首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7篇
  免费   0篇
地球物理   2篇
地质学   3篇
海洋学   2篇
  2019年   1篇
  2012年   1篇
  2010年   1篇
  2009年   1篇
  2003年   1篇
  2002年   2篇
排序方式: 共有7条查询结果,搜索用时 968 毫秒
1
1.
The Gulf of Guinea is situated in the narrow protrusion of eastern Equatorial Atlantic between latitudes 2 degrees S and 5 degrees N and longitudes 8 degrees W to 12 degrees E, spanning a coastline length of approximately 130 nautical miles. The dominant feature of this shallow ocean off the coast of countries in Western Africa is the Guinea Current. The distinctive bathymetry, hydrography, productivity and trophodynamics of this shallow ocean qualify it as a large marine ecosystem (LME) and is indeed recognized as the number 28 of the 64 delineated LMEs globally. This area is one of the world's productive marine areas that is rich in fishery resources, oil and gas reserves, precious minerals and an important global reservoir of marine biological diversity. Unfortunately, pollution from residential and industrial sources has affected the waters of the Gulf of Guinea resulting in habitat degradation, loss of biological diversity and productivity, and degenerating human health. In reversing this trend of marine environmental degradation, the countries of the region adopted an integrated and holistic approach using the LME concept to sustainably manage the environmental and living resources of the region. The concept is predicated on the fact that marine environmental pollution and living resources respect no political or geographical boundaries and so require a holistic and regional approach for its management. The Gulf of Guinea countries through the Global Environment facility funded regional/communal project on water pollution control and biodiversity conservation achieved a paradigm shift in living resources and environmental management in the region using the LME concept.  相似文献   
2.
Acta Geochimica - Petrographic studies on Granitoids from Katchuan Irruan and adjoining areas, southeastern Nigeria, has shown that they are garnetiferous biotite granite, aplitic granite,...  相似文献   
3.
Environmental pollution in the Gulf of Guinea (GOG) coastal zone has caused eutrophication and oxygen depletion in the lagoon systems, particularly around the urban centres, resulting in decreased fish (reproduction) levels and waterborne diseases. A pollution sources assessment was undertaken by six countries in the region as a first step in defining a region-wide Environmental Management Plan. Results show that households produce 90% of solid waste. Industry, however, is responsible for substantial amounts of hazardous waste, specifically the Nigerian petroleum industry. The latter is also responsible for the spilling of large amounts of oil. BOD load from industrial effluents is slightly larger than domestic loads in the industrialised coastal zone. Wastewater treatment systems are either absent or inadequate. Apart from large-scale gas flaring in Nigeria, air pollution, in terms of COx, HC, NOx and SO2 emissions, is contributed mainly by traffic. Particulates, originate mainly from industries and domestic biomass burning.  相似文献   
4.
The Guinea Current Large Marine Ecosystem extending from Guinea Bissau to Angola and covering sixteen countries in West and Central Africa and characterized by distinctive bathymetry, hydrography, chemistry, and trophodynamics with the Guinea Current as the unifying feature has remained a sources of global interest. With openness to the Atlantic Ocean and watercourses with access to the sea such as the Congo and Niger Rivers, the GCLME embodies some of the major coastal upwelling sub-ecosystems of the world and is an important center of marine biodiversity and marine food production ranked among the most productive coastal and offshore waters in the world. However, pollution from domestic and industry sources, over-exploitation of fisheries and poorly planned and managed coastal developments and near-shore activities are resulting in a rapid degradation of vulnerable coastal and offshore habitats and shared living marine resources of the GCLME putting the economies and health of the populace at risk. The deterioration in water quality (chronic and catastrophic) from land and sea-based activities (especially industrial, agricultural, urban and domestic sewage run-off and mining activities including the oil and gas sector), eutrophication and harmful algal blooms have been identified as a major transboundary environmental problem by the countries in the adopted Transboundary Diagnostic Analysis (TDA). Arising from the results of the various environmental and socio-economic studies and assessments conducted over the years as documented in the Transboundary Diagnostic Analysis (TDA), the countries resolved to adopt a holistic, multi-sectoral and regional approach embodied in the large marine ecosystem concept for transboundary pollution management in the region. The agreed management actions to be undertaken jointly by the sixteen countries are encapsulated in the adopted Strategic Action Programme to be implemented by the Interim Guinea Current Commission (and later the Guinea Current Commission), established by the countries as an intergovernmental consultation and coordination body, with the technical assistance and co-funding of the Global Environment Facility (GEF), the United Nations Industrial Development Organization (UNIDO), United Nations Development Programme (UNDP) and United Nations Environment Programme (UNEP).  相似文献   
5.
This study is a first step towards valuing the Guinea Current Large Marine Ecosystem (GCLME), one of the five world's most productive marine areas that are rich in fishery resources, petroleum production, and an important global region of marine biological diversity. The area is highly degraded and thus demands urgent attention to recover and sustain depleted fisheries; restore degraded habitats; and reduce land and ship-based pollutions. Achieving this goal would be a mirage if the actual value of the ecosystem's contribution to the society is not known. Valuation can help identify the main beneficiaries of conservation and the magnitude of benefits they receive, and help design measures to capture some of these benefits and contribute to financing of conservation. Hence this study used the direct output approach to estimate the value of relevant marine activities in the area. The result shows that the total value of output in GCLME when some outputs namely, marine fishery, offshore oil production, NTFP (periwinkle) and mining, are considered as $49,941.4 million. Among these uses, offshore oil production has the highest value accounting for 59.79% of the total estimate. These estimates provides sufficient evidence to show that GCLME provide enormous value and should be managed appropriately to sustain the gains if the economic development would be guaranteed especially considering that most countries in the GCLM depend on natural resources for their survival. Evolving a well defined property rights regime and an efficient governance system for management is recommended.  相似文献   
6.
The concentrations of total polycyclic aromatic hydrocarbons (??PAHs) and 16 individual PAH compounds in 6 surface water and 44 soil samples collected from the vicinity of spilled fuel from a pipeline which carries fuel from a jetty to the tank farm were analyzed. The ??PAHs concentrations in surface water ranged from 0.37 to 99.30?mg/l with a mean concentration of 57.83?mg/l. The ??PAHs concentrations in water are of several orders of magnitude higher than in unpolluted water and some national and international standards including in some surface water in other parts of the world. This suggests that the surface water of the area were heavily polluted by anthropogenic PAHs possibly from the spills. The total PAH concentrations in soil ranged from 16.06 to 25,547.75???g/kg with a mean concentration of 2,906.36???g/kg. ??PAH concentrations of the seven carcinogenic PAH compounds in soil varied between 0.02 and 97,954???g/kg. In terms of composition of patterns in surface water and soil, the PAHs were dominated by four and three rings. The distribution pattern showed marked predominance by low molecular weight compounds. In comparison with ??PAHs concentrations in other part of the world, the total PAH concentrations of this area were higher than those reported for some urban soils in some regions of the world. The ratios of Phe/Ant, Flu/Pyr, Flu/(Flu?+?Pyr), and BaA/(BaA?+?Chyr) in both water and soil indicated various sources of PAH in the area. These sources include fuel spills, burning of motor tyres and vegetation, vehicle repairs and washing, motor exhaust and fire wood burning from cooking.  相似文献   
7.
The Oramiriukwa River is within the sandy coastal plain strata of the Benin formation (Miocene–Recent). The base flow is very high ranging from 79.13–98.56%, which is caused by the excellent hydraulic interconnection between the river and the adjacent unconfined aquifer. Recharge rates are high, estimated to range from 1.8×1012–2.5×1012 m3/year. Coastal sands are medium-to-coarse grained, moderately-to-poorly sorted, angular to subangular, with lenses of clay and clayey fine-grained sands. The coastal sands and clay lenses form aquifer and aquitard systems, which are unconfined to semi-confined. Groundwater recharge potential is high. Runoff from precipitation is low. Groundwater and surface water are fairly acidic; pH ranges from 5.5–6.1 (groundwater) and 5.8–6.5 (surface water), and hardness is generally low. Chemical analysis and percentage sodium show that groundwater and surface water are somewhat potable after some pH modification of the surface water. The waters are good for agricultural use, especially for irrigation and poultry water supply. However, pollution from landfill leachate is serious. Electronic Publication  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号