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1.
The deposition processes in Kerkini Reservoir, since 1933, are examined in this paper. Built on the course of River Strymonas at the plain of Serres for anti-flooding control, it was gradually developed as a multipurpose reservoir for irrigation and a very important international wetland protected by the Ramsar Treaty. The deposition into Lake Kerkini is caused by the high rates of sediment transport by River Strymonas from the Bulgarian, Serbian and Former Yugoslav Republic of Macedonia territory drainage basin of Kerkini of 11,600 km2. The life expectancy of the original reservoir was approximately 40 years. The sediment transport and the deposition volumes and rates were high during the first stages of Kerkini operation due to deforestations and stockbreeding activities against forested and agricultural areas in southwestern Bulgaria before World War II, which intensify erosion and deposition phenomena in Kerkini’s catchment. They were gradually reduced due to the anti-erosion hydraulic works, extended reforestations mainly in the period 1962–1977, and the natural processes of Strymonas–Kerkini hydrosystem to attain its equilibrium. Based on six systematic bottom surveys of the reservoir from 1933 to 1991, two empirical formulas of the total deposition volume (ΣV s) and the deposition rates (ΔΣV s/ΔΣt) through time (Σt) were developed. The results have been compared with other catchments of the broader Balkan area concerning the erosion, sediment yield, sediment deposition volumes, and rates, and it was found in accordance with the measured data. The obtained empirical model was used to estimate the life expectancy of the new rebuilt reservoir of Kerkini in 1984; in the case of natural processes, these do not change dramatically in the transboundary Lake Kerkini catchment. The deposition processes of Kerkini were the major causes of its development into an internationally important wetland and biotope. Kerkini offers development opportunities for scientific research, environmental education, ecotourism, and recreation activities.  相似文献   

2.

This study evaluates the socioeconomic risk that extreme El Niño event-related road damages present to Peru by combining an environmental modelling of events’ occurrences in the country with a quantitative modelling of their effects on its economy. The dynamic of occurrence of events is modelled as a stochastic process with a vector autoregressive representation based on historical climatic data, and simulated over a 10-year period with a non-parametric bootstrap procedure. The indirect consequences of events’ related road damages are addressed with a multiregional dynamic computable general equilibrium model through an increase in interregional transportation costs and, more originally, a negative externality effect on activities’ output, which is estimated beforehand using a firm database. We find that extreme El Niño events constitute a significant one-off disaster risk for the country, threatening shifts of???2.8% in GDP and?+?1.9% in poverty rates with an annual probability p?=?1.4%. We further show that they also present a longer-term risk, leading to average annual deviations from normal trend by???0.8% in GDP and?+?0.4% in poverty rate with a probability p?=?12.6% over a 10-year period. However, we finally show that Peru might reduce these socioeconomic risks associated with these non-frequent but recurrent climatic shocks in constructing more disaster-resilient road infrastructure.

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3.
Urbanization produced significant landscape changes throughout the world. China has been experiencing accelerated urbanization during the past decades. Rapid land use/land over conversion occurred nationwide in urbanization, manifesting noteworthy characteristics of landscape dynamics. In this study, we investigated the spatial differentiation in settlement change rates among 1-km2 land units in the Nanjing metropolitan region, a representative rapidly urbanizing region in China. Remotely sensed detection using Landsat TM data of 1988–2006 showed that settlement increase, termed as positive growth (PG), was predominant in the study area; while settlement decrease, termed as negative growth (NG), also had a considerable proportion, which was mainly attributed to the increase of green lands and the shrink of rural settlements. Along the urban-rural gradient, PG and NG showed similar mono-peaked patterns. The urban fringe zone with a consistent width of about 4 km was identified as the hot zone of both PG and NG over the three unequal periods. For both PG and NG, high-rated changes tended to exhibit more aggregative patterns along the gradient in the urban fringe zone. Settlement changes showed apparent anisotropy across directions. The directional distribution of PG was significantly negatively correlated to the topographic variables, suggesting that the mountains constrained urban expansion in an “area-weighted inverse-distance power” form. Significant correlation between PG and NG in a time-lagged manner showed the “increase–decrease” fluctuation occurred in settlement changes, reflecting the “urban expansion–land reconfiguration” process in rapid urbanization in Nanjing.  相似文献   

4.

We design an induced value laboratory consumption choice experiment where complex tariff schemes trigger nonlinear simplification heuristics that lead individuals to over- or underconsume public goods such as electricity, gas, or drinking water. By studying this “schmeduling” bias, we investigate how an informational nudge could reduce it. Participants choose consumption levels repeatedly under different tariff schemes, where the marginal price per unit either remains constant (constant block rate, i.e., CBR) or increases above a certain threshold (increasing block rate, or IBR). We observe that the vast majority of choices are optimal, but a significant number of them reveal overconsumption. To investigate the impact of the informational nudge on these errors, some of our participants received a marginal price reminder. In that case, the learning effect helps to achieve convergence towards the optimal consumption value. To explain these effects, we use econometric models relying on microeconomic behavioral inattention to price to capture the magnitude of consumers’ inattention, observing, in particular, how the informational nudge is decreasing it.

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5.
Assessing Multi-site Drought Connections in Iran Using Empirical Copula   总被引:1,自引:0,他引:1  
Drought is a multi-dimensional natural hazard with stochastic characteristics usually related to each other. Separate univariate statistical models cannot capture the important relationships among drought characteristics, that is, severity and duration. In this study, an empirical copula is employed to construct a bivariate model of droughts, where droughts are defined as continuously negative standardized precipitation index (SPI) periods with one SPI value reaching ?1 or less. Bivariate frequency analyses in terms of recurrence intervals are performed using the established empirical copula-based bivariate drought model. The inter-connection among different regions of droughts is explored by a lower tail dependence coefficient. A nonparametric estimation based on an empirical copula is employed pairwisely to calculate the lower tail dependence coefficient among stations. The proposed method is applied to six rainfall gauge stations in Iran to explore drought properties of single sites as well as the inter-connection among multi-sites. The results show that greater mean drought severity and duration are associated with the least arrival rate of drought events, which occurs at the Ahwaz station. The tail dependence analysis reveals that distance between stations is not a key parameter. Generally, the Ahwaz and Isfahan stations have the highest probability of simultaneous droughts among the six stations.  相似文献   

6.

In this paper, we propose a simple oligopoly game model to represent the interactions between coalitions of countries in deploying carbon dioxide removal (CDR) strategies in a steady-state net-zero emission climate regime that could take place by the end of the twenty-first century. The emission quotas and CDR activities obtained in the solution of this steady-state model could then be used as a target for end-of-period conditions in a dynamic integrated assessment analysis studying the transition to 2100. More precisely, we analyze a steady-state situation where m coalitions exist and behave as m players in a game of supplying emission rights on an international emission trading system. The quotas supplied by a coalition must correspond to the amount of CO2 captured through CDR activities in the corresponding world region. We use an extension of the computable general equilibrium model GEMINI-E3 to calibrate the payoff functions and compute an equilibrium solution in the noncooperative game.

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7.

Three-dimensional (3D) models are often utilised to assess the presence of sand and gravel deposits. Expanding these models to provide a better indication of the suitability of the deposit as aggregate for use in construction would be advantageous. This, however, leads to statistical challenges. To be effective, models must be able to reflect the interdependencies between different criteria (e.g. depth to deposit, thickness of deposit, ratio of mineral to waste, proportion of ‘fines’) as well as the inherent uncertainty introduced because models are derived from a limited set of boreholes in a study region. Using legacy borehole data collected during a systematic survey of sand and gravel deposits in the UK, we have developed a 3D model for a 2400 km2 region close to Reading, southern England. In developing the model, we have reassessed the borehole grading data to reflect modern extraction criteria and explored the most suitable statistical modelling technique. The additive log-ratio transform and the linear model of coregionalization have been applied, techniques that have been previously used to map soil texture classes in two dimensions, to assess the quality of sand and gravel deposits in the area. The application of these statistical techniques leads to a model which can be used to generate thousands of plausible realisations of the deposit which fully reflect the extent of model uncertainty. The approach offers potential to improve regional-scale mineral planning by providing an enhanced understanding of sand and gravel deposits and the extent to which they meet current extraction criteria.

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8.
This paper argues on both theoretical and empirical grounds that, beyond a certain point, there is an unavoidable conflictbetween economic development (generally taken to mean 'materialeconomic growth') and environmental protection. Think for a moment of natural forests, grasslands, marine estuaries, salt marshes, and coral reefs; and of arable soils, aquifers, mineraldeposits, petroleum, and coal. These are all forms of 'natural capital' that represent highly-ordered self-producing ecosystemsor rich accumulations of energy/matter with high use potential (low entropy). Now contemplate despoiled landscapes, eroding farmlands, depleted fisheries, anthropogenic greenhouse gases,acid rain, poisonous mine tailings and toxic synthetic compounds.These all represent disordered systems or degraded forms of energy and matter with little use potential (high entropy). The main thing connecting these two states is human economic activity. Ecological economics interprets the environment-economyrelationship in terms of the second law of thermodynamics. The second law sees economic activity as a dissipative process. Fromthis perspective, the production of economic goods andservices invariably requires the consumption of available energy and matter. To grow and develop, the economynecessarily 'feeds' on sources of high-quality energy/matter first produced by nature. This tends to disorder and homogenizethe ecosphere, The ascendance of humankind has consistently been accompanied by an accelerating rate of ecological degradation, particularly biodiversity loss, the simplificationof natural systems and pollution. In short, contemporary political rhetoric to the contrary, the prevailing growth-oriented global development paradigm is fundamentally incompatible with long-term ecological and social sustainability. Unsustainability is not a technical nor economic problem as usually conceived, but rather a state of systemic incompatibilitybetween a economy that is a fully-contained, growing, dependent sub-system of a non-growing ecosphere. Potential solutions fly inthe face of contemporary development trends and cultural values.  相似文献   

9.

We examine the dynamic relationships between per capita carbon dioxide emissions, real gross domestic product (GDP), non-hydroelectric renewable energy (NHRE) consumption, agricultural value added (AVA), and agricultural land (AGRL) use for the case of Argentina over the period 1980–2013 by employing the autoregressive distributed lag bound approach to cointegration and Granger causality tests. The Fisher statistics of the Wald test are examined, and the existence of a long-run cointegration between variables is proved. There are long-run bidirectional causalities between all considered variables. The short-run Granger causality suggests bidirectional causality between AVA and agricultural land use, unidirectional causalities running from AGRL to NHRE and from NHRE to AVA. Long-run elasticity estimates suggest that increasing AGRL reduces carbon emissions; increasing AVA increases GDP and reduces pollution, AGRL, and NHRE; and increasing NHRE reduces AVA and AGRL. Thus, it seems that agriculture and renewable energy are substitute activities and compete for land use. We recommend that Argentina should continue to encourage agricultural production. The substitutability between agricultural and non-hydroelectric renewable energy productions, and their competition for agricultural land use, should be at least reduced or even stopped by encouraging research and development in second-generation (or even in third-generation) biofuel production and in new technologies for renewable energy and for agriculture more efficient in land use.

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10.

Genetically modified crops (GMCs) and climate change have been two ecological issues intensely debated over the years. The search for global solutions to the effects of climate change on agriculture has led to the proposal of GMCs as a tool to reduce the environmental impact of agricultural practices and to improve their efficiency of production. At least 27 countries, all over the world, have cultivated GMCs. The purpose of the present paper is to provide insights about the possible linkages between the cultivated areas and the CO2 emissions in these countries. In addition, the study intends to establish meaningful relationships between attributes related to the particular socio-economic situations and the environmental impacts of GMCs. Some examples are the connection between acreages of GMCs and the status of each country with respect to the Cartagena Protocol on Biosafety, as well as their classification according to the mean income per capita and their CO2 emissions. In order to give the mathematical support to these links, the methodology known as Order Theory was employed. The results show that Paraguay, India, Burkina Faso, Brazil and Pakistan could be the best contributors to the mitigation of the climate change by the reduction of their CO2 emission levels through GMCs.

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11.
The rates of desorption of trichloroethylene (TCE) and 1,3-dichlorobenzene (DCB) from a silty soil at a Superfund site and a silty-clayey soil from an uncontaminated bottomland hardwoodswamp in Baton Rouge, Louisiana were studied in laboratory batchsystems. The effect of the age of soil contamination was studiedusing a laboratory-spiked soil incubated for 3 days, 3 months and5 months. An empirical non-linear model was used to describe thebi-phasic nature of desorption with one fraction (labile) beingreleased in relatively short periods of time (typically 24–100 hr) and a second fraction (non-labile or irreversible) beingresistant to desorption. The non-linear model parameters, viz.,the fraction of the chemical released rapidly (F), and the firstorder desorption rate coefficients, k 1 and k 2respectively for the labile and slowly released fractions weredetermined by fitting the experimental data to the model. Thedata fit the model well as indicated by the high r 2 values.The estimate of k 1 was good. However, the values of k 2are known with less precision due to the limited duration of theexperiment and number of samples taken at long times. In addition, desorption kinetics of 3 and 5-month old contaminatedsoils showed that progressively less amount of contaminant was available for facile desorption (lower F) compared to freshly contaminated soil. The labile fraction had desorption rate constants of the order of 10-1 h-1, whereas the slowlyreleased fraction had rate constants of the order of 10-4 h-1 in accord with literature reported values for a varietyof other compounds and soils. Possible mechanisms describing these rates and implications for the site clean up are discussed.  相似文献   

12.
Offshore wind farm developments may impact protected marine mammal populations, requiring appropriate assessment under the EU Habitats Directive. We describe a framework developed to assess population level impacts of disturbance from piling noise on a protected harbour seal population in the vicinity of proposed wind farm developments in NE Scotland. Spatial patterns of seal distribution and received noise levels are integrated with available data on the potential impacts of noise to predict how many individuals are displaced or experience auditory injury. Expert judgement is used to link these impacts to changes in vital rates and applied to population models that compare population changes under baseline and construction scenarios over a 25 year period. We use published data and hypothetical piling scenarios to illustrate how the assessment framework has been used to support environmental assessments, explore the sensitivity of the framework to key assumptions, and discuss its potential application to other populations of marine mammals.  相似文献   

13.

This document proposes a new indicator to assess countries’ sustainability. The indicator synthetises measures of economic and ecological efficiency. In other words, we assess the ability of countries to use resources to produce the maximum possible amounts of goods and services while keeping production activities’ impact on the environment as low as possible. The measure of ecological efficiency is the ecological reserve/deficit (ERD), which is based on the concept of ecological footprint. The new indicator is computed using the data envelopment analysis (DEA) model, a well-known non-parametric technique that delivers measures of productive efficiency by comparing outputs to inputs used in production. We modify the standard DEA model in two ways. Firstly, we allow for negative input and output data. Secondly, to increase DEA discriminating power of countries, we compute anti-efficiency measures. This allows us to obtain a ranking of countries based on the best and worst performances. Results show that the new efficiency indicator is valid and that high ERD positively influences the ranking of countries. Introducing anti-efficiency provides more plausible results and a more accurate ranking, for example high-polluting countries like China previously economically efficient are now ranked as low efficient when sustainability is taken into account.

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14.

We propose a novel framework for the economic assessment of environmental policy. Our main point of departure from existing work is the adoption of a satisficing, as opposed to optimizing, modeling approach. Along these lines, we place primary emphasis on the extent to which different policies meet a set of goals at a specific future date instead of their performance vis-a-vis some intertemporal objective function. Consistent to the nature of environmental policymaking, our model takes explicit account of model uncertainty. To this end, the decision criterion we propose is an analog of the well-known success-probability criterion adapted to settings characterized by model uncertainty. We apply our criterion to the climate-change context and the probability distributions constructed by Drouet et al. (2015) linking carbon budgets to future consumption. Insights from computational geometry facilitate computations considerably and allow for the efficient application of the model in high-dimensional settings.

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15.
Factor-Augmenting Technical Change: An Empirical Assessment   总被引:1,自引:0,他引:1  
This paper estimates factor-specific technical change and input substitution using a structural approach. It contributes to the existing literature by introducing various technology drivers for factor productivities and by assessing the impact of endogenous technical change on the elasticity of substitution. The empirical results suggest that factor productivities are indeed endogenous. In addition, technology drivers are factor-specific. Whereas the R&D stock and machinery imports are important determinants of energy and capital productivity, the education stock is statistically related to labour productivity. The rate of energy-augmenting technical change is larger than that of either labour or capital. By contrast, the productivity of these two factors grows at similar rates. Estimates of the elasticity of substitution are within the range identified by previous literature. In addition, we show that endogenous technical change reduces substitution. Because the elasticity of substitution is lower than one, knowledge and human capital can ultimately have an energy-using effect. The estimated structure of endogenous technical change suggests that Integrated Assessment models focusing on energy-saving technical change might underestimate climate policy costs.  相似文献   

16.
The article presents a procedure for assessing the quality of the environment, using eggshells of birds as a biomarker implemented into a Bayesian network. An environmental quality index (EQI) was proposed and calculated on the basis of local quality indicators. Experimental data on concentrations of toxic elements in grey heron (Ardea cinerea) eggshells (biomarker of river valleys) were used to determine the empirical variables (nodes) and the probability distributions on the set of these variables. A probabilistic graphical model represents a multitude of relationships between variables in a system that enables the prediction of EQI. The model presented is a useful tool for environmental quality management.  相似文献   

17.
18.
Anthropogenic forces that alter the physical landscape are known to cause significant soil erosion, which has negative impact on surface water bodies, such as rivers, lakes/reservoirs, and coastal zones, and thus sediment control has become one of the central aspects of catchment management planning. The revised universal soil loss equation empirical model, erosion pins, and isotopic sediment core analyses were used to evaluate watershed erosion, stream bank erosion, and reservoir sediment accumulation rates for Ni Reservoir, in central Virginia. Land-use and land cover seems to be dominant control in watershed soil erosion, with barren land and human-disturbed areas contributing the most sediment, and forest and herbaceous areas contributing the least. Results show a 7 % increase in human development from 2001 (14 %) to 2009 (21.6 %), corresponding to an increase in soil loss of 0.82 Mg ha-1 year-1 in the same time period. 210Pb-based sediment accumulation rates at three locations in Ni Reservoir were 1.020, 0.364, and 0.543 g cm-2 year-1 respectively, indicating that sediment accumulation and distribution in the reservoir is influenced by reservoir configuration and significant contributions from bedload. All three locations indicate an increase in modern sediment accumulation rates. Erosion pin results show variability in stream bank erosion with values ranging from 4.7 to 11.3 cm year-1. These results indicate that urban growth and the decline in vegetative cover has increased sediment fluxes from the watershed and poses a significant threat to the long-term sustainability of the Ni Reservoir as urbanization continues to increase.  相似文献   

19.
A probability-based sample of 48 of the 152 lakes in the Sawtooth Wilderness, Idaho was conducted in summer 1988. Results from this sample were compared to the Environmental Protection Agency's 1985 probability survey of lakes throughout the western United States, which included 17 lakes in the Sawtooth Wilderness. Although methods differed in several respects, including year, season, sampling location within the lakes, holding times, and sample size, general characterization of lake chemistry for the population of lakes in the wilderness based on the two surveys was very similar. The results indicate that general lake characterization in difficult-to-access wilderness areas of the West can be achieved with a modest investment in resources with the use of volunteers. However, accurate measurement of some non-conservative and low-level analytes such as NO 3 ,NH 4 + , total P, and aluminiun in the lakes probably requires more rigorous attention to sampling protocols and holding times. A two-stage sampling strategy employing extensive use of conductivity on a large number of lakes and intensive detailed chemical characterization on a smaller number of lakes offers an alternative design for describing large populations of wilderness lakes. The relatively high concentrations of fluoride and sulfate in many of the study lakes reflect the weathering of minerals not usually identified on geologic maps. These natural sources of acid anions violate the assumptions in commonly employed empirical models of acidification.  相似文献   

20.
Ethyl(2-ethylamino)thiophenol-2,6-pyridinedicarboxylate (ETPD) was synthesized from the reaction of disodium pyridine-2,6-dicarboxylate with 1,2-dibromoethane in methanol, followed by treatment with 2-aminothiophenol. The spectral characterization of ETPD is described in detail. This electron-donating agent was successfully utilized for simultaneous enrichment of ultra trace levels of copper and lead in a wide variety of samples. By passing the aqueous solutions through octadecylsilyl bonded phase membrane disks impregnated with 12 mg of ETPD at flow rates of 45 mL min?1, Cu and Pb were selectively trapped on the disk surface over the pH range 3.0 to 7.0, whereas most other ions were negligibly retained. Numerous chemical parameters affecting sorption and subsequent elution were also investigated. The target ions were stripped from the disk surfaces by reverse flow, at rates of 12 mL min?1, and were immediately introduced to the nebulizer of an atomic absorption spectrometer. This inexpensive and off-line method offers enrichment factors of 400 and 300 and detection limits of 2.5 and 0.2 μg L?1 for copper and lead, respectively. The potential applicability of the method was confirmed by its reliable use in quantification of these elements in some real water samples, industrial effluents, three tea samples and peppers, as well as by comparison with graphite furnace atomic absorption spectrometric determinations.  相似文献   

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