The micromechanisms of power in local content requirements and their constraints on Ghanaian SMEs in the oil and gas sector

Local content laws have the potential to promote positive synergies between the extractive sectors and African economies. However, their success is a negotiated outcome of interaction between actors. The objective of the article is to emphasize the mechanisms by which local content requirements are negotiated between actors in Ghana’s oil and gas industry, by drawing on Foucault’s concept of power. Data for the study were obtained through interviews, observations and secondary sources. The author found that complex registration systems, administrative details, and financial and technological requirements constituted the micromechanisms of power at play in determining how the local content law was applied in practice. The article demonstrates how these factors limit the activities of small and medium-scale enterprises (SMEs) in the oil and gas sector. The author concludes that the institutional context, the capacity of local SMEs, and the techniques and practices of multinational corporations (MNCs) shape the extent of local participation in Ghana’s oil and gas industry.     

Growth,dynamics and deglaciation of the last British–Irish ice sheet: the deep-sea ice-rafted detritus record

The evolution and dynamics of the last British–Irish Ice Sheet (BIIS) have hitherto largely been reconstructed from onshore and shallow marine glacial geological and geomorphological data. This reconstruction has been problematic because these sequences and data are spatially and temporally incomplete and fragmentary. In order to enhance BIIS reconstruction, we present a compilation of new and previously published ice-rafted detritus (IRD) flux and concentration data from high-resolution sediment cores recovered from the NE Atlantic deep-sea continental slope adjacent to the last BIIS. These cores are situated adjacent to the full latitudinal extent of the last BIIS and cover Marine Isotope Stages (MIS) 2 and 3. Age models are based on radiocarbon dating and graphical tuning of abundances of the polar planktonic foraminifera Neogloboquadrina pachyderma sinistral (% Nps) to the Greenland GISP2 ice core record. Multiple IRD fingerprinting techniques indicate that, at the selected locations, most IRD are sourced from adjacent BIIS ice streams except in the centre of Heinrich (H) layers in which IRD shows a prominent Laurentide Ice Sheet provenance. IRD flux data are interpreted with reference to a conceptual model explaining the relations between flux, North Atlantic hydrography and ice dynamics. Both positive and rapid negative mass balance can cause increases, and prominent peaks, in IRD flux. First-order interpretation of the IRD record indicates the timing of the presence of the BIIS with an actively calving marine margin. The records show a coherent latitudinal, but partly phased, signal during MIS 3 and 2. Published data indicate that the last BIIS initiated during the MIS 5/4 cooling transition; renewed growth just before H5 (46 ka) was succeeded by very strong millennial-scale variability apparently corresponding with Dansgaard–Oeschger (DO) cycles closely coupled to millennial-scale climate variability in the North Atlantic region involving latitudinal migration of the North Atlantic Polar Front. This indicates that the previously defined “precursor events” are not uniquely associated with H events but are part of the millennial-scale variability. Major growth of the ice sheet occurred after 29 ka with the Barra Ice Stream attaining a shelf-edge position and generating turbiditic flows on the Barra–Donegal Fan at ～27 ka. The ice sheet reached its maximum extent at H2 (24 ka), earlier than interpreted in previous studies. Rapid retreat, initially characterised by peak IRD flux, during Greenland Interstadial 2 (23 ka) was followed by readvance between 22 and 16 ka. Readvance during H1 was only characterised by BIIS ice streams draining central dome(s) of the ice sheet, and was followed by rapid deglaciation and ice exhaustion. The evidence for a calving margin and IRD supply from the BIIS during Greenland Stadial 1 (Younger Dryas event) is equivocal. The timing of the initiation, maximum extent, deglacial and readvance phases of the BIIS interpreted from the IRD flux record is strongly supported by recent independent data from both the Irish Sea and North Sea sectors of the ice sheet.     

Benchmarking sustainability in cities: The role of indicators and future scenarios

Scenarios are a useful tool to help think about and visualise the future and, as such, are utilised by many policymakers and practitioners. Future scenarios have not been used to explore the urban context in much depth, yet have the potential to provide valuable insights into the robustness of decisions being made today in the name of sustainability. As part of a major research project entitled Urban Futures, a toolkit has been developed in the UK to facilitate the use of scenarios in any urban context and at any scale relevant to that context. The toolkit comprises two key components, namely, (i) a series of indicators comprising both generic and topic area-specific indicators (e.g., air quality, biodiversity, density, water) that measure sustainability performance and (ii) a list of characteristics (i.e., 1–2-sentence statements about a feature, issue or small set of issues) that describe four future scenarios. In combination, these two components enable us to measure the performance of any given sustainability indicator, and establish the relative sensitivity or vulnerability of that indicator to the different future scenarios. An important aspect of the methodology underpinning the toolkit is that it is flexible enough to incorporate new scenarios, characteristics and indicators, thereby allowing the long-term performance of our urban environments to be considered in the broadest possible sense.     

Land cover and land use change related to shrimp farming in coastal areas of Quang Ninh,Vietnam using remotely sensed data

Rapid development of shrimp farming may lead to unrecognized and undesirable changes of land cover/land use patterns in coastal areas. Of special concern is the loss of mangrove forest in coastal areas such as Quang Ninh, Vietnam, which is adjacent to the World Heritage-listed Ha Long Bay. Understanding the status and changes of land cover/land use for coastal shrimp farms and mangrove forests can support environmental protection and decision-making for sustainable development in coastal areas. Within this context, this paper uses the 1999/2001 Landsat ETM+ and the 2008 ALOS AVNIR-2 imagery to investigate the contraction and expansion of shrimp farms and mangrove forests in coastal areas of Ha Long and Mong Cai, which now have a high concentration of intensive and semi-intensive shrimp farms. Images were separately analyzed and classified before using post-classification comparisons to detect land cover/land use changes in the study area. The results of this study found that the area of mangrove forest has been reduced by an estimated 927.5 ha in Ha Long and 1,144.4 ha in Mong Cai, while shrimp farming areas increased by an estimated 1,195.9 and 1,702.5 ha, respectively, over the same period. The majority of shrimp farms in Mong Cai were established at the expense of mangrove forest (49.4 %) while shrimp farms in Ha Long were mainly constructed on areas previously occupied by bare ground (46.5 %) and a significant proportion also replaced mangroves (23.9 %). The remarkable rate of mangrove loss and shrimp farming expansion detected in this study, over a relatively short time scale indicate that greater awareness of environmental impacts of shrimp farm expansion is required if this industry is to be sustainable, the important estuarine and coastal marine ecosystems are to be protected over the long term, and the capturing and storing of carbon in mangrove systems are to be enhanced for global climate change mitigation and for use as carbon offsets.     

Identifying sources of groundwater in the lower Colorado River valley, USA, with δ18O, δD, and 3H: implications for river water accounting

Isotope measurements (¹⁸O, D, ³H) indicate groundwater origin in the Lower Colorado River Valley (LCRV) and provide an alternative, or supplement, to the US Bureau of Reclamations proposed accounting surface method. The accounting surface method uses a hydraulic criterion to identify certain wells away from the flood plain that will eventually yield mainstream Colorado River water. New isotope data for 5 surface-water and 18 groundwater sites around Topock Marsh, Arizona, are compared with river-water data (1974–2002) from 11 sites between Utah and Mexico and with groundwater data from previous LCRV studies. Three groundwater sources are repeatedly identified in the LCRV: (1) local recharge derived from precipitation, usually winter rain, plots slightly below the global meteoric water line (GMWL) and has D values that are 20 greater than those of recent river water; (2) older (pre-1950) upper basin river-water plots on or near the GMWL, distinct from local rainfall and recent river water; and (3) recent (post-1950) Colorado River water, including Topock Marsh samples, plots below the GMWL along an evaporation trend. Large floods, as in 1983, complicate interpretation by routing less evaporated upper basin water into the LCRV; however, tritium content can indicate the age of a water. River-water tritium has declined steadily from its peak of 716 TU in 1967 to about 11 TU in 2002. Mixtures of all three groundwater sources are common.

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Resumen Mediciones isotópicas (¹⁸O, D, ³H) indican cual es el origen del agua subterránea en el Valle Bajo del Río Colorado (LCRV) y aportan una alternativa, o complemento, para el método superficie de conteo propuesto por el Buró de Reclamación de Estados Unidos. El método superficie de conteo utiliza un criterio hidráulico para identificar ciertos pozos alejados de la planicie de inundación que eventualmente producirán agua a partir de la corriente principal del Río Colorado. Los nuevos datos isotópicos para 18 sitios de agua subterránea y 5 sitios de agua superficial cerca de los Pantanos Topock, Arizona, se comparan con datos de agua de río (1974–2002) provenientes de 11 sitios localizados entre Utah y México, y con datos de aguas subterráneas de estudios previos realizados en el LCRV. Se identifican reiteradamente tres fuentes de aguas subterráneas en el LCRV: (1) recarga local derivada de precipitación, generalmente lluvia de invierno, cuya composición cae ligeramente por debajo de la línea de agua meteórica global (GMWL) y tiene valores D que son 20 mayores que los reportados para agua de río reciente; (2) el agua de río más vieja (pre-1950) de la cuenca alta cuya composición cae sobre o cerca de la GMWL, diferente de la lluvia local y del agua de río reciente; (3) agua reciente (post-1950) del Río Colorado, incluyendo muestras de los Pantanos Topock, con composición por debajo de la GMWL a lo largo de una tendencia a la evaporación. Inundaciones grandes, como en 1983, complican la interpretación al transmitir menos agua evaporada de la cuenca alta hacia el LCRV; sin embargo, el contenido de tritio puede indicar la edad del agua. El contenido de tritio en agua de río ha disminuido constantemente desde la concentración pico de 716 TU en 1967 a cerca de 11 TU en 2002. Es común que exista mezclas de las tres fuentes de agua subterránea.

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Résumé Les mesures isotopiques (d18O, dD, 3H) indiquent les origine de leaux souterraines dans la Vallée de la Rivière du Bas Colorado (LCRV) et sont une alternative, ou un supplément, à la méthode des bilans hydrologiques proposée par du «US Bureau of Reclamation». Cette méthode de bilan hydrologique utilise un critère hydraulique permettant didentifier certains puits hors de la plaine dinondation qui pomperaient une part non négligeable de leur eau dans la rivière Colorado. De nouvelles données isotopiques provenant de 5 sites deau de surface et 18 deaux souterraines autour de Topock Marsh en Arizona, sont comparées avec les données (1974–2000) de 11 sites localisés entre Utah et Mexico, ainsi que des données dautres études sur la LCRV. Ces sources deaux souterraines sont identifiées à plusieurs reprises dans la LCRV: (1) la recharge locale dérivant des précipitations, généralement les pluies hivernales, se retrouvent légèrement sous la ligne deau météoritique globale (GMWL) et possède des valeurs de dD 20% supérieures aux valeurs des eaux récentes de la rivière; (2) les eaux vieilles (pre-1950) du bassin supérieur de la rivière possèdent une valeurs très proches de la GMWL, distinctes des valeurs de la pluie locale et des eaux récentes de la rivière; et (3) les eaux récentes (post-1950) de la Rivière Colorado, incluant les échantillons de Topock Marsh, se positionnent à côté de la GMWL sur une droite dévaporation. Les grandes inondations, par exemple celle de 1983, compliquent linterprétation en reprenant dans la LCRV moins deaux marquées comme évaporées et provenant du bassin supérieur; par ailleurs le pic de tritium est descendu de 716 TU en 1967 à 11 TU en 2002. Les mélanges de ces trois sources sont assez fréquentes.

     

A case study of GATE convective activity

Abstract

This paper presents the synoptic and meso‐scale aspects of the intense convective activity of 2 September 1974 in the Eastern Atlantic. Two main features were evident in the GATE B‐scale array: a broad convective band associated with the 700‐mb trough, and long and narrow lines of convection oriented SE‐NW. One of these lines, which moved across the B‐scale array and was penetrated by several aircraft, is described in detail. The structure of the cloud and precipitation fields, obtained from the analysis of satellite and radar data, indicates that intense precipitation occurred mainly at the leading edge of the line where new cells were continuously generating. Cross‐sections through the line (from boom, aircraft and tethered balloon data) show a gust front at the surface, a downdraft region associated with the rain area, and a wind shift in the lowest 300 m. The circulations around and within this line appear to be similar to a class of tropical squall‐lines studied at length by Zipser, (1977) and Houze (1977) with the important difference that the horizontal gradients of the dynamic and thermodynamic variables across the line were typically weaker.