Στα πλαίσια της πτυχιακής εργασίας με τίτλο « Παλαιοπεριβαλλοντική ανάλυση στο δέλτα του ποταμού της Νέδα», μελετήθηκε ένας πυρήνας γεώτρησης παρμένος από το δέλτα της. Μετά την ιζηματολογική ανάλυση του πυρήνα αυτού, καταλήξαμε στο συμπέρασμα πως η θέση μελέτης αποτέλεσε την κοίτη της αύλακας του ποταμού, η οποία στην εξέλιξή της στο χρόνο πληρώθηκε από ιζήματα μετά από διαδοχικά πλημμυρικά επεισόδια και πλέον αποτελεί μέρος της πλημμυρικής πεδιάδας της Νέδα, που συνεχίζει να ρέει έχοντας τώρα μεταναστεύσει πλησίον της θέσης λήψης του πυρήνα. / As part of the graduation project entitled "paleoenvironmental analysis in the delta of the river Neda" we studied a drilling core taken from the delta. After the grain analysis of this core, we concluded that the study location was the riverbed of the river channel, which in the evolution over time, was filled by sediments after a series of flood events and now, is part of the flood plain of Neda, which continues flowing having migrated to the vicinity of the location where the core was taken.

No description available.

No description available.

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.

This thesis examines the social character of petroleum-related grassroots struggles in Nigeria’s oil-producing region. It does this against the background of the dominant scholarly narratives that portray the struggles as: a) a disguised pursuit of an ethnic/sectional agenda, b) a 'minority rights' project, and c) a minority province’s protest against 'selective' environmental 'victimisation' by the majority ethnic nationalities. While the dominant scholarly analyses of the struggles are based on the activities of the better known activist organisations operating in the oil region, this thesis focuses primarily on the everyday 'grammar' of discontent and lived worlds of ordinary people vis-à-vis upstream petroleum operations and petroleum resource utilisation. The aim has been to gain an understanding of the forces driving community struggles in the oil region and their wider societal significance. Examined alongside the narratives of ordinary people are the legal/institutional framework for upstream petroleum operations and the operational practices of the oil-producing companies. Using primary data obtained through ethnography, focus group discussions, in-depth interviews and visual sociology, as well as relevant secondary data, the researcher constructs a discourse matrix, showing how grassroots narratives in selected oilproducing communities intersect with contemporary civic discourses in the wider Nigerian context. The thesis highlights the theoretical and policy difficulties that arise when the social basis of petroleum-related grassroots struggles and ordinary people’s narratives are explained using an essentialist idiom. It reveals, above all, the conditions under which so-called 'locale-specific' struggles in a multi-ethnic, oil-rich African country can become a campaign for the emancipation of ordinary people in the wider society. This research extends the existing knowledge on citizen mobilisation, extractive capitalism, transnational corporate behaviour, and Nigeria’s contemporary development predicament. It sheds light on some of the processes through which ordinary people are forcing upon the state a change agenda that could drive the country along a more socially sensitive development and democratisation trajectory.

Economic valuation of the Okavango Delta can support decision making in a complex socio-economic environment in which economic development depends on a deep understanding of the value of biodiversity. The use of a natural resource accounting framework in determining the value of goods and services is crucial. The total economic value of the Okavango Delta was estimated by using primary (household valuation) and secondary data. A natural resource accounting framework was used. The components of the total economic value were the composition of wild herbivores and vegetation, and the functional values, which comprised direct use values of wild herbivores, river reed, thatching grass, wild fruits, fuelwood and palm leaves, indirect consumptive values of honey production, carbon sequestration, livestock grazing, milk production, non-consumptive use of tourism, and existence and bequest values. The values of the composition and function are expressed in per/ha values. The value of the composition of wild herbivores was estimated at P1 444 992 400 (US$ 294 850 699.2) or US$ 27.4/ha, while the functional value was estimated at P185 913 117.4 (US$ 37 527 840.96 or US$ 619.77/ha. Of the estimated direct use values of vegetation, river reed had the highest value of US$ 29.0/ha, while the highest value among indirect use values was that of milk production (US$ 8.5/ha). These values of selected resources reflect the contribution of the value of biodiversity of the Okavango Delta to the overall economy of the country and represent initial estimates of costs to society if these resources are lost. The estimated values can be used to raise awareness among decision makers of the economic benefits of conserving the Okavango Delta. Overall, the findings showed that the various components of the total economic value of the Okavango Delta were comparable to other wetlands in the region. / Thesis (PhD (Agricultural Economics))--University of Pretoria, 2006. / Agricultural Economics, Extension and Rural Development / unrestricted

Global economic integration and urbanisation are two of the main processes which characterise contemporary globalisation. Urbanisation is so pervasive that urban landscapes now stretch far beyond the traditional city limits such that the city may no longer be the most appropriate unit to reflect how contemporary urban life is organised. Today, city-regions even mega city-regions are considered by some to be the primary spatial scale at which competing political and economic agendas are convened. Moreover, proponents of the new regionalism believe that decentralisation of state power is producing new forms of political economic regulation at supranational and subnational levels which are more appropriate for effective governance. However, it is argued that the geoeconomic logic for city-regionalism is focused too narrowly on the functional economic side of regional development, thereby overlooking how city-regions represent geopolitical constructions both of, and inside, the state. This thesis therefore aims to explore the constitutive role of politics in the construction of mega city-regions. The starting point is to complement North Atlantic accounts of city-regionalism by focusing on the geopolitics of city-regionalism in China. Using the Yangtze River Delta mega city-region as its case study, this thesis stresses that theories of new city-regionalism must increasingly be derived from, rather than applied to, the Chinese case. It is revealed how the unprecedented rate of city expansion, scale of urbanisation, and context of a highly centralised, one-party state, produces a distinctly Chinese city-regionalism that requires a combination of new conceptualisation, alongside refinement and modification of existing theories on mega city-regions.

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

No description available.

Every thousand years or so, when the Mississippi River's sediment load lengthened and blocked the River’s route to the Gulf of Mexico, the mother stream changed course completely, finding a shorter route to the sea. Then, it built a new delta, thus spreading the gift of land creation along a wide coastline and creating the bayou region of Louisiana. However, this ancient, natural process was gradually halted by the arrival of man who settled across the River's natural floodplain (delta) and constructed levees and other structures to control the great Mississippi River. Since the 1930s, the Mississippi River Delta Basin and the coast of Louisiana have been literally losing ground. The decline of this environment is now affecting, and will continue to affect, our nation's economy, infrastructure, culture, and safety. Moreover, efforts to fix this problem are not working. My research and this thesis will address the issue of how plans without action have appeased Louisianans while the nation looses vital wetlands daily.