Charging of the Penglai 9-1 oil field,Bohai Bay basin,China: Functions of the delta on accumulating petroleum     

《Marine and Petroleum Geology》2014

The Penglai 9-1 (PL9-1) oil field, which contains China's third largest offshore oil accumulation (in-place reserves greater than 2.28 × 10⁸ ton or 1.49 × 10⁹ bbl), was found in shallow reservoirs (700–1700 m, 2297–5577 ft) within the most active fault zone in east China. The PL9-1 field contains two oil-bearing series, the granite intrusions in Mesozoic (Mz) and both the sandstone reservoirs in Neogene Guantao (Ng) and Neogene Minghuazhen (Nm) Formation. The origins of the PL9-1 field, both in terms of source rock intervals and generative kitchens, were determined by analyzing biomarker distributions for 61 source rock samples and 33 oil samples. The Mesozoic granite intrusions, which hold more than 80% of the oil reserves in the field, were charged in the west by oil generated from the third member (Es₃) of the Shahejie Formation in the Bodong depression. The Neogene reservoirs of the PL9-1 field were charged in the west by oil generated from the third member (Es₃) of the Shahejie Formation in the Bodong depression and in the south by oil generated from the first member (Es₁) of the Shahejie Formation in the Miaoxibei depression. Interactive contact between the large fan delta and the mature source rocks residing in the Es₃ Formation of the Bodong depression resulted in a high expulsion efficiency from the source rocks and rapid oil accumulation in the PL9-1 field, which probably explains how can this large oil field accumulate and preserve within the largest and most active fault zone in east China.  相似文献   

Factors that influence the entry–exit decision and intensity of participation of fishing fleet for the Galapagos lobster fishery     

《Marine Policy》2014

The Galapagos Islands are a prime example of a place where fishery management policies have been established without first understanding the behavior of fishermen. Since the creation of the Galapagos Marine Reserve in 1998, there has not been a single study in the archipelago that investigates fishing behavior and the factors affecting this behavior. This paper addresses this gap in the literature by describing and analyzing the decisions of the fishing fleet for the red spiny lobster fishery. It focuses on factors that affect the short-term decisions regarding both participation and intensity of participation in the lobster fishery. This paper finds that the fishing fleet in the Galapagos Islands behaves as profit maximizing firms, because they consider all the benefits and costs that affect both their participation decision as well as their decision about how frequently to be active after they have decided to participate. The results also show that there is a large latent effort in the lobster fisheries that could threaten the sustainability of any initiatives aimed at increasing catchability, prices, or markets. It is expected that this analysis will be valuable to policy makers when designing or improving the management plans for Galapagos fisheries.  相似文献   

基于C5.0决策树算法的元胞自动机的洪河湿地演化模拟     

于振华  万鲁河 《测绘与空间地理信息》2014,(5):22-24

以洪河自然保护区1992年、2001年、2010年三期TM遥感影像为数据源,利用C5.0决策树算法从已有的数据及其影响因子数据中挖掘出洪河湿地的演变规则,并将获得的转换规则应用到元胞自动机模型中进行洪河湿地演变的动态模拟与预测,分析和探讨了元胞自动机模型在湿地景观模拟和预测中的重要作用。结果表明,在现有的空间变量和条件不变的情况下,在未来的洪河自然保护区湿地面积将减小,洪河自然保护区干旱化将加重。通过对湿地景观的动态变化模拟和预测研究,能够较好地反映湿地景观的动态变化情况。  相似文献   

Economic Value Evaluation of Wetland Service in Yeyahu Wetland Nature Reserve,Beijing     

ZHU Lin  CHEN Yun  GONG Huili  JIANG Weiguo  ZHAO Wenji  XIAO Yanfang 《中国地理科学(英文版)》2011,(6)

Based on multi-source data,this paper evaluated the economic value of ecological services in the Yeyahu Wetland Nature Reserve,Beijing,China.The ecological services of wetland included gas regulation,water quality im-provement,biodiversity maintenance,erosion control,water supply,recreational opportunity,raw material supply and existence value.Multiple conventional evaluation methods were used to calculate the value of eight wetland services.The results showed that significant values came from biodiversity ...  相似文献   

Precipitation impacts on mule deer habitat use in the chihuahuan desert of Mexico     

J.P. Esparza-Carlos  J.W. Laundré  V.J. Sosa 《Journal of Arid Environments》2011,75(11):1008-1015

In arid lands, food resources and predation risk become major decision factors in mule deer habitat use. We examined variables related to these two factors that might determine mule deer (Odocoileus hemionus) habitat use in a warm desert at two spatial scales: the macro-habitat scale, which relates to home range decisions, and the micro-habitat scale, which relates to decisions made during foraging. Our prediction was that habitat use should primarily be explained by food variables and, to a lesser degree, by variables related to predation risk by pumas (Puma concolor). We mapped all deer pellet groups in 72, 1 ha quadrats in the Mapimí Biosphere Reserve and measured food and habitat variables over two years with different precipitation amounts. The area was used more intensively during the dry year. Under drier conditions, deer habitat use was explained primarily by food resource variables and secondarily by variables related with predation risk. During the wetter year, food resources became unimportant while cover and visibility explained deer habitat use. The data suggest that the tradeoffs deer are willing to make between food resources and predation risk in an arid environment are strongly affected by food resource levels, as influenced by precipitation.  相似文献   

哈巴雪山自然保护区垂直气候带划分研究     

苏骅  王平 《云南地理环境研究》2011,23(1):47-51

依据哈巴雪山自然保护区及附近气候观测资料,应用气候学方法和原理,综合分析该自然保护区垂直气候要素,分析中发现,光照、气温、降水等气候要素,随海拔升高,垂直分异明显。依据气候特征的垂直变化,结合植被及土壤的分布,参照划分垂直气候带的标准,将保护区划分为7种气候带：河谷中亚热带、河谷北亚热带、山地暖温带、山地中温带、山地寒温带、高山寒带、高山永久冰雪带。分析结果表明：保护区垂直气候带特征分异明显,气候类型丰富多样;山地寒温带、高山寒带等地区,生态高度敏感脆弱。  相似文献   

Impact assessment and protection of outstanding landscape integrity in a natural heritage site: Fairy valley, Kanas Nature Reserve, Xinjiang, China   总被引：1，自引：0，他引：1  

Fang Han  Zhaoping Yang  Xinyu Liu  Feng Di 《山地科学学报》2011,8(1):46-52

The essential purpose of the Convention Concerning the Protection of World Cultural and Natural Heritage is to protect the integrity of heritage values. Outstanding landscape is the core embodiment of the aesthetic value of a natural heritage site. This paper proposes a new assessment method from the point of view of the protection of heritage values. It is used to measure the degree of outstanding landscape integrity under the human and natural impact in natural heritage sites. This paper employ three indices, a visual index of outstanding landscape, a harmony index of the artificial landscape and a disturbance index of damaged landscape, to measure the impact of landscape integrity. The impact assessment model is based on a weighted combination of the three indices. The study site is the Fairy Valley, Kanas Nature Reserve, Xinjiang Uygur Autonomous Region in northwest China. The information employed is derived from field investigation and a Digital Elevation Model (DEM). A comprehensive evaluation of the Fairy valley was undertaken and it was determined that the outstanding landscape values are being compromised. Three protection methods are proposed to reduce the adverse effects and maintain landscape quality, thereby providing site managers with suggestions for the protection of natural heritage values. More broadly, the paper contributes novel methods of landscape assessment applicable to natural protected areas.  相似文献   

河北唐海湿地和鸟类自然保护区的管理现状及保护对策     

杜卫军  袁东芹  鄂华  张娜 《湿地科学与管理》2011,7(2):36-38

介绍了唐海湿地和鸟类省级自然保护区的主要保护对象和管理现状,分析了保护区在保护和管理方面存在的问题和矛盾,从政策法规、加强执法、筹集资金和引进人才等方面提出了保护区的保护和可持续发展对策。  相似文献   

Lipids and pigments in deep-sea surface sediments and interfacial particles from the Western Crozet Basin     

Laurence Pinturier-Geiss  Jeanne Laureillard  Catherine Riaux-Gobin  Joëlle Fillaux  Alain Saliot   《Marine Chemistry》2001,75(4)

Deep-sea sediment samples were collected in the Western Crozet Basin (Indian sector of the Southern Ocean) through Permanently Open Ocean Zone (POOZ), Polar Frontal Zone (PFZ) and Sub-Antarctic Zone (SAZ). Lipid class and fatty acid compositions were investigated to determine the sources and fate of organic matter in the first centimeter of sediment and, above this layer, in the fluff (when present) and particles in the overlying water. The total lipid content varied from 74 to 1033 μg l⁻¹ in the overlying particles and fluffs, and from 24 to 97 μg g⁻¹ dry mass (DM) in surficial sediments. Lipid composition was always dominated by phospholipids in the first centimeter of sediment and often in the overlying particles. The amount of phospholipids (labile compounds representative of fresh material) was compared to the amount of chlorophyll a (Chl a), another compound that is susceptible to rapid degradation. A strong N–S gradient was observed in the distribution of these two compounds, which was attributed to the contrasting hydrodynamic of the study area. The high sedimentation rate in POOZ resulted in better preservation of Chl a in this zone than in other zones of the Crozet Basin (PFZ and SAZ). Phospholipid fatty acids suggested the presence of viable as well as morphologically intact organisms, and these organisms consisted essentially of bacteria with some diatom cysts in the fluff of POOZ. These spores were able to grow in the culture, indicating that they were still viable. Despite the strong hydrodynamic variability, phospholipid fatty acids analysed from the deep-sea surficial sediments were never representative of plankton. This pointed to the extremely labile nature of the phospholipids originally present in planktonic material compared with Chl a, which was always found in overlying particles and surficial sediments.  相似文献   

Assessment of the hydrological status of Doñana dune ponds: a natural World Heritage Site under threat     

A. Fernández-Ayuso  M. Rodríguez-Rodríguez  J. Benavente 《水文科学杂志》2013,58(15-16):2048-2059

ABSTRACT

The hydrological response of shallow ponds to groundwater withdrawal has been of growing concern in the Doñana National Park (southern Spain) in recent decades. This study examines the role of groundwater in maintaining the hydroperiod (i.e. the hydrological regime) in the park’s main dune ponds, by quantifying the groundwater fluxes to/from them. The hydrological characterization was performed by applying different methodologies. Daily hydrological balances registered in the ponds revealed groundwater contributions ranging from 80% of the total water inflows (i.e. groundwater discharge) to a net groundwater recharge from the ponds to the aquifer, and enabled the studied water bodies to be classified as discharge or recharge systems. The recharge systems must have been influenced by the lowering of piezometric levels due to groundwater extraction for urban supply in a nearby coastal resort.  相似文献