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181.
我国经济高速发展的同时,出现了矿产资源大量消耗和环境严重污染的问题。许多学者认为是矿产资源国家所有权惹的祸,极力倡导所有权改制。从理性的角度出发分析,出现这种现象并不是国家所有权惹的祸,而是国家所有权的管理体制不再适应今天市场化的要求,应从管理体制和竞争方面来加强矿产资源的管理。 相似文献
182.
The management of endangered species under climate change is a challenging and often controversial task that incorporates input from a variety of different environmental, economic, social, and political interests. Yet many listing and recovery decisions for endangered species unfold on an ad hoc basis without reference to decision‐aiding approaches that can improve the quality of management choices. Unlike many treatments of this issue, which consider endangered species management a science‐based problem, we suggest that a clear decision‐making process is equally necessary. In the face of new threats due to climate change, managers’ choices about endangered species require closely linked analyses and deliberations that identify key objectives and develop measurable attributes, generate and compare management alternatives, estimate expected consequences and key sources of uncertainty, and clarify trade‐offs across different dimensions of value. Several recent cases of endangered species conservation decisions illustrate our proposed decision‐focused approach, including Gulf of Maine Atlantic salmon (Salmo salar) recovery framework development, Cultus Lake sockeye salmon (Oncorhynchus nerka) management, and Upper Columbia River white sturgeon (Acipenser transmontanus) recovery planning. Estructuración de Decisiones para Manejar Especies Amenazadas y en Peligro en un Clima Cambiante 相似文献
183.
《International Journal of Sustainable Engineering》2013,6(2):106-120
There is a widespread recognition of the need for better information sharing and provision to improve the viability of end-of-life (EOL) product recovery operations. The emergence of automated data capture and sharing technologies such as RFID, sensors and networked databases has enhanced the ability to make product information; available to recoverers, which will help them make better decisions regarding the choice of recovery option for EOL products. However, these technologies come with a cost attached to it, and hence the question ‘what is its value?’ is critical. This paper presents a probabilistic approach to model product recovery decisions and extends the concept of Bayes' factor for quantifying the impact of product information on the effectiveness of these decisions. Further, we provide a quantitative examination of the factors that influence the value of product information, this value depends on three factors: (i) penalties for Type I and Type II errors of judgement regarding product quality; (ii) prevalent uncertainty regarding product quality and (iii) the strength of the information to support/contradict the belief. Furthermore, we show that information is not valuable under all circumstances and derive conditions for achieving a positive value of information. 相似文献
184.
Option value is estimated for the Washakie Wilderness, northwest Wyoming, USA, using the contingent valuation technique. Consumer
surplus, the traditional measure of economic value, is estimated separately and compared with option value. Several populations
are tested, including Washakie visitors, Yellowstone National Park visitors, and residents from four metropolitan test markets:
Salt Lake City, Utah; Portland, Oregon; Nashville, Tennessee; and Orlando, Florida, USA. The average annual preservation option
value (consumer surplus) expressed by on-site wilderness visitors is $46.17 ($80.13), by urban residents is $9.70 ($8.97),
and by rural residents is $8.43 ($7.80). Four selected attributes are determined to be important in motivating option demand
for the Washakie, including existence value, bequest value, the desire for an on-site visit, and interest in securing the
visiting privileges of others. The results suggest that option value is important in wilderness valuation and that off-site
users account for a large part of the economic value of wilderness. 相似文献
185.
本文讨论了区域水资源的评价问题.无论是地表水、地下水,还是土壤水都是来源于大气降水,降水资源才是区域总水资源;同时讨论了区域水资源的平衡原理.降水资源转化了截留水、地表水、土壤水和地下水4项水资源.该文对这2种不同的水体进行了深入讨论,着重论述了土壤水资源的概念及其特征.并对潜水蒸发和水资源的价值问题提出了看法. 相似文献
186.
镍的作物效应及临界值研究 总被引:11,自引:0,他引:11
在三种紫色土(酸性,中性,石灰性)上添加Ni(0,10,30,60,100,200mg/kg土)进行莴笋盆栽试验,结果表明:低浓度的Ni能刺激作物生长,而高浓度的Ni则阻碍作物生长,使叶片黄化。三种土因性质及本身肥力水平的差异,使酸性紫色土上作物Ni最敏感,石灰性紫色土上次之,中性紫色土上最不敏感,且Ni在作物体内分配规律也有所不同,比较了土壤全Ni,有效Ni,植株根Ni作为的临界值的优越性,结果 相似文献
187.
Martha L. Crouch 《Journal of Agricultural and Environmental Ethics》1995,8(2):98-111
Biotechnology increases commercialization of food production, which competes with food for home use. Most people in the world grow their own food, and are more secure without the mediation of the market. To the extent that biotechnology enhances market competitiveness, world food security will decrease. This instability will result in a greater gap between rich and poor, increasing poverty of women and children, less ability and incentive to protect the environment, and greater need for militarization to maintain order. Therefore, biotechnology should be discouraged. An active program to protect and strengthen local food production and to decrease reliance on industrial agriculture should be promoted. 相似文献
188.
She-Kong Chong Stephen M. Moore 《Journal of the American Water Resources Association》1983,19(2):277-282
ABSTRACT: Twenty-two gaging stations were selected for developing a regional flood frequency curve for small (area less than 2 square miles) watersheds in southern Illinois. Five probability functions were compared, and the extreme value type I function was selected to develop the regional flood curve. The curve was generated with the index flood method and also another empirical method that related the function parameters to the watershed area. Estimated peak discharges with various return periods were compared with the results obtained from multiple regression analysis. 相似文献
189.
本文通过对人道主义思想和可持续发展理念的剖析,阐述了可持续发展理念的内涵和实质对人道主义思想精神内核的质疑,指出现代工业文明价值指针的片面所在,提出随着经济发展和社会进步,人类应该重新审视自然与人的关系,践行“协调”与“和谐”的人地共生论;应该重新审视自然的宽泛价值,认识“非资源”的非经济价值,从而实现文明取向和价值评判上的转型与重铸,以使可持续发展真正得以良性持续。 相似文献
190.