale) energy generation optimization analysis for DOE. The

  15. Energy deposition by delta rays

    International Nuclear Information System (INIS)

    Weigand, F.C.; Braby, L.A.

    1983-01-01

    Monte Carlo calculations for proton tracks were extended to projectile with more complex electronic structures which add additional delta ray production processes. An experimental apparatus was used to detect gas gain and resolution for H 2+ and 3 He ++

  16. Niger Delta Development Commission and Sustainable ...

    African Journals Online (AJOL)

    Niger Delta Development Commission and Sustainable Development of Niger Delta Region of Nigeria: The Case of Rivers State. Goddey Wilson. Abstract. The study is on Niger Delta Development Commission and sustainable development of Niger Delta region of Nigeria, the case of Rivers State. The main objective of the ...

  17. Developing Land Use Land Cover Maps for the Lower Mekong Basin to Aid SWAT Hydrologic Modeling

    Science.gov (United States)

    Spruce, J.; Bolten, J. D.; Srinivasan, R.

    2017-12-01

    This presentation discusses research to develop Land Use Land Cover (LULC) maps for the Lower Mekong Basin (LMB). Funded by a NASA ROSES Disasters grant, the main objective was to produce updated LULC maps to aid the Mekong River Commission's (MRC's) Soil and Water Assessment Tool (SWAT) hydrologic model. In producing needed LULC maps, temporally processed MODIS monthly NDVI data for 2010 were used as the primary data source for classifying regionally prominent forest and agricultural types. The MODIS NDVI data was derived from processing MOD09 and MYD09 8-day reflectance data with the Time Series Product Tool, a custom software package. Circa 2010 Landsat multispectral data from the dry season were processed into top of atmosphere reflectance mosaics and then classified to derive certain locally common LULC types, such as urban areas and industrial forest plantations. Unsupervised ISODATA clustering was used to derive most LULC classifications. GIS techniques were used to merge MODIS and Landsat classifications into final LULC maps for Sub-Basins (SBs) 1-8 of the LMB. The final LULC maps were produced at 250-meter resolution and delivered to the MRC for use in SWAT modeling for the LMB. A map accuracy assessment was performed for the SB 7 LULC map with 14 classes. This assessment was performed by comparing random locations for sampled LULC types to geospatial reference data such as Landsat RGBs, MODIS NDVI phenologic profiles, high resolution satellite data from Google Map/Earth, and other reference data from the MRC (e.g., crop calendars). LULC accuracy assessment results for SB 7 indicated an overall agreement to reference data of 81% at full scheme specificity. However, by grouping 3 deciduous forest classes into 1 class, the overall agreement improved to 87%. The project enabled updated LULC maps, plus more specific rice types were classified compared to the previous LULC maps. The LULC maps from this project should improve the use of SWAT for modeling

  18. Home Healthcare Program for Soil-Transmitted Helminthiasis in Schoolchildren along the Mekong River Basin.

    Science.gov (United States)

    Kaewpitoon, Soraya J; Loyd, Ryan A; Kaewpitoon, Natthawut

    2015-05-01

    Soil-transmitted helminths (STH) are among the most important groups of infectious agents responsible for physical and intellectual growth retardation in children worldwide. Current status is need requiredfor the development of control programs. To determine the STH infections among the schoolchildren in the Mekong River basin near rural Ubon Ratchathani, Thailand and Champassak, Laos PDR, including their caregiver knowledge and attitude concerning prevention of STH infections. A cross sectional survey was designed as a home healthcare programfrom October 2009 to April 2012. 1,957 fecal samples were collected from children aged 5-12 years in five districts of Ubon Ratchathani province (1,012 fecal samples; Khong Chiam, Si Mueang Mai, Phibun Mangsahan, Sirindhorn, and Pho Sai), Thailand, and one district of Champassak Province (945 fecal samples; Pakse), Lao PDR. Fecal samples were prepared by the modified formalin ethylacetate concentration technique, and determined by light microscope. The knowledge and attitude of children's caregivers concerning prevention of soil-transmitted helminth infections were completed interviewed by semi-structured questionnaires. The overall intestinal helminth prevalence rate was 11.88%. Classified by species the STHs were as follows: Ascaris lumbricoides (30.9%), Trichuris trichiura (21.7%), and hookworm (20.5%). The highest prevalence was recorded in children aged 9 years and above. The highest prevalence of STH infection was found in the Pakse district of Laos PDR (16.08%). The intensities of infection with A. lumbricoides, T trichiura, and Hookworm were 1.82 ± 0.36, 1.32 ± 0.30, and 1.29 ± 0.32, respectively. 1,077 of caregivers were completed interviewed and found that the caregivers had fair levels of knowledge and attitude regarding soil-transmitted helminthiasis. These results suggest that priority should be given to STH eradication, the development of control programs in the Mekong River Basin, and the provision of

  19. New Species of Orchids from Vietnam

    Directory of Open Access Journals (Sweden)

    Leonid V. Averyanov

    2007-12-01

    Full Text Available Identification of herbarium specimens collected in course of field exploration works in Vietnam during 2005-2007 revealed ten species of orchids new for science. Illustrated descriptions are provided for each discovered species, which are named as Anoectochilus papillosus, Arundina caespitosa, Bulbophyllum paraemarginatum, B. sinhoënse, Cheirostylis foliosa, Goodyera rhombodoides, Liparis rivularis, Oberonia multidentata, O. trichophora and Sunipia nigricans.

  20. Social networks and wage outcomes in Vietnam

    DEFF Research Database (Denmark)

    Larsen, Anna Folke; Torm, Nina Elisabeth

    2011-01-01

    This paper analyzes the relationship between the use of informal contacts and wage outcomes using matched employer-employee data from small and medium firms in Vietnam. We find that obtaining a job through knowing another worker in the firm generally is positively associated with individual wages...

  1. The Vietnam Vet's Battle--Unemployment

    Science.gov (United States)

    Werner, Wayne E.; Radcliff, Jo Ann

    1973-01-01

    The purpose of this article was to survey the employment situation of returning Vietnam veterans. The picture appears to be one of frustration. There are a number of programs available but a communications gap seems to exist between the programs and the veterans. (Author)

  2. Vietnam: A Failure of Strategy and Leadership

    Science.gov (United States)

    2013-04-30

    AND LEADERSHIP SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF MILITARY STUDIES AUTHOR: MAJOR D. M. CROUSORE, USMC...Q__ Date: ’::?:D l:foell 0<..01~ (/ i Executive Summary Title: VIETNAM: A FAILURE OF STRATEGY AND LEADERSHIP Author: Major D. M

  3. Decentralized forest governance in central Vietnam

    NARCIS (Netherlands)

    Tran Nam, T.; Burgers, P.P.M.

    2012-01-01

    A major challenge in decentralized forest governance in Vietnam is developing a mechanism that would support both reforestation and poverty reduction among people in rural communities. To help address this challenge, Forest Land Allocation (FLA) policies recognize local communities and individuals

  4. Governing pesticide in vegetable production in Vietnam

    NARCIS (Netherlands)

    Hoi, Van P.

    2010-01-01


    The economic liberalization in Vietnam, initiated in the middle of the 1980s, contributed to the further intensification and expansion of private actor-engagement in agriculture and food-supply. Vietnamese farmers, who already considered applying pesticides the most effective manner to protect

  5. Treatment Failure for Malaria in Vietnam

    Centers for Disease Control (CDC) Podcasts

    2017-06-05

    WHO malaria expert, Dr. Charlotte Rasmussen, discusses anti-malarial drug resistance in Vietnam.  Created: 6/5/2017 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 6/5/2017.

  6. Ichthyofauna of the reservoirs of Central Vietnam

    Directory of Open Access Journals (Sweden)

    I. A. Stolbunov

    2012-01-01

    Full Text Available Species composition, distribution and abundance of fish in the pelagic and littoral zone of four reservoirs of Central Vietnam (Suoi Chau, Kam Lam, Da Ban and Suoi Dau were studied first. According to the research data the fish community of the reservoirs is represented by 43 species of 19 fish families.

  7. Counting Women's Work in Vietnam | IDRC - International ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    2017-07-31

    Jul 31, 2017 ... These gender equality indicators are shedding light on girls' and women's ... Young people do a tremendous amount of unpaid care work at the ages when ... Read the report "Counting Women's Work in Vietnam" · View the ...

  8. The Vietnam War and the Media.

    Science.gov (United States)

    Elterman, Howard

    1988-01-01

    Surveys the author's contribution to the Center for Social Studies Education curriculum on the Vietnam War. Focuses on "How the War Was Reported," a unit which raises four questions concerning the responsibilities of the government and the press for keeping the public informed. Encourages use of the curriculum in teaching about the…

  9. The Vietnam War: History, Learning, and Leadership.

    Science.gov (United States)

    Edwards, Tricia

    2002-01-01

    Focuses on the curriculum entitled "Echoes from the Wall: History, Learning and Leadership through the Lens of the Vietnam War Era." Discusses the purpose of the materials. States that the curriculum incorporates primary resources into the classroom while making history more immediate to students. (CMK)

  10. Teaching the Vietnam War: A Conference Report.

    Science.gov (United States)

    Winterstein, Stephen

    2000-01-01

    On May 6-7, 2000, the Foreign Policy Research Institute's (FPRI's) sixth History Institute convened with more than 40 high school and college history teachers to seek answers to the question: "How should we teach the history of the Vietnam War to our children today?" Not surprisingly, no simple answers were forthcoming. This conference…

  11. The 2003 Merged Model for Vietnam

    DEFF Research Database (Denmark)

    Jensen, Henning Tarp; Tarp, Finn

    This monograph documents the 2003 Merged Model for Vietnam. The initialization and calibration of the model is based on a financial 2003 SAM framework and an auxiliary 2002-3 data set. The recursive nature of the solution of the Merged Model is discussed with reference to the four main sectors...

  12. Value Chain Development of Avocado in Vietnam

    NARCIS (Netherlands)

    Wertheim-Heck, S.C.O.; Quaedackers, P.; Nguyen Trung Anh,; Wijk, van S.

    2010-01-01

    Rapid economic development, urbanisation and rising income levels, in Vietnam offer potential for pro-poor development, by creating new market opportunities for producers, traders and retailers. This article describes the process of value chain development, which involves all actors in the broad

  13. Environmental considerations in Vietnam's energy policy

    International Nuclear Information System (INIS)

    Bui, X.H.

    2007-01-01

    Energy conservation is at the centre of an environmental debate in Vietnam, whose rapidly growing economy in recent years has resulted in rising energy consumption and environmental degradation. This article reviewed the actual state of Vietnam's energy system, with consideration of the country's energy policies and their impact on the environment. Vietnam's energy resources consist of a vast network of rivers that hold potential for hydroelectric power; reserves that are proven to have oil, natural gas and coal; and, other renewable energy sources such as wind and solar energy. The energy sector plays a major role in the economic and social aspects of the country. Since its economic reform, coal and crude oil exports have brought in foreign money to the national revenue. Vietnam exploits four commercial types of energy, namely coal, oil, natural gas and hydroelectricity. These traditional energy sources play a major role in providing energy for the rural and mountainous regions in the country. The increase in energy demand in Vietnam is currently greater than that of its gross national product. The energy intensity in Vietnam is 1.5 times greater than that of Thailand, and twice the average world consumption. Energy demands are increasing at a regular rate due to a low rate of energy efficiency and to growth in industrialization and modernization. In addition, the government provides subsidies to the already low price of energy. It was concluded that although Vietnam has a low rate of energy consumption compared to other regions of the world, there exists a serious imbalance between energy use and economic and social growth. This imbalance could have a negative impact on fossil resources and the environment, especially if the high demand for energy is maintained. Presently, all negative impacts on the environment are related to the energy sector. An environmental assessment and strategic proposals to manage this problem locally and globally, have constituted the

  14. On nuclear manpower development in Vietnam

    International Nuclear Information System (INIS)

    Phung Van Duan

    2007-01-01

    Vietnam began to be interested in education and training on nuclear sciences and related subjects since the early 1960's. A department of Nuclear Physics and Engineering was established in 1970 at the Hanoi University of Technology (HUT), which is the biggest interdisciplinary technological education centre of the country. In Vietnam there are several institutions where exist programmes of education on nuclear sciences and nuclear engineering. But HUT has been being since 1970 the only institution that has underway programme of education on nuclear engineer degree. Although the Department was renamed and its education programme was adjusted, but the objectives of its education programme have been being followed without changes. These objectives are as follows: 1) To develop peaceful applications of atomic energy in Vietnam; 2) To train up engineers on nuclear instrumentation for supporting the first objective; and 3) To prepare initial manpower for introduction of Nuclear Power in Vietnam. Nuclear community of Vietnam is still not so large. Total number of its members increased until 1986, and then decreases up to now. Present average age of members of the community is of 45. In 15 coming years at least 500-700 young people must be educated on programmes on nuclear engineer degree and on nuclear bachelor degree. This is a very difficult task for a developing country such as Vietnam. From a point of view of development, the above-mentioned number is too small, and it must be much more. This makes the task much more difficult. In addition, education on nuclear engineering in the country at present is in a hard situation because of lacking in experienced people, as well as in teaching material and equipment, and, because of weakness of the education programme. So, it may be impossible to achieve success in realization of the task without a large and effective international cooperation in education on nuclear science and engineering. That is why the Asian Network for

  15. $\\delta$-Expansion at Finite Temperature

    OpenAIRE

    Ramos, Rudnei O.

    1996-01-01

    We apply the $\\delta$-expansion perturbation scheme to the $\\lambda \\phi^{4}$ self-interacting scalar field theory in 3+1 D at finite temperature. In the $\\delta$-expansion the interaction term is written as $\\lambda (\\phi^{2})^{ 1 + \\delta}$ and $\\delta$ is considered as the perturbation parameter. We compute within this perturbative approach the renormalized mass at finite temperature at a finite order in $\\delta$. The results are compared with the usual loop-expansion at finite temperature.

  16. 31 CFR 500.560 - Bank accounts of official representatives of foreign governments in North Korea, North Viet-Nam...

    Science.gov (United States)

    2010-07-01

    ... representatives of foreign governments in North Korea, North Viet-Nam, Cambodia, or South Viet-Nam. 500.560... governments in North Korea, North Viet-Nam, Cambodia, or South Viet-Nam. Specific licenses are issued... Viet-Nam, Cambodia, or South Viet-Nam for transactions which are not inconsistent with the purposes of...

  17. Anaerobic Transformation of Furfural by Methanococcus deltae (Delta)LH

    Science.gov (United States)

    Belay, N.; Boopathy, R.; Voskuilen, G.

    1997-01-01

    Methanococcus deltae (Delta)LH was grown on H(inf2)-CO(inf2) in the presence of various concentrations of furfural. Furfural at higher concentrations, namely, 20 and 25 mM, inhibited growth of this organism. At concentration of 5 and 10 mM, no inhibition of growth was observed. The other methanogens in this study were not inhibited by 10 mM furfural. Among the methanogens tested, M. deltae was capable of transforming furfural, whereas Methanobacterium thermoautotrophicum Marburg, Methanosarcina barkeri 227, Methanococcus thermolithotrophicus, and Methanobrevibacter ruminantium lacked this capability. One hundred percent removal of furfural was observed within 48 h of incubation in M. deltae cultures. The end product observed during furfural metabolism was furfuryl alcohol. An almost stoichiometric amount of furfuryl alcohol was produced by M. deltae. This transformation is likely to be of value in the detoxification of furfural and in its ultimate conversion to methane and CO(inf2) by anaerobic digestion. PMID:16535618

  18. Meiobenthos assemblages in the mekong estuarine system with special focus on free-living marine nematodes

    Science.gov (United States)

    Quang, Ngo Xuan; Vanreusel, Ann; Smol, Nic; Chau, Nguyen Ngoc

    2010-12-01

    Meiobenthos assemblages in eight estuaries of the Mekong river system were investigated in August 2008 (from the Cua Tieu estuary to the Tran De estuary). In each estuary, one sampling station was established for meiobenthos sampling. Twelve major taxa of meiobenthos were recorded in this estuarine system, including Nematoda, Copepoda, Turbellaria, Polychaeta, Oligochaeta, Tardigrada, Bivalvia, Ostracoda, Amphipoda, Cumacea, Gastrotricha, Gastropoda, and Crustacean Nauplii larvae. The densities of the meiobenthos range from 581 to 3168 inds/10 cm2. Nematodes always occupy the highest numbers with a percentage ranging from 64-99%. There are 135 nematode genera recorded in this study with the following as dominant genera Desmodora, Leptolaimus, Halalaimus, Thalassomonhystera, Theristus, Daptonema, Rhynchonema, Parodontophora, and Oncholaimus. Although the biodiversity of the meiobenthos at higher taxa level is not high compared to other marine environments, the estimates of nematode biodiversity at the genus level indicates high values. The increase in number of genera with increasing sampling intensity illustrate that the diversity is underestimated and would have been higher if the authors had considered a larger number of individuals, more replicates per station, and more sampling stations.

  19. Mapping Precipitation in the Lower Mekong River Basin and the U.S. Affiliated Pacific Islands

    Science.gov (United States)

    Lakshmi, V.; Sutton, J. R. P.; Bolten, J. D.

    2017-12-01

    Mapping and quantifying precipitation across varying temporal and spatial scales is of utmost importance in understanding, monitoring, and predicting flooding and drought. While there exists many in-situ precipitation gages that can accurately estimate precipitation in a given location, there are still many areas that lack in-situ gages. Many of these locations do not have precipitation gages because they are rural and/or topographically complex. The purpose of our research was to compare different remotely sensed satellite precipitation estimates with in-situ estimates across topographically complex and rural terrain within the United States Affiliated Pacific Islands (USAPI) and the Lower Mekong River Basin (LMRB). We utilize the publicly available Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN) Climate Data Record (CDR) from NOAA and two remotely sensed precipitation products from NASA; the Tropical Rainfall Measuring Mission (TRMM) and the Global Precipitation Measurement (GPM). These precipitation estimates were compared with each other and to the available in-situ precipitation estimates from station gages. We also utilize NASA Landsat data to determine the land cover types of these study areas. Using the precipitation estimates, topography, and the land cover of the study areas, we were able to show areas experiencing differing amounts of rainfall and their agreement with in-situ estimates. Additionally, we study the seasonal and spatial trends in precipitation. These analyses can be used to help understand areas that are experience frequent flood or drought.

  20. Molecular characterization of sympatrically distributed Neotricula aperta-like snails in the Mekong River, Kratie, Cambodia.

    Science.gov (United States)

    Wang, Chennan; Saijuntha, Weerachai; Kirinoki, Masashi; Hayashi, Naoko; Chigusa, Yuichi; Muth, Sinuon; Meng, Chuor Char; Ai, Yingchun; Agatsuma, Takeshi

    2016-01-01

    Fifty-six samples of Neotricula aperta-like snails were collected from six locations in Cambodia. Their mitochondrial cytochrome c oxidase subunit 1 (cox1) sequences were examined using haplotype network and neighbor-joining (NJ) tree analysis. Twenty-seven haplotypes (H1-H27) were observed and were divided into two different groups/lineages. Of 27, 17 haplotypes (H11-H27) were clustered with the reference samples of the γ-race N. aperta. The remaining 10 haplotypes (H1-H10) were clustered in a separate group/lineage, differing from the reference samples of the α-, β-, and γ-race N. aperta, suggesting a new lineage belonging the genus Neotricula. Our results show that both the γ-race and a new lineage were sympatrically present approximately 60 km upstream of the Mekong River near the Kratie port, Cambodia. Further morphological and molecular studies are required to confirm the taxonomic status of this new, unidentified lineage.

  1. Biofuels and the Greater Mekong Subregion: Assessing the impact on prices, production and trade

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jun; Huang, Jikun; Qiu, Huanguang [Center for Chinese Agricultural Policy, Chinese Academy of Sciences and Institute of Geographical Sciences and Natural Resources Research, Jia 11, Datun Road, Beijing 100101 (China); Rozelle, Scott [Freeman Spogli Institute of International Studies, Stanford University, East Encina Hall, Stanford, CA 94305 (United States); Sombilla, Mercy A. [Southeast Asian Regional Center for Graduate Study and Research in Agriculture, College, Laguna 4031 (Philippines)

    2009-11-15

    Similar to many other countries, all nations in the Greater Mekong Subregion (GMS) have planned or are planning to develop strong national biofuel programs. The overall goal of this paper is to better understand the impacts of global and regional biofuels on agriculture and the rest of the economy, with a specific focus on the GMS. Based on a modified multi-country, multi-sector computable general equilibrium model, this study reveals that global biofuel development will significantly increase agricultural prices and production and change trade in agricultural commodities in the GMS and the rest of world. While biofuel in the GMS will have little impacts on global prices, it will have significant effects on domestic agricultural production, land use, trade, and food security. The results also show that the extent of impacts from biofuel is highly dependent on international oil prices and the degree of substitution between biofuel and gasoline. The findings of this study have important policy implications for the GMS countries and the rest of world. (author)

  2. Biofuels and the Greater Mekong Subregion: Assessing the impact on prices, production and trade

    International Nuclear Information System (INIS)

    Yang, Jun; Huang, Jikun; Qiu, Huanguang; Rozelle, Scott; Sombilla, Mercy A.

    2009-01-01

    Similar to many other countries, all nations in the Greater Mekong Subregion (GMS) have planned or are planning to develop strong national biofuel programs. The overall goal of this paper is to better understand the impacts of global and regional biofuels on agriculture and the rest of the economy, with a specific focus on the GMS. Based on a modified multi-country, multi-sector computable general equilibrium model, this study reveals that global biofuel development will significantly increase agricultural prices and production and change trade in agricultural commodities in the GMS and the rest of world. While biofuel in the GMS will have little impacts on global prices, it will have significant effects on domestic agricultural production, land use, trade, and food security. The results also show that the extent of impacts from biofuel is highly dependent on international oil prices and the degree of substitution between biofuel and gasoline. The findings of this study have important policy implications for the GMS countries and the rest of world. (author)

  3. Hydrographic survey of Chaktomuk, the confluence of the Mekong, Tonlé Sap, and Bassac Rivers near Phnom Penh, Cambodia, 2012

    Science.gov (United States)

    Dietsch, Benjamin J.; Densmore, Brenda K.; Wilson, Richard C.

    2014-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Department of State, Mekong River Commission, Phnom Penh Autonomous Port, and the Cambodian Ministry of Water Resources and Meteorology, completed a hydrographic survey of Chaktomuk, which is the confluence of the Mekong, Tonlé Sap (also spelled Tônlé Sab), and Bassac Rivers near Phnom Penh, Cambodia. The hydrographic survey used a high-resolution multibeam echosounder mapping system to map the riverbed during April 21–May 2, 2012.

  4. Use of physical/chemical mutagens in plant breeding program in Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Tran Duy Quy; Nguyen Huu Dong; Bui Huy Thuy; Le Van Nha; Nguyen Van Bich [Agricultural Genetics Institute, Hanoi (Viet Nam)

    2001-03-01

    Among more than 1870 new plant varieties formed by mutation breeding in the world, 44 varieties of different plants were formed by Vietnamese scientists. Research on induced mutation in Vietnam started in 1966, was promoted in Agricultural Institute, Cuu Long Delta Rice Research Institute, Institute of Food Crop Research, and Agriculture Universities, and has produced varieties of rice, maize, soybean, peanut, tomato, jujuba, green bean etc using physical and chemical mutagens: Irradiation with gamma rays or neutrons, and use of such chemicals as dimethylsulfate (DMS), diethylsulfate (DES), ethyleneimine (EI), N-nitrosomethylurea (NUM), N-nitrosoethylurea (NEU), and sodium azide (NaN{sub 3}). In the present report, the results of cytological and genetic effects in M1 plants, the frequency and spectrum of chlorophyll and morphological mutants, the mutants obtained and the genetic nature of the next generation are described, particularly for the case of rice. Radiation dose and dose rate used as mutagens are also reported. (S. Ohno)

  5. Use of physical/chemical mutagens in plant breeding program in Vietnam

    International Nuclear Information System (INIS)

    Tran Duy Quy; Nguyen Huu Dong; Bui Huy Thuy; Le Van Nha; Nguyen Van Bich

    2001-01-01

    Among more than 1870 new plant varieties formed by mutation breeding in the world, 44 varieties of different plants were formed by Vietnamese scientists. Research on induced mutation in Vietnam started in 1966, was promoted in Agricultural Institute, Cuu Long Delta Rice Research Institute, Institute of Food Crop Research, and Agriculture Universities, and has produced varieties of rice, maize, soybean, peanut, tomato, jujuba, green bean etc using physical and chemical mutagens: Irradiation with gamma rays or neutrons, and use of such chemicals as dimethylsulfate (DMS), diethylsulfate (DES), ethyleneimine (EI), N-nitrosomethylurea (NUM), N-nitrosoethylurea (NEU), and sodium azide (NaN 3 ). In the present report, the results of cytological and genetic effects in M1 plants, the frequency and spectrum of chlorophyll and morphological mutants, the mutants obtained and the genetic nature of the next generation are described, particularly for the case of rice. Radiation dose and dose rate used as mutagens are also reported. (S. Ohno)

  6. Simulation and optimisation modelling approach for operation of the Hoa Binh Reservoir, Vietnam

    DEFF Research Database (Denmark)

    Ngo, Long le; Madsen, Henrik; Rosbjerg, Dan

    2007-01-01

    Hoa Binh, the largest reservoir in Vietnam, plays an important role in flood control for the Red River delta and hydropower generation. Due to its multi-purpose character, conflicts and disputes in operating the reservoir have been ongoing since its construction, particularly in the flood season....... This paper proposes to optimise the control strategies for the Hoa Binh reservoir operation by applying a combination of simulation and optimisation models. The control strategies are set up in the MIKE 11 simulation model to guide the releases of the reservoir system according to the current storage level......, the hydro-meteorological conditions, and the time of the year. A heuristic global optimisation tool, the shuffled complex evolution (SCE) algorithm, is adopted for optimising the reservoir operation. The optimisation puts focus on the trade-off between flood control and hydropower generation for the Hoa...

  7. Pesticide distribution and use in vegetable production in the Red River Delta of Vietnam

    NARCIS (Netherlands)

    Pham Van Hoi,; Mol, A.P.J.; Oosterveer, P.J.M.; Brink, van den P.J.

    2009-01-01

    For a long time pesticides attracted interest from the Vietnamese governments and farmers for their positive effects in protecting crop yield losses resulting from pests and other plant diseases. Recently, the negative effects of pesticides on human health, natural food chains and the environment

  8. Social media for non-profit organizations in Vietnam

    OpenAIRE

    Nguyen, Thy

    2016-01-01

    The thesis presents about social media in general and social media for non-profit organizations in Vietnam in particular. The writer wanted to explore the disadvantages that non-profits in Vietnam face when using social media and search for recommendations which helps them to use it more efficiently. In the theoretic part, core concepts related to social media were introduced, namely, definition of social media, its types, the popular platforms, situation of social media in Vietnam, pros...

  9. Improving quality of foreign direct investment attraction in Vietnam

    OpenAIRE

    Ngo Phuc Hanh; Đao Van Hùng; Nguyen Thac Hoat; Dao Thi Thu Trang

    2017-01-01

    Foreign direct investment (FDI) enterprises are playing a key role in Vietnam's economy. By the end of 2016, there are more than 21,398 FDI projects in force, with the total registered capital of nearly 293 billion USD. One hundred six countries and territories have invested in 19 industries in 68 provinces and cities of Vietnam. These investments have added a large amount of capital to the economy, which has basically been used effectively, contributing to the economic growth of Vietnam. In ...

  10. The Economic Impact of Land Use Rights in Rural Vietnam

    Science.gov (United States)

    2013-11-01

    Rental Markets In Transition: Evidence From Rural Vietnam." Oxford Bulletin Of Economics And Statistics 70, no. 1: 67- 101. ECONIS, EBSCOhost ...Rental Markets In Transition: Evidence From Rural Vietnam." Oxford Bulletin Of Economics And Statistics 70, no. 1: 67- 101. ECONIS, EBSCOhost ...generating revenue through taxation in a previously non-existent real estate market . Before 1993, Vietnam experienced a long period of land reform

  11. Suspended futures : the Vietnamization of South Vietnamese history and memory

    OpenAIRE

    Bui, Long Thanh

    2011-01-01

    In 1969, President Richard Nixon announced the "Vietnamization" of the Vietnam War, a handover of responsibility for winning the war from the U.S. to its allies, the South Vietnamese. Vietnamization articulated the challenges of achieving political freedom and historical agency for South Vietnamese people. Conceptualizing this term in the early 21st century, I seek to address the ways the war (and its subjects) is called into the present to speak about the representability and addressability ...

  12. A Comparative Analysis of Unit Cohesion in Vietnam

    Science.gov (United States)

    2014-06-13

    winning” the war in Vietnam. One only needs to turn to cinema to see the divide and portrayal of the Vietnam conflict. Movies like, Platoon...disapproved of post-war (World War II) re-colonization, especially the French efforts in Indochina that included Cambodia, Laos and Vietnam. He offered...the political process, and result in a communist government; this became known as the Domino Theory. The United States replaced the French and

  13. Vietnam seeks help expanding voluntary surgical contraception.

    Science.gov (United States)

    Piet-pelon, N J; Sukop, S

    1992-07-01

    Recent surveys by the Vietnamese Ministry of Health suggest that 60% of married women desire no more children. Yet only 2% of currently married women and less than 1/2 of 1% of their partners use sterilization. Underscoring the high unmet need for effective family planning, over 1 million abortions (legal in Vietnam for the past 20 years) are performed annually. This rate corresponds to 1 abortion for every live birth. The Ministry of Health has recently welcomed a variety of organizations, including AVSC, whose assistance can help expand the country's family planning programs. Sorely lacking in supplies, equipment, and trained personnel, Vietnam has merited priority status--2nd only to China and India--from the UNFPA, which has committed $36 million over the next 4 years. Other organizations currently working in Vietnam include the Population Council, the Population Crisis Committee, and the International Planned Parenthood Federation. Despite enormous casualties during the war years, and a decrease since the 1970s in average family size from 6 to 4 children, the population of Vietnam has continued to grow rapidly, far outpacing economic growth. Currently 67 million, the population is expected to reach 80 million by the year 2000. The average Vietnamese annual income is only $195, among the lowest in the world. Doi moi, the process of economic reform begun in 1986, coupled with new government incentives for families who have no more than 2 children, is changing the face of family planning in Vietnam. Newly opened pharmacies sell imported birth control pills and condoms (to those who can afford them), while government hospitals and health clinics provide mainly IUDs, in addition to limited supplies of pills and condoms. Throughout the country, some 8000 community-level health centers are staffed by nurse-midwives trained in family planning. Voluntary sterilization is available at the district, provincial, and national hospitals. All married women may obtain family

  14. Modelling Hydrologic Processes in the Mekong River Basin Using a Distributed Model Driven by Satellite Precipitation and Rain Gauge Observations.

    Science.gov (United States)

    Wang, Wei; Lu, Hui; Yang, Dawen; Sothea, Khem; Jiao, Yang; Gao, Bin; Peng, Xueting; Pang, Zhiguo

    2016-01-01

    The Mekong River is the most important river in Southeast Asia. It has increasingly suffered from water-related problems due to economic development, population growth and climate change in the surrounding areas. In this study, we built a distributed Geomorphology-Based Hydrological Model (GBHM) of the Mekong River using remote sensing data and other publicly available data. Two numerical experiments were conducted using different rainfall data sets as model inputs. The data sets included rain gauge data from the Mekong River Commission (MRC) and remote sensing rainfall data from the Tropic Rainfall Measurement Mission (TRMM 3B42V7). Model calibration and validation were conducted for the two rainfall data sets. Compared to the observed discharge, both the gauge simulation and TRMM simulation performed well during the calibration period (1998-2001). However, the performance of the gauge simulation was worse than that of the TRMM simulation during the validation period (2002-2012). The TRMM simulation is more stable and reliable at different scales. Moreover, the calibration period was changed to 2, 4, and 8 years to test the impact of the calibration period length on the two simulations. The results suggest that longer calibration periods improved the GBHM performance during validation periods. In addition, the TRMM simulation is more stable and less sensitive to the calibration period length than is the gauge simulation. Further analysis reveals that the uneven distribution of rain gauges makes the input rainfall data less representative and more heterogeneous, worsening the simulation performance. Our results indicate that remotely sensed rainfall data may be more suitable for driving distributed hydrologic models, especially in basins with poor data quality or limited gauge availability.

  15. Sinking Deltas are Trapped in a Dual Lock-in of Technology and Institutions: Exploring the Trap and 3 Steps to Break Out.

    Science.gov (United States)

    Seijger, C.; Janssen, S.; Erkens, G.

    2017-12-01

    Although the topic of sinking deltas has been put convincingly in the academic spotlight, we consider it highly unlikely that neither subsidence nor the resulting damage will reduce in the near future as subsiding deltas are trapped in a dual lock-in of technology and institutions. People, and the engineering technologies they have applied, are root causes for sinking deltas worldwide. To serve growing economics and populations, conventional water management strategies have increasingly been implemented (more dikes, dams, groundwater pumping, land reclamation) that cause, exacerbate, or facilitate subsidence. The increasing implementation of these strategies enlarged the power of those implementing it: in the US, an increase in dam and levee construction projects meant an increase in power of the US Army Corps of Engineers; in groundwater irrigation, rich farmers have the capacity to monopolise groundwater over poorer farmers; and key beneficiaries of more hydropower projects in China are the hydropower companies. Nine factors for the lock-in are introduced and illustrated for delta regions in Asia, Europe, and the US. The lock-in factors describe financial, social and technological reasons why certain institutions and technologies become dominant over alternatives. Sinking deltas like the Mekong or Mississippi Delta are thus trapped in a dual lock-in and on a self-reinforcing path of delta development with increasing areas of deltas sinking below sea level. Due to the persistency of these developments, pathways for change are needed. We propose three steps to break the dual lock-in (see Figure): (1) getting to know the lock-in through transdisciplinary research (2 years) (2) temporarily bypass it through experiments in technology and institutions (10 years) (3) constitute a new, more sustainable lock-in by mainstreaming shifts in technology and institutions (10-50 years) The dual lock-in concept offers a novel integrated understanding on sinking deltas

  16. Application of Virtual Rain and Stream Gauge Information Service for Improved Flood Early Warning System in Lower Mekong Countries

    Science.gov (United States)

    Basnayake, S. B.; Jayasinghe, S.; Meechaiya, C.; Markert, K. N.; Lee, H.; Towashiraporn, P.; Anderson, E.; Okeowo, M. A.

    2017-12-01

    Asia is the most vulnerable region in the world to hydro-meteorological extreme events, exacerbated by climate variability and change. Impacts of floods have been on the rapid increase in the recent decades. Myanmar is one of the most vulnerable countries in the lower Mekong region due to its socioeconomic situation (eg; Nargis in 2008, monsoon floods in 2015, etc). Early warning is an effective way to prepare for hydro-meteorological hazards, to minimize disaster risks; however, early warning systems in Myanmar are seriously hampered by limited observation networks. The Virtual Rain and Stream Gauge Information Service (VRSGIS) has been developed by SERVIR-Mekong program of Asian Disaster Preparedness Center (ADPC) to address these gaps and to provide dense, satellite-based rainfall and water level data, which are calibrated and validated with available in-situ observations. This service would enhance decision making in lower Mekong countries, including Myanmar, to minimize impacts of impending disasters. This service contains rainfall data from GPM IMERG and GSMap, CMORPH, TRMM, and CHIRPS, and water levels for 15 locations using Jason-2/3 altimetry. The virtual daily rainfall data sets are being calibrated with Gamma distribution method and are made publicly accessible through a user-friendly web interface.This paper presents a case study of satellite-derived rainfall data accessed from VRSGIS for hydrological modeling in Myanmar, to estimate inundation areas in Kalay township area of Chindwin River basin during the country's worst flood in 2015. Twelve out of fourteen States of Myanmar were severely affected, 103 people were killed, and one million were displaced due to heavy rains associated with Komen cyclone. The aforementioned rainfall data products are used as inputs for HEC-HMS hydrological runoff model to calculate river flows along Chindwin River, and HEC-RAS hydraulic model is used to estimate inundation areas in downstream including Kalay township

  17. Four new Delta Scuti stars

    Science.gov (United States)

    Schutt, R. L.

    1991-01-01

    Four new Delta Scuti stars are reported. Power, modified into amplitude, spectra, and light curves are used to determine periodicities. A complete frequency analysis is not performed due to the lack of a sufficient time base in the data. These new variables help verify the many predictions that Delta Scuti stars probably exist in prolific numbers as small amplitude variables. Two of these stars, HR 4344 and HD 107513, are possibly Am stars. If so, they are among the minority of variable stars which are also Am stars.

  18. Posttraumatic stress disorder among black Vietnam veterans.

    Science.gov (United States)

    Allen, I M

    1986-01-01

    Because of racism in the military and racial and social upheaval in the United States during the Vietnam War years, as well as limited opportunities for blacks in the postwar period, black veterans of the Vietnam War often harbor conflicting feelings about their wartime experiences and have difficulty rationalizing brutality against the Vietnamese. As a result, black veterans suffer from posttraumatic stress disorder (PTSD) at a higher rate than white veterans. Diagnosis and treatment of PTSD in black veterans is complicated by the tendency to misdiagnose black patients, by the varied manifestations of PTSD, and by patients' frequent alcohol and drug abuse and medical, legal, personality, and vocational problems. The author presents his and others' recommendations about ways to treat black veterans with PTSD.

  19. Clinical microbiology during the Vietnam War.

    Science.gov (United States)

    Washington, Michael; Brown, Matthew; Palys, Thomas; Tyner, Stuart; Bowden, Robert

    2009-11-01

    During the period of 1965-1968, over two dozen Army microbiologists were deployed to various locations in Southeast Asia in support of the Vietnam War. Their role was to serve both a clinical laboratory mission/function at the mobile Army surgical hospital and mobile laboratory level as well as to perform research roles in all of the facilities. They were essential to the formulation of medical intelligence as well as to the practice of operational medicine in the deployed environment. The results of their laboratory investigations provided commanders and military physicians with critical medical information for patient care, outbreak investigation, and forensic analysis. As with many soldiers in support of the infantry and armor combat forces, most of the work occurs behind the scenes and their contributions are often left out of the historical literature. This article presents a brief overview of microbiology performed by Army microbiologists during the Vietnam War.

  20. Experimental nuclear physics in Vietnam - recent status

    International Nuclear Information System (INIS)

    Tran Thanh Minh

    1995-01-01

    It is really difficult to determine the exact date for the starting of nuclear physics research in Vietnam. Serious research on experimental nuclear physics began only since 1972 with the installation of such nuclear instrument like microtron accelerator, neutron generator, etc. During the past 20 years, hundred of research works have been published in local and foreign scientific journals. In the 5th national conference in Physics held in Hanoi in October 1993, at the Nuclear Physics section, 62 reports were presented reflecting the situation of nuclear physics research in the recent years, especially in the past five years. This review introduces its main results and formulates some perspectives of development in the late nineties in Vietnam. (K.A.). 27 refs., 4 figs., 6 tabs

  1. Vegetation fires and air pollution in Vietnam.

    Science.gov (United States)

    Le, Thanh Ha; Thanh Nguyen, Thi Nhat; Lasko, Kristofer; Ilavajhala, Shriram; Vadrevu, Krishna Prasad; Justice, Chris

    2014-12-01

    Forest fires are a significant source of air pollution in Asia. In this study, we integrate satellite remote sensing data and ground-based measurements to infer fire-air pollution relationships in selected regions of Vietnam. We first characterized the active fires and burnt areas at a regional scale from MODIS satellite data. We then used satellite-derived active fire data to correlate the resulting atmospheric pollution. Further, we analyzed the relationship between satellite atmospheric variables and ground-based air pollutant parameters. Our results show peak fire activity during March in Vietnam, with hotspots in the Northwest and Central Highlands. Active fires were significantly correlated with UV Aerosol Index (UVAI), aerosol extinction absorption optical depth (AAOD), and Carbon Monoxide. The use of satellite aerosol optical thickness improved the prediction of Particulate Matter (PM) concentration significantly. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Vietnam Land Policy - Adjusting to Globalization

    Science.gov (United States)

    2013-11-01

    the Late- Socialist Period," Pacific Affairs: vol 84, no. 3, (2011): 439-440, accessed 30 September 2013, EBSCO Discovery Service . 37 U.S...Society,” Contemporary Southeast Asia vol 31, no. 1 (2009): 21, accessed 15 October 2013, EBSCO Discovery Service . 81 Legal Information... EBSCO Discovery Service . Fforde, Adam. "Vietnam in 2012: The End of the Party." Asian Survey 53, no. 1 (2013): 101-108. Accessed 30

  3. Income Inequality and Migration in Vietnam

    OpenAIRE

    NGUYEN, Tien Dung

    2012-01-01

    In this paper, we have analyzed the recent trends in income inequality, internal and international migrations and investigated the impact of migration on income distribution in Vietnam. Our analysis shows that the effects of migration on income inequality vary with different types of migration, depending on who migrate and where they migrate. Foreign remittances tend to flow toward more affluent households, and they increase income inequality. By contrast, domestic remittances accrue more to ...

  4. Vietnam on the path of nuclear energy

    International Nuclear Information System (INIS)

    Svolik, S.

    2013-01-01

    Exchange of information, experience sharing, an external view on the condition of equipment and activities in nuclear power plants, recommendations for improvement, transfer of best practice and benchmarking - that is the benefit of sharing at various levels by the specialists and experts from nuclear power plants around the world. One of the events was the national workshop on quality assurance and control during the construction and commissioning of a nuclear power plant in Vietnam. (author)

  5. Viral Advertising on Facebook in Vietnam

    OpenAIRE

    Tran, Phuong

    2014-01-01

    The purpose of this thesis is to explore which factors affect the effectiveness of viral advertising on Facebook in Vietnam. The quantitative research method is applied in this research and the sample is Vietnamese Facebook users. After the data analysis stage using SPSS, it became clear that weak ties, perceptual affinity and emotions have an impact on the effectiveness of viral advertising. The results provide a pratical implication of how to make an Ad which can go viral on Facebook. Moreo...

  6. Macroeconomic Forces and Stock Returns in Vietnam

    OpenAIRE

    Phan, Van Hang

    2008-01-01

    Capital market development, especially the appearance of Vietnamese equity market recently has a strategic importance in the economic growth and structural reform process of Vietnam (Chun et al, 2003). This dissertation focuses on the impacts of macroeconomic forces on stock market returns in Vietnamese stock market which has not been investigated in detail before, and thereby to contribute further literature on this new emerging stock market. Specifically, the research will intensively inves...

  7. VIETNAM IN 1948: AN INTERNATIONAL HISTORY PERSPECTIVE

    Directory of Open Access Journals (Sweden)

    Ang Cheng Guan

    2009-01-01

    Full Text Available This paper revisits the year 1948 in an effort to determine whether 1948 can be considered the starting point of the Cold War in Vietnam. Historical periodisation is a tricky affair, and it is often difficult to pinpoint the genesis of events. By reconstructing the political and military developments in 1948 from the indigenous perspective as well as from regional and international perspectives that directly impinged on Vietnam, I hope to ascertain whether Vietnam’s war of liberation was indeed transformed into a “Cold War” from 1948 onwards—in other words, whether it was in 1948 that the Vietnamese struggle assumed an ideological complexion that shifted from nationalist/anti-colonial sentiment to include communist/anti-capitalist sentiment as well. Before we embark on our consideration of the year 1948, it is useful to recount in broad brush-strokes some key developments in Vietnam leading up to 1948. In order to put the year 1948 in context, it is also necessary to consider in some detail two key developments in 1947.

  8. Social phobia and PTSD in Vietnam veterans.

    Science.gov (United States)

    Orsillo, S M; Heimberg, R G; Juster, H R; Garrett, J

    1996-04-01

    Posttraumatic stress disorder (PTSD) is the most prevalent psychological disorder experienced by Vietnam veterans. However, there are many other disorders and problems of adjustment, like social anxiety and social phobia, that have not been fully investigated in this population. This study examined the prevalence of social phobia and the comorbidity of social phobia and PTSD, and tested out a theory of the etiology of social anxiety in trauma victims. Forty one Vietnam combat veterans were interviewed and completed self-report measures assessing PTSD and social phobia. Adversity of homecoming was also assessed. Using a conservative multi-method assessment approach, 32% of the sample were found to be positive for both social phobia and PTSD. Veterans with PTSD were significantly more likely to carry an additional diagnosis of social phobia as compared to veterans without PTSD. Adversity of homecoming and shame about one's experience in Vietnam were significant predictors of current level of social anxiety over and above the effects of pre-military anxiety and severity of combat exposure. These observations suggest that social anxiety and social phobia may be significant problems among individuals with PTSD. Further, these findings offer preliminary support for the theory that posttrauma environment may impact upon the later development of social anxiety.

  9. Land Use and Water Quality Along a Mekong Tributary in Northern Lao P.D.R.

    Science.gov (United States)

    Ribolzi, Olivier; Cuny, Juliette; Sengsoulichanh, Phonexay; Mousquès, Claire; Soulileuth, Bounsamai; Pierret, Alain; Huon, Sylvain; Sengtaheuanghoung, Oloth

    2011-02-01

    Improving access to clean water has the potential to make a major contribution toward poverty reduction in rural communities of Lao P.D.R. This study focuses on stream water quality along a Mekong basin tributary, the Houay Xon that flows within a mountainous, mosaic land-use catchment of northern Lao P.D.R. To compare direct water quality measurements to the perception of water quality within the riparian population, our survey included interviews of villagers. Water quality was found to vary greatly depending on the location along the stream. Overall, it reflected the balance between the stream self-cleaning potential and human pressure on the riparian zone: (i) high bacteria and suspended load levels occurred where livestock are left to free-range within the riparian zone; (ii) very low oxygen content and high bacteriological contamination prevailed downstream from villages; (iii) high concentrations of bacteria were consistently observed along urbanized banks; (iv) low oxygen content were associated with the discharge of organic-rich wastewater from a small industrial plant; (v) very high suspended load and bacteria levels occurred during flood events due to soil erosion from steep cultivated hill slopes. Besides these human induced pollutions we also noted spontaneous enrichments in metals in wetland areas fed by dysoxic groundwater. These biophysical measurements were in agreement with the opinions expressed by the majority of the interviewees who reported poor and decreasing water quality in the Houay Xon catchment. Based on our survey, we propose recommendations to improve or maintain stream water quality in the uplands of northern Lao P.D.R.

  10. Using local ecological knowledge to monitor threatened Mekong megafauna in Lao PDR.

    Directory of Open Access Journals (Sweden)

    Thomas N E Gray

    Full Text Available Pressures on freshwater biodiversity in Southeast Asia are accelerating yet the status and conservation needs of many of the region's threatened fish species are unclear. This impacts the ability to implement conservation activities and to understand the effects of infrastructure developments and other hydrological changes. We used Local Ecological Knowledge from fishing communities on the Mekong River in the Siphandone waterscape, Lao PDR to estimate mean and mode last capture dates of eight rare or culturally significant fish species in order to provide conservation monitoring baselines. One hundred and twenty fishermen, from six villages, were interviewed. All eight species had been captured, by at least one of the interviewees, within the waterscape within the past year. However the mean and mode last capture dates varied between the species. Larger species, and those with higher Red List threat status, were caught less recently than smaller species of less conservation concern. The status of the Critically Endangered Pangasius sanitwongsei (mean last capture date 116.4 months is particularly worrying suggesting severe population decline although cultural issues may have caused this species to have been under-reported. This highlights that studies making use of Local Ecological Knowledge need to understand the cultural background and context from which data is collected. Nevertheless we recommend our approach, of stratified random interviews to establish mean last capture dates, may be an effective methodology for monitoring freshwater fish species of conservation concern within artisanal fisheries. If fishing effort remains relatively constant, or if changes in fishing effort are accounted for, differences over time in mean last capture dates are likely to represent changes in the status of species. We plan to repeat our interview surveys within the waterscape as part of a long-term fish-monitoring program.

  11. Vegetation and vascular flora of the Mekong River, Kratie and Steung Treng Provinces, Cambodia

    Directory of Open Access Journals (Sweden)

    James F. Maxwell

    2009-04-01

    Full Text Available A preliminary and detailed botanical survey of the islands in the Mekong River between Kratie and Steung Treng was done. This area includes the most biologically intact and threatened riparian and terrestrial ecosystems along the river in Cambodia. The vegetation includes six riverine zones and four terrestrial facies. Riverine habitats are mostly intact while the terrestrial vegetation ranges from destroyed to degraded. Effective conservation measures are required to stop further habitat destruction and loss of biodiversity. One new species, 23 records for the Cambodian flora, and a total of 690 species were collected. Detailed descriptions of all habitats, a database, and photographs are included. Increased exploitative human settlement in the area has caused drastic environmental changes with extensive deforestation and hunting. The forests are grazed, burned, logged, and often cleared for agricultural use without effective control. Sustainable management and scientifically acceptable development must be implemented before the area is totally ruined. Properly conceived reforestation is urgently required as well as a conservation education project aimed directly at the people living in the area. Unless effective restraints are implemented the area will become biologically destitute and will not be able to provide the natural resources that people require--in short, the area will become uninhabitable. Restoration of degraded or destroyed places will be impossible or far more difficult than conservation and intelligent management of presently endangered places. The potential for profitable eco-tourism should also be considered since tourists will certainly want to visit natural ecosystems on some of the islands. Only if local people are directly involved in eco-tourism and understand the necessity of conservation can this activity be successful. It is strongly recommended that continued botanical research be conducted in the area in order to

  12. The disappearing Environmental Kuznets Curve: a study of water quality in the Lower Mekong Basin (LMB).

    Science.gov (United States)

    Wong, Yoon Loong Andrew; Lewis, Lynne

    2013-12-15

    The literature is flush with articles focused on estimating the Environmental Kuznets Curve (EKC) for various pollutants and various locations. Most studies have utilized air pollution variables; far fewer have utilized water quality variables, all with mixed results. We suspect that mixed evidence of the EKC stems from model and error specification. We analyze annual data for four water quality indicators, three of them previously unstudied - total phosphorus (TOTP), dissolved oxygen (DO), ammonium (NH4) and nitrites (NO2) - from the Lower Mekong Basin region to determine whether an Environmental Kuznets Curve (EKC) is evident for a transboundary river in a developing country and whether that curve is dependent on model specification and/or pollutant. We build upon previous studies by correcting for the problems of heteroskedasticity, serial correlation and cross-sectional dependence. Unlike multi-country EKC studies, we mitigate for potential distortion from pooling data across geographically heterogeneous locations by analyzing data drawn from proximate locations within a specific international river basin in Southeast Asia. We also attempt to identify vital socioeconomic determinants of water pollution by including a broad list of explanatory variables alongside the income term. Finally, we attempt to shed light on the pollution-income relationship as it pertains to trans-boundary water pollution by examining data from an international river system. We do not find consistent evidence of an EKC for any of the 4 pollutant indicators in this study, but find the results are entirely dependent on model and error specification as well as pollutant. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Coping capacities for improving adaptation pathways for flood protection in Can Tho, Vietnam

    Science.gov (United States)

    Pathirana, A.; Radhakrishnan, M.; Quan, N. H.; Gersonius, B.; Ashley, R.; Zevenbergen, C.

    2016-12-01

    Studying the evolution of coping and adaptation capacities is a prerequisite for preparing an effective flood management plan for the future, especially in the dynamic and fast changing cities of developing countries. The objectives, requirements, targets, design and performance of flood protection measures will have to be determined after taking into account, or in conjunction with, the coping capacities. A methodology is presented based on adaptation pathways to account for coping capacities and to assess the effect on flood protection measures. The adaptation pathways method determines the point of failure of a particular strategy based on the change in an external driver, a point in time or a socio economic situation where / at which the strategy can no longer meet its objective. Pathways arrived at based on this methodology reflect future reality by considering changing engineering standards along with future uncertainties, risk taking abilities and adaptation capacities. This pathways based methodology determines the Adaptation tipping points (ATP), `time of occurrence of ATP' of flood protection measures after accounting for coping capacities, evaluates the measures and then provides the means to determine the adaptation pathways. Application of this methodology for flood protection measures in Can Tho city in the Mekong delta reveals the effect of coping capacity on the usefulness of flood protection measures and the delay in occurrence of tipping points. Consideration of coping capacity in the system owing to elevated property floor levels lead to the postponement of tipping points and improved the adaptation pathways comprising flood protection measures such as dikes. This information is useful to decision makers for planning and phasing of investments in flood protection.

  14. Hydrological and Climatic Significance of Martian Deltas

    Science.gov (United States)

    Di Achille, G.; Vaz, D. A.

    2017-10-01

    We a) review the geomorphology, sedimentology, and mineralogy of the martian deltas record and b) present the results of a quantitative study of the hydrology and sedimentology of martian deltas using modified version of terrestrial model Sedflux.

  15. Adaptive delta management : Roots and branches

    NARCIS (Netherlands)

    Timmermans, J.S.; Haasnoot, M.; Hermans, L.M.; Kwakkel, J.H.; Rutten, M.M.; Thissen, W.A.H.

    2015-01-01

    Deltas are generally recognized as vulnerable to climate change and therefore a salient topic in adaptation science. Deltas are also highly dynamic systems viewed from physical (erosion, sedimentation, subsidence), social (demographic), economic (trade), infrastructures (transport, energy,

  16. Adaptive Delta Management : Roots and Branches

    NARCIS (Netherlands)

    Timmermans, Jos; Haasnoot, Marjolijn; Hermans, Leon; Kwakkel, Jan H.; Rutten, Maarten; Thissen, Wil A.H.; Mynett, Arthur

    2015-01-01

    Deltas are generally recognized as vulnerable to climate change and therefore a salient topic in adaptation science. Deltas are also highly dynamic systems viewed from physical (erosion, sedimentation, subsidence), social (demographic), economic (trade), infrastructures (transport, energy,

  17. Delta Vegetation and Land Use [ds292

    Data.gov (United States)

    California Natural Resource Agency — Vegetation and land use are mapped for the approximately 725,000 acres constituting the Legal Delta portion of the Sacramento and San Joaquin River Delta area....

  18. Chinese State-Owned Enterprise Investment in Mekong Hydropower: Political and Economic Drivers and Their Implications across the Water, Energy, Food Nexus

    Directory of Open Access Journals (Sweden)

    Nathanial Matthews

    2015-11-01

    Full Text Available Over the last decade, Chinese State-Owned Enterprises have emerged as among the most active investors in Mekong Basin hydropower development. This paper uses a political economy analysis to examine the forces that drive Chinese State-Owned Enterprises to invest in hydropower in the Mekong Basin. We focus our analysis on the Lancang (Upper Mekong River in China and in the Greater Mekong Subregion (GMS, with an emphasis on Cambodia. The analysis reveals how powerful political and economic forces from within China and the GMS influence the pace, location and scale of investments in hydropower. These forces include foreign exchange reserves, trade packages and foreign direct investment, and political alliances. Combining the political economy and nexus approaches, we conclude that although policies from China recognize interconnections across the nexus, political and economic forces craft narratives that downplay or disregard these nexus interconnections and trade-offs. This in turn, influences how trade-offs and interconnections in hydropower development are managed and recognized in both local and transboundary contexts, thereby, creating potentially significant negative impacts on livelihoods, food security and the environment.

  19. Population Genetic Structure and Genetic Diversity in Twisted-Jaw Fish, Belodontichthys truncatus Kottelat & Ng, 1999 (Siluriformes: Siluridae, from Mekong Basin

    Directory of Open Access Journals (Sweden)

    Surapon Yodsiri

    2017-01-01

    Full Text Available The Mekong River and its tributaries possess the second highest diversity in fish species in the world. However, the fish biodiversity in this river is threatened by several human activities, such as hydropower plant construction. Understanding the genetic diversity and genetic structure of the species is important for natural resource management. Belodontichthys truncatus Kottelat & Ng is endemic to the Mekong River basin and is an important food source for people in this area. In this study, the genetic diversity, genetic structure, and demographic history of the twisted-jaw fish, B. truncatus, were investigated using mitochondrial cytochrome b gene sequences. A total of 124 fish specimens were collected from 10 locations in the Mekong and its tributaries. Relatively high genetic diversity was found in populations of B. truncatus compared to other catfish species in the Mekong River. The genetic structure analysis revealed that a population from the Chi River in Thailand was genetically significantly different from other populations, which is possibly due to the effect of genetic drift. Demographic history analysis indicated that B. truncatus has undergone recent demographic expansion dating back to the end of the Pleistocene glaciation.

  20. Delta Scuti variables. Lecture 6

    International Nuclear Information System (INIS)

    Cox, A.N.

    1983-01-01

    The class of variables near or on the upper main sequence, the delta Scuti variables, are not only the usual ones about the masses, radii, and luminosities, but also the age, rotation, element diffusion to change the surface layer composition, the occurance of convection and the presence of radial and nonradial pulsation modes

  1. about the Dirac Delta Function(?)

    Indian Academy of Sciences (India)

    V Balakrishnan is in the. Department of ... and sweet as befits this impatient age. It said (in its en- ... to get down to real work by shutting down the system and reverting to ... the Dirac delta function" - but do note the all-important question mark in ...

  2. Using Shoreline Video Assessment for coastal planning and restoration in the context of climate change in Kien Giang, Vietnam

    Science.gov (United States)

    Van Cuong, Chu; Russell, Michael; Brown, Sharon; Dart, Peter

    2015-06-01

    Kien Giang, bordering Cambodia in the Mekong River Delta, is one of the two most vulnerable provinces in the region to coastal erosion and flooding. Coastal protection can conflict with current land use and economic development activities. The conditions of the mangrove forest and mainland coastline of the Kien Giang province were assessed using the Shoreline Video Assessment Method (SVAM) backed up with information from satellite images. Half of the 206 km Kien Giang coastline has been eroded or is being eroded. Protective mangrove forests naturally occurred in 74% of the coastline but have been under threat from illegal cutting, erosion and coastal retreat. Accurate information on the state of the coastline and mangrove forest health provided invaluable data for developing a new coastal rehabilitation plan to guard against future sea level rise. In contrast to the current boundary management of land and natural resources, this plan divided the provincial coastline into 19 sections based on the landscape condition and exposure to erosion. Priority strategic actions for erosion management, mangrove restoration and sustainable livelihood development for local communities for each section of coast were developed based on an integrated cross sectoral approach and practical experience in the Conservation and Development of the Kien Giang Biosphere Reserve Project.

  3. Between system maker and privileges taker: the role of China in the Greater Mekong Sub-region

    Directory of Open Access Journals (Sweden)

    Truong-Minh Vu

    2014-01-01

    Full Text Available Utilizing China's leadership projects in the Great Mekong Sub-Region (GMS as a case study, this paper aims to investigate whether China qualifies as an international leader. This work argues that its geographic position and economic rise allow China to be a "system maker and privilege taker," which is a dual role forming in economic-political relations in the GMS in the last ten years. China is among major driving forces to set up an economic zone in GMS. Growing Chinese regional power is intimately related to the creation of various hubs connecting regional transportation, communication and energy systems that foster the economic development of this region. However, China also proves dark sides of rising powers which take advantage of their privileges to gain benefits. As a "system maker" with its own position and capability, China has notably benefited from building hydropower systems. More importantly, while China is pursuing its benefits and privileges, its hydropower projects have caused some negative effects for the ecosystem in the region. The inflation of dam constructions in both China and GMS countries is raising concerns about using natural resources of the Mekong River. Our concluding part addresses the pressing need to start a serious discussion on the balance between national interests and regional solidarity within the formulation of Chinese foreign policy in GMS.

  4. Simulating and predicting snow and glacier meltwater to the runoff of the Upper Mekong River basin in Southwest China

    Science.gov (United States)

    Han, Z.; Long, D.; Hong, Y.

    2017-12-01

    Snow and glacier meltwater in cryospheric regions replenishes groundwater and reservoir storage and is critical to water supply, hydropower development, agricultural irrigation, and ecological integrity. Accurate simulating and predicting snow and glacier meltwater is therefore fundamental to develop a better understanding of hydrological processes and water resource management for alpine basins and its lower reaches. The Upper Mekong River (or the Lancang River in China) as one of the most important transboundary rivers originating from the Tibetan Plateau (TP), features active dam construction and complicated water resources allocation of the stakeholders. Confronted by both climate change and significant human activities, it is imperative to examine contributions of snow and glacier meltwater to the total runoff and how it will change in the near future. This will greatly benefit hydropower development in the upper reach of the Mekong and better water resources allocation and management across the relevant countries. This study aims to improve snowfall and snow water equivalent (SWE) simulation using improved methods, and combines both modeling skill and remote sensing (i.e., passive microwave-based SWE, and satellite gravimetry-based total water storage) to quantify the contributions of snow and glacier meltwater there. In addition, the runoff of the Lancang River under a range of climate change scenarios is simulated using the improved modeling scheme to evaluate how climate change will impact hydropower development in the upper reaches.

  5. Magnetic minerals in three Asian rivers draining into the South China Sea: Pearl, Red, and Mekong Rivers

    Science.gov (United States)

    Kissel, Catherine; Liu, Zhifei; Li, Jinhua; Wandres, Camille

    2016-05-01

    The use of the marine sedimentary magnetic properties, as tracers for changes in precipitation rate and in oceanic water masses transport and exchanges, implies to identify and to characterize the different sources of the detrital fraction. This is of particular importance in closed and/or marginal seas such as the South China Sea. We report on the magnetic properties of sedimentary samples collected in three main Asian rivers draining into the South China Sea: the Pearl, Red, and Mekong Rivers. The geological formations as well as the present climatic conditions are different from one catchment to another. The entire set of performed magnetic analyses (low-field magnetic susceptibility, ARM acquisition and decay, IRM acquisition and decay, back-field acquisition, thermal demagnetization of three-axes IRM, hysteresis parameters, FORC diagrams, and low-temperature magnetic measurements) allow us to identify the magnetic mineralogy and the grain-size distribution when magnetite is dominant. Some degree of variability is observed in each basin, illustrating different parent rocks and degree of weathering. On average it appears that the Pearl River is rich in magnetite along the main stream while the Mekong River is rich in hematite. The Red River is a mixture of the two. Compared to clay mineral assemblages and major element contents previously determined on the same samples, these new findings indicate that the magnetic fraction brings complementary information of great interest for environmental reconstructions based on marine sediments from the South China Sea.

  6. Managing Tourism in the Greater Mekong Region (GMS: A Case Study of Chiang Khan Community, Northeast Thailand

    Directory of Open Access Journals (Sweden)

    Rawee Hanpachern

    2014-05-01

    Full Text Available This study aims to examine complex ‘sustainability’ aspects of the Community-based tourism concept in tourism and destination management in the Greater Mekong Sub-region (GMS. This research is conceptualized in assessing the potential for Community-Based Tourism (CBT development in Chiang Khan, a small village by the Mekong River in the Northeast of Thailand. For collecting data, semi-interviews questions are designed. Focus-group discussion and indepth interviews are carried to include tourism stakeholders of the destination. This study argues that although a community may contain many tourism assets, it is not the only factor necessary for a ‘sustainable’ tourism to be developed in that community. Through a case study, its natural features, cultural activities, local lifestyle and the serene landscape of its location are exemplified as the important community-based tourism assets. However, a number of complex components and holistic approaches that worked well together Chiang Khan becoming a sustainable tourism destination. There elements and approaches that contribute to starting up Chiang Khan as a sustainable tourist destination include: its unique features of recreational activities and local businesses, knowledge and skills of the locals to develop tourism related businesses, and direct proper marketing strategies.

  7. Water-Energy-Food Nexus in a Transboundary River Basin: The Case of Tonle Sap Lake, Mekong River Basin

    Directory of Open Access Journals (Sweden)

    Marko Keskinen

    2015-10-01

    Full Text Available The water-energy-food nexus is promoted as a new approach for research and policy-making. But what does the nexus mean in practice and what kinds of benefits does it bring? In this article we share our experiences with using a nexus approach in Cambodia’s Tonle Sap Lake area. We conclude that water, energy and food security are very closely linked, both in the Tonle Sap and in the transboundary Mekong River Basin generally. The current drive for large-scale hydropower threatens water and food security at both local and national scales. Hence, the nexus provides a relevant starting point for promoting sustainable development in the Mekong. We also identify and discuss two parallel dimensions for the nexus, with one focusing on research and analysis and the other on integrated planning and cross-sectoral collaboration. In our study, the nexus approach was particularly useful in facilitating collaboration and stakeholder engagement. This was because the nexus approach clearly defines the main themes included in the process, and at the same time widens the discussion from mere water resource management into the broader aspects of water, energy and food security.

  8. Variation in leaf water delta D and delta 18O values during the evapotranspiration process

    International Nuclear Information System (INIS)

    Leopoldo, P.R.; Foloni, L.L.

    1984-01-01

    A theoretical model was developed to evaluate leaf water delta D and delta 18 O variation in relation to: leaf temperature, relative humidity converted to leaf temperature and delta D and delta 18 O values of atmospheric water vapour and soil water. (M.A.C.) [pt

  9. Transgender at Work: Livelihoods for Transgender People in Vietnam

    NARCIS (Netherlands)

    Hoang, T.A.; Oosterhoff, P.

    2016-01-01

    The laws in the Socialist Republic of Vietnam promote equality for all citizens and refer to ‘persons’ rather than ‘men’ or ‘women’. However, because of traditional gender norms, transgender people in Vietnam are facing severe stigma and discrimination in public, in schools, at home and in the

  10. Emergence of Integrated Water Resources Management : Measuring implementation in Vietnam

    NARCIS (Netherlands)

    Akkerman, M.; Khanh, N.T.; Witter, M.; Rutten, M.M.

    2015-01-01

    Recently, the changes in laws and regulations, such as the revised Law on Water Resources in 2012, have sought to provide a legal framework for the internationally recognized practices of Integrated Water Resources Management (IWRM) in Vietnam. With IWRM being a novel approach for Vietnam, it would

  11. Vietnam : A Handwashing Behavior Change Journey for the Caretakers’ Program

    OpenAIRE

    World Bank

    2011-01-01

    The Vietnam Handwashing Initiative (HWI) was launched in January 2006 by the Ministry of Health (MoH) with funds from the Danish Embassy in Vietnam and technical assistance from the Water and Sanitation Program (WSP). This learning note documents the development process of the caretakers' program with a focus on how it was designed, implemented, and monitored. Lessons learned and challenge...

  12. State governance of pesticide use and trade in Vietnam

    NARCIS (Netherlands)

    Pham Van Hoi,; Mol, A.P.J.; Oosterveer, P.J.M.

    2013-01-01

    Vietnam is facing serious challenges with respect to the amount and toxicity of the pesticides used. With hardly any domestic pesticides production, Vietnam experienced an exponential growth of both the quantity and the value of imported pesticides in recent years. And the increasing import of newly

  13. The Making of "The Lessons of the Vietnam War."

    Science.gov (United States)

    Starr, Jerold M.

    1988-01-01

    Traces the development of "The Lessons of the Vietnam War," a set of units which cover legal, cultural, and historical questions of the war in greater depth than do survey textbooks. Examples of the 12 topics are "Introduction to Vietnam: Land, Culture, and History" and "Taking Sides: The War at Home." (GEA)

  14. Lessons for Hospital Autonomy : Implementation in Vietnam from International Experience

    OpenAIRE

    Vietnam Ministry of Health; Health Strategy and Policy Institute; World Bank; World Health Organization

    2011-01-01

    The Government of Vietnam sees hospital autonomy policy as important and consistent with current development trends in Vietnam. It is based on government policies as laid out in government Decree on financial autonomy of revenue-generating public service entities; and to 2006, it is replaced by decree on professional, organizational, human resource management and financial autonomy of reve...

  15. Primary English Language Education Policy in Vietnam: Insights from Implementation

    Science.gov (United States)

    Nguyen, Hoa Thi Mai

    2011-01-01

    The introduction of English in primary education curricula is a phenomenon occurring in many non-English-speaking countries in Asia, including Vietnam. Recently, the Ministry of Education and Training (MOET) in Vietnam issued guidelines for the piloting of an English as a foreign language (EFL) primary curriculum in which English is taught as a…

  16. Using Literature in a Course on the Vietnam War.

    Science.gov (United States)

    Goldstein, Jonathan

    1989-01-01

    Courses in Vietnam War history should incorporate Vietnamese, French, and English literary response to the war as complements to the history texts. Possibilities include an account of the French colonial experience, a required text in translation from the viewpoint of the Socialist Republic of Vietnam, and Vietnamese expatriate texts. (MSE)

  17. Health economics of screening for hypertension in Vietnam

    NARCIS (Netherlands)

    Nguyen, Thi Phuong Lan

    2016-01-01

    The studies aims to identify the burden of a cardiovascular diseases and solutions to manage it in Vietnam, notably hypertension screening. The studies confirmed that hypertension creates a great burden in Vietnam in terms of cardiovascular diseases, from economic, clinical and social perspectives.

  18. Teaching the New Vietnam: It's a Country, Not a War

    Science.gov (United States)

    McCornac, Dennis C.

    2008-01-01

    Vietnam has made remarkable progress over the past two decades in its transition to a market economy resulting in numerous changes to both its social and economic institutions. It is a nation at peace focusing on economic development and integrating into the world economy. Although the tragic events in Vietnam's history cannot be forgotten, the…

  19. Fostering Response to Vietnam War Literature through the Arts.

    Science.gov (United States)

    Johannessen, Larry R.

    1997-01-01

    Describes a unit on the literature of the Vietnam War (part of a college course called "Twentieth Century War Literature") which uses the arts to enhance student learning. Discusses activities and assignments in which students create visual representations, conduct research, and prepare oral reports on the Vietnam War literature they…

  20. 78 FR 7452 - Steel Wire Garment Hangers From Vietnam; Determinations

    Science.gov (United States)

    2013-02-01

    ...), that an industry in the United States is materially injured by reason of imports of steel wire garment... Garment Hangers From Vietnam; Determinations On the basis of the record \\1\\ developed in the subject... duty orders on steel wire garment hangers from Vietnam. Background The Commission instituted these...