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Observation of organic matters concentrations in agricultural runoff in the Red River Delta (Vietnam)Le, Nhu Da, Le, Thi Phuong Quynh, Duong, Thi Thuy 13 May 2020 (has links)
Due to utilization increase of chemical fertilizers and manures and of a large water volume for irrigation, agricultural runoff has significantly accelerated water pollution. The Red River locates in Vietnam where agriculture plays an important role in the country’s economy. This paper presented the observation results of organic matters concentrations in agricultural runoff from different plant fields (vegetable, flower and rice) in the Red River Delta in 2013 -2014. The results showed that DOC concentrations varied in a high range from 1.0 mg.L-1 to 37.1 mg.L-1, averaging 10.2 ± 6.2 mg.L-1 whereas POC concentrations varied from 0.5 to 4.5 mg.L-1, averaging 1.7 ± 0.7 mg.L-1 for a total 104 samples observed. TOC concentrations in water from the vegetable and flower fields (11.7 ± 7.3 mg.L-1 and 12.6 ± 6.0 mg.L-1 respectively) were higher than the one from the rice field (8.5 ± 6.6 mg.L-1). Lower organic matters concentrations were found in the rainy season than in the dry season due to dilution process. The results suggest the needs for regularly monitoring and efforts to control organic matter pollution from agricultural runoff in the Red River basin or other river basins in developing countries. / Do sử dụng phân bón và thể tích nước tưới lớn, canh tác nông nghiệp đã và đang góp phần đáng kể gây ô nhiễm nguồn nước. Sông Hồng nằm ở Việt Nam, nơi ngành nông nghiệp đóng vai trò quan trọng trong nền kinh tế. Bài báo trình bày kết quả quan trắc hàm lượng cacbon hữu cơ (TOC) bao gồm dạng hòa tan (DOC) và không tan (POC), trong nước chảy tràn từ đất canh tác (rau, hoa, lúa) ở đồng bằng sông Hồng năm 2013 -2014. Kết quả cho thấy DOC thay đổi rất rộng từ 1,0 mg.L-1 đến 37,1 mg.L-1, trung bình đạt 10,2 ± 6,2 mg.L-1 trong khi POC thay đổi từ 0,5 mg. L-1 đến 4,5 mg.L-1, trung bình đạt 1,7 ± 0,7 mg.L-1 đối với 104 mẫu nước. TOC từ trồng rau và hoa (11,7 ± 7,3 mg. L-1 và 12,6 ± 6,0 mg.L-1) cao hơn so với trồng lúa (8,5 ± 6,6 mg. L-1). TOC trong mùa mưa thấp hơn so với mùa khô. Cần thường xuyên giám sát và nỗ lực kiểm soát ô nhiễm chất hữu cơ do nước chảy tràn từ đất canh tác ở lưu vực sông Hồng.
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Spatial and Temporal Influences of Water Quality on Zooplankton in Lake TexomaFranks, Jessica L. 05 1900 (has links)
Seventy-one aquatic species including the copepodids and nauplii were identified from Lake Texoma from August 1996 to September 1997. Zooplankton community structure, abundance and spatial and temporal distributions were compared among five lake zones delineated a priori based on chloride concentration. The zones, in order of decreasing chloride concentration, are the Red River zone (RRZ), Red river Transition zone (RRTZ), Main Lake zone (MLZ), Washita River Transition zone (WRTZ) and Washita River zone (WRZ). Bray Curtis Similarity Index showed community structure was most similar in the two Red River arm zones, the two Washita River arm zones and the MLZ. Zooplankton abundance was greatest in the Red River arm (312 org/L), intermediate in the Washita River arm (217 org/L) and least in the Main Lake body (103 org/L). A significant increase in the abundance of a deformed rotifer, Keratella cochlearis, was observed mainly in the Red River arm during a second study from March 1999 to June 1999. Seasonal dynamics, rather than spatial dynamics, were more important in structuring the zooplankton community, especially in the two river arms. Spatial variance was solely attributed to station and zone effects independent of time for a few crustacean species and many of the water quality parameters supporting the presence of longitudinal gradients of differing water quality. Three independent models (Red River arm, Washita River arm, Main Lake body) rather than a single model for the entire reservoir, best describe patterns in the zooplankton community and its relationship to seasonal, physical and chemical factors. Statistical power, sample size and taxonomic resolution were examined. When monitoring seasonal and annuals trends in abundance, the greatest statistical power was achieved by analyzing count data at taxonomic levels above genus. Taxonomic sufficiency was assessed to determine if costs could be reduced for zooplankton identifications. For water quality monitoring purposes only, it is recommended that genus identifications are sufficient if supplemented with quarterly species identifications.
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Specialty Rice Adoption, Collective Action and Marketing Channel Choice: Insights from VietnamPham, Thai Thuy 01 February 2017 (has links)
No description available.
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Review of arsenic contamination and human exposure through water and food in rural areas in VietnamHahn, Celia 21 April 2016 (has links) (PDF)
The Red River Delta in Vietnam is one of the regions whose quaternary aquifers are polluted by arsenic. Chronic toxification by arsenic can cause severe illnesses such as cancer, skin lesions, developmental defects, cardiovascular and neurological diseas-es, and diabetes. In this study, a food processing craft village in the Red River Delta was investigated regarding the potential risk faced by the population due to arsenic. The potential sources of arsenic are the groundwater, the crops grown in the sur-roundings, and animal products from local husbandry. However, the occurrence of arsenic in nature is variable, and its bioavailability and toxicity depend very much on its specification: trivalent compounds are more toxic and often more mobile than pen-tavalent compounds, while inorganic species are generally more toxic than organic ones. Local conditions, such as the redox potential, strongly influence its specification and thus potential bioavailability.
The introduction to this work elucidates the key factors which potentially cause human exposure to arsenic: the geological setting of the study area, land and water use pat-terns, and the current state of research regarding the mobilization, bioavailability and plant uptake of arsenic.
Although the study area is located in a region where the groundwater is known to be moderately contaminated by arsenic, the level of arsenic in the groundwater in the village had not previously been determined. In this study, water use in the village was examined by a survey among the farmers and by water analyses, which are present-ed in the following chapters. Four main water sources (rain, river, tube well and a pub-lic municipal waterworks) are used for the different daily activities; the highest risk to human health was found to be the bore well water, which is pumped from the shallow Holocene aquifer. The water from the bore wells is commonly used for cleaning and washing as well as to feed the animals and for food processing. Products like noodles and rice wine were examined as well as local pork and poultry. Vegetables from the gardens and rice plants from the surrounding paddy fields were sampled and ana-lyzed. All plants were found to have accumulated arsenic, leafy vegetables showing the highest arsenic concentrations.
The results are discussed and compared, and conclusions are drawn in the last part. The reducing conditions in the paddy fields are likely to have a strong influence on arsenic uptake in rice plants and on transport to the aquifer. The installation of a wastewater treatment plant under the research project INHAND, which was funded by the BMBF German Ministry of Education and Research, led to lower arsenic concen-trations in the groundwater.
Soaring industrialization, the growing population, and the consumers’ changing behav-ior will widely affect land and water use and hence the potential mobilization of arse-nic. In order to mitigate further human exposure to arsenic, wastewater needs to be treated and the reducing conditions in the rice fields need to be decreased by means of enhanced cultivation methods.
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Review of arsenic contamination and human exposure through water and food in rural areas in VietnamHahn, Celia 21 April 2016 (has links)
The Red River Delta in Vietnam is one of the regions whose quaternary aquifers are polluted by arsenic. Chronic toxification by arsenic can cause severe illnesses such as cancer, skin lesions, developmental defects, cardiovascular and neurological diseas-es, and diabetes. In this study, a food processing craft village in the Red River Delta was investigated regarding the potential risk faced by the population due to arsenic. The potential sources of arsenic are the groundwater, the crops grown in the sur-roundings, and animal products from local husbandry. However, the occurrence of arsenic in nature is variable, and its bioavailability and toxicity depend very much on its specification: trivalent compounds are more toxic and often more mobile than pen-tavalent compounds, while inorganic species are generally more toxic than organic ones. Local conditions, such as the redox potential, strongly influence its specification and thus potential bioavailability.
The introduction to this work elucidates the key factors which potentially cause human exposure to arsenic: the geological setting of the study area, land and water use pat-terns, and the current state of research regarding the mobilization, bioavailability and plant uptake of arsenic.
Although the study area is located in a region where the groundwater is known to be moderately contaminated by arsenic, the level of arsenic in the groundwater in the village had not previously been determined. In this study, water use in the village was examined by a survey among the farmers and by water analyses, which are present-ed in the following chapters. Four main water sources (rain, river, tube well and a pub-lic municipal waterworks) are used for the different daily activities; the highest risk to human health was found to be the bore well water, which is pumped from the shallow Holocene aquifer. The water from the bore wells is commonly used for cleaning and washing as well as to feed the animals and for food processing. Products like noodles and rice wine were examined as well as local pork and poultry. Vegetables from the gardens and rice plants from the surrounding paddy fields were sampled and ana-lyzed. All plants were found to have accumulated arsenic, leafy vegetables showing the highest arsenic concentrations.
The results are discussed and compared, and conclusions are drawn in the last part. The reducing conditions in the paddy fields are likely to have a strong influence on arsenic uptake in rice plants and on transport to the aquifer. The installation of a wastewater treatment plant under the research project INHAND, which was funded by the BMBF German Ministry of Education and Research, led to lower arsenic concen-trations in the groundwater.
Soaring industrialization, the growing population, and the consumers’ changing behav-ior will widely affect land and water use and hence the potential mobilization of arse-nic. In order to mitigate further human exposure to arsenic, wastewater needs to be treated and the reducing conditions in the rice fields need to be decreased by means of enhanced cultivation methods.:Abstract III
Zusammenfassung V
Acknowledgements VII
Contents IX
List of abbreviations XIII
List of tables XVII
1 Scope of this work 1
2 Introduction 2
2.1 Geographical and geological setting of the study area 2
2.2 Hydrological situation 5
2.2.1 Surface water 5
2.2.2 Impact of human activities on surface water quality and distribution 6
2.2.3 Hydrogeology 7
2.3 Arsenic occurrence 7
2.3.1 Arsenic toxicity 8
2.3.2 Risk potential of arsenic in diet 10
2.4 Arsenic contamination in the groundwater resources of the Red River Delta 11
2.4.1 Occurrence and origin of arsenic in the Red River Delta 12
2.4.2 Mobilization processes 13
2.4.3 As mobilization in paddy fields 15
2.5 Arsenic occurrence in daily rural activities 16
2.5.1 Arsenic in soil 17
2.5.2 Arsenic in drinking water 19
2.5.3 Phytoaccumulation: Current state of research 20
2.5.4 Bioavailablity 22
2.5.5 Arsenic uptake in rice plants 23
2.5.6 Arsenic in meat and animal products 26
2.5.7 Arsenic uptake in golden apple snails 27
2.5.8 Processing: Wine and noodles 28
2.5.9 Arsenic concentrations in wastewater, activated sludge and digestate 29
2.6 Iron and manganese in the nutrient chain 30
2.7 Land and water use in the Red River Delta 31
2.7.1 Historical and political aspects of rural development in Vietnam 33
2.7.2 Craft villages in the Red River Delta 34
3 Materials and methods 36
3.1 Soil sample analyses 36
3.2 Well sampling 37
3.3 Wastewater and sludge analyses 37
3.4 Food analyses 38
3.5 Site visit and field observations 39
3.6 Questionnaire 39
4 Results 40
4.1 Soil samples 40
4.1.1 Total arsenic and total heavy metal concentrations 40
4.1.2 Sequential fractionation procedure 41
4.2 Arsenic in the water cycle in Dai Lam 43
4.2.1 Groundwater analyses 43
4.2.2 Water use in Dai Lam 47
4.2.3 Wastewater in Dai Lam 50
4.3 Arsenic in sewage sludge 51
4.4 Arsenic in manure samples 52
4.5 Arsenic in food samples 52
4.5.1 Rice 52
4.5.2 Arsenic in leaf vegetables 53
4.5.3 Arsenic in poultry products 56
4.5.4 Arsenic in pork samples 57
4.5.5 Arsenic in snails 57
4.6 Economic and demographic development potential 58
5 Discussion 61
5.1 Soil samples 61
5.2 Groundwater samples 62
5.2.1 High arsenic concentrations 62
5.2.2 Strong temporal and spatial variation 63
5.2.3 Weak correlation between measured parameters 69
5.3 Wastewater and sewage sludge 70
5.4 Pig manure 71
5.5 Daily exposure to As from dietary intake 71
5.6 Effects of land and water use on water quality and public health 76
5.7 Against the background of the transition economy 77
6 Conclusion 80
7 Perspectives (further work) 85
8 References 86
9 Annex 110
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Research to Inform the Management of Protected Natural AreasCarr, Christopher January 2014 (has links)
No description available.
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Vegetation dynamics and response to disturbance of floodplain forest ecosystems with a focus on lianasAllen, Bruce Peter 06 June 2007 (has links)
No description available.
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Les enjeux territoriaux contemporains de l’endiguement en milieu urbain : L’évolution des rives du fleuve Rouge à Hanoï / The contemporary territorial wagers of urban dyke embankment : Revolution of the riverside of Red river, HanoiLe, Ha Phong 30 November 2016 (has links)
L’objectif de cette recherche est d’analyser les caractéristiques de la relation entre les villes et leurs fleuves, ainsi que les transformations des zones riveraines sous l’effet de l’urbanisation, avec le cas d’études de Hanoï et le fleuve Rouge, qui est représentatif de cette relation des pays du sud-est asiatique. Ce fleuve est la base importante de l’installation des Vietnamiens, de l’évolution des zones riveraines et de la forme urbaine de Hanoï. Sa relation avec cette ville est structurée par des caractères contradictories. Le fleuve offre la ville des opportunités, mais la menace par un risque d’inondations : tout d’abord, il contribue à développer l’agriculture en alimentant la ville en eau et alluvions, effectue un axe de transport fluvial important et constitue la forme d’une ville au milieu des eaux. Mais ses crues sont toujours un péril persistant de la ville. Au long de l’histoire, les habitants ont cherché à s’adapter au courant du fleuve. La construction et l’évolution de la digue est l’exemple de cette adaptation. La digue protège la ville contre les inondations, mais la sépare en deux parties. Cette séparation entraîne beaucoup de problèmes. Sous l’urbanisation et en raison du manque d’un cadastre d’autorités, les zones densément peuplées hors digue au centre ville et les nouveaux quartiers riverains du sud se transforment rapidement. Donc, une recherche pluridisciplinaire a été effectuée pour analyser le processus et les conséquences de ces transformations. Dans le contexte de la « nouvelle capitale » depuis 2008 et de son schéma directeur pour le développement de 2030, avec plusieurs stratégies du développement, l’étalement urbain et la migration vers le centre ville, cette recherche s’appuie particulièrement sur l’évolution économique suite aux changements administratifs, les questions foncières, les transformations des infrastructures et leurs conséquences environnementales des nouveaux quartiers ; les problèmes sociaux et démographiques des zones centrales où concentrent un grand nombre de migrants ; l’hésitation entre la préservation des valeurs architecturales et la modernité des villages de métiers. Enfin, la thèse cherche à analyser aussi les impacts de ces transformations sur le développement urbain de Hanoï, surtout au niveau du paysage et de la technique urbaine. / This thesis is aimed to analyze the characteristics of the relation between cities and rivers, and also the transformations of riverine zones under urbanization, with the case study of Hanoi and Red river, which is typical of this relation in Southeast Asia. Red river is an important base of Vietnamese’s settlement, the evolution of the riverine zones and urban water form of Hanoi. Its relation with the city is built by some contrary characteristics. The river brings the city opportunities, but also threatens it with a risk of inundation: firstly, the river contributes to the development of agriculture by bringing water and depositing alluvium on the riverbank; it also creates an important fluvial traffic and make up the city’s form. However, flood from the river is always a persistent peril. Throughout the history, the inhabitants have been seeking to cohabit with the river. The construction and the evolution of the dyke is a typical example of this process. The dyke prevents the river from flooding the city, but it also divides the city into 2 parts. This separation brings on many problems. Under pressure of urbanization and lack of land register, the densely populated outside-dyke zones in city center and the new urban quarters in the South are transforming rapidly. Accordingly, an interdisciplinary research was carried out in order to analyze the process and the consequences of these transformations. In the context of a « new capital » from 2008 and its master plan for 2030 with many development strategies concerning urban expansion and the migration towards the city center, this research focus on economic evolution, land dispute, transformations of the system of urban infrastructure and their environmental consequences in the new riverine urban quarters, social problems in the central zones where concentrated by a lot of immigrants, the hesitation between modernity and tradition in the handicraft villages. Finally, this thesis is aimed to analyze the contrary impacts of these transformations to urban development of Hanoi, especially in landscape and in urban infrastructure.
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An Exploration of the Selkirk TreatyHasselstrom, Nathan 04 April 2019 (has links)
In 1817, the fifth Earl of Selkirk and certain Saulteaux chiefs negotiated the Selkirk Treaty to secure the existence of a fragile Euro-Canadian settlement near the confluence of the Red and Assiniboine Rivers. Selkirk died soon after, and his agents and successors disputed the content of the treaty with the Indigenous negotiating parties. The historiography of the Selkirk Treaty has not reached a consensus on these disputes, in part due to the number of ostensibly contradictory sources it draws upon. This thesis argues that these disputes can be best answered, and these ostensibly contradictory sources best reconciled, by situating them and the Selkirk Treaty within the context of the Indigenous and Imperial land frameworks that operated in Red River in 1817.
This thesis first identifies unresolved questions in the historiography of the Selkirk Treaty. Using primary sources cited in the historiography, it then outlines the ideas acting within the Indigenous and Imperial land frameworks operative over Red River. It argues these ideas and frameworks remained intact during the negotiation of the Selkirk Treaty. On the basis of these frameworks, this thesis further argues that neither Lord Selkirk nor the Saulteaux negotiators intended the Selkirk Treaty to consist of a permanent alienation of Indigenous land. However, after Selkirk’s death, his agents and successors came to trust the Indenture of the Selkirk Treaty, a written and signed record of the treaty, as the only trustworthy record of the agreement. Selkirk’s agents and successors then read the Indenture as a permanent alienation of land, but this thesis argues that, on the basis of the borders specified in the Indenture, that document alone is inadequate to interpret the Selkirk Treaty.
The primary purpose of this thesis is to provide a point of departure for future research into the Selkirk Treaty. At the same time, it is intended as a corrective against assuming the ideas of either Indigenous or Euro-Canadian actors about land rights in colonization zones. It is also meant to act as a caution against relying any more heavily on the Indenture of the Selkirk Treaty than scholars do on the written records of other treaties. It is further hoped that this thesis contributes to a better understanding of Red River’s Métis population in these early years by situating them within the framework of the broader Iron Alliance.
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Water First : a political history of hydraulics in Vietnam's Red River DeltaSmith, S. Andrew Enticknap, ANDREW_SMITH@acdi-cida.gc.ca January 2002 (has links)
Between 1961 and 1976 Häi Hung province -- present day Häi Duong and Hung
Yên -- lost the equivalent of two entire districts of agricultural land. How could so
much land be abandoned under a collectivised agriculture system? And what role
did poor water control infrastructure play in creating such a situation?¶
I answer these questions by examining the historical patterns of hydraulic
development in northern Vietnam from the beginning of the 19th century until the
introduction of the Production Contract system in 1981. Underlying both the
French colonial and communist visions of modernity and economic development
was a belief that improving agricultural productivity, of which large-scale hydraulic
infrastructure was an important component, could catalyse growth in the rural
economy, which could then finance industrialisation. I argue throughout this thesis
that developing large-scale hydraulic infrastructure in the Red River delta has relied
upon the creation of a hydraulic bargain between the state and water users. This is
in contrast to Wittfogel's theory of the hydraulic state, insofar as developing
hydraulic infrastructure has depended upon the active political and economic
participation and support of water users, and not the absolute power of the state.
The political economic history of the hydraulic bargain highlights the relative
power of peasants to influence the direction of large-scale hydraulic development
and, as such, the shape of the Red River delta's wet-rice economy.
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