WorldWideScience

Sample records for farming mekong valley

  1. 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 cost due to the

  2. 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

  3. Rice-freshwater prawn (Macrobrachium rosenbergii) farms in the Mekong Delta, Vietnam

    OpenAIRE

    Quang, Nguyen

    1993-01-01

    Aquaculture in riceland has been practiced in Mekong Delta, Vietnam for a long time and integrated rice-freshwater prawn (Macrobrachium rosenbergii) farming has become more and more popular. The integrated farming systems developed and practiced by farmers in the area to produce more food and more cash crops are presented and discussed.

  4. 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, wh

  5. 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 diff

  6. 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

  7. Monitoring rice farming activities in the Mekong Delta region

    Science.gov (United States)

    Nguyen, S. T.; Chen, C. F.; Chen, C. R.; Chiang, S. H.; Chang, L. Y.; Khin, L. V.

    2015-12-01

    Half of the world's population depends on rice for survival. Rice agriculture thus plays an important role in the developing world's economy. Vietnam is one of the largest rice producers and suppliers on earth and more than 80% of the exported rice was produced from the Mekong Delta region, which is situated in the southwestern Vietnam and encompasses approximately 40,000 km2. Changes in climate conditions could likely trigger the increase of insect populations and rice diseases, causing the potential loss of rice yields. Monitoring rice-farming activities through crop phenology detection can provide policymakers with timely strategies to mitigate possible impacts on the potential yield as well as rice grain exports to ensure food security for the region. The main objective of this study is to develop a logistic-based algorithm to investigate rice sowing and harvesting activities from the multi-temporal Moderate Resolution Imaging Spectroradiometer (MODIS)-Landsat fusion data. We processed the data for two main cropping seasons (i.e., winter-spring and summer-autumn seasons) through a three-step procedure: (1) MODIS-Landsat data fusion, (2) construction of the time-series enhanced vegetation index 2 (EVI2) data, (3) rice crop phenology detection. The EVI2 data derived from the fusion results between MODIS and Landsat data were compared with that of Landsat data indicated close correlation between the two datasets (R2 = 0.93). The time-series EVI2 data were processed using the double logistic method to detect the progress of sowing and harvesting activities in the region. The comparisons between the estimated sowing and harvesting dates and the field survey data revealed the root mean squared error (RMSE) values of 8.4 and 5.5 days for the winter-spring crop and 9.4 and 12.8 days for the summer-autumn crop, respectively. This study demonstrates the effectiveness of the double logistic-based algorithm for rice crop monitoring from temporal MODIS-Landsat fusion data

  8. Estimation of nitrogen and phosphorus in effluent from the striped catfish farming sector in the Mekong Delta, Vietnam.

    Science.gov (United States)

    De Silva, Sena S; Ingram, Brett A; Nguyen, Phuong T; Bui, Tam M; Gooley, Geoff J; Turchini, Giovanni M

    2010-11-01

    In this study an attempt is made to estimate nitrogen and phosphorus discharged to the environment from the striped catfish (Pangasianodon hypophthalmus) farming sector in the Mekong Delta (8 degrees 33'-10 degrees 55' N, 104 degrees 30'-106 degrees 50' E), South Vietnam. The sector accounted for 687,000 t production in 2007 and 1,094,879 t in 2008, with over 95% of the produce destined for export to over 100 countries. Commercial and farm-made feeds are used in catfish farming, currently the former being more predominant. Nitrogen discharge levels were similar for commercial feeds (median 46.0 kg/t fish) and farm-made feeds (median 46.8 kg/t fish); whilst, phosphorus discharge levels for commercial feeds (median 14.4 kg/t fish) were considerably lower than for farm-made feeds (median 18.4 kg/t fish). Based on the median nutrient discharge levels for commercial feeds, striped catfish production in the Mekong Delta discharged 31,602 t N and 9,893 t P, and 50,364 t N and 15,766 t P in 2007 and 2008, respectively. However, the amount of nutrients returned directly to the Mekong River may be substantially less than this as a significant proportion of the water used for catfish farming as well as the sludge is diverted to other agricultural farming systems. Striped catfish farming in the Mekong Delta compared favourably with other cultured species, irrespective of the type of feed used, when the total amounts of N and P discharged in the production of a tonne of production was estimated.

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

    OpenAIRE

    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 producing striped catfish. Additional to the LCA, we assessed water use and flooding hazards in the Mekong Delta. Materials and methods The goal and scope of the LCA were defined in a stakeholder ...

  10. 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 an

  11. 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

  12. 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

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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 levels

  15. A Decision Tree Analysis to Support Potential Climate Change Adaptations of Striped Catfish Farming in the Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    Nguyen, LA.

    2016-01-01

    Full Text Available 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 and secondary data. The latter studies showed that a proportion of the pangasius farms located in the coastal provinces will be affected by salinity intrusion in the dry season. Options to adapt to this are: modify pangasius farming practice, stock other species or stock saline-tolerant pangasius. With research and extension support, farmers can further improve their already adapted practice to deal with salinity or use water recirculation systems for prolonged nursery rearing. A breeding program for saline-tolerant striped catfish requires a medium-to long-term investment (0.4% of the production cost from government and/or private company. Pangasius farms in up- and mid-stream regions and in coastal areas, which are not located within upgraded government dyke-protected areas, will be affected by flooding at the end of each rainy season. This implies an increased cost for dykes to about 0.34% and 0.25% of the total variable costs for one harvest per ha in the up- and mid-stream regions, and in the downstream region, respectively.

  16. Simulated impacts of climate change on current farming locations of striped catfish (Pangasianodon hypophthalmus; Sauvage) in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Nguyen, Anh L; Dang, Vinh H; Bosma, Roel H; Verreth, Johan A J; Leemans, Rik; De Silva, Sena S

    2014-12-01

    In Vietnam, culturing striped catfish makes an important contribution to the Mekong Delta's economy. Water level rise during rainy season and salt intrusion during dry season affect the water exchange and quality for this culture. Sea level rise as a consequence of climate change will worsen these influences. In this study, water level rise and salt water intrusion for three sea level rise (SLR) scenarios (i.e., +30, +50, and +75 cm) were simulated. The results showed that at SLR +50, the 3-m-flood level would spread downstream and threaten farms located in AnGiang, DongThap and CanTho provinces. Rising salinity levels for SLR +75 would reduce the window appropriate for the culture in SocTrang and BenTre provinces, and in TienGiang's coastal districts. Next to increasing dikes to reduce the impacts, the most tenable and least disruptive option to the farming community would be to shift to a salinity tolerant strain of catfish.

  17. A New Species of Japalura (Squamata:Sauria:Agamidae) from Upper Lancang (Mekong) Valley of Eastern Tibet, China

    Institute of Scientific and Technical Information of China (English)

    Kai WANG; Ke JIANG; Gang PAN; Mian HOU; Cameron D SILER; Jing CHE

    2015-01-01

    A new species of the agamid genus Japalura is described based on 15 specimens from the upper Lancang (Mekong) Valley of eastern Tibet, PR China. Populations of the new species, Japalura vela sp. nov., were previously recognized as J. lfaviceps. The new species is morphologically most similar to J. batangensis, J. micangshanensis, J. variegata, and J. zhaoermii, but is distinguished from the four species and all remaining congeners by the following combination of morphological characters: 1) small adult size (SVL 56–69 mm in males, 59–66 mm in females); 2) ratio of tail TAL/SVL 1.85–2.06;3) ratio of hind limb HLL/SVL 0.72–0.81;4) T4S 24 or 25;5) concealed tympanum;6) transverse gular fold present;7) gular pouch present;8) axillary fold present;9) a pronounced, continuous, sail-like vertebral crest along length of body in males;10) ground dorsal coloration black in males;11) distinct gray transverse streaks on dorsal surface of head; 12) black radiated streaks around eyes; 13) distinct, black vermiculate stripes on ventral surface of head in both sexes;14) a strongly jagged dorsolateral stripe from neck to base of tail on each side of vertebral crest in males;and 15) absence of gular spots in both sexes. General distribution patterns of the genus in the Hengduan Mountains region are also discussed.

  18. Rudolf Steiner Farm School, Hawthorne Valley.

    Science.gov (United States)

    Rudolf Steiner Farm School, Harlemville, Ghent, NY.

    The goal of the Rudolf Steiner Farm School (which employs the spiritual/scientific path of knowledge described by Rudolf Steiner in the early 1900's) is to awaken and cultivate the capacities of the full human being through education, the arts, and agriculture, in direct relationship with nature, the spiritual universe, and current times. The…

  19. Farm Process (FMP) Parameters used in the Central Valley Hydrologic Model (CVHM)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset defines the farm-process parameters used in the transient hydrologic model of the Central Valley flow system. The Central Valley encompasses an...

  20. Soil salinity and sodicity in a shrimp farming coastal area of the Mekong Delta, Vietnam

    Science.gov (United States)

    Tho, Nguyen; Vromant, N.; Hung, Nguyen Thanh; Hens, L.

    2008-06-01

    Soil salinity and sodicity are environmental problems in the shrimp farming areas of the Cai Nuoc district, Ca Mau province, Vietnam. In 2000, farmers in the district switched en masse from rice cropping to shrimp culture. Due to recent failure in shrimp farming, many farmers wish to revert to a rotational system with rice in the wet season and shrimps in the dry season. So far, all their attempts to grow rice have failed. To assess soil salinity and sodicity, 25 boreholes in shrimp ponds were analysed in four consecutive seasons from 2002 to 2004. The results showed that soil salinity was quite serious (mean ECe 29.25 dS m-1), particularly in the dry season (mean ECe 33.44 dS m-1). In the wet season, significant amounts of salts still remained in the soil (mean ECe 24.65 dS m-1) and the highest soil salinity levels were found near the sea. Soil sodicity is also a problem in the district (exchangeable sodium percentage range 9.63-72.07%). Sodicity is mainly a phenomenon of topsoils and of soils near the sea. Both soil salinity and sodicity are regulated by seasonal rainfall patterns. They could together result in disastrous soil degradation in the Cai Nuoc district.

  1. Impacts of changes in mangrove forest management practices on forest accessibility and livelihood: A case study in mangrove-shrimp farming system in Ca Mau Province, Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Ha, T.T.P.; Dijk, van J.W.M.; Visser, L.E.

    2014-01-01

    This paper documents how the implementation of forest tenure policy affects the decision-making of farmers in mangrove-shrimp farming systems with regard to their access to and management of mangrove forest in Ca Mau, Mekong Delta, which is the largest remaining mangrove forest in Vietnam. Policies

  2. Simulated Impacts of Climate Change on Current Farming Locations of Striped Catfish (Pangasianodon hypophthalmus; Sauvage) in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

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

    2014-01-01

    In Vietnam, culturing striped catfish makes an important contribution to the Mekong Delta's economy. Water level rise during rainy season and salt intrusion during dry season affect the water exchange and quality for this culture. Sea level rise as a consequence of climate change will worsen these i

  3. 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

  4. The influence of changes in the market environment on economic production characteristics of Pangasius farming in the Mekong Delta (Vietnam)

    OpenAIRE

    Tu, V.B.; D'Haese, M.; Speelman, S.; D'Haese, 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 adaptability of the sector. We are particularly interested in the effect of the changing market environment and the exponential growth of the sector on the evolution of production characteristics. ...

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

    Directory of Open Access Journals (Sweden)

    Van Kien Nguyen

    2015-09-01

    Full Text Available 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 floating rice-sweet corn- two baby corn crops and cattle systems (VND 18.5 mil./1000m2, and floating rice-chili (VND 16.7-17.7 mil./1000m2. If farmers cultivate monoculture of rice either two or three crops, the net benefits are ranging from VND 2.2-4.8 mil./1000m2 respectively. Alternatively, farmers integrate vegetables; the net benefit was ranging from VND 5.6 to 11.7 mil./1000m2. The net benefit of the two rice crops is lowest (VND 1.3-2.3 mil./1000m2. Surprisingly, if farmers convert from two intensive rice crops to two maize crops, the net benefit can reach to VND 21 million/1000m2. The results support the argument that the floating rice based systems allows farmers diversified into profitable upland crops, which can help farmers to improve their total income.

  6. 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

  7. What Factors Encourage Intrafamily Farm Succession in Mountain Areas? Evidence From an Alpine Valley in Italy

    Directory of Open Access Journals (Sweden)

    Daniele Cavicchioli

    2015-05-01

    Full Text Available Family farming plays a vital role in mountain areas. Its survival is related to multiple factors, including intrafamily farm succession. This study examined data on apple-producing family farms in an Italian Alpine valley, trying to identify which factors foster or discourage intrafamily succession and to what extent they do this, both at the farm level and from the potential successor's viewpoint. To do so, various farm, farmer, and individual characteristics were analyzed using probabilistic regression. We found that intrafamily succession was more likely when the farm was managed by a woman (+20% with a high school diploma (+13% who had at least 1 child with specialized education in agriculture (+27% and when farm sales had increased in recent years (+25%. We also found that a child's willingness to take over the family farm decreases as the number of farm children increases and when the child is a female with a high school diploma; however, the likelihood that children will take over the family business rises as farmer education level and work experience increase. These findings, while mixed, suggest that women play a key role in keeping family farming alive in mountain areas, along with education of family members, improved marketability of agricultural products, and in general, competitiveness and profitability of the family farm.

  8. 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

  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 s

  10. Business plan Tilapia Pond Farming in the Zambezi Valley, Mozambique

    NARCIS (Netherlands)

    Brouwer, Herman; Meer, van der Magnus

    2015-01-01

    This business plan has been prepared for local entrepreneurs who would like to expand their business portfolio or to start a value chain business in the aquaculture sector in the Zambezi Valley, Mozambique.

    Freshwater aquaculture in Mozambique consists mainly of small-scale tilapia producti

  11. Business plan Tilapia cage farming in Tete Zambezi Valley, Mozambique

    NARCIS (Netherlands)

    Meer, van der Magnus; Brouwer, Herman

    2015-01-01

    Tete province offers great opportunities for cage farming of tilapia in Lake Cahora Bassa. The climate and water quality are favourable for fish production, and the fast economic developments in the region will facilitate fish sales. In Tete tilapia (pende) is highly valued food. Major markets for t

  12. A bio-economic farm household model to assess cropping systems in the Rift valley of Ethiopia : towards climate smart agriculture: do food security and mitigration goals match?

    NARCIS (Netherlands)

    Hengsdijk, H.; Verhagen, A.

    2012-01-01

    Modelling approach for rain fed farm household systems in the Central Rif Valley of Ethiopia to assess the possible effects of intensification of cereal-based cropping systems to farm income, mitigation of GHG emissions and other household indicators

  13. 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,

  14. 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, h

  15. [Beta-hexachlorocyclohexane contamination in dairy farms of the Sacco River Valley, Latium, Italy, 2005. A retrospective cohort study].

    Science.gov (United States)

    Sala, Marcello; Caminiti, Antonino; Rombolà, Pasquale; Volpe, Aldo; Roffi, Cristina; Caperna, Osvaldo; Miceli, Maria; Ubaldi, Alessandro; Battisti, Antonio; Scaramozzino, Paola

    2012-01-01

    in March 2005, the Italian National Monitoring System on Chemical Residuals in Food of Animal Origin detected levels of the pesticide beta-hexachlorocyclohexane (ß-HCH) that were 20 times higher than the legal limit of 0.003 mg/kg in bulk milk from a dairy farm in the Sacco River valley. ß-HCH, a lindane isomer and possible human carcinogen, was subsequently found in milk from several neighboring farms. A study was therefore undertaken to evaluate the extent and risk factors for contamination. all dairy cattle farms in the valley were enrolled in a retrospective cohort study and their bulk milk analyzed for ß-HCH. A questionnaire was administered to farmers to evaluate possible exposure factors. cases: dairy farms with at least one result indicating ß-HCH ≥ 0.002 mg/kg in bulk milk during the period april-june 2005; exposure: feeding animals on fodder cultivated in soils watered with and/or flooded by river water; participants: IZSLT, RMG Local Health Unit, FR Local Health Unit. attack rate, relative risk, attributable proportion among exposed. of 244 farms tested, 34 met the case definition (attack rate 14%). The exposure to fodder cultivated in soils watered with and/or flooded by river water was observed in 33/34 (97%) case-farms and in 23/210 (10.9%) of those with contamination milk (RR 110.8; 95%CI 15.5- 792). Attributable proportion among exposed was more than 99%. fodder cultivated near a contaminated river was the main risk factor for ß-HCH contaminated milk. On the basis of the epidemiologic evidence and laboratory testing, watering local fields with river water and production of fodder in farms with contaminated soil was banned, and all the animals from positive farms were culled.

  16. THE ROLE OF THE MALARIA VECTORS IN THE UPPER VALLEY OF MEKONG RIVER IN YUNNAN%云南湄公河流域上游河谷地区疟疾媒介传疟作用研究

    Institute of Scientific and Technical Information of China (English)

    周红宁; 张再兴; 李春富; 吴超; 王丕玉; Chris; Curtis; Nigel; Hill

    2005-01-01

    Objective To study the role of the malaria vectors in the upper valley of Mekong River in Yunnan by studying their seasonal abundance, host preference, biting behaviors and sporozites rates. Methods Mosquitoes were collected by light-traps and human landing catches in villages;sporozoites were detected in the salivary glands under microscopy in the field sites and circumsporozoite proteins (CSP) from mosquito was tested by ELISA. Results A total of 16 Anopheles species were caught in villages. 7 sporozoite positive mosquitoes in the salivary glands were found from 1 010 parous mosquitoes in 7 Anopheles species in the fields;CSP were detected positive in 11 mosquitoes by ELISA out of 5 154 mosquitoes in 8 Anopheles species. sporozoites rate was 0.37%, 0.22% and 0.32% in Anopheles minimus, An. sinensis and An. maculatus respectively (including CSP positive by ELISA and sporozoite positive in the salivary glands), and their entomological inoculation rate was estimated to be 9.82, 3.97 and 2.69 respectively. The biting activity began after dusk and was maintained through the night, but feeding peak of the An. minimus was in the midnight, and that of An. sinensis and An. maculatus occurred before 21:00. The human blood index was over 80% for all 3 mosquitoes. Conclusion It is suggested that An. minimus, An. sinensis and An. maculatus are the most important malaria vectors in the upper valley of Mekong River.%目的通过观察蚊媒季节消长、嗜血习性、叮咬行为和疟疾子孢子率以研究出它们在云南湄公河上游河谷地带传疟作用的关系. 方法村内采取诱蚊灯和人工诱捕方法捕蚊;现场采取显微镜解剖蚊虫的方法观察唾腺子孢子,实验室采用ELISA技术检测蚊虫体内环子孢子蛋白(CSP). 结果村内共捕获16种按蚊.现场显微镜解剖7种按蚊,1 010只经产蚊中,发现了7只唾液腺感染子孢子;ELISA方法检测现场捕回的8种按蚊,5 154只各龄期蚊中,发现11只环子孢子蛋

  17. Education Outreach Associated with Technology Transfer in a Colonia of South Texas: Green Valley Farms Science and Space Club for Middle School Aged Children in Green Valley Farms, San Benito, Texas

    Science.gov (United States)

    Potess, Marla D.; Rainwater, Ken; Muirhead, Dean

    2004-01-01

    Texas colonias are unincorporated subdivisions characterized by inadequate water and wastewater infrastructure, inadequate drainage and road infrastructure, substandard housing, and poverty. Since 1989 the Texas Legislature has implemented policies to halt further development of colonias and to address water and wastewater infrastructure needs in existing and new colonias along the border with Mexico. Government programs and non-government and private organization projects aim to address these infrastructure needs. Texas Tech University's Water Resources Center demonstrated the use of alternative on-site wastewater treatment in the Green Valley Farms colonia, San Benito, Texas. The work in Green Valley Farms was a component of a NASA-funded project entitled Evaluation of NASA's Advanced Life Support Integrated Water Recovery System for Non-Optimal Conditions and Terrestrial Applications. Two households within the colonia are demonstration sites for constructed wetlands. A colonia resident and activist identified educational opportunities for colonia children as a primary goal for many colonia residents. Colonia parents view education as the door to opportunity and escape from poverty for their children. The educational outreach component of the project in Green Valley Farms was a Science and Space Club for middle-school age students. Involved parents, schoolteachers, and school administrators enthusiastically supported the monthly club meetings and activities. Each month, students participated in interactive learning experiences about water use and reuse in space and on earth. Activities increased knowledge and interest in water resource issues and in science and engineering fields. The Institute for the Development and Enrichment of Advanced Learners (IDEAL) at Texas Tech University provided full scholarships for five students from Green Valley Farms to attend the Shake Hands With Your Future camp at Texas Tech University in June 2003. The educational outreach

  18. Education Outreach Associated with Technology Transfer in a Colonia of South Texas: Green Valley Farms Science and Space Club for Middle School Aged Children in Green Valley Farms, San Benito, Texas

    Science.gov (United States)

    Potess, Marla D.; Rainwater, Ken; Muirhead, Dean

    2004-01-01

    Texas colonias are unincorporated subdivisions characterized by inadequate water and wastewater infrastructure, inadequate drainage and road infrastructure, substandard housing, and poverty. Since 1989 the Texas Legislature has implemented policies to halt further development of colonias and to address water and wastewater infrastructure needs in existing and new colonias along the border with Mexico. Government programs and non-government and private organization projects aim to address these infrastructure needs. Texas Tech University's Water Resources Center demonstrated the use of alternative on-site wastewater treatment in the Green Valley Farms colonia, San Benito, Texas. The work in Green Valley Farms was a component of a NASA-funded project entitled Evaluation of NASA's Advanced Life Support Integrated Water Recovery System for Non-Optimal Conditions and Terrestrial Applications. Two households within the colonia are demonstration sites for constructed wetlands. A colonia resident and activist identified educational opportunities for colonia children as a primary goal for many colonia residents. Colonia parents view education as the door to opportunity and escape from poverty for their children. The educational outreach component of the project in Green Valley Farms was a Science and Space Club for middle-school age students. Involved parents, schoolteachers, and school administrators enthusiastically supported the monthly club meetings and activities. Each month, students participated in interactive learning experiences about water use and reuse in space and on earth. Activities increased knowledge and interest in water resource issues and in science and engineering fields. The Institute for the Development and Enrichment of Advanced Learners (IDEAL) at Texas Tech University provided full scholarships for five students from Green Valley Farms to attend the Shake Hands With Your Future camp at Texas Tech University in June 2003. The educational outreach

  19. Life cycle assessment of food production in integrated agriculture–aquaculture systems of the Mekong Delta

    NARCIS (Netherlands)

    Phong, L.T.; Boer, de I.J.M.; Udo, H.M.J.

    2011-01-01

    This study evaluated the environmental impact of integrated agriculture–aquaculture (IAA) farming systems in the Mekong Delta that differ in types of aquaculture intensification. Daily inputs and outputs for rice, fruits, vegetables, pigs, poultry, and fish were collected on 11 farms over a period o

  20. Integrated Geophysical Investigation of Preferential Flow Paths at the Former Tyson Valley Powder Farm near Eureka, Missouri, May 2006

    Science.gov (United States)

    Burton, Bethany L.; Ball, Lyndsay B.; Stanton, Gregory P.; Hobza, Christopher M.

    2009-01-01

    In May 2006, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, conducted surface and borehole geophysical surveys at the former Tyson Valley Powder Farm near Eureka, Mo., to identify preferential pathways for potential contaminant transport along the bedrock surface and into dissolution-enhanced fractures. The Tyson Valley Powder Farm was formerly used as a munitions storage and disposal facility in the 1940s and 1950s, and the site at which the surveys were performed was a disposal area for munitions and waste solvents such as trichloroethylene and dichloroethylene. Direct-current resistivity and seismic refraction data were acquired on the surface; gamma, electromagnetic induction, and full waveform sonic logs were acquired in accessible boreholes. Through the combined interpretation of the seismic refraction tomographic and resistivity inversion results and borehole logs, inconsistencies in the bedrock surface were identified that may provide horizontal preferential flow paths for dense nonaqueous phase liquid contaminants. These results, interpreted and displayed in georeferenced three-dimensional space, should help to establish more effective monitoring and remediation strategies.

  1. Adapting to Climate Variability and Change: Experiences from Cereal-Based Farming in the Central Rift and Kobo Valleys, Ethiopia

    Science.gov (United States)

    Kassie, Belay Tseganeh; Hengsdijk, Huib; Rötter, Reimund; Kahiluoto, Helena; Asseng, Senthold; Van Ittersum, Martin

    2013-11-01

    Small-holder farmers in Ethiopia are facing several climate related hazards, in particular highly variable rainfall with severe droughts which can have devastating effects on their livelihoods. Projected changes in climate are expected to aggravate the existing challenges. This study examines farmer perceptions on current climate variability and long-term changes, current adaptive strategies, and potential barriers for successful further adaptation in two case study regions—the Central Rift Valley (CRV) and Kobo Valley. The study was based on a household questionnaire, interviews with key stakeholders, and focus group discussions. The result revealed that about 99 % of the respondents at the CRV and 96 % at the Kobo Valley perceived an increase in temperature and 94 % at CRV and 91 % at the Kobo Valley perceived a decrease in rainfall over the last 20-30 years. Inter-annual and intraseasonal rainfall variability also has increased according to the farmers. The observed climate data (1977-2009) also showed an increasing trend in temperature and high inter-annual and intra-seasonal rainfall variability. In contrast to farmers’ perceptions of a decrease in rainfall totals, observed rainfall data showed no statistically significant decline. The interaction among various bio-physical and socio-economic factors, changes in rainfall intensity and reduced water available to crops due to increased hot spells, may have influenced the perception of farmers with respect to rainfall trends. In recent decades, farmers in both the CRV and Kobo have changed farming practices to adapt to perceived climate change and variability, for example, through crop and variety choice, adjustment of cropping calendar, and in situ moisture conservation. These relatively low-cost changes in farm practices were within the limited adaptation capacity of farmers, which may be insufficient to deal with the impacts of future climate change. Anticipated climate change is expected to impose new

  2. Adapting to climate variability and change: experiences from cereal-based farming in the central rift and Kobo Valleys, Ethiopia.

    Science.gov (United States)

    Kassie, Belay Tseganeh; Hengsdijk, Huib; Rötter, Reimund; Kahiluoto, Helena; Asseng, Senthold; Van Ittersum, Martin

    2013-11-01

    Small-holder farmers in Ethiopia are facing several climate related hazards, in particular highly variable rainfall with severe droughts which can have devastating effects on their livelihoods. Projected changes in climate are expected to aggravate the existing challenges. This study examines farmer perceptions on current climate variability and long-term changes, current adaptive strategies, and potential barriers for successful further adaptation in two case study regions-the Central Rift Valley (CRV) and Kobo Valley. The study was based on a household questionnaire, interviews with key stakeholders, and focus group discussions. The result revealed that about 99 % of the respondents at the CRV and 96 % at the Kobo Valley perceived an increase in temperature and 94 % at CRV and 91 % at the Kobo Valley perceived a decrease in rainfall over the last 20-30 years. Inter-annual and intraseasonal rainfall variability also has increased according to the farmers. The observed climate data (1977-2009) also showed an increasing trend in temperature and high inter-annual and intra-seasonal rainfall variability. In contrast to farmers' perceptions of a decrease in rainfall totals, observed rainfall data showed no statistically significant decline. The interaction among various bio-physical and socio-economic factors, changes in rainfall intensity and reduced water available to crops due to increased hot spells, may have influenced the perception of farmers with respect to rainfall trends. In recent decades, farmers in both the CRV and Kobo have changed farming practices to adapt to perceived climate change and variability, for example, through crop and variety choice, adjustment of cropping calendar, and in situ moisture conservation. These relatively low-cost changes in farm practices were within the limited adaptation capacity of farmers, which may be insufficient to deal with the impacts of future climate change. Anticipated climate change is expected to impose new

  3. Water and nutrient budgets of ponds in integrated agriculture-aquaculture systems in the Mekong Delta, Vietnam.

    NARCIS (Netherlands)

    Nhan, D.K.; Verdegem, M.C.J.; Milstein, A.; Verreth, J.A.J.

    2008-01-01

    A participatory on-farm study analysed water and nutrient budgets of six low and four high water-exchange ponds of integrated agriculture-aquaculture (IAA) farms in the Mekong delta. Water, nitrogen (N), organic carbon (OC) and phosphorus (P) flows through the ponds were monitored, and data on fish

  4. Using fuzzy logic modelling to simulate farmers’ decision-making on diversification and integration in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Bsma, R.; Kaymak, U.; Van den Berg, J.; Udo, H.

    2010-01-01

    To reveal farmers’ motives for on-farm diversification and integration of farming components in the Mekong Delta, Vietnam, we developed a fuzzy logic model (FLM) using a 10-step approach. Farmers’ decision-making was mimicked in a three-layer hierarchical architecture of fuzzy inference systems, usi

  5. Using fuzzy logic modelling to simulate farmers' decision-making on diversification and integration in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Bosma, R.H.; Kaymak, U.; Berg, van den J.; Udo, H.M.J.; Verreth, J.A.J.

    2011-01-01

    To reveal farmers’ motives for on-farm diversification and integration of farming components in the Mekong Delta, Vietnam, we developed a fuzzy logic model (FLM) using a 10-step approach. Farmers’ decision-making was mimicked in a three-layer hierarchical architecture of fuzzy inference systems, usi

  6. Water pollution by Pangasius production in the Mekong Delta, Vietnam: causes and options for control

    NARCIS (Netherlands)

    Pham Thi Ahn,; Kroeze, C.; Bush, S.R.; Mol, A.P.J.

    2010-01-01

    In this paper, we analyse water pollution caused by farming and processing Pangasianodon hypophthalmus in the Mekong Delta of Vietnam. The results show that 1 tonne of frozen fillets releases 740 kg BOD, 1020 kg COD, 2050 kg TSS, 106 kg nitrogen and 27 kg phosphorus, of which wastewater from fish po

  7. THE BIOLOGY AND BEHAVIOUR OF JAPANESE ENCEPHALITIS VECTORS IN THE HUMAN HOUSES IN THE UPPER VALLEY OF THE MEKONG RIVER IN YUNNAN, P.R. CHINA%中国云南湄公河上游乙型脑炎传播媒介生物学及行为的研究

    Institute of Scientific and Technical Information of China (English)

    周红宁; 李春富; 吴超; 张再兴; 王丕玉; Nigel Hill

    2005-01-01

    Objective To study the seasonal abundance, host preference and patterns of biting activity in houses, and larval biology of Japanese Encephalitis(JE) vectors, so as to develop effective control measures. Methods From June to December 2001, choosing one plantation in the upper valley of the Mekong River in the south of Yunnan, Centres for Disease Control (CDC) light-trap and human landing methods were used to capture mosquitoes, blood meal samples were tested by the precipitin method and biologic habits of immature stages were investigated for their breeding sites. Results A total of 5 726 JE vector mosquitoes of 11 species of 5 genera were collected from a plantation in the upper valley of the Mekong River. Peaks in the population densities of Culex tritaeniorhynchus, Cx. pseudovishnui, Cx. fuscocephala and Anopheles sinensis were in the rainy season from June to August, by both light-trap and human landing catches. Biting activity of these three Culex mosquitoes, both in and outside plantation, began after sunset and maintained through the night. But the An. sinensis biting peak was before 21:00 hours. Comparison of the efficacy of mosquito collection by light trap in houses with that out of doors by human landing catches, showed that the indoor catches of JE vectors were higher than that out of doors. Analysis of mosquito blood meals showed that their human blood indices were high. Larvae had characteristic distributions in relation to the plantation. Conclusion All of these finds suggested that in the upper valley of Mekong River, Cx. tritaeniorhynchus, Cx. pseudovishnui, Cx. fuscocephala and An. sinensis are different on the biologics and behaviours in comparison with those of previous studies in animal sheds.%目的探讨乙型脑炎病毒媒介在人房的季节消长、嗜血习性和叮人行为,以及其幼虫相关的生物学习性, 从而制定出有效的媒介控制措施. 方法 2001年6~12月,在云南南部湄公河上游,选

  8. Determinants of field edge habitat restoration on farms in California's Sacramento Valley.

    Science.gov (United States)

    Garbach, Kelly; Long, Rachael Freeman

    2017-03-15

    Degradation and loss of biodiversity and ecosystem services pose major challenges in simplified agricultural landscapes. Consequently, best management practices to create or restore habitat areas on field edges and other marginal areas have received a great deal of recent attention and policy support. Despite this, remarkably little is known about how landholders (farmers and landowners) learn about field edge management practices and which factors facilitate, or hinder, adoption of field edge plantings. We surveyed 109 landholders in California's Sacramento Valley to determine drivers of adoption of field edge plantings. The results show the important influence of landholders' communication networks, which included two key roles: agencies that provide technical support and fellow landholders. The networks of landholders that adopted field edge plantings included both fellow landholders and agencies, whereas networks of non-adopters included either landholders or agencies. This pattern documents that social learning through peer-to-peer information exchange can serve as a complementary and reinforcing pathway with technical learning that is stimulated by traditional outreach and extension programs. Landholder experience with benefits and concerns associated with field edge plantings were also significant predictors of adoption. Our results suggest that technical learning, stimulated by outreach and extension, may provide critical and necessary support for broad-scale adoption of field-edge plantings, but that this alone may not be sufficient. Instead, outreach and extension efforts may need to be strategically expanded to incorporate peer-to-peer communication, which can provide critical information on benefits and concerns.

  9. 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.

  10. A participatory modelling approach to define farm-scale effects of reclaimed wastewater irrigation in the Lockyer Valley, Australia

    NARCIS (Netherlands)

    Opstal, van J.D.; Huibers, F.P.; Cresswell, R.G.

    2012-01-01

    The Lockyer Valley is an important agricultural area experiencing water insecurity, which causes a decrease in agricultural production. Regional authorities are initiating a wastewater reclamation project conveying treated municipal wastewater to water users, including potentially the Lockyer Valley

  11. Herd- and individual-level prevalences of and risk factors for Salmonella spp. fecal shedding in dairy farms in Al-Dhulail Valley, Jordan.

    Science.gov (United States)

    Tarazi, Yaser H; Abo-Shehada, Mahmoud N

    2015-10-01

    Salmonellosis is an important disease frequently associated with diarrhea in calves. From January to September 2009, a cross-sectional study involving 91 dairy farms was conducted to determine the prevalence of Salmonella spp. infection in cattle in Al-Dhulail Valley, Jordan. A total of 910 calve and cow fecal samples were collected. Information on farm management practices was obtained through personal interviews using a standardized questionnaire and was tested as risk factors for Salmonella spp. positivity in farms by using logistic regression analysis. Standard conventional methods for Salmonella isolation and serotyping were used, and the disk agar diffusion test was used for antimicrobial testing. The herd-level prevalence of Salmonella spp. in calves, cows, and dairy farms was 12, 12, and 23 %, respectively, and the individual-level prevalence was 4 % for calves, cows, and dairy farms. Forty-six percent of the dairy farms had calf diarrhea, and 4 % had cow diarrhea. Seven (17 %) of the 42 farms with calf diarrhea had Salmonella. However, only 7 % (95 % CI: 4, 10) of the 221 diarrheic and 1 % (95 % CI: 0.2, 4) of the 234 of non-diarrheic calves had Salmonella. A total of 33 Salmonella isolates were obtained from the fecal samples: 12 isolates were Salmonella typhimurium, 6 were Salmonella montevideo, 6 were Salmonella anatum, 2 were Salmonella enteritidis, and 7 isolates were not serotyped. All isolates were susceptible to ciprofloxacin, trimethoprim-sulfamethoxazole, gentamycin, neomycin, colisitin, and amoxicillin at 100, 91, 85, 79, 79, and 70 %, respectively. Out of the 11 variables/categories, the frequency of cleaning every 2 months or more was associated with high odds of infection among calves (OR = 5.6) and farms (OR = 7.0).

  12. Physico-chemical qualities of water in high altitude rice fish farming system of Ziro valley, Arunachal Pradesh, India.

    Science.gov (United States)

    Saikia, Rajashree; Das, Tapati; Das, Debangshu Narayan

    2015-09-01

    Water in rice fields of mountain valley of Ziro, Arunachal Pradesh was investigated for physico-chemical characterization during rice fish farming season (Kharif) of 2013. Water temperature, dissolved oxygen, biological oxygen demand, free carbon dioxide, nitrate-nitrogen, phosphate-phosphorus, chloride, total hardness, calcium hardness, alkalinity, pH, total dissolved solids, specific conductivity and water depth were studied. This study revealed that the physical parameters of water in rice fields like water temperature, pH, total dissolved solids, specific conductivity and water depth were 23.5-31.3 degrees C, 5.9-6.9, 250.34-370.5 mgl(-1), 437.75-660.33 μScm(-1) and 3.72-16.9 cm respectively. The chemical features like dissolved oxygen, biological oxygen demand, free CO2, nitrate-nitrogen, phosphate-phosphorus, chloride, total hardness Ca hardness, alkalinity were 2.4-12.9 mgl(-1), 1.5-11.1 mgl(-1), 9.7-23.35 mgl(-1), 1.28-3.9 mgl(-1), 0.005-0.539 mgl(-1), 16.6-46.8 mgl(-1), 13.9-34.5 mgl(-1), 9.6-13.53 mgl(-1) and 23.16-43.34 mgl(-1) respectively. On the other hand, investigation on planktonic life forms indicated the presence of 13.5x10(3)-84.9x10(3) indl(-1)" and 1.23x10(3)-4.86x10(3) indl(-1) phytoplankton and zooplankton respectively during the Kharif season. The above physiochemical parameters were found to be conducive for raising fish as companion crop of rice due to occurrence of diversified planktonic life forms in underneath water.

  13. Silvicultural management and land characteristics affecting the growth of rhizopora apiculata in Thanh Phu, Ben Tre Province, Mekong delta, Vietnam

    NARCIS (Netherlands)

    Mensvoort, van M.E.F.; McKenzie, P.

    2002-01-01

    During the Indo-China war an estimated 200,000 ha of Vietnamese mangrove forests were destroyed by chemical warfare. Since the war clearance for aquaculture and population pressure caused further deforestation, particularly in the Mekong delta. Mangrove reforestation is desired. At the state farm at

  14. An investigation into an outbreak of Rift Valley fever on a cattle farm in Bela-Bela, South Africa, in 2008

    Directory of Open Access Journals (Sweden)

    Lourenço P. Mapaco

    2012-10-01

    Full Text Available In 2008, a suspected outbreak of Rift Valley fever (RVF was reported on a farm in the Bela-Bela area, Limpopo Province, South Africa. Seven calves died on the affected dairy farm, where no RVF vaccination programme was practised. No apparent clinical disease was reported in the other 300 cattle (33 calves included or 200 sheep on the farm. During the outbreak, blood samples from 77.7% (233/300 of the cattle and 36.5% (73/200 of the sheep were collected on the affected farm and 55 blood samples were taken from cattle on a neighbouring farm. Eight weeks later, 78% of the cattle (234/300 and 42.5% of the sheep (85/200 were bled on the affected farm only. All sera were tested by an Immunoglobulin M (IgM-capture Enzymelinked immunosorbent assay (ELISA and by an indirect Immunoglobulin G (IgG ELISA. Selected IgM-positive (n = 14, IgG-positive (n = 23 and samples negative for both IgM and IgG-specific antibodies against RVF virus (n = 19 were tested using the serum neutralisation test (SNT. Sera from IgM-positive (n = 14 and negative (n = 20 animals were also tested by a TaqMan polymerase chain reaction (PCR. On the affected farm, 7% (16/233 of the cattle were IgM-positive and 13.7% (32/233 IgG-positive at the first bleed and 2% were IgM-positive at the second bleed, whilst the number of cattle positive for IgG-specific antibodies increased by 21.3% compared with the first bleed. Only 1.4% of sheep were positive for both IgM and IgG antibodies at the first collection; at the second bleed, IgM-positive cases decreased to 1.2%, whilst IgG-positive cases increased to 2.4%. Whilst no IgM-positive cattle were found on the neighbouring farm, 5.5% of cattle were IgG-positive. The SNT confirmed most of the ELISA results, whilst PCR results were all negative. Although serology results indicated virus circulation on both farms, the negative PCR results demonstrated that the animals were not viraemic at the time they were sampled. The movement of infected

  15. Recent morphological changes in the Mekong and Bassac river channels, Mekong delta: The marked impact of river-bed mining and implications for delta destabilisation

    Science.gov (United States)

    Brunier, Guillaume; Anthony, Edward J.; Goichot, Marc; Provansal, Mireille; Dussouillez, Philippe

    2014-11-01

    The Mekong delta, in Vietnam, is the world's third largest delta. Densely populated, the delta has been significantly armoured with engineering works and dykes to protect populations and infrastructure from storms, and shrimp farms from saltwater intrusion. Considerable development pressures in Vietnam and in the upstream countries have resulted in the construction of several dams in China and in important channel-bed aggregate extractions especially in Cambodia. The effects of these developments impact the delta dynamics in various ways. In this study, changes in the channel morphology of the Mekong proper and the Bassac, the two main distributaries in the 250 km-long deltaic reach from the Cambodian border to the coast, were analysed using channel depth data for 1998 and 2008. The channels display important and irregular bed changes over the 10-year comparison period, including significant incision and expansion and deepening of numerous pools. The mean depth of both channels increased by more than 1.3 m. Both channels also showed correlative significant bed material losses: respectively 90 million m3 in the Mekong and 110 million m3 in the Bassac over the 10-year period. These important losses over a relatively short period, and weak correlations between bed incision and hydraulic parameters suggest that the marked morphological changes are not in equilibrium with flow and sediment entrainment conditions, and are therefore not related to changes in river hydrology. We claim that aggregate extraction, currently practised on a very large scale in the Mekong delta channels and upstream of the delta, is the main cause of these recent morphological changes. These changes are deemed to contribute actively to rampant bank erosion in the delta as well as to erosion of the Mekong delta shoreline. Other contributory activities include the numerous dykes and embankments. The role of existing dams in bed losses remains unclear in the absence of reliable data on the Mekong

  16. A study of the climate change impacts on fluvial flood propagation in the Vietnamese Mekong Delta

    Science.gov (United States)

    Van, P. D. T.; Popescu, I.; van Griensven, A.; Solomatine, D. P.; Trung, N. H.; Green, A.

    2012-12-01

    The present paper investigated the extent of the flood propagation in the Vietnamese Mekong Delta under different projected flood hydrographs, considering the 2000 flood event (the 20-yr return period event, T. V. H. Le et al., 2007) as the basis for computation. The analysis herein was done to demonstrate the particular complexity of the flood dynamics, which was simulated by the 1-D modelling system ISIS used by the Mekong River Commission. The floods of the year 2050 are simulated using a projected sea level rise of +30 cm. The future flood hydrograph changes at Kratie, Cambodia, were also applied for the upstream boundary condition by using an adjusted regional climate model. Two future flood hydrographs were applied at the upstream part of the delta, the first one in a scenario of climate change without considering developments in the Mekong Basin,and the second one in a scenario of climate change taking into account future development of the delta. Analyses were done to identify the areas sensitive to floods, considering the uncertainty of the projection of both the upstream and downstream boundary conditions. In addition, due to the rice-dominated culture in the Vietnamese Mekong Delta, possible impacts of floods on the rice-based farming systems were also analysed.

  17. A study of the climate change impacts on fluvial flood propagation in the Vietnamese Mekong Delta

    Directory of Open Access Journals (Sweden)

    P. D. T. Van

    2012-12-01

    Full Text Available The present paper investigated the extent of the flood propagation in the Vietnamese Mekong Delta under different projected flood hydrographs, considering the 2000 flood event (the 20-yr return period event, T. V. H. Le et al., 2007 as the basis for computation. The analysis herein was done to demonstrate the particular complexity of the flood dynamics, which was simulated by the 1-D modelling system ISIS used by the Mekong River Commission. The floods of the year 2050 are simulated using a projected sea level rise of +30 cm. The future flood hydrograph changes at Kratie, Cambodia, were also applied for the upstream boundary condition by using an adjusted regional climate model. Two future flood hydrographs were applied at the upstream part of the delta, the first one in a scenario of climate change without considering developments in the Mekong Basin,and the second one in a scenario of climate change taking into account future development of the delta. Analyses were done to identify the areas sensitive to floods, considering the uncertainty of the projection of both the upstream and downstream boundary conditions. In addition, due to the rice-dominated culture in the Vietnamese Mekong Delta, possible impacts of floods on the rice-based farming systems were also analysed.

  18. 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

    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...

  19. 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.

  20. Are the fish of the upper and lower Mekong interconnected?

    Institute of Scientific and Technical Information of China (English)

    KANG Bin; PERRETT Lisa; LI Yungang; HE Daming

    2009-01-01

    The Mekong supports one of the richest inland fisheries in the world, with many of the fish migrating long distance to spawn. Little is known about the fisheries and migration strategies of the Upper Mekong whilst it is supposed that many fish species move between the Lower and Upper Mekong. Most likely, natural fish migration in the fiver has been altered by dam construction across the mainstream of the Upper Mekong. In this paper, the interconnectivity of fish species between different sections of the Mekong and negative impacts of dams on migratory fish are studied. Of the 162 fish species in the Upper Mekong and the 869 species in the Lower Mekong, 61 species are common. Results show that there is no significant difference at order level between the UM and LM. Similarity coefficients are used to evaluate interconnectivity at species, genus and family levels among four different sections of the Upper Mekong with each other and with the Lower Mekong as a whole. The highest similarity is found between the middle and lower reach of the Upper Mekong at species and genus levels and the middle and upper reach at family level. Of the eight cascade dams, Mengsong Dam in planning is considered as the biggest threat to migratory fish from the Lower Mekong and should be particularly concerned.

  1. 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.

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

    NARCIS (Netherlands)

    Phu, Tran Minh; Phuong, Nguyen Thanh; Dung, Tu Thanh; Hai, Dao Minh; Son, Vo Nam; Rico Artero, Andreu; Clausen, Jesper Hedegaard; Madsen, Henry; Murray, Francis; Dalsgaard, Anders

    2016-01-01

    This study aimed to evaluate the current status on the use of probiotics, disinfectants and antimicrobials in hatcheries, nurseries and grow-out farms producing Pangasius catfish (Pangasianodon hypophthalmus) in the Mekong Delta, Vietnam. Semi-structured interviews were conducted with 83 aquacult

  3. 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

    This study aimed to evaluate the current status on the use of probiotics, disinfectants and antimicrobials in hatcheries, nurseries and grow-out farms producing Pangasius catfish (Pangasianodon hypophthalmus) in the Mekong Delta, Vietnam. Semi-structured interviews were conducted with 83...

  4. Soil Protection measures based on the analysis if sediment sources in a commercial farm at the Guadalquivir Valley (Spain)

    Science.gov (United States)

    Albert, Enrique; Brígido, Consuelo; Herrera, Pascual; Migallón, Jose Ignacio; Taguas, Encarnación V.

    2016-04-01

    High soil losses are associated with agricultural areas dedicated to traditional crops in Spain (olive, grapevine, almond and sunflower, among others) and they caused by interacting drivers such as frequent intense events, steep/hilly slopes and unsuitable managements (De Santisteban et al., 2006). These crops are essential for the Spanish economy but at the same time, they constitute important areas of soil degradation. This work has been promoted by a farm owner interested in improving the sustainability of his farm as well as solving traffic problems derived from a gully. An analysis based on a modeling approach and field measurements was carried out in order to diagnose the main sediment sources of a farm with traditional Mediterranean crops (sunflower and olives) and to propose actions for optimizing soil conservation efforts. Firstly, an environmental study to characterize meteorological and topographical features, soil properties and managements was performed. The farm was divided in different areas belonging to the same hydrological catchment, land-use and management. Secondly, splash and inter-rill erosion were evaluated in each spatial unit through the RUSLE model. Rills and gullies in the catchment were also measured by using orthophotographies and a tape in the field to calculate their corresponding sediment volume. Finally, a plan of soil protection measures was designed and presented to the owner who will apply the proposed actions, mainly cover crop seeding and construction of check dams. REFERENCES: De Santisteban, L. M., J. Casalí, and J. J. López. 2006. Assessing soil erosion rates in cultivated areas of Navarre (Spain). Earth Surf. Process. Landforms 31: 487-506.

  5. Mapping Landcover/Landuse and Coastline Change in the Eastern Mekong Delta (Viet Nam) from 1989 to 2002 using Remote Sensing

    OpenAIRE

    SOHAIL, ARFAN

    2012-01-01

    There has been rapid change in the landcover/landuse in the Mekong delta, Viet Nam. The landcover/landuse has changed very fast due to intense population pressure, agriculture/aquaculture farming and timber collection in the coastal areas of the delta. The changing landuse pattern in the coastal areas of the delta is threatened to be flooded by sea level rise; sea level is expected to rise 33 cm until 2050; 45 cm until 2070 and 1 m until 2100. The coastline along the eastern Mekong delta has ...

  6. Use of Unmanned Aerial Vehicles for Improving Farm Scale Agricultural Water Management in Agriculture at a Farm Scale. A case study for field crops in the California's Central Valley

    Science.gov (United States)

    Medellin-Azuara, J.; Morande, J. A.; Jin, Y.; Chen, Y.; Paw U, K. T.; Viers, J. H.

    2016-12-01

    Traditional methods for estimating consumptive water use as evapotranspiration (ET) for agriculture in areas with water limitations such as California have always been a challenge for farmers, water managers, researchers and government agencies. Direct measurement of evapotranspiration (ET) and crop water stress in agriculture can be a cumbersome and costly task. Furthermore, spatial variability of applied water and irrigation and stress level in crops, due to inherent heterogeneity in soil conditions, topography, management practices, and lack of uniformity in water applications may affect estimates water use efficiency and water balances. This situation difficult long-term management of agroecosystems. This paper presents a case study for various areas in California's Central Valley using Unmanned Aerial Vehicles (UAVs) for a late portion of the 2016 irrigation season These estimates are compared those obtained by direct measurement (from previously deployed stations), and energy balance approaches with remotely sensed data in a selection of field crop parcels. This research improves information on water use and site conditions in agriculture by enhancing remote sensing-based estimations through the use of higher resolution multi-spectral and thermal imagery captured by UAV. We assess whether more frequent information at higher spatial resolution from UAVs can improve estimations of overall ET through energy balance and imagery. Stress levels and ET are characterized spatially to examine irrigation practices and their performance to improve water use in the agroecosystem. Ground based data such as air and crop temperature and stem water potential is collected to validate UAV aerial measurements. Preliminary results show the potential of UAV technology to improve timing, resolution and accuracy in the ET estimation and assessment of crop stress at a farm scales. Side to side comparison with ground level stations employing surface renewal, eddy covariance and

  7. A study of the climate change impacts on fluvial flood propagation in the Vietnamese Mekong Delta

    Directory of Open Access Journals (Sweden)

    V. P. Dang Tri

    2012-06-01

    Full Text Available The present paper investigated what would be the flood propagation in the Vietnamese Mekong Delta (VMD, due to different projected climate change scenarios, if the 2000 flood event (the most recent highest flood in the history was taken as a base for computation. The analysis herein was done to demonstrate the particular complexity of the flood dynamics. The future floods, on short term horizon, year 2050, were studied by considering the projected sea level rise (SLR (+30 cm. At the same time, future flood hydrograph changes at Kratie, Cambodia were applied for the upstream boundary condition. In this study, the future flood hydrograph was separated into two scenarios in which: (i Scenario 1 was projected in 2050 according to the adjusted regional climate model without any development in the Upper Mekong Basin; and, (ii Scenario 2 was projected as in Scenario 1 but with the development of the Upper Mekong Basin after 2030. Analyses were done to identify the high sensitive areas in terms of flood conditions (i.e. with and without flood according to the uncertainty of the projection of both the upstream and downstream boundary conditions. In addition, due to the rice-dominated culture in the VMD, possible impacts of flood on the rice-based farming systems were analysed.

  8. 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.

  9. Caracterização da piscicultura na região do Vale do Ribeira - SP Characterization of fish farming in the Ribeira Valley region - SP

    Directory of Open Access Journals (Sweden)

    Daniela Castellani

    2005-02-01

    Full Text Available Este trabalho buscou caracterizar a piscicultura na Região do Vale do Ribeira quanto aos sistemas de manejo. Estudaram-se quarenta e duas pisciculturas sendo que, destas, 36 praticam o sistema semi-intensivo e seis o sistema intensivo, com os seguintes objetivos: engorda de peixes, produção de alevinos e pesque-pagues. Foram listadas 41 espécies de peixes cultivadas. Apenas 6 espécies são nativas da Bacia do Rio Ribeira de Iguape: lambari (Astyanax sp Linneaus, 1758, traíra (Hoplias malabaricus Bloch, 1794, robalo (Centropomus ssp Cuvier e Valenciennes, 1928, jundiá (Rhamdia quelen Quoy e Gaimard, 1824, cascudo (Hypostomus sp Marschall, 1873 e cará (Geophagus brasiliensis Quoy e Gaimard, 1824. Em 95% das pisciculturas foram verificadas fugas de peixes exóticos e alóctones dos cultivos. A tilápia nilótica (Oreochromis niloticus Linneaus, 1758 foi a espécie mais freqüente em escapes, e também é a segunda mais cultivada pelos piscicultores, perdendo somente para o pacu (Piaractus mesopotamicus Halmberg, 1887. Foi possível verificar mediante o cálculo da conversão alimentar, que há um desperdício anual de cerca de 32% da ração utilizada nos cultivos pesquisados. A piscicultura encontra-se em plena expansão nesta região, e já representa a atividade agropecuária mais importante após a bananicultura.The aim of this work was to characterize the fish farming in the Ribeira de Iguape Basin, southern São Paulo State (Brazil, in relation to the management systems. Forty two farms were studied. A semi-intensive system is used by 36 farmers, while an intensive system is used only by 6 studied farmers. Their objectives were raising fish, juvenile fish production and sportive fishery. Forty one fish species were found to be cultivated, but only six were native species from Ribeira Valley: lambari (Astyanax sp Linneaus, 1758, traíra (Hoplias malabaricus Bloch, 1794, robalo (Centropomus ssp Cuvier and Valenciennes, 1928, jundi

  10. Osmoregulatory and immunological status of the pond-raised striped catfish (Pangasianodon hypophthalmus S.) as affected by seasonal runoff and salinity changes in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Schmitz, Mélodie; Baekelandt, Sébastien; Tran Thi, Lam Khoa; Mandiki, Syaghalirwa N M; Douxfils, Jessica; Nguyen, Thinh Quoc; Do Thi Thanh, Huong; Kestemont, Patrick

    2017-02-01

    In Vietnam, the production of striped catfish Pangasianodon hypophthalmus S. reached more than 1.2 millions of tons in 2014 and is mainly gathered in the Mekong Delta (South Vietnam). A survey was carried out during the dry season 2013 (March-April) and rainy season 2014 (July-August) in 12 fish farms of the lower (Tra Vinh Province) and higher (Can Tho Province) Mekong River Delta. This study allowed drawing up current key osmoregulatory and innate immune parameters of striped catfish in aquaculture depending on the geographical location, particularly the proximity to the River Mekong Estuary and the seasonal surface runoff. In the dry season, plasma osmolality was positively correlated with salinity. Gill Na(+)K(+) ATPase dropped in the rainy season, while kidney Na(+)K(+) ATPase remained stable. Abundance of immune blood cells, especially thrombocytes and monocytes, tended to increase in farms located in tidal area. Production of reactive oxygen species in the spleen, kidney lysozyme activity and plasma complement activity did not vary whatever the season or the proximity to the estuary. Plasma lysozyme activity was 50-fold higher than in kidney and increased in the rainy season as well as in tidal sites. Kidney complement activity decreased in the dry season, especially in tidal sites. In conclusion, regarding key osmoregulatory and immune factors, striped catfish farms located in the Mekong Delta may be affected by seasonal and regional salinity and runoff fluctuations.

  11. The impacts of the expansion of fruit farming businesses In the Commune of Llay Llay, Aconcagua Valley, Chile

    Directory of Open Access Journals (Sweden)

    Claudia Gonzalez Cid

    2014-12-01

    Full Text Available The commune of Llay Llay is characterized by the existence of a regional economy structured around fruit farming businesses. The operations of these enterprises have not had a beneficial impact on the area. Rather has been confronted by a dual predicament: temporary work and low wages. As well, the environment is threatened as the agricultural frontier extends into the foothills of the nearby mountain ranges. In addition, there is evidence of increased land concentration and control of water on the part of the agribusinesses, to the detriment of the livelihoods of small producers.  The loss of land and water is the other face of a peasant proletarization process that is ultimately functional to the agribusinesses needs for financial and human resources

  12. Cultivation techniques in a 34 years old farming oak (Quercus robur L. plantation in the Arno valley (Tuscany

    Directory of Open Access Journals (Sweden)

    Serena Ravagni

    2015-12-01

    Full Text Available This report aims to provide a description of the cultivation techniques adopted at the oldest oak pure plantation (age 34 established within the environmental restoration plan of soil dumps at the Santa Barbara ENEL Company opencast mine in Cavriglia (AR. The goals of the initial plan, following which the plantation was carried out, were to (i verify the possibility of restoring the soil dump by using tree farming plantations and produce a range of valuable timber assortments; (ii test the growth potential of the oak species in a pure plantation. The plantation, carried out with a stem density of 1,111 trees per hectare, was managed by targeted practices (pruning up to the stem height of 4-5 m and then undertaking four thinnings.  A geometric-selective thinning was applied first and, later, periodical thinning from above was implemented, releasing, as a result, about 70 crop trees per hectare. In the meanwhile, it was possible to monitor  the growth parameters concerning dbh, tree height and crown diameter. The stem quality and the presence of epicormic branches were evaluated in 2013 and the relationship between the presence of epicormic branches and tree characteristics were also analyzed. The wood production was compared with other European plantations, especially from France. Today, 34 years after the plantation got started, the site is an interesting case-study of tree farming as it plays a consistent role within the environmental restoration of the area. The applied management system allowed to reach a noticeable wood production level andalso valuable timber assortments for industrial use. Crop trees (70 per hectare reached a mean dbh of 38.1 cm, the height of 22.3 m at the age of 34. 

  13. Vietnam and the sustainable development of the Mekong river basis.

    Science.gov (United States)

    Quang, Nguyen Nhan

    2002-01-01

    Vietnam is a riparian country located in most downstream area of the Mekong river basin which is also shared by other states namely China, Myanmar, Laos, Thailand and Cambodia. While the Central Highlands of Vietnam has a great potential for hydropower development in tributaries of Mekong river, the Mekong delta in Vietnam territory is rich in natural resources which are favorable for agricultural development. However, besides local constraints which being gradually remedied by Vietnam, the development of the Mekong delta is subject to, in both terms of quantity and quality, availability of water resources which relates to the water use of or discharge into the river of upper riparians. With a view to co-developing these resources in a sustainable and mutually beneficial manner, Vietnam has cooperated with other states through framework of the Mekong River Commission set up by the 1995 Mekong Agreement. This paper describes the strategy and action plan applied by Viet Nam National Mekong Committee to reach the sustainable development of the Mekong river basin in general and of Vietnam parts located in the Mekong basin in particular.

  14. Mitigating the environmental impacts of milk production via anaerobic digestion of manure: case study of a dairy farm in the Po Valley.

    Science.gov (United States)

    Battini, F; Agostini, A; Boulamanti, A K; Giuntoli, J; Amaducci, S

    2014-05-15

    This work analyzes the environmental impacts of milk production in an intensive dairy farm situated in the Northern Italy region of the Po Valley. Three manure management scenarios are compared: in Scenario 1 the animal slurry is stored in an open tank and then used as fertilizer. In scenario 2 the manure is processed in an anaerobic digestion plant and the biogas produced is combusted in an internal combustion engine to produce heat (required by the digester) and electricity (exported). Scenario 3 is similar to scenario 2 but the digestate is stored in a gas-tight tank. In scenario 1 the GHG emissions are estimated to be equal to 1.21 kg CO2 eq.kg(-1) Fat and Protein Corrected Milk (FPCM) without allocation of the environmental burden to the by-product meat. With mass allocation, the GHG emissions associated to the milk are reduced to 1.18 kg CO2 eq.kg(-1) FPCM. Using an economic allocation approach the GHG emissions allocated to the milk are 1.13 kg CO2 eq.kg(-1) FPCM. In scenarios 2 and 3, without allocation, the GHG emissions are reduced respectively to 0.92 (-23.7%) and 0.77 (-36.5%) kg CO2 eq.kg(-1) FPCM. If land use change due to soybean production is accounted for, an additional emission of 0.53 kg CO2 eq. should be added, raising the GHG emissions to 1.74, 1.45 and 1.30 kg CO2 eq kg(-1) FPCM in scenarios 1, 2 and 3, respectively. Primary energy from non-renewable resources decreases by 36.2% and 40.6% in scenarios 2 and 3, respectively, with the valorization of the manure in the biogas plant. The other environmental impact mitigated is marine eutrophication that decreases by 8.1% in both scenarios 2 and 3, mostly because of the lower field emissions. There is, however, a trade-off between non-renewable energy and GHG savings and other environmental impacts: acidification (+6.1% and +5.5% in scenarios 2 and 3, respectively), particulate matter emissions (+1.4% and +0.7%) and photochemical ozone formation potential (+41.6% and +42.3%) increase with the

  15. The role of a fish pond in optimizing nutrient flows in integrated agriculture-aquaculture farming systems

    NARCIS (Netherlands)

    Nhan, D.K.

    2007-01-01

      In the Mekong delta, the Vietnamese government promoted integrated agriculture-aquaculture (IAA) farming systems as an example of sustainable agriculture. An important advantage of IAA-farming is the nutrient linkage between the pond and terrestrial components within a f

  16. The role of a fish pond in optimizing nutrient flows in integrated agriculture-aquaculture farming systems

    NARCIS (Netherlands)

    Nhan, D.K.

    2007-01-01

      In the Mekong delta, the Vietnamese government promoted integrated agriculture-aquaculture (IAA) farming systems as an example of sustainable agriculture. An important advantage of IAA-farming is the nutrient linkage between the pond and terrestrial components within a

  17. The role of a fish pond in optimizing nutrient flows in integrated agriculture-aquaculture farming systems

    NARCIS (Netherlands)

    Nhan, D.K.

    2007-01-01

      In the Mekong delta, the Vietnamese government promoted integrated agriculture-aquaculture (IAA) farming systems as an example of sustainable agriculture. An important advantage of IAA-farming is the nutrient linkage between the pond and terrestrial components within a f

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

    Science.gov (United States)

    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

    2015-04-01

    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 antimicrobials (usage per week per chicken and usage per 1000 chickens produced) in the Mekong Delta and to investigate factors associated with usage. Twenty-eight types of antimicrobial belonging to 10 classes were reported. Sixty-three per cent of all commercial formulations contained at least two antimicrobials. On 84% occasions, antimicrobials were administered with a prophylactic purpose. The overall adjusted quantities of antimicrobials used/week/chicken and per 1000 chickens produced (g) were 26.36 mg (SE ± 3.54) and 690.4 g (SE ± 203.6), respectively. Polypeptides, tetracyclines, penicillins and aminoglycosides were the antimicrobials used by most farms (18.6% farms, 17.5%, 11.3% and 10.1% farms, respectively), whereas penicillins, lincosamides, quinolones, and sulphonamides/trimethoprim were quantitatively the most used compounds (8.27, 5.2, 3.16 and 2.78 mg per week per chicken, respectively). Factors statistically associated with higher levels of usage (per week per chicken) were meat farms (OR = 1.40) and farms run by a male farmer (OR = 2.0). All-in-all-out farming systems (correlated with medium farms) were associated with reduced levels of antimicrobial usage (OR = 0.68). Usage levels to produced meat chickens were considerably higher than those reported in European countries. This should trigger the implementation of surveillance programmes to monitor sales of antimicrobials that should contribute to the rational administration of antimicrobials in order to preserve the efficacy of existing antimicrobials in Vietnam.

  19. Mekong sub-region committed to ending trafficking

    Directory of Open Access Journals (Sweden)

    Susu Thatun

    2006-05-01

    Full Text Available In October 2004 six countries - Cambodia, China, Laos, Myanmar/Burma, Thailand and Vietnam – joined hands in the battle against human trafficking in the Greater Mekong Sub-region (GMS.

  20. 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

  1. Quaternary Morphodynamics for two large rivers: the Fly River, PNG, and the Mekong River, Cambodia.

    Science.gov (United States)

    Aalto, R. E.; Lauer, J. W.; Darby, S. E.; Goni, M. A.; Dietrich, W. E.

    2014-12-01

    During glacial marine transgressions, sediment & carbon are deposited due to the infilling of lowland fluvial systems, material that is then largely removed during ensuing regressions. Measuring & modelling these processes would help quantify the amount, timing, & preservation of these materials, providing insight into the morphodynamics of lowland fluvial systems in response to sea level change. We investigated the infilling dynamics of the Fly and Strickland Rivers, Papua New Guinea. Field data include: 14C dated deep cores recording base level evolution over the Holocene, sonar imaging of floodbasin stratigraphy, and the observations of blocked valley lakes and weathered erosional remnants from LGM conditions. Similar research was conducted on the Mekong River, Cambodia, where we have imaged basin fill stratigraphy and recorded the extent of blocked valley lakes. Such field data provide tantalizing empirical glimpses into the landscapes & flux buffering exhibited by large tropical rivers during glacial-interglacial transitions. We upscale our observations by modelling river system evolution, employing a GpU Lowland Landscape Evolution Model (GULLEM) to predict the evolution of the entire basin. A novel & powerful (>10 Tflops on an inexpensive computer) simulator, GULLEM models morphodynamics and estimates the accommodation space subsequently infilled during marine transgressions by representing a range of geomorphic processes, including: river & tributary incision, non-linear diffusion, sea level and isostatic change, hydraulic geometry, tectonic deformation, sediment production, transport & deposition, & tracking of the resulting stratigraphy. GULLEM's vectorized approach allows for massively parallel operation on GPUs (Graphics Processing Unit), making it practical to model coupled fluvial-landscape evolution for complex lowland river systems over large temporal and spatial scales. Our combined approach affords estimates for the timing and budgets of sediment

  2. Sugar beet activities of the USDA-ARS East Lansing conducted in cooperation with Saginaw Valley Bean and Beet Farm during 2010

    Science.gov (United States)

    Cercospora leaf spot resistance evaluation plots were planted at the Saginaw Valley Research & Extension Center in Frankenmuth, MI in 2010. All trials were planted, following normal fall and spring tillage operations, with a USDA-ARS modified John Deere/Almaco research plot planter utilizing global ...

  3. Sugar Beet Activities of the USDA-ARS East Lansing Conducted in Cooperation with Saginaw Valley Bean and Beet Farm During 2009

    Science.gov (United States)

    Two evaluation plots were planted at the Saginaw Valley Research & Extension Center in Frankenmuth, MI in 2009; one agronomic trial and one combined Cercospora evaluation trial. All trials were planted, following normal fall and spring tillage operations, with a USDA-ARS modified John Deere/Almaco ...

  4. Paleoclimatological perspective on the hydrometeorology of the Mekong Basin

    Directory of Open Access Journals (Sweden)

    T. A. Räsänen

    2012-11-01

    Full Text Available During recent decades the Mekong River has experienced substantial interannual variations between droughts and major floods. The causes of these variations have been sought in climate change and dam construction. However, so far little research has addressed whether these recent variations are significantly different to long-term variations in the past. Hence, the aim of our paper is to place the recent variations between droughts and floods into a historical and paleoclimatological context. To achieve this we analysed the Mekong's meteorological conditions over the period 1300–2005 with a basin scale approach by using the Monsoon Asia Drought Atlas (MADA, which is a Palmer Drought Severity Index (PDSI dataset derived from tree-ring growth records. The correlation analyses, both in time and frequency domains, showed correlation between MADA and the Mekong's discharge over the period 1910–2005 which suggests that MADA can be used as proxy for the hydrometeorology of the Mekong Basin. We found that the meteorological conditions of the Mekong varied at multi-annual, decadal and centennial scales over the study period. We found two especially distinct features: firstly, multi-annual and decadal variation between prolonged wet and dry epochs; and secondly, epochs with higher or lower interannual variability between very dry and wet years. Furthermore we found two epochs with exceptionally large interannual variability, one at the beginning of 17th century and the other in the post 1950 epoch. Both epochs are characterized by distinct increases in variability between very wet and dry years. The variability in the post 1950 epoch is much higher compared to any of the other epochs included in this study. Thus, during recent decades the climate in the Mekong has exhibited features that have not been experienced for at least several centuries. These findings call for further climate research, particularly regarding increased climate variability, and

  5. Paleoclimatological perspective on the hydrometeorology of the Mekong Basin

    Science.gov (United States)

    Räsänen, T. A.; Lehr, C.; Mellin, I.; Ward, P. J.; Kummu, M.

    2012-11-01

    During recent decades the Mekong River has experienced substantial interannual variations between droughts and major floods. The causes of these variations have been sought in climate change and dam construction. However, so far little research has addressed whether these recent variations are significantly different to long-term variations in the past. Hence, the aim of our paper is to place the recent variations between droughts and floods into a historical and paleoclimatological context. To achieve this we analysed the Mekong's meteorological conditions over the period 1300-2005 with a basin scale approach by using the Monsoon Asia Drought Atlas (MADA), which is a Palmer Drought Severity Index (PDSI) dataset derived from tree-ring growth records. The correlation analyses, both in time and frequency domains, showed correlation between MADA and the Mekong's discharge over the period 1910-2005 which suggests that MADA can be used as proxy for the hydrometeorology of the Mekong Basin. We found that the meteorological conditions of the Mekong varied at multi-annual, decadal and centennial scales over the study period. We found two especially distinct features: firstly, multi-annual and decadal variation between prolonged wet and dry epochs; and secondly, epochs with higher or lower interannual variability between very dry and wet years. Furthermore we found two epochs with exceptionally large interannual variability, one at the beginning of 17th century and the other in the post 1950 epoch. Both epochs are characterized by distinct increases in variability between very wet and dry years. The variability in the post 1950 epoch is much higher compared to any of the other epochs included in this study. Thus, during recent decades the climate in the Mekong has exhibited features that have not been experienced for at least several centuries. These findings call for further climate research, particularly regarding increased climate variability, and resilient adaptation

  6. 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

  7. Mekong River flow and hydrological extremes under climate change

    NARCIS (Netherlands)

    Hoang, P.L.; Lauri, P.; Kummu, M.; Koponen, J.; Vliet, van M.T.H.; Supit, I.; Leemans, H.B.J.; Kabat, P.; Ludwig, F.

    2016-01-01

    Climate change poses critical threats to water related safety and sustainability in the Mekong River basin. Hydrological impact signals derived from CMIP3 climate change scenarios, however, are highly uncertain and largely ignore hydrological extremes. This paper provides one of the first hydrologic

  8. 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 develop

  9. Bartonella species and trombiculid mites of rats from the Mekong Delta of Vietnam.

    Science.gov (United States)

    Loan, Hoang Kim; Cuong, Nguyen Van; Takhampunya, Ratree; Klangthong, Kewalin; Osikowicz, Lynn; Kiet, Bach Tuan; Campbell, James; Bryant, Juliet; Promstaporn, Sommai; Kosoy, Michael; Hoang, Nguyen Van; Morand, Serge; Chaval, Yannick; Hien, Vo Be; Carrique-Mas, Juan

    2015-01-01

    A survey of Bartonella spp. from 275 rats purchased in food markets (n=150) and trapped in different ecosystems (rice field, forest, and animal farms) (n=125) was carried out during October, 2012-March, 2013, in the Mekong Delta of Vietnam. The overall Bartonella spp. prevalence detected by culture and PCR in blood was 14.9% (10.7-19.1%), the highest corresponding to Rattus tanezumi (49.2%), followed by Rattus norvegicus (20.7%). Trapped rats were also investigated for the presence and type of chiggers (larvae of trombiculid mites), and Bartonella spp. were investigated on chigger pools collected from each rat by RT-PCR. A total of five Bartonella spp. were identified in rats, three of which (B. elizabethae, B. rattimassiliensis, and B. tribocorum) are known zoonotic pathogens. Among trapped rats, factors independently associated with increased prevalence of Bartonella spp. included: (1) Rat species (R. tanezumi); (2) the number of Trombiculini-Blankaartia and Schoengastiini-Ascoschoengastia mites found on rats; and (3) the habitat of the rat (i.e., forest/fields vs. animal farms). The prevalence of Bartonella infection among chiggers from Bartonella spp.-positive R. tanezumi rats was 5/25 (25%), compared with 1/27 (3.7%) among Bartonella spp.-negative R. tanezumi rats (relative risk [RR]=5.4, 95% confidence interval [CI] 0.68-43.09). The finding of Bartonella spp.-positive chiggers on Bartonella spp.-negative rats is strongly suggestive of a transovarial transmission cycle. Rats are ubiquitous in areas of human activity and farms in the Mekong Delta; in addition, trapping and trading of rats for food is common. To correctly assess the human risks due to rat trapping, marketing, and carcass dressing, further studies are needed to establish the routes of transmission and cycle of infection. The widespread presence of these zoonotic pathogens in rats and the abundance of human-rat interactions suggest that surveillance efforts should be enhanced to detect any human

  10. 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

  11. The Changing Political Dynamics of Dam Building on the Mekong

    Directory of Open Access Journals (Sweden)

    Philip Hirsch

    2010-06-01

    Full Text Available This paper explores political dynamics surrounding dam building in the Mekong river basin, prior to, and following, the World Commission on Dams (WCD. Since the 1950s, dam building in the Mekong river basin has been enmeshed in a complex and shifting geopolitical and eco-political landscape. The broad geopolitical sweep of US hegemony, Cold War, regional rapprochement and the rise of China has been superimposed on eco-political shifts between modernist belief in progress as mastery over nature, concerns of global and national environmental movements over dams and their impacts, and a galvanised Mekong environmentalism. During the first decade of the 21st century, mainstream dams on the Lower Mekong have returned to the agenda after having almost disappeared in favour of tributary projects. The growing strength and assertiveness of regional economic players has fundamentally altered the context of energy demand, planning and investment. New sources of finance have relocated the points of political leverage. Environment has been mustered in favour of, as well as in opposition to, dam construction in the contexts of climate-change discourses, protected-area linkage with dam projects, and an industry push for sustainability protocols and certification. Despite the Mekong being one of its focal basins, WCD has not played a prominent role in this transformed arena, yet many of the social and environmental concerns, stakeholder-based processes and safeguard-oriented approaches to hydropower planning that WCD brought to the fore have persisted in the wider ethos of politics around dams in the region.

  12. 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.

  13. Application and Exploration of Container Building in Urban Farm:Take Kunming Maple Valley Urban Farm Container Building as the Case%集装箱建筑在都市农庄中的应用与探索--以昆明金殿后山枫叶谷都市农庄集装箱建筑为例

    Institute of Scientific and Technical Information of China (English)

    张濒予; 翟辉

    2016-01-01

    The rise of a large number of container buildings in the world makes it become a regular branch of architecture. Based on Kunming Maple Valley Urban Farm container architectural design, this paper explores the advantages of using containers as the main building material compared to general material, and analyzes the value of container construction and the practice summary, which provides inspiration for architectural design of urban farm.%集装箱建筑在世界范围内大量的兴起使其被作为一个常规建筑学的分支。以昆明枫叶谷都市农庄集装箱建筑设计为依托,探讨用集装箱作为建筑主要材料时与一般性材料的优势的比较,并浅析集装箱建筑存在的价值及实践总结,为都市农庄中建筑设计的创作提供思路和启发。

  14. 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

  15. Drew Goodman, Earthbound Farm

    OpenAIRE

    Rabkin, Sarah

    2010-01-01

    Drew Goodman is CEO and co-founder, with his wife, Myra, of Earthbound Farm, based in San Juan Bautista, California. Two years after its 1984 inception on 2.5 Carmel Valley acres, Earthbound became the first successful purveyor of pre-washed salads bagged for retail sale. The company now produces more than 100 varieties of certified organic salads, fruits, and vegetables on a total of about 33,000 acres, with individual farms ranging from five to 680 acres in California, Arizona, Washington, ...

  16. Review: Louis Lebel, John Dore, Rajesh Daniel, and Yang Saing Koma (eds.: Democratizing Water Governance in the Mekong Region (2007 Buchbesprechung: Louis Lebel, John Dore, Rajesh Daniel, and Yang Saing Koma (eds.: Democratizing Water Governance in the Mekong Region (2007

    Directory of Open Access Journals (Sweden)

    Henriette Litta

    2009-04-01

    Full Text Available Review of the edited volume: Louis Lebel, John Dore, Rajesh Daniel, and Yang Saing Koma (eds.: Democratizing Water Governance in the Mekong Region Chiang Mai, Thailand: Mekong Press, 2007, ISBN 978-974-9511-25-1, 304 pages Besprechung des Sammelbandes: Louis Lebel, John Dore, Rajesh Daniel, and Yang Saing Koma (Hrsg.: Democratizing Water Governance in the Mekong Region Chiang Mai, Thailand: Mekong Press, 2007, ISBN 978-974-9511-25-1, 304 Seiten.

  17. 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

  18. Valley Fever

    Science.gov (United States)

    Valley Fever is a disease caused by a fungus (or mold) called Coccidioides. The fungi live in the soil ... from person to person. Anyone can get Valley Fever. But it's most common among older adults, especially ...

  19. Country Report on China's Participation in Greater Mekong Subregion Cooperation

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    1.Executive SummaryThe Mekong River,which originates from the Danggula Mountain Range on the Qinghai-Tibet Plateau in China and runs 4,880 km southward through six countries,namely,China,Myartmar,Laos,Thailand,Cambodia and Viet Nam,is an important transnational river in Asia and even the world.The section in China is called the Lancang River.Since the 1990s,the international cooperation in the Lancang-Mekong subregiun has received wide attention from the international community.Related countries and intemational organizations have carried out extensive cooperation,which has produced good results and forcefully facilitated economic and social development of the subregion.

  20. Mekong River flow and hydrological extremes under climate change

    OpenAIRE

    Hoang, L.P.; H. Lauri; M. Kummu; Koponen, J.; van Vliet, M. T. H.; I. Supit; Leemans, R.; Kabat, P.; Ludwig, F.

    2016-01-01

    Climate change poses critical threats to water-related safety and sustainability in the Mekong River basin. Hydrological impact signals from earlier Coupled Model Intercomparison Project phase 3 (CMIP3)-based assessments, however, are highly uncertain and largely ignore hydrological extremes. This paper provides one of the first hydrological impact assessments using the CMIP5 climate projections. Furthermore, we model and analyse changes in river flow regimes and hydrologica...

  1. Mekong Regional Land Cover Monitoring System Reference Methods

    Science.gov (United States)

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

    2016-12-01

    In 2015, SERVIR-Mekong conducted a geospatial needs assessment for the Lower Mekong countries which included individual country consultations. The assessment revealed 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 and accuracy assessment do not always meet the needs of key user groups. In addition, data products stop at political boundaries and are often not accessible. Many of the Lower Mekong 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. During this assessment, 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. This system is dependent on a sustainable source of field data that insures data quality and improves potential impact. Based on this need a collaborative workshop was held to create a robust regional reference data system that integrates results from field data, national inventories and high resolution imagery. The results presented here highlights the value of collaboratively developed systems that use data convergence to improve land cover mapping results for multiple end users.

  2. Mekong River flow and hydrological extremes under climate change

    Science.gov (United States)

    Phi Hoang, Long; Lauri, Hannu; Kummu, Matti; Koponen, Jorma; van Vliet, Michelle T. H.; Supit, Iwan; Leemans, Rik; Kabat, Pavel; Ludwig, Fulco

    2016-07-01

    Climate change poses critical threats to water-related safety and sustainability in the Mekong River basin. Hydrological impact signals from earlier Coupled Model Intercomparison Project phase 3 (CMIP3)-based assessments, however, are highly uncertain and largely ignore hydrological extremes. This paper provides one of the first hydrological impact assessments using the CMIP5 climate projections. Furthermore, we model and analyse changes in river flow regimes and hydrological extremes (i.e. high-flow and low-flow conditions). In general, the Mekong's hydrological cycle intensifies under future climate change. The scenario's ensemble mean shows increases in both seasonal and annual river discharges (annual change between +5 and +16 %, depending on location). Despite the overall increasing trend, the individual scenarios show differences in the magnitude of discharge changes and, to a lesser extent, contrasting directional changes. The scenario's ensemble, however, shows reduced uncertainties in climate projection and hydrological impacts compared to earlier CMIP3-based assessments. We further found that extremely high-flow events increase in both magnitude and frequency. Extremely low flows, on the other hand, are projected to occur less often under climate change. Higher low flows can help reducing dry season water shortage and controlling salinization in the downstream Mekong Delta. However, higher and more frequent peak discharges will exacerbate flood risks in the basin. Climate-change-induced hydrological changes will have important implications for safety, economic development, and ecosystem dynamics and thus require special attention in climate change adaptation and water management.

  3. Responding to rising sea levels in the Mekong Delta

    Science.gov (United States)

    Smajgl, A.; Toan, T. Q.; Nhan, D. K.; Ward, J.; Trung, N. H.; Tri, L. Q.; Tri, V. P. D.; Vu, P. T.

    2015-02-01

    Vietnamese communities in the Mekong Delta are faced with the substantial impacts of rising sea levels and salinity intrusion. The construction of embankments and dykes has historically been the principal strategy of the Vietnamese government to mitigate the effects of salinity intrusion on agricultural production. A predicted sea-level rise of 30 cm by the year 2050 is expected to accelerate salinity intrusion. This study combines hydrologic, agronomic and behavioural assessments to identify effective adaptation strategies reliant on land-use change (soft options) and investments in water infrastructure (hard options). As these strategies are managed within different policy portfolios, the political discussion has polarized between choices of either soft or hard options. This paper argues that an ensemble of hard and soft policies is likely to provide the most effective results for people's livelihoods in the Mekong Delta. The consequences of policy deliberations are likely to be felt beyond the Mekong Delta as levels of rice cultivation there also affect national and global food security.

  4. Language Education, Economic Development and Participation in the Greater Mekong Subregion

    Science.gov (United States)

    Bruthiaux, Paul

    2008-01-01

    The Mekong has long attracted interest although it remains economically insignificant. A group of riparian states known as the Greater Mekong Subregion (GMS)--Cambodia, Laos, Myanmar, Thailand, Vietnam and Yunnan Province (China)--now manage aspects of regional development including trade, water management and education. Standard GMS discourse…

  5. Exploring the climate change concerns of striped catfish producers in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

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

    2015-01-01

    This study investigated the perceptions on and adaptations to climate change impacts of 235 pangasius farmers in the Mekong Delta, Vietnam. Data were collected using semi-structured household surveys in six provinces, from three regions along the Mekong river branches. A Chi-Square test was used to

  6. Status and changes of mangrove forest in Mekong Delta: Case study in Tra Vinh, Vietnam

    Science.gov (United States)

    Thu, Phan Minh; Populus, Jacques

    2007-01-01

    Because shrimp culture in the Mekong Delta develops rapidly, it has negatively impacted the environment, socio-economics and natural resources. In particular, mangrove forests have been altered by the shrimp culture. The area of mangrove forests in the region has been reduced and this is seen especially in Tra Vinh province. The results obtained from GIS (Geography Information System) and RS (Remote Sensing) show the status of mangrove forests in Tra Vinh province in 1965, 1995 (Northeastern part of Tra Vinh Province) and 2001. In 1965, the area of mangrove forests was 21,221 ha making up 56% of total land-use, while in 2001 it was 12,797 ha making up 37% of total land-use. Also based on GIS analysis, over the 36 years (1965-2001), the total coverage of mangrove forests have decreased by 50% since 1965. However, the speed of mangrove forest destruction in the period from 1965 to 1995 was much less than that in the period from 1995 to 2001. The average annual reduction in mangrove forest coverage in the first period (1965-1995) was 0.2% whereas it was 13.1% in the later period (1995-2001). For the long time, mangrove deforestation has been caused by war, collection of firewood and clearing for agriculture, and recently, shrimp farming has significantly contributed rate of mangrove destruction.

  7. 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.

  8. 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

  9. Animal Farm

    Institute of Scientific and Technical Information of China (English)

    徐蓉蓉

    2015-01-01

    This essay first introduce the background of Animal Farm and a brief introduction of the author.Then it discuss three thesis about this novel and briefly discussed about it.At last it give highly review on Animal Farm.

  10. Mekong River flow and hydrological extremes under climate change

    Directory of Open Access Journals (Sweden)

    L. P. Hoang

    2015-11-01

    Full Text Available Climate change poses critical threats to water related safety and sustainability in the Mekong River basin. Hydrological impact signals derived from CMIP3 climate change scenarios, however, are highly uncertain and largely ignore hydrological extremes. This paper provides one of the first hydrological impact assessments using the most recent CMIP5 climate change scenarios. Furthermore, we model and analyse changes in river flow regimes and hydrological extremes (i.e. high flow and low flow conditions. Similar to earlier CMIP3-based assessments, the hydrological cycle also intensifies in the CMIP5 climate change scenarios. The scenarios ensemble mean shows increases in both seasonal and annual river discharges (annual change between +5 and +16 %, depending on location. Despite the overall increasing trend, the individual scenarios show differences in the magnitude of discharge changes and, to a lesser extent, contrasting directional changes. We further found that extremely high flow events increase in both magnitude and frequency. Extremely low flows, on the other hand, are projected to occur less often under climate change. Higher low flows can help reducing dry season water shortage and controlling salinization in the downstream Mekong Delta. However, higher and more frequent peak discharges will exacerbate flood risk in the basin. The implications of climate change induced hydrological changes are critical and thus require special attention in climate change adaptation and disaster-risk reduction.

  11. Flood forecasting for River Mekong with data-based models

    Science.gov (United States)

    Shahzad, Khurram M.; Plate, Erich J.

    2014-09-01

    In many regions of the world, the task of flood forecasting is made difficult because only a limited database is available for generating a suitable forecast model. This paper demonstrates that in such cases parsimonious data-based hydrological models for flood forecasting can be developed if the special conditions of climate and topography are used to advantage. As an example, the middle reach of River Mekong in South East Asia is considered, where a database of discharges from seven gaging stations on the river and 31 rainfall stations on the subcatchments between gaging stations is available for model calibration. Special conditions existing for River Mekong are identified and used in developing first a network connecting all discharge gages and then models for forecasting discharge increments between gaging stations. Our final forecast model (Model 3) is a linear combination of two structurally different basic models: a model (Model 1) using linear regressions for forecasting discharge increments, and a model (Model 2) using rainfall-runoff models. Although the model based on linear regressions works reasonably well for short times, better results are obtained with rainfall-runoff modeling. However, forecast accuracy of Model 2 is limited by the quality of rainfall forecasts. For best results, both models are combined by taking weighted averages to form Model 3. Model quality is assessed by means of both persistence index PI and standard deviation of forecast error.

  12. Malaria Modeling and Surveillance for the Greater Mekong Subregion

    Science.gov (United States)

    Kiang, Richard; Adimi, Farida; Soika, Valerii; Nigro, Joseph

    2005-01-01

    At 4,200 km, the Mekong River is the tenth longest river in the world. It directly and indirectly influences the lives of hundreds of millions of inhabitants in its basin. The riparian countries - Thailand, Myanmar, Cambodia, Laos, Vietnam, and a small part of China - form the Greater Mekong Subregion (GMS). This geographical region has the misfortune of being the world's epicenter of falciparum malaria, which is the most severe form of malaria caused by Plasmodium falciparum. Depending on the country, approximately 50 to 90% of all malaria cases are due to this species. In the Malaria Modeling and Surveillance Project, we have been developing techniques to enhance public health's decision capability for malaria risk assessments and controls. The main objectives are: 1) Identifying the potential breeding sites for major vector species; 2) Implementing a malaria transmission model to identify the key factors that sustain or intensify malaria transmission; and 3) Implementing a risk algorithm to predict the occurrence of malaria and its transmission intensity. The potential benefits are: 1) Increased warning time for public health organizations to respond to malaria outbreaks; 2) Optimized utilization of pesticide and chemoprophylaxis; 3) Reduced likelihood of pesticide and drug resistance; and 4) Reduced damage to environment. Environmental parameters important to malaria transmission include temperature, relative humidity, precipitation, and vegetation conditions. These parameters are extracted from NASA Earth science data sets. Hindcastings based on these environmental parameters have shown good agreement to epidemiological records.

  13. Malaria Modeling and Surveillance for the Greater Mekong Subregion

    Science.gov (United States)

    Kiang, Richard; Adimi, Farida; Soika, Valerii; Nigro, Joseph

    2005-01-01

    At 4,200 km, the Mekong River is the tenth longest river in the world. It directly and indirectly influences the lives of hundreds of millions of inhabitants in its basin. The riparian countries - Thailand, Myanmar, Cambodia, Laos, Vietnam, and a small part of China - form the Greater Mekong Subregion (GMS). This geographical region has the misfortune of being the world's epicenter of falciparum malaria, which is the most severe form of malaria caused by Plasmodium falciparum. Depending on the country, approximately 50 to 90% of all malaria cases are due to this species. In the Malaria Modeling and Surveillance Project, we have been developing techniques to enhance public health's decision capability for malaria risk assessments and controls. The main objectives are: 1) Identifying the potential breeding sites for major vector species; 2) Implementing a malaria transmission model to identify the key factors that sustain or intensify malaria transmission; and 3) Implementing a risk algorithm to predict the occurrence of malaria and its transmission intensity. The potential benefits are: 1) Increased warning time for public health organizations to respond to malaria outbreaks; 2) Optimized utilization of pesticide and chemoprophylaxis; 3) Reduced likelihood of pesticide and drug resistance; and 4) Reduced damage to environment. Environmental parameters important to malaria transmission include temperature, relative humidity, precipitation, and vegetation conditions. These parameters are extracted from NASA Earth science data sets. Hindcastings based on these environmental parameters have shown good agreement to epidemiological records.

  14. Financial Impacts of Priority Swine Diseases to Pig Farmers in Red River and Mekong River Delta, Vietnam.

    Science.gov (United States)

    Pham, H T T; Antoine-Moussiaux, N; Grosbois, V; Moula, N; Truong, B D; Phan, T D; Vu, T D; Trinh, T Q; Vu, C C; Rukkwamsuk, T; Peyre, M

    2017-08-01

    A study was conducted between May 2013 and August 2014 in three provinces of Vietnam to investigate financial impacts of swine diseases in pig holdings in 2010-2013. The aim of the study was to quantify the costs of swine diseases at producer level in order to understand swine disease priority for monitoring at local level. Financial impacts of porcine reproductive and respiratory syndrome (PRRS), foot and mouth disease (FMD), and epidemic diarrhoea were assessed for 162 pig holders in two Red River Delta provinces and in one Mekong River Delta province, using data on pig production and swine disease outbreaks at farms. Losses incurred by swine diseases were estimated, including direct losses due to mortality (100% market value of pig before disease onset) and morbidity (abortion, delay of finishing stage), and indirect losses due to control costs (treatment, improving biosecurity and emergency vaccination) and revenue foregone (lower price in case of emergency selling). Financial impacts of swine diseases were expressed as percentage of gross margin of pig holding. The gross margin varied between pig farming groups (P swine disease priorities to better inform surveillance and control at both national and local level. © 2016 Blackwell Verlag GmbH.

  15. Impacts of 25 years of groundwater extraction on subsidence in the Mekong delta, Vietnam

    Science.gov (United States)

    Many major river deltas in the world are subsiding and consequently become increasingly vulnerable to flooding and storm surges, salinization and permanent inundation. For the Mekong Delta, annual subsidence rates up to several centimetres have been reported. Excessive groundwate...

  16. Biological Observations on the Mudskipper Pseudapocryptes elongatus in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Bucholtz, R. H.; Meilvang, A. S.; Cedhagen, Tomas;

    2009-01-01

    Aspects of the population biology of the mudskipper, Pseudapocryptes elongatus, (Cuvier, 1816) were studied in Bac Lieu Province in the Lower Mekong Delta, Vietnam, including sex ratio, length–frequency distribution, sexual dimorphism, hepatosomatic index (HSI), female gonadosomatic index (GSI...

  17. Absence of knockdown resistance suggests metabolic resistance in the main malaria vectors of the Mekong region

    Directory of Open Access Journals (Sweden)

    Sochantha Tho

    2009-04-01

    Full Text Available Abstract Background As insecticide resistance may jeopardize the successful malaria control programmes in the Mekong region, a large investigation was previously conducted in the Mekong countries to assess the susceptibility of the main malaria vectors against DDT and pyrethroid insecticides. It showed that the main vector, Anopheles epiroticus, was highly pyrethroid-resistant in the Mekong delta, whereas Anopheles minimus sensu lato was pyrethroid-resistant in northern Vietnam. Anopheles dirus sensu stricto showed possible resistance to type II pyrethroids in central Vietnam. Anopheles subpictus was DDT- and pyrethroid-resistant in the Mekong Delta. The present study intends to explore the resistance mechanisms involved. Methods By use of molecular assays and biochemical assays the presence of the two major insecticide resistance mechanisms, knockdown and metabolic resistance, were assessed in the main malaria vectors of the Mekong region. Results Two FRET/MCA assays and one PCR-RFLP were developed to screen a large number of Anopheles populations from the Mekong region for the presence of knockdown resistance (kdr, but no kdr mutation was observed in any of the study species. Biochemical assays suggest an esterase mediated pyrethroid detoxification in An. epiroticus and An. subpictus of the Mekong delta. The DDT resistance in An. subpictus might be conferred to a high GST activity. The pyrethroid resistance in An. minimus s.l. is possibly associated with increased detoxification by esterases and P450 monooxygenases. Conclusion As different metabolic enzyme systems might be responsible for the pyrethroid and DDT resistance in the main vectors, each species may have a different response to alternative insecticides, which might complicate the malaria vector control in the Mekong region.

  18. Valley Fever

    Science.gov (United States)

    ... anything that disrupts the soil, such as farming, construction and wind. The fungi can then be breathed ... expose them to dust are most at risk — construction, road and agricultural workers, ranchers, archeologists, and military ...

  19. Groundwater recharge on east side soils of the Salinas Valley

    Science.gov (United States)

    After four years of drought, groundwater levels in the Salinas Valley are at historically low levels which threaten to adversely affect farming in the Salinas Valley. Given the prospect of a strong El Niño this coming winter, it seems prudent to plan to capture as much of the rainfall as possible to...

  20. Flood trends and variability in the Mekong river

    Directory of Open Access Journals (Sweden)

    J. M. Delgado

    2010-03-01

    Full Text Available Annual maximum discharge is analyzed in the Mekong river in Southeast Asia with regard to trends in average flood and trends in variability during the 20th century. Data from four gauging stations downstream of Vientiane, Laos, were used, covering two distinct hydrological regions within the Mekong basin. These time series span through over 70 years and are the longest daily discharge time series available in the region. The methods used, Mann Kendal test (MK, ordinary least squares with resampling (OLS and non-stationary generalized extreme value function (NSGEV, are first tested in a Monte Carlo experiment, in order to evaluate their detection power in presence of changing variance in the time series. The time series are generated using the generalized extreme value function with varying scale and location parameter. NSGEV outperforms MK and OLS, both because it resulted in less type II errors, but also because it allows for a more complete description of the trends, allowing to separate trends in average and in variability.

    Results from MK, OLS and NSGEV agreed on trends in average flood behaviour. However, the introduction of a time-varying scale parameter in the NSGEV allowed to isolate flood variability from the trend in average flood and to have a more complete view of the changes. Overall, results showed an increasing likelihood of extreme floods during the last half of the century, although the probability of an average flood decreased during the same period. A period of enhanced variance in the last quarter of the 20th century, estimated with the wavelet power spectrum as a function of time, was identified, which confirmed the results of the NSGEV.

    We conclude that the absence of detected positive trends in the hydrological time series was a methodological misconception due to over-simplistic models.

  1. 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.

  2. Farm Team.

    Science.gov (United States)

    Gordon, Debra

    2001-01-01

    Describes a Philadelphia high school in which urban students study agricultural sciences to prepare for college and careers. The campus has a complete working farm, and students are exposed to a wide range of agricultural career opportunities while also studying core academic subjects. The school's farm units are real businesses, so students are…

  3. Enhancing Floodplain Management in the Lower Mekong River Basin Using Vegetation and Water Cycle Satellite Observations

    Science.gov (United States)

    Bolten, J. D.; Spruce, J.; Wilson, R.; Strauch, K.; Doyle, T.; Srinivan, R.; Lakshmi, V.; Gupta, M.

    2014-12-01

    The Lower Mekong River Basin shared by China, Burma, Laos, Thailand, Cambodia, and Vietnam, is considered the lifeblood of Southeast Asia. The Mekong Basin is subject to large hydrological fluctuations on a seasonal and inter-annual basis. The basin remains prone to severe annual floods that continue to cause widespread damage and endanger food security and the livelihood of the millions who dwell in the region. Also the placement of newly planned dams primarily for hydropower in the Lower Mekong Basin may cause damaging social, agriculture and fisheries impacts to the region where we may now likely be at a critical 'tipping point'. The primary goal of this project is to apply NASA and USGS products, tools, and information for improved flood and water management in the Lower Mekong River Basin to help characterize, understand, and predict future changes on the basin. Specifically, we are providing and helping transfer to the Mekong River Commission (MRC) and the member countries of Thailand, Cambodia, Lao, Vietnam, and Burma the enhanced Soil and Water Assessment Tool (SWAT) using remotely sensed surface, ground water, and root zone soil moisture along with improved Land Use and Land Cover (LULC) maps. In order to estimate the flood potential and constrain the SWAT Available Water Capacity model parameter over the region, we are assimilated GRACE Terrestrial Water Storage observations into the Catchment Land Surface Model. In addition, a Graphic Visualization Tool (GVT) as been developed to work in concert with the output of the SWAT model parameterized for the Mekong Basin as an adjunct tool of the MRC Decision Support Framework. The project requires a close coordination of the development and assessment of the enhanced MRC SWAT with the guidance of MRC resource managers and technical advisors. This presentation will evaluate the skill of the enhanced SWAT model using qualitative (i.e., MODIS change detection) and quantitative (e.g., streamflow) metrics over one

  4. Improving sustainability of striped catfish (Pangasianodon hypophthalmus) farming in the Mekong Delta, Vietnam through recirculation technology

    NARCIS (Netherlands)

    Nguyen, Nhut

    2016-01-01

    The aim of this thesis was to document improvements in sustainability indicators of striped catfish (Pangasianodon hypophthalmus, Sauvage, 1878) production through the application of recirculation and waste treatment techniques. To be able to document improvements in sustainability, in each system s

  5. 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.

  6. Ecological health monitoring of the Mekong River by using benthic algae in 2003-2004

    Science.gov (United States)

    Kunpradid, T.

    2005-05-01

    The monitoring of ecological health of the Mekong River by using benthic algae was carried out from 2003 - 2004. Thirty sampling sites along the Mekong River and its tributaries were selected in Laos, Thailand, Cambodia and Veitnam. In this investigation, the distribution of some species of benthic algae in different environments revealed that there was a significant relationship in the presence of them to the water quality, and these species could be used as a potential biomonitor of water quality in the Mekong River. One hundred and eighty six species of benthic diatoms and 46 species of macroalgae were found. Some dominant species of benthic algae could be used as biomonitors to assess water quality. Hydrodictyon recticulatum and Microspora floccosa and indicated clean-moderate water quality; Audouinella cylindrica, Cladophora glomerata, Achnanthes inflate and Cymbella turgidula indicated moderate water quality; Stigeoclonium flagelliforum, Aulacoseira granulata and Cymbella tumida indicated moderate-polluted water quality and Caloglossa leprieurii, Gomphonema parvulum and Nitzschia clausii indicated polluted water quality. The ecological health assessment of the Mekong River by using the species of benthic algae as biomonitors reveled that in the upstream and tributaries revealed moderate water quality. In contrast, some sites in the lower Mekong showed moderate-polluted to polluted water quality.

  7. Sediment dynamics in the Mekong basin- a multi-objective calibration on discharge and sediment load

    Science.gov (United States)

    Luedtke, Stefan; Apel, Heiko; Viet Dung, Nguyen; Merz, Bruno

    2013-04-01

    The Mekong delta is one of the most extensively used deltas world wide and provides natural resources to more than 17 million people. Environmental issues in the Mekong delta are closely linked to water usage and availability. In addition, the sediment input to the floodplains during the annual flood plays a crucial role in terms of nutrient supply to agriculture. Since flood magnitudes and sediment delivery are driven by human activities and hydrological processes along the entire Mekong river, it is highly important to assess the dynamics upstream of the Mekong delta. This study applies the hydrological model SWIM to the watershed upstream of Kratie/Cambodia with a size of approximately 650.000 km2 and gives a quantitative depiction on the sediment and discharge dynamics. The model is driven by different, mostly globally available data sources. After the identification of the sensitive parameters, a multi objective calibration, namely the NSGA-II algorithm, is applied. The model simulates the discharge values well, e.g. by capturing the annual flood season and sediment dynamics. The next steps comprise an assessment of different sources of uncertainty that are incorporated in the model. This includes the climate input data and the sparsely available and highly variable sediment data. Eventually, the study shall provide a basis to examine the future developments along the Mekong river, for example, quantifying the impacts of potential reservoirs on the flow regime and sediment dynamics.

  8. Intraspecific diversity of Edwardsiella ictaluri isolates from diseased freshwater catfish, Pangasianodon hypophthalmus (Sauvage), cultured in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Bartie, K L; Austin, F W; Diab, A; Dickson, C; Dung, T T; Giacomini, M; Crumlish, M

    2012-09-01

    A molecular epidemiology study was conducted on 90 Edwardsiella ictaluri isolates recovered from diseased farmed freshwater catfish, Pangasianodon hypophthalmus, cultured in the Mekong Delta, Vietnam. Thirteen isolates of E. ictaluri derived from diseased channel catfish, Ictalurus punctatus, cultured in the USA were included for comparison. All the E.ictaluri isolates tested were found to be biochemically indistinguishable. A repetitive (rep)-PCR using the single (GTG)(5) primer was shown to possess limited discriminatory power, yielding two similar DNA profiles categorized as (GTG)(5) -PCR group 1 or 2 among the Vietnam isolates and (GTG)(5) -PCR group 1 within the USA isolates. Macrorestriction analysis identified 14 and 22 unique pulsotypes by XbaI and SpeI, respectively, among a subset of 59 E. ictaluri isolates. Numerical analysis of the combined macrorestriction profiles revealed three main groups: a distinct cluster formed exclusively of the USA isolates, and a major and minor cluster with outliers contained the Vietnam isolates. Antibiotic susceptibility and plasmid profiling supported the existence of the three groups. The results indicate that macrorestriction analysis may be regarded as a suitable typing method among the E. ictaluri species of limited intraspecific diversity. Furthermore, the findings suggest that E. ictaluri originating from Vietnam may constitute a distinct genetic group.

  9. Farm Animals

    Science.gov (United States)

    ... same bacterium that has become resistant to certain antibiotics, which can make infections harder to treat. MRSA can be passed back and forth between people and farm animals through direct contact. In humans, MRSA can cause ...

  10. 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

  11. A Study on applying the Catfish Biofuel in The Mekong Delta for The Marine Diesel Engine

    Directory of Open Access Journals (Sweden)

    Phan Văn Quân

    2015-12-01

    Full Text Available The manufacturing of Catfish products has been developed rapidly in the Mekong delta. Every year, about 1.2 million tons of Catfish and 150,000 tons of biofuel are produced. The biofuel B100 manufactures in Mekong delta satisfies the America standard ASTM D6751; EURO EN 14214 or Vietnamese standard TCVN 7717. Mekong delta, a lower land area, has a large inland water way system with around 100.000 river boats that operate with marine diesel engine. Using the biofuel for the marine diesel engine in area will reduce the HC, CO, SOx and NOx emission to the environment. Therefore, with a study on applying the catfish biofuel, it will reduce the climate change by the increasing of sea water level and save energy by using green energy to replace petrol oil.

  12. Epidemiology of Strongyloides stercoralis on Mekong islands in southern Laos.

    Science.gov (United States)

    Vonghachack, Youthanavanh; Sayasone, Somphou; Bouakhasith, Dalouny; Taisayavong, Keoka; Akkavong, Kongsap; Odermatt, Peter

    2015-01-01

    Strongyloides stercoralis is a neglected helminth infection potentially that can lead to systemic infection in immunocompromised individuals. In Lao People's Democratic Republic (Lao PDR, Laos), information on S. stercoralis infection is scarce. We assessed S. stercoralis infection and associated risk factors and symptoms on the Mekong islands in Southern Laos. Baermann and Kato-Katz techniques were performed on two stool samples from each individual to detect S. stercoralis larvae and concomitant helminth infections. Among 729 individuals, 41.0% were infected with S. stercoralis. Men were at higher risk than women (OR 1.97, 95% CI 1.45-2.67). Urticaria and body itching was associated with S. stercoralis infection (OR 2.4, 95% CI 1.42-4.05). Infection with Opisthorchis viverrini (72.2%), Schistosoma mekongi (12.8%), and hookworm (56.1%) were very common. Few infections with Trichuris trichiura (3.3%), Ascaris lumbricoides (0.3%) and Taenia spp. (0.3%) were detected. The majority of helminth infections were of light intensity, with prevalences of 80.4%, 92.9%, 64.5%, 100% and 100%, for O. viverrini, hookworm, S. mekongi, T. trichiura and A. lumbricoides, respectively. Nevertheless, heavy infection intensities were observed for O. viverrini (1.0%), S. mekongi (14.0%) and hookworm (2.9%). S. stercoralis is highly endemic on the islands of Khong district, Champasack province, Southern Laos. The national helminth control programme should take action to control this helminth infection.

  13. Farm Tourism

    DEFF Research Database (Denmark)

    Blichfeldt, Bodil Stilling; Nielsen, Niels Christian; Nissen, Kathrine Aae

    2011-01-01

    This paper draws on a study of one specific type of small tourism enterprises (i.e. farm tourism enterprises) and argues that these enterprises differ from other enterprises in relation to a series of issues other than merely size. The analysis shows that enterprises such as these are characterized...... by blurriness of boundaries between „home spheres‟ and work situations as well as by a unique blend of commercial and private hospitality. Furthermore, the study shows that „social‟ motivations and non-monetary benefits gained through host-guest interactions are of great importance to the hosts. In particular......, our study suggests that it is problematic to threat farm tourism enterprises as if they have much in common with both larger corporations and other types of SMTEs. Farm tourism enterprises seem to differ significantly from other enterprises as the hosts are not in the tourism business because...

  14. Ant Farm

    OpenAIRE

    2012-01-01

    Publié à l’occasion de l’exposition d’Ant Farm au Frac Centre du 12 au 23 décembre 2007, ce très beau catalogue, qui fait état des dix ans de création du collectif californien, propose un nombre important de documents iconographiques, de notices et de textes concernant leurs différents projets. Fondé en 1968 par Doug Michels et Chip Lord, rejoints par la suite par Curtis Schreier, Hudson Marquez, Douglas Hurr et d’autres encore, le collectif Ant Farm a marqué les esprits par quelques œuvres s...

  15. The Central Valley Hydrologic Model

    Science.gov (United States)

    Faunt, C.; Belitz, K.; Hanson, R. T.

    2009-12-01

    Historically, California’s Central Valley has been one of the most productive agricultural regions in the world. The Central Valley also is rapidly becoming an important area for California’s expanding urban population. In response to this competition for water, a number of water-related issues have gained prominence: conjunctive use, artificial recharge, hydrologic implications of land-use change, subsidence, and effects of climate variability. To provide information to stakeholders addressing these issues, the USGS made a detailed assessment of the Central Valley aquifer system that includes the present status of water resources and how these resources have changed over time. The principal product of this assessment is a tool, referred to as the Central Valley Hydrologic Model (CVHM), that simulates surface-water flows, groundwater flows, and land subsidence in response to stresses from human uses and from climate variability throughout the entire Central Valley. The CVHM utilizes MODFLOW combined with a new tool called “Farm Process” to simulate groundwater and surface-water flow, irrigated agriculture, land subsidence, and other key processes in the Central Valley on a monthly basis. This model was discretized horizontally into 20,000 1-mi2 cells and vertically into 10 layers ranging in thickness from 50 feet at the land surface to 750 feet at depth. A texture model constructed by using data from more than 8,500 drillers’ logs was used to estimate hydraulic properties. Unmetered pumpage and surface-water deliveries for 21 water-balance regions were simulated with the Farm Process. Model results indicate that human activities, predominately surface-water deliveries and groundwater pumping for irrigated agriculture, have dramatically influenced the hydrology of the Central Valley. These human activities have increased flow though the aquifer system by about a factor of six compared to pre-development conditions. The simulated hydrology reflects spatial

  16. National Farm Medicine Center

    Science.gov (United States)

    Research Areas Applied Sciences Biomedical Informatics Clinical Research Epidemiology Farm Medicine Human Genetics Oral-Systemic Health Clinical ... Consulting Agritourism Farm MAPPER Lyme Disease ROPS Rebate Zika Virus National Farm Medicine Center The National Farm ...

  17. 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

  18. 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.

  19. High and low value fish chains in the Mekong Delta: challenges for livelihoods and governance

    NARCIS (Netherlands)

    Vo Thi Thanh Loc,; Bush, S.R.; Xuan Sinh, Le; Nguyen Tri Khiem,

    2010-01-01

    This paper investigates the structure, function and wealth distribution within the Pangasius hypophthalmus and Henicorhynchus spp./Labiobarbus spp. value chains in the Mekong Delta of Vietnam. The analysis is driven by key questions relating to the form and function of value chains, their contributi

  20. A political economy of environmental impact assessment in the Mekong region

    Directory of Open Access Journals (Sweden)

    Andrew Wells-Dang

    2016-02-01

    Full Text Available Environmental Impact Assessment (EIA is an issue of concern to governments, organized civil society groups, as well as business actors in the Mekong region. EIA and related forms of environmental assessments are being carried out throughout the region with varying levels of quality, legal frameworks, monitoring and compliance. Through a political economy approach, we seek to understand the interests and incentives among key stakeholders in each of the five Mekong region countries and propose ways that EIA processes can potentially be improved, with reference to hydropower and other infrastructure and development projects. The analysis is based on a collaborative research process carried out under the auspices of the Mekong Partnership for the Environment, a USAID-funded program implemented by Pact that aims to advance regional cooperation on environmental governance. We find that at present, EIA implementation is limited by numerous political economy constraints, some general across the Mekong region, others specific to one or more country contexts. Certain of these constraints can be addressed through a regional cooperative approach, while others will require longer-term changes in social and political dynamics to encourage uptake and impact and avoid possible blockage from entrenched interest groups.

  1. A study of the climate change impacts on fluvial flood propagation in the Vietnamese Mekong Delta

    NARCIS (Netherlands)

    Van, P.D.T.; Popescu, I.; Van Griensven, A.; Solomatine, D.P.; Trung, N.H.; Green, A.

    2012-01-01

    The present paper investigated the extent of the flood propagation in the Vietnamese Mekong Delta under different projected flood hydrographs, considering the 2000 flood event (the 20-yr return period event, T. V. H. Le et al., 2007) as the basis for computation. The analysis herein was done to demo

  2. Assessment of persistent organic pollutants in sediments from Lower Mekong River Basin.

    Science.gov (United States)

    Sudaryanto, Agus; Isobe, Tomohiko; Takahashi, Shin; Tanabe, Shinsuke

    2011-01-01

    Organochlorine compounds (OCs) in sediments collected from various locations in Lower Mekong River Basin (MRB) in Laos and Thailand were examined to elucidate their occurrence, distribution and potential ecological risk. Concentration of PCBs and DDTs were higher than other OCs, ranging from 0.18 to 310μgkg(-1) dry wt. and from 0.027 to 52μgkg(-1) dry wt., respectively, whereas CHLs, HCHs and HCB were 1-3 orders of magnitude lower. Geographical distribution indicates that levels of PCBs, DDTs and CHLs in the Vientiane canal were significantly higher than those in mainstream of Mekong River, Phong River and its surrounding areas, indicating significant sources of these compounds in urbanized areas. Comparison with other parts of MRB indicates that PCBs were higher in Laos, whereas DDTs were more prevalent in Mekong Delta, indicating location specific contaminations of these compounds in MRB. The ratios of DDTs composition indicate possible difference in the historical input of DDT among locations in and around Mekong River. Hazard assessment of PCBs and DDTs indicate possible toxic potential particularly in areas close to point sources such as intensive human activities and agricultural areas which highlight the need for further study.

  3. 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 seed-bo

  4. Amaranth farming

    DEFF Research Database (Denmark)

    Bjarklev, Araceli; Kjær, Tyge; Kjærgård, Bente

    2008-01-01

    natural resources that small-scale farmers have to combat the abovementioned problems. The study identified several local and regional barriers for increasing the level of farming, production, processing and consumption. A striking and paradoxical limitation is the monopolization practices developed...... by some of the associations in relation to knowledge and technology transfer, seeds distribution and contact to potential national and foreign buyers....

  5. Molecular farming

    NARCIS (Netherlands)

    Merck, K.B.; Vereijken, J.M.

    2006-01-01

    Molecular Farming is a new and emerging technology that promises relatively cheap and flexible production of large quantities of pharmaceuticals in genetically modified plants. Many stakeholders are involved in the production of pharmaceuticals in plants, which complicates the discussion on the poss

  6. Forecasting the Cumulative Impacts of Dams on the Mekong Delta: Certainties and Uncertainties

    Science.gov (United States)

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

    2016-12-01

    The Mekong River basin is undergoing rapid hydroelectric development, with 7 large mainstem dams on the upper Mekong (Lancang) River in China and 133 dams planned for the Lower Mekong River basin (Laos, Cambodia, Thailand, Vietnam), 11 of which are on the mainstem. Prior analyses have shown that all these dams built as initially proposed would trap 96% of the natural sediment load to the Mekong Delta. Such a reduction in sediment supply would compromise the sustainability of the delta itself, but there are many uncertainties in the timing and pattern of land loss. The river will first erode in-channel sediment deposits, partly compensating for upstream sediment trapping until these deposits are exhausted. Other complicating factors include basin-wide accelerated land-use change, road construction, instream sand mining, dyking-off floodplains, and changing climate, accelerated subsidence from groundwater extraction, and sea level rise. It is certain that the Mekong Delta will undergo large changes in the coming decades, changes that will threaten its very existence. However, the multiplicity of compounding drivers and lack of good data lead to large uncertainties in forecasting changes in the sediment balance on the scale of a very large network. We quantify uncertainties in available data and consider changes due to additional, poorly quantified drivers (e.g., road construction), putting these drivers in perspective with the overall sediment budget. We developed a set of most-likely scenarios and their implications for the delta's future. Uncertainties are large, but there are certainties about the delta's future. If its sediment supply is nearly completely cut off (as would be the case with `business-as-usual' ongoing dam construction and sediment extraction), the Delta is certainly doomed to disappear in the face of rising seas, subsidence, and coastal erosion. The uncertainty is only when and how precisely the loss will progress.

  7. 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.

  8. Phylogeography of the Mekong mud snake (Enhydris subtaeniata): the biogeographic importance of dynamic river drainages and fluctuating sea levels for semiaquatic taxa in Indochina.

    Science.gov (United States)

    Lukoschek, Vimoksalehi; Osterhage, Jennifer L; Karns, Daryl R; Murphy, John C; Voris, Harold K

    2011-11-01

    During the Cenozoic, Southeast Asia was profoundly affected by plate tectonic events, dynamic river systems, fluctuating sea levels, shifting coastlines, and climatic variation, which have influenced the ecological and evolutionary trajectories of the Southeast Asian flora and fauna. We examined the role of these paleogeographic factors on shaping phylogeographic patterns focusing on a species of semiaquatic snake, Enhydris subtaeniata (Serpentes: Homalopsidae) using sequence data from three mitochondrial fragments (cytochrome b, ND4, and ATPase-2785 bp). We sampled E. subtaeniata from seven locations in three river drainage basins that encompassed most of this species' range. Genetic diversities were typically low within locations but high across locations. Moreover, each location had a unique suite of haplotypes not shared among locations, and pairwise φ(ST) values (0.713-0.998) were highly significant between all location pairs. Relationships among phylogroups were well resolved and analysis of molecular variance (AMOVA) revealed strong geographical partitioning of genetic variance among the three river drainage basins surveyed. The genetic differences observed among the populations of E. subtaeniata were likely shaped by the Quaternary landscapes of Indochina and the Sunda Shelf. Historically, the middle and lower Mekong consisted of strongly dissected river valleys separated by low mountain ranges and much of the Sunda Shelf consisted of lowland river valleys that served to connect faunas associated with major regional rivers. It is thus likely that the contemporary genetic patterns observed among populations of E. subtaeniata are the result of their histories in a complex terrain that created abundant opportunities for genetic isolation and divergence yet also provided lowland connections across now drowned river valleys.

  9. Amaranth farming

    DEFF Research Database (Denmark)

    Bjarklev, Araceli; Kjær, Tyge; Kjærgård, Bente

    2008-01-01

    Though amaranth has been studied intensively for its exceptional nutritional properties, little has been reported about its capacity for fighting poverty, securing food supplies, turning migrations, or its impact on the environment and the prospect for mprovement of living conditions of those...... natural resources that small-scale farmers have to combat the abovementioned problems. The study identified several local and regional barriers for increasing the level of farming, production, processing and consumption. A striking and paradoxical limitation is the monopolization practices developed...

  10. Health equity and migrants in the Greater Mekong Subregion

    Science.gov (United States)

    McMichael, Celia; Healy, Judith

    2017-01-01

    ABSTRACT Background: Migrant health is receiving increasing international attention, reflecting recognition of the health inequities experienced among many migrant populations and the need for health systems to adapt to diverse migrant populations. In the Greater Mekong Subregion (GMS) there is increasing migration associated with uneven economic integration and growth, socio-economic vulnerabilities, and disparities between countries. There has been limited progress, however, in improving migrant access to health services in the Subregion. This paper examines the health needs, access barriers, and policy responses to cross-border migrants in five GMS countries. Methods: A review of published literature and research was conducted on migrant health and health service access in Cambodia, Lao People’s Democratic Republic, Myanmar, Thailand, and Viet Nam, as well as analysis of current migration trends and universal health coverage (UHC) indicators in the Subregion. The review included different migrant types: i.e. migrant workers, irregular migrants, victims of trafficking, refugees and asylum seekers, and casual cross-border migrants. Results: There is substantial diversity in the capacity of GMS health systems to address migrant populations. Thailand has sought to enhance migrant health coverage, including development of migrant health policies/programs, bilateral migrant worker agreements, and migrant health insurance schemes; Viet Nam provides health protection for emigrant workers. Overall, however, access to good quality health care remains weak for many citizens in GMS countries let alone migrants. Migrant workers – and irregular migrants in particular – face elevated health risks yet are not adequately covered and incur high out-of-pocket (OOP) payments for health services. Conclusions: UHC implies equity: UHC is only achieved when everyone has the opportunity to access and use good-quality health care. Efforts to achieve UHC in the GMS require

  11. Experiment on an Integrated Ricefish Polyculture System (6 Species, 1- 2 fish/m2 in the Mekong Delta

    Directory of Open Access Journals (Sweden)

    Lan, LM.

    2002-01-01

    Full Text Available Our ricefish polyculture (6 species results at two stocking densities (1 and 2 fish/m2 show that: The water quality in a ricefish polyculture system, such as water temperature (29.1 – 29.0 °C, water pH (6.6 – 6.7, water transparency (18.0 – 20.8 cm, dissolved O2 (4.7 – 4.6 ppm, CO2 (22.8 – 23.1 ppm, COD (11.9 – 12.7 ppm, are similar at both densities and acceptable for the 6 tropical fish species. Ammonium and phosphorus concentrations are statistically higher at 1 fish/m2 (0.4 and 0.2 ppm. The primary productivity is similar for both densities (6.5 – 6.8 g O2/m3/day and suitable for fish culture. The phytoplankton biodiversity is relatively high and at the same level for both treatments (74 – 63 taxa, but the densities of phytoplankton, of zooplankton, and the biomass of zoobenthos are lower at the highest density (2 fish/m2, probably due to a higher predation by fish.The fish yield (808 kg/ha at 2 fish/m2 is higher than at 1 fish/m2 (482 kg/ha. The cost ratio benefit (1.84 and the cost ratio profit (1.81 for farm households at 1 fish/m2 are lower than those values at 2 fish/m2 (2.1 and 2.05 respectively. Regarding the aquaculture extension program, the model of the ricefish polyculture (6 species system with the stocking density of 2 fish/m2 could be extended in the rice fields to improve farmer's income in the Mekong delta.

  12. 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

  13. Rodents and risk in the Mekong Delta of Vietnam: seroprevalence of selected zoonotic viruses in rodents and humans.

    Science.gov (United States)

    Van Cuong, Nguyen; Carrique-Mas, Juan; Vo Be, Hien; An, Nguyen Ngoc; Tue, Ngo Tri; Anh, Nguyet Lam; Anh, Pham Hong; Phuc, Nguyen The; Baker, Stephen; Voutilainen, Liina; Jääskeläinen, Anne; Huhtamo, Eili; Utriainen, Mira; Sironen, Tarja; Vaheri, Antti; Henttonen, Heikki; Vapalahti, Olli; Chaval, Yannick; Morand, Serge; Bryant, Juliet E

    2015-01-01

    In the Mekong Delta in southern Vietnam, rats are commonly traded in wet markets and sold live for food consumption. We investigated seroprevalence to selected groups of rodent-borne viruses among human populations with high levels of animal exposure and among co-located rodent populations. The indirect fluorescence antibody test (IFAT) was used to determine seropositivity to representative reference strains of hantaviruses (Dobrava virus [DOBV], Seoul virus [SEOV]), cowpox virus, arenaviruses (lymphocytic choriomeningitis virus [LCMV]), flaviviruses (tick-borne encephalitis virus [TBEV]), and rodent parechoviruses (Ljungan virus), using sera from 245 humans living in Dong Thap Province and 275 rodents representing the five common rodent species sold in wet markets and present in peridomestic and farm settings. Combined seropositivity to DOBV and SEOV among the rodents and humans was 6.9% (19/275) and 3.7% (9/245), respectively; 1.1% (3/275) and 4.5% (11/245) to cowpox virus; 5.4% (15/275) and 47.3% (116/245) for TBEV; and exposure to Ljungan virus was 18.8% (46/245) in humans, but 0% in rodents. Very little seroreactivity was observed to LCMV in either rodents (1/275, 0.4%) or humans (2/245, 0.8%). Molecular screening of rodent liver tissues using consensus primers for flaviviruses did not yield any amplicons, whereas molecular screening of rodent lung tissues for hantavirus yielded one hantavirus sequence (SEOV). In summary, these results indicate low to moderate levels of endemic hantavirus circulation, possible circulation of a flavivirus in rodent reservoirs, and the first available data on human exposures to parechoviruses in Vietnam. Although the current evidence suggests only limited exposure of humans to known rodent-borne diseases, further research is warranted to assess public health implications of the rodent trade.

  14. Valley precession and valley polarization in graphene with inter-valley coupling

    Science.gov (United States)

    Wu, Qing-Ping; Liu, Zheng-Fang; Chen, Ai-Xi; Xiao, Xian-Bo; Zhang, Heng; Miao, Guo-Xing

    2017-10-01

    We theoretically investigate the valley precession and valley polarization in graphene under inter-valley coupling. Our results show that the inter-valley coupling can induce valley polarization in graphene and also precess valleys in real space in a manner similar to the Rashba spin-orbit interaction rotating spins. Moreover, using strain modulation, we can achieve high valley polarization with large valley-polarized currents. These findings provide a new way to create and manipulate valley polarization in graphene.

  15. Hybrid Fv - Biogas/Diesel System Measuring With Homer. Case of Application: Farm Pozo Verde, Jamundi Municipality, Cauca Valley, Colombia; Dimensionado de un Sistema Hibrido Fv - Biogas/Diesel mediante el Empleo de la Herramienta Homer. Caso de Aplicacion: Granja Pozo Verde, Municipio de Jamundi, Valle del Cauca, Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, J.; Manrique, P. A.; Pinedo, I.

    2009-11-25

    This report completes the previous one, by adding the characterization of renewable energy systems based on optimization and sizing tools. A case study has been carried out in the Valley of Cauca (Colombia) using HOMER, once the solar energy potential was defined. This work is about the production of electricity using hybrid power systems (HPS). The HPS chosen for this study is based on two of the most common energy resources in most of Colombian rural areas: solar energy and biomass waste. The biomass waste is obtained by animal manure from livestock farms, particularly from pigs, which is highly valued in terms of energy production. The breeding of pigs has a huge economic, environmental and social importance in this Colombian region. In this report, the HPS technology and the energy contribution of the biogas produced from animal manure are described. A technical and economic simulation of a HPS has been performed using the optimization tool HOMER. These reports are the result of a collaboration established between Universidad del Valle (Colombia) and CIEMAT (Spain), and have been done by the author while his staying at our center included on his PhD program. Keywords: renewable energies, hybrid systems, biogas, technology sizing, rural electrification, Latin America. (Author) 8 refs.

  16. 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

  17. Fish Migration, Dams, and Loss of Ecosystem Services in the Mekong Basin

    Energy Technology Data Exchange (ETDEWEB)

    Dugan, Patrick J. [WorldFish Center; Barlow, Chris [Australian Center for International Agricultural Research (ACIAR); Agostinho, Angelo A. [Fundacao University, Parana Brazil; Baran, Eric [WorldFish Center; Cada, Glenn F [ORNL; Chen, Daqing [Yangtze River Fisheries Research Institute, People' s Republic of China; Cowx, Ian G. [Hull International Fisheries Research Institute, England; Ferguson, John W. [North West Fisheries Science Center, Seattle, WA; Jutagate, Tuantong [Ubon Ratchathani University, Ubon Ratchathani, Thailand; Mallen-Cooper, Martin [Fishway Consulting Service, Australia; Marmulla, Gerd [Food and Agriculture Organization of the United Nations (FAO), Rome, Italy; Nestler, John [USA Corps Engineers, Concord, MA USA; Petrere, Miquel [Universidade Estadual Paulista, Rio Claro, Brazil; Winemiller, Kirk O. [Texas A& M University

    2010-06-01

    The past decade has seen increased international recognition of the importance of the services provided by natural ecosystems. It is unclear however whether such international awareness will lead to improved environmental management in many regions. We explore this issue by examining the specific case of fish migration and dams on the Mekong river. We determine that dams on the Mekong mainstem and major tributaries will have a major impact on the basin's fisheries and the people who depend upon them for food and income. We find no evidence that current moves towards dam construction will stop, and consider two scenarios for the future of the fisheries and other ecosystems of the basin. We conclude that major investment is required in innovative technology to reduce the loss of ecosystem services, and alternative livelihood strategies to cope with the losses that do occur

  18. 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.

  19. 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.

  20. Exploring the climate change concerns of striped catfish producers in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Nguyen, Anh Lam; Truong, Minh Hoang; Verreth, Johan Aj; Leemans, Rik; Bosma, Roel H; De Silva, Sena S

    2015-01-01

    This study investigated the perceptions on and adaptations to climate change impacts of 235 pangasius farmers in the Mekong Delta, Vietnam. Data were collected using semi-structured household surveys in six provinces, from three regions along the Mekong river branches. A Chi-Square test was used to determine the association between variables, and a logit regression model was employed to identify factors correlated with farmer's perception and adaptation. Less than half of respondents were concerned about climate change and sought suitable adaptation measures to alleviate its impacts. Improving information on climate change and introducing early warning systems could improve the adaptive capacity of pangasius farmers, in particularly for those farmers, who were not concerned yet. Farmers relied strongly on technical support from government agencies, but farmers in the coastal provinces did not express the need for training by these institutions. This contrasting result requires further assessment of the effectiveness of adaptation measures such as breeding salinity tolerant pangasius.

  1. A multi-biomarker approach to assess the impact of farming systems on black tiger shrimp (Penaeus monodon).

    Science.gov (United States)

    Tu, Huynh Thi; Silvestre, Frederic; Wang, Neil; Thome, Jean-Pierre; Phuong, Nguyen Thanh; Kestemont, Patrick

    2010-11-01

    This study examined the advantages of the use of biomarkers as an early warning system by applying it to different shrimp farming systems in Soctrang and Camau provinces, main shrimp producers in Mekong River Delta, Vietnam. Shrimp were collected at 15 different farms divided into four different farming systems: three farms were converted from originally rice paddies into intensive shrimp farming systems (IS1, IS2, IS3); three farms were rice-shrimp integrated farming systems (RS4, RS5, RS6); three farms were intensive farming systems (IS7, IS8, IS9); six farms were extensive shrimp farming systems (From ES1 to ES6). Lipid peroxidation (LPO) and total glutathione (GSH) were measured as well as catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST) and acetylcholinesterase activities (ACHE). Organ specificity was observed between gills and hepatopancreas with generally higher activity of GST in gills (GSTG) whereas the contrary was observed for LPO level in gills (LPOG). Hierarchical clustering and principal component analysis clearly indicated that shrimp reared in extensive culture system formed a distinct group from those reared in intensive or rice-shrimp integrated systems. CAT in gills (CATG), GPX in gills (GPXG) and hepatopancreas (GPXHP) and ACHE in muscle (ACHEM) of shrimp collected in extensive farms showed a general higher level than those in intensively farmed shrimp. On the contrary, we observed clear high levels of GSTG and GST in hepatopancreas (GSTHP) and LPOG and hepatopancreas (LPOHP) of shrimp sampled in intensive and rice-shrimp integrated systems. Thus, we propose that LPO and CAT, GPX, GST and ACHE can be used as a set of biomarkers for the assessment of health condition and can discriminate between shrimp cultivated in different farming systems. These findings provide the usefulness of integrating a set of biomarkers to define the health status of shrimp in different shrimp culture systems.

  2. Energy valley in transition

    NARCIS (Netherlands)

    Verwayen, Barbara

    2006-01-01

    The Energy Valley foundation was born in 2004. It functions as a catalyst and platform for private and public organisations. It has a supporting and facilitating role in realising projects on energy conservation and sustainable energy. The Energy Valley a

  3. Association between climate factors and diarrhoea in a Mekong Delta area

    Science.gov (United States)

    Phung, Dung; Huang, Cunrui; Rutherford, Shannon; Chu, Cordia; Wang, Xiaoming; Nguyen, Minh; Nguyen, Nga Huy; Manh, Cuong Do; Nguyen, Trung Hieu

    2015-09-01

    The Mekong Delta is vulnerable to changes in climate and hydrological events which alter environmental conditions, resulting in increased risk of waterborne diseases. Research exploring the association between climate factors and diarrhoea, the most frequent waterborne disease in Mekong Delta region, is sparse. This study evaluated the climate-diarrhoea association in Can Tho city, a typical Mekong Delta area in Vietnam. Climate data (temperature, relative humidity, and rainfall) were obtained from the Southern Regional Hydro-Meteorological Centre, and weekly counts of diarrhoea visits were obtained from Can Tho Preventive Medicine Centre from 2004 to 2011. Analysis of climate and health variables was carried out using spline function to adjust for seasonal and long-term trends of variables. A distributed lag model was used to investigate possible delayed effects of climate variables on diarrhoea (considering 0-4 week lag periods), then the multivariate Poisson regression was used to examine any potential association between climate factors and diarrhoea. The results indicated that the diarrhoea incidence peaked within the period August-October annually. Significant positive associations were found between increased diarrhoea and high temperature at 4 weeks prior to the date of hospital visits (IRR = 1.07; 95 % CI = 1.04-1.08), high relative humidity (IRR = 1.13; 95 % CI = 1.12-1.15) and high (>90th percentile) cumulative rainfall (IRR = 1.05; 95 % CI = 1.05-1.08). The association between climate factors and diarrhoea was stronger in rural than urban areas. These findings in the context of the projected changes of climate conditions suggest that climate change will have important implications for residential health in Mekong Delta region.

  4. Large-scale quantification of suspended sediment transport and deposition in the Mekong Delta

    Directory of Open Access Journals (Sweden)

    N. V. Manh

    2014-04-01

    Full Text Available Sediment dynamics play a major role for the agricultural and fishery productivity of the Mekong Delta. However, the understanding of sediment dynamics in the Mekong Delta, one of the most complex river deltas in the world, is very limited. This is a consequence of its large extent, the intricate system of rivers, channels and floodplains and the scarcity of observations. This study quantifies, for the first time, the suspended sediment transport and sediment-nutrient deposition in the whole Mekong Delta. To this end, a quasi-2-D hydrodynamic model is combined with a cohesive sediment transport model. The combined model is calibrated automatically using six objective functions to represent the different aspects of the hydraulic and sediment transport components. The model is calibrated for the extreme flood season in 2011 and shows good performance for the two validation years with very different flood characteristics. It is shown how sediment transport and sediment deposition vary from Kratie at the entrance of the Delta to the coast. The main factors influencing the spatial sediment dynamics are the setup of rivers, channels and dike-rings, the sluice gate operations, the magnitude of the floods and tidal influences. The superposition of these factors leads to high spatial variability of sediment transport, in particular in the Vietnamese floodplains. Depending on the flood magnitude, the annual sedimentation rate averaged over the Vietnamese floodplains varies from 0.3 to 2.1 kg m−2 yr−1, and the ring dike floodplains trap between 1 and 6% of the total sediment load at Kratie. This is equivalent to 29 × 103–440 × 103 t of nutrients (N, P, K, TOC deposited in the Vietnamese floodplains. This large-scale quantification provides a basis for estimating the benefits of the annual Mekong floods for agriculture and fishery, and is important information for assessing the effects of deltaic subsidence and climate change related sea level rise.

  5. Climate Issue and China in U.S.Mekong River Policy

    Institute of Scientific and Technical Information of China (English)

    Li; Zhifei

    2014-01-01

    <正>Since taking office in 2009,the Obama administration has much-touted"pivot"to Asia policy,strengthened the U.S.regional leadership and policy coordination of the trans-Pacific order,and taken Southeast Asia the new fulcrum of its strategic operations and the Lower Mekong Region a vital flank of its new Asia-Pacific strategy.During a Congressional Hearing in

  6. Biological Observations on the Mudskipper Pseudapocryptes elongatus in the Mekong Delta, Vietnam

    DEFF Research Database (Denmark)

    Bucholtz, R. H.; Meilvang, A. S.; Cedhagen, Tomas

    2009-01-01

    Aspects of the population biology of the mudskipper, Pseudapocryptes elongatus, (Cuvier, 1816) were studied in Bac Lieu Province in the Lower Mekong Delta, Vietnam, including sex ratio, length–frequency distribution, sexual dimorphism, hepatosomatic index (HSI), female gonadosomatic index (GSI), ...... in salinities ranging from freshwater to 50 ppt. Gut content analysis revealed that P. elongatus is a herbivore, feeding mainly on pennate diatoms (93% of the diet)....

  7. 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.

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

    OpenAIRE

    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 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 Mekon...

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Impact of the Mekong River flow alteration on the Tonle Sap flood pulse.

    Science.gov (United States)

    Kummu, Matti; Sarkkula, Juha

    2008-05-01

    Rapid development in the upper reaches of the Mekong River, in the form of construction of large hydropower dams and reservoirs, large irrigation schemes, and rapid urban development, is putting water resources under stress. Recent studies have concluded that these developments will lead to flow alterations in the Mekong River. These flow alterations would threaten the sensitive ecosystems downstream, particularly Tonle Sap River, Tonle Sap Lake, its floodplain, and its gallery forest and protected areas, by changing the flood-pulse system of the lake. This article estimates the changes in parameters of the Tonle Sap flood pulse due to the aforementioned flow alterations. The impacts on the flooded area and loss of gallery forest and protected areas were analyzed using geographic information system-based methods. Relatively small rises in the dry-season lake water level would permanently inundate disproportionately large areas of floodplain, rendering it inaccessible to floodplain vegetation and eroding the productivity basis of the ecosystem. It is highly important to maintain the natural hydrological pattern of the Mekong River, particularly the dry-season water levels, to preserve Tonle Sap Lake's ecosystem productivity.

  11. Water level response to hydropower development in the upper Mekong River.

    Science.gov (United States)

    Li, Shaojuan; He, Daming

    2008-05-01

    Environmental changes and their transboundary influences on the Mekong watercourse system have been an international research focus in recent years, but the opinions and results related to the impacts of upper Mekong River dams are quite different. In this paper, based on the records of water levels from 1960 to 2003 at three mainstream sites in the upper Mekong River, a quantitative examination has been undertaken into characteristics of the mainstream water-level process at multiple timescales and its response to cascade development. The major results are: i) Annual mean, wet period mean, and the mean water levels during the period between March and April (PBMA period) exhibit a significant increasing trend at Jiuzhou and Yunjinghong sites, which are influenced by large-scale factors such as climate change and solar activity. ii) The interdecadal and interannual variations of annual mean, annual maximum, and wet period mean water levels at three sites show similar features during the dam construction period. iii) The interdecadal variations of PBMA period water level show a gradual increase at Gajiu and Yunjinghong sites but a falling trend at Jiuzhou; these trends confirm that there is some regulation on the flow in the dry season caused by the two existing dams. iv) The downstream effects of the present dams on water levels are very limited at the annual mean and wet season mean levels, not apparent at the monthly and yearly timescales, and relatively significant at daily and hourly timescales.

  12. The spatial distribution of vulnerability to the health impacts of flooding in the Mekong Delta, Vietnam

    Science.gov (United States)

    Phung, Dung; Rutherford, Shannon; Dwirahmadi, Febi; Chu, Cordia; Do, Cuong Manh; Nguyen, Thuy; Duong, Nam Chi

    2016-06-01

    Flooding causes significant public health issues. The Mekong Delta has been considered the region to be the most vulnerable to flooding in Vietnam. This study assessed the spatial vulnerability of the health impacts of flooding in the Mekong Delta region, Vietnam. This study applied a vulnerability assessment framework which was computed as the function of three dimensions: exposure, sensitivity, and adaptive capacity. The indicators for each dimension were derived from the relevant literature, consultations with experts, and data availability. An analytic hierarchy process (AHP) and a principal component analysis (PCA) were used to determine the weight of indicators. Vulnerability indexes (VIs) were then computed for each province. A total of 29 indicators (sensitivity index, 14; adaptive capacity index, 13; and exposure index, 2) were employed to evaluate the vulnerability to the health impacts of flooding at a provincial level. The results of AHP revealed that the highest VIs were found in the Dong Thap and An Giang provinces (VI, 1.948 and 1.574, respectively). VIs were distributed with higher indexes in upstream provinces close to a river than in coastal provinces. PCA generated three components from the 29 indicators, and the VIs computed from the PCA method are in substantial agreement with the AHP method (ICC = 0.71, p Vietnam. Individual plans for health preparedness and adaption to flooding should be developed for each province in the Mekong Delta region.

  13. Ecosystem Resilience to Drought and Temperature Anomalies in the Mekong River Basin

    Science.gov (United States)

    Na-U-Dom, T.; García, M.; Mo, X.

    2017-05-01

    Climate change is leading to an increasing in the frequency and intensity of extreme weather events, which significantly affect ecosystems stability. In this study, ecological stability metrics in response to wet/dry events and warm/cold events on vegetation greenness were assessed using an auto-regressive model of NDVI in the Mekong River basin (around 759,000 km2) where large ecological and climatic gradients exist. Gridded temperature, and the Global Standard Precipitation Evaporation Index (SPEI) and antecedent NDVI were used as model predictors. The forest in north Laos was more resilient to the temperate and wet/dry anomalies events than other regions in the basin. Drought reduced green biomass in north Laos, northeast Thailand and Myanmar, but in these tropical climate regions’ the vegetation biomass was also more responsive by higher temperatures. Vegetation in northeast Thailand, Cambodia and the Mekong delta were less sensitive to the temperature anomalies effect compared to other part of Mekong River basin. The map of resistance and resilience metrics can help to determine the most vulnerable regions to extreme events for policy makers.

  14. Debating land degradation: strategy development for Bolivian mountain valleys

    NARCIS (Netherlands)

    Kessler, A.; Stroosnijder, L.

    2010-01-01

    A debate on response strategies to rural poverty and land degradation has relevance for the core business of this journal. Based on extensive fieldwork in the mountain valleys of Chuquisaca, Bolivia, this paper discusses farming and migration in the region, and elaborates on the required components

  15. Debating land degradation: strategy development for Bolivian mountain valleys

    NARCIS (Netherlands)

    Kessler, A.; Stroosnijder, L.

    2010-01-01

    A debate on response strategies to rural poverty and land degradation has relevance for the core business of this journal. Based on extensive fieldwork in the mountain valleys of Chuquisaca, Bolivia, this paper discusses farming and migration in the region, and elaborates on the required components

  16. Historical impact of water infrastructure on water levels of the Mekong River and the Tonle Sap System

    Directory of Open Access Journals (Sweden)

    T. A. Cochrane

    2014-04-01

    Full Text Available The rapid rate of water infrastructure development in the Mekong basin is a cause for concern due to its potential impact on fisheries and downstream natural ecosystems. In this paper we analyse the historical water levels of the Mekong River and Tonle Sap system by comparing pre and post 1991 daily observations from six stations along the Mekong mainstream from Chiang Sean (northern Laos, to Stung Treng (Cambodia, and the Prek Kdam station on the Tonle Sap River. Observed alterations in water level patterns along the Mekong are linked to temporal and spatial trends in water infrastructure development from 1960 to 2010. We argue that variations in historical climatic factors are important, but they are not the main cause of observed changes in key hydrological indicators related to ecosystem productivity. Our analysis shows that the development of mainstream dams in the upper Mekong basin in the post-1991 period have resulted in a significant increase of 7 day minimum (+91.6%, fall rates (+42%, and the number of water level fluctuations (+75 observed in Chiang Sean. This effect diminishes downstream until it becomes negligible at Mukdahan (northeast Thailand, which represents a drainage area of over 50% of the total Mekong Basin. Further downstream at Pakse (southern Laos, alterations to the number of fluctuations and rise rate became strongly significant after 1991. The observed alterations slowly decrease downstream, but modified rise rates, fall rates, and dry season water levels were still quantifiable and significant as far as Prek Kdam. This paper provides the first set of evidence of hydrological alterations in the Mekong beyond the Chinese dam cascade in the upper Mekong. Given the evident alterations with no precedence at Pakse and downstream, post-1991 changes can also be directly attributed to water infrastructure development in the Chi and Mun basins of Thailand. A reduction of 23 and 11% in the water raising and fall rates

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

    Directory of Open Access Journals (Sweden)

    H. Lauri

    2012-05-01

    Full Text Available The transboundary Mekong River is facing two on-going changes that are estimated 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 the 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 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 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 to 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 increase the

  18. 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

  19. The insecticide resistance status of malaria vectors in the Mekong region

    Directory of Open Access Journals (Sweden)

    Denis Leen

    2008-06-01

    Full Text Available Abstract Background Knowledge on insecticide resistance in target species is a basic requirement to guide insecticide use in malaria control programmes. Malaria transmission in the Mekong region is mainly concentrated in forested areas along the country borders, so that decisions on insecticide use should ideally be made at regional level. Consequently, cross-country monitoring of insecticide resistance is indispensable to acquire comparable baseline data on insecticide resistance. Methods A network for the monitoring of insecticide resistance, MALVECASIA, was set up in the Mekong region in order to assess the insecticide resistance status of the major malaria vectors in Cambodia, Laos, Thailand, and Vietnam. From 2003 till 2005, bioassays were performed on adult mosquitoes using the standard WHO susceptibility test with diagnostic concentrations of permethrin 0.75% and DDT 4%. Additional tests were done with pyrethroid insecticides applied by the different national malaria control programmes. Results Anopheles dirus s.s., the main vector in forested malaria foci, was susceptible to permethrin. However, in central Vietnam, it showed possible resistance to type II pyrethroids. In the Mekong delta, Anopheles epiroticus was highly resistant to all pyrethroid insecticides tested. It was susceptible to DDT, except near Ho Chi Minh City where it showed possible DDT resistance. In Vietnam, pyrethroid susceptible and tolerant Anopheles minimus s.l. populations were found, whereas An. minimus s.l. from Cambodia, Laos and Thailand were susceptible. Only two An. minimus s.l. populations showed DDT tolerance. Anopheles vagus was found resistant to DDT and to several pyrethroids in Vietnam and Cambodia. Conclusion This is the first large scale, cross-country survey of insecticide resistance in Anopheles species in the Mekong Region. A unique baseline data on insecticide resistance for the Mekong region is now available, which enables the follow-up of trends

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

    Science.gov (United States)

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

    2012-12-01

    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 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 increase the uncertainty of the

  1. Organic farming at the farm level

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.; Madsen, Niels; Ørum, Jens Erik

    The purpose of this report is to present possible impacts of new technology and changes in legislation on the profitability of different types of organic farms. The aim is also to look at both the current and future trends in the organic area in Denmark. The farm level analyses are carried out...... as part of a larger project entitled “Economic analyses of the future development of organic farming – effects at the field, farm, sector and macroeconomic level”. The project links effects at the field-level with analyses at the farm level. These effects are then used in sector and macroeconomic analyses...

  2. Organic Farming in Austria

    OpenAIRE

    Vogl, C.R.; Heß, J

    1999-01-01

    During the present decade, Austria has experienced a dramatic increase in organic farming among those countries that comprise the European Union (EU). For example, in 1992, approximately 2,000 farms were practicing organic, ecological, or biodynamic farming methodes. By 1997 the number of certified organic farms plus those in transition from conventional farming had increased 10-fold to some 20,000 farms. This represents almost 9% of the total farms in Austria and an area of 345,375 ha, or 10...

  3. Measuring Bedload Sediment Flux in Large Rivers: New Data from the Mekong River and Its Applications in Assessing Geomorphic Change

    Science.gov (United States)

    Best, J.; Hackney, C. R.; Parsons, D. R.; Darby, S. E.; Leyland, J.; Aalto, R. E.; Nicholas, A. P.

    2014-12-01

    Many large rivers are undergoing renewed and increasing anthropogenic-induced change as water diversions, new dams and greater water demands place enhanced stresses on these river basins. Examples of rivers undergoing significant change include the Amazon, Madeira, Nile, Yangtze and Mekong, with considerable ongoing debate raging as to the long-term geomorphic and ecological effects of major anthropogenic interventions. Assessing the effects of such change in large rivers is demanding, one reason being that sediment transport is often exceedingly difficult to measure, and thus data needed to inform the debate on the impact of anthropogenic change is frequently lacking. Here, we report on one aspect of research being undertaken as part of STELAR-S2S - Sediment Transfer and Erosion on Large Alluvial Rivers - that is seeking to better understand the relationship between climate, anthropogenic impacts and sediment transport in some of the world's largest rivers. We are using the Lower Mekong River as our study site, with the Mekong delta being one of only three in the world classified by the IPCC as 'extremely vulnerable' to future changes in climate. Herein, we describe details of bedload sediment flux estimation using repeated high-resolution multibeam echo sounder (MBES) bathymetric mapping along the Lower Mekong and Tonle Sap rivers in Cambodia. We are using MBES to quantify the spatial variation in sediment transport both along and also across the river at 11 sites in the study area. Predicted increases in the extraction of sediment from the river through sand dredging are thought likely to cause a significant decrease in downstream sediment flux, and future dam construction along the Mekong main channel potentially offers another source of significant change. These field results will be set in the light of these anthropogenic drivers on sediment flux in the Mekong River and their possible future effects on bar formation and channel migration.

  4. Sutter Buttes-the lone volcano in California's Great Valley

    Science.gov (United States)

    Hausback, Brain P.; Muffler, L.J. Patrick; Clynne, Michael A.

    2011-01-01

    The volcanic spires of the Sutter Buttes tower 2,000 feet above the farms and fields of California's Great Valley, just 50 miles north-northwest of Sacramento and 11 miles northwest of Yuba City. The only volcano within the valley, the Buttes consist of a central core of volcanic domes surrounded by a large apron of fragmental volcanic debris. Eruptions at the Sutter Buttes occurred in early Pleistocene time, 1.6 to 1.4 million years ago. The Sutter Buttes are not part of the Cascade Range of volcanoes to the north, but instead are related to the volcanoes in the Coast Ranges to the west in the vicinity of Clear Lake, Napa Valley, and Sonoma Valley.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  6. Semi-empirical mixed statistical flood forecasting for the Mekong River

    Science.gov (United States)

    Khurram Shahzad, Muhammad; Ihringer, Jürgen; Plate, Erich J.

    2010-05-01

    An ongoing study for improving flood forecasting for the Mekong River by data based modeling by mix of statistical methods and semi-empirical approach has yielded intermediate results, which reduced forecasting errors of previous forecasting models. In contrast to deterministic or semi-deterministic approach, the procedure is adopted to build the physical reality based semi-empirical model from the available data set. The forecast in data scarce basin like Mekong always remained a challenge for hydrologists where with the River of total length of 4000 km and 795000 Sq.km area of catchment has only 32 rainfall gauging stations and 8 runoff gauges in its key contributing catchments with consistent data. Therefore, simple rainfall runoff modeling module is developed for the estimation of inflows contributed by lateral catchments along the River Mekong and added into pre-developed runoff routing algorithm. The simple 3 parameter Nash-cascade model is applied in non-linear mode with varying runoff coefficients (RC). These runoff coefficients were pre-computed by multiple linear auto-regressions algorithms. It has been found that runoff coefficients increase along the flood season from its onset in May to end in October. However this increase was found highly dependent on previous month's RC values. This RC dependency on previous months is exploited to develop multiple linear regressions for estimation of forthcoming month RC's. These pre-computed monthly RC's were used in Nash-cascade to estimate runoff temporal distribution from daily areal average incremental rainfall for each sub-catchment. The algorithm was developed to give flood forecast at 4 points in middle Mekong River starting from N.Phanom in Lao-PDR to Stung Treng in Cambodia. There are a total of 4 sub-catchments which contribute runoff into the main Mekong River from its travel along these points. Separate rainfall-runoff Nash-cascade models were developed and added into routing algorithm to compute 1 to 5

  7. Combination of multi-mission altimetry data along the Mekong River with spatio-temporal kriging

    Science.gov (United States)

    Boergens, Eva; Buhl, Sven; Dettmering, Denise; Klüppelberg, Claudia; Seitz, Florian

    2016-12-01

    River water-level time series at fixed geographical locations, so-called virtual stations, have been computed from single altimeter crossings for many years. Their temporal resolution is limited by the repeat cycle of the individual altimetry missions. The combination of all altimetry measurements along a river enables computing a water-level time series with improved temporal and spatial resolutions. This study uses the geostatistical method of spatio-temporal ordinary kriging to link multi-mission altimetry data along the Mekong River. The required covariance models reflecting the water flow are estimated based on empirical covariance values between altimetry observations at various locations. In this study, two covariance models are developed and tested in the case of the Mekong River: a stationary and a non-stationary covariance model. The proposed approach predicts water-level time series at different locations along the Mekong River with a temporal resolution of 5 days. Validation is performed against in situ data from four gauging stations, yielding RMS differences between 0.82 and 1.29 m and squared correlation coefficients between 0.89 and 0.94. Both models produce comparable results when used for combining data from Envisat, Jason-1, and SARAL for the time period between 2002 and 2015. The quality of the predicted time series turns out to be robust against a possibly decreasing availability of altimetry mission data. This demonstrates that our method is able to close the data gap between the end of the Envisat and the launch of the SARAL mission with interpolated time series.

  8. Combination of multi-mission altimetry data along the Mekong River with spatio-temporal kriging

    Science.gov (United States)

    Boergens, Eva; Buhl, Sven; Dettmering, Denise; Klüppelberg, Claudia; Seitz, Florian

    2017-05-01

    River water-level time series at fixed geographical locations, so-called virtual stations, have been computed from single altimeter crossings for many years. Their temporal resolution is limited by the repeat cycle of the individual altimetry missions. The combination of all altimetry measurements along a river enables computing a water-level time series with improved temporal and spatial resolutions. This study uses the geostatistical method of spatio-temporal ordinary kriging to link multi-mission altimetry data along the Mekong River. The required covariance models reflecting the water flow are estimated based on empirical covariance values between altimetry observations at various locations. In this study, two covariance models are developed and tested in the case of the Mekong River: a stationary and a non-stationary covariance model. The proposed approach predicts water-level time series at different locations along the Mekong River with a temporal resolution of 5 days. Validation is performed against in situ data from four gauging stations, yielding RMS differences between 0.82 and 1.29 m and squared correlation coefficients between 0.89 and 0.94. Both models produce comparable results when used for combining data from Envisat, Jason-1, and SARAL for the time period between 2002 and 2015. The quality of the predicted time series turns out to be robust against a possibly decreasing availability of altimetry mission data. This demonstrates that our method is able to close the data gap between the end of the Envisat and the launch of the SARAL mission with interpolated time series.

  9. 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.

  10. Monitoring groundwater storage change in Mekong Delta using Gravity Recovery and Climate Experiment (GRACE) data

    Science.gov (United States)

    Aierken, A.; Lee, H.; Hossain, F.; Bui, D. D.; Nguyen, L. D.

    2016-12-01

    The Mekong Delta, home to almost 20 million inhabitants, is considered one of the most important region for Vietnam as it is the agricultural and industrial production base of the nation. However, in recent decades, the region is seriously threatened by variety of environmental hazards, such as floods, saline water intrusion, arsenic contamination, and land subsidence, which raise its vulnerability to sea level rise due to global climate change. All these hazards are related to groundwater depletion, which is the result of dramatically increased over-exploitation. Therefore, monitoring groundwater is critical to sustainable development and most importantly, to people's life in the region. In most countries, groundwater is monitored using well observations. However, because of its spatial and temporal gaps and cost, it is typically difficult to obtain large scale, continuous observations. Since 2002, the Gravity Recovery and Climate Experiment (GRACE) satellite gravimetry mission has delivered freely available Earth's gravity variation data, which can be used to obtain terrestrial water storage (TWS) changes. In this study, the TWS anomalies over the Mekong Delta, which are the integrated sum of anomalies of soil moisture storage (SMS), surface water storage (SWS), canopy water storage (CWS), groundwater storage (GWS), have been obtained using GRACE CSR RL05 data. The leakage error occurred due to GRACE signal processing has been corrected using several different approaches. The groundwater storage anomalies were then derived from TWS anomalies by removing SMS, and CWS anomalies simulated by the four land surface models (NOAH, CLM, VIC and MOSAIC) in the Global Land Data Assimilation System (GLDAS), as well as SWS anomalies estimated using ENVISAT satellite altimetry and MODIS imagery. Then, the optimal GRACE signal restoration method for the Mekong Delta is determined with available in-situ well data. The estimated GWS anomalies revealed continuously decreasing

  11. Managing Mekong Mud and its Impact on Fish, Hydropower and People

    Science.gov (United States)

    Wild, T. B.; Loucks, D. P.

    2013-12-01

    The Lancang/Mekong River flows from the Tibetan Plateau through the Upper Mekong Basin in China (where it is called the Lancang Jiang) to the Lower Mekong Basin (LMB) in Myanmar, Laos, Thailand, Cambodia, and Vietnam, before discharging into the South China Sea. The river has remained largely unaltered for much of its history, but today hydropower reservoirs are being designed and developed at a rapid pace. Some 60 million people living in the basin have depended on the basin's ecosystems to produce much of their food and income. The health and productivity of the ecosystems are dependent upon the river's natural flow and sediment regimes, both of which could be significantly altered by the rapid construction of dams. This presentation focuses on the potential impacts of dam development and alternative sediment management options, where feasible, including flushing, sluicing, bypassing, and density current venting. We evaluate whether these techniques can improve reservoir sediment outflows without damaging the environmental system we are attempting to preserve. We also evaluate the accompanying losses in hydropower production necessary to achieve the improved sediment passage. This study focuses on dams in China, Cambodia, Laos and Vietnam, both on the mainstream Mekong River and on its tributaries. A sediment simulation model was developed specifically to conduct these evaluations. This model implements a daily time-step mass-balance simulation of flow and sediment to predict the spatial and temporal accumulation, depletion, and distribution of sediment in river reaches and in reservoirs under different flow and sediment management policies. Results of simulations suggest that more benign (with regard to sediment) alternatives to the currently proposed locations and designs of dams exist and should be considered. While sediment management alternatives have the potential to increase sediment loads discharged downstream, careful attention must be paid to the

  12. 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

  13. 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...

  14. IMPACT OF ECONOMIC GLOBALIZATION ON THE HUMAN TRAFFICKING IN THE GREATER MEKONG SUB-REGION COUNTRIES

    OpenAIRE

    Peerapeng, Suk-Rutai; Chaitip, Prasert; Chaiboonsri, Chukiat; Kovacs, Sandor; Balogh, Peter

    2012-01-01

    This study examines the impact of economic globalization on the human trafficking inflows into the Greater Mekong Sub-region (GMS) countries. The paper empirically tests for a cross-section of six countries, including Cambodia, the Yunnan Province of the People’s Republic of China (PRC), Lao People’s Democratic Republic (Lao PRD), Myanmar, Thailand, and Vietnam. Employing the Pooled OLS estimator, as the theory predicts, the economic globalization increases trafficking inflow into the GMS...

  15. Haemoragisk Rift Valley Fever

    DEFF Research Database (Denmark)

    Fabiansen, Christian; Thybo, Søren

    2007-01-01

    A case of fatal hemorrhagic Rift Valley fever during an epidemic in Kenya's North Eastern Province in January 2007 is described.......A case of fatal hemorrhagic Rift Valley fever during an epidemic in Kenya's North Eastern Province in January 2007 is described....

  16. Rift Valley Fever Virus

    Science.gov (United States)

    Rift Valley fever virus (RVFV) is a mosquito-transmitted virus or arbovirus that is endemic in sub-Saharan Africa. In the last decade, Rift Valley fever (RVF) outbreaks have resulted in loss of human and animal life, as well as had significant economic impact. The disease in livestock is primarily a...

  17. Silicon Valley Ecosystem

    Institute of Scientific and Technical Information of China (English)

    Joseph Leu

    2005-01-01

    @@ It is unlikely that any industrial region of the world has received as much scrutiny and study as Silicon Valley. Despite the recent crash of Internet and telecommunications stocks,Silicon Valley remains the world's engine of growth for numerous high-technology sectors.

  18. 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

  19. 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

  20. Book Review: Shrestha, Omkar Lal, and Aekapol Chongvilaivan (eds, Greater Mekong Subregion: From Geographical to Socio-economic Integration

    Directory of Open Access Journals (Sweden)

    Timotheus J. Krahl

    2014-01-01

    Full Text Available Book Review of the edited volume: Omkar Lal Shrestha and Aekapol Chongvilaivan (eds (2013, Greater Mekong Subregion: From Geographical to Socio-economic Integration. Singapore: Institute of Southeast Asian Studies (ISEAS, ISBN: 978-981-4379-68-7, 270 pages

  1. Rice market integration in the Mekong river delta : the successful liberalisation of the domestic food market in Vietnam

    NARCIS (Netherlands)

    Hai, Luu Thanh Duc; Lutz, Clemens; Praagman, Cornelis

    2004-01-01

    This article analyses the spatial price differences in the rice market of the Mekong River Delta to assess the impact of the liberalisation policies on its functioning. The results of these policies carried out during the last two decades are impressive. The rice market system in the Delta is

  2. 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 o

  3. Vietnamese Women in Academic Leadership: Experiences of Mid-Level Women Leaders in Universities and Colleges in the Mekong Delta

    Science.gov (United States)

    Dang, Ngoc Lan Thi

    2012-01-01

    Academic women in the Mekong Delta (MD) in southern Viet Nam remain underrepresented in key leadership positions and other positions of power and influence in their institutions. This situation exists regardless of various local, national, and international policies on gender equality and the implementation of numerous action plans, strategies,…

  4. 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 due to better land tenure securi

  5. 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

  6. Organic farming at the farm level

    DEFF Research Database (Denmark)

    Jacobsen, Brian H.; Madsen, Niels; Ørum, Jens Erik

    The purpose of this report is to present possible impacts of new technology and changes in legislation on the profitability of different types of organic farms. The aim is also to look at both the current and future trends in the organic area in Denmark. The farm level analyses are carried out...... as part of a larger project entitled “Economic analyses of the future development of organic farming – effects at the field, farm, sector and macroeconomic level”. The project links effects at the field-level with analyses at the farm level. These effects are then used in sector and macroeconomic analyses......, which are described in other reports from Food and Resource Economic Institute (Jacobsen, 2005 and Andersen et al., 2005). This gives coherent results from the field to the macroeconomic level regarding changes in technology and legislation....

  7. Dams on Mekong tributaries as significant contributors of hydrological alterations to the Tonle Sap Floodplain in Cambodia

    Directory of Open Access Journals (Sweden)

    M. E. Arias

    2014-02-01

    Full Text Available River tributaries have a key role in the biophysical functioning of the Mekong Basin. Of particular attention 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 would alter the hydrology of the Tonle Sap 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 definite future development scenario (DF 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 d−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 actually be exploited and that dams would be built even in locations where there is a high risk of ecological disruptions. Hence, retrofitting current designs and operations to promote sustainable hydropower practices that optimize multiple river services – rather than just maximize hydropower generation

  8. 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

  9. 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

    2015-10-01

    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.

  10. Perceptions of water, sanitation and health: a case study from the Mekong Delta, Vietnam.

    Science.gov (United States)

    Herbst, S; Benedikter, S; Koester, U; Phan, N; Berger, C; Rechenburg, A; Kistemann, T

    2009-01-01

    In the Mekong Delta in the south of Vietnam about 5.7 million people lack access to safe drinking water and 10 million people in rural areas live without adequate sanitation. Between May and August, 2007 a survey was carried out in An Bin, a peri-urban ward in the Mekong Delta, to gain insight into water, sanitation and health as well as to health-related hygiene behaviour. The study employed a combination of quantitative (standardized questionnaire) and qualitative (focus group discussions, semi-structured interviews) methods. The most important features in the choice of drinking water sources are matters of hygiene and the taste of the water. The majority (74%) of the 120 households surveyed indicated their ownership of a sanitation facility, but the fish pond toilet (64%) which is predominantly utilized is considered to be unimproved sanitation. The local peri-urban population link water and hygiene to health, but sanitation instead to environmental pollution. This and other outcomes lead to the assumption that people have a basic knowledge of proper hygiene behaviour. However, hygiene measures such as hand washing are put into practice in an untimely manner, most likely due to a misconception of risks and/or a lack of background knowledge of cause-effect relationships as well as ingrained habits.

  11. Snow Cover and Precipitation Impacts on Dry Season Streamflow in the Lower Mekong Basin

    Science.gov (United States)

    Cook, Benjamin I.; Bell, A. R.; Anchukaitis, K. J.; Buckley, B. M.

    2012-01-01

    Climate change impacts on dry season streamflow in the Mekong River are relatively understudied, despite the fact that water availability during this time is critically important for agricultural and ecological systems. Analyses of two gauging stations (Vientiane and Kratie) in the Lower Mekong Basin (LMB) show significant positive correlations between dry season (March through May, MAM) discharge and upper basin snow cover and local precipitation. Using snow cover, precipitation, and upstream discharge as predictors, we develop skillful regression models for MAM streamflow at Vientiane and Kratie, and force these models with output from a suite of general circulation model (GCM) experiments for the twentieth and twenty-first centuries. The GCM simulations predict divergent trends in snow cover (decreasing) and precipitation (increasing) over the twenty-first century, driving overall negligible long-term trends in dry season streamflow. Our study demonstrates how future changes in dry season streamflow in the LMB will depend on changes in snow cover and precipitation, factors that will need to be considered when assessing the full basin response to other climatic and non-climatic drivers.

  12. Estimating the Burden of Japanese Encephalitis Virus and Other Encephalitides in Countries of the Mekong Region

    Science.gov (United States)

    Tarantola, Arnaud; Goutard, Flavie; Newton, Paul; de Lamballerie, Xavier; Lortholary, Olivier; Cappelle, Julien; Buchy, Philippe

    2014-01-01

    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. PMID:24498443

  13. Population dynamics of shrimps in littoral marine waters of the Mekong Delta, south of Viet Nam.

    Science.gov (United States)

    Dinh, T D; Moreau, J; Van, M V; Phuong, N T; Toan, V T

    2010-07-15

    The population dynamics of eight commercial species of shrimp (Haliporoides sibogae, Harpiosquilla harpax, Metapenaeus affinis, Metapenaeus brevicornis, Metapenaeus tenuipes, Parapenaeopsis cultrirostris, Parapenaeopsis gracillima and Parapenaeus maxilipedo) distributed in littoral marine zone of the Mekong Delta were investigated. Length-based stock assessment using FiSAT II software package was used to assess the growth and mortality parameters: Asymptotic size (L8), growth coefficient (K), total (Z) and natural (M) mortality, exploitation rate (E), recruitment pattern, current probability of capture and selectivity of fishing gears. Yield-per-recruit analyses were carried out showing different levels of the exploitation. Results showed that the maximum sustainable yield would be reached for an exploitation rate higher than the current one for each population. However, the size of first capture should be increased for every population. The findings indicated that the current exploitations of shrimp populations distributed in littoral marine zone of the Mekong Delta are under exploitation level for maximum sustainable yield; however, all the shrimp populations are subject to growth over-exploitation.

  14. Late Holocene depositional environments and coastal evolution of the Mekong River Delta, Southern Vietnam

    Science.gov (United States)

    Lap Nguyen, Van; Ta, Thi Kim Oanh; Tateishi, Masaaki

    2000-08-01

    The Mekong River Delta in Southern Vietnam is a tide-dominated delta and has been formed by the Mekong River system. The sediments are dominantly fine grained and were deposited in the receiving basin with slight inclination of pre-existing deposits in the South China Sea and Gulf of Thailand. Around 6000 to 5000 yr BP maximum Holocene transgression occurred and seawaves surrounded uplands of the Late Pleistocene terrace, basement rock and weathered land in the northern parts of the delta. Double notches were undercut by seawaves on the limestone hill in Hatien at about 4.5 and 2.5 m above present sea level. Marine deposits prevailed throughout the delta. During the highstand and regressions of relative sea level over the last 4550 yr BP, delta progradation has produced a great flat-plain of 62,520 km 2. This extremely fast progradation could be due to: (a) very high sediment supply depositing in the slight inclination of the receiving basin; (b) neotectonic movements and relative sea-level changes; (c) widespread mangrove forests playing an important role to enhance sediment accumulation. Former mangrove marshy deposits were significantly developed in the Plain of Reeds and Longxuyen Quadrangle. Mangrove marshes have also been developing well in the Camau Peninsula and present coastlines. Moreover, regressions over the last 4550 yr BP have produced many distinct sets of relict beach ridges which are useful in distinguishing the former coastlines and evolutionary history of the delta.

  15. 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.

  16. Values in Organic Farming

    DEFF Research Database (Denmark)

    Kjærgård, Bente; Pedersen, Kirsten Bransholm; Land, Birgit

    The study focuses on the recent debate about what is, or what constitutes, organic farming and what is the right path for organic farming in the future. The study is based on a critical discourse analysis of the controversy about suspending the private standard for organic farming adopted...

  17. Values in Organic Farming

    DEFF Research Database (Denmark)

    Kjærgård, Bente; Pedersen, Kirsten Bransholm; Land, Birgit

    The study focuses on the recent debate about what is, or what constitutes, organic farming and what is the right path for organic farming in the future. The study is based on a critical discourse analysis of the controversy about suspending the private standard for organic farming adopted...

  18. 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.

  19. Alley Farming in Thailand

    Directory of Open Access Journals (Sweden)

    Teerapol Silakul

    2010-08-01

    Full Text Available Poverty alleviation and environmental preservation are very important issues to many governments. Alley farming is beneficial to the environment because it conserves soil and sustains yields over time. Specifically, alley farming reduces soil erosion, which is a major problem in Thailand. Alley farming was conducted on a farmer’s field at Khaokwan Thong, a village in Uthaithani Province, Northern Thailand. We did a two-by-two factorial with and without alley farming, and with and without fertilizer. From this study, we observed that the two species used, Leucaena leucocephala and Acacia auriculiformis, grow well in Thailand, and that alley farming is suitable for Thailand. Few Thai farmers have heard about alley farming. However, it is nevertheless useful to know that there is potential for alley farming in Thailand using the two species. These plants, based upon the diameter and height measurements provided, grew well.

  20. Status of Fruit Farming in Central Valley of Khyber Pakhtunkhwa

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    Nisar Ali Shah,

    2014-10-01

    Full Text Available This retrospective study was conducted in four districts of Khyber Pakhtunkhwa namely Charsadda, Nowshera, Mardan and Peshawar during January February, 2013 to examine the status and factors affecting fruit orchards. A total of Sixty four fruit orchards growers were interviewed on the basis of land acquisition. Data indicates that farmer areas for citrus and planted Stone fruit such as peach, plum and apricot were declined in the last 10 years while the area under pear and loquat were increased. The study results also indicate that a number of factors were affecting fruit orchards. These problems were ranked as (1 diseases/insects, followed by (2 high price, (3 water shortage problem, (4 adulteration in inputs, (5 marketing problem and (6 non-availability of credit. It is concluded that various factors are responsible for the decline in production of fruit orchards. It is thus, recommended that agriculture department should regularly disseminate technical-know-how regarding improved fruit orchards management practices through training, field days and workshop and other awareness programmes for fruit orchards growers. The government should also keep check and balance on price and quality of inputs to encourage fruit orchard growers to increase their production.

  1. The ecological complexity of the Thai-Laos Mekong River: III. Health status of Mekong catfish and cyprinids, evidence of bioaccumulative effects.

    Science.gov (United States)

    Phanwichien, Kantimanee; Pradermwong, Apichart; Keenan, Helen E; Masawang, Kamonporn; Lauhachinda, Nitaya; Songsasen, Apisit; Sakultantimetha, Arthit; Bangkedphol, Sornnarin; Gaines, Alec F

    2010-11-01

    Histopathology of fish organs was used as biomarkers of toxicity from environmental pollutants. A total of 117 fishes comprising of 52 cyprinids and 65 catfishes were randomly collected from the Mekong River from 5 stations: Chiang Rai, Loei, Nongkhai, Nakhon Phanom and Ubonratchathani. The health of the fish collected in December and April, winter and summer respectively, was evaluated. All fish from the 5 stations developed pathologic lesions with the same characteristics in their livers, kidneys and spleen. In the liver, there was vacuolation of hepatocytes, accumulation of brownish-green granules in the cytoplasm of hepatocytes, necrosis of hepatocytes, granuloma formation and angiogenesis. Kidney lesions consisted of glomerular degeneration, necrosis and focal hyperplasia of renal tubules. In the spleen, there were haemorrhage, melanomacrophage centre infiltration and necrosis of the red pulp and white pulp. The pathologic severity of the catfish was found to be more severe than in the cyprinids and the catfish collected in summer were less healthy than the catfish collected in the winter. These histopathological appearances might arise from the fish feeding on the benthos and thereby accumulating toxic pollutants in their organs. The activities of the serum enzymes, Glutamic Oxalacetic Transaminase (GOT) and Glutamic Pyruvic Transaminase (GPT), were markedly increased, indicating detoxification activity. The highest activity of GOT found in the cyprinids from Chiang Rai 365.30 U/L whereas in the catfish from Nakhon Phanom the activity was 300.73 U/L. The highest GPT activity found in the cyprinids from Nakhon Phanom was 203.23 U/L where as in the catfish from the same station was GPT 389.77 U/L. According to the results from this study, catfish collected from Chiang Rai, Nakhon Phanom and Ubonratchathani showed more severe pathological changes than catfish from the other stations. Fish organs and river water were analysed for Polyaromatic Hydrocarbons (PAHs

  2. Geometry of Valley Growth

    CERN Document Server

    Petroff, Alexander P; Abrams, Daniel M; Lobkovsky, Alexander E; Kudrolli, Arshad; Rothman, Daniel H

    2011-01-01

    Although amphitheater-shaped valley heads can be cut by groundwater flows emerging from springs, recent geological evidence suggests that other processes may also produce similar features, thus confounding the interpretations of such valley heads on Earth and Mars. To better understand the origin of this topographic form we combine field observations, laboratory experiments, analysis of a high-resolution topographic map, and mathematical theory to quantitatively characterize a class of physical phenomena that produce amphitheater-shaped heads. The resulting geometric growth equation accurately predicts the shape of decimeter-wide channels in laboratory experiments, 100-meter wide valleys in Florida and Idaho, and kilometer wide valleys on Mars. We find that whenever the processes shaping a landscape favor the growth of sharply protruding features, channels develop amphitheater-shaped heads with an aspect ratio of pi.

  3. Purge at West Valley

    Science.gov (United States)

    Mack, Warren

    1977-01-01

    Tells how the adviser of the student newspaper at West Valley College (Saratoga, California) was dismissed after the newspaper published stories based on investigations into alleged wrongdoings by administration members. (GW)

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

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    Kathryn E Holt

    Full Text Available BACKGROUND: 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. PRINCIPAL FINDINGS: 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. SIGNIFICANCE: 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Berg, Michael [Swiss Federal Institute of Aquatic Science and Technology (Eawag), CH-8600 Dubendorf (Switzerland)]. E-mail: michael.berg@eawag.ch; Stengel, Caroline [Swiss Federal Institute of Aquatic Science and Technology (Eawag), CH-8600 Dubendorf (Switzerland); Trang, Pham Thi Kim [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Hanoi (Viet Nam); Hung Viet, Pham [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, Hanoi (Viet Nam); Sampson, Mickey L. [Resource Development International-Cambodia (RDIC), P.O. Box 494, Phnom Penh (Cambodia); Leng, Moniphea [Resource Development International-Cambodia (RDIC), P.O. Box 494, Phnom Penh (Cambodia); Samreth, Sopheap [Resource Development International-Cambodia (RDIC), P.O. Box 494, Phnom Penh (Cambodia); Fredericks, David [Phnom Penh (Cambodia)

    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 {mu}g/L in Cambodia (average 217 {mu}g/L) and 1-845 {mu}g/L in southern Vietnam (average 39 {mu}g/L), respectively. It also evaluates the situation in Red River delta where groundwater arsenic concentrations vary from 1-3050 {mu}g/L (average 159 {mu}g/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 {mu}g/g (average 7 {mu}g/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 {mu}g/L have a significantly higher arsenic content than control groups (< 50 {mu}g/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.

  6. Floods in Mekong Delta Under Sea-Level Rise Projections By IPCC AR5

    Science.gov (United States)

    Takagi, H.

    2014-12-01

    One of the mightiest rivers in the planet, the Mekong ranks 10th amongst the world's great rivers on the basis of mean annual flow at the mouth. It flows southwards over a distance of approximately 4,800 km from its source to the sea, through six different countries: China, Myanmar, Lao PDR, Thailand, Cambodia and Vietnam. This great basin has been considered to be one of the most sensitive areas in the world to climate change. The present paper investigates fluvial flood hazards in urban areas in the Mekong Delta to inundation due to seasonal flooding, a phenomenon which is likely to be exacerbated by future sea-level rise. Unlike past researches which mainly focus on flooding due to river discharge from upstream or heavy precipitation, the present paper scrutinizes the influence of ocean tides. The research reveals that ocean tides predominantly determine water elevation even in an upstream location such as Can Tho City, 80 km inland from the river mouth, and that the river flow causes tidal damping and effectively reduces the energy of the incoming tides. This tidal damping is especially pronounced during the rainy season. Analysis based on the water levels monitored by the Mekong River Commission reveals that the ground near the riverbank of Can Tho had experienced inundation for a total of 215 hours between July 2009 and June 2010 (2.5% of the time over a one year period). It is also shown that inundation reached up to a maximum height of 47 cm above the roads of Can Tho downtown in this one-year period. Assuming two scenarios of sea-level rise of 25 cm in the middle of the 21st century and 60 cm in the end of the century, all based on the Fifth Assessment Report of Intergovernmental Panel on Climate Change (IPCC AR5) projections, it was found that the duration of inundation will be prolonged from the present percentage of 2.5% to 7.5% and 24% of the year, respectively. It is important to note that while at present this flooding is seasonal and limited, in the

  7. Offshore Wind Farms

    DEFF Research Database (Denmark)

    Lundtang Petersen, Erik; Hasager, Charlotte Bay; Courtney, Michael

    2015-01-01

    The technology behind constructing wind farms offshore began to develop in 1991 when the Vindeby wind farm was installed off the Danish coast (11 Bonus 450 kW turbines). Resource assessment, grid connection, and wind farm operation are significant challenges for offshore wind power just...... as it is for the more traditional onshore wind power, which has been under development since the 1970s. However, offshore projects face extra technical challenges some of which requires in-depth scientific investigations. This article deals with some of the most outstanding challenges concerning the turbine structure...... concern are the problems associated with locating the turbines close together in a wind farm and the problems of placing several large wind farms in a confined area. The environmental impacts of offshore wind farms are also treated, but not the supply chain, that is, the harbors, the installation vessels...

  8. Ethnic and gender differences in farm tasks and safety practices among rural California farm youth.

    Science.gov (United States)

    McCurdy, Stephen A; Kwan, Jonathan A

    2012-01-01

    Agricultural work is hazardous and is common among rural youth, especially those living on farms or ranches. Previous work has shown differences in farm work and injury patterns between boys and girls, but little data exist addressing ethnic differences. This study examined ethnic and gender differences in farm tasks, safety attitudes, and use of protective measures among rural California youth working on farms or ranches. The University of California, Davis Youth Agricultural Injury Study is a longitudinal study focusing on agricultural work experience among youth enrolled in an agricultural sciences curriculum in 10 public high schools in California's Central Valley during the 2001-2005 school years. Using cross-sectional data from the initial entrance survey, we studied 946 participants who reported farm work in the previous year. Median annual hours of farm work varied significantly between boys and girls (p hr; Hispanic girls: 189 hr; White/Other boys: 832 hr; White/Other girls: 468 hr). Girls and Hispanic students were less likely than boys and White/Other students, respectively, to perform hazardous tasks involving tractors, machinery, and chemicals. Median age for initiating work on selected hazardous tasks was up to 3 years later for Hispanic students. Use of task-appropriate safety measures was low in all groups for most hazardous tasks. Boys were more likely than girls to use task-appropriate safety measures, with the exception of seatbelt use when in a car or truck. Hispanic students were more likely than White/Other students to employ safety measures. Girls and Hispanic youth worked fewer farm hours and had reduced exposure to selected hazardous tasks. Use of task-appropriate safety measures was low for all groups but increased for Hispanic students. Further study should explore reasons for low use of safety measures and develop educational efforts to bring about social norm changes promoting their use.

  9. 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.

  10. Developing Detailed Foresight Narratives: a Participatory Technique from the Mekong Region

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    Tira Foran

    2013-12-01

    Full Text Available Narratives that explore uncertain events are central to a variety of future-oriented approaches ranging from planning to community visioning. Techniques to create interesting narratives, however, have been overlooked in the peer-reviewed environmental foresight literature. We describe a participatory, multidimensional, pragmatic technique to generate qualitative foresight ("scenario" narratives. We applied this technique in the Mekong region of Southeast Asia during 11 workshops conducted in 5 countries and 1 regional setting. To improve consideration of systemic connections, narratives were shared between the six settings, allowing participants to understanding cross-scale enablers and inhibitors of desired development outcomes. A second innovative feature is elaboration of character-oriented narratives. We discuss how the technique responds to ongoing methodological challenges of critical inquiry, policy salience, and agency.

  11. Hydraulic Bureaucracy in a Modern Hydraulic Society – Strategic Group Formation in the Mekong Delta, Vietnam

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    Hans-Dieter Evers

    2009-10-01

    Among these strategic groups, the hydraulic bureaucracy and hydraulic construction business are the most crucial in terms of the specific role they play in the hydraulic landscape of the Mekong delta. Both groups exert considerable influence on water resources management and strive for the same resources, namely public funds (including Overseas Development Aid that is directed to hydraulic infrastructure development. This paper illustrates how both groups have emerged due to the growing need for water resources management in the delta and how they have set up alliances for mutually sharing resources in the long run. Furthermore, it is shown how both groups have adapted their resource-oriented strategies and actions to respond to the changes in the economic and political environment in Vietnam’s recent history.

  12. Modeling the Hydropower–Food Nexus in Large River Basins: A Mekong Case Study

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    Jamie Pittock

    2016-09-01

    Full Text Available An increasing global population and growing wealth are raising demand for energy and food, impacting on the environment and people living in river basins. Sectoral decision-making may not optimize socio-economic benefits because of perverse impacts in other sectors for people and ecosystems. The hydropower–food supply nexus in the Mekong River basins is assessed here in an influence model. This shows how altering one variable has consequent effects throughout the basin system. Options for strategic interventions to maximize benefits while minimizing negative impacts are identified that would enable national and sub-national policy makers to take more informed decisions across the hydropower, water and food supply sectors. This approach should be further tested to see if it may aid policy making in other large river systems around the world.

  13. Node and Regime: Interdisciplinary Analysis of Water-Energy-Food Nexus in the Mekong Region

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    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.

  14. Forest Aboveground Biomass Estimation in the Greater Mekong, Subregion and Russian Siberia

    Science.gov (United States)

    Pang, Yong; Li, Zengyuan; Sun, Gouqing; Zhang, Zhiyu; Schmullius, Christiane; Meng, Shili; Ma, Zhenyu; Lu, Hao; Li, Shiming; Liu, Qingwang; Bai, Lina; Tian, Xin

    2016-08-01

    Forests play a vital role in sustainable development and provide a range of economic, social and environmental benefits, including essential ecosystem services such as climate change mitigation and adaptation. We summarized works in forest aboveground biomass estimation in Greater Mekong Subregion (GMS) and Russian Siberia (RuS). Both regions are rich in forest resources. These mapping and estimation works were based on multiple-source remote sensing data and some field measurements. Biomass maps were generated at 500 m and 30 m pixel size for RuS and GMS respectively. With the available of the 2015 PALSAR-2 mosaic at 25 m spacing, Sentinel-2 data at 20 m, we will work on the biomass mapping and dynamic study at higher spatial resolution.

  15. Boosting Farm Produce Supply

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In the wake of escalating inflation,securing farm produce supply and stablizing grain prices could help to alleviate economic pressure The Chinese Government has pledged to secure a stable supply of farm produce.According to a document released after the annual Central Rural Work Conference held on December 22-23 in Beijing,preventing short supplies of farm produce and avoiding"ex-

  16. ABOUT SPONGE FARMING

    Directory of Open Access Journals (Sweden)

    Marijana Pećarević

    2005-04-01

    Full Text Available Sponges are the simplest multicellular animals. Farming of sponges is facilitated by their asexual reproduction and great ability of regeneration. Farming of filter-feeding sponges is environment friendly, and it can positively influence on environmental impact of other aquaculture activities. Natural populations of sponges in Mediterranean Sea are endangered by inappropriate overfishing. Farming of sponges is possible solution for regeneration and protection of natural populations.

  17. 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.

  18. 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

  19. Evaluation of Soil Moisture Retrieval from the ERS and Metop Scatterometers in the Lower Mekong Basin

    Directory of Open Access Journals (Sweden)

    Heiko Apel

    2013-03-01

    Full Text Available The natural environment and livelihoods in the Lower Mekong Basin (LMB are significantly affected by the annual hydrological cycle. Monitoring of soil moisture as a key variable in the hydrological cycle is of great interest in a number of Hydrological and agricultural applications. In this study we evaluated the quality and spatiotemporal variability of the soil moisture product retrieved from C-band scatterometers data across the LMB sub-catchments. The soil moisture retrieval algorithm showed reasonable performance in most areas of the LMB with the exception of a few sub-catchments in the eastern parts of Laos, where the land cover is characterized by dense vegetation. The best performance of the retrieval algorithm was obtained in agricultural regions. Comparison of the available in situ evaporation data in the LMB and the Basin Water Index (BWI, an indicator of the basin soil moisture condition, showed significant negative correlations up to R = −0.85. The inter-annual variation of the calculated BWI was also found corresponding to the reported extreme hydro-meteorological events in the Mekong region. The retrieved soil moisture data show high correlation (up to R = 0.92 with monthly anomalies of precipitation in non-irrigated regions. In general, the seasonal variability of soil moisture in the LMB was well captured by the retrieval method. The results of analysis also showed significant correlation between El Niño events and the monthly BWI anomaly measurements particularly for the month May with the maximum correlation of R = 0.88.

  20. Sand dynamic in the Mekong River channel and export to the coastal ocean

    Science.gov (United States)

    Stephens, J. D.; Allison, M. A.; Di Leonardo, D. R.; Weathers, H. D.; Ogston, A. S.; McLachlan, R. L.; Xing, F.; Meselhe, E. A.

    2017-09-01

    Two field campaigns were conducted in the tidal and estuarine reach of the Sông Hậu distributary of the Mekong River to explore the dynamics of sand transport and export to the coastal ocean. This study examines variations in suspended sand concentration and net flux of suspended and bedload sand with respect to changes in discharge between the October 2014 high discharge and March 2015 low discharge season. Isokinetic measurements of suspended sand were used to calibrate a larger dataset of LISST profiles to report suspended sand mass concentrations. During the high discharge season, ebb and flood currents are a primary control on suspended sand concentrations. Ebb tidal flows are more capable of sand transport than flooding flows, due to river discharge augmenting tidal currents. Sand in suspension is primarily derived locally from bed material sand. Bedform transport estimates were limited, but suggest that bedload sand transport is less than 10% of net suspended sand flux. Very low concentrations of suspended sand sediment are found during the low discharge season. These low concentrations are likely caused by (1) a reduction in maximum ebb tide shear stresses associated with less freshwater input, and (2) mud mantling in the bed associated with upstream migration of estuarine circulation, that inhibits local sourcing (resuspension) of bed sand. Results of the observational study were used to calibrate a numerical model of annual sand flux to the ocean from all distributaries of the Mekong River. Annual sand export is estimated at 6.5 ± 1.6 Mt yr-1. The Định An subdistributary accounts for 32% of this total while the smaller Trần Đề subdistributary accounts for only 9%.

  1. Inferring reservoir operating patterns across the Mekong Basin using only space observations

    Science.gov (United States)

    Bonnema, Matthew; Hossain, Faisal

    2017-05-01

    This study explores the operating pattern of artificial reservoirs by examining their impact on streamflow through two parameters, residence time and flow alteration, using a purely satellite-based technique for the Mekong Basin. Overall residence times of individual reservoirs ranged from 0.09 to 4.04 years, while streamflow was altered between 11 and 130% of its natural variability. The current set of reservoirs appears to have increased the residence time of the entire Mekong basin by about 1 month. However, if subbasin variability is considered, the satellite-based method depicts a different picture. Residence time increases to 4 months when only regulated flows are considered. If low residence time reservoirs on major rivers are excluded and reservoirs on higher stream-order rivers considered, residence time increases to 1.3 years. Predictable strong seasonal patterns emerged in residence time, where reservoirs experience higher residence time in the dry season and lower residence time in the wet season and residence time varies inversely with precipitation. High variability in reservoir effects on streamflow between reservoirs could not be explained by any reservoir properties (e.g., size, use, location, etc.), highlighting the variability in the human decisions operating these reservoirs. The take-home message of this study is that satellite observations, in combination with physical models forced with satellite data, can elucidate the spatiotemporal variability of reservoir behavior in ungauged basins of the developing world. We demonstrate in this study that the requirement for ground data to monitor current or historical behavior of dams is not necessary.

  2. Sediment dynamics in the lower Mekong River: Transition from tidal river to estuary

    Science.gov (United States)

    Nowacki, Daniel J.; Ogston, Andrea S.; Nittrouer, Charles A.; Fricke, Aaron T.; Van, Pham Dang Tri

    2015-09-01

    A better understanding of flow and sediment dynamics in the lowermost portions of large-tropical rivers is essential to constraining estimates of worldwide sediment delivery to the ocean. Flow velocity, salinity, and suspended-sediment concentration were measured for 25 h at three cross sections in the tidal Song Hau distributary of the Mekong River, Vietnam. Two campaigns took place during comparatively high-seasonal and low-seasonal discharge, and estuarine conditions varied dramatically between them. The system transitioned from a tidal river with ephemeral presence of a salt wedge during high flow to a partially mixed estuary during low flow. The changing freshwater input, sediment sources, and estuarine characteristics resulted in seaward sediment export during high flow and landward import during low flow. The Dinh An channel of the Song Hau distributary exported sediment to the coast at a rate of about 1 t s-1 during high flow and imported sediment in a spatially varying manner at approximately 0.3 t s-1 during low flow. Scaling these values results in a yearly Mekong sediment discharge estimate about 65% smaller than a generally accepted estimate of 110 Mt yr-1, although the limited temporal and spatial nature of this study implies a relatively high degree of uncertainty for the new estimate. Fluvial advection of sediment was primarily responsible for the high-flow sediment export. Exchange-flow and tidal processes, including local resuspension, were principally responsible for the low-flow import. The resulting bed-sediment grain size was coarser and more variable during high flow and finer during low, and the residual flow patterns support the maintenance of mid-channel islands. This article was corrected on 7 OCT 2015. See the end of the full text for details.

  3. Palaeoclimatological perspective on river basin hydrometeorology: case of the Mekong Basin

    Science.gov (United States)

    Räsänen, T. A.; Lehr, C.; Mellin, I.; Ward, P. J.; Kummu, M.

    2013-05-01

    Globally, there have been many extreme weather events in recent decades. A challenge has been to determine whether these extreme weather events have increased in number and intensity compared to the past. This challenge is made more difficult due to the lack of long-term instrumental data, particularly in terms of river discharge, in many regions including Southeast Asia. Thus our main aim in this paper is to develop a river basin scale approach for assessing interannual hydrometeorological and discharge variability on long, palaeological, time scales. For the development of the basin-wide approach, we used the Mekong River basin as a case study area, although the approach is also intended to be applicable to other basins. Firstly, we derived a basin-wide Palmer Drought Severity Index (PDSI) from the Monsoon Asia Drought Atlas (MADA). Secondly, we compared the basin-wide PDSI with measured discharge to validate our approach. Thirdly, we used basin-wide PDSI to analyse the hydrometeorology and discharge of the case study area over the study period of 1300-2005. For the discharge-MADA comparison and hydrometeorological analyses, we used methods such as linear correlations, smoothing, moving window variances, Levene type tests for variances, and wavelet analyses. We found that the developed basin-wide approach based on MADA can be used for assessing long-term average conditions and interannual variability for river basin hydrometeorology and discharge. It provides a tool for studying interannual discharge variability on a palaeological time scale, and therefore the approach contributes to a better understanding of discharge variability during the most recent decades. Our case study revealed that the Mekong has experienced exceptional levels of interannual variability during the post-1950 period, which could not be observed in any other part of the study period. The increased variability was found to be at least partly associated with increased El Niño Southern

  4. Assessing Malaria Risks in Greater Mekong Subregion based on Environmental Parameters

    Science.gov (United States)

    Kiang, Richard; Soika, Valerii; Adimi, Farida; Nigro, Joseph

    2005-01-01

    At 4,200 km, the Mekong River is the tenth longest river in the world. It directly and indirectly influences the lives of hundreds of millions of inhabitants in its basin. The riparian countries - Thailand, Myanmar, Cambodia, Laos, Vietnam, and a small part of China - form the Greater Mekong Subregion (GMS). This geographical region has the misfortune of being the world's epicenter of falciparum malaria, which is the most severe form of malaria caused by Plasmodium falciparum. Depending on the country, approximately 50 to 90% of all malaria cases are due to this species. In the Malaria Modeling and Surveillance Project, we have been developing techniques to enhance public health s decision capability for malaria risk assessments and controls. The main objectives are: 1) identifying the potential breeding sites for major vector species; 2) implementing a malaria transmission model to identify the key factors that sustain or intensify malaria transmission; and 3) implementing a risk algorithm to predict the occurrence of malaria and its transmission intensity. The potential benefits are: 1) increased warning time for public health organizations to respond to malaria outbreaks; 2) optimized utilization of pesticide and chemoprophylaxis; 3) reduced likelihood of pesticide and drug resistance; and 4) reduced damage to environment. Environmental parameters important to malaria transmission include temperature, relative humidity, precipitation, and vegetation conditions. The NASA Earth science data sets that have been used for malaria surveillance and risk assessment include AVHRR Pathfinder, TRMM, MODIS, NSIPP, and SIESIP. Hindcastings based on these environmental parameters have shown good agreement to epidemiological records. Socioeconomic factors that may influence malaria transmissions will also be incorporated into the predictive models.

  5. Assessing Malaria Risks in Greater Mekong Subregion based on Environmental Parameters

    Science.gov (United States)

    Kiang, Richard; Soika, Valerii; Adimi, Farida; Nigro, Joseph

    2005-01-01

    At 4,200 km, the Mekong River is the tenth longest river in the world. It directly and indirectly influences the lives of hundreds of millions of inhabitants in its basin. The riparian countries - Thailand, Myanmar, Cambodia, Laos, Vietnam, and a small part of China - form the Greater Mekong Subregion (GMS). This geographical region has the misfortune of being the world's epicenter of falciparum malaria, which is the most severe form of malaria caused by Plasmodium falciparum. Depending on the country, approximately 50 to 90% of all malaria cases are due to this species. In the Malaria Modeling and Surveillance Project, we have been developing techniques to enhance public health s decision capability for malaria risk assessments and controls. The main objectives are: 1) identifying the potential breeding sites for major vector species; 2) implementing a malaria transmission model to identify the key factors that sustain or intensify malaria transmission; and 3) implementing a risk algorithm to predict the occurrence of malaria and its transmission intensity. The potential benefits are: 1) increased warning time for public health organizations to respond to malaria outbreaks; 2) optimized utilization of pesticide and chemoprophylaxis; 3) reduced likelihood of pesticide and drug resistance; and 4) reduced damage to environment. Environmental parameters important to malaria transmission include temperature, relative humidity, precipitation, and vegetation conditions. The NASA Earth science data sets that have been used for malaria surveillance and risk assessment include AVHRR Pathfinder, TRMM, MODIS, NSIPP, and SIESIP. Hindcastings based on these environmental parameters have shown good agreement to epidemiological records. Socioeconomic factors that may influence malaria transmissions will also be incorporated into the predictive models.

  6. Farm Health and Safety

    Science.gov (United States)

    ... jobs in the United States. Farms have many health and safety hazards, including Chemicals and pesticides Machinery, ... equipment can also reduce accidents. Occupational Safety and Health Administration

  7. Valley Fever (Coccidioidomycosis) Statistics

    Science.gov (United States)

    ... farm workers, 11 and in people exposed to earthquakes 12 and dust storms. 13 If you live ... al. A coccidioidomycosis outbreak following the Northridge, Calif, earthquake. JAMA. 1997 Mar 19;277(11):904-8. ...

  8. GEOMORPHOLOGICAL FEATURES AND SUBSURFACE GEOLOGY OF THE LOWER MEKONG PLAIN AROUND PHNOM PENH CITY, CAMBODIA (SOUTHEAST ASIA

    Directory of Open Access Journals (Sweden)

    Sumiko Kubo

    2008-06-01

    Full Text Available The geomorphological features of the Lower Mekong Plain and their relationships with floods, as well asthe subsurface geology and the major depositional processes in the area, are discussed. From theinterpretation of aerial photos and field reconnaissance, the Lower Mekong Plain in Cambodia ischaracterized as a floodplain with natural levees and back marshes. These geomorphological featuresinfluence the extent of the extensive inundation that occurs during every rainy (wet season. An extremeflood in 2000 confirmed the close relationship between micro-landforms and the flooding. A preliminarystudy of bore-hole logs in the area of Phnom Penh was also carried out. Base rocks are shallower in thewestern part, whereas thick (>130 m Quaternary deposits occur in the eastern part, suggesting the presenceof a structural basin.

  9. Valley-contrasting orbital angular momentum in photonic valley crystals

    CERN Document Server

    Chen, Xiaodong; Dong, Jianwen

    2016-01-01

    Valley, as a degree of freedom, has been exploited to realize valley-selective Hall transport and circular dichroism in two-dimensional layered materials. On the other hand, orbital angular momentum of light with helical phase distribution has attracted great attention for its unprecedented opportunity to optical communicagtions, atom trapping, and even nontrivial topology engineering. Here, we reveal valley-contrasting orbital angular momentum in all-dielectric photonic valley crystals. Selective excitation of valley chiral bulk states is realized by sources carrying orbital angular momentum with proper chirality. Valley dependent edge states, predictable by nonzero valley Chern number, enable to suppress the inter-valley scattering along zigzag boundary, leading to broadband robust transmission in Z-shape bend without corner morphological optimization. Our work may open up a new door towards the discovery of novel quantum states and the manipulation of spin-orbit interaction of light in nanophotonics.

  10. ANALYSIS OF THE PROCESSES AND TRANSFORMATIONS OF THE DENUNDATION VALLEYS IN THE BIELSK PLAIN

    Directory of Open Access Journals (Sweden)

    Krzysztof Micun

    2015-07-01

    Full Text Available The aim of the study was to recognise natural and anthropogenic transformations taking place in small denudation valleys in the old glacial landscape of the Bielsk Plain. The changes are registered in sediments of the valleys. The Bielsk Plain area situated in the north of Bielsk Podlaski is characterized by the presence of latitudinal running denudation valleys, that end with concave broadenings in their headwaters. The geological structure is dominated by silt deposits of various origins. Tills are present in the hilltops while organic and organo-mineral deposits in the depressions. The thickness of the deluvial deposits in the valleys reaches 2 m though usually it does not exceed 1 m. The deposits are mostly silts that developed lithologically as sandy dust and loam dust. Colluvium sedimentation in the valleys clearly correlates with the development of agriculture, deforestation and farming in the area. The abandonment of the cultivation causes significant slowdown in the pace of accumulation of colluvium sediments.

  11. 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

    2013-01-01

    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. PMID:23926362

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

    Directory of Open Access Journals (Sweden)

    H. Apel

    2015-08-01

    Full Text Available 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

  13. Piped-Water Supplies in Rural Areas of the Mekong Delta, Vietnam: Water Quality and Household Perceptions

    OpenAIRE

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

    2014-01-01

    In the Mekong Delta (MD) in Vietnam, piped-water supply stations are being intensively built to reach the millennium development goal (MDG) to provide safe and clean drinking water resources to communities. However, studies focusing on the effectiveness of supply stations in reaching these goals are scarce to date. Water samples from 41 water supply stations in the MD were collected between June and October 2012. Water samples were analyzed for general parameters, salinity, nutrients, metal(l...

  14. Extreme floods in the Mekong River Delta under climate change: combined impacts of upstream hydrological changes and sea level rise

    Science.gov (United States)

    Hoang, Long; Nguyen Viet, Dung; Kummu, Matti; Lauri, Hannu; Koponen, Jorma; van Vliet, Michelle T. H.; Supit, Iwan; Leemans, Rik; Kabat, Pavel; Ludwig, Fulco

    2016-04-01

    Extreme floods cause huge damages to human lives and infrastructure, and hamper socio-economic development in the Mekong River Delta in Vietnam. Induced by climate change, upstream hydrological changes and sea level rise are expected to further exacerbate future flood hazard and thereby posing critical challenges for securing safety and sustainability. This paper provides a probabilistic quantification of future flood hazard for the Mekong Delta, focusing on extreme events under climate change. We developed a model chain to simulate separate and combined impacts of two drivers, namely upstream hydrological changes and sea level rise on flood magnitude and frequency. Simulation results show that upstream changes and sea level rise substantially increase flood hazard throughout the whole Mekong Delta. Due to differences in their nature, two drivers show different features in their impacts on floods. Impacts of upstream changes are more dominant in floodplains in the upper delta, causing an increase of up to +0.80 m in flood depth. Sea level rise introduces flood hazard to currently safe areas in the middle and coastal delta zones. A 0.6 m rise in relative sea level causes an increase in flood depth between 0.10 and 0.70 m, depending on location by 2050s. Upstream hydrological changes and sea level rise tend to intensify each other's impacts on floods, resulting in stronger combined impacts than linearly summed impacts of each individual driver. Substantial increase of future flood hazard strongly requires better flood protection and more flood resilient development for the Mekong Delta. Findings from this study can be used as quantified physical boundary conditions to develop flood management strategies and strategic delta management plans.

  15. Analyzing farming systems diversity: a case study in south-western France

    Energy Technology Data Exchange (ETDEWEB)

    Choisis, J. P.; Thevenet, C.; Girbon, A.

    2012-11-01

    The huge changes in agricultural activities, which may be amplified by the forthcoming Common Agriculture Policy reform, call the future of crop-livestock systems into question and hence the impact of these changes on landscapes and biodiversity. We analyzed relationships between agriculture, landscape and biodiversity in south-western France. The study area covered about 4,000 ha and included four villages. We conducted a survey of 56 farms. Multivariate analysis (multiple factor analysis and cluster analysis) were used to analyze relationships between 25 variables and to build a typology. The type of farming (beef and/or dairy cattle, cash crops), size (area and workforce) and cultivation practices, among others, were revealed as differentiating factors of farms. Six farming types were identified (1) hillside mixed crop-livestock farms, (2) large corporate farms, (3) extensive cattle farms, (4) large intensive farms on the valley sides, (5) small multiple-job holdings, and (6) hobby farms. The diversity of farming systems revealed the variable impact of the main drivers of change affecting agricultural development, particularly the enlargement and modernization of farms along with the demography of agricultural holdings. (Author) 41 refs.

  16. Migrant Farm Workers.

    Science.gov (United States)

    Slesinger, Doris P.; Pfeffer, Max J.

    This paper documents migrant farm workers as being among the most persistently underprivileged groups in American society. Migrant farm workers typically receive low wages from irregular employment and live in poverty with access to only substandard housing and inadequate health care. The lack of economic improvement stems from a number of…

  17. Not Your Family Farm

    Science.gov (United States)

    Tenopir, Carol; Baker, Gayle; Grogg, Jill E.

    2007-01-01

    The information industry continues to consolidate, just as agribusiness has consolidated and now dominates farming. Both the family farm and the small information company still exist but are becoming rarer in an age of mergers, acquisitions, and increased economies of scale. Small companies distinguish themselves by high quality, special themes,…

  18. 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.

  19. Assessment of changes in riverine nitrate in the Sesan, Srepok and Sekong tributaries of the Lower Mekong River Basin

    Directory of Open Access Journals (Sweden)

    Chantha Oeurng

    2016-12-01

    Full Text Available Changes in nitrates are of particular concern in tropical regions undergoing rapid development, as these changes may affect local and downstream riverine ecosystems. This study assessed the spatial and temporal differences in nitrate loads within the Sesan, Srepok, and Sekong (3S Rivers, the largest tributaries of the Mekong River. Simulation results from a flow and nitrate calibrated SWAT model show large differences in year-to-year nitrate loads, a strong seasonality, and clear variability patterns in monthly nitrate loads in the 3S outlet during the wet season. The annual total nitrate loading from the 3S Rivers account for approximately 30% of the total nitrate load of the Mekong River at Pakse. Nitrate loads during the rainy season accounts for 79% of the total annual load into the Mekong River. The Sesan, Sekong, and Srepok basins have average nitrate yields of 400, 330, and 290 kg N/km2, respectively, which is comparable with other forested catchments, but much lower than agriculture dominated catchments in the tropics. Simulations of three future climate scenarios show little variability in annual nitrate loadings under current land use/land cover (LULC, but seasonal difference in nitrate loading during rainy months was observed. Further research is needed to estimate nitrate loads in the 3S basin as influenced by LULC change and dam development, which may potentially result in complex changes to local and downstream riverine ecosystems.

  20. High genetic diversity in cryptic populations of the migratory sutchi catfish Pangasianodon hypophthalmus in the Mekong River.

    Science.gov (United States)

    So, N; Maes, G E; Volckaert, F A M

    2006-02-01

    The detection and conservation of spawning units is of crucial importance in highly migratory species. The sutchi catfish Pangasianodon hypophthalmus (Pangasiidae; Teleostei) is a common large-sized tropical fish, which migrates annually to several upstream spawning sites on the Lower Mekong River and feeds on the huge floodplain of the Lower Mekong and Tonle Sap for the other half of the year. We hypothesised that because of the relative size of the feeding and spawning habitat, genetic variability would be high and homogeneous in foraging populations, but that spawning stocks would be distinct in space and time. To test these predictions, 567 individuals from 10 geographic locations separated by up to 1230 km along the Lower Mekong River were genotyped at seven microsatellite loci. The level of genetic diversity was much higher than other freshwater fish and reached values comparable to marine species (mean H(e)=0.757). All samples collected at the potential spawning sites deviated from Hardy-Weinberg expectations, suggesting admixture. Individual-based clustering methods revealed genetic heterogeneity and enabled the detection of three genetically distinct sympatric populations. There was no evidence of recent reduction in effective population size in any population. Contrasting with the vast extent of the feeding grounds, the shortage of spawning grounds seems to have moved sutchi catfish towards diachronous spawning. Hence the sustainable exploitation of this natural resource hinges on the conservation of the limited spawning grounds and open migration routes between the spawning and feeding grounds.

  1. Monophyly of Opisthorchis viverrini populations in the lower Mekong Basin, using mitochondrial DNA nad1 gene as the marker.

    Science.gov (United States)

    Thaenkham, Urusa; Nuamtanong, Supaporn; Sa-nguankiat, Surapol; Yoonuan, Tippayarat; Touch, Sarun; Manivong, Khemphavanh; Vonghachack, Youthanavanh; Sato, Megumi; Waikagul, Jitra

    2010-06-01

    The liver fluke, Opisthorchis viverrini, causes serious public-health problems in the Lower Mekong Basin. This study aimed to clarify whether O. viverrini populations may be genetically divided into sub-specific taxa. We collected 6 populations of O. viverrini from different places in Cambodia, Lao PDR, and Thailand, along both sides of the Mekong River, and analyzed the population structure of these using the mitochondrial nad1 gene as a marker. The results of the DNA polymorphism measurements, by theta-w (thetaw) and -pi (thetapi) values, neutrality tests, and mismatch distribution, suggested that the population of O. viverrini has expanded under the influence of purifying selection and selective sweep. The analysis of molecular variance (AMOVA) test revealed no significant genetic differences among the O. viverrini populations on opposite sides of the Mekong River. O. viverrini haplotypes occurred in multiple populations, and no distinct geographical clade. The star-like haplotype network confirmed a demographic expansion of the O. viverrini population. Overall, the genetic data from these populations suggested that the postulated existence of an O. viverrini species complex should be rejected. The bio-geographical diversity of O. viverrini populations should be explored further, using other appropriate markers and a wider range of samples from geographically different areas.

  2. Multi-model ensemble simulation and projection in the climate change in the Mekong River Basin. Part I: temperature.

    Science.gov (United States)

    Huang, Yong; Wang, Fengyou; Li, Yi; Cai, Tijiu

    2014-11-01

    This paper evaluates the performance of the Coupled Model Intercomparison Project phase 5 (CMIP5) in simulating annual and decadal temperature in the Mekong River Basin from 1950 to 2005. By use of Bayesian multi-model averaging method, the future projection of temperature variation under different scenarios are also analyzed. The results show, the performances of climate model are more accurate in space than time, the model can catch the warming characteristics in the Mekong river Basin, but the accuracy of simulation is not good enough. Bayesian multi-model averaging method can improve the annual and decadal temperature simulation when compared to a single result. The projected temperature in Mekong River will increase by 0.88 °C/100 year, 2.15 °C/100 year and 4.96 °C/100 year for the RCP2.6, RCP4.5, and RCP8.5 scenarios, respectively, over the twenty-first century. The findings will be beneficial for local people and policy-maker to formulate regional strategies against the potential menaces of warming scenarios.

  3. Investigation of Dairy Farm Silage Emissions

    Science.gov (United States)

    McCluskey, C. S.; Blake, D. R.; Yang, M. M.; Dehart, J.

    2009-12-01

    California’s Central Valley is one of the most ozone polluted areas in the United States. For better understanding of the sources of this increasing tropospheric ozone concentration, an experiment was conducted on a dairy farm located in the central valley area. Dairy farm silage is a suspected source of tropospheric ozone due to recent findings of ethanol emissions resulting from the fermentation process that occurs during the preparation of silage. However, a silage pile consists of three main layers and each layer has different physical and chemical properties. During the distribution period, the inner layer is most exposed. This experiment was focused on wheat silage, and different layers of the individual silage pile were tested to investigate their emissions. Samples were collected using air canisters and analyzed via FID gas chromatography in the University of California Irvine Rowland/Blake Lab. The samples collected did reveal ethanol concentrations, and a difference was observed between the layers of the silage pile. The dry outer layer of the pile had a smaller amount of gaseous emissions than the inner “moist” section of the pile. Additionally, an unexpected peak in the inner layer’s chromatogram showed a propyl alcohol concentration of 28,000 ppbv in comparison to an ethanol concentration of 15,000 ppbv. Propyl alcohol has a higher Maximum Incremental Reactivity (MIR) value, than that of ethanol. MIR is a numerical value assigned to compounds based on their ozone forming potential. Therefore, a high concentration of propyl alcohol in silage is probable to be a contributor to the tropospheric ozone concentration in the atmosphere. The information provided by this research experiment can induce further research on dairy farm emissions. Continuing this research could potentially provide scientific information required to create regulations.

  4. Detection of Area Changes in River Mouthbars at the Mekong River Delta using ALOS/PALSAR data

    Science.gov (United States)

    Tanaka, A.; Uehara, K.; Tamura, T.; Saito, Y.

    2011-12-01

    Projected sea-level rise by the year 2100 would be ~1m recently and its negative impact on the coastal zone has been pointed out, particularly for mega-deltas in Asia by the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC, 2007). The relative sea-level rise varies with specific conditions and processes over broad spatial and temporal scales. Therefore, long-term monitoring of geomorphological changes in coastal areas over wide areas is of highly interest and importance for coastal management. However, due to limited data availability and accessibility in developing countries, there is not enough systematic coastal monitoring. The Mekong River Delta is one of typical mega-deltas in Asia, which has a low-lying wide delta-plain located in Cambodia to South Vietnam. Sediment and water discharges of the Mekong River are controlled by the monsoon with high and low discharge in summer (wet season) and winter (dry season), respectively. Therefore, technologies such as SAR (Synthetic Aperture Radar) not affected by the cloud conditions offer potential for monitoring in the monsoon Asia region. In this study, ALOS (Advanced Land Observing Satellite) PALSAR (Phased Array type L-band SAR) data acquired over a period from December 2006 to January 2011 are analyzed to investigate the relation between the sea level and the shape of mouthbars in the Mekong River. Level-1.0 PALSAR data were processed, coregistered, and geocoded to make SAR backscatter intensity images. River mouthbars with strong backscatter, which is surrounded by the water with weak backscatter, are successfully extracted using a histogram thresholding algorithm. Estimated areas of river mouthbars, which are located at the central part of the delta and openly faced to the South China Sea, gradually increase on an annual time scale. These river mouthbars are growing to the seaward. Besides this overall increasing trend, seasonal variations of areas are observed; these correlate with

  5. Silicon Valley's Turnaround

    Institute of Scientific and Technical Information of China (English)

    Joseph Leu

    2006-01-01

    @@ During Silicon Valley's dramatic economic growth fueled by the Internet boom and business investment in information technology, employment in the region's high-tech sec tor tripled between 1995 and 2000. The economic boom gave rise to many new firms,drawing em ployees into high-tech jobs from other regions and other industries.

  6. Breathing Valley Fever

    Centers for Disease Control (CDC) Podcasts

    2014-02-04

    Dr. Duc Vugia, chief of the Infectious Diseases Branch in the California Department of Public Health, discusses Valley Fever.  Created: 2/4/2014 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 2/5/2014.

  7. Boyne Valley Tombs

    Science.gov (United States)

    Prendergast, Frank

    The passage tombs of the Boyne Valley exhibit the greatest level of development of the megalithic tomb building tradition in Ireland in terms of their morphology, embellishment, burial tradition, grave goods, clustering, and landscape siting. This section examines these characteristics and gives a summary archaeoastronomical appraisal of their orientation and detected astronomical alignment.

  8. Red (Planet) River Valleys

    Institute of Scientific and Technical Information of China (English)

    陈淑娴

    1995-01-01

    Mars today is a frozen desert,but the photos sent back by the Mariner and Viking probes in the 1970s indicate its past was less bleak and more Earth-like. The images showed sinuous channels and valleys that were al-

  9. Installation and Implementation of a Comprehensive Groundwater Monitoring Program for the Indian Wells Valley, California

    Science.gov (United States)

    2010-04-01

    Community Services District, Kern County Water Agency, Naval Air Weapons Station/China Lake, Searles Valley Minerals, the City of Ridgecrest, Quist ...MINERALS ( .~.~ INDIAN ~S V ALLEY AIRPORT ~ ൓ ~twWv ~ QUIST FARMS By: JAN 31 2006 Chairman, Board of Supervisors APPROVED AS TO CONTENT

  10. 77 FR 214 - Revisions to the California State Implementation Plan, San Joaquin Valley Unified Air Pollution...

    Science.gov (United States)

    2012-01-04

    ... Air Pollution Control District (SJVUAPCD) AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: EPA is finalizing approval of revisions to the San Joaquin Valley Air Pollution Control... and air districts for evaluating air pollution control economics. 3. Farms can change owners...

  11. Bringing Silicon Valley inside.

    Science.gov (United States)

    Hamel, G

    1999-01-01

    In 1998, Silicon Valley companies produced 41 IPOs, which by January 1999 had a combined market capitalization of $27 billion--that works out to $54,000 in new wealth creation per worker in a single year. Multiply the number of employees in your company by $54,000. Did your business create that much new wealth last year? Half that amount? It's not a group of geniuses generating such riches. It's a business model. In Silicon Valley, ideas, capital, and talent circulate freely, gathering into whatever combinations are most likely to generate innovation and wealth. Unlike most traditional companies, which spend their energy in resource allocation--a system designed to avoid failure--the Valley operates through resource attraction--a system that nurtures innovation. In a traditional company, people with innovative ideas must go hat in hand to the guardians of the old ideas for funding and for staff. But in Silicon Valley, a slew of venture capitalists vie to attract the best new ideas, infusing relatively small amounts of capital into a portfolio of ventures. And talent is free to go to the companies offering the most exhilarating work and the greatest potential rewards. It should actually be easier for large, traditional companies to set up similar markets for capital, ideas, and talent internally. After all, big companies often already have extensive capital, marketing, and distribution resources, and a first crack at the talent in their own ranks. And some of them are doing it. The choice is yours--you can do your best to make sure you never put a dollar of capital at risk, or you can tap into the kind of wealth that's being created every day in Silicon Valley.

  12. 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

  13. Observing farming systems

    DEFF Research Database (Denmark)

    Noe, Egon; Alrøe, Hugo Fjelsted

    2012-01-01

    In Denmark, agriculture is becoming increasingly specialised, and more and more actors are becoming involved in farm decision making. These trends are more or less pronounced in other European countries as well. We therefore find that to understand modern farming systems, we have to shift the focus...... of analysis from individual farmers to communication and social relations. This is where Luhmann’s social systems theory can offer new insights. Firstly, it can help observe and understand the operational closure and system logic of a farming system and how this closure is produced and reproduced. Secondly...

  14. Wind farm design optimization

    Energy Technology Data Exchange (ETDEWEB)

    Carreau, Michel; Morgenroth, Michael; Belashov, Oleg; Mdimagh, Asma; Hertz, Alain; Marcotte, Odile

    2010-09-15

    Innovative numerical computer tools have been developed to streamline the estimation, the design process and to optimize the Wind Farm Design with respect to the overall return on investment. The optimization engine can find the collector system layout automatically which provide a powerful tool to quickly study various alternative taking into account more precisely various constraints or factors that previously would have been too costly to analyze in details with precision. Our Wind Farm Tools have evolved through numerous projects and created value for our clients yielding Wind Farm projects with projected higher returns.

  15. 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

  16. Gendering Cross-Border Networks in the Greater Mekong Subregion: Drawing Invisible Routes to Thailand

    Directory of Open Access Journals (Sweden)

    AKM Ahsan Ullah

    2011-01-01

    Full Text Available This article discusses human traffi cking within the Greater Mekong Subregion (GMS in relation to the strengthened inter-state economic and infrastructural co-operation and connectivity, taking the life history of sex workers in Thailand into account. Over the last decades, Thailand became known as a hub of entertainment sectors. Traffi ckers often use socio-economic integration in the GMS to their advantage. A large number of trafficked women ends up in the Thai entertainment industry doing sex work in confi ned conditions similar to slavery. Poor women are often lured by false promises of well-paid jobs abroad and pay exorbitant fees to agents for such an opportunity. Intermediaries introduce family members to agents who promise to make arrangements for the relevant documentation and transportation across borders. Traffickers use their own marked routes to transport their prey which are more invisible than generally could be imagined. ----- Der vorliegende Beitrag betrachtet den Menschenhandel in der Greater Mekong Subregion (GMS unter Berücksichtigung der Stärkung zwischenstaatlicher wirtschaftlicher und infrastruktureller Kooperation und Vernetzung. Dabei nimmt er Lebensgeschichten Prostituierter in Thailand genauer unter die Lupe. Im Laufe der Jahre wurde Thailand als Drehscheibe des Unterhaltungssektors berühmt. Es ist jedoch weitgehend unbekannt, dass eine Großzahl der Opfer des Menschenhandels in der Sexarbeit und in der Sklaverei ähnlichen Arbeitsverhältnissen landet. Menschenhändler nützen die sozioökonomische Integration in der GMS zu ihrem Vorteil. Diese Studie zeigt, dass von Armut betroff ene Frauen in der Regel durch falsche Versprechungen gut bezahlter Arbeitsplätze ins Ausland gelockt werden und für solche Gelegenheiten exorbitante Gebühren an ihre Agenten bezahlen. Vermittler bringen Familienmitglieder und Agenten zusammen, welche die entsprechenden Unterlagen vorbereiten um den Transport über den Grenz

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

    Science.gov (United States)

    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

  18. 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

  19. 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

  20. Rainfed farming systems

    National Research Council Canada - National Science Library

    Tow, P. G

    2011-01-01

    "While agriculturists need a good grasp of the many separate aspects of agriculture, it is essential that they also understand the functioning of farming systems as a whole and how they can be best managed...

  1. FarmStats_CNTYFARM

    Data.gov (United States)

    Vermont Center for Geographic Information — This datalayer contains Vermont agricultural data describing changes in farming activity (1860-1997), by county, extracted from U.S. Census of Agriculture. Initial...

  2. Agriculture: Organic Farming

    Science.gov (United States)

    Organic Farming - Organically grown food is food grown and processed using no synthetic fertilizers or pesticides. Pesticides derived from natural sources (such as biological pesticides) may be used in producing organically grown food.

  3. CONTRACT BROILER FARMING

    Directory of Open Access Journals (Sweden)

    Todsadee Areerat

    2012-01-01

    Full Text Available In Thailand, poultry sector is the main economic growth of livestock sector, especially broiler production. The rapid expansion in broiler production has been made possible by the increase in the number of commercial farms or contract farming. The objective of this research was to understand better how contract farming works, who gets involved and why and who benefits from the agreement. The study is based on the broiler file survey in Chiang Mai province of Thailand. As the results, contract farming looks quite attractive for farmers as well as for private companies but most of the farmers complained about long waiting until the delivery of the next cycle of chicks have started.

  4. Farming techniques for seaweeds

    OpenAIRE

    Castaños, M.; Buendia, R.

    1998-01-01

    Details are given of farming methods developed by the SEAFDEC Aquaculture Department for 3 different seaweeds: 1) Bottom line culture method for Kappaphycus; 2) Pond culture of Gracilaria; and, 3) Gracilariopsis bailinae, the new seaweed on the block.

  5. Summary of Data Farming

    Directory of Open Access Journals (Sweden)

    Gary Horne

    2016-03-01

    Full Text Available Data Farming is a process that has been developed to support decision-makers by answering questions that are not currently addressed. Data farming uses an inter-disciplinary approach that includes modeling and simulation, high performance computing, and statistical analysis to examine questions of interest with a large number of alternatives. Data farming allows for the examination of uncertain events with numerous possible outcomes and provides the capability of executing enough experiments so that both overall and unexpected results may be captured and examined for insights. Harnessing the power of data farming to apply it to our questions is essential to providing support not currently available to decision-makers. This support is critically needed in answering questions inherent in the scenarios we expect to confront in the future as the challenges our forces face become more complex and uncertain. This article was created on the basis of work conducted by Task Group MSG-088 “Data Farming in Support of NATO”, which is being applied in MSG-124 “Developing Actionable Data Farming Decision Support for NATO” of the Science and Technology Organization, North Atlantic Treaty Organization (STO NATO.

  6. The use of geothermal energy at a chieftan's farm in medieval Iceland

    Directory of Open Access Journals (Sweden)

    Gudrun Sveinbjarnardottir

    2003-10-01

    Full Text Available Archaeological investigations at the farm site of Reykholt, in the Reykholtsdalur valley in western Iceland (Fig. 1 , have produced evidence of sophisticated use of geothermal energy in the medieval period that is unmatched by comparable finds elsewhere in this geothermally and volcanically active country.

  7. Off-farm employment and income poverty in favourable agro-climatic areas of Tanzania

    DEFF Research Database (Denmark)

    Msinde, John Victor; Urassa, Justin K.; Nathan, Iben

    2016-01-01

    in the first quarter of 2014 in five villages of Kilombero Valley, Tanzania using a structured questionnaire. Income poverty was analysed using the Foster-Greer-Thorbecke (FGT) poverty index and two stage least square (2SLS) regression. Households with off-farm employment income were found to be less poor...

  8. Decisive key-factors influencing farm households' soil and water conservation investments

    NARCIS (Netherlands)

    Kessler, A.

    2006-01-01

    In the inter-Andean valleys of Bolivia decisive key-factors influencing farm households' soil and water conservation investments were determined. The household's progressiveness most influences the decision how much to invest; dynamic and responsible families are among the first. Economic stratum is

  9. Simulation and analysis of conjunctive use with MODFLOW's farm process.

    Science.gov (United States)

    Hanson, R T; Schmid, W; Faunt, C C; Lockwood, B

    2010-01-01

    The extension of MODFLOW onto the landscape with the Farm Process (MF-FMP) facilitates fully coupled simulation of the use and movement of water from precipitation, streamflow and runoff, groundwater flow, and consumption by natural and agricultural vegetation throughout the hydrologic system at all times. This allows for more complete analysis of conjunctive use water-resource systems than previously possible with MODFLOW by combining relevant aspects of the landscape with the groundwater and surface water components. This analysis is accomplished using distributed cell-by-cell supply-constrained and demand-driven components across the landscape within "water-balance subregions" comprised of one or more model cells that can represent a single farm, a group of farms, or other hydrologic or geopolitical entities. Simulation of micro-agriculture in the Pajaro Valley and macro-agriculture in the Central Valley are used to demonstrate the utility of MF-FMP. For Pajaro Valley, the simulation of an aquifer storage and recovery system and related coastal water distribution system to supplant coastal pumpage was analyzed subject to climate variations and additional supplemental sources such as local runoff. For the Central Valley, analysis of conjunctive use from different hydrologic settings of northern and southern subregions shows how and when precipitation, surface water, and groundwater are important to conjunctive use. The examples show that through MF-FMP's ability to simulate natural and anthropogenic components of the hydrologic cycle, the distribution and dynamics of supply and demand can be analyzed, understood, and managed. This analysis of conjunctive use would be difficult without embedding them in the simulation and are difficult to estimate a priori.

  10. Climate Change Impact On Mekong Delta of Vietnam in recent years

    Science.gov (United States)

    Le, L. T. X., III

    2015-12-01

    In recent years, the climate change signal increase globally. Abnormal changes of weather tends increasingly detrimental to human life, such as natural disasters occur with increasing level of more severe. Climate change is one the biggest challenges, and is a potential threat to humans. The impact of climate change increases the number and extent of the disaster fierce exists as typhoons, floods, droughts ... Global warming and sea level rise increases the area of flooding, saline intrusion and erosion in the delta region may cause farmers to lose the opportunity to produce, source of life their only. Impact of climate change on people in the community, but poor farmers in the developing countries like our country, women are the most severe consequences In this section, we summarize changes in climate on the territory of Vietnam, especially in Mekong Delta evaluate causes and its relationship to changes in global climate and region. Along with the analysis of characteristics of climate changes over time and through space to help the evolution of the standard deviation (average deviation from the standard of the period from 1971 to 2015) may indicate that the characteristic gas scenes took place related to global climate change ... Vietnam's territory stretches over approximately 15 latitude, the terrain is very complex, located in the interior full of tropical Southeast Asia. Vietnam climate strongly influenced by the Asian monsoon, monsoon and Northern Hemisphere especially the ENSO activity in the equatorial region and the Pacific Ocean. Climate Vietnam abundant and diversified, with strong ties to the region and globally.

  11. 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)

  12. 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.

  13. 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.

  14. From Risk Towards Resilience: Assessing Vulnerability and Adaptability to Climate Change in the Mekong Delta

    Science.gov (United States)

    Ling, F. H.; Yasuhara, K.; Tamura, M.; Tabayashi, Y.

    2012-12-01

    While efforts to mainstream climate adaptation have only begun in recent years, many developing regions are already taking measures to proof themselves from various natural disasters, including storm surges, flooding, land subsidence, and erosion. In the Asia-Pacific region, one of the most vulnerable in the world, climate resilience is urgently needed due to sea level rise and the increasing frequency and intensity of climate events. Yet, many regions and communities are unprepared due to insufficient awareness of disaster risks. In order to utilize the science of the changing environment more effectively, there is a critical need to understand the social context and perception of those who are affected by climate change. Using the Mekong Delta region in Vietnam as an example, we discuss our current efforts to develop a vulnerability and adaptation index for building climate resilience in the Asia-Pacific Region. A survey of current adaptation efforts in this region will be shown and preliminary findings from our survey to understand the perception of disaster risk in this region will be discussed.

  15. EFFECTIVENESS OF REGIONAL TOURISM INTEGRATION--Case of Quadrangle Economic Cooperation Zone in Great Mekong Region

    Institute of Scientific and Technical Information of China (English)

    XU Hong-gang; BAO Ji-gang; ZHOU Chang-chun

    2006-01-01

    The Quadrangle Economic Cooperation Zone in Great Mekong Region, where the Golden Triangle is located, is composed with the border areas of China,Laos, Thailand and Myanmar. The poorest and inaccessible remote Golden Triangle now faces the opportunity to develop and participate in the global economic system. Not only has the traditional border tourism between two countries in this region been growing rapidly and various tourism products cross the regions also have been developed. The article attempts to explore the multiplier effects of tourism on regional cooperation. These consequences of tourism cooperation take effect through the infrastructure improvement, facilitation of the free movement, improvement of communication and promotion of the alternative economy. The study also points out the unexpected negative consequences to limit its role as a regional cooperative engine due to the lack of consideration of the dual economic and social structure in tourism development. The special attention should be drawn to consider the limited benefits for the marginalized community, the high transaction of the social costs related with the drug tourism and sex tourism. The paper calls for more rigorous cooperative regional plans and policies to the complexity of tourism development in this region.

  16. Luminescence dating of anthropogenically reset canal sediments from Angkor Borei, Mekong Delta, Cambodia

    Science.gov (United States)

    Sanderson, D. C. W.; Bishop, P.; Stark, M. T.; Spencer, J. Q.

    2003-05-01

    This paper presents a case study in the analysis of anthropogenically reset sedimentary materials, through work undertaken to identify and date sediments in an ancient canal in the Mekong Delta, Cambodia. The emergence of rice cultivating communities, utilising canals for both hydraulic management and transport, represents an important stage in the social evolution of southeast Asia. The emergence of complex polities in the region, which may have depended on both international trade and intensified agriculture, led ultimately to the formation of the famous Khmer empires which dominated the region on several occasions through the 1st and 2nd millennia AD. French colonial scholars identified possibly ancient canals in the region that may have played roles in trade, agriculture, or both. This series of ancient canal features near Angkor Borei has been the subject of recent investigations in a collaboration between the Universities of Glasgow and Hawaii. Luminescence profiling measurements were used to identify the canal bed, by exploiting the contrast between a regional substrate of some 50 ka depositional age and more recent archaeological sediments. In this manner it has been possible to identify the sedimentary substrate, undisturbed canal sediments, and redeposited material. Ages have been estimated for substrate and canal infill sediments. The work represents the first convincing demonstration of luminescence dating of one of these important regional features, and indeed the first confirmation of the presumed antiquity of the canal system around Angkor Borei.

  17. 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.

  18. Mosquitoes and their potential predators in rice agroecosystems of the Mekong Delta, southern Vietnam.

    Science.gov (United States)

    Ohba, Shin-Ya; Huynh, T T Trang; Le, Loan Luu; Ngoc, Huu Tran; Hoang, San Le; Takagi, Masahiro

    2011-12-01

    Culex tritaeniorhynchus, Cx. gelidus, and Cx. quinquefasciatus, known vectors of Japanese encephalitis (JE), are distributed in rice agroecosystems in Asian countries. Very few integrated studies on the breeding habitats of rice-field mosquitoes, including JE vectors, have been conducted in Vietnam. We investigated the mosquito fauna and potential predators in 8 rice growing areas in the Mekong Delta region of southern Vietnam, during the wet and dry seasons of 2009. Mosquitoes and their predators were collected from a variety of aquatic habitats (rice fields, ponds, wetlands, shrimp ponds, ditches, canals, and rivers). We collected 936 Culex spp. (354 Cx. tritaeniorhynchus, 240 Cx. vishnui s.l., 189 Cx. fuscocephala, and 42 Cx. gelidus), 33 Uranotaenia, 25 Anopheles, and 9 Mimomyia (4 Mi. chamberlaini) in the dry season. During the rainy season, we collected 1,232 Culex spp. (132 Cx. vishnui s.l., 66 Cx. tritaeniorhynchus, 9 Cx. gelidus, 4 Cx. fuscocephala, and 2 Cx. bitaeniorhynchus), 236 Anopheles spp. (40 An. vagus and 1 An. sinensis), and 7 Uranotaenia (3 Ur. lateralis). Heteroptera such as Micronecta, Veliidae, and Pleidae were abundant and widely distributed in both seasons. Based on a stepwise generalized linear model, the abundance of mosquitoes and their predators in rice fields was high when the rice plant length was short and water depth was shallow. Therefore, the use of insecticides during the earlier stages of rice growth should be avoided in order to preserve the predator populations.

  19. Arsenic release metabolically limited to permanently water-saturated soil in Mekong Delta

    Science.gov (United States)

    Stuckey, Jason W.; Schaefer, Michael V.; Kocar, Benjamin D.; Benner, Shawn G.; Fendorf, Scott

    2016-01-01

    Microbial reduction of arsenic-bearing iron oxides in the deltas of South and Southeast Asia produces widespread arsenic-contaminated groundwater. Organic carbon is abundant both at the surface and within aquifers, but the source of organic carbon used by microbes in the reduction and release of arsenic has been debated, as has the wetland type and sedimentary depth where release occurs. Here we present data from fresh-sediment incubations, in situ model sediment incubations and a controlled field experiment with manipulated wetland hydrology and organic carbon inputs. We find that in the minimally disturbed Mekong Delta, arsenic release is limited to near-surface sediments of permanently saturated wetlands where both organic carbon and arsenic-bearing solids are sufficiently reactive for microbial oxidation of organic carbon and reduction of arsenic-bearing iron oxides. In contrast, within the deeper aquifer or seasonally saturated sediments, reductive dissolution of iron oxides is observed only when either more reactive exogenous forms of iron oxides or organic carbon are added, revealing a potential thermodynamic restriction to microbial metabolism. We conclude that microbial arsenic release is limited by the reactivity of arsenic-bearing iron oxides with respect to native organic carbon, but equally limited by organic carbon reactivity with respect to the native arsenic-bearing iron oxides.

  20. Tidal regime deformation by sea level rise along the coast of the Mekong Delta

    Science.gov (United States)

    Nhan, Nguyen Huu

    2016-12-01

    The future of river deltas is believed to depend mainly on sea level rise (SLR) and on the processes controlling the adaptation of the substrate to human impacts. The deltas are increasingly deprived of riverine sediment by river diversion, dams, dykes and the destruction of wetlands, and they are often sinking due to mining for groundwater, gas and petroleum. The relative sea level rise is causing severe negative impacts in many river deltas worldwide. With continuously rising sea levels, this impact is expected to increase over time. The increased risk of delta flooding caused by tidal deformation associated with SLR in shallow coastal waters has received less attention. In this study, we demonstrate this effect for the case of the Mekong Delta where this study suggests that the maximum tidal water level and the tidal amplitude are increasing while the tidal phase at the coast is decreasing. In addition, the maximum water levels is rising faster than SLR because the tides themselves are modified by SLR. This effect is particularly pronounced for semi-diurnal tides and less so for diurnal tides. Similar effects may prevail for river deltas with extensive shallow coastal waters elsewhere in the world and deserve further investigation.

  1. Getting Road Expansion on the Right Track: A Framework for Smart Infrastructure Planning in the Mekong.

    Science.gov (United States)

    Balmford, Andrew; Chen, Huafang; Phalan, Ben; Wang, Mingcheng; O'Connell, Christine; Tayleur, Cath; Xu, Jianchu

    2016-12-01

    The current unprecedented expansion of infrastructure promises to enhance human wellbeing but risks causing substantial harm to natural ecosystems and the benefits they provide for people. A framework for systematically and proactively identifying the likely benefits and costs of such developments is badly needed. Here, we develop and test at the subregional scale a recently proposed global scheme for comparing the potential gains from new roads for food production with their likely impact on biodiversity and ecosystem services. Working in the Greater Mekong-an exceptionally biodiverse subregion undergoing rapid development-we combined maps of isolation from urban centres, yield gaps, and the current area under 17 crops to estimate where and how far road development could in principle help to increase food production without the need for cropland expansion. We overlaid this information with maps summarising the importance of remaining habitats to terrestrial vertebrates and (as examples of major ecosystem services) to global and local climate regulation. This intersection revealed several largely converted yet relatively low-yielding areas (such as central, eastern, and northeastern Thailand and the Ayeyarwady Delta), where narrowing yield gaps by improving transport links has the potential to substantially increase food production at relatively limited environmental cost. Concentrating new roads and road improvements here while taking strong measures to prevent their spread into areas which are still extensively forested (such as northern Laos, western Yunnan, and southwestern Cambodia) could thus enhance rural livelihoods and regional food production while helping safeguard vital ecosystem services and globally significant biological diversity.

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

    Science.gov (United States)

    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.

  3. Bottom sediments affect Sonneratia mangrove forests in the prograding Mekong delta, Vietnam

    Science.gov (United States)

    Nardin, William; Woodcock, Curtis E.; Fagherazzi, Sergio

    2016-08-01

    Mangrove forests exert a strong influence on tropical deltas by trapping sediments discharged by rivers and by stabilizing the substrate with roots. Understanding the dynamics of sediments and morphology in and around mangrove forests is critical in order to assess the resilience of coastlines in a period of accelerated sea level rise. In this research, sediment samples, mangrove forest characteristics, and remote sensing data are used to investigate the relationship between mangroves and sediment substrate in the Mekong Delta, Vietnam. Our data show a significant correlation between percent of sand in bottom sediments and density of Sonneratia caseolaris forest. We ascribe this result to higher sediment disturbance in muddy areas that prevents seedling establishment. This correlation potentially allows the determination of substrate characteristics from vegetation attributes detected by remote sensing, despite the impenetrability of the forest canopy. The results presented herein suggest that a supply of sand from the river and hydrodynamic processes moving the sand ashore control the density of the Sonneratia mangrove forests at this location, promoting tidal flat colonization and canopy expansion.

  4. 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.

  5. Flood Mapping in the Lower Mekong River Basin Using Daily MODIS Observations

    Science.gov (United States)

    Fayne, Jessica V.; Bolten, John D.; Doyle, Colin S.; Fuhrmann, Sven; Rice, Matthew T.; Houser, Paul R.; Lakshmi, Venkat

    2017-01-01

    In flat homogenous terrain such as in Cambodia and Vietnam, the monsoon season brings significant and consistent flooding between May and November. To monitor flooding in the Lower Mekong region, the near real-time NASA Flood Extent Product (NASA-FEP) was developed using seasonal normalized difference vegetation index (NDVI) differences from the 250 m resolution Moderate Resolution Imaging Spectroradiometer (MODIS) sensor compared to daily observations. The use of a percentage change interval classification relating to various stages of flooding reduces might be confusing to viewers or potential users, and therefore reducing the product usage. To increase the product usability through simplification, the classification intervals were compared with other commonly used change detection schemes to identify the change classification scheme that best delineates flooded areas. The percentage change method used in the NASA-FEP proved to be helpful in delineating flood boundaries compared to other change detection methods. The results of the accuracy assessments indicate that the -75% NDVI change interval can be reclassified to a descriptive 'flood' classification. A binary system was used to simplify the interpretation of the NASA-FEP by removing extraneous information from lower interval change classes.

  6. Gender relations and sexual communication among female students in the Mekong River Delta of Vietnam.

    Science.gov (United States)

    Bui, Thanh Cong; Diamond, Pamela M; Markham, Christine; Ross, Michael W; Nguyen-Le, Thanh-An; Tran, Ly Hai Thi

    2010-08-01

    Young women's ability to pursue a safer-sex life in line with their wishes is crucial to their sexual health. Although some previous observations have suggested that young women's lack of ability to negotiate safer sex is due to gender power imbalances in the culture of Vietnam, studies that have tested this hypothesis explicitly and quantitatively are few and far between. The present study aimed to test the association between perceived gender relations and perceived self-efficacy in communicating sexual matters among undergraduate female students in the Mekong River Delta of Vietnam. The analysis involved secondary data from 260 subjects from a larger survey regarding gender equity. Structural equation modeling was used to examine the study's hypothesis. Results showed that adherence to traditional gender roles and norms was significantly associated with female students' reduced self-efficacy to communicate on safer-sex matters, such as refusing unwanted sex or requesting condom use. This association remained invariant in the cross-validation process between partnered and unpartnered groups. Programmes that aim to promote safer-sex negotiation and practices for this population may need to address the influence of gender relations and power.

  7. Refuge in Belen Valley

    OpenAIRE

    Arias-Caballero, Diego Andres

    2013-01-01

    A story about love and desire to imagine architecture in a peruvian landscape. On one hand, 'Refuge in Belen Valley' is a thesis about discovering the ideal conditions that architecture should meet in a landscape, conditions that approach the idea of an offering of man rather than a conditioning for man. On the other, it is a thesis about thinking architecture as a composition derived out of material properties, emotional intentions, inhabiting possibilities and counterpoint, the arrangement ...

  8. Building China's Silicon Valley

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Ellis Rahhal and Andrew Schorr sit across from each other in the minimalist office of their tech startup,all clean lines and white linoleum floors.A pair of toothbrushes hint at many a late night hunched over their computers.Outside the window,the sun is slowly setting behind jagged mountains.The scene is classic Silicon Valley.But Rahhal and Schorr aren't in California.They're in suburban Beijing.

  9. Mississippi Alluvial Valley

    Science.gov (United States)

    Reinecke, K.J.; Kaminski, R.M.; Moorhead, D.J.; Hodges, J.D.; Nasser, J.R.; Smith, L.M.; Pederson, R.L.; Kaminski, R.M.

    1989-01-01

    Available data are summarized according to the following major topics: (1) characteristics of the Mississippi Alluvial Valley (MAV); (2) waterfowl populations associated with the MAV; (3) habitat requirements of migrating and wintering waterfowl in the MAV; (4) current habitat management practices in the MAV, including croplands, moist-soil impoundments, and forested wetlands; (5) status and classification of winter habitat in the MAV; and (6) research and management information needs.

  10. Green valley galaxies

    Directory of Open Access Journals (Sweden)

    Salim S.

    2014-01-01

    Full Text Available The “green valley” is a wide region separating the blue and the red peaks in the ultraviolet-optical color magnitude diagram, first revealed using GALEX UV photometry. The term was coined by Christopher Martin (Caltech, in 2005. Green valley highlights the discriminating power of UV to very low relative levels of ongoing star formation, to which the optical colors, including u−r, are insensitive. It corresponds to massive galaxies below the star-forming, “main” sequence, and therefore represents a critical tool for the study of the quenching of star formation and its possible resurgence in otherwise quiescent galaxies. This article reviews the results pertaining to (predominantly disk morphology, structure, environment, dust content and gas properties of green valley galaxies in the local universe. Their relationship to AGN is also discussed. Attention is given to biases emerging from defining the “green valley” using optical colors. We review various evolutionary scenarios and we present evidence for a new one, the quasi-static view of the green valley, in which the majority (but not all of galaxies currently in the green valley were only partially quenched in the distant past and now participate in a slow cosmic decline of star formation, which also drives down the activity on the main sequence, presumably as a result of the dwindling accretion/cooling onto galaxy disks. This emerging synthetic picture is based on the findings from Fang et al. (2012, Salim et al. (2012 and Martin et al. (2007, as well as other results.

  11. 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.

  12. Off-farm employment and income poverty in favourable agro-climatic areas of Tanzania

    DEFF Research Database (Denmark)

    Msinde, John Victor; Urassa, Justin K.; Nathan, Iben

    2016-01-01

    in the first quarter of 2014 in five villages of Kilombero Valley, Tanzania using a structured questionnaire. Income poverty was analysed using the Foster-Greer-Thorbecke (FGT) poverty index and two stage least square (2SLS) regression. Households with off-farm employment income were found to be less poor......Income poverty in Tanzania as elsewhere in developing countries is predominantly a rural phenomenon and affects largely households relying on subsistence farming. This is despite the fact that poverty reduction strategies have devoted increasing attention on the role farm employment in enhancing...... household income. This paper argues that, off-farm employment may have potential to contribute to reduction of rural households’ income poverty. Hence the main objective of the paper is set to examine effects of off-farm employment on income poverty. Data was collected from a random sample of 309 households...

  13. Certified safe farm: identifying and removing hazards on the farm.

    Science.gov (United States)

    Rautiainen, R H; Grafft, L J; Kline, A K; Madsen, M D; Lange, J L; Donham, K J

    2010-04-01

    This article describes the development of the Certified Safe Farm (CSF) on-farm safety review tools, characterizes the safety improvements among participating farms during the study period, and evaluates differences in background variables between low and high scoring farms. Average farm review scores on 185 study farms improved from 82 to 96 during the five-year study (0-100 scale, 85 required for CSF certification). A total of 1292 safety improvements were reported at an estimated cost of $650 per farm. A wide range of improvements were made, including adding 9 rollover protective structures (ROPS), 59 power take-off (PTO) master shields, and 207 slow-moving vehicle (SMV) emblems; improving lighting on 72 machines: placing 171 warning decals on machinery; shielding 77 moving parts; locking up 17 chemical storage areas, adding 83 lockout/tagout improvements; and making general housekeeping upgrades in 62 farm buildings. The local, trained farm reviewers and the CSF review process overall were well received by participating farmers. In addition to our earlier findings where higher farm review scores were associated with lower self-reported health outcome costs, we found that those with higher farm work hours, younger age, pork production in confinement, beef production, poultry production, and reported exposure to agrichemicals had higher farm review scores than those who did not have these characteristics. Overall, the farm review process functioned as expected. encouraging physical improvements in the farm environment, and contributing to the multi-faceted CSF intervention program.

  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. Extending the Hydraulic Paradigm: Reunification, State Consolidation, and Water Control in the Vietnamese Mekong Delta after 1975

    Directory of Open Access Journals (Sweden)

    Simon Benedikter

    2014-12-01

    Full Text Available As vividly depicted by James Scott (1998, environmental transformation and the utilization of natural resources for development have, in modern human history, often been driven by the high-modernist world views of (authoritarian governments. In this context, environmental historians ascribe a powerful role to (hydraulic engineers as agents of ecological and social transformation. With their epistemic power arising from their association with rational-modern science and technology development, engineers emerged as protagonists of large-scale landscape engineering and water control ventures coordinated by the nation state in the light of modernization. Against this historical background, this paper traces the post-reunification hydraulic mission in the Mekong Delta (1975–90 and highlights the strategic role that state-led water control efforts guided by hydraulic engineers have played in economic recovery, nation building, and state consolidation under socialism. It is argued that water resources development in the Mekong Delta is deeply embedded in the country’s historical trajectory, which is framed by national division, the struggle for independence, and the subsequent reunification under the Vietnam Communist Party’s leadership. The socialist hydraulic bureaucracy, which arose in the 1950s in North Vietnam, capitalized on the opportune moment of reunification of North and South and systematically expanded its control over the southern waterscape. In this context, the paper presents a historical perspective on how water development strategies and institutional arrangements evolved when North Vietnamese engineers took over water resources management in the Mekong Delta. These past developments still have far-reaching implications for present-day water management dynamics in Vietnam’s largest river estuary.

  16. River Network Uncertainty and Coastal Morphodynamics in the Mekong Delta: Model Validation and Sensitivity to Fluvial Fluxes

    Science.gov (United States)

    Tessler, Z. D.; Vorosmarty, C. J.; Cohen, S.; Tang, H.

    2014-12-01

    A loose-coupling of a basin-scale hydrological and sediment flux model with acoastal ocean hydrodynamics model is used to assess the importance ofuncertainties in river mouth locations and fluxes on coastal geomorphology ofthe Mekong river delta. At the land-ocean interface, river deltas mediate theflux of water, sediment, and nutrients from the basin watershed, though thecomplex delta river network, and into the coastal ocean. In the Mekong riverdelta, irrigation networks and surface water storage for rice cultivationredistribute, in space and time, water and sediment fluxes along the coastline.Distribution of fluxes through the delta is important for accurate assessment ofdelta land aggregation, coastline migration, and coastal ocean biogeochemistry.Using a basin-scale hydrological model, WBMsed, interfaced with a coastalhydrodynamics/wave/sediment model, COAWST, we investigate freshwater andsediment plumes and morphological changes to the subaqueous delta front. Thereis considerable uncertainty regarding how the delta spatially filters water andsediment fluxes as they transit through the river and irrigation network. Byadjusting the placement and relative distribution of WBMsed discharge along thecoast, we estimate the resulting bounds on sediment plume structure, timing, andmorphological deposition patterns. The coastal ocean model is validated bycomparing simulated plume structure and seasonality to MERIS and MODIS derivedestimates of surface turbidity. We find good agreement with regards to plumeextent and timing, with plumes weakest in the early spring, extending stronglyto the west in the fall, and toward the east in winter. Uncertainty regardingriver outflow distribution along the coastline leads to substantial uncertaintyin rates of morphological change, particularly away from the main Mekong Riverdistributary channels.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. 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

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

    Directory of Open Access Journals (Sweden)

    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. Balancing Energy, Food Security, and Critical Ecosystems: Dam Siting, Design and Operations in the Mekong River Basin

    Science.gov (United States)

    Wild, T. B.; Reed, P. M.; Loucks, D.

    2016-12-01

    The Mekong River basin in Southeast Asia is one of several river basins with exceptionally high biodiversity value where intensive hydropower dam development is anticipated. In the Mekong basin, over 100 dams are planned to be constructed in the next 20-30 years. As planned, these dams will alter the river's natural water, sediment and nutrient flows, and will fragment fish migration pathways. In doing so, they will degrade one of the world's most productive freshwater fish habitats, upon which some 60 million people depend for food and income security. For those dams that have not yet been constructed, there still exist opportunities to modify their siting, design and operation (SDO) to achieve a more balanced set of tradeoffs among hydropower production, sediment/nutrient passage and adult fish/larvae passage. We present a successful case study wherein we explored such alternative SDO opportunities in partnership with the Government of Cambodia for Sambor Dam, planned to be built on the main stem of the Mekong. Sambor would be one of the world's longest dams, spanning 18 km across the river just upstream of (1) Tonle Sap Lake, which supplies 70% of Cambodians' protein, and (2) the Mekong Delta in Vietnam, responsible for 50% of Vietnam's rice production. We will describe key dam siting and design modifications required to mitigate ecological impacts. We will then focus on the most promising alternative dam siting/design concept, exploring the reservoir operations space to demonstrate that a complex set of tradeoffs exist among a diverse set of energy and ecosystem objectives. Results indicate that even for a hydrologically small reservoir, a wide array of potential reservoir operating policies exist that have vastly different food-energy implications. While some policies would significantly mitigate ecological impacts, many policies exist that would pose a severe threat to the sustainability of the fishery. Failure to sample the reservoir operations space at

  1. Optical manipulation of valley pseudospin

    Science.gov (United States)

    Ye, Ziliang; Sun, Dezheng; Heinz, Tony F.

    2017-01-01

    The coherent manipulation of spin and pseudospin underlies existing and emerging quantum technologies, including quantum communication and quantum computation. Valley polarization, associated with the occupancy of degenerate, but quantum mechanically distinct valleys in momentum space, closely resembles spin polarization and has been proposed as a pseudospin carrier for the future quantum electronics. Valley exciton polarization has been created in the transition metal dichalcogenide monolayers using excitation by circularly polarized light and has been detected both optically and electrically. In addition, the existence of coherence in the valley pseudospin has been identified experimentally. The manipulation of such valley coherence has, however, remained out of reach. Here we demonstrate all-optical control of the valley coherence by means of the pseudomagnetic field associated with the optical Stark effect. Using below-bandgap circularly polarized light, we rotate the valley exciton pseudospin in monolayer WSe2 on the femtosecond timescale. Both the direction and speed of the rotation can be manipulated optically by tuning the dynamic phase of excitons in opposite valleys. This study unveils the possibility of generation, manipulation, and detection of the valley pseudospin by coupling to photons.

  2. Session: Long Valley Exploratory Well

    Energy Technology Data Exchange (ETDEWEB)

    Tennyson, George P. Jr.; Finger, John T.; Eichelberger, John C.; Hickox, Charles E.

    1992-01-01

    This session at the Geothermal Energy Program Review X: Geothermal Energy and the Utility Market consisted of four presentations: ''Long Valley Exploratory Well - Summary'' by George P. Tennyson, Jr.; ''The Long Valley Well - Phase II Operations'' by John T. Finger; ''Geologic results from the Long Valley Exploratory Well'' by John C. Eichelberger; and ''A Model for Large-Scale Thermal Convection in the Long Valley Geothermal Region'' by Charles E. Hickox.

  3. Social Networks in Silicon Valley

    Institute of Scientific and Technical Information of China (English)

    Joseph Leu

    2006-01-01

    @@ Social network is a dominant, distinguishing characteristic of Silicon Valley. Because innovation entails coping with a high degree of uncertainty,such innovation is particularly dependent on networks.

  4. Segetal flora of the Middle Vistula River Valley

    Directory of Open Access Journals (Sweden)

    Maria Ługowska

    2014-12-01

    Full Text Available The objective of the study was to describe the segetal flora of the Middle Vistula River Valley. A total of 367 species were recorded in spring and winter cereals, tuber crops, and stubble fields. Such floristic abundance may be due to the fact that the study area is located in the proximity of a river where semi-natural communities interact directly with communities inhabiting cultivated fields and that fields are fragmented and characterised by different habitats. There were more apophytes (62% than anthropophytes (38% in the flora studied. Meadow apophytes were the dominant native species (35% and archeophytes were the dominant anthropophytes (69%. The analysis of the life spectrum revealed that there were more therophytes (50% than hemicryptophytes (39%. What is more, non-perennial species constituted 56% and perennials 44% of the segetal flora established in the Middle Vistula River Valley. The large proportion of archeophytes (26% may indicate that traditional farming predominated in the study area.

  5. 澜沧江-湄公河重金属污染评价及大坝影响%Pollution assessment of heavy metals along the Mekong River and dam effects

    Institute of Scientific and Technical Information of China (English)

    FU Kaidao; SU Bin; HE Daming; LU Xixi; SONG Jingyi; HUANG Jiangcheng

    2012-01-01

    @@%The resource development and changes of hydrological regime,sediment and water quality in the Mekong River basin have attracted great attentions.This research aimed to enhance the study on transboundary pollution of heavy metals in this international river.In this study,eight sampling sites were selected to collect the bed sand samples along the mainstream of the Mekong River.In addition,the contents of 5 heavy metal elements and their spatial variability along the mainstream of the river were analyzed.The geoaccumulation index (Igeo) and potential ecological risk analysis were employed to assess heavy metal pollution status in the mainstream of the Mekong River.The results show that the average content of the heavy metal elements Zn is 91.43 mg/kg,Pb is 41.85 mg/kg,and As is 21.84 mg/kg in the bed sands of the Upper Mekong River,which are higher than those (Zn 68.17 mg/kg,Pb 28.22 mg/kg,As 14.97 mg/kg) in the Lower Mekong.The average content of Cr in the Lower Mekong is 418.86 mg/kg,higher than that in the Upper Mekong (42.19 mg/kg).Luang Prabang has a very high Cr concentration with 762.93 mg/kg and Pakse with 422.90 mg/kg.The concentration of Cu in all of the 8 sampling sites is similar,except for in Jiajiu with 11.70 mg/kg and Jiebei with 7.00 mg/kg.The results of the geoaccumulation index reveal that contaminations caused by Zn and Pb while Pb and As are more than those by Zn in Upper Mekong.Cr is the primary pollutant in the Lower Mekong,especially at Luang Prabang and Pakse.Slight pollution with As also occurs in Pakse.The potential ecological risk index indicates that the potential ecological risk of heavy metals in the mainstream of the Mekong River is low.We argue that the pollution of water quality and contamination of heavy metals in bed sediment caused by mining of mineral resources or geochemical background values in the Mekong is not transmitted from the Upper to the Lower Mekong because of the reservoir sedimentation and dilution along the river.

  6. Childhood asthma, air quality, and social suffering among Mexican Americans in California's San Joaquin Valley: "Nobody talks to us here".

    Science.gov (United States)

    Schwartz, Norah Anita; Pepper, David

    2009-10-01

    Nearly one in five Mexican American children residing in California's San Joaquin Valley (the Valley) in 2007 had an asthma attack at some point in their life. Numerous epidemiological studies have suggested that compared with other ethnic groups and Latino subgroups residing in the United States, Mexican origin children have the lowest rates of pediatric asthma. Ethnographic research conducted in central California, however, suggests otherwise. Known for its agricultural produce, extreme poverty, and poor air quality, the Valley is a magnet for the Mexican immigrant farm worker population. We conducted an exploratory ethnographic study to examine health disparities, social suffering, and childhood asthma in the Valley. Many Valley residents believe that their children's health concerns are being ignored. Open-ended interviews uncovered a largely rural community suffering not only from the effects of childhood asthma but the inability to have their experiences taken seriously.

  7. Synthetic River Valleys

    Science.gov (United States)

    Brown, R.; Pasternack, G. B.

    2011-12-01

    The description of fluvial form has evolved from anecdotal descriptions to artistic renderings to 2D plots of cross section or longitudinal profiles and more recently 3D digital models. Synthetic river valleys, artificial 3D topographic models of river topography, have a plethora of potential applications in fluvial geomorphology, and the earth sciences in general, as well as in computer science and ecology. Synthetic river channels have existed implicitly since approximately the 1970s and can be simulated from a variety of approaches spanning the artistic and numerical. An objective method of synthesizing 3D stream topography based on reach scale attributes would be valuable for sizing 3D flumes in the physical and numerical realms, as initial input topography for morphodynamic models, stream restoration design, historical reconstruction, and mechanistic testing of interactions of channel geometric elements. Quite simply - simulation of synthetic channel geometry of prescribed conditions can allow systematic evaluation of the dominant relationships between river flow and geometry. A new model, the control curve method, is presented that uses hierarchically scaled parametric curves in over-lapping 2D planes to create synthetic river valleys. The approach is able to simulate 3D stream geometry from paired 2D descriptions and can allow experimental insight into form-process relationships in addition to visualizing past measurements of channel form that are limited to two dimension descriptions. Results are presented that illustrate the models ability to simulate fluvial topography representative of real world rivers as well as how channel geometric elements can be adjusted. The testing of synthetic river valleys would open up a wealth of knowledge as to why some 3D attributes of river channels are more prevalent than others as well as bridging the gap between the 2D descriptions that have dominated fluvial geomorphology the past century and modern, more complete, 3D

  8. Long Island Solar Farm

    Energy Technology Data Exchange (ETDEWEB)

    Anders, R.

    2013-05-01

    The Long Island Solar Farm (LISF) is a remarkable success story, whereby very different interest groups found a way to capitalize on unusual circumstances to develop a mutually beneficial source of renewable energy. The uniqueness of the circumstances that were necessary to develop the Long Island Solar Farm make it very difficult to replicate. The project is, however, an unparalleled resource for solar energy research, which will greatly inform large-scale PV solar development in the East. Lastly, the LISF is a superb model for the process by which the project developed and the innovation and leadership shown by the different players.

  9. Wind Farm Recommendation Report

    Energy Technology Data Exchange (ETDEWEB)

    John Reisenauer

    2011-05-01

    On April 21, 2011, an Idaho National Laboratory (INL) Land Use Committee meeting was convened to develop a wind farm recommendation for the Executive Council and a list of proposed actions for proceeding with the recommendation. In terms of land use, the INL Land Use Committee unanimously agrees that Site 6 is the preferred location of the alternatives presented for an INL wind farm. However, further studies and resolution to questions raised (stated in this report) by the INL Land Use Committee are needed for the preferred location. Studies include, but are not limited to, wind viability (6 months), bats (2 years), and the visual impact of the wind farm. In addition, cultural resource surveys and consultation (1 month) and the National Environmental Policy Act process (9 to 12 months) need to be completed. Furthermore, there is no documented evidence of developers expressing interest in constructing a small wind farm on INL, nor a specific list of expectations or concessions for which a developer might expect INL to cover the cost. To date, INL assumes the National Environmental Policy Act activities will be paid for by the Department of Energy and INL (the environmental assessment has only received partial funding). However, other concessions also may be expected by developers such as roads, fencing, power line installation, tie-ins to substations, annual maintenance, snow removal, access control, down-time, and remediation. These types of concessions have not been documented, as a request, from a developer and INL has not identified the short and long-term cost liabilities for such concessions should a developer expect INL to cover these costs. INL has not identified a go-no-go funding level or the priority this Wind Farm Project might have with respect to other nuclear-related projects, should the wind farm remain an unfunded mandate. The Land Use Committee recommends Legal be consulted to determine what, if any, liabilities exist with the Wind Farm Project and

  10. Technologies in organic farming

    DEFF Research Database (Denmark)

    Lassen, Jesper

    2015-01-01

    (pollution) and consequences for human health. Broader ideas about ecosystems and the recycling of nutrients between the agricultural sector and the urban population are notably absent. On the basis of these findings the paper concludes by discussing the relationship between the consumers’ values that guide......In organic farming a dilemma is posed by the heavy reliance on nutrients from conventional livestock farming. For Danish organic plant producers the influx of conventional nutrients accounts for up to 70% of their nutrients. Facing this problem, Danish organic farmers’ organizations have decided...

  11. Silicon Valley Lifestyle

    Institute of Scientific and Technical Information of China (English)

    Joseph Leu

    2005-01-01

    @@ As we embrace the rapid developments of the new media age,competitiveness in the field of internet and computer technology is an increasingly crucial factor in stimulating new business,jobs and new industry in the region.Accelerating advancements in new media,internet,software and computer technologies offer new commercial opportunities and sources of economic revenue. Silicon Valley has been a model of the new age since its existence.While the dream place not only has a unique business model,but also has a very special lifestyle.

  12. Water turbidity mapping using Landsat-8 data in Mekong and Bassac Rivers, Vietnam

    Science.gov (United States)

    Lau, Va-Khin; Chen, Chi-Farn; Nguyen, Thanh-Son; Lam, Dao-Nguyen; Chen, Cheng-Ru

    2016-04-01

    Turbidity is the cloudiness or haziness measured by the intensity of light scattered through a water sample and turbidity is often used as an indicator of water quality. Traditional studies of water turbidity are often implemented through costly and time-consuming field surveys, and water samples are analyzed in the laboratory. This method can be applied for a small region. However, the method often creates limitation due to the time bias of data collection, interpolation error, and cost when applied to a large region. In recent year, remote sensing technologies have proved the capacity of mapping turbidity or suspended solids by various data sources, including aerial photography, high resolution images (e.g., Spot, Formosat) and medium resolution images (e.g., Landsat), and low resolution images (e.g., MODIS, MERIS, and VIIR). The main of this study is to investigate the applicability of Landsat data for water turbidity mapping in Mekong and Bassac Rivers, Vietnam. The length of these two main rivers is approximately 210 km with the width ranging from 500 m to 5 km. Aerial photos and high resolution images (e.g., IKONOS, QuickView) are good candidates for this water turbidity monitoring purpose. However, it is costly. Low resolution images such as MODIS are relatively coarse, given the width of rivers in some areas smaller than 500 m. The Landsat 8 satellite launched in 2013 provides the multispectral data with seven bands and 30 m resolution, which are deemed suitable for water turbidity monitoring in the study region, and thus used in this study. The data were processed by first converting the digital number of each pixel to radiance. The atmospheric correction using FLAASH model was accordingly applied to generate surface reflectance data. We used the Bayesian model average (BMA) to investigate the relationship between Landsat spectral bands and field survey data, which were collected from 63 sites of 21 transects across the two rivers on 24 January 2015

  13. 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.

  14. Linking ecology to hydrology and geomorphology using river reach classification for the Greater Mekong Region

    Science.gov (United States)

    Ouelette Dallaire, Camille; Lehner, Bernhard

    2016-04-01

    Large-scale development projects, such as hydropower dams, in the Greater Mekong Region (GMR) are putting high pressure on freshwater resources. Environmental impact assessments are needed in the region to understand the possible impacts of these projects. These assessments often require biodiversity data that can be costly to acquire both in terms of time and money. It is often assumed that river or ecosystem classes, based on geo-physical characteristics, can be used as biodiversity proxies in large scale assessments to account for a lack of biodiversity data. However, there has been little research to compare the spatial distribution of river classes and fish species. It is unclear how well river classes are able to represent the distribution of fish and, more generally, biodiversity. To address this question, a set of two classifications were compared to a newly available dataset of fish species distribution in the GMR (Allen et al., 2012). The classifications were derived from two different methods to test which could potentially better represent fish assemblages. The first classification is derived using regional expert knowledge and the second using K-mean analysis. Both are using the same geophysical datasets. The two datasets were used in a Redundancy Analysis (RDA) to calculate which proportion of the variability in the fish species data can be explained by the river classes. The RDA resulted in R2 of 0.44 for the supervised classification and 0.41for the statistical classification, showing a moderate correlation between the datasets. Based on these results, using river classes as biodiversity proxy is deemed reasonable. However, some of the variability in the distribution of fish species cannot be related simply to geophysical factors. River classes may capture different elements such as unique habitats and associated, possibly unknown, endemic species that indices based only on biological data do not. Hence, river classes can be a good alternative and

  15. 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.

  16. The Kriging Method for Combining Multi-Mission Altimetry over the Mekong River

    Science.gov (United States)

    Boergens, Eva; Buhl, Sven; Dettmering, Denise; Schwatke, Christian; Seitz, Florian

    2016-08-01

    In recent years, water level variations of inland water bodies such as lakes, reservoirs, and rivers measured by satellite altimetry got well established. Most inland water level time series are only assembled from measurements of one pass of one single satellite mission. Only a few multi-mission approaches combine different missions and passes over lakes and reservoirs in order to increase the accuracy and temporal resolution of the time series. This is possible because the lake surface can be considered to be constant everywhere at a given time. However, it is not possible so far to combine different altimeter missions and passes over rivers.We developed a new methodology to combine altimetry data from different missions in a statistical robust way along the river. The methodology is based on kriging which is an interpolation method originating from geostatistics. We expanded the concept to spatio-temporal kriging along the river. The interpolation is a weighted average of available measurements based on empirical correlations not only in the spatial domain but in the temporal domain as well. The higher the correlation, the more weight a measurement obtains in the average. With this approach we are able to combine data not only along the river at a given time or a given location but also data at another location at another time. We developed a statistical model to describe the dependencies between different measurement locations; a prerequisite for the kriging algorithm.We employed the kriging method on altimeter measurements of the Mekong River in South-east Asia. Data of the Envisat, Envisat EM, Jason-2, and SARAL/AltiKa mission were incorperated. With this we are able to achieve a higher temporal resolution time series at any given location. The resulting estimated time series are compared to in-situ data from gauging stations along the river and show a high agreement with these.

  17. Observed river discharge changes due to hydropower operations in the Upper Mekong Basin

    Science.gov (United States)

    Räsänen, Timo A.; Someth, Paradis; Lauri, Hannu; Koponen, Jorma; Sarkkula, Juha; Kummu, Matti

    2017-02-01

    The Upper Mekong Basin is undergoing extensive hydropower development and its largest dams have recently become operational. Hydropower is built to improve the regional energy supply, but at the same time, it has considerable transboundary impacts on downstream discharge regime and further on aquatic ecosystems, riparian livelihoods and food security. Despite the transboundary significance of the impacts, there is no public information on the hydropower operations or on the already observed downstream discharge impacts since the completion of the largest dams. Therefore, in this study we assess the discharge changes using observed river discharge data and a distributed hydrological model over the period of 1960-2014. Our findings indicate that the hydropower operations have considerably modified the river discharges since 2011 and the largest changes were observed in 2014. According to observed and simulated discharges, the most notable changes occurred in northern Thailand (Chiang Saen) in March-May 2014 when the discharge increased by 121-187% and in July-August 2014 when the discharge decreased by 32-46% compared to average discharges. The respective changes in Cambodia (Kratie) were 41-74% increase in March-May 2014 and 0-6% decrease in July-August 2014 discharges. The earlier model-based predictions of the discharge changes are well in line with the observed changes, although observed changes are partly larger. The discharge impacts are expected to vary from year to year depending on hydropower operations. Altogether, the results highlight the need for strong transboundary cooperation for managing the downstream impacts.

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

    Science.gov (United States)

    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.

  19. 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

  20. Current status of arsenic exposure and social implication in the Mekong River basin of Cambodia.

    Science.gov (United States)

    Phan, Kongkea; Kim, Kyoung-Woong; Huoy, Laingshun; Phan, Samrach; Se, Soknim; Capon, Anthony Guy; Hashim, Jamal Hisham

    2016-06-01

    To evaluate the current status of arsenic exposure in the Mekong River basin of Cambodia, field interview along with urine sample collection was conducted in the arsenic-affected area of Kandal Province, Cambodia. Urine samples were analyzed for total arsenic concentrations by inductively coupled plasma mass spectrometry. As a result, arsenicosis patients (n = 127) had As in urine (UAs) ranging from 3.76 to 373 µg L(-1) (mean = 78.7 ± 69.8 µg L(-1); median = 60.2 µg L(-1)). Asymptomatic villagers (n = 108) had UAs ranging from 5.93 to 312 µg L(-1) (mean = 73.0 ± 52.2 µg L(-1); median = 60.5 µg L(-1)). About 24.7 % of all participants had UAs greater than 100 µg L(-1) which indicated a recent arsenic exposure. A survey found that females and adults were more likely to be diagnosed with skin sign of arsenicosis than males and children, respectively. Education level, age, gender, groundwater drinking period, residence time in the village and amount of water drunk per day may influence the incidence of skin signs of arsenicosis. This study suggests that residents in Kandal study area are currently at risk of arsenic although some mitigation has been implemented. More commitment should be made to address this public health concern in rural Cambodia.

  1. 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

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

    NARCIS (Netherlands)

    Le Quang Minh,

    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 acid sulphate

  3. Impact of climate change on sediment yield in the Mekong River basin: a case study of the Nam Ou basin, Lao PDR

    NARCIS (Netherlands)

    Shrestha, B.; Babel, M.S.; Maskey, S.; Van Griensven, A.; Uhlenbrook, S.; Green, A.; Akkharath, I.

    2013-01-01

    This paper evaluates the impact of climate change on sediment yield in the Nam Ou basin located in northern Laos. Future climate (temperature and precipitation) from four general circulation models (GCMs) that are found to perform well in the Mekong region and a regional circulation model (PRECIS) a

  4. Perspective: Towards environmentally acceptable criteria for downstream fish passage through mini hydro and irrigation infrastructure in the Lower Mekong River Basin

    Energy Technology Data Exchange (ETDEWEB)

    Baumgartner, Lee J.; Daniel Deng, Z.; Thorncraft, Garry; Boys, Craig A.; Brown, Richard S.; Singhanouvong, Douangkham; Phonekhampeng, Oudom

    2014-01-01

    Tropical rivers have high annual discharges optimal for hydropower and irrigation development. The Mekong River is one of the largest tropical river systems, supporting a unique mega-diverse fish community. Fish are an important commodity in the Mekong, contributing a large proportion of calcium, protein, and essential nutrients to the diet of the local people and providing a critical source of income for rural households. Many of these fish migrate not only upstream and downstream within main-channel habitats but also laterally into highly productive floodplain habitat to both feed and spawn. Most work to date has focused on providing for upstream fish passage, but downstream movement is an equally important process to protect. Expansion of hydropower and irrigation weirs can disrupt downstream migrations and it is important to ensure that passage through regulators or mini hydro systems is not harmful or fatal. Many new infrastructure projects (<6 m head) are proposed for the thousands of tributary streams throughout the Lower Mekong Basin and it is important that designs incorporate the best available science to protect downstream migrants. Recent advances in technology have provided new techniques which could be applied to Mekong fish species to obtain design criteria that can facilitate safe downstream passage. Obtaining and applying this knowledge to new infrastructure projects is essential in order to produce outcomes that are more favorable to local ecosystems and fisheries.

  5. Roads and Floods: Best Practice Guidelines for the Integrated Planning and Design of Economically Sound and Environmentally Friendly Roads in the Mekong Floodplains of Cambodia and Viet Nam

    NARCIS (Netherlands)

    Douven, W.J.A.M.; Goichot, M.; Verheij, H.J.

    2009-01-01

    This document presents a set of Best Practice Guidelines for road development and rehabilitation in the Mekong floodplains of Cambodia and Viet Nam. The guidelines are developed under the ‘Roads and Floods’ project1. The guidelines are based on the review of local practice, international experience,

  6. 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.

  7. 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

  8. 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 drainage is the

  9. Urban Farm Business Plan Handbook

    Science.gov (United States)

    The Urban Farm Business Plan Handbook (this document) provides guidance for developing a business plan for the startup and operation of an urban farm. It focuses on food and non-food related cultivated agriculture.

  10. Farm animal welfare

    DEFF Research Database (Denmark)

    Sandøe, Peter; Christiansen, Stine Billeschou; Appleby, M. C.

    2003-01-01

    An experimental survey was undertaken to explore the links between the characteristics of a moral issue, the degree of moral intensity/moral imperative associated with the issue (Jones, 1991), and people’s stated willingness to pay (wtp) for policy to address the issue. Two farm animal welfare...

  11. NORCOWE Reference Wind Farm

    DEFF Research Database (Denmark)

    Bak, Thomas; Graham, Angus

    2015-01-01

    Offshore wind farms are complex systems, influenced by both the environment (e.g. wind, waves, current and seabed) and the design characteristics of the equipment available for installation (e.g. turbine type, foundations, cabling and distance to shore). These aspects govern the capital and opera...

  12. FARM ANIMAL WELFARE ECONOMICS

    Directory of Open Access Journals (Sweden)

    L.T. CZISZTER

    2013-07-01

    Full Text Available This paper reviews the literature regarding the economics of the farm animal welfare. The following issues are addressed: productions costs and savings of the animal welfare regulations, benefits of improved animal welfare, and consumers’ willingness to pay for animal-friendly products.

  13. Farm animal welfare

    DEFF Research Database (Denmark)

    Sandøe, Peter; Christiansen, Stine Billeschou; Appleby, M. C.

    2003-01-01

    An experimental survey was undertaken to explore the links between the characteristics of a moral issue, the degree of moral intensity/moral imperative associated with the issue (Jones, 1991), and people’s stated willingness to pay (wtp) for policy to address the issue. Two farm animal welfare...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Population pressure and farm fragmentation:

    African Journals Online (AJOL)

    user

    small but farms are further fragmented into diminutive size fields due to ... terms of household characteristics; land use and performance indicators; technology adoption .... 'best' unit of measurement of farm size, and size of enterprises within farms will ..... less common, accounting for 18 percent (3 percent) and 10 percent (7.

  19. Integrated flood risk assessment for the Mekong Delta through the combined assessment of flood hazard change and social vulnerability

    Science.gov (United States)

    Apel, Heiko; Garschagen, Matthias; Delgado, José Miguel; Viet Dung, Nguyen; Van Tuan, Vo; Thanh Binh, Nguyen; Birkmann, Joern; Merz, Bruno

    2013-04-01

    Low lying estuaries as the Mekong Delta in Vietnam are among the most vulnerable areas with respect to climate change impacts. While regular floods are not a threat but an opportunity for livelihoods and income generation, extreme flood events can pose considerable risks to the people living in Deltas. Climate change is expected to increase the frequency of extreme floods globally, which in combination with sea level rise and a likely intensification of cyclone activity creates increased and/or entirely new hazard exposure in the Deltas. Yet, in line with the risk literature and especially the recent IPCC SREX report, flooding risk needs to be understood as deriving from the interaction of physical hazards and the vulnerabilities of exposed elements. Therefore, the paper aims for an integrated risk assessment through combining the most up to date estimates of flood hazard projections under climate change conditions in the Mekong Delta with the assessment of vulnerability patterns. Projections of flood hazard are estimated based the modulation of the flood frequency distribution by atmospheric circulation patterns. Future projections of these patterns are calculated from an ensemble of climate models. A quasi two-dimensional hydrodynamical model of the Delta is then applied to estimate water levels and flood extend. This model is fed with a set of hydrographs which are based on both the derived climate model uncertainty and the bivariate nature of floods in the Mekong Delta. Flood peak is coupled with flood volume in the probabilistic framework to derive synthetic extreme future floods with associated probabilities of occurrence. This flood hazard analysis is combined with static sea level rise scenarios, which alter the lower boundary of the hydrodynamic model and give estimates of the impact on sea level rise on inundation extend and depths. The vulnerability assessment is based on a three step approach. Firstly, vulnerability profiles are developed for different

  20. The combined impact on the flooding in Vietnam's Mekong River delta of local man-made structures, sea level rise, and dams upstream in the river catchment

    Science.gov (United States)

    Le, Thi Viet Hoa; Nguyen, Huu Nhan; Wolanski, Eric; Tran, Thanh Cong; Haruyama, Shigeko

    2007-01-01

    The Mekong River delta plays an important role in the Vietnamese economy and it has been severely impacted during this century by a series of unusually large floods. In the dry season the delta is also impacted by salinity intrusion and tides. These effects have caused severe human hardship. To mitigate these impacts, a large number of engineering structures, primarily dykes and weirs, have been built in the delta in recent years and are still being built, mainly to control floods and saltwater intrusion. These control measures are still being upgraded. A GIS-linked numerical model shows that the flood levels in the delta depend on the combined impacts of high river flows in the Mekong River, storm surges, sea level rise, and the likely, future siltation of the Mekong Estuary resulting from the construction of dams in China as well as many other dams proposed throughout the remaining river catchment. The model suggests that the engineering structures in the delta increase the flow velocities in the rivers and canals, increasing bank erosion, and cause the water to be deeper in the rivers and canals. This increases flooding in the non-protected areas of the delta and increases the risk of catastrophic failure of the dykes in the protected areas. The model also predicts that a sea level rise induced by global warming will enhance flooding in the Mekong River delta in Vietnam, and that flooding may worsen in the long term as a result of estuarine siltation resulting from the construction of dams. At the scale of the Mekong River basin, a multinational water resources management plan is needed that includes the hydrological needs of the delta. At the scale of the delta, a compromise is needed between allowing some flooding necessary for agriculture and preventing catastrophic flooding to alleviate human suffering.

  1. Differences and Commonalities: Farmer Stratifications in the San Luis Valley Research/Extension Project Area. ARE Research Report.

    Science.gov (United States)

    Eckert, Jerry B.

    A research project in the San Luis Valley of Colorado sought to isolate a few unique farm types that could become target groups for the design and implementation of agricultural research and extension programs. Questionnaires were completed by 44 of 65 farmers in one watershed area of Conejos County. Analysis revealed a complex pattern of…

  2. Differences and Commonalities: Farmer Stratifications in the San Luis Valley Research/Extension Project Area. ARE Research Report.

    Science.gov (United States)

    Eckert, Jerry B.

    A research project in the San Luis Valley of Colorado sought to isolate a few unique farm types that could become target groups for the design and implementation of agricultural research and extension programs. Questionnaires were completed by 44 of 65 farmers in one watershed area of Conejos County. Analysis revealed a complex pattern of…

  3. Wind Farms: Modeling and Control

    DEFF Research Database (Denmark)

    Soleimanzadeh, Maryam

    2012-01-01

    provides the state space form of the dynamic wind farm model. The model provides an approximation of the behavior of the flow in wind farms, and obtains the wind speed in the vicinity of each wind turbine. The control algorithms in this work are mostly on the basis of the developed wind farm model......The primary purpose of this work is to develop control algorithms for wind farms to optimize the power production and augment the lifetime of wind turbines in wind farms. In this regard, a dynamical model for wind farms was required to be the basis of the controller design. In the first stage......, a dynamical model has been developed for the wind flow in wind farms. The model is based on the spatial discretization of the linearized Navier-Stokes equation combined with the vortex cylinder theory. The spatial discretization of the model is performed using the Finite Difference Method (FDM), which...

  4. On the possible impact of natural sources of reactive ozone precursors in the valley of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Suarez, L.G.; Martinez, R.; Hernandez, F.

    1996-12-31

    LANDSAT TM images were used to classify land use in the Valley of Mexico. Forest, grass and farming land areas were used to obtain emission inventories of non-methane biogenic hydrocarbons (NMBHC). These may be equivalent to as much as 10% of total reactive organic compounds (ROC) emissions. However these may be on a one to one ratio with the olefinic fraction of anthropogenic ROCs. Grass and farming areas were used to estimate the possible impact of episodic NO emissions from soil after early rains just prior to the onset of rain season.

  5. 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...

  6. Economic and nutrient discharge tradeoffs of excreta-fed aquaculture in the Mekong Delta, Vietnam

    NARCIS (Netherlands)

    Nhan, D.K.; Verdegem, M.C.J.; Binh, N.T.; Duong, L.T.; Milstein, A.; Verreth, J.A.J.

    2008-01-01

    The present study quantifies the effects on production, nutrient discharge and economic return of the use of pig and human excreta in pond tanning. On-farm data from various studies were integrated and analyzed applying single and multiple regression methods. Pond-dissolved oxygen concentration, wat

  7. Wind farm production estimates

    DEFF Research Database (Denmark)

    Larsen, Torben J.; Larsen, Gunner Chr.; Aagaard Madsen, Helge;

    2012-01-01

    on a 3GHz pc. The turbine controller is fully implemented. Initially, production estimates of a single turbine under free and wake conditions, respectively, are compared for (undis- turbed) mean wind speeds ranging from 3m/s to 25m/s. The undisturbed situation refers to a wind direction bin defined......In this paper, the Dynamic Wake Meandering (DWM) model is applied for simulation of wind farm production. In addition to the numerical simulations, measured data have been analyzed in order to provide the basis for a full-scale verification of the model performance. The basic idea behind...... as 270◦ ±5◦, whereas the wake situation refers to the wind direction bin 319◦ ±5◦. In the latter case, the investigated turbine operated in the wake of 6 upstream turbines, with the mean wind direction being equal to the orientation of the wind turbine row. The production of the entire wind farm has been...

  8. Transgenic Farm Animals

    Science.gov (United States)

    Solomon, Morse B.; Eastridge, Janet S.; Paroczay, Ernest W.

    Conventional science to improve muscle and meat parameters has involved breeding strategies, such as selection of dominant traits or selection of preferred traits by cross breeding, and the use of endogenous and exogenous hormones. Improvements in the quality of food products that enter the market have largely been the result of postharvest intervention strategies. Biotechnology is a more extreme scientific method that offers the potential to improve the quality, yield, and safety of food products by direct genetic manipulation. In the December 13, 2007 issue of the Southeast Farm Press, an article by Roy Roberson pointed out that biotechnology is driving most segments of U.S. farm growth. He indicated that nationwide, the agriculture industry is booming and much of that growth is the result of biotechnology advancements.

  9. Particularities of farm accounting

    Directory of Open Access Journals (Sweden)

    Lapteș, R.

    2012-01-01

    Full Text Available Nowadays, agriculture has become one of the most important fields of activity, significant funds being allotted within the EU budget to finance the European agriculture. In this context, organising the accounting of economic entities which carry out their activity in the agricultural sector has acquired new meanings. The goal of the present study is to bring into the light the particularities of the farm accounting on two levels: on the one hand, from the perspective of the international accounting referential and, on the other hand, in compliance with the national accounting regulations. The most important conclusion of this work is that, in post-1990 Romania, no interest was further manifested for the refinement of aspects specific to farm accounting.

  10. Organic food and farming

    DEFF Research Database (Denmark)

    Kledal, Paul Rye

    The paper is based on research conducted for DARCOF II (Danish Research Centre for Organic Farming, www.darcof.dk). The aim of the research project is to analyze the future development of the Danish organic food sector through focusing on two agro-commodities: vegetables and pork. Emphasis...... is placed on identification of economic forces within the supply chains. The main conclusions of the paper – being the results from the organic vegetable chain – are that the rules and regulations, and the development of alternative transaction processes in organic food and farming have so far been founded...... conventional farmers – declining prices, concentration of production and shift in bargaining power to the retailers. Logically, this situation will lead eventually to increasing conflicts between organic values and their subordination to free market forces, i.e. conventionalization. In the same time retailers...

  11. 27 CFR 9.82 - Potter Valley.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Potter Valley. 9.82... Potter Valley. (a) Name. The name of the viticultural area described in this section is “Potter Valley.” (b) Approved map. The approved maps for the Potter Valley viticultural area are the U.S.G.S....

  12. Amy Courtney: Freewheelin' Farm

    OpenAIRE

    Rabkin, Sarah

    2010-01-01

    Shareholders in Freewheelin’ Farm’s community supported agriculture program enjoy an unusual perk: delivery by bicycle-drawn trailer. Freewheelin’ founder Amy Courtney, a 1997 graduate of UCSC’s Apprenticeship in Ecological Horticulture, strives to produce fresh, healthy food while minimizing her environmental footprint. Courtney started the farm in 2002 with almost no motorized vehicles, incorporating used equipment and recycled materials wherever possible in the farm’s operations. She and h...

  13. 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

  14. Wind farm production estimates

    DEFF Research Database (Denmark)

    Larsen, Torben J.; Larsen, Gunner Chr.; Aagaard Madsen, Helge

    2012-01-01

    In this paper, the Dynamic Wake Meandering (DWM) model is applied for simulation of wind farm production. In addition to the numerical simulations, measured data have been analyzed in order to provide the basis for a full-scale verification of the model performance. The basic idea behind the DWMm......In this paper, the Dynamic Wake Meandering (DWM) model is applied for simulation of wind farm production. In addition to the numerical simulations, measured data have been analyzed in order to provide the basis for a full-scale verification of the model performance. The basic idea behind...... on a 3GHz pc. The turbine controller is fully implemented. Initially, production estimates of a single turbine under free and wake conditions, respectively, are compared for (undis- turbed) mean wind speeds ranging from 3m/s to 25m/s. The undisturbed situation refers to a wind direction bin defined...... as 270◦ ±5◦, whereas the wake situation refers to the wind direction bin 319◦ ±5◦. In the latter case, the investigated turbine operated in the wake of 6 upstream turbines, with the mean wind direction being equal to the orientation of the wind turbine row. The production of the entire wind farm has been...

  15. Modelling Farm Animal Welfare.

    Science.gov (United States)

    Collins, Lisa M; Part, Chérie E

    2013-05-16

    The use of models in the life sciences has greatly expanded in scope and advanced in technique in recent decades. However, the range, type and complexity of models used in farm animal welfare is comparatively poor, despite the great scope for use of modeling in this field of research. In this paper, we review the different modeling approaches used in farm animal welfare science to date, discussing the types of questions they have been used to answer, the merits and problems associated with the method, and possible future applications of each technique. We find that the most frequently published types of model used in farm animal welfare are conceptual and assessment models; two types of model that are frequently (though not exclusively) based on expert opinion. Simulation, optimization, scenario, and systems modeling approaches are rarer in animal welfare, despite being commonly used in other related fields. Finally, common issues such as a lack of quantitative data to parameterize models, and model selection and validation are discussed throughout the review, with possible solutions and alternative approaches suggested.

  16. Modelling Farm Animal Welfare

    Directory of Open Access Journals (Sweden)

    Chérie E. Part

    2013-05-01

    Full Text Available The use of models in the life sciences has greatly expanded in scope and advanced in technique in recent decades. However, the range, type and complexity of models used in farm animal welfare is comparatively poor, despite the great scope for use of modeling in this field of research. In this paper, we review the different modeling approaches used in farm animal welfare science to date, discussing the types of questions they have been used to answer, the merits and problems associated with the method, and possible future applications of each technique. We find that the most frequently published types of model used in farm animal welfare are conceptual and assessment models; two types of model that are frequently (though not exclusively based on expert opinion. Simulation, optimization, scenario, and systems modeling approaches are rarer in animal welfare, despite being commonly used in other related fields. Finally, common issues such as a lack of quantitative data to parameterize models, and model selection and validation are discussed throughout the review, with possible solutions and alternative approaches suggested.

  17. Assessment of the Impact of Reservoirs in the Upper Mekong River Using Satellite Radar Altimetry and Remote Sensing Imageries

    Directory of Open Access Journals (Sweden)

    Kuan-Ting Liu

    2016-04-01

    Full Text Available Water level (WL and water volume (WV of surface-water bodies are among the most crucial variables used in water-resources assessment and management. They fluctuate as a result of climatic forcing, and they are considered as indicators of climatic impacts on water resources. Quantifying riverine WL and WV, however, usually requires the availability of timely and continuous in situ data, which could be a challenge for rivers in remote regions, including the Mekong River basin. As one of the most developed rivers in the world, with more than 20 dams built or under construction, Mekong River is in need of a monitoring system that could facilitate basin-scale management of water resources facing future climate change. This study used spaceborne sensors to investigate two dams in the upper Mekong River, Xiaowan and Jinghong Dams within China, to examine river flow dynamics after these dams became operational. We integrated multi-mission satellite radar altimetry (RA, Envisat and Jason-2 and Landsat-5/-7/-8 Thematic Mapper (TM/Enhanced Thematic Mapper plus (ETM+/Operational  Land Imager (OLI optical remote sensing (RS imageries to construct composite WL time series with enhanced spatial resolutions and substantially extended WL data records. An empirical relationship between WL variation and water extent was first established for each dam, and then the combined long-term WL time series from Landsat images are reconstructed for the dams. The R2 between altimetry WL and Landsat water area measurements is >0.95. Next, the Tropical Rainfall Measuring Mission (TRMM data were used to diagnose and determine water variation caused by the precipitation anomaly within the basin. Finally, the impact of hydrologic dynamics caused by the impoundment of the dams is assessed. The discrepancy between satellite-derived WL and available in situ gauge data, in term of root-mean-square error (RMSE is at 2–5 m level. The estimated WV variations derived from combined RA

  18. Two-stage-six-objective calibration of a hydrodynamic-based sediment transport model for the Mekong Delta

    Science.gov (United States)

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

    2014-05-01

    An advection-dispersive (AD) module for cohesive sediment transport modelling is built up based on a quasi-2D hydrodynamic model (HD) for the whole Mekong Delta which has been recently developed by Dung et al. (2011) using the modelling software DHI MIKE 11. As parameter uncertainty is one main epistemic uncertainty source of modelling work, it needs to be reduced via a calibration-validation process in order to improve the modelling skill of the simulation tool. In this large scale two-component (HD-AD) model, many parameters need to be properly estimated. These parameters include the flow resistance coefficient (Manning's roughness coefficient), longitudinal dispersion coefficient, the free settling velocity and the critical shear stress for deposition. It should be noted that they are spatially distributed over the modelling domain which consists of more than 4000 branches and 26000 computational nodes used to model real channels and floodplains for the vast area in the Mekong Delta. We aim at developing a suitable framework for optimizing these parameters automatically. As the model included a real 1D illustration of river and channel networks and quasi-2D presentation of floodplains being able to represent both main flow and inundation processes, the calibration is, hence, seen from a multi-objective viewpoint using in parallel high-temporal, low-spatial resolution data (gauge data) and low-temporal, high spatial resolution data (remote sensing data). The calibration (and validation) data utilized in this study comprise of gauged time series data along the main channel (water level, flow discharge and suspended sediment concentration), satellite-based flood extent maps and monitored sedimentation deposition rates in several locations. In total, six objective functions as calibration criteria are defined based on these data. Learning from the feature that AD module can be simulated using finer computational time step after HD results are computed, we propose to

  19. CRIA Sians A areement with Rubber Valley

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The signing ceremony of establishing strategic partnership between China Rubber Industry Association and Rubber Valley Co., Ltd. was held in Rubber Valley on September 13. Leaders such as Xu Wenying, Deputy Secretary-General of CRIA, repre-senting CRIA, and Zhang Yan, Deputy Director of Rubber Valley Management Committee and General Manager of Rubber Valley Co., Ltd., representing Rubber Valley, signed on the cooperation agreement. Fan Rende, President of CRIA, Cai Quanji,

  20. Accelerating optimization by tracing valley

    Science.gov (United States)

    Li, Qing-Xiao; He, Rong-Qiang; Lu, Zhong-Yi

    2016-06-01

    We propose an algorithm to accelerate optimization when an objective function locally resembles a long narrow valley. In such a case, a conventional optimization algorithm usually wanders with too many tiny steps in the valley. The new algorithm approximates the valley bottom locally by a parabola that is obtained by fitting a set of successive points generated recently by a conventional optimization method. Then large steps are taken along the parabola, accompanied by fine adjustment to trace the valley bottom. The effectiveness of the new algorithm has been demonstrated by accelerating the Newton trust-region minimization method and the Levenberg-Marquardt method on the nonlinear fitting problem in exact diagonalization dynamical mean-field theory and on the classic minimization problem of the Rosenbrock's function. Many times speedup has been achieved for both problems, showing the high efficiency of the new algorithm.

  1. Mississippi River Valley alluvial aquifer

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the extent of the Mississippi River Valley alluvial aquifer in the states of Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and...

  2. The History of Silicon Valley

    Institute of Scientific and Technical Information of China (English)

    Joseph Leu

    2005-01-01

    @@ Just as Manchester was once the center for indus trial progress, the microelectronics industry also has a heartland. Silicon Valley is located in a thirty by ten miles strip between San Francisco and San Jose,California.

  3. RailroadValleySpringfish_CH

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — These data identify the areas where final critical habitat for the Railroad Valley springfish (Crenichthys nevadae) occur. The irrigation ditch that is on the north...

  4. Social Networks in Silicon Valley

    Institute of Scientific and Technical Information of China (English)

    Joseph; Leu

    2006-01-01

      Social network is a dominant, distinguishing characteristic of Silicon Valley. Because innovation entails coping with a high degree of uncertainty,such innovation is particularly dependent on networks.……

  5. Mapping Evapotranspiration over Agricultural Land in the California Central Valley

    Science.gov (United States)

    Melton, F. S.; Huntington, J. L.; Guzman, A.; Johnson, L.; Morton, C.; Nemani, R. R.; Post, K. M.; Rosevelt, C.; Shupe, J. W.; Spellenberg, R.; Vitale, A.

    2015-12-01

    Recent advances in satellite mapping of evapotranspiration (ET) have made it possible to largely automate the process of mapping ET over large areas at the field-scale. This development coincides with recent drought events across the western U.S. which have intensified interest in mapping of ET and consumptive use to address a range of water management challenges, including resolving disputes over water rights, improving irrigation management, and developing sustainable management plans for groundwater resources. We present a case study for California that leverages two automated ET mapping capabilities to estimate ET at the field scale over agricultural areas in the California Central Valley. We utilized the NASA Earth Exchange and applied a python-based implementation of the METRIC surface energy balance model and the Satellite Irrigation Management Support (SIMS) system, which uses a surface reflectance-based approach, to map ET over agricultural areas in the Central Valley. We present estimates from 2014 from both approaches and results from a comparison of the estimates. Though theoretically and computationally quite different from each other, initial results from both approaches show good agreement overall on seasonal ET totals for 2014. We also present results from comparisons against ET measurements collected on commercial farms in the Central Valley and discuss implications for accuracy of the two different approaches. The objective of this analysis is to provide data that can inform planning for the development of sustainable groundwater management plans, and assist water managers and growers in evaluating irrigation demand during drought events.

  6. A hierarchical network approach for modeling Rift Valley fever epidemics with applications in North America.

    Directory of Open Access Journals (Sweden)

    Ling Xue

    Full Text Available Rift Valley fever is a vector-borne zoonotic disease which causes high morbidity and mortality in livestock. In the event Rift Valley fever virus is introduced to the United States or other non-endemic areas, understanding the potential patterns of spread and the areas at risk based on disease vectors and hosts will be vital for developing mitigation strategies. Presented here is a general network-based mathematical model of Rift Valley fever. Given a lack of empirical data on disease vector species and their vector competence, this discrete time epidemic model uses stochastic parameters following several PERT distributions to model the dynamic interactions between hosts and likely North American mosquito vectors in dispersed geographic areas. Spatial effects and climate factors are also addressed in the model. The model is applied to a large directed asymmetric network of 3,621 nodes based on actual farms to examine a hypothetical introduction to some counties of Texas, an important ranching area in the United States of America. The nodes of the networks represent livestock farms, livestock markets, and feedlots, and the links represent cattle movements and mosquito diffusion between different nodes. Cattle and mosquito (Aedes and Culex populations are treated with different contact networks to assess virus propagation. Rift Valley fever virus spread is assessed under various initial infection conditions (infected mosquito eggs, adults or cattle. A surprising trend is fewer initial infectious organisms result in a longer delay before a larger and more prolonged outbreak. The delay is likely caused by a lack of herd immunity while the infection expands geographically before becoming an epidemic involving many dispersed farms and animals almost simultaneously. Cattle movement between farms is a large driver of virus expansion, thus quarantines can be efficient mitigation strategy to prevent further geographic spread.

  7. A hierarchical network approach for modeling Rift Valley fever epidemics with applications in North America.

    Science.gov (United States)

    Xue, Ling; Cohnstaedt, Lee W; Scott, H Morgan; Scoglio, Caterina

    2013-01-01

    Rift Valley fever is a vector-borne zoonotic disease which causes high morbidity and mortality in livestock. In the event Rift Valley fever virus is introduced to the United States or other non-endemic areas, understanding the potential patterns of spread and the areas at risk based on disease vectors and hosts will be vital for developing mitigation strategies. Presented here is a general network-based mathematical model of Rift Valley fever. Given a lack of empirical data on disease vector species and their vector competence, this discrete time epidemic model uses stochastic parameters following several PERT distributions to model the dynamic interactions between hosts and likely North American mosquito vectors in dispersed geographic areas. Spatial effects and climate factors are also addressed in the model. The model is applied to a large directed asymmetric network of 3,621 nodes based on actual farms to examine a hypothetical introduction to some counties of Texas, an important ranching area in the United States of America. The nodes of the networks represent livestock farms, livestock markets, and feedlots, and the links represent cattle movements and mosquito diffusion between different nodes. Cattle and mosquito (Aedes and Culex) populations are treated with different contact networks to assess virus propagation. Rift Valley fever virus spread is assessed under various initial infection conditions (infected mosquito eggs, adults or cattle). A surprising trend is fewer initial infectious organisms result in a longer delay before a larger and more prolonged outbreak. The delay is likely caused by a lack of herd immunity while the infection expands geographically before becoming an epidemic involving many dispersed farms and animals almost simultaneously. Cattle movement between farms is a large driver of virus expansion, thus quarantines can be efficient mitigation strategy to prevent further geographic spread.

  8. Are large farms more efficient? Tenure security, farm size and farm efficiency: evidence from northeast China

    Science.gov (United States)

    Zhou, Yuepeng; Ma, Xianlei; Shi, Xiaoping

    2017-04-01

    How to increase production efficiency, guarantee grain security, and increase farmers' income using the limited farmland is a great challenge that China is facing. Although theory predicts that secure property rights and moderate scale management of farmland can increase land productivity, reduce farm-related costs, and raise farmer's income, empirical studies on the size and magnitude of these effects are scarce. A number of studies have examined the impacts of land tenure or farm size on productivity or efficiency, respectively. There are also a few studies linking farm size, land tenure and efficiency together. However, to our best knowledge, there are no studies considering tenure security and farm efficiency together for different farm scales in China. In addition, there is little study analyzing the profit frontier. In this study, we particularly focus on the impacts of land tenure security and farm size on farm profit efficiency, using farm level data collected from 23 villages, 811 households in Liaoning in 2015. 7 different farm scales have been identified to further represent small farms, median farms, moderate-scale farms, and large farms. Technical efficiency is analyzed with stochastic frontier production function. The profit efficiency is regressed on a set of explanatory variables which includes farm size dummies, land tenure security indexes, and household characteristics. We found that: 1) The technical efficiency scores for production efficiency (average score = 0.998) indicate that it is already very close to the production frontier, and thus there is little room to improve production efficiency. However, there is larger space to raise profit efficiency (average score = 0.768) by investing more on farm size expansion, seed, hired labor, pesticide, and irrigation. 2) Farms between 50-80 mu are most efficient from the viewpoint of profit efficiency. The so-called moderate-scale farms (100-150 mu) according to the governmental guideline show no

  9. Distribution of diazotrophic microorganisms and nifH gene expression in the Mekong River plume during intermonsoon

    DEFF Research Database (Denmark)

    Bombar, Deniz; Moisander, Pia H.; Dippner, Joachim W.

    2011-01-01

    N 2 fixation by marine pelagic prokaryotes plays a critical role in supplying new N to the ocean, and there is growing evidence that oceanic N 2 fixation is generally enhanced in tropical river plumes, where N 2 fixers (diazotrophs) benefit from riverine phosphorus and/or iron. Here we used nif......H gene quantitative polymerase chain reaction (QPCR) and reverse transcription (RT) QPCR to investigate the horizontal distribution and activity of 9 diazotroph phylotypes in the Mekong River plume, South China Sea (SCS), in April 2007 (intermonsoon, lowest annual discharge). The nifH gene diversity...... was investigated by cloning and sequencing. Hydrodynamic modeling of the surface water advection revealed that the same water masses were sampled during the entire study, and helped to elucidate the physical forcing on diazotroph abundances and distributions. According to our estimates of nifH abundances...

  10. The 2011 flood event in the Mekong Delta: preparedness, response, damage and recovery of private households and small businesses.

    Science.gov (United States)

    Chinh, Do Thi; Bubeck, Philip; Dung, Nguyen Viet; Kreibich, Heidi

    2016-10-01

    Floods frequently cause substantial economic and human losses, particularly in developing countries. For the development of sound flood risk management schemes that reduce flood consequences, detailed insights into the different components of the flood risk management cycle, such as preparedness, response, flood impact analyses and recovery, are needed. However, such detailed insights are often lacking: commonly, only (aggregated) data on direct flood damage are available. Other damage categories such as losses owing to the disruption of production processes are usually not considered, resulting in incomplete risk assessments and possibly inappropriate recommendations for risk management. In this paper, data from 858 face-to-face interviews among flood-prone households and small businesses in Can Tho city in the Vietnamese Mekong Delta are presented to gain better insights into the damage caused by the 2011 flood event and its management by households and businesses. © 2016 The Author(s). Disasters © Overseas Development Institute, 2016.

  11. Climate change, water quality, and water-related diseases in the Mekong Delta Basin: a systematic review.

    Science.gov (United States)

    Phung, Dung; Huang, Cunrui; Rutherford, Shannon; Chu, Cordia; Wang, Xiaoming; Nguyen, Minh

    2015-04-01

    Mekong Delta Basin (MDB) is vulnerable to extreme climate and hydrological events. The objectives of this review are to understand of water related health effects exacerbated by climate change and the gaps of knowledge on the relationships between climate conditions, water quality, and water-related diseases in the MDB. The findings indicate that a few studies with qualitative emphases on the relationships between climate and water quality have been conducted in MDB, and they are insufficient to describe the pattern of climate-disease relationship. The diseases caused by chemical contaminants in relation to changes of climate conditions are neglected in MDB. We suggest further studies to examine the influence of short-term variation of climate conditions on water quality and water-related diseases for the purpose of public health and medical prevention, and due to the trans-boundary nature of MDB, developing partnership in data sharing and research collaboration among MDBs countries should be prioritized. © 2015 APJPH.

  12. Fault Tolerant Wind Farm Control

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob

    2013-01-01

    with best at a wind turbine control level. However, some faults are better dealt with at the wind farm control level, if the wind turbine is located in a wind farm. In this paper a benchmark model for fault detection and isolation, and fault tolerant control of wind turbines implemented at the wind farm...... control level is presented. The benchmark model includes a small wind farm of nine wind turbines, based on simple models of the wind turbines as well as the wind and interactions between wind turbines in the wind farm. The model includes wind and power references scenarios as well as three relevant fault...... scenarios. This benchmark model is used in an international competition dealing with Wind Farm fault detection and isolation and fault tolerant control....

  13. Seasonality, disease and behavior: using multiple methods to explore socio-environmental health risks in the Mekong Delta.

    Science.gov (United States)

    Few, Roger; Lake, Iain; Hunter, Paul R; Tran, Pham Gia

    2013-03-01

    Any analysis of how changing environmental hazards impact on public health is fundamentally constrained unless it recognizes the centrality of the social and behavioral dimensions of risk. This paper reports on a research project conducted among low-income peri-urban households in the Mekong Delta of Vietnam. The research was based on cross-disciplinary inputs to develop a multi-layered understanding of the implications of a dynamic seasonal environment for diarrheal disease risk. It is a widely held assumption that the major changes in the abundance of surface water between the flood and dry seasons in the Mekong Delta are likely to be reflected in the changing patterns of disease risk, especially for poorer households that tend to rely heavily on river water for domestic water use. Therefore, this study investigated seasonal patterns in the contamination of environmental water, incidences of diarrheal illnesses, water use and hygiene behavior, together with perceptions of health risks and seasonality. During the period of October 2007 to October 2008, the UK and Vietnamese research team worked with a total of 120 households in four low-income sites around the city of Long Xuyen to conduct water testing; administer questionnaires on self-reported health, risk perceptions and behavior; and conduct semi-structured interviews. The research team found no overall evidence of a systematic seasonal risk pattern. At the population level, marginal temporal variations in water quality in the environment failed to translate into health outcomes. A complex risk narrative emerged from the interweaving data elements, demonstrating major inter- and intra-household variations in risk perceptions, hygiene behavior, seasonal behavior and other risk factors. It is suggested that these complexities of human behavior and transmission routes challenge simplistic assumptions about change in health outcomes as a result of seasonal environmental changes. These findings demonstrate the key

  14. 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.

  15. 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.

  16. Implementation of forest cover and carbon mapping in the Greater Mekong subregion and Malaysia project - A case study of Thailand

    Science.gov (United States)

    Pungkul, S.; Suraswasdi, C.; Phonekeo, V.

    2014-02-01

    The Great Mekong Subregion (GMS) contains one of the world's largest tropical forests and plays a vital role in sustainable development and provides a range of economic, social and environmental benefits, including essential ecosystem services such as climate change mitigation and adaptation. However, the forest in this Subregion is experiencing deforestation rates at high level due to human activities. The reduction of the forest area has negative influence to the environmental and natural resources issues, particularly, more severe disasters have occurred due to global warming and the release of the greenhouse gases. Therefore, in order to conduct forest management in the Subregion efficiently, the Forest Cover and Carbon Mapping in Greater Mekong Subregion and Malaysia project was initialized by the Asia-Pacific Network for Sustainable Forest Management and Rehabilitation (APFNet) with the collaboration of various research institutions including Institute of Forest Resource Information Technique (IFRIT), Chinese Academy of Forestry (CAF) and the countries in Sub region and Malaysia comprises of Cambodia, the People's Republic of China (Yunnan province and Guangxi province), Lao People's Democratic Republic, Malaysia, Myanmar, Thailand, and Viet Nam. The main target of the project is to apply the intensive use of recent satellite remote sensing technology, establishing regional forest cover maps, documenting forest change processes and estimating carbon storage in the GMS and Malaysia. In this paper, the authors present the implementation of the project in Thailand and demonstrate the result of forest cover mapping in the whole country in 2005 and 2010. The result of the project will contribute towards developing efficient tools to support decision makers to clearly understand the dynamic change of the forest cover which could benefit sustainable forest resource management in Thailand and the whole Subregion.

  17. Seasonal variability in the sources of particulate organic matter of the Mekong River as discerned by elemental and lignin analyses

    Science.gov (United States)

    Ellis, Erin E.; Keil, Richard G.; Ingalls, Anitra E.; Richey, Jeffrey E.; Alin, Simone R.

    2012-03-01

    The Mekong River ranks within the top ten rivers of the world in terms of water discharge and sediment load to the ocean, yet its organic matter (OM) composition remains unstudied. This river is experiencing anthropogenically forced changes due to land use and impoundment, and these changes are expected to intensify in the future. Accordingly, we monitored the composition (including vascular-plant signatures) of Mekong River fine particulate organic matter (FPOM) over a one-year period. Autochthonous production comprises a greater proportion of FPOM during the dry season than in the rainy season, as demonstrated by higher percent organic carbon values (7.9 ± 2.4 versus 2.2 ± 0.4%), lower yields of lignin normalized to carbon (0.40 ± 0.05 versus 1.1 ± 0.3 mg (100 mg OC)-1), and an increase in N:C ratios toward phytoplankton values during the dry season (from 0.06 to 0.12). Changes in the lignin-phenol composition of FPOM suggest that gymnosperms contribute more toward FPOM composition during the dry season, with angiosperms dominating in the wet season. This is supported by calculations of the lignin phenol vegetation index of riverine FPOM, which increases between the dry to wet seasons (dry: 29.4 ± 15.0 versus wet: 74.6 ± 17.3). These changes likely reflect seasonal differences in the proportion of flow that is coming from the Upper and Lower Basin, corresponding to compositional differences between the vegetation of these regions. Therefore, this work provides a baseline understanding of FPOM variability that can be used to assess how future change will affect this river.

  18. Prevalence of risk factors for non-communicable diseases in the Mekong Delta, Vietnam: results from a STEPS survey

    Directory of Open Access Journals (Sweden)

    Pham Luc H

    2009-08-01

    Full Text Available Abstract Background Despite the increasing burden of non-communicable diseases (NCD in Vietnam, information on the prevalence of preventable risk factors for NCD is restricted to the main urban centres of Ha Noi, and Ho Chi Minh City (HCMC. This population-based survey aimed to describe the prevalence of risk factors for NCD in a rural Vietnamese sample. Methods This survey was conducted using the WHO "STEPwise approach to surveillance of non-communicable diseases" (STEPS methodology. Participants (n = 1978 were residents of the Mekong Delta region selected by multi-stage sampling. Standardised international protocols were used to measure behavioural risk factors (smoking, alcohol consumption, fruit and vegetable consumption, physical activity, physical characteristics (weight, height, waist and hip circumferences, blood pressure – BP, fasting blood glucose (BG and total cholesterol (TC. Data were analysed using complex survey analysis methods. Results In this sample, 8.8% of men and 12.6% of women were overweight (body mass index (BMI ≥ 25 kg/m2 and 2.3% of men and 1.5% of women were obese (BMI ≥ 30 kg/m2. The prevalence of hypertension (systolic BP ≥ 140 mmHg and/or diastolic BP ≥ 90 mmHg, or taking medication for hypertension was 27.3% for men and 16.2% for women. There were 1.0% of men and 1.1% of women with raised BG (defined as capillary whole BG of at least 6.1 mmol/L. Conclusion We provide the first NCD risk factor profile of people living in the Mekong Delta of Vietnam using standardised methodology. Our findings for this predominantly rural sample differ from previous studies conducted in Ha Noi and HCMC, and suggest that it is inappropriate to generalise findings from the big-city surveys to the other 80% of the population.

  19. Arsenic contamination in the food chain and its risk assessment of populations residing in the Mekong River basin of Cambodia.

    Science.gov (United States)

    Phan, Kongkea; Sthiannopkao, Suthipong; Heng, Savoeun; Phan, Samrach; Huoy, Laingshun; Wong, Ming Hung; Kim, Kyoung-Woong

    2013-11-15

    In the present study, we investigated the potential arsenic exposure of Cambodian residents from their daily food consumption. Environmental and ecological samples such as paddy soils, paddy rice (unhusked), staple rice (uncooked and cooked), fish and vegetables were collected from Kandal, Kratie and Kampong Cham provinces in the Mekong River basin of Cambodia. After acid-digestion, digestates were chemically analyzed by inductively coupled plasma mass spectrometry. Results revealed that the means of total arsenic concentration ([As]tot) in paddy soils and paddy rice from Kandal were significantly higher than those from Kampong Cham province (t-test, parsenic intake from food consumption indicated that the upper end of the range of the daily dose of inorganic arsenic for Kandal residents (0.089-8.386 μg d(-1) kg(-1) body wt.) was greater than the lower limits on the benchmark dose for a 0.5% increased incidence of lung cancer (BMDL0.5 is equal to 3.0 μg d(-1) kg(-1) body wt.). The present study suggests that the residents in Kandal are at risk of arsenic intake from their daily food consumption. However, the residents in Kratie and Kampong Cham provinces are less likely to be exposed to arsenic through their daily dietary intake. To the best of our knowledge, this is the first report estimating the daily intake and daily dose of inorganic arsenic from food consumption in the Mekong River basin of Cambodia. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Social Farming Rural Development Strategy

    Directory of Open Access Journals (Sweden)

    Adrian Gheorghe ZUGRAVU

    2013-12-01

    Full Text Available The paper follows two main objectives: to understand farmers’ perception and image of social services and to identify communication levers in order to improve the perceived image of social farming. Orientations in terms of communication are product-focused and aim at enhancing the reputation of social farming consequently with impact on rural development. This paper conducted a questionnaire survey of Romanian farmers’ perception toward social agricultural. The empirical study indicated that farmers shown different awareness to social farming.

  1. Understanding crop and farm management

    OpenAIRE

    Chongtham, Iman Raj

    2016-01-01

    Agriculture faces challenges in meeting rising demand for food, feed, fibre and fuel while coping with pressure from globalisation, limited natural resources and climate change. Farmers will choose management practices based on their goals and available resources and these practices will influence farm performance. The aim of this thesis was to understand farmers’ crop and farm management practices and their links to farm(er) characteristics, productivity, biodiversity, marketing channels and...

  2. Design and farm animal welfare.

    Science.gov (United States)

    Jackson, W T

    1976-07-24

    Farm animal welfare and the design of farm buildings and equipment are interrelated. The animals' requirements and preferences should first be estimated and ways in which this can be done are discussed, as are methods of assessment of their environment. Some examples of the influence which housing and equipment design can have are given. Attention is drawn to the difficulties inherent in the assessment of farm animal welfare and the postulation made that the veterinarian is well fitted to carry out such assessments.

  3. FarmVille For Dummies

    CERN Document Server

    Morales, Angela

    2011-01-01

    The only how-to, full-color book available on the game sensation FarmVille. With more than 80 million active players since the game?s release in 2009, there seems no end to the growing popularity of FarmVille. Whether accessed through the Facebook application or from the game?s Web site, this application is a worldwide phenomenon. Yet, there has been no beginner guide that offers an introduction to newcomers and updates to experienced players?until now. FarmVille For Dummies is aimed at getting novices acquainted with FarmVille rules and regulations, while more savvy players can sharpen their

  4. Immigrant Workers and Farm Performance

    DEFF Research Database (Denmark)

    Malchow-Møller, Nikolaj; Munch, Jakob R.; Seidelin, Claus Aastrup

    2013-01-01

    In many developed countries, the agricultural sector has experienced a significant inflow of immigrants. At the same time, agriculture is still in a process of structural transformation, resulting in fewer but larger and presumably more efficient farms. We exploit matched employer-employee data...... for Danish farms in 1980–2008 to analyze the micro-level relationship between these two developments. Farms employing immigrants tend to be both larger than and no less productive than other farms. Furthermore, an increased use of immigrants is associated with an improvement in job creation and revenue......, which at least partially seems to reflect a causal effect of immigrants....

  5. Livelihood Strategies in Shaxi, Southwest China: Conceptualizing Mountain–Valley Interactions as a Human–Environment System

    Directory of Open Access Journals (Sweden)

    Franz K. Huber

    2015-03-01

    Full Text Available This paper investigates the socio-ecological differences and interactions between upland and lowland areas in Shaxi Valley, Yunnan Province, Southwest China. As an analytical tool we used an extended Human–Environment System Framework by focusing particularly on the dynamics and sustainability of livelihood strategies and mountain–valley interactions. Drawing from household surveys conducted in two mountain and two valley communities in 2005 and 2009, we show that the distinct income gap between mountain and valley households in 2005 ceased to exist in 2009. The main drivers for this development are the local tourist industry, persistent demand for forest resources, as well as local off-farm and seasonal migrant employment.

  6. Antagonism of local isolates of Trichoderna spp.on citrus root rot disease by Fusarium solani in the mekong delta of vietnam

    Institute of Scientific and Technical Information of China (English)

    Duong Minh; Jozef Coosemans; Le Lam Cuong; Ester Vandersmissen; Pham Van Kim

    2004-01-01

    @@ The local isolates of Trichoderrma spp. and Fusariun solani were colected from citrus orchards in the Mekong delta of Vietnam and isolated on PDA, PDB and TSM medium for antagonism and Koch's postulate testing. The results showed that the high chitinolytic enzymes content of Trichoderma isolates can antagonise with Fusarium solani isolates by preventing the germination of Fusarium macroconidia in in-vitro condition. There are five promising isolates of Trichoderna spp. having high antagonism with Fusarium solani. These Trichoderma isolates also grew well in rice straws, maize stems, weeds and water hyacinth biowaste materials. These results supply the promising trend for biological control of root rot disease on citrus orchards of the Mekong delta.

  7. 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.

  8. Spatial allocation of farming systems and farming indicators in Europe

    DEFF Research Database (Denmark)

    Kempen, Markus; Elbersen, Berien S.; Staritsky, Igor

    2011-01-01

    sample farms making it possible to aggregate farm types both to natural and to lower scale administrative regions. This spatial flexibility allows providing input data to economic or bio-physical models at their desired resolution. The allocation approach is implemented as a constrained optimization...

  9. Energy balance in IPM rice farms compared to conventional farms

    Directory of Open Access Journals (Sweden)

    Mehdi Fazeli

    2017-06-01

    Full Text Available Integrated Pest Management based on Farmer Field Schools (IPM/FFS is a program aimed to guide farmers toward managing agricultural pests in an environmentally responsible manner. This program has been in practice during the recent decade in the north of Iran. A study was conducted to evaluate the overall impacts of IPM/FFS program on energy balance and economic revenue of paddy (Oryza sativa L. farms compared with conventional farms (no IPM. The data of inputs, management practices, and output (yield of 238 paddy farms (135 IPM farms and 103 conventional farms located in a semi-Mediterranean climate were collected in 2010 and 2011. Total energy input, energy output, energy efficiency, and energy productivity were determined as indicators of energy balance. The total energy requirement for paddy production in IPM system was 48756 MJ ha−1, indicating that 8% more energy was used in IPM farms than that in conventional farms. It was noticed that IPM program in this region failed to reduce the consumption of chemical pesticides in paddy farms and the conventional system was more energy efficient than IPM system. Although paddy yield of the two systems was similar, the economic net return in IPM system was almost 20% higher than the conventional system due to the higher price of paddy produced in IPM system.

  10. Whole Farm Nutrient Balance Calculator for New York Dairy Farms

    Science.gov (United States)

    Soberon, Melanie A.; Ketterings, Quirine M.; Rasmussen, Caroline N.; Czymmek, Karl J.

    2013-01-01

    Nutrient loss and accumulation as well as associated environmental degradation have been a concern for animal agriculture for many decades. Federal and New York (NY) regulations apply to Concentrated Animal Feeding Operations and a comprehensive nutrient management plan (CNMP) is required for regulated farms. The whole farm nutrient mass balance…

  11. Whole Farm Nutrient Balance Calculator for New York Dairy Farms

    Science.gov (United States)

    Soberon, Melanie A.; Ketterings, Quirine M.; Rasmussen, Caroline N.; Czymmek, Karl J.

    2013-01-01

    Nutrient loss and accumulation as well as associated environmental degradation have been a concern for animal agriculture for many decades. Federal and New York (NY) regulations apply to Concentrated Animal Feeding Operations and a comprehensive nutrient management plan (CNMP) is required for regulated farms. The whole farm nutrient mass balance…

  12. Spatial allocation of farming systems and farming indicators in Europe

    NARCIS (Netherlands)

    Kempen, M.; Elbersen, B.S.; Staritsky, I.G.; Andersen, E.; Heckelei, T.

    2011-01-01

    In this article an approach to spatially allocate farm information to a specific environmental context is presented. At this moment the European wide farm information is only available at a rather aggregated administrative level. The suggested allocation approach adds a spatial dimension to all samp

  13. Reactive and unreactive iron minerals hosting arsenic within seasonal wetland sediments of the Mekong Delta

    Science.gov (United States)

    Stuckey, J.; Schaefer, M.; Lezama, J.; Dittmar, J.; Fendorf, S.

    2013-12-01

    Millions of people in the deltaic regions of S/SE Asia regularly consume arsenic contaminated groundwater. Within the Mekong Delta of Cambodia, for example, arsenic persists within the groundwater despite being flushed by several pore volumes of recharge. The identity and reactivity of the minerals contributing to the persistence of arsenic in the deltaic aquifers remain elusive. Here we seek to define the molecular form of the arsenic and its host phases along defined flow paths in seasonally saturated wetlands: i) a grassland flooded for ~ 3 - 4 months of the year (Grassland) and ii) an abandoned river channel saturated for ~ 5 - 6 months (Oxbow). Sediment cores were retrieved by pounding aluminum cores into a fresh profile exposed by successive excavation. The cores were sealed with melted wax in the field and stored at 4 °C until processed. Depths of 0.2 to 6 m were sampled at the Grassland site and 0.2 to 4 m at the Oxbow site. Sediments were dried under 95%N2/5%H2 atmosphere. A 1 M HCl extraction dissolving the 'reactive' iron (predominantly poorly crystalline iron oxides) solubilized 3 - 7 % of the total iron in the Grassland site and 8 - 41 % in the Oxbow site. A citrate-bicarbonate-dithionite (CBD) extraction was performed to extract reducible iron (predominantly iron oxides), accounting for 35 - 50 % of the total iron in the Grassland site and 27 - 44 % in the Oxbow site. Correspondingly, least squares fitting of k3 - weighted chi(k) iron extended X-ray absorption fine structure (EXAFS) spectra showed that goethite and hematite together comprised 34 - 50 % of the iron mineralogy in the mineral sediments of the Grassland site and 24 - 38 % of those in the Oxbow site. The remaining iron minerals present were predominantly silicates. Iron EXAFS spectra were obtained for the post-CBD extracted sediments, theoretically containing only non-reducible iron. Least squares fitting of the bulk (pre-CBD extracted) sediments was performed a second time with the

  14. Greater Mekong Sub-region Options for the Structure of the GMS Power Trade Market : A First Overview of Issues and Possible Options

    OpenAIRE

    World Bank

    2006-01-01

    The World Bank, working together with the Asian Development Bank (ADB), actively supports the development of a regional power market in the GMS: Cambodia, Lao PDR, Myanmar, Thailand, Vietnam and the Yunnan Province of the People's Republic of China. This report is part of a dynamic process aimed at developing power trade in the Greater Mekong Sub-region (GMS), the objective of which will ...

  15. Copper toxicity and the influence of water quality of Dongnai River and Mekong River waters on copper bioavailability and toxicity to three tropical species.

    Science.gov (United States)

    Bui, Thanh-Khiet L; Do-Hong, L Chi; Dao, Thanh-Son; Hoang, Tham C

    2016-02-01

    The present study investigated copper (Cu) toxicity and the influence of water quality characteristics of Dongnai River and Mekong River (Vietnam) surface waters to three tropical species; Daphnia lumholtzi, Ceriodaphnia cornuta, and Danio rerio. The river waters had a range of water quality parameters that modify Cu bioavailability and toxicity. The range of total hardness, alkalinity, pH and dissolved organic carbon were 15-64 mg/L as CaCO3, 18-58 mg/L as CaCO3, 6.62-7.88, and 6.9-14.7 mg/l, respectively. The US EPA acute toxicity test method with a modification to the light photoperiod and temperature for tropical organisms was used to investigate Cu toxicity. Result of the present study found that Cu produced toxic effect to the studied organisms at low concentrations. The 48-h LC50 ranged from 3.92 to 8.61 µg/l, 2.92-9.56 µg/l, and 15.71-68.69 µg/l dissolved Cu for D. lumholtzi, C. cornuta, and D. rerio, respectively. In general, water quality had an influence on Cu bioavailability and toxicity to the studied organisms. The toxicity of Cu was higher in water with lower hardness, DOC, and/or pH. The present study indicates a contribution of Cu hydroxide and carbonate to Cu bioavailability to Mekong organisms. Results of the present study will be used for calibrating the US Cu Biotic Ligand Model (BLM) to Mekong River water and organisms in support of application of the BLM for setting site-specific Cu water quality guidelines in the ecosystem of the Lower Mekong River Basin.

  16. Mapping wetlands in the Lower Mekong Basin for wetland resource and conservation management using Landsat ETM images and field survey data.

    Science.gov (United States)

    MacAlister, Charlotte; Mahaxay, Manithaphone

    2009-05-01

    The Mekong River Basin is considered to be the second most species rich river basin in the world. The 795,000 km(2) catchment encompasses several ecoregions, incorporating biodiverse and productive wetland systems. Eighty percent of the rapidly expanding population of the Lower Mekong Basin (LMB), made up in part by Lao PDR, Thailand, Cambodia and Viet Nam, live in rural areas and are heavily reliant on wetland resources. As the populations of Cambodia and Lao PDR will double in the next 20 years, pressure on natural resources and particularly wetlands can only increase. For development planning, resource and conservation management to incorporate wetland issues, information on the distribution and character of Mekong wetlands is essential. The existing but outdated wetland maps were compiled from secondary landuse-landcover data, have limited coverage, poor thematic accuracy and no meta-data. Therefore the Mekong River Commission (MRC) undertook to produce new wetland coverage for the LMB. As resources, funding and regional capacity are limited, it was determined that the method applied should use existing facilities, be easily adaptable, and replicable locally. For the product to be useful it must be accepted by local governments and decision makers. The results must be of acceptable accuracy (>75%) and the methodology should be relatively understandable to non-experts. In the first stage of this exercise, field survey was conducted at five pilot sites covering a range of typical wetland habitats (MRC wetland classification) to supply data for a supervised classification of Landsat ETM images from the existing MRC archive. Images were analysed using ERDAS IMAGINE and applying Maximum Likelihood Classification. Field data were reserved to apply formal accuracy assessment to the final wetland habitat maps, with resulting accuracy ranging from 77 to 94%. The maps produced are now in use at a Provincial and National level in three countries for resource and

  17. International Cooperation Problems in the Environmental Protection of Mekong%湄公河环境保护国际合作问题研究

    Institute of Scientific and Technical Information of China (English)

    龙悦宁

    2014-01-01

    湄公河是一条跨越中国、老挝、缅甸、泰国、柬埔寨和越南六国的国际河流。国际河流的利用和开发是中国在面向次湄公河区域合作过程中不可避免要面对的问题和迎接的挑战。本文通过对国际河流利用中,中国同下游国家进行环境保护国际合作的必要性、湄公河利用与环境保护现状及问题的阐述,提出了应当建立湄公河开发、生态保护与航运贸易相结合的管理规划模式、与相邻国家在国内外环境保护与水利开发增加互动的国际合作并明确相应的国际责任的建议。%Mekong is a international river that crosses six countries of China, Laos, Myanmar, Thailand, Cambodia and Vietnam. Development and utilization of international rivers are the problems and challenges for China which will inevitably face and greet in the Mekong sub-regional cooperation process. Through elaborating the necessity of international cooperation in environmental protection for China and the downstream countries, the use, environmental protection situations and problems of Mekong in the utilization of international rivers, this paper proposes that the management planning mode of combining Mekong development, ecological protection and shipping trade should be established, the international cooperation of environmental protection at home and abroad and water conservancy development with neighboring countries should be increased and the international responsibilities should be cleared.

  18. Climate change and agricultural transformation in the Oaxaca Valley, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Dilley, F.B.

    1993-01-01

    The Valley of Oaxaca, a semi-arid region in the central highlands of southern Mexico, provides a case study through which to develop a methodology for climate change impact assessment. The causes and impacts of climate change originate in dialectic processes within a nexus of inter-dependent social, technical, environmental, cultural and academic production relations. Agriculture is the most important economic activity in the Valley, and rain-fed maize the most important crop. Harvest failures from droughts occur one year in four. Annual rainfall varies with large-scale convection of water vapor transported from the Pacific and Gulf of Mexico during summer, upper-air disturbances caused by hurricanes and El Ninos. Variations in maize yields and losses have roughly moisture availability during August. Yields and losses can be predicted using precipitation during this time, or directly from atmospheric circulation. Contemporary agriculture in the Valley of Oaxaca has both traditional and modern sectors, of which both may appear within individual communities and households. The traditional sector consists of semi-autonomous rural communities using traditional technology for subsistence farming. The modern sector uses tractors, irrigation pumps, agricultural chemicals and hybrid seeds to produce cash crops and dairy products. The evidence for climate change in the Valley is ambiguous and contradictory. Under wet or dry scenarios, climate change affects the rate and pathway of the absorption of Oaxaca's traditional rural communities into the wage labor market of the larger capitalist system. Increased moisture availability would raise land productivity, promoting cash cropping and development of the modern market-oriented agricultural sector and leading to land consolidation and rural-to-urban migration. Decreased moisture availability would inhibit cash-cropping but also lead to rural-to-urban migration due to decreased land productivity.

  19. Mapping Ecosystem Services in the Jordan Valley, Jordan

    Science.gov (United States)

    Luz, Ana; Marques, Ana; Ribeiro, Inês; Alho, Maria; Catarina Afonso, Ana; Almeida, Erika; Branquinho, Cristina; Talozi, Samer; Pinho, Pedro

    2016-04-01

    In the last decade researchers started using ecosystem services as a new framework to understand the relationships between environment and society. Habitat quality and water quality are related with ecosystem services regulation and maintenance, or even provision. According to the Common International Classification of Ecosystem Services (CICES) both habitat quality and water quality are associated with lifecycle maintenance, habitat and gene pool protection, and water conditions, among others. As there is increased pressure on habitats and rivers especially for agricultural development, mapping and evaluating habitat and water quality has important implications for resource management and conservation, as well as for rural development. Here, we model and map habitat and water quality in the Jordan Valley, Jordan. In this study, we aim to identify and analyse ecosystem services both through 1) habitat quality and 2) water quality modelling using InVest, an integrated valuation of ecosystem services and tradeoffs. The data used in this study mainly includes the LULC, Jordan River watershed and main threats and pollutants in the study area, such as agriculture, industry, fish farms and urbanization. Results suggest a higher pressure on natural habitats in the Northern region of the Jordan Valley, where industry is dominant. Agriculture is present along the Jordan Valley and limits the few natural forested areas. Further, water pollution is mainly concentrated in disposal sites due to the low flow of the Jordan River. Our results can help to identify areas where natural resources and water resource management is most needed in the Jordan Valley. Acknowledgements: Transbasin FP7 project

  20. Valley blockade quantum switching in Silicon nanostructures.

    Science.gov (United States)

    Prati, Enrico

    2011-10-01

    In analogy to the Coulomb and the Pauli spin blockade, based on the electrostatic repulsion and the Pauli exclusion principle respectively, the concept of valley blockade in Silicon nanostructures is explored. The valley parity operator is defined. Valley blockade is determined by the parity conservation of valley composition eigenvectors in quantum transport. A Silicon quantum changeover switch based on a triple of donor quantum dots capable to separate electrons having opposite valley parity by virtue of the valley parity conservation is proposed. The quantum changeover switch represents a novel kind of hybrid quantum based classical logic device.

  1. Potential effects of hydroelectric dam development in the Mekong River basin on the migration of Siamese mud carp (Henicorhynchus siamensis and H. lobatus elucidated by otolith microchemistry.

    Directory of Open Access Journals (Sweden)

    Michio Fukushima

    Full Text Available The migration of Siamese mud carp (Henicorhynchus siamensis and H. lobatus, two of the most economically important fish species in the Mekong River, was studied using an otolith microchemistry technique. Fish and river water samples were collected in seven regions throughout the whole basin in Thailand, Laos and Cambodia over a 4 year study period. There was coherence between the elements in the ambient water and on the surface of the otoliths, with strontium (Sr and barium (Ba showing the strongest correlation. The partition coefficients were 0.409-0.496 for Sr and 0.055 for Ba. Otolith Sr-Ba profiles indicated extensive synchronized migrations with similar natal origins among individuals within the same region. H. siamensis movement has been severely suppressed in a tributary system where a series of irrigation dams has blocked their migration. H. lobatus collected both below and above the Khone Falls in the mainstream Mekong exhibited statistically different otolith surface elemental signatures but similar core elemental signatures. This result suggests a population originating from a single natal origin but bypassing the waterfalls through a passable side channel where a major hydroelectric dam is planned. The potential effects of damming in the Mekong River are discussed.

  2. A hydrological model for interprovincial water resource planning and management: A case study in the Long Xuyen Quadrangle, Mekong Delta, Vietnam

    Science.gov (United States)

    Hanington, Peter; To, Quang Toan; Van, Pham Dang Tri; Doan, Ngoc Anh Vu; Kiem, Anthony S.

    2017-04-01

    In this paper we present the results of the development and calibration of a fine-scaled quasi-2D hydrodynamic model (IWRM-LXQ) for the Long Xuyen Quadrangle - an important interprovincial agricultural region in the Vietnamese Mekong Delta. We use the Long Xuyen Quadrangle as a case study to highlight the need for further investment in hydrodynamic modelling at scales relevant to the decisions facing water resource managers and planners in the Vietnamese Mekong Delta. The IWRM-LXQ was calibrated using existing data from a low flood year (2010) and high flood year (2011), including dry season and wet season flows. The model performed well in simulating low flood and high flood events in both dry and wet seasons where good spatial and temporal data exists. However, our study shows that there are data quality issues and key data gaps that need to be addressed before the model can be further refined, validated and then used for decision making. The development of the IWRM-LXQ is timely, as significant investments in land and water resource development and infrastructure are in planning for the Vietnamese Mekong Delta. In order to define the scope of such investments and their feasibility, models such as the IWRM-LXQ are an essential tool to provide objective assessment of investment options and build stakeholder consensus around potentially contentious development decisions.

  3. Large Dams and Changes in an Agrarian Society: Gendering the Impacts of Damodar Valley Corporation in Eastern India

    Directory of Open Access Journals (Sweden)

    Kuntala Lahiri-Dutt

    2012-06-01

    Full Text Available This paper traces the gendered changes in agrarian livelihoods in the lower Damodar valley of eastern India and connects these changes to the large dam project of the Damodar Valley Corporation (DVC. The DVC, established in 1948, was one of the earliest dam projects in India. Although it was not fully completed, the DVC project has initiated unforeseen changes in the farming economy. The floods for which the Damodar river was notorious were not fully controlled, and the suffering of people living in the lower reaches of the valley never really diminished. This paper gives a brief description of the river and its history of water management practices and the roles of women and men in these practices. It traces the resultant impacts on gender roles, and outlines the new kinds of water management that emerged in response to the DVC’s failure to provide irrigation water when demanded. More specifically, the paper explores the changes in floods, changes in the farming economy, and the impacts of temporary sand dams or boro bandhs on the livelihoods of women and men from farming families in the Lower Damodar Valley. It observes that even over a longer temporal scale, the changes unleashed by large water control projects have significant and gendered impacts on agrarian societies.

  4. Livestock Farming Under Climate Change Conditions

    CSIR Research Space (South Africa)

    Koelle, B

    2016-12-01

    Full Text Available for livestock farming under changing environmental conditions. Farming with livestock can be challenging, especially when farming in arid areas. This handbook is primarily informed by the experience of farmers in the South African winter rainfall area....

  5. Strategy and risk in farming

    OpenAIRE

    Huirne, R.B.M.

    2002-01-01

    Issues that are relevant in current farm management are discussed. First, three basic farm management theories are presented: (1) decision-making theory; (1) system theory; and (3) theory of management by objectives. Next, two new developments are introduced, namely, strategic management and risk management.

  6. Intelligent control on wind farm

    DEFF Research Database (Denmark)

    Wei, Mu; Chen, Zhe

    2010-01-01

    with the wind farm makes the grid more vulnerable. The communication technologies have been considered as a solution to solve the problems according to the IEC 61400-25 series protocols. This paper presents the significance of communication technologies in wind farm system by the simulations on some practical...

  7. Grieving for the Family Farm.

    Science.gov (United States)

    Zeller, Simon H.

    1986-01-01

    Reviews impact of recent agricultural trends in South Dakota. Outlines Kubler-Ross' stages of grief/adaptation that farm families must negotiate as they cope with the trauma of the loss of their farms. Indicates service providers must overcome farmers' mistrust for human welfare services and reach out to this vulnerable population. (NEC)

  8. Food and farm products surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the radiological analyses performed on food and farm samples collected during 1994. The food and farm sampling design addresses the potential influence of Hanford Site releases. Details of the sampling design and radionuclides analyzed are included in this section.

  9. Offshore wind farms: Danish experiences

    Energy Technology Data Exchange (ETDEWEB)

    Gravesen, H.; Taylor, D.; Petersen, A. [Carl Bro Group, Edinburgh (United Kingdom)

    2000-07-01

    Denmark has extensive plans for offshore wind farms, and by 2030 parks to generate some 5,500 MW of power will be constructed. Out of this 4,000 MW will be offshore and to date 15 sites have been identified. Carl Bro Group are currently involved in the programme carrying out basic and detailed design, including EIA for 5 sites where construction is planned to take place before 2005. The first phase consists of the installation of 150MW wind farms. In Middelgrunden, off shore from Copenhagen, a scheme is well advanced to install 20 windmills generating approximately 40MW of power. This project is the largest offshore wind farm in the world and illustrates Denmark's commitment to sustainability. The paper gives an overview of the plans for offshore wind farms in Denmark and includes a detailed description of the farm at Middelgrunden, with emphasis on environmental, aesthetic, safety, design, construction and installation aspects. (Author)

  10. TOPFARM wind farm optimization tool

    DEFF Research Database (Denmark)

    Réthoré, Pierre-Elouan; Fuglsang, Peter; Larsen, Torben J.;

    the optimization problem includes elements as energy production, turbine degradation, operation and maintenance costs, electrical grid costs and foundation costs. The objective function is optimized using a dedicated multi fidelity approach with the locations of individual turbines in the wind farm spanning......A wind farm optimization framework is presented in detail and demonstrated on two test cases: 1) Middelgrunden and 2) Stags Holt/Coldham. A detailed flow model describing the instationary flow within a wind farm is used together with an aeroelastic model to determine production and fatigue loading...... of wind farm wind turbines. Based on generic load cases, the wind farm production and fatigue evaluations are subsequently condensed in a large pre-calculated database for rapid calculation of lifetime equivalent loads and energy production in the optimization loop.. The objective function defining...

  11. Characteristics of New Jersey Agritourism Farms

    OpenAIRE

    Schilling, Brian J.; Sullivan, Kevin P.

    2014-01-01

    Agritourism is an important alternative farm enterprise strategy in the U.S., especially for farms operating under urban influence. This paper develops a logit model to identify the characteristics of farms engaged in agritourism using 2007 Census of Agriculture respondent-level records. New Jersey, which ranks first nationally in the proportion of farm income derived from agritourism, provides the geographic context. We find that fruit/vegetable farms, rural residential/retirement farms, and...

  12. Modelling photochemistry in alpine valleys

    Directory of Open Access Journals (Sweden)

    G. Brulfert

    2005-01-01

    Full Text Available Road traffic is a serious problem in the Chamonix Valley, France: traffic, noise and above all air pollution worry the inhabitants. The big fire in the Mont-Blanc tunnel made it possible, in the framework of the POVA project (POllution in Alpine Valleys, to undertake measurement campaigns with and without heavy-vehicle traffic through the Chamonix and Maurienne valleys, towards Italy (before and after the tunnel re-opening. Modelling is one of the aspects of POVA and should make it possible to explain the processes leading to episodes of atmospheric pollution, both in summer and in winter. Atmospheric prediction model ARPS 4.5.2 (Advanced Regional Prediction System, developed at the CAPS (Center for Analysis and Prediction of Storms of the University of Oklahoma, enables to resolve the dynamics above a complex terrain. This model is coupled to the TAPOM 1.5.2 atmospheric chemistry (Transport and Air POllution Model code developed at the Air and Soil Pollution Laboratory of the Ecole Polytechnique Fédérale de Lausanne. The numerical codes MM5 and CHIMERE are used to compute large scale boundary forcing. This paper focuses on modelling Chamonix valley using 300-m grid cells to calculate the dynamics and the reactive chemistry which makes possible to accurately represent the dynamics in the Chamonix valley (slope and valley winds and to process chemistry at fine scale. The summer 2003 intensive campaign was used to validate the model and to study chemistry. NOy according to O3 reduction demonstrates a VOC controlled regime, different from the NOx controlled regime expected and observed in the nearby city of Grenoble.

  13. Modelling photochemistry in alpine valleys

    Directory of Open Access Journals (Sweden)

    G. Brulfert

    2005-03-01

    Full Text Available Road traffic is a serious problem in the Chamonix Valley, France: traffic, noise and above all air pollution worry the inhabitants. The big fire in the Mont-Blanc tunnel made it possible, in the framework of the POVA project (POllution in Alpine Valleys, to undertake measurement campaigns with and without heavy-vehicle traffic through the valley, towards Italy (before and after the tunnel re-opening. Modelling in POVA should make it possible to explain the processes leading to episodes of atmospheric pollution, both in summer and in winter.

    Atmospheric prediction model ARPS 4.5.2 (Advanced Regional Prediction System, developed at the CAPS (Center for Analysis and Prediction of Storms of the University of Oklahoma, enables to resolve the dynamics above a complex terrain.

    This model is coupled to the TAPOM 1.5.2 atmospheric chemistry (Transport and Air POllution Model code developed at the Air and Soil Pollution Laboratory of the Ecole Polytechnique Fédérale de Lausanne.

    The numerical codes MM5 and CHIMERE are used to compute large scale boundary forcing.

    Using 300-m grid cells to calculate the dynamics and the reactive chemistry makes possible to accurately represent the dynamics in the valley (slope and valley winds and to process chemistry at fine scale.

    Validation of campaign days allows to study chemistry indicators in the valley. NOy according to O3 reduction demonstrates a VOC controlled regime, different from the NOx controlled regime expected and observed in the nearby city of Grenoble.

  14. Wind Farm Control Survey

    DEFF Research Database (Denmark)

    Knudsen, Torben; Bak, Thomas; Svenstrup, Mikael

    2013-01-01

    This document is a delivery in the project NORCOWE. It is part of work package WP3.2.2. The main goal is to establish the present state-of-the-art for wind farm control for both research and practice. The main approach will be to study the literature. This will of cause be much more efficient...... for the research part than for the practice part. It is however not the intention to do company interviews or similar. This report is structured into a section for each WF control objective. These sections then includes the important control project issues: choice of input and output, control method, and modelling...... used for controller design and simulation respectively. A short section then discusses published literature from industry. Finally a conclusion is given discussing established results, open challenges and necessary research. An appendix present a method for optimising the energy in a one row wind...

  15. Biomass plantations - energy farming

    Energy Technology Data Exchange (ETDEWEB)

    Paul, S.

    1981-02-01

    Mounting oil import bills in India are restricting her development programmes by forcing the cutting down of the import of other essential items. But the countries of the tropics have abundant sunlight and vast tracts of arable wastelands. Energy farming is proposed in the shape of energy plantations through forestry or energy cropping through agricultural media, to provide power fuels for transport and the industries and also to provide fuelwoods for the domestic sector. Short rotation cultivation is discussed and results are given of two main species that are being tried, ipil-ipil and Casuarina. Evaluations are made on the use of various crops such as sugar cane, cassava and kenaf as fuel crops together with hydrocarbon plants and aquatic biomass. (Refs. 20)

  16. Small Glaciofluvial Valleys on Amazonian Mars

    Science.gov (United States)

    Fassett, C.; Dickson, J.; Head, J. W.; Levy, J. S.; Marchant, D. R.

    2009-12-01

    We present new observations of small valleys associated with glacial features in the Martian mid-latitudes, based on a survey of images from the Context Camera (CTX) on the Mars Reconnaissance Orbiter. These valleys are small (~50-400 m wide) and short (mechanism most likely to explain their origin is top-down melting of these cold-based glaciers. Some valleys have associated sedimentary deposits (small fans) (e.g., Fig. 1). Both stratigraphic relations and crater counting constrain most such valleys to the Amazonian period. The observed glaciofluvial valleys are typically on slopes of P16_007256_1383). The valley begins in a small alcove, where remnant glacial materials are now ~1 km from the valley head. The valley is ~5.5 km long, has an average slope of 5°, and terminates in an elongate fan.

  17. EPA Region 1 - Valley Depth in Meters

    Data.gov (United States)

    U.S. Environmental Protection Agency — Raster of the Depth in meters of EPA-delimited Valleys in Region 1. Valleys (areas that are lower than their neighbors) were extracted from a Digital Elevation Model...

  18. Valley evolution by meandering rivers

    Science.gov (United States)

    Limaye, Ajay Brian Sanjay

    Fluvial systems form landscapes and sedimentary deposits with a rich hierarchy of structures that extend from grain- to valley scale. Large-scale pattern formation in fluvial systems is commonly attributed to forcing by external factors, including climate change, tectonic uplift, and sea-level change. Yet over geologic timescales, rivers may also develop large-scale erosional and depositional patterns that do not bear on environmental history. This dissertation uses a combination of numerical modeling and topographic analysis to identify and quantify patterns in river valleys that form as a consequence of river meandering alone, under constant external forcing. Chapter 2 identifies a numerical artifact in existing, grid-based models that represent the co-evolution of river channel migration and bank strength over geologic timescales. A new, vector-based technique for bank-material tracking is shown to improve predictions for the evolution of meander belts, floodplains, sedimentary deposits formed by aggrading channels, and bedrock river valleys, particularly when spatial contrasts in bank strength are strong. Chapters 3 and 4 apply this numerical technique to establishing valley topography formed by a vertically incising, meandering river subject to constant external forcing---which should serve as the null hypothesis for valley evolution. In Chapter 3, this scenario is shown to explain a variety of common bedrock river valley types and smaller-scale features within them---including entrenched channels, long-wavelength, arcuate scars in valley walls, and bedrock-cored river terraces. Chapter 4 describes the age and geometric statistics of river terraces formed by meandering with constant external forcing, and compares them to terraces in natural river valleys. The frequency of intrinsic terrace formation by meandering is shown to reflect a characteristic relief-generation timescale, and terrace length is identified as a key criterion for distinguishing these

  19. 27 CFR 9.57 - Green Valley of Russian River Valley.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Green Valley of Russian River Valley. 9.57 Section 9.57 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE... Areas § 9.57 Green Valley of Russian River Valley. (a) Name. The name of the viticultural area...

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

    Directory of Open Access Journals (Sweden)

    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.

  1. 27 CFR 9.154 - Chiles Valley.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Chiles Valley. 9.154... Chiles Valley. (a) Name. The name of the viticultural area described in this section is “Chiles Valley.” (b) Approved maps. The appropriate maps for determining the boundary of the Chiles...

  2. 27 CFR 9.23 - Napa Valley.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Napa Valley. 9.23 Section... THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.23 Napa Valley. (a) Name. The name of the viticultural area described in this section is “Napa Valley.”...

  3. Valley Singularities and Baryon Number Violation

    CERN Document Server

    Provero, P

    1994-01-01

    We consider the valley--method computation of the inclusive cross section of baryon number violating processes in the Standard Model. We show that any physically correct model of the valley action should present a singularity in the saddle point valley parameters as functions of the energy of the process. This singularity prevents the saddle point configuration from collapsing into the perturbative vacuum.

  4. 澜沧江-湄公河合作机制与跨境安全治理%The Lancang-Mekong Cooperation Framework and Transboundary Security Governance

    Institute of Scientific and Technical Information of China (English)

    卢光盛; 张励

    2016-01-01

    跨境安全问题是影响中国与缅甸、泰国、老挝、柬埔寨、越南5个下湄公河国家政治经济合作的关键因素,同时也是关系澜沧江—湄公河次区域合作水平能否冲破瓶颈的重要条件。现有的大湄公河次区域经济合作、东盟—湄公河流域开发合作机制、湄公河委员会等多边机制对于跨境安全问题捉襟见肘、应对不力。2015年11月中国提出的澜沧江—湄公河合作机制正式建立,其合作内容涵盖政治安全、经济和可持续发展、社会人文3个重点领域。因此,该机制的建立为解决次区域内跨界安全问题、深化区域合作提供了新的机遇,也为中国展现其国际秩序建设能力提供了新的平台和渠道。本文先就澜沧江—湄公河合作机制下跨境安全治理的相关概念、研究现状进行分析,接着探讨澜沧江—湄公河次区域内的跨境安全问题、根源与影响,最后指出通过夯实中国与下湄公河国家的互信基础,构建跨境安全治理的合作平台,发挥中国在跨境安全治理中的建设性作用,发挥次国家政府的能动作用,处理好与域外国家和其他合作机制的竞合关系,开展跨境安全治理的早期收获等路径来发挥澜沧江—湄公河机制的跨境安全治理作用,有效应对澜沧江—湄公河次区域的跨境安全问题。%The transboundary security issues are the key to the political and economic cooperation between China and the Lower Mekong Countries, namely, Myanmar, Thailand, Laos, Cambodia and Vietnam. They are also fundamental for breaking bottleneck in the level of cooperation in the Lanccang-Mekong subregion. These existing the Great Mekong Subre-gion Economic Cooperation, ASEAN Mekong Basin Development Cooperation and the Mekong River Commission cannot be powerful enough when dealing with the transboundary security issues. The Lancang-Mekong Cooperation Framework came up with by

  5. The Future of Silicon Valley

    Institute of Scientific and Technical Information of China (English)

    Joseph Leu

    2006-01-01

    @@ By the end of 1984, Silicon Valley was going through the down cycle fol lowing the PC boom. A hundred PC companies wanted just 10 percent of the market, wanting to strike it rich, as rich as the Apple IPO (Initial Public Of fering) -the Google celebrity IPO of its day.

  6. Atmospheric turbidity over Kathmandu valley

    Science.gov (United States)

    Sapkota, Balkrishna; Dhaubhadel, Rajan

    The atmosphere of Kathmandu Valley has been investigated by using Sunphotometer and Nephelometer during the pre-monsoon period of 1999. The atmospheric turbidity parameters (extinction coefficient for 500 nm wavelength τAG and Angstrom coefficient β) are found high in the morning and show decreasing trends from morning to late afternoon on average. Vertical dispersion of pollutants and increasing pollutant flushing rate by increasing wind speed from morning to late afternoon is the cause for this decreasing trend of turbidity over the valley. Being surrounded by high hills all around the valley, horizontal exit of pollutants without vertical dispersion is not possible. The scattering coefficient bscat of aerosols in ground level troposphere is also found high in the morning, which decreases and becomes minimum during afternoon. During late afternoon, bscat again shows a slightly increasing trend. The reason is the increasing vehicular emission during late afternoon rush period. The average values of Angstrom exponent α, β, τAG and bscat are found to be 0.624±0.023, 0.299±0.009, 0.602±0.022 and 0.353±0.014 km -1, respectively. About 76.8% of the observed values of β lie above 0.2 indicating heavy particulate pollution in the valley. A comparison of observed values of turbidity parameters with other major cities of the world shows that Kathmandu is as polluted as cities like Jakarta, Kansas, Beijing, Vienna, etc.

  7. CDF II production farm project

    Energy Technology Data Exchange (ETDEWEB)

    Baranovski, A.; Benjamin, D.; Cooper, G.; Farrington, S.; Genser, K.; Hou, S.; Hsieh, T.; Kotwal, A.; Lipeles, E.; Murat, P.; Norman, M.; /Fermilab /Duke U. /Taiwan,

    2006-12-01

    We describe the architecture and discuss our operational experience in running the off-line reconstruction farm of the CDFII experiment. The Linux PC-based farm performs a wide set of tasks,ranging from producing calibrations and primary event reconstruction to large scale ntuple production.The farm control software uses a standard Condor toolkit and the data handling part is based on SAM (Sequential Access via Metadata)software.During its lifetime,the CDFII experiment will integrate a large amount of data (several petabytes)and the data processing chain is one of the key components of the successful physics program of the experiment.

  8. HIV voluntary testing and perceived risk among female sex workers in the Mekong Delta region of Vietnam

    Directory of Open Access Journals (Sweden)

    Bach Xuan Tran

    2013-07-01

    Full Text Available Introduction: HIV voluntary counseling and testing (VCT comprise an effective preventive measure and an entry point to care and support services. We sought to assess VCT uptake and HIV-related knowledge and perceived risk among female sex workers (FSWs in five provinces of the Mekong Delta region. Methods: A cross-sectional survey was carried out in 1998 FSWs, including both street-based sex workers (SSWs and entertainment-based sex workers (ESWs. Results: High proportions of FSWs were aware that using condoms (94.6%, and clean needles (34.1% are preventive measures that reduce the risk of HIV transmission. Some FSWs reported avoiding public toilet use (8.6%, physical contacts (16.1%, or sharing meals (10.9% with people living with HIV/AIDS, and preventing mosquito bites (20.8%. Twenty-nine percent (29.0% of FSWs perceived themselves as being at risk of HIV infection. Only 32.7% had ever tested for HIV, of whom 54% were voluntary for testing. FSWs who ever injected drugs (OR = 0.03, p=0.05, had drug-injecting clients (OR = 0.07, p<0.01, and had inconsistent condom use with husbands or lovers (OR = 0.10, p=0.01 were less likely to have a voluntary test. Inconsistent condom use with clients (OR = 13.86, p<0.01, and receiving HIV information from radio (OR = 13.28, p<0.05 and communication campaigns (OR = 6.69, p<0.05, increased the likelihood of VCT uptake. Conclusion: Inadequate knowledge and some misconceptions about HIV transmission routes and preventive measures, low perceived risk of HIV infection, and low VCT uptake were observed among FSWs in the Mekong Delta region. Interventions to improve their knowledge and self-efficacy, reduce risky behaviors, and encourage VCT uptake and early access to health care services are necessary to prevent HIV transmission in this region.

  9. Initiation of the Mekong River delta at 8 ka: evidence from the sedimentary succession in the Cambodian lowland

    Science.gov (United States)

    Tamura, Toru; Saito, Yoshiki; Sieng, Sotham; Ben, Bunnarin; Kong, Meng; Sim, Im; Choup, Sokuntheara; Akiba, Fumio

    2009-02-01

    Modern deltas are understood to have initiated around 7.5-9 ka in response to the deceleration of sea-level rise. This episode of delta initiation is closely related to the last deglacial meltwater events and eustatic sea-level rises. The initial stage of the Mekong River delta, one of the world's largest deltas, is well recorded in Cambodian lowland sediments. This paper integrates analyses of sedimentary facies, diatom assemblages, and radiocarbon dates for three drill cores from the lowland to demonstrate Holocene sedimentary evolution in relation to sea-level changes. The cores are characterized by a tripartite succession: (1) aggrading flood plain to natural levee and tidal-fluvial channel during the postglacial sea-level rise (10-8.4 ka); (2) aggrading to prograding tidal flats and mangrove forests around and after the maximum flooding of the sea (8.4-6.3 ka); and (3) a prograding fluvial system on the delta plain (6.3 ka to the present). The maximum flooding of the sea occurred at 8.0 ± 0.1 ka, 2000 years before the mid-Holocene sea-level highstand, and tidal flats penetrated up to 20-50 km southeast of Phnom Penh after a period of abrupt ˜5 m sea-level rise at 8.5-8.4 ka. The delta progradation then initiated as a result of the sea-level stillstand at around 8-7.5 ka. Another rapid sea-level rise at 7.5-7 ka allowed thick mangrove peat to be widely deposited in the Cambodian lowland, and the peat accumulation endured until 6.3 ka. Since 6.3 ka, a fluvial system has characterized the delta plain, and the fluvial sediment discharge has contributed to rapid delta progradation. The uppermost part of the sedimentary succession, composed of flood plain to natural-levee sediments, reveals a sudden increase in sediment accumulation over the past 600-1000 years. This increase might reflect an increase in the sediment yield due to human activities in the upper to middle reaches of the Mekong, as with other Asian rivers.

  10. Discrimination rice cropping systems using multi-temporal Proba-V data in the Mekong Delta, Vietnam

    Science.gov (United States)

    Son, Nguyen-Thanh; Chen, Chi-Farn; Chen, Cheng-Ru; Chang, Ly-Yu; Chiang, Shou-Hao; Lau, Khin-Va

    2016-04-01

    Rice is considered a main source of livelihoods for several billions of people worldwide and plays an important role in the economy of many Asian countries. More than just a food source, rice production is regarded as one of the most important components to maintaining political stability and is also a national subject of economic policy due to domestic food consumption and grain exports. Vietnam is globally one of the largest rice producers and suppliers with more than 80% of the exported rice amount produced from the Mekong River Delta. This delta is one of the three deltas in the world most vulnerable to the climate change, causing the potential loss of rice yields. Thus, spatiotemporal information of rice cropping systems is important for agricultural management to ensure food security and rice grain exports. Coarse resolution satellite data such as MODIS demonstrates the applicability for rice mapping at a large scale. However, the use of MODIS data for such a monitoring purpose still reveals a challenging task due to mixed-pixel issues. The Proba-V satellite launched on 7 May 2013 is a potential candidate for this monitoring purpose because the data include four spectral bands (blue, red, near-infrared and mid-infrared) with a swath of 2,285 km with a spatial resolution of 100 m and temporal resolution of 5 days. This study aimed to investigate the applicability of multi-temporal Proba-V data for mapping rice cropping systems in Mekong Delta River, South Vietnam. The data were processed for 2014-2015 rice cropping seasons, following three main steps: (1) construction of smooth time-series NDVI data, (2) classification of rice cropping systems using crop phenological metrics, and (3) accuracy assessment of the mapping results. The results indicated that the smooth time-series NDVI profiles characterized the temporal spectral responses of rice fields through different growing stages of rice plant, which was critically important for understanding rice crop

  11. Three-fold embeddedness of farm development

    NARCIS (Netherlands)

    Methorst, R.G.; Roep, D.; Verstegen, J.A.A.M.

    2016-01-01

    Farm development strategy is affected by, and affects, the biophysical and socio-economic context of the farm leading to agri-environmental challenges for farm development. For effective policies and support programmes it is important to understand the drivers for choices farm development. Three-fol

  12. Planning farm succession: how to be successful

    OpenAIRE

    Stephens, Mike

    2011-01-01

    Planning farm succession is really good farm planning in its broadest aspect. Unfortunately very few farmers and their families have devoted sufficient time to working out how the farm business will be transferred. After demonstrating the importance of the farm succession issue, this article goes on to explaining a method of successfully tackling the process.

  13. Organic Farming, Gender, and the Labor Process

    Science.gov (United States)

    Hall, Alan; Mogyorody, Veronika

    2007-01-01

    This paper seeks to explain variations in gender participation in farm production and decision-making through an analysis of organic farm types, sizes, and orientations. Based on both survey and case study data, the analysis shows that female farmers on vegetable farms and mixed livestock/cash crop farms are more likely to be involved in farm…

  14. 7 CFR 718.201 - Farm constitution.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Farm constitution. 718.201 Section 718.201 Agriculture... Reconstitution of Farms, Allotments, Quotas, and Bases § 718.201 Farm constitution. (a) In order to implement... this section. The constitution and identification of land as a farm for the first time and...

  15. Nature Quality in Organic Farming

    DEFF Research Database (Denmark)

    Tybirk, Knud; Alrøe, Hugo; Frederiksen, Pia

    2004-01-01

    Nature quality in relation to farming is a complex field. It involves different traditions and interests, different views of what nature is, and different ways of valuing nature. Furthermore there is a general lack of empirical data on many aspects of nature quality in the farmed landscape....... In this paper we discuss nature quality from the perspective of organic farming, which has its own values and goals in relation to nature – the Ecologist View of Nature. This is in contrast to the Culturist View characteristic of much conventional agriculture and the Naturalist View characteristic...... of the traditional biological approach to nature quality. This threefold distinction forms a framework for exploration of nature quality criteria in the farmed landscape. The traditional work on nature quality has mainly focused on biological interests based on a Naturalist View of Nature. In this paper we...

  16. Push-pull farming systems.

    Science.gov (United States)

    Pickett, John A; Woodcock, Christine M; Midega, Charles A O; Khan, Zeyaur R

    2014-04-01

    Farming systems for pest control, based on the stimulo-deterrent diversionary strategy or push-pull system, have become an important target for sustainable intensification of food production. A prominent example is push-pull developed in sub-Saharan Africa using a combination of companion plants delivering semiochemicals, as plant secondary metabolites, for smallholder farming cereal production, initially against lepidopterous stem borers. Opportunities are being developed for other regions and farming ecosystems. New semiochemical tools and delivery systems, including GM, are being incorporated to exploit further opportunities for mainstream arable farming systems. By delivering the push and pull effects as secondary metabolites, for example, (E)-4,8-dimethyl-1,3,7-nonatriene repelling pests and attracting beneficial insects, problems of high volatility and instability are overcome and compounds are produced when and where required.

  17. Green Care Farms

    Directory of Open Access Journals (Sweden)

    Simone R. de Bruin PhD

    2015-10-01

    Full Text Available Objective: To explore the value of day services at green care farms (GCFs in terms of social participation for people with dementia. Method: Semi-structured interviews were conducted with people with dementia who attended day services at a GCF (GCF group, n = 21, were on a waiting list (WL for day services at a GCF (WL group, n = 12, or attended day services in a regular day care facility (RDCF group, n = 17 and with their family caregivers. Results: People with dementia in the GCF and WL group were primarily males, with an average age of 71 and 76 years, respectively, who almost all had a spousal caregiver. People with dementia in the RDCF group were mostly females with an average age of 85 years, most of whom had a non-spousal caregiver. For both the GCF and RDCF groups, it was indicated that day services made people with dementia feel part of society. The most important domains of social participation addressed by RDCFs were social interactions and recreational activities. GCFs additionally addressed the domains “paid employment” and “volunteer work.” Conclusion: GCFs are valuable in terms of social participation for a particular group of people with dementia. Matching characteristics of adult day services (ADS centers to the preferences and capacities of people with dementia is of importance. Diversity in ADS centers is therefore desirable.

  18. Changing Relations between High Castes and Tamang in Melamchi Valley

    Directory of Open Access Journals (Sweden)

    Binod Pokharel

    2011-04-01

    Full Text Available This paper is about the processes of transformation of social relations between high caste groups and Tamang in Melamchi Valley for the period of 1980-2010. Development interventions made by government of Nepal and (I NGOs, a decade long undergoing Melamchi Water Supply Project and labor migration are major factors for ongoing changes in the study area. Spread of literacy classes and primary education, availability of credit institutions, introduction of modern farming, road networks, seasonal out migration from the area, etc. primarily define new relations among the groups. Borrowing and lending money were one of the basis of high caste and Tamang relation in past. The latter was regarded as borrower loan from first one. Before 1980s, money and agriculture commodities were controlled by few rich and high castes people. Cash income from various sources made enable the Tamang to stand on an equal footing with high caste people. Open political economy and liberal policy for issuing pass port in 1990s and after that encourage the people to diversify the destination of seasonal migration from India to Gulf countries and East Asia. Various processes of socio-economic and political changes led to local peoples to seek their position and identity in the changing context. Discourse of Tamang, high castes and Dalit entered into the Valley along with the development resources of (INGO and political movements of the country. This made possible to Tamang and other disadvantage groups to define and redefine their ethnic identity. Keywords: High castes; Tamang; credit facilities; subsistence farming; identity construction; money lending; wage labor DOI: 10.3126/dsaj.v4i0.4513 Dhaulagiri Journal of Sociology and Anthropology Vol.4 2010 pp.65-84

  19. Roy Fuentes: Fuentes Berry Farms

    OpenAIRE

    Rabkin, Sarah

    2010-01-01

    As president of Fuentes Berry Farms, Rogelio (Roy) Fuentes is one of many independent growers producing organic berries for Driscoll’s—a company that was initiated more than a century ago by two strawberry farmers on California’s Central Coast, and has since evolved into an international concern devoted to research, breeding, production, sales and distribution of conventionally and organically farmed strawberries, raspberries, blackberries and blueberries. Driscoll’s CEO Miles Reiter and his ...

  20. Whole Farm Management to Reduce Nutrient Losses From Dairy Farms: A Simulation Study

    NARCIS (Netherlands)

    Rotz, C.A.; Oenema, J.; Keulen, van H.

    2006-01-01

    Whole-farm simulation provides a tool for evaluating long-term impacts of nutrient conservation technologies and strategies on dairy farms. A farm simulation model was verified to predict the production and nutrient flows of the De Marke experimental dairy farm in the Netherlands. On this farm,

  1. Technical Analysis of In-Valley Drainage Management Strategies for the Western San Joaquin Valley, California

    Science.gov (United States)

    Presser, Theresa S.; Schwarzbach, Steven E.

    2008-01-01

    The western San Joaquin Valley is one of the most productive farming areas in the United States, but salt-buildup in soils and shallow groundwater aquifers threatens this area?s productivity. Elevated selenium concentrations in soils and groundwater complicate drainage management and salt disposal. In this document, we evaluate constraints on drainage management and implications of various approaches to management considered in: *the San Luis Drainage Feature Re-Evaluation (SLDFRE) Environmental Impact Statement (EIS) (about 5,000 pages of documentation, including supporting technical reports and appendices); *recent conceptual plans put forward by the San Luis Unit (SLU) contractors (i.e., the SLU Plans) (about 6 pages of documentation); *approaches recommended by the San Joaquin Valley Drainage Program (SJVDP) (1990a); and *other U.S. Geological Survey (USGS) models and analysis relevant to the western San Joaquin Valley. The alternatives developed in the SLDFRE EIS and other recently proposed drainage plans (refer to appendix A for details) differ from the strategies proposed by the San Joaquin Valley Drainage Program (1990a). The Bureau of Reclamation (USBR) in March 2007 signed a record of decision for an in-valley disposal option that would retire 194,000 acres of land, build 1,900 acres of evaporation ponds, and develop a treatment system to remove salt and selenium from drainwater. The recently proposed SLU Plans emphasize pumping drainage to the surface, storing approximately 33% in agricultural water re-use areas, treating selenium through biotechnology, enhancing the evaporation of water to concentrate salt, and identifying ultimate storage facilities for the remaining approximately 67% of waste selenium and salt. The treatment sequence of reuse, reverse osmosis, selenium bio-treatment, and enhanced solar evaporation is unprecedented and untested at the scale needed to meet plan requirements. All drainage management strategies that have been proposed

  2. Ships as future floating farm systems?

    Science.gov (United States)

    Moustafa, Khaled

    2016-09-29

    Environmental and agriculture challenges such as severe drought, desertification, sprawling cities and shrinking arable lands in large regions in the world compel us to think about alternative and sustainable farming systems. Ongoing projects to build floating cities in the sea suggest that building specific ships for farming purposes (as farming ships or farming boats) would also be attainable to introduce new farming surfaces and boost food production worldwide to cope with food insecurity issues.

  3. Data Farming in Support of NATO

    Science.gov (United States)

    2014-03-01

    Farming into Decision Support System 5-29 Figure 6-1 The Credo of a Data Farmer and the Realms of Data Farming 6-2 Figure 6-2 Data Farming is Question...Figure 6-1: The Credo of a Data Farmer and the Realms of Data Farming. All 6 realms are covered by a sub-working group of MSG-088 Data Farming. As Figure

  4. Linking Organic Matter Deposition And Iron Mineral Transformations to Groundwater Arsenic Levels in the Mekong Delta, Cambodia

    Energy Technology Data Exchange (ETDEWEB)

    Quicksall, A.N.; Bostick, B.C.; Sampson, M.L.

    2009-05-21

    Enriched As in drinking water wells in south and Southeast Asia has increased the risk of cancer for nearly 100 million people. This enrichment is generally attributed to the reductive dissolution of Fe oxides; however, the complex expression of As enrichment in these areas is not yet well understood. Here, the coupled sedimentological and geochemical factors that contribute to the extent and spatial distribution of groundwater As concentrations in the Mekong River delta, Cambodia in an avulsed scroll bar sequence are examined. X-Ray absorption spectroscopy (XAS) was used to determine Fe and As speciation in redox preserved sediment collected from drilled cores. Dissolved As, Fe and S solution concentrations in existing and newly drilled wells (cores) differed considerably depending on their source sedimentology. The rapid burial of organic matter in the scroll bar sequence facilitated the development of extensive Fe-reducing conditions, and As release into the aquifer. In older features organic C levels are high enough to sustain extensive Fe reduction and provide ample SO{sub 4} which is reduced to sulfide. This S reduction impacts As levels; As is sequestered in sulfide minerals outside of the scrollbar sequence, decreasing pore water concentrations. In contrast, As is depleted in sediments from the scroll sequence, and associated with elevated pore water aqueous concentrations. The concentration and form of organic C in the scrollbar sequence is related to depositional environment, and can facilitate Fe and S mineral transformations, distinct sedimentary environments explain a portion of the inherent heterogeneity of aquifer As concentrations.

  5. Effective management for acidic pollution in the canal network of the Mekong Delta of Vietnam: a modeling approach.

    Science.gov (United States)

    Phong, Ngo Dang; Hoanh, Chu Thai; Tuong, To Phuc; Malano, Hector

    2014-07-01

    Acidic pollution can cause severe environmental consequences annually in coastal areas overlain with acid sulfate soils (ASS). A water quality model was used as an analytical tool for exploring the effects of water management options and other interventions on acidic pollution and salinity in Bac Lieu, a coastal province of the Mekong Delta. Fifty eight percent of the provincial area is covered by ASS, and more than three-fourths (approximately 175,000 ha) are used for brackish-water shrimp culture. Simulations of acid water propagation in the canal network indicate that the combination of opening the two main sluices along the East Sea of the study area at high tide for one day every week in May and June and widening the canals that connect these sluices to the West Sea allows for adequate saline water intake and minimizes the acidic pollution in the study area. On the other hand, canal dredging in the freshwater ASS area should be done properly as it can create severe acidic pollution. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Treating the Hooking Effect in Satellite Altimetry Data: A Case Study along the Mekong River and Its Tributaries

    Directory of Open Access Journals (Sweden)

    Eva Boergens

    2016-01-01

    Full Text Available This study investigates the potential of satellite altimetry for water level time series estimation of smaller inland waters where only very few measurements above the water surface are available. A new method was developed using off-nadir measurements to estimate the parabola generated by the hooking effect. For this purpose, a new waveform retracker was used as well as an adopted version of the RANdom SAmple Consensus (RANSAC algorithm. The method is applied to compute time series of the water levels height of the Mekong River and some of its tributaries from Envisat high-frequency data. Reliable time series can be obtained from river crossings with widths of less than 500 m and without direct nadir measurements over the water. The expected annual variations are clearly depicted and the time series well agree with available in situ gauging data. The mean RMS value is 1.22 m between the resulting time series and in situ data, the best result is 0.34 m, the worst 2.26 m, and 80% of the time series have an RMS below 1.5 m.

  7. Sex pheromones of three citrus leafrollers, Archips atrolucens, Adoxophyes privatana, and Homona sp., inhabiting the Mekong Delta of Vietnam.

    Science.gov (United States)

    Van Vang, Le; Thuy, Ho Nhu; Khanh, Chau Nguyen Quoc; Son, Pham Kim; Yan, Qi; Yamamoto, Masanobu; Jinbo, Utsugi; Ando, Tetsu

    2013-06-01

    Archips atrolucens, Adoxophyes privatana, and Homona sp. are serious defoliators of citrus trees in the Mekong Delta of Vietnam. In order to establish a sustainable pest-management program for the three species, their female-produced sex pheromones were investigated by GC-EAD and GC-MS analyses, and the following multi-component pheromones were identified: (Z)-11-tetradecenyl acetate (Z11-14:OAc), (E)-11-tetradecenyl acetate (E11-14:OAc), and tetradecyl acetate (14:OAc) in a ratio of 64:32:4 for A. atrolucens; Z11-14:OAc and (Z)-9-tetradecenyl acetate (Z9-14:OAc) in a ratio of 92:8 for A. privatana; and Z11-14:OAc and (Z)-9-dodecenyl acetate (Z9-12:OAc) in a ratio of 96:4 for Homona sp. Each lure baited with synthetic components as a mimic of the natural pheromone attracted males of the target species specifically, indicating that each monounsaturated minor component plays a significant role for mating communication and reproductive isolation of the three species inhabiting the same citrus orchards. In an extract of the pheromone glands of A. atrolucens females, the content of 14:OAc was very low, but a synergistic effect was observed clearly when the saturated compound was mixed at the same level as the E11-14:OAc. The synthetic lures will provide useful tools for monitoring flights of adults of the three species.

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

    Science.gov (United States)

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

    2013-11-01

    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 (NH4, NO3, NO2, o-PO4), 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.

  9. Communication and social capital in the control of avian influenza: lessons from behaviour change experiences in the Mekong Region.

    Science.gov (United States)

    Waisbord, S R; Michaelides, T; Rasmuson, M

    2008-01-01

    International development agencies, national governments, and nongovernmental organizations are increasingly collaborating with local civil society groups in mounting behaviour change communication (BCC) interventions. Even in countries with weakened civil societies, the social capital of local organizations can be a fundamental communication resource. The experience of three programmes in the Mekong Region that used BCC to prevent and control outbreaks of avian influenza bore out this finding. These programmes worked with the Vietnam Women's Union to mobilize local women as conduits for education; worked with the Centre d'Etude et de Developpement Agricole Cambodgien (CEDAC), in Cambodia, to educate and train village health promoters and model farmers; and worked with the Lao Journalists Association to educate and build skills among print and broadcast journalists to enhance avian influenza coverage. Collaborating with civil society organizations can enhance communication reach, trust, and local ownership, but poses many challenges, particularly institutional capacity. Our experience, nevertheless, holds promise for a measured approach that views social capital as a set of communication resources at the community level that can be mobilized to promote complex behaviours, particularly in a rapidly changing outbreak situation.

  10. Impacts of agricultural land use on stream benthic macroinvertebrates in tributaries of the Mekong River, northeast Thailand

    Directory of Open Access Journals (Sweden)

    Narumon Sangpradub

    2010-11-01

    Full Text Available Ecological impacts of non-intensive agricultural activities on stream community, especially inheadwater streams adjacent to conserved areas, are poorly known in Thailand. We investigated theimpacts of non-intensive agricultural activities on stream habitat characteristics and benthicmacroinvertebrate community in the headwater streams, tributaries of the Mekong River, northeastThailand. We compared the streams running through forests in National Parks and Wildlife Sanctuariesand those through agricultural areas. Twenty kick samples of benthic macroinvertebrates werecollected using a D-frame dipnet (0.3 m wide, 450 μm mesh size from each sampling site. Sixteenphysicochemical parameters of stream characteristics were measured. The results suggested that thisdisturbance had an impact on stream habitats more than its community. Agricultural land use alteredthe streams to be wider, deeper, and more discharged with less percentage of riparian coverage andhigh water temperature. Benthic macroinvertebrate composition did not differ in both areas, butintolerant benthic fauna decreased, while tolerant taxa were predominant and more abundant in theagricultural areas. In this study, water velocity and water temperature are the major importantvariables related to the distribution of benthic macroinvertebrates.

  11. 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.

  12. Chemical weathering and long-term CO2 consumption in the Ayeyarwady and Mekong river basins in the Himalayas

    Science.gov (United States)

    Manaka, Takuya; Otani, Souya; Inamura, Akihiko; Suzuki, Atsushi; Aung, Thura; Roachanakanan, Raywadee; Ishiwa, Takeshige; Kawahata, Hodaka

    2015-06-01

    The role of terrestrial river systems in the global carbon cycle on a long timescale has been a subject of interest, especially in the context of past climate changes such as the global cooling in the Cenozoic. The discharges of water and carbon into the ocean from the Himalayan watersheds are among the highest in the world. However, there are few reliable geochemical data from the Ayeyarwady River. This study focused on reevaluating chemical weathering in the Himalayan watersheds based on samples taken from the Ayeyarwady, Mekong, and Chao Phraya Rivers and on chemical analysis of the composition of dissolved substances in these rivers. Comparisons of water quality showed that, unlike in previous studies, the total alkalinity budgets of the Ayeyarwady are dominated by carbonate rather than silicate weathering. Long-term CO2 consumption by silicate weathering in the Ayeyarwady is estimated to be only 63-145 × 109 mol yr-1, which is only 10% of the previous estimate. Our results also suggest that the total Himalayan watersheds account for only about 10% of the total global CO2 consumption by silicate weathering. Although we need further studies, chemical weathering and associated CO2 uptake in the Himalayas likely played a lesser role in long-term global cooling in the past than previously appreciated.

  13. Spatiotemporal analysis of temperature-variation patterns under climate change in the upper reach of Mekong River basin.

    Science.gov (United States)

    Wu, Feifei; Wang, Xuan; Cai, Yanpeng; Yang, Zhifeng; Li, Chunhui

    2012-06-15

    Occurrence of temperature anomaly has greatly affected natural cycles of water resources in Lancang River basin in China, which is the upper reach of Mekong River. An integrated spatiotemporal decomposition and analysis method was proposed for the identification of temperature-variation patterns under changing climatic conditions in the basin. This method was based on the combination of S-mode empirical orthogonal function analysis, IDW interpolation, liner regression, weighted moving average and Mann Kendall methods. Results indicated that the first two modes extracted nearly 80% of spatiotemporal variations in temperature. Temperature in the whole basin followed the same variation trend through the first mode analysis. Sensitive areas were mainly located in the southwest of the basin, which occupied nearly half of the basin. The associated time series presented that the basin appeared transition from cold periods to warm periods. Temperature increased significantly over the period of 1960 to 2009 at annual and seasonal scales, particularly over 1990s. At the same time, the most significant rising occurred in winter and the least in summer. In the second mode, a west-east inverse phase pattern of temperature variations was a distinct feature in most of the basin. Temporal trend indicated that the increasing trend in the west region was slightly stronger than that in the east. This was particularly the case of edge areas almost vertical juncture with monsoons. This research is not only helpful in improving understanding of temperature response to global warming in the basin but also provides a basis for basin management.

  14. Mid-Holocene mangrove succession and its response to sea-level change in the upper Mekong River delta, Cambodia

    Science.gov (United States)

    Li, Zhen; Saito, Yoshiki; Mao, Limi; Tamura, Toru; Li, Zhen; Song, Bing; Zhang, Yulan; Lu, Anqing; Sieng, Sotham; Li, Jie

    2012-09-01

    Middle Holocene vegetation and mangrove successions are clearly evident in the palynological records of two cores from the upper Mekong River delta in Cambodia. Spanning from ~ 9.4 to 6.3 cal ka BP, the cores mainly record a transgressive sequence from floodplain freshwater marsh to tidal flat, which was overlain by mangrove. Corresponding to the decelerated sea-level rise at ~ 8.3 cal ka BP, pioneer mangrove species Sonneratia alba and Sonneratia caseolaris appeared in the sediments, and then was replaced by regressive mangrove succession containing upward-increasing abundances of Rhizophora apiculata and Bruguiera spp. High salinity- and flooding-tolerant community S. alba was developed at the western core site PSG at ~ 8.2 cal ka BP, and the eastern core site PK at ~ 7.5 cal ka BP. The time difference of S. alba appearance between the two sites might be resulted from the complexity of sedimentary environment, where a higher sediment supply was provided to the western floodplain than to the eastern floodplain. After 7.5 cal ka BP, aggradational stacking of intertidal sediments, of which the thickness is larger than the present maximum tidal range, may have resulted from continuous sea-level rise during 7.5-7.0 cal ka BP.

  15. The challenge of artemisinin resistance can only be met by eliminating Plasmodium falciparum malaria across the Greater Mekong subregion.

    Science.gov (United States)

    Smith Gueye, Cara; Newby, Gretchen; Hwang, Jimee; Phillips, Allison A; Whittaker, Maxine; MacArthur, John R; Gosling, Roly D; Feachem, Richard G A

    2014-01-01

    Artemisinin-based combinations are currently the most effective anti-malarials and, in addition to vector control, have led to significant declines in malaria morbidity and mortality. However, foci of artemisinin drug resistance have been identified in the Greater Mekong subregion (GMS) of the Asia Pacific, threatening the major gains made in malaria control and potentially creating a parasite pool that is more difficult to treat and eliminate. Efforts are underway to halt the spread of artemisinin resistance, including coordination of activities and funding, and identification of areas of suspected artemisinin resistance, now using a newly identified molecular marker. However, targeting resources to the containment of resistant parasites is likely inefficient and monitoring impact is challenging. A more sustainable solution is the rapid elimination of all Plasmodium falciparum parasites from the GMS. This strategy is more efficient for several reasons. First, a subregional strategy is in line with current commitment to elimination and will build upon the existing national political support for elimination as well as enhancing collaboration among countries. Second, the challenge of human mobility in the GMS is subregional in scope and requires a harmonized elimination strategy. Third, countries will need to improve and intensify malaria operations to reach elimination, and this will be a singular goal across the subregion. Rallying around the goal of P. falciparum elimination will not only utilize existing regional bodies to catalyze political and funding support, but will also leverage the funding already in place to achieve this subregional goal.

  16. Got Milk? Got Water? Innovative Approach to Evaluating Groundwater Nitrate Nonpoint Source Pollution from Animal Farming

    Science.gov (United States)

    Harter, T.; Vanderschans, M.; Leijnse, A.; Meyer, R. D.; Mathews, M. C.

    2002-12-01

    The California dairy industry produces 20% of US milk and is the largest animal industry in the state. Many of the dairy facilities are located in low-relief valleys and basins with vulnerable groundwater resources. The continued influx of dairies into California's Central Valley has raised critical questions regarding their environmental performance, in particular with respect to groundwater quality impacts. While animal farming systems are considered among the leading sources of groundwater nitrate,little is known about the actual impact of dairy farming practices on groundwater quality in the extensive alluvial aquifers underlying the Central Valley. With our work we attempt to characterize and assess shallow groundwater underneath dairies in a relatively vulnerable hydrogeologic region and to discern the impact from various individual sources and management practices within dairies. An extensive shallow groundwater monitoring network was installed on five representative dairy operations in the northeastern San Joaquin Valley, California. The monitoring network spans all dairy management units: manure water lagoons, corrals, storage areas, and manure treated forage fields under various management practices. We recently also surveyed production well water quality. Water quality is found to be highly variable, both in time and space. We propose that a meaningful interpretation of these (nonpoint source pollution) data is only possible by explicitly considering the various scales affiliated with groundwater measurement, pollution source management, regulatory control, and beneficial use. Using statistical analysis and innovative modeling tools, we provide an interpretation of the observed data that is meaningful at the field scale (the scale unit of management decisions), the farm scale (considered to be a regulatory and planning unit), and the regional scale (considered to be a planning unit).

  17. Farm Biogas Handbook; Gaardsbiogashandbok

    Energy Technology Data Exchange (ETDEWEB)

    Christensson, Kjell; Bjoernsson, Lovisa; Dahlgren, Stefan; Eriksson, Peter; Lantz, Mikael; Lindstroem, Johanna; Mickelaaker, Maria

    2009-04-15

    A very large share of the total raw material potential for biogas production will be found within the agriculture. The raw material potential of manure in Sweden amounts to 4 - 6 TWh. Within the agriculture there is moreover a big potential in the form of residues from plant cultivation and non-food crops (approximately 7 TWh) that can to be used for biogas production. The potential for biogas production from only residues and manure is around 8-10 TWh. An increased biogas production within the agriculture would give significant environmental effects. Among other things manure, that today is leaking methane gas to the atmosphere, can be fermented, and trough this process the methane losses will be reduced. When the produced biogas replaces fossil fuel, an overall environmental effect will be reached, that is highly significant. This manual deals with biogas plants for agriculture and such plants that do not have extensive transports of different raw materials, as manure, wastes etc. One of the starting points for this manual's set-up is a course plan that Biogas Syd made for the courses they give to farmers, advisors and others. The manual illustrates important aspects in planning and construction of biogas plants, from raw material and technology to dimensioning of plant, use of biogas and planning of local gas grids. We also think it is important to illustrate the legislation that encompasses construction work and operation of a biogas plant. Investment costs are also illustrated, but the book does not give any extensive economic calculations, since we believe that such calculations need their own manual in the form of calculation examples, based on various conditions. The final section is called 'Biogas on farm - from idea to reality' where the entire process from analysis and pre-planning to monitoring and control of plant during operation is briefly described

  18. Mechanically and optically controlled graphene valley filter

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Fenghua; Jin, Guojun, E-mail: gjin@nju.edu.cn [National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093 (China)

    2014-05-07

    We theoretically investigate the valley-dependent electronic transport through a graphene monolayer modulated simultaneously by a uniform uniaxial strain and linearly polarized light. Within the Floquet formalism, we calculate the transmission probabilities and conductances of the two valleys. It is found that valley polarization can appear only if the two modulations coexist. Under a proper stretching of the sample, the ratio of the light intensity and the light frequency squared is important. If this quantity is small, the electron transport is mainly contributed by the valley-symmetric central band and the conductance is valley unpolarized; but when this quantity is large, the valley-asymmetric sidebands also take part in the transport and the valley polarization of the conductance appears. Furthermore, the degree of the polarization can be tuned by the strain strength, light intensity, and light frequency. It is proposed that the detection of the valley polarization can be realized utilizing the valley beam splitting. Thus, a graphene monolayer can be used as a mechanically and optically controlled valley filter.

  19. Zhongguan Village, China's Silicon Valley

    Institute of Scientific and Technical Information of China (English)

    Liu Xinwen

    2008-01-01

    @@ In 1999,driven by the dream of using technology to change people's lives,Li Yanhong,returned to Zhongguancun(Zhongguan Village in Chinese),Beijing from Silicon Valley in the U.S.to create Baidu.com.Over the years,Baidu has become the most frequently hitted website in China as well as the largest Chinesc search engine and Chinese language website in the world.

  20. Effect of farming practices and farm history on incidence of coconut ...

    African Journals Online (AJOL)

    Effect of farming practices and farm history on incidence of coconut lethal yellowing in Mozambique. ... African Crop Science Journal ... to investigate the impact of farming practices and related history, on the CLYD incidence in Mozambique.

  1. CleverFarm final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-09-15

    Wind turbine technology has ventured in recent years from prototypes and first deployments towards large power plant scale projects. With this, also the ownership structure of wind farms changed: from single farmers to cooperatives, and to large multi-national developers specialised in building and running wind power projects. At the same time, the best sites for wind energy were already taken, leading to more remote sites and offshore sites being developed. Both these developments lead to an increased wish for remote monitoring of turbines. Ideally, the turbine would know on its own accord when it would need maintenance, and call the maintenance crew autonomously. The crew then would have all the information they need to have before they go out to the turbine and do the necessary tasks. Having knowledge of the type of fault that has happened would help the maintenance crew to deal with it efficiently. This also could mean to wait until the next scheduled maintenance is due. The potential savings for this alone are considerable, if you think of the plans for offshore wind farms tens of kilometres from the coast, where access would probably be by helicopter. The idea behind this project was to take the existing techniques developed for optimising and enhancing the performance of wind farms, integrate them into one system and implement the system at a number of wind farms. The techniques include remote measuring of the status and production of the wind farm, short-term prediction of the expected wind speeds at and power output from the wind farm, models for wake calculations, remote control of wind farm production and so on. (au)

  2. CleverFarm final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-09-15

    Wind turbine technology has ventured in recent years from prototypes and first deployments towards large power plant scale projects. With this, also the ownership structure of wind farms changed: from single farmers to cooperatives, and to large multi-national developers specialised in building and running wind power projects. At the same time, the best sites for wind energy were already taken, leading to more remote sites and offshore sites being developed. Both these developments lead to an increased wish for remote monitoring of turbines. Ideally, the turbine would know on its own accord when it would need maintenance, and call the maintenance crew autonomously. The crew then would have all the information they need to have before they go out to the turbine and do the necessary tasks. Having knowledge of the type of fault that has happened would help the maintenance crew to deal with it efficiently. This also could mean to wait until the next scheduled maintenance is due. The potential savings for this alone are considerable, if you think of the plans for offshore wind farms tens of kilometres from the coast, where access would probably be by helicopter. The idea behind this project was to take the existing techniques developed for optimising and enhancing the performance of wind farms, integrate them into one system and implement the system at a number of wind farms. The techniques include remote measuring of the status and production of the wind farm, short-term prediction of the expected wind speeds at and power output from the wind farm, models for wake calculations, remote control of wind farm production and so on. (au)

  3. Early Performance of Duong Mandarin (Citrus reticulata Blanco on Three Rootstock under Acid Sulfate Soil Fields at Mekong Delta of Vietnam

    Directory of Open Access Journals (Sweden)

    Khoe Thi Le

    2016-01-01

    Full Text Available Abstract About 1.6 billion hectare area of acid sulfate soils is at Mekong Delta of Vietnam, and Duong mandarin fruits are valued for the fresh market due to the easy peeling, attractive flavor, and health and nutritional properties; thereby, the investigation on early performance of Duong mandarin on three rootstock under acid sulfate soil fields (pH below 4 at Mekong Delta of Vietnam was undertaken from 2009 to 2012 for determination of the most promising scion stock combination of Duong mandarin, which introduced to growers for expanding citrus production to increase in income of farmers, and helping to use the sustainable and efficient land resource at acid sulfate soil region of Mekong Delta. Primary results showed that Duong mandarin grafted on Mat orange, Tau lemon and Carrizo citrange were significant differenence in vegetative parameters, fruit yield and quality. It proved that Duong mandarin trees grafted on Tau lemon were better growth and development on acid sulfate soil fields with below 4 pH in soil and water suspension of 1:2.5 ratio as compared to those grafted on Mat orange and Carrizo citrange rootstocks; whereby, that induced trees with 171.48 cm height, 6.65 m3 canopy volume and 51.84 mm trunk diameter, 1.08 scion/ stock ratio in third year after growing. Moreover, Duong mandarin trees grafted on Tau lemon were with spreading growth performance. In regarding to fruit yield and quality, Duong mandarin trees grafted on Tau lemon produced highest fruit yield of 9.21 kg per tree per year in third year after planting, and fruit with 115.30g weight, 8.85 brix juice, thinner and somewhat easy peel rind. 

  4. Energy sector integration for low carbon development in Greater Mekong sub-region: Towards a model of South-South cooperation

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Yongping

    2010-09-15

    The Greater Mekong Sub-region (GMS) in Southeast Asia has embarked on a roadmap of power interconnection and expanded energy sector cooperation. An Asian development bank committed study using Model of Energy Supply Systems Alternatives and their General Environmental Impacts (MESSAGE) assessed the impacts of various scenarios, the results indicate that GMS integration will help these countries to achieve low carbon and sustainable development. The article suggests that the experience of GMS cooperation be made a model for South-South cooperation in the global effort to fight climate change.

  5. 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

  6. Water turbidity monitoring from Landsat data before and after the 2016 El Niño in the Mekong and Bassac Rivers, Vietnam

    Science.gov (United States)

    Lau, K. V.; Chen, C. F.; Nguyen, S. T.; Lam, N. D.; Chen, C. R.

    2016-12-01

    The water turbidity is not only used as an indicator of water quality but also known as the carrying of sediment from upstream to downstream. It is a very important factor for agriculture acting as natural fertilizers for crop production. Traditional studies of water turbidity are often applied to a small region, implemented through costly and time-consuming field surveys. Remote sensing technologies such as aerial photography and satellites have been an indispensable tool for water turbidity monitoring, due to their ability to acquire data over large regions. Besides a series of hydropower dams constructed in the upper stream along the Mekong River that interrupt water discharge, the occurrence of El Niño in 2015-2016 caused severe droughts in the downstream of Vietnamese Mekong Delta. The main object of this study is to investigate the applicability of Landsat data for water turbidity monitoring in Mekong and Bassac Rivers, Vietnam before and after the El Niño. The Landsat-8 satellite launched in 2013 provides the multispectral bands and 30 m resolution, which are deemed suitable for turbidity monitoring were used in this study. The data were processed through three main steps. The first step was to establish a turbidity model using field survey data. The second step was to apply the turbidity model to the entire study region from May 2013 to June 2016. Eventually, the analysis of water turbidity variation was performed to investigate its spatiotemporal changes. The turbidity model results given a good correlation between Landsat bands and water turbidity with R2 of 0.86. The validation results also yielded a close agreement with R2 of 0.79. The turbidity variation results showed that the turbidity in the upstream is lower than in the downstream. Before the occurrence of El Niño in Jan 2015, the water turbidity concentration was relatively high in the rainy season and low during the dry season. However, when this phenomenon occurred, the lower water turbidity

  7. TOPFARM wind farm optimization tool

    Energy Technology Data Exchange (ETDEWEB)

    Rethore, P.-E.; Fuglsang, P.; Larsen, Torben J.; Buhl, T.; Larsen, Gunner C.

    2011-02-15

    A wind farm optimization framework is presented in detail and demonstrated on two test cases: 1) Middelgrunden and 2) Stags Holt/Coldham. A detailed flow model describing the instationary flow within a wind farm is used together with an aeroelastic model to determine production and fatigue loading of wind farm wind turbines. Based on generic load cases, the wind farm production and fatigue evaluations are subsequently condensed in a large pre-calculated database for rapid calculation of lifetime equivalent loads and energy production in the optimization loop. The objective function defining the optimization problem includes elements as energy production, turbine degradation, operation and maintenance costs, electrical grid costs and foundation costs. The objective function is optimized using a dedicated multi fidelity approach with the locations of individual turbines in the wind farm spanning the design space. The results are over all satisfying and are giving some interesting insights on the pros and cons of the design choices. They show in particular that the inclusion of the fatigue loads costs give rise to some additional details in comparison with pure power based optimization. The Middelgrunden test case resulted in an improvement of the financial balance of 2.1 M Euro originating from a very large increase in the energy production value of 9.3 M Euro mainly counterbalanced by increased electrical grid costs. The Stags Holt/Coldham test case resulted in an improvement of the financial balance of 3.1 M Euro. (Author)

  8. Spin-Valley Beam Splitter in Graphene

    CERN Document Server

    Song, Yu; Shi, Zhi-Gui; Li, Shun; Zhang, Jian

    2016-01-01

    The fourfold spin-valley degenerate degrees of freedom in bulk graphene can support rich physics and novel applications associated with multicomponent quantum Hall effects and linear conductance filtering. In this work, we study how to break the spin-valley degeneracy of electron beams spatially. We propose a spin-valley beam splitter in a gated ferromagnetic/pristine/strained graphene structure. We demonstrate that, in a full resonant tunneling regime for all spin-valley beam components, the formation of quasi-standing waves can lead four giant lateral Goos-H\\"{a}nchen shifts as large as the transverse beam width, while the interplay of the two modulated regions can lead difference of resonant angles or energies for the four spin-valley flavors, manifesting an effective spin-valley beam splitting effect. The beam splitting effect is found to be controllable by the gating and strain.

  9. California's restless giant: the Long Valley Caldera

    Science.gov (United States)

    Hill, David P.; Bailey, Roy A.; Hendley, James W.; Stauffer, Peter H.; Marcaida, Mae

    2014-01-01

    Scientists have monitored geologic unrest in the Long Valley, California, area since 1980. In that year, following a swarm of strong earthquakes, they discovered that the central part of the Long Valley Caldera had begun actively rising. Unrest in the area persists today. The U.S. Geological Survey (USGS) continues to provide the public and civil authorities with current information on the volcanic hazard at Long Valley and is prepared to give timely warnings of any impending eruption.

  10. Farm animal proteomics - A review

    DEFF Research Database (Denmark)

    Bendixen, Emøke; Danielsen, Marianne; Hollung, Kristin

    2011-01-01

    in large-scale operations, with the aim to obtain animal products for human consumption. Hence, understanding the biological traits that impact yield and quality of these products is the specific aim of much biological experimentation. However, most of the data gathered from experiments on e.g. swine......In agricultural sciences as in all other areas of life science, the implementation of proteomics and other post-genomic tools is an important step towards more detailed understanding of the complex biological systems that control physiology and pathology of living beings. Farm animals are raised...... and cattle are relevant not only for farm animal sciences, but also for adding to our understanding of complex biological mechanisms of health and disease in humans. The aim of this review is to present an overview of the specific topics of interest within farm animal proteomics, and to highlight some...

  11. Analysis of the Solar Resource Information Datasets for Thermal and/or electric Generation Using a Geographical Information System. Cases of Application: Central Cafeteria - University of the Valley, Cali Municipality and Farm {sup P}ozo Verde{sup ,} Jamundi Municipality , Cauca Valley, Colombia; Analisis de las Fuentes de Informacion sobre Recurso Solar para Generacion Termica y/o Electrica Empleando un Sistema de Informacion Geografica. Casos de Aplicacion: Cafeteria Central - Universidad del Valle, Municipio de Cali y Granja {sup P}ozo Verde{sup ,} Municipio de Jamundi, Valle del Cauca, Colombia

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, J.; Manrique, P. A.; Pinedo, I.

    2009-10-12

    In this report, two examples of renewable energy assessments based on Geographical Information Systems are presented. Several case studies have been carried out in the Valley of Cauca (Colombia), and one on them has been used to size a hybrid system. The results of this particular case study are presented in a second report. The aim of this document is analysing the different sources of data that could be used in the characterization of solar energy for electricity and electricity-heat use. With this purpose, data of two areas in Valley of Cauca obtained from the Atlas of Solar Radiation of Colombia, SWERA project and SSE-NASA have been compared. The data coming from these sources has been analysed using a Geographical Information System, and the conclusions are described along with cartographic and numeric products. These reports are the result of a collaboration established between Universidad del Valle (Colombia) and CIEMAT (Spain), and have been done by the author while his staying at our center included on his PhD program.

  12. Intrinsic valley Hall effect in graphene

    Science.gov (United States)

    Yang, Mou; Zhang, Wen-Lian; Liu, Hai; Bai, Yan-Kui

    2017-04-01

    If electrons are incident from an armchair graphene ribbon into the bulk graphene region, the electronic diffraction occurs. Because of the different triangular wrapping of the energy dispersion between valleys K and K ‧ , the electrons of valley K tend to be diffracted to one side and those of valley K ‧ to the other side. When the current is injected from the armchair ribbon of a four-terminal graphene device, the major portion of the incident current of valley K flows through one side arm and the minor portion through the other side arm. The ratio between them is derived to be 1 + 4 E / 3 in the low energy limit, where E is the energy in units of hopping parameter. The major arm for valley K is the minor arm for valley K ‧ . This results in the rise of the valley Hall effect, which is an intrinsic property of graphene stemming from the different electronic structure of the two valleys. The valley Hall conductance is calculated to be (2 E / 3)G0 with G0 being the conductance supported by the injection ribbon.

  13. Trion valley coherence in monolayer semiconductors

    Science.gov (United States)

    Hao, Kai; Xu, Lixiang; Wu, Fengcheng; Nagler, Philipp; Tran, Kha; Ma, Xin; Schüller, Christian; Korn, Tobias; MacDonald, Allan H.; Moody, Galan; Li, Xiaoqin

    2017-06-01

    The emerging field of valleytronics aims to exploit the valley pseudospin of electrons residing near Bloch band extrema as an information carrier. Recent experiments demonstrating optical generation and manipulation of exciton valley coherence (the superposition of electron-hole pairs at opposite valleys) in monolayer transition metal dichalcogenides (TMDs) provide a critical step towards control of this quantum degree of freedom. The charged exciton (trion) in TMDs is an intriguing alternative to the neutral exciton for control of valley pseudospin because of its long spontaneous recombination lifetime, its robust valley polarization, and its coupling to residual electronic spin. Trion valley coherence has however been unexplored due to experimental challenges in accessing it spectroscopically. In this work, we employ ultrafast 2D coherent spectroscopy to resonantly generate and detect trion valley coherence in monolayer MoSe2 demonstrating that it persists for a few-hundred femtoseconds. We conclude that the underlying mechanisms limiting trion valley coherence are fundamentally different from those applicable to exciton valley coherence.

  14. Challenges in wind farm optimization

    DEFF Research Database (Denmark)

    Larsen, Gunner Chr.

    for the wind turbine modeling, where aeroelastic models are required, and for the wind farm flow field description, where in-stationary flow field modeling is needed to capture the complicated mixture of atmospheric boundary layer (ABL) flows and upstream emitted meandering wind turbine wakes, which together...... dictates the fatigue loading of the individual wind turbines. Within an optimization context, the basic challenge in describing the in-stationary wind farm flow field is computational speed. The Dynamic Wake Meandering (DWM) model includes the basic features of a CFD Large Eddy Simulation approach...

  15. Social-insect fungus farming

    DEFF Research Database (Denmark)

    Aanen, Duur Kornelis; Boomsma, Jacobus Jan

    2006-01-01

    Which social insects rear their own food? Growing fungi for food has evolved twice in social insects: once in new-world ants about 50 million years ago; and once in old-world termites between 24 and 34 million years ago [1] and [2] . The termites domesticated a single fungal lineage - the extant...... the farming insects with most of their food ( Figure 1 ). No secondary reversals to the ancestral life style are known in either group, which suggests that the transitions to farming were as drastically innovative and irreversible as when humans made this step about 10,000 years ago....

  16. Succession Planning in Australian Farming

    Directory of Open Access Journals (Sweden)

    John Hicks

    2012-11-01

    Full Text Available The theme of this paper is that succession planning in Australian farming is under-developed.It may be linked to economic and social change which suggests that farmers need to adapt togenerational change but this is being resisted or ignored. The implications of this are the slowdecline of family farming, a poor transfer of skills and knowledge to subsequent generationsof farmers in some parts of the agricultural sector and the potential for an extension of thefinancial services industry to develop a more effective raft of succession planning measuresto mitigate the effects of a traditional approach to succession in agriculture.

  17. To what extent does organic farming rely on nutrient inflows from conventional farming?

    Science.gov (United States)

    Nowak, Benjamin; Nesme, Thomas; David, Christophe; Pellerin, Sylvain

    2013-12-01

    Organic farming is increasingly recognized as a prototype for sustainable agriculture. Its guidelines ban the use of artificial fertilizers. However, organic farms may import nutrients from conventional farming through material exchanges. In this study, we aimed at estimating the magnitude of these flows through the quantification of nitrogen, phosphorus and potassium inflows from conventional farming to organic farming. Material inflows and outflows were collected for two cropping years on 63 farms. The farms were located in three French agricultural districts distributed over a gradient of farming activity defined by both the stocking rate and the ratio of the farm area under arable crops. Our results showed that on average, inflows from conventional farming were 23%, 73% and 53% for nitrogen, phosphorus and potassium, respectively. These inflows were strongly determined by the farm production systems. However, for farms similar in terms of production systems, the inflows also depended on the local context, such as the proximity of organic livestock farms: the reliance of organic farming on conventional farming was lower in mixed than in specialized districts. These results highlight the necessity to quantify the contribution of nutrient inflows from conventional farming when assessing organic farming and development scenarios.

  18. 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

  19. Assessing farm animal welfare without visiting the farm

    DEFF Research Database (Denmark)

    Sørensen, Jan Tind; Houe, Hans; Sandøe, Peter;

    Animal welfare is typically assessed on farms by external observers making systematic observations of animals and/or the environment. External observers are costly, and efforts to minimize the time spent by external observers are giving rise to a delicate discussion of priorities of costs, validi...

  20. Etruscan pottery from the Albegna Valley/Ager Cosanus survey

    Directory of Open Access Journals (Sweden)

    Phil Perkins

    1998-07-01

    Full Text Available This study presents some of the results of 18 years of research in the Albegna Valley/Ager Cosanus area, Tuscany, Italy. Thousands of artefacts have been collected and hundreds of sites recorded during this period by systematic field survey. The Albegna Valley/Ager Cosanus Survey was directed by Professor Andrea Carandini, now of the University of Rome, La Sapienza, and Professor Elisabeth Fentress, now of the American Academy at Rome. The project is a collaboration between scholars of many institutions in Italy, France and Britain and the first volume of the final report detailing and interpreting the sites located is now in press (Cambi et al, forthcoming. This study concentrates upon a part of the finds made during field walking: the ceramics dating to the Etruscan period (8th-3rd century BC. The collection largely consists of finewares, coarsewares and amphorae. Together with the study of the ceramics from the Etruscan city at Doganella (Perkins and Walker 1990, and the excavated Etruscan farm at Podere Tartuchino (Attolini and Perkins 1992, both also in the Albegna Valley, the present study forms the most extensive detailed study of Etruscan ceramics from settlements identified by systematic survey that has been made to date. Collections from individual sites have been published in the past but the Albegna Valley/Ager Cosanus is the first part of Etruria, investigated at a regional scale, where the Etruscan ceramics have been fully studied and published. The first part of the study is an account of the fieldwork and the sampling strategy which was used during the collection of the ceramics presented here. This is followed by a summary of the assemblage. The detailed catalogue of the survey finds follows and is extended by a catalogue of an out-of-context tomb group recovered during the survey. All the illustrations of the ceramics are interactive, forming a graphical interface to the data set. The full database of the ceramics is published