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921.
George M. Leigh William S. Hearn Kenneth H. Pollock 《Environmental and Ecological Statistics》2006,13(1):89-108
Instantaneous natural mortality rates and a nonparametric hunting mortality function are estimated from a multiple-year tagging
experiment with arbitrary, time-dependent fishing or hunting mortality. Our theory allows animals to be tagged over a range
of times in each year, and to take time to mix into the population. Animals are recovered by hunting or fishing, and death
events from natural causes occur but are not observed. We combine a long-standing approach based on yearly totals, described
by Brownie et al. (1985, Statistical Inference from Band Recovery Data: A Handbook, Second edition, United States Fish and Wildlife Service, Washington, Resource Publication, 156), with an exact-time-of-recovery
approach originated by Hearn, Sandland and Hampton (1987, Journal du Conseil International pour l’Exploration de la Mer, 43, 107–117), who modeled times at liberty without regard to time of tagging. Our model allows for exact times of release
and recovery, incomplete reporting of recoveries, and potential tag shedding. We apply our methods to data on the heavily
exploited southern bluefin tuna (Thunnus maccoyii). 相似文献
922.
资源型城市生态承载力对土地利用变化的响应 总被引:5,自引:0,他引:5
探讨了鞍山、抚顺和本溪3个资源型城市1996-2000年生态承载力的变化趋势、土地利用程度综合指数变化以及生态承载力对土地利用变化的响应.结果表明:鞍山、抚顺和本溪3市1996-2000年生态承载力隶属度呈上升趋势,但均属一般水平,2000年分别为0.60、0.47、0.49;鞍山、抚顺和本溪3市土地利用程度变化综合指数分别为0.82、4.04、1.10,鞍山、本溪土地利用强度低,抚顺土地利用强度高;鞍山、抚顺、本溪3市生态承载力与土地利用程度综合指数的变化呈正相关趋势,能够基本达到相互促进的发展模式. 相似文献
923.
用于含油污水处理的气浮旋流耦合技术研究 总被引:3,自引:0,他引:3
建立了气浮旋流耦合装置。测试了气浮旋流耦合装置的分离效果,实验表明,在加气量质量比为0.003-0.020,含油污水浓度为50—300mg/L条件下,气浮旋流耦合装置可比单纯的旋流分离装置的分离效率提高10%,50%。 相似文献
924.
925.
介绍了砀山县近期处理规模为25000m^3/d、采用一体化氧化沟工艺的污水处理厂的设计情况,并针对雨污合流制采取了一系列的解决措施。 相似文献
926.
In this paper, we present a general method, based on a convex optimisation technique, that facilitates the coupling of climate and economic models in a cost-benefit framework. As a demonstration of the method, we couple an economic growth model à la Ramsey adapted from DICE-99 with an efficient intermediate complexity climate model, C-GOLDSTEIN, which has highly simplified physics, but fully 3-D ocean dynamics. As in DICE-99, we assume that an economic cost is associated with global temperature change: this change is obtained from the climate model, which is driven by the GHG concentrations computed from the economic growth path. The work extends a previous paper in which these models were coupled in cost-effectiveness mode. Here we consider the more intricate cost-benefit coupling in which the climate impact is not fixed a priori. We implement the coupled model using an oracle-based optimisation technique. Each model is contained in an oracle, which supplies model output and information on its sensitivity to a master program. The algorithm Proximal-ACCPM guarantees the convergence of the procedure under sufficient convexity assumptions. Our results demonstrate the possibility of a consistent, cost-benefit, climate-damage optimisation analysis with a 3-D climate model. 相似文献
927.
Section 305(b) of the United States’ Clean Water Act (CWA) requires states to assess the overall quality of waters in the
states, while Section 303(d) requires states to develop a list of the specific waters in their state not attaining water quality
standards (a.k.at impaired waters). An integrated, efficient and cost-effective process is needed to acquire and assess the data needed to
meet both these mandates. A subset of presentations at the 2002 Environmental Monitoring and Assessment Program (EMAP) Symposium
provided information on how probability data, tools and methods could be used by states and other entities to aid in development
of their overall assessment of condition and list of impaired waters. Discussion identified some of the technical and institutional
problems that hinder the use of EMAP methods and data in the analysis to identify impaired waters as well as development needs
to overcome these problems. 相似文献
928.
Air pollution leads to serious negative impacts on health. Thephysical evidence is compelling. An attempt has been made inthis paper to establish dose-response relationship of AmbientAir Quality Index and human health, based on time spent by anindividual in different microenvironments during one day.Economic valuation of morbidity and mortality has been attemptedthrough lost salary approach. The results show that theavoidance cost is 29% of the total health damage cost. 相似文献
929.
Policy concerns related to the environment have grown in the past decadesfrom relatively local and well-defined problems to increasingly complex andglobal issues. With this has grown the need to develop the capacity tointegrate, reconcile, organize, and communicate knowledge across scientificdisciplines, as well as to make this knowledge available and useful for policy-makers. One response to this has been the growing field ofIntegrated Assessment (IA). Our goal in this paper is to reflect on the purpose and valueof IA in principle. We propose a conceptual framework within whichindividual IA studies, and the practice of IA as a whole, can be placed andevaluated. The framework addresses both the integrative nature of IAs andtheir policy usefulness, including a self-awareness of their role and capabilities. We illustrate several stages in the evolution of integrated assessments: fromlinear to more complex chains of analysis, from non-adaptive to perfectly-adaptive to realistically-adaptive agents, from simplistic to sophisticated to pluralistic consideration of alternative underlying development paths, from strictly quantitative to quantitative and qualitative analyses, from science-driven to policy-driven, and from analyses that dictate to users to those that involvethose users in the actual assessment process. By so doing, we argue for botha richer form and process of IA. Ultimately, we feel that it may also benecessary to reconsider the framing of the questions that IAs have been askedto address, perhaps leading to the consideration of the use of other forms of mandated science. 相似文献
930.
Edward A. Parson 《Environmental Modeling and Assessment》1997,2(4):267-279
Practice and research in assessment of global environmental change are dominated by two conventional assessment methods, formal models and expert panels. Models construct a representation of biophysical and socioeconomic components of a policy issue, to project future trends or consequences of interventions. Panels articulate consensus views of policyrelevant knowledge through deliberations among selected experts. These methods make valuable contributions, but are weak in addressing certain kinds of knowledge needs that are typical of globalchange issues. To address these needs, a set of novel assessment methods is proposed that combine elements of representation and deliberation. These methods, of which policy exercises, simulationgaming, and scenario exercises are examples, involve human participants in structured relevant decision and task settings. Relative to models and panels, these methods can more readily incorporate diverse perspectives, can integrate across broader collections of knowledge domains, and can both encourage creative insights and innovations, and provide tests of their relevance and practicality. Risks of bias, and of overconfident generalization from unique experiences, are effectively mitigated by critical debriefings, and appear no more severe than corresponding risks in conventional assessment methods, or in policymakers generalizations from historical experience. While serious development and implementation challenges remain, early experience suggests that these methods can offer useful ideas and insights for policymaking that are not available through other means. 相似文献