ABSTRACT: The vulnerability of wetlands to changes in climate depends on their position within hydrologic landscapes. Hydrologic landscapes are defined by the flow characteristics of ground water and surface water and by the interaction of atmospheric water, surface water, and ground water for any given locality or region. Six general hydrologic landscapes are defined; mountainous, plateau and high plain, broad basins of interior drainage, riverine, flat coastal, and hummocky glacial and dune. Assessment of these landscapes indicate that the vulnerability of all wetlands to climate change fall between two extremes: those dependent primarily on precipitation for their water supply are highly vulnerable, and those dependent primarily on discharge from regional ground water flow systems are the least vulnerable, because of the great buffering capacity of large ground water flow systems to climate change. 相似文献
One strategy to combat nitrate (NO3-N) contamination in rivers is to understand its sources. NO3-N sources in the East Tiaoxi River of the Yangtze Delta Region were investigated by applying a 15N–18O dual isotope approach. Water samples were collected from the main channel and from the tributaries. Results show that high total N and NO3-N are present in both the main channel and the major tributaries, and NO3-N was one of the most important N forms in water. Analysis of isotopic compositions (δ18O, δD) of water suggests that the river water mainly originated from three tributaries during the sampling period. There was a wide range of δ15N-NO3 (?1.4 to 12.4 ‰) and a narrow range of δ18O-NO3 (3.7 to 9.0 ‰) in the main channel waters. The δ15N and δ18O-NO3 values in the upper, middle, and lower channels along the river were shifted as 8.2, 3.5, and 9.5 ‰, and 9.0, 4.2, and 6.0 ‰, respectively. In the tributary South Tiao, the δ15N and δ18O-NO3 values were as high as 9.5 and 7.0 ‰, while in the tributaries Mid Tiao and North Tiao, NO3-N in most of the samples had relatively low δ15N and δ18O-NO3 values from 2.3 to 7.5 ‰ and 4.7 to 7.0 ‰, separately. Our results also suggest that the dual isotope approach can help us develop the best management practice for relieving NO3-N pollution in the rivers at the tributary scale. 相似文献
Sustainability indicators are well recognized for their potential to assess and monitor sustainable development of agricultural systems. A large number of indicators are proposed in various sustainability assessment frameworks, which raises concerns regarding the validity of approaches, usefulness and trust in such frameworks. Selecting indicators requires transparent and well-defined procedures to ensure the relevance and validity of sustainability assessments. The objective of this study, therefore, was to determine whether experts agree on which criteria are most important in the selection of indicators and indicator sets for robust sustainability assessments. Two groups of experts (Temperate Agriculture Research Network and New Zealand Sustainability Dashboard) were asked to rank the relative importance of eleven criteria for selecting individual indicators and of nine criteria for balancing a collective set of indicators. Both ranking surveys reveal a startling lack of consensus amongst experts about how best to measure agricultural sustainability and call for a radical rethink about how complementary approaches to sustainability assessments are used alongside each other to ensure a plurality of views and maximum collaboration and trust amongst stakeholders. To improve the transparency, relevance and robustness of sustainable assessments, the context of the sustainability assessment, including prioritizations of selection criteria for indicator selection, must be accounted for. A collaborative design process will enhance the acceptance of diverse values and prioritizations embedded in sustainability assessments. The process by which indicators and sustainability frameworks are established may be a much more important determinant of their success than the final shape of the assessment tools. Such an emphasis on process would make assessments more transparent, transformative and enduring. 相似文献
Environmental Science and Pollution Research - Bioreduction of selenium oxyanions to elemental selenium is ubiquitous; elucidating the properties of this biogenic elemental selenium (BioSe) is thus... 相似文献
The effectiveness of environmental protection measures is based on the early identification and diagnosis of anthropogenic pressures. Similarly, restoration actions require precise monitoring of changes in the ecological quality of ecosystems, in order to highlight their effectiveness. Monitoring the ecological quality relies on bioindicators, which are organisms revealing the pressures exerted on the environment through the composition of their communities. Their implementation, based on the morphological identification of species, is expensive because it requires time and experts in taxonomy. Recent genomic tools should provide access to reliable and high-throughput environmental monitoring by directly inferring the composition of bioindicators’ communities from their DNA (metabarcoding). The French-Swiss program SYNAQUA (INTERREG France-Switzerland 2017–2019) proposes to use and validate the tools of environmental genomic for biomonitoring and aims ultimately at their implementation in the regulatory bio-surveillance. SYNAQUA will test the metabarcoding approach focusing on two bioindicators, diatoms, and aquatic oligochaetes, which are used in freshwater biomonitoring in France and Switzerland. To go towards the renewal of current biomonitoring practices, SYNAQUA will (1) bring together different actors: scientists, environmental managers, consulting firms, and biotechnological companies, (2) apply this approach on a large scale to demonstrate its relevance, (3) propose robust and reliable tools, and (4) raise public awareness and train the various actors likely to use these new tools. Biomonitoring approaches based on such environmental genomic tools should address the European need for reliable, higher-throughput monitoring to improve the protection of aquatic environments under multiple pressures, guide their restoration, and follow their evolution. 相似文献
Objective: Adaptive cruise control (ACC), a technology that allows for automated car following, is becoming increasingly prevalent. Previous surveys have shown that drivers generally regard ACC as pleasant but that they have to intervene when the ACC reaches its operational limits. The former research has been mostly concerned with specific car brands and does not fully reflect the diversity of ACC types in traffic today. The objective of the present research was to establish the determinants of pleasure in using ACC.
Methods: A 55-item online questionnaire was completed by Dutch users of diverse ACC systems.
Results: Respondents (N = 182) rated their ACC highly, with a mean score of 8.0 on a scale from 1 (extraordinarily negative) to 10 (extraordinarily positive) and were most pleased with ACC on high-speed roads and in low-density traffic. Moreover, the findings point to specific operational limits such as associated with cut-in situations. Pleasure was greater for the types of ACC that are able to decelerate to a full stop, according to 48% of our sample. An analysis of the free-response items indicated that respondents who were displeased with ACC mentioned its occasional clumsiness and the dangerous situations it may evoke, whereas those who were pleased with ACC valued the complementarity of human and machine and emphasized the roles of responsibility and experience in using ACC.
Conclusion: Pleasure in using ACC is a function of both technological advances and human factors. 相似文献
In this study, different pretreatment strategies of sugarcane bagasse prior to citric acid modification were investigated in terms of Pb2+ adsorption capacity. Pretreatment strategies included the use of NaOH, HCl, and C2H5OH in various concentrations. In order to fundamentally understand how these pretreatment methods affect the modification of sugarcane bagasse by citric acid as well as the Pb2+ adsorption capacity of sugarcane bagasse, three main components of sugarcane bagasse namely cellulose, hemicellulose, and lignin were isolated and esterified by citric acid under the same conditions. ATR-FTIR, XPS, SEM, and an analysis of the number of carboxylic acid groups were used to investigate the physicochemical and chemical properties of the materials. These three components were proved to participate in adsorption and induce the esterification with citric acid. Hence, pretreatment with ethanol and 0.01 M NaOH which could retain cellulose, hemicellulose, and lignin in sugarcane bagasse achieved a high Pb2+ adsorption capacity, i.e., 122.4 and 97 mg/g after the esterification with citric acid. In contrast, pretreatment with 0.5 M NaOH and 0.1 M HCl removed lignin and hemicellulose, leading to the lowest value of approximately 45 mg/g for citric acid esterified-pretreated sugarcane bagasse. XPS analysis and number of carboxylic group measurement confirmed the esterification between bagasse and citric acid. To understand the adsorption mechanism of adsorbent, two kinetic models including pseudo-first-order model and pseudo-second-order model were applied. The experimental data were well described by the pseudo-second-order model. The adsorption isotherm data were fitted Langmuir and Freundlich.
Several global corporations have been severely criticized by different lobbying groups for the impact of their operations on the natural environment and on the local communities. Because corporate operations cannot be studied in isolation but rather as a part of a large network often referred to as a supply chain, this paper investigates the potential link between supply chain characteristics and sustainable development at the country level. In particular, the linkage between supply chain strength, generally defined as the number and quality of the suppliers and customers in a country, and the three dimensions of sustainable development namely environmental performance, corporate environmental practices, and social sustainability is assessed. Using archival data from The Global Competitiveness Report (2004–2005) and the 2005 Environmental Sustainability Index, a statistical assessment of the linkage was conducted. The results indicate that supply chain strength is positively linked to all three dimensions of sustainable development. 相似文献