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71.
Randy L. Ulery Peter C. Van Metre Allison S. Crossfield 《Journal of the American Water Resources Association》1993,29(4):685-711
ABSTRACT: In 1991 the Trinity River Basin National Water-Quality Assessment (NAWQA) was among the first 20 study units to begin investigations under full-scale program implementation. The study-unit investigations will include assessments of surface-water and ground-water quality. Initial efforts have focused on identifying water-quality issues in the basin and on the environmental factors underlying those issues. The environmental setting consists of both physical and cultural factors. Physical characteristics described include climate, geology soils, vegetation, physiography, and hydrology. Cultural characteristics discussed include population distribution, land use and land cover, agricultural practices, water use, and reservoir operations. Major water-quality categories are identified and some of the implications of the environmental factors for water quality are presented. 相似文献
72.
73.
Bishnu Tulsie 《Natural resources forum》2006,30(2):102-110
In response to domestic development challenges and calls from the international community for countries to develop and begin the implementation of national sustainable development strategies by 2005, the Government of Saint Lucia initiated a project named Integrated Planning for Sustainable National Development in 2002. Under this initiative, it was intended to articulate a vision for the country's development and use this as the basis for identifying a set of development imperatives through a process that will superimpose identified national development goals and targets on the international sustainable development agenda to arrive at a national strategy and plan for sustainable development. The plan also called for institutional and structural adjustments to move the country away from current sectoral‐based development planning to an environment of dialogue, cooperation and collaboration among development partners in the articulation of development policies, plans and projects. The initiative did not evolve as planned mainly due to inadequate political and financial support and the inability of key institutions to see the bigger picture this initiative tried to paint for the nation. 相似文献
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75.
内蒙古乌兰浩特索伦镇地区中生代侵入岩特征研究 总被引:1,自引:0,他引:1
内蒙古乌兰浩特索伦镇地区位于大兴安岭中南段。该区中生代侵入岩广泛发育。开展侵入岩的年代学、地球化学特征研究能为深入探讨区域构造背景提供依据。3个样品K-Ar全岩法测年结果(93.39Ma~108.48Ma)证明侵入岩形成于早白垩世,略晚于其南侧同一构造带上的杜尔基地区侵入岩年龄(100.15Ma~120.29Ma),符合太行山——大兴安岭早白垩世侵入岩时代自南向北由老变新的演化趋势。岩石地球化学分析结果显示岩石属于碱性系列,具有高硅、高钾、富碱、过铝、贫钙、镁、铁等特征。稀土元素总量为(77.96~241.29)μg/g,平均值为158.92μg/g,与杜尔基地区早白垩世侵入岩的稀土总量平均值(146.85μg/g)及华北克拉通内碱性系列岩石的稀土总量平均值(163.32μg/g)都非常接近。稀土元素球粒陨石标准化曲线整体右倾,因Eu负异常而呈"V"型形态,与太行山-大兴安岭地区早白垩世典型岩体的稀土配分型式极为相似。侵入岩的成因类型为A-型,形成于伸展构造环境。 相似文献
76.
GEORGINA M. MACE NIGEL J. COLLAR KEVIN J. GASTON CRAIG HILTON‐TAYLOR H. RESIT AKÇAKAYA NIGEL LEADER‐WILLIAMS E.J. MILNER‐GULLAND SIMON N. STUART 《Conservation biology》2008,22(6):1424-1442
Abstract: The International Union for Conservation of Nature (IUCN) Red List of Threatened Species was increasingly used during the 1980s to assess the conservation status of species for policy and planning purposes. This use stimulated the development of a new set of quantitative criteria for listing species in the categories of threat: critically endangered, endangered, and vulnerable. These criteria, which were intended to be applicable to all species except microorganisms, were part of a broader system for classifying threatened species and were fully implemented by IUCN in 2000. The system and the criteria have been widely used by conservation practitioners and scientists and now underpin one indicator being used to assess the Convention on Biological Diversity 2010 biodiversity target. We describe the process and the technical background to the IUCN Red List system. The criteria refer to fundamental biological processes underlying population decline and extinction. But given major differences between species, the threatening processes affecting them, and the paucity of knowledge relating to most species, the IUCN system had to be both broad and flexible to be applicable to the majority of described species. The system was designed to measure the symptoms of extinction risk, and uses 5 independent criteria relating to aspects of population loss and decline of range size. A species is assigned to a threat category if it meets the quantitative threshold for at least one criterion. The criteria and the accompanying rules and guidelines used by IUCN are intended to increase the consistency, transparency, and validity of its categorization system, but it necessitates some compromises that affect the applicability of the system and the species lists that result. In particular, choices were made over the assessment of uncertainty, poorly known species, depleted species, population decline, restricted ranges, and rarity; all of these affect the way red lists should be viewed and used. Processes related to priority setting and the development of national red lists need to take account of some assumptions in the formulation of the criteria. 相似文献
77.
在土壤环境质量监测点位布设工作中,利用高分辨率遥感影像等数据和资料,可以增强点位布设结果的规范性和合理性。基于环境保护部和中国环境监测总站下发的土壤环境质量监测点位布设技术方案,分别介绍了基础点位、风险点位和背景点位的总体布设方式和布设要求,以及高分辨率遥感影像在各类点位理论布设中的具体应用方法。 相似文献
78.
结合我国污染场地的普遍特征以及场地初步调查的基本目标,从布点前期准备、布点原则、布点程序和布点方法等方面详细探讨了污染场地土壤初步调查的点位布设方法;并从采样准备、采集方法、采集程序以及现场记录等环节探讨了现场样品采集的注意事项和要求,以期为污染场地环境调查的土壤监测和采样提供借鉴。 相似文献
79.
One Hundred Questions of Importance to the Conservation of Global Biological Diversity 总被引:3,自引:0,他引:3
W. J. SUTHERLAND W. M. ADAMS R. B. ARONSON R. AVELING T. M. BLACKBURN S. BROAD G. CEBALLOS I. M. CÔTÉ R. M. COWLING G. A. B. DA FONSECA E. DINERSTEIN P. J. FERRARO E. FLEISHMAN C. GASCON M. HUNTER Jr. J. HUTTON P. KAREIVA A. KURIA D. W. MACDONALD K. MACKINNON F. J. MADGWICK M. B. MASCIA J. MCNEELY E. J. MILNER‐GULLAND S. MOON C. G. MORLEY S. NELSON D. OSBORN M. PAI E. C. M. PARSONS L. S. PECK H. POSSINGHAM S. V. PRIOR A. S. PULLIN M. R. W. RANDS J. RANGANATHAN K. H. REDFORD J. P. RODRIGUEZ F. SEYMOUR J. SOBEL N. S. SODHI A. STOTT K. VANCE‐BORLAND A. R. WATKINSON 《Conservation biology》2009,23(3):557-567
Abstract: We identified 100 scientific questions that, if answered, would have the greatest impact on conservation practice and policy. Representatives from 21 international organizations, regional sections and working groups of the Society for Conservation Biology, and 12 academics, from all continents except Antarctica, compiled 2291 questions of relevance to conservation of biological diversity worldwide. The questions were gathered from 761 individuals through workshops, email requests, and discussions. Voting by email to short-list questions, followed by a 2-day workshop, was used to derive the final list of 100 questions. Most of the final questions were derived through a process of modification and combination as the workshop progressed. The questions are divided into 12 sections: ecosystem functions and services, climate change, technological change, protected areas, ecosystem management and restoration, terrestrial ecosystems, marine ecosystems, freshwater ecosystems, species management, organizational systems and processes, societal context and change, and impacts of conservation interventions. We anticipate that these questions will help identify new directions for researchers and assist funders in directing funds. 相似文献
80.
基于湖南现存的一些古村落,从物质安全防御角度出发,对古村落在基地选址、整体布局、空间形态等方面所采用的安全防御进行研究。通过分析湖南当地居民的主要物质防御手段即利用山水作为村落的自然屏障、团结所有村民进行集群防御与在村落内部层层设防等方法,指出湖南古村落物质防御的有效性和科学性对当今社会安居工程建设具有借鉴意义。 相似文献