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Median hardness and sodium levels in groundwater were calculatedfor 244 Texas counties from measurements at 7728 water wells.The data were mapped and analyzed with a geographic informationsystem (GIS). County median hardness levels varied widely, from4–2304 mg L-1. More than 60% of the counties had hardnessmedians above 180 mg L-1. County medium sodium concentrationsranged from 6–1170 mg L-1, with more than 90% of those valuesexceeding 20 mg L-1. There was a significant positive correlationbetween hardness and sodium concentrations in six of Texas' ninemajor aquifers. A significant negative correlation betweenhardness and sodium was observed in two aquifers. Severalfactors control hardness and sodium variations in Texas aquifers including rock/sediment composition, groundwaterchemical evolution, and seepage from nearby formations. Probablehuman controls include agricultural return flow andpumping-induced saltwater intrusion.  相似文献   

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The response of natural systems to atmospheric change may depend critically on species diversity and on the genetic diversity (variability) found within their respective populations. Yet, most surveys of aquatic invertebrates account for neither. This may be of particular concern for benthic populations in running waters because of the considerable variability and the fragmentary nature of these habitats (e.g. isolated watersheds). In such habitats, species with limited genetic variability and/or limited dispersal capabilities (genetically differentiated populations) may be unable to track rapid environmental change, and may be more susceptible to climatic perturbations. We present a conceptual framework to illustrate some of the potential problems of ignoring population genetics when considering the impacts of global atmospheric change. We then review a simple method to assess population genetic structure and we evaluate available data on the genetic structure of North American stream invertebrates. These data indicate that benthic taxa often consist of genetically differentiated local populations, or even previously unknown species. Accordingly, our limited knowledge of population structure among benthic invertebrates may result in the unwitting loss of genetic and/or species diversity. Enhanced taxonomic research incorporating molecular techniques is clearly warranted. Conservation strategies based on the preservation and remediation of a diversity of aquatic habitats are likely to be our best means of ensuring species and genetic diversity of invertebrate taxa.  相似文献   

4.
It is argued that standard environmental economic and 'ecological economics', have the same fundamentals of valuation in terms of money, based on a demand curve derived from utilitymaximization. But this approach leads to three different measuresof value. An invariant measure of value exists only if the consumer has 'homothetic preferences'. In order to obtain a numerical estimate of value, specific functional forms are necessary, but typically these estimates do not converge. This is due to the fact that the underlying economic model is not structurally stable.According to neoclassical economics, any environmental remediation can be justified only in terms of increases in consumer satisfaction, balancing marginal gains against marginal costs. It is not surprising that the optimal policy obtained fromthis approach suggests only small reductions in greenhouse gases.We show that a unidimensional metric of consumer's utility measured in dollar terms can only trivialize the problem of global climate change.  相似文献   

5.
This paper introduces the use of nutrition profiles as a first step in the development of a concept that is suitable for evaluating forest nutrition on the basis of large-scale foliar surveys. Nutrition profiles of a tree or stand were defined as the nutrient status, which accounts for all element concentrations, contents and interactions between two or more elements. Therefore a nutrition profile overcomes the shortcomings associated with the commonly used concepts for evaluating forest nutrition. Nutrition profiles can be calculated by means of a neural network, i.e. a self-organizing map, and an agglomerative clustering algorithm with pruning. As an example, nutrition profiles were calculated to describe the temporal variation in the mineral composition of Scots pine and Norway spruce needles in Finland between 1987 and 2000. The temporal trends in the frequency distribution of the nutrition profiles of Scots pine indicated that, between 1987 and 2000, the N, S, P, K, Ca, Mg and Al decreased, whereas the needle mass (NM) increased or remained unchanged. As there were no temporal trends in the frequency distribution of the nutrition profiles of Norway spruce, the mineral composition of the needles of Norway spruce needles subsequently did not change. Interpretation of the (lack of) temporal trends was outside the scope of this example. However, nutrition profiles prove to be a new and better concept for the evaluation of the mineral composition of large-scale surveys only when a biological interpretation of the nutrition profiles can be provided.  相似文献   

6.
Technological innovation has generated much interest among scholars, practitioners, and policymakers as a critical instrument for achieving sustainable development. Although the relationship between technological innovation and sustainable development has been extensively discussed in the academic and policy circles, little studies have empirically examined the simultaneous impact of technological innovation on the three pillars of sustainable development. To fill this gap, the present study examines the ability of technological innovation to simultaneously promote economic progress and advance social and environmental conditions in the case of 75 low-, middle-, and high-income countries by demonstrating how this impact differs across the stages of economic development. From both long-run estimates and causality analysis, our findings reveal that technological innovation contributes simultaneously to the three pillars of sustainable development only in the case of rich countries; however, it only affects the economic and environmental dimensions in the middle-income countries, and no impact is found in the case of low-income countries. Future research directions, policy and managerial implications are also discussed.  相似文献   

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Economic analyses of the greenhouse effect are typically carried out within the framework of computable general equilibrium models which represent the climate system by simple two box proxies based upon the pioneering work of Nordhaus. Since errors in predicting the carbon budget can imply high costs, there is some need to include more sophisticated climate models into the economics of global climate change. This paper presents a non-linear pulse representation of the process-based and data-validated Bern carbon model. Compared to the Nordhaus approach this leads to different results with respect to optimal climate policy and atmospheric carbon dioxide concentration. In particular, our results suggest that economic studies which use a Nordhaus representation of the climate system are biased towards high carbon emission and low abatement levels.  相似文献   

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Increasing fragmentation of grassland habitats by human activities is a major threat to biodiversity and landscape quality. Monitoring their degree of fragmentation has been identified as an urgent need. This study quantifies for the first time the current degree of grassland fragmentation in the Canadian Prairies using four fragmentation geometries (FGs) of increasing specificity (i.e. more restrictive grassland classification) and five types of reporting units (7 ecoregions, 50 census divisions, 1,166 municipalities, 17 sub-basins, and 108 watersheds). We evaluated the suitability of 11 datasets based on 8 suitability criteria and applied the effective mesh size (m eff) method to quantify fragmentation. We recommend the combination of the Crop Inventory Mapping of the Prairies and the CanVec datasets as the most suitable for monitoring grassland fragmentation. The grassland area remaining amounts to 87,570.45 km2 in FG4 (strict grassland definition) and 183,242.042 km2 in FG1 (broad grassland definition), out of 461,503.97 km2 (entire Prairie Ecozone area). The very low values of m eff of 14.23 km2 in FG4 and 25.44 km2 in FG1 indicate an extremely high level of grassland fragmentation. The m eff method is supported in this study as highly suitable and recommended for long-term monitoring of grasslands in the Canadian Prairies; it can help set measurable targets and/or limits for regions to guide management efforts and as a tool for performance review of protection efforts, for increasing awareness, and for guiding efforts to minimize grassland fragmentation. This approach can also be applied in other parts of the world and to other ecosystems.  相似文献   

11.
The contribution of wastewater from a tannery industry to the pollution of a stream was investigated. The main parameters studied were biochemical oxygen demand, chemical oxygen demand, chromium, dissolved oxygen, fecal and total coliforms, nitrogen, oils and greases, pH, phosphorous, sulfides, suspended solids, turbidity, and volatile solids. Three sampling points were located: (1) at the discharge point of tannery wastewater, (2) 50 m upstream, and (3) 80 m downstream of discharge point. Also was investigated the pollution at the stream source.  相似文献   

12.
Noise mapping has been used as an instrument for assessment of environmental noise, helping to support decision making on urban planning. In Brazil, urban noise is not yet recognized as a major environmental problem by the government. Besides, cities that have databases to drive acoustic simulations, making use of advanced noise mapping systems, are rare. This study sought an alternative method of noise mapping through the use of geoprocessing, which is feasible for the Brazilian reality and for other developing countries. The area chosen for the study was the central zone of the city of Sorocaba, located in São Paulo State, Brazil. The proposed method was effective in the spatial evaluation of equivalent sound pressure level. The results showed an urban area with high noise levels that exceed the legal standard, posing a threat to the welfare of the population.  相似文献   

13.
This article extends previous sustainability literature by demonstrating the effectiveness of good governance in rebalancing the economic, environmental, and social components of sustainable development. Good economic, political, and institutional governance are considered as conditional variables, which allow rebalancing these three components in the case of 20 selected MENA economies for the period 1996–2014. Using simultaneous-equation modeling approach, we find that (i) political and institutional governance positively contribute to the three components of sustainable development; (ii) there exists a two-way linkages between human development and economic growth, meaning that they are interrelated and may very well serve as complements to each other; (iii) increased economic growth conducts to further emissions, which, in turn, decreases economic growth; (iv) enhancing human development conducts to a reduction in carbon dioxide emissions, which, in turn, negatively affects human development; (v) improving both political and institutional governance permits MENA governments to moderate both the negative impacts of carbon emissions on economic growth and human development and the positive impact of economic growth on increasing emissions, and as a result sustainable development.  相似文献   

14.
A model of pesticide transport through the soil profile based on clearance and fugacity paradigms is presented, and an example of its application in a GIS environment is shown. A validation of the model at the field plot scale is presented using data obtained at a crop in a semiarid irrigated agricultural basin which was treated with Lindane. The adequacy at the regional scale is tested by inspection of the model predictions and the measured concentrations of the pesticide obtained from a regional phreatimetric net. The clearance concept is used to obtain estimates of the volumes of some environmental phases. These are further used to solve the equations of thermodynamic equilibrium at equal fugacity and obtain concentration estimates. The model closely reproduces the observed percolation trends, and is consistent with the regional pattern of Lindane distribution in groundwater. An application of the model as unitary module for the simulation of non‐point pesticide sources in a raster GIS frame is shown. Its performance (run time, data needed, etc.) is comparable to that of other existing algorithms, and presents some advantages to planners and evaluators of environmental quality in that it incorporates an explicit 2‐D approach and allows the identification of polluted areas downslope with respect to those directly treated with the pesticides. Further, it can be implemented in a variety of GIS and spatial data processors.  相似文献   

15.
If there are no doubts that we must reduce the total emission of carbon dioxide, then the problem of how much different countries should be allowed to contribute to this amount remains a serious one. We suggest this problem to be considered as a non-antagonistic game (in Germeier's sense). A game of this kind is called an “emission game”. Suppose that there are n independent actors (countries or regions), each of them releasing a certain amount of CO2 per year (in carbon units) into the atmosphere, and that the emission would be reduced by each actor. Each actor has his own aim: to minimise the loss in the Gross Domestic Product (GDP) caused by the reduction of emissions. On the other hand, taking into account that it is impossible to estimate more or less precisely the impact of the climate change on GDP for each country today, a common strategy will be to reduce the climate change. Since one of the main leading factors in global warming is the greenhouse effect, then the common aim will be to reduce the sum of emissions. This is a typical conflict situation. How to resolve it? We can weigh the “egoistic” and “altruistic” criteria for each actor introducing the so-called “coefficients of egoism”. This coefficient is very large, if the actor uses a very egoistic strategy, and conversely, if the actor is a “super-altruist”, then the corresponding coefficient is very small. Using these coefficients we get the general solution of the game in a form of some Pareto's equilibrium. The solution is stable and efficient.  相似文献   

16.
This paper discusses why estimates of the benefits of reduced air pollution differ in accordance with the approach used. Estimates based on bottom-up studies of the damage costs related to air pollution usually turn out much lower than estimates based on assessments of the utility of reduced air pollution, obtained for instance by willingness to pay assessments. This is usually explained by the fact that the willingness to pay approach includes the utility aspect of non-market values, and for this reason, it is often preferred to the damage cost approach. This is, however, not the whole story. The paper shows why alternative approaches should not be considered as being in conflict, but rather as means to get supplementary information necessary to put a value on environmental quality. Information from bottom-up assessments of damage costs and from studies of the willingness to pay is used in a macroeconomic model to carry out an evaluation of the social costs of energy saving measures in Hungary.  相似文献   

17.
This research evaluates the importance and effectiveness of Environmental Impact Assessment (EIA) within wind farm planning debates, drawing on insights from case studies in Scotland. Despite general public support for renewable energy on the grounds that it is needed to tackle climate change and implement sustainable development, many proposed wind farms encounter significant resistance. The importance of planning issues and (EIA) processes has arguably been overlooked within recent wind farm social acceptability discourse. Through semi-structured interviews with key stakeholders and textual analysis of EIA documents, the characteristics of EIA are assessed in terms of its perceived purpose and performance. The data show that whilst respondents perceive EIA to be important, they express concerns about bias and about the inability of EIA to address climate change and wind farm decommissioning issues adequately. Furthermore, the research identifies key issues which impede the effectiveness of EIA, and reveals differences between theoretical and practical framings of EIA. The paper questions the assumption that EIA is a universally applicable tool, and argues that its effectiveness should be analysed in the context of specific development sectors. The article concludes by reviewing whether the recently amended EIA Directive (2014/52/EU) could resolve identified problems within national EIA practice.  相似文献   

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The US Environmental Protection Agency maintains networks of pollution monitors for two basic purposes: to check and enforce the attainment of national ambient air quality standards (NAAQS) and to provide useful data for studying pollution and its effects. These purposes imply conflicting criteria for the locations of a limited number of monitors. To check the attainment of standards, monitors are placed where pollution levels are highest. Monitors are not required where standards have always been met and there are no new pollution sources. To provide useful data for studying pollution and its effects, monitors would be placed to observe outcomes under a variety of pollution levels. This study asks the following questions. What factors affect when a monitor is retired from the network? What drives the decision to add a new site? What causes year-to-year changes in the number of monitors? We tackle these questions with a particular focus on the role of regulatory compliance and pollution levels in the context of monitors for tropospheric ozone (O3). Using a panel dataset of monitors in the contiguous US spanning the years 1993 to 2011, we find that the peak O3 readings in the prior period are significantly associated with the regulator’s decision of whether to add or to drop a monitor in the following period. While compliance with the NAAQS for O3 is not consistently associated with network composition, compliance with the PM2.5 NAAQS does appear to affect changes to the network.  相似文献   

20.
Hunting is a problem to animal conservation in different parts of the world and it has caused the local extinction of several species. The aim of this study was to characterize the poaching activities in one of the main tabuleiro forest remnants of Brazil, the Linhares-Sooretama Block (LSB). Poaching records from 2010 to 2013 were gathered from the agencies responsible for monitoring and combating environmental crimes in the LSB. A total of 693 records (mean = 173 events/year) were collected involving direct (hunted animals, firearms, handmade firearms, traps, poachers, and various hunting supplies) and indirect (tree stands, baits, and poacher signs) evidences of poaching. No differences in the monthly cumulative number of records were found among years, but the distribution of records differed according to the type of evidence. A total of 40 animal seizure events were recorded involving a total of at least 15 taxa directly affected by poaching (reptiles = 2, birds = 6, mammals = 7) and 75 individuals seized (19 individuals/year). Five of the poached species are threatened. Lowland paca (Cuniculus paca) and armadillos were the most poached mammals in the region. Most of the poachers conduct such activities for fun (entertainment) and/or professionally (commercial hunting). The collected data show an approximately 32% increase in the number of poaching events in the region compared with the historical data available for LSB. It may have resulted from a gradual decrease in protection, both in terms of the number of agents deployed and the levels of effort of the teams, which began in 2009. The data demonstrate that poaching is a significant threat to the conservation of the LSB fauna, as it is in other Atlantic Forest remnants and in other regions of the world. Protection activities must be intensified to effectively combat the impacts of poaching in the LSB region, thereby contributing to the conservation of species in one of the few Atlantic Forest remnants whose original species composition still remains intact.  相似文献   

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