A probabilistic method for resource appraisal in a petroleum play and its application     

Jingzhen Xu  Xiaodong Liu  Zhangming Chen  Chunwen Gao 《Natural Resources Research》1997,6(4):277-280

A probabilistic method that is based upon conditional probability theory and the laws of expectation has been developed for estimating the undiscovered oil and gas resources in a petroleum play. It takes into account the favorable geological conditions that influence the accumulation of oil and gas and those factors which influence the distribution and the quantity of undiscovered oil and gas. Information about the number and size of undiscovered resources is provided. A practical application in the Turpan-Hami Basin in northwestern China is described. An erratum to this article is available at .  相似文献   

基岩裸露区金矿异常源的快速追踪与评价   总被引：1，自引：1，他引：0  

李应桂  杨少平  余学东  任天祥 《物探与化探》1997,21(1):37-49

在五台山古代、现代民采强烈污染区,水化学测量不仅能快速有效地圈定找矿靶区,而且可以排除人为污染。多子样组合"面型"岩石测量方法技术,与常规的点线式测量相比,不仅大大减少了样品采集和分析数量,大幅度降低了工作成本,而且更重要的是能快速有效地追踪区域化探异常源、评价区域化探异常找矿远景、圈定矿产详查找矿地段。试点测量结果表明,五台山地区矿化与燕山期中酸性杂岩体具有成因联系,其空间分布以杂岩体为中心具有Mo、Cu、Au-Cu、Pb、Zn-Au、Ag、Pb为主的多元素异常环带状分布模式;相应表征着斑岩矿化—接触交代矿化—岩浆期后热液矿化及其环带状分布。  相似文献   

Movement patterns of the sea urchin Paracentrotus lividus in a marine reserve and an unprotected area in the NW Mediterranean     

Bernat Hereu 《Marine Ecology》2005,26(1):54-62

Sea urchins can alter the composition and dynamics of algal communities by grazing. Changes in their displacement capability can influence their grazing and thus their effect on algal communities. The daily and monthly movement of Paracentrotus lividus inside and outside a marine reserve in the NW Mediterranean Sea was studied in order to determine the role of predation in sea urchin movements and its potential grazing impacts. During the 3‐month study, the total distance travelled by sea urchins ranged from 71.8 to 673.6 cm (mean = 379.2 cm, SD = 221.3). Home ranges (distances from the initial position) were between 50 and 302 cm (mean = 150.7 cm, SD = 99.4). Movements were not directional but random, with a mean of 150 cm around the initial position. The activity of Paracentrotus lividus was significantly higher at night than during daylight. Total displacement at the end of the experiment was significantly higher in the unprotected area than in the reserve, as was the home range. The linear distance travelled in a 24‐h period ranged between 6 and 220 cm with a mean home range of 51 cm. These results agree with those of other authors, and allow us to rule out major migratory processes of sea urchin populations in this area. Nevertheless, these results underline the role of predatory fishes in reducing herbivory pressure by trophic cascades, reinforcing the evidence that sea urchin escape behaviour may be an important factor in structuring algal communities.  相似文献   

基于[-1，1]线性变换算子的多指标灰色关联决策模型在工程项目评标中的应用     

王恕  张亦飞  曹玉泉  郝春玲 《海洋学研究》2005,23(4):49-53

建立了多指标灰色关联度工程项目评标决策模型。实际算例计算结果表明,该模型物理意义明确,与评标思维过程一致,比灰色关联投影法具有更高的分辩程度,有利于实际评标的操作。  相似文献   

重力数据处理方法在寻找油气田中的应用   总被引：1，自引：0，他引：1  

朱永盛  于舟 《中国海洋大学学报(自然科学版)》1994,(1)

提出重力数据处理方法技术在寻找油气田中的应用，讨论所采用的数据处理方法包括：趋势面分析、高阶导数、归一化总梯度、分离场法反演多层密度界面等的原理，并通过在多处地区试验和应用，对划分区域构造、圈定局部构造、计算沉积岩层的厚度以及对含油气远景进行评价。  相似文献   

Biological Evaluation of Marine ­Protected Area: Evidence of Crowding Effect on a Protected Population of Queen Conch in the Caribbean     

Christophe Béné  & Alexander Tewfik 《Marine Ecology》2003,24(1):45-58

Abstract This study provides a first evaluation of the biological impact of a marine fishery reserve on the stock of queen conch (Strombus gigas) in the Turks and Caicos Islands. The density and the shell length of the population living in the reserve are compared with those of the individuals living in the surrounding fished areas. The results show that the adult density is six times higher in the reserve than in the fished areas. The shell length analysis shows that both adults and juveniles are significantly smaller in the reserve than in the fished area. This unexpected result suggests the existence of a crowding effect (i. e. a high density‐induced reduction in growth rate) within the ­reserve. It is hypothesised that this crowding effect is due to the superimposition of two factors leading to very high density values in the reserve: (a) the reduced fishing mortality following the creation of the reserve, (b) the existence of natural barriers that impede the emigration of adults outside the reserve. These results are then discussed in relation to current considerations on marine fisheries reserves.  相似文献   

限制性克立格法在阿舍勒铜矿储量计算中的研究与应用     

孙刚  徐兵  韩燕 《世界地质》2007,26(4):409-412

为提高矿产储量计算的精确性，本文运用了限制性克立格法。给出了限制性克立格法的计算理论，并设计出限制性克立格法在阿舍勒铜矿中的储量计算流程，实现了对阿舍勒铜矿体的限制性克立格储量计算。结果表明，限制性克立格法的储量计算结果（783654．39t）要比普通克立格法的储量计算结果（706541．53t）更接近于实际勘探值（919454t），限制性克立格储量计算方法能够取得较为理想的预测结果。  相似文献   

Why do they burn the 'bush'? Fire, rural livelihoods, and conservation in Zambia     

CHRISTINE ERIKSEN 《The Geographical journal》2007,173(3):242-256

Despite the historical importance of fire as a savanna land management tool, much controversy still surrounds discussions on anthropogenic fire utilization and the sustainability of indigenous land management practices in African savannas. This controversy is arguably a result of a discord between official fire policies and actual indigenous fire practices – a discord based on a gap in existing knowledge of, and a lack of informed literature on, the importance of fire for socio-economic and environmental survival in savanna environments. Addressing a continuing lack of research on the political ecology of fire, this study investigates the historical and present day socio-economic, environmental and political frameworks that affect anthropogenic burning regimes and land management in the Kafinda Game Management Area and Kasanka National Park in Zambia. A series of participatory research activities revealed the continuing importance of fire to rural livelihoods, but that a mismatch in desired burning regimes exists between local stakeholders. The paper argues that local power relations are preventing the local communities from adopting burning regimes that would be more environmentally sustainable and more in line with present day farming systems.  相似文献   

黄河中上游河道生态水短缺价值损失探讨   总被引：1，自引：0，他引：1  

王会肖  覃龙华 《地理研究》2007,26(1):29-36

作为生态系统中最为关键和重要的因素,黄河中上游的水资源十分短缺,而如何定量计算由于水短缺而导致的生态价值损失是一个复杂的问题。本文首先对生态价值进行分类,并对国内常用的评估方法进行介绍。根据黄河中上游的特点将生态需水分为输沙需水、基本生态需水和蒸发需水三个部分,在此基础上,利用市场价值法和影子工程法对短缺水量引起的生态价值损失进行了计算。结果显示2002年黄河中上游生态价值损失中由泥沙淤积引起的部分最大,达到了35.3亿元,其次是水质污染和渔业损失,分别为15.5亿和8.0亿元。由于数据的限制,本文未对水土保持、净化空气、科学文化功能等其他生态价值损失进行计算。最后提出跨流域调水是弥补生态损失的有效方法。  相似文献   

广西农业干旱动态评估模型   总被引：27，自引：0，他引：27  

李艳兰罗莹  黄雪松 《广西气象》2006,27(2):11-14

以自然条件下大气-作物-土壤系统的水量平衡方程为基础，结合广西干旱灾害特点，建立广西农业干旱评估模型。与广西历史农业旱情实况对比分析表明，该模型能够较客观、定量地对农业干旱的发生、发展过程进行逐日动态监测和灾中、灾后评估。  相似文献