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Mark E. Jensen Roland L. Redmond Jeff P. Dibenedetto Patrick S. Bourgeron Iris A. Goodman 《Environmental monitoring and assessment》2000,64(1):197-212
The Little Missouri National Grasslands (LMNG) of western North Dakota support the largest permitted cattle grazing use within all lands administered by the USDA, Forest Service, as well as critical habitat for many wildlife species. This fact, coupled with the need to revise current planning direction for range allotments of the LMNG, necessitated that a broad-level characterization of ecosystem integrity and resource conditions be conducted across all lands within the study area (approximately 800,000 hectares) in a rapid and cost-effective manner. The approach taken in this study was based on ecological classifications, which effectively utilized existing field plot data collected for a variety of previous inventory objectives, and their continuous spatial projection across the LMNG by maps of both existing and potential vegetation. These two map themes represent current and reference conditions (existing vs. potential vegetation); their intersection allowed us to assign various ecological status ratings (i.e., ecosystem integrity and resource condition) based on the degree of departure between current and reference conditions. In this paper, we present a brief review of methodologies used in the development of ecological classifications, and also illustrate their application to assessments of rangeland health through selected maps of ecological status ratings for the LMNG. 相似文献
884.
Li Ning 《中国人口.资源与环境(英文版)》2012,(2):51-59
China's circular economy is still at the initial stage, whose development has many difficulties and problems requiring immediate resolution theoretically and practically. Due to the differences of regions on the scale of land, endowment of resources, economic basis and cultural background, the developmental levels and capabilities of circular economy are inevitably different. Based on establishing the indicator system for assessing the developmental level of regional circular economy, spatial variation of China's circular economy is measured by the quantitative measurement using principal component analysis, and the existing problems are also analyzed and discussed. On one hand, the differences of the development capability of the circular economy of different provinces (cities) are profound in China; ①Difference between the first category (strong) and the second category (relatively strong) is 1.1264 points. Difference between the second category and the third category (relatively weak) is 0.3867 points. Difference between the third category and the fourth category (weak) is 1.0238 points. Difference between the first category and the fourth category reaches up to 2.0869 points. Average difference between the area where the developmental level of circular economy is relatively strong and the area where the developmental level of circular economy is relatively weak is 1.3617 points. ②The differences of the distribution of the areas, with different development capability of circular economy, which are located in the three economic regions of China, are also profound. The regions with a relatively strong development capability of circular economy are mainly located in the eastern economic area, which account for 22.58% of the whole regions, while only account for 12.90% in the middle and western economic areas. On the contrary, the regions with a relatively weak development capability of circular economy account for 48.39% in the middle and western area, while account for 16.13% in the eastern area. On the other hand, among regions with different development capability of circular economy, the regions with a relatively weak development capability of circular economy are in a dominant position, which accountfor 64.52% of all the provinces (cities), which indicates that the development of the China's circular economy still has a long way to go. Though certain achievements have been made in the development of China's circular economy, in general, there are still some obstacles to be tacked in the development of China's circular economy which require the economic, legal and administrative methods. 相似文献
885.
Patrick Mwendwa 《中国人口.资源与环境(英文版)》2012,10(1):73-79
The aim of this paper is to illustrate the benefits,and challenges towards providing multifunctional urban green spaces.The results are based on critical analysis of study findings from different cities in Europe,America and to a lesser extent in Asia.Inner-city green spaces are especially important for improving air quality through uptake of pollutant gases and particulates which are responsible for respiratory infections.Due to their amenity and aesthetics,green spaces increase property value.To ensure multifunctional role of urban a green space is achieved,in particular the social and psychological role,certain standards of quantity,quality and distribution within the urban area should be adequately established.Green spaces need to be uniformly distributed throughout the city area,although each does not need to be extremely large but should be large enough to accommodate the city population. 相似文献
886.
露天采矿产生的水土流失、次生地质灾害等生态负效应强度受矿山所处的地理环境控制。金沙江流域露天矿区众多,地形复杂,采矿后产生的生态负效应易受脆弱的地理环境放大,因此对流域内露天矿区进行开采条件的生态适宜性评价,对保护环境具有重要意义。采用RS、GIS等空间技术,在ArcGIS环境下建立了金沙江流域(云南段)露天矿区的空间数据库,以其中的10个典型露天矿区为研究对象,在对比分析了这些露天矿区的地理环境后,选取了地貌、海拔、坡度、植被覆盖度、植被类型及流域位置等作为评价指标,对典型露天矿区进行开采条件的生态适宜性评价。评价方法涉及专家打分、灰色关联法等。研究得出流域内10个典型露天矿的空间分布特征及开采条件的生态适宜性。研究成果为流域内露天矿区资源的合理开发利用及生态保护提供一定的科学依据 相似文献
887.
随着城市建设的不断推进,中央商务区(CBD)的可持续发展受到越来越多关注。随着全球气候变化的日益加剧,低碳CBD作为一种新型的CBD发展模式被提出。基于国内外已有的CBD建设研究,以可持续发展理念为指引,在解析CBD发展历程的基础上,探究了中国CBD低碳建设的路径和策略。CBD的碳排放特征分析表明,"低碳CBD"的发展路径必须将低碳理念贯彻到规划期、建设期及运营期等各个阶段,坚持全生命周期的低碳管理。最后,从量化低碳目标、创新低碳政策和持续改进地管理低碳建设3个方面提出了低碳CBD的发展策略。 相似文献
888.
利用废弃绿茶叶粉末(简称茶叶末)作为吸附剂,考察了pH、温度、时间等对水溶液中Co2+的影响。结果表明:(1)茶叶末对Co2+的吸附量随着pH的上升而上升,其中pH=5.50为最佳。茶叶末对Co2+的吸附量均随时间延长呈现上升趋势,吸附速度先快后慢,吸附最佳时间为90min。(2)不同温度下,茶叶末对Co2+的吸附较好地符合Langmuir模型。该吸附过程是化学离子交换过程,主要发生在重金属离子与羟基、氨基的氢原子之间。(3)茶叶末对Co2+的吸附是自发、放热过程,降温有利于吸附,反应时吸附界面上的混乱度增加。(4)盐酸是很好的解吸介质,解吸率为92.65%。通过灼烧(或燃烧)可以回收水溶液中绝大部分的Co2+,不仅减小了对环境的污染,而且节约了资源。 相似文献
889.
Golubiewski N 《Ambio》2012,41(7):751-764
The energy and material flows of a city are often described as urban metabolism (UM), which is put forward as a way to link a city's ecology and economy. UM draws parallels to the biology of individual organisms, yet the analogy is misapplied. In striving to be interdisciplinary, UM makes this organismic comparison rather than identifying the city as an ecosystem, thereby ignoring developments in ecological theory. Using inappropriate rhetoric misdirects researchers, which influences scientific investigation-from problem statements to interpretations. UM is valuable in quantifying the city's use of natural resources but does not achieve a comprehensive, integrated analysis of the urban ecosystem. To realize an interdisciplinary, perhaps transdisciplinary, understanding of urban ecology, researchers need to emphasize the essential tenets of material flows analysis, view the city as an ecosystem, and use language that properly reflects current knowledge, theory, and conceptual frameworks in the foundational disciplines. 相似文献
890.
"十一五"是新疆经济飞速发展的五年,同时也是重大生态保护工程十五实施期。本文采用国家环境保护部制定的《生态环境状况评价技术规范》(HJ/T192-2006)分别对新疆"十五"末与"十一五"末生态环境质量进行综合评价分析。结果显示:塔里木河流域生态环境质量总体处于较差水平,各县(市)生态环境质量以较差和差为主,二者面积总和在全区总面积60%以上;与"十五"末相比,全区生态环境质量保持稳定,无明显变化。呈现总体趋于稳定,局部区域有所改善的特征。 相似文献