With 21 % of gross domestic product (GDP) in agricultural sector and having consistently experienced natural disasters (e.g., drought, flood), Armenia is very vulnerable to climate and its change. Given the fact that 63 % of the entire land is planted with grains, this study primarily focuses on the market for wheat flour and bread. Economic welfare loss due to drought episodes is calculated using the economic data integrated with climate measures. Economic data are utilized for the period 1995–2011 (obtained from Statistical Office of Armenia) and specifically include the quantity produced and consumed of wheat flour and bread combined with mean prices, population income, GDP in the agricultural sector, GDP in the planting sector, and governmental expenditure on subsidies. Climate data include temperature and precipitation during the period 1966–2011 (obtained from National Hydrometeorological Service of Armenia). The analysis includes three main components. The first utilizes a market framework that analyzes the impact of climate on equilibrium prices and quantities as well as trade and tax effects. The second employs a logarithmic utility function to estimate the effective insurance policy for the agricultural sector using risk management strategies. Lastly, a macroeconomic model has been developed to assess the efficient sum of governmental expenditure on subsidies and irrigation during the drought episodes and during the mean climatic conditions. All three parts of the study are developed for the first time. 相似文献
Abstract Charge distributions in 1, 1'‐ethylene‐2, 2'‐bipyridylium (diquat), 1,1'‐dimethyl‐4,4'‐bipyridylium (paraquat) and 1‐methylpyridinium organocations were calculated by a Complete Neglect of Differential Overlap semi‐empirical quantum mechanical procedure. The data show that the positive charges in the organocations are distributed around the molecules and are greatest in the positions ortho and para to the heterocyclic nitrogen atoms. Earlier interpretations of the mechanisms of adsorption of paraquat and diquat by soils and clays assumed that the charges were located in the heterocyclic nitrogen atoms. Here some consideration is given to the influence of the charge delocalizations on the processes of adsorption by montmorillonite and vermiculite clay preparations. 相似文献
Poor countries are disproportionately affected by the cost of disasters. Yet there is evidence of the benefits of seeking
to mitigate the impact of a disaster, compared with the costs incurred in ‘making good’ after a major event has occurred.
This article reviews a programme of landslide risk reduction in unplanned communities in the Eastern Caribbean. The construction
of appropriate surface water management measures, based on the application of scientific and engineering principles, has been
demonstrated to reduce the hazard from rainfall-triggered landslides. Adopting a community-based approach additionally delivers
social and environmental benefits relating to employment generation, improvements in the environmental conditions within the
community, and improvements slope management practices. The sustained implementation of the community-based projects has provided
the necessary evidence-base for these practices to influence Government policy and practice, and gain recognition from regional
development agencies. The strategic and incremental uptake of the community-based methodology is demonstrated to be an effective
means for delivering physical landslide risk reduction measures in the most ‘at risk’ areas of unplanned housing. 相似文献
There is a requirement to verify the performance of sorbent-based passive or active samplers and to extend their use, where possible, to monitor volatile organic compounds (VOCs) that are known to be photochemical ozone pre-cursors or are relevant to the activities of the petrochemical industry. We report measurements of the 14-day diffusive uptake rates for the VOCs: i-butane (2-methyl propane), n-butane, i-pentane (2-methyl butane), n-pentane, n-hexane, benzene, toluene, and m-xylene (at environmental level concentrations) for industry standard axial samplers (Perkin–Elmer-type samplers) containing the sorbents Carbopack-X, -Z, -B or Tenax-TA. We also present data on back-diffusion, blank levels, and storage for the above sorbents, and describe the simultaneous use of the sorbent Carbopack-X for pumped sampling of certain VOCs. The results were obtained by dosing samplers in a controlled atmosphere test facility (CATFAC) operating under well-defined conditions of concentration, nominal temperature of 20 °C, wind speed of 0.5 m s?1, and relative humidities of 0% and 80%. Field measurements were also obtained to provide supplementary data to support the laboratory study. Results are compared to existing published data, where these are available. 相似文献
ABSTRACT: A time series of annual flow of the Sacramento River, California, is reconstructed to A.D. 869 from tree rings for a long‐term perspective on hydrologic drought. Reconstructions derived by principal components regression of flow on time‐varying subsets of tree‐ring chronologies account for 64 to 81 percent of the flow variance in the 1906 to 1977 calibration period. A Monte Carlo analysis of reconstructed n‐year running means indicates that the gaged record contains examples of drought extremes for averaging periods of perhaps = 6 to 10 years, but not for longer and shorter averaging periods. For example, the estimated probability approaches 1.0 that the flow in A.D. 1580 was lower than the lowest single‐year gaged flow. The tree‐ring record also suggests that persistently high or low flows over 50‐year periods characterize some parts of the long‐term flow history. The results should contribute to sensible water resources planning for the Sacramento Basin and to the methodology of incorporating tree‐ring data in the assessment of the probability of hydrologic drought. 相似文献
ABSTRACT: Current conventions for reporting analytical results from environmental samples brings the objectives of laboratory scientists into conflict with those of environmental scientists. The objective of chemical analyses is to provide estimates of the true composition of samples. Reported results must reflect the analytical uncertainty. Current conventions require left-censoring of those results below the Limit of Detection. The objective of statistical interpretation of environmental data is to provide estimates of the characteristics of ecosystems. Such statistical analyses are often confounded by left-censoring of analytical results. We review the different points of view and propose a compromise which recognizes these conflicting perspectives. 相似文献
The practice of EIA preparation in a number of states and countries is reviewed in the light of the need to avoid bias, integrate the EIA with project design, and make the proponent pay. It is concluded that the best arrangement may be to make the proponent responsible for EIA preparation and to advise a number of constraints designed to improve the quality of the studies and reduce bias. First, the proponent should be required to select a consultant from a register of those known to be honest, unbiased, technically competent, and capable of working with a design team. Second, two steering committees should be established to identify key issues, specify data collection and modeling programs and methods, and ensure that the study stays on course. 相似文献
The paper comments on the development of an international movement towards both sustainability and subsidiarity in the management of large river basins, and also stresses the significance of river basins for their sense of place and symbolism as environmental territory. Two contrasting efforts are compared, in the developed world (European Community) through the Freshwater Europe Campaign, and in the developing world through the lead‐in to the Earth Summit. Finally, suggestions are made that the best manifesto for the problem of water and development is an ecosystems approach to the river basin, modified by a greater use of approaches from social science and objectives of social justice. 相似文献
Sustainable development and solutions to existing environmental problems depend heavily on information and its translation into usable knowledge. Increasingly, affected communities are being drawn into environmental decision‐making, both in the development of strategy (plans) and in the delivery of plans through management and operations. Variants of the ‘natural capital’ theme are popular amongst those who see an effective dialogue between the sciences of ecology and economics as the most promising interdisciplinary context for environmental decision making by empowered communities. A decision‐making framework is vital in practical, community‐based schemes (wider than ‘stakeholder platforms’) which have become popular for promoting ‘best practice’ in managing river basin units. The EU Water Framework Directive renders use of interdisciplinary techniques within a participatory framework a statutory requirement. A final practical need for communities and professionals involved with such schemes is the creation of a system of adaptive (rather than reactive) management, supported by ongoing research and monitoring to detect, and adjust to, ever‐changing physical and social contexts for both strategies and operations.
This paper describes the authors' experience in applying the ‘Environmental Capital’ (also known as ‘Quality of Life Capital’ (QoLC)) approach to information management in two headwater catchments in northern England: the Wharfe and the Coquet. In the case of the Upper Wharfedale Best Practice Project (UWBPP) the components of basic environmental survey, consultation, strategy formulation and the use of the strategy are illustrated to guide immediate and longer‐term actions. In contrast, the Coquet application of the technique, whilst socially more pervasive, was less successful for a number of reasons: geographical, institutional, project and participatory.
As a proposed development of the methodology based on the authors' experiences, extending public participation through monitoring activity, together with formal application of environmental economics to the perceived elements of ‘natural’ and ‘human’ capital in the two catchments would appear desirable. Conclusions are also drawn regarding the demands of the EU Water Framework Directive for ecological, economic and participatory approaches to river basin planning and management. 相似文献
The effects of paramagnetic species on solid state 13C nuclear magnetic resonance (NMR) spectra were quantified in a series of doping experiments. The degree of signal loss caused by paramagnetic metals was shown to depend not only on the quantity, but also on the nature of the paramagnetic species, as well as the intimacy of contact with the organic substrate and the type of NMR experiment. Two mechanisms of signal loss were distinguished--signal loss via loss of magnetic field homogeneity, which affects all 13C nuclei in a sample, and signal loss via interaction between electronic and nuclear spins, the effects of which were localized to the close environment of the paramagnetic species. Loss of field homogeneity is important for manganese species, but not for copper species, and is equally important for both cross polarization and Bloch decay experiments. The interaction between electronic and nuclear spins is highly dependent on the spin-lattice relaxation rate constant of the free electron (T1e), as cations with very short T1e values (e.g., Pr3+) cause less signal loss than cations with longer T1e values (e.g., Cu2+, Mn2+). Cross polarization spectra are shown to be more susceptible than Bloch decay spectra to this mechanism of signal loss. Signal loss and increased relaxation rates brought about by paramagnetic species can be used to provide information on soil organic matter (SOM) heterogeneity in the submicron range. This is demonstrated for SOM doped with paramagnetic cations where selective signal loss and increased relaxation rates are used to determine the nature of cation exchange sites. 相似文献