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91.
Gisser and Sánchez (Water Resour Res 16(4):638–642, 1980) compared two different strategies to manage aquifers: “free market” and policy regulation. They stated that the outcome of both is practically the same, and that policy regulation could not improve social welfare. This study challenges this argument by analyzing the management strategies in two large aquifers located in southern Spain, the Eastern La Mancha and the Western La Mancha aquifers. The appeal of this case stems from the fact that management of the Eastern La Mancha aquifer is almost sustainable. In stark contrast, its neighboring Western La Mancha aquifer is being grossly mismanaged. The results engage two major questions from previous groundwater literature. The first question is whether or not aquifer management requires policy intervention. The answer depends upon the consideration and magnitude of environmental damages in the model. The second question addresses the nature of groundwater policies. The contrast in management outcomes between the Western and the Eastern La Mancha aquifers is related to the different types of policy instruments implemented for each aquifer. The results of these policies underline the importance of nurturing the stakeholders’ collective action under the appropriate institutional setting.  相似文献   
92.
The objective of this study was to elaborate a series of mathematical models with the aim of short-term prediction of TSP, PM10, As, Cd, Ni and Pb in ambient air. These pollutants depend on some known variables (meteorological variables). The reason for choosing this pollutant type is that particulate matter may present a much higher potential risk despite its low representativeness as compared with the gas pollutant group. A positive correlation between high particle concentrations and deterioration in public health has been shown in recent studies. The elements As, Cd, Ni and Pb in PM10 were also analyzed to determine the toxicity of these particles. The goal is to provide a useful instrument to alert the population facing possible episodes of high concentrations of atmospheric pollutants. The study was carried out in a highly industrialized area in the ceramic cluster of Castellón for 5 years (2001–2005). The origin of the contamination in this area is both natural and anthropogenic. The natural origin is due to the resuspension of mineral materials from the surrounding mountains and from the long-range transport of materials from North Africa. The anthropogenic contamination sources that stand out include the non-metallic mineral material industries (ceramic production), chemical industries (color, frit and enamel manufacturing), as well as vehicular traffic. Once the particle samples were collected in quartz fiber filters, the concentration levels of TSP and PM10 were determined gravimetrically. The chemical analysis of the filters was carried out by ICP-MS. Predictive models have been constructed by using multiple regression analysis together with time series models (ARIMA). The SPSS 14.0 statistical software has been employed to analyze the obtained experimental data.  相似文献   
93.
Equilibrium line altitudes (ELAs) of alpine glaciers are sensitive indicators of climate change and have been commonly used to reconstruct paleoclimates at different temporal and spatial scales. However, accurate interpretations of ELA fluctuations rely on a quantitative understanding of the sensitivity of ELAs to changes in climate. We applied a full surface energy- and mass-balance model to quantify ELA sensitivity to temperature and precipitation changes across the range of climate conditions found in the Andes. Model results show that ELA response has a strong spatial variability across the glaciated regions of South America. This spatial variability correlates with the distribution of the present-day mean climate conditions observed along the Andes. We find that ELAs respond linearly to changes in temperature, with the magnitude of the response being prescribed by the local lapse rates. ELA sensitivities to precipitation changes are nearly linear and are inversely correlated with the emissivity of the atmosphere. Temperature sensitivities are greatest in the inner tropics; precipitation becomes more important in the subtropics and northernmost mid-latitudes. These results can be considered an important step towards developing a framework for understanding past episodes of glacial fluctuations and ultimately for predicting glacier response to future climate changes.  相似文献   
94.
Natural Hazards - In 2018, Lombok island, Indonesia, was hit by a series of destructive earthquakes that caused thousands of casualties and widespread material damage. In response to those events,...  相似文献   
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