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201.
Shadi Dayyani Chandra A. Madramootoo Peter Enright Guillaume Simard Apurva Gullamudi Shiv O. Prasher Ali Madani 《Journal of the American Water Resources Association》2009,45(3):779-792
Abstract: The hydrologic performance of DRAINMOD 5.1 was assessed for the southern Quebec region considering freezing/thawing conditions. A tile drained agricultural field in the Pike River watershed was instrumented to measure tile drainage volumes. The model was calibrated using water table depth and subsurface flow data over a two‐year period, while another two‐year dataset served to validate the model. DRAINMOD 5.1 accurately simulated the timing and magnitude of subsurface drainage events. The model also simulated the pattern of water table fluctuations with a good degree of accuracy. The R2 between the observed and simulated daily WTD for calibration was >0.78, and that for validation was 0.93. The corresponding coefficients of efficiency (E) were >0.74 and 0.31. The R2 and E values for calibration/validation of subsurface flow were 0.73/0.48 and 0.72/0.40, respectively. DRAINMOD simulated monthly subsurface flow quite accurately (E > 0.82 and R2 > 0.84). The model precisely simulated daily/monthly drain flow over the entire year, including the winter months. Thus DRAINMOD 5.1 performed well in simulating the hydrology of a cold region. 相似文献
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203.
Model-based prediction of long-term leaching of contaminants from secondary materials in road constructions and noise protection dams 总被引:1,自引:0,他引:1
Beyer C Konrad W Rügner H Bauer S Liedl R Grathwohl P 《Waste management (New York, N.Y.)》2009,29(2):839-850
In this study, contaminant leaching from three different secondary materials (demolition waste, municipal solid waste incineration ash, and blast furnace slag) to groundwater is assessed by numerical modeling. Reactive transport simulations for a noise protection dam and a road dam (a typical German autobahn), in which secondary materials are reused as base layers, were performed to predict the breakthrough of a conservative tracer (i.e., a salt) and sorbing contaminants (e.g., PAHs like naphthalene and phenanthrene or heavy metals) at the groundwater table. The dam constructions have a composite architecture with soil covers in inclined layers and distinct contrasts in the unsaturated hydraulic properties of the used materials. Capillary barrier effects result in strong spatial variabilities of flow and transport velocities. Contaminant breakthrough curves at the groundwater table show significant tailing due to slow sorption kinetics and a wide distribution of travel times. While conservative tracer breakthrough depends primarily on subsoil hydraulic properties, equilibrium distribution coefficients and sorption kinetics represent additional controlling factors for contaminant spreading. Hence, the three secondary materials show pronounced differences in the temporal development of leached contaminant concentrations with consequences for breakthrough times and peak concentrations at the groundwater table. Significant concentration reductions due to dispersion occur only if the source concentrations decrease significantly prior to the arrival of the contaminant at the groundwater table. Biodegradation causes significant reduction of breakthrough concentrations only if flow velocities are low. 相似文献
204.
Kristen Kruger Woods Gordon W. Selling Peter H. Cooke 《Journal of Polymers and the Environment》2009,17(2):115-122
Blends of zein and polyvinylpyrrolidone (PVP) were compared based on their tensile properties, thermal properties and morphology.
Zein was blended with polyvinylpyrrolidone of varying molecular weights (10, 55, and 1,300 kDa) and films were cast from ethanol
solutions. Films cast using the higher molecular weight polymers showed an improvement in tensile strength, up to a 24% increase,
compared to control. Differential scanning calorimetry data for the blends showed single Tm and Tg values of an intermediate value between those of zein and PVP control samples. Field emission scanning electron microscopy
images show no obvious inhomogeneities, and confocal fluorescence microscopy showed no decreased uniformity in the PVP/zein
films compared to control. Electrospun fibers of the zein/PVP blends were also obtained. These findings suggest that zein
and polyvinylpyrrolidone combine to form a compatible blend, the first such blend of zein with a synthetic polymer. 相似文献
205.
Turnover potentially leads to a new individual being selected into a work team. This study investigated the safety-specific trust which team members place in their organisation’s selection and induction processes, and related this to the perceived risk from new employees. The research was conducted with teams working in forest harvesting, an occupation which has high-turnover, high risk and a high accident rate. Results indicate that trust in induction processes was negatively correlated with perceived risk from a new employee. Team members also engaged in a number of safety ensuring behaviours when a new individual joined the team, and these were related to the level of perceived risk, and how much they cared about their team members’ safety. It is argued that trust in the safety-specific characteristics of an organisation’s selection and induction process may have negative consequences for safety. 相似文献
206.
Peter M. Haas 《中国人口.资源与环境(英文版)》2017,15(3):186-188
<正>1.Introduction And now we have Parxit.On 1 June 2017,President Trump issued the highly unpopular announcement that the United States will withdraw from the 2015 Paris Agreement on Climate Change.In this brief piece,I will try to explain the reasons for this nearly unprecedented act of foreign policy folly(Ronald Reagan did pull out of the Law of the Sea 相似文献
207.
Jeffrey A. Sayer Chris Margules Agni K. Boedhihartono Terry Sunderland James D. Langston James Reed Rebecca Riggs Louise E. Buck Bruce M. Campbell Koen Kusters Chris Elliott Peter A. Minang Allan Dale Herry Purnomo James R. Stevenson Petrus Gunarso Agus Purnomo 《Sustainability Science》2017,12(3):465-476
Landscape approaches attempt to achieve balance amongst multiple goals over long time periods and to adapt to changing conditions. We review project reports and the literature on integrated landscape approaches, and found a lack of documented studies of their long-term effectiveness. The combination of multiple and potentially changing goals presents problems for the conventional measures of impact. We propose more critical use of theories of change and measures of process and progress to complement the conventional impact assessments. Theories of change make the links between project deliverables, outputs, outcomes, and impacts explicit, and allow a full exploration of the landscape context. Landscape approaches are long-term engagements, but short-term process metrics are needed to confirm that progress is being made in negotiation of goals, meaningful stakeholder engagement, existence of connections to policy processes, and effectiveness of governance. Long-term impact metrics are needed to assess progress on achieving landscapes that deliver multiple societal benefits, including conservation, production, and livelihood benefits. Generic criteria for process are proposed, but impact metrics will be highly situation specific and must be derived from an effective process and a credible theory of change. 相似文献
208.
Loran Christin Munteanu Catalina Verburg Peter H. Schmatz Dirk R. Bürgi Matthias Zimmermann Niklaus E. 《Regional Environmental Change》2017,17(8):2223-2235
Regional Environmental Change - The spatial distribution of forests in Europe represents the legacy of centuries of human land use decisions. Due to the limited availability of historical data,... 相似文献
209.
210.
The humanitarian common logistic operating picture: a solution to the inter‐agency coordination challenge
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Although significant progress has been made in developing the practice of humanitarian logistics, further improvements in efficiency and effectiveness have the potential to save lives and reduce suffering. This paper explores how the military/emergency services’ concept of a common operating picture (COP) can be adapted to the humanitarian logistics context, and analyses a practical and proven approach to addressing the key challenge of inter‐agency coordination and decision‐making. Successful adaptation could provide the mechanism through which predicted and actual demands, together with the location and status of material in transit, are captured, evaluated, and presented in real time as the basis for enhanced decision‐making between actors in the humanitarian supply network. Through the introduction of a humanitarian logistics COP and its linkages to national disaster management systems, local communities and countries affected by disasters and emergencies will be better placed to oversee and manage their response activities. 相似文献