排序方式: 共有38条查询结果,搜索用时 15 毫秒
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Warren A. Gebert William R. Krug 《Journal of the American Water Resources Association》1996,32(4):733-744
ABSTRACT: Trends in streamflow characteristics were analyzed for streams in southwestern Wisconsin's Driftless Area by using data at selected gaging stations. The analyses indicate that annual low flows have increased significantly, whereas annual flood peaks have decreased. The same trends were not observed for forested areas of northern Wisconsin. Streamflow trends for other streams in southeastern Wisconsin draining predominantly agricultural land were similar to trends for Driftless Area streams for annual low flows. The causes for the trends are not well understood nor are the effects. Trends in annual precipitation do not explain the observed trends in streamflow. Other studies have found that erosion rates decreased significantly in the Driftless Area, and have attributed this reduction to a change of agricultural practices, which increase infiltration, decrease flood peaks, and increase low flows. 相似文献
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Núria Roura-Pascual David M. Richardson R. Arthur Chapman Tanja Hichert Rainer M. Krug 《Regional Environmental Change》2011,11(2):311-320
Invasive species alter the functioning of natural ecosystems, creating “novel ecosystems” comprising species occurring in
combinations with no analogs within a given biome. This poses major challenges for managers who cannot rely exclusively on
previous experiences. Multiple factors that drive invasion and which interact in complex ways demand innovative management
approaches. We show the utility of scenario planning in considering options for management in a region with substantial problems
with invasive alien plants: South Africa’s Cape Floristic Region. The approach allows us to identify the driving forces that
shape the status and trajectories of major woody invasive plants and to identify sensible strategies by considering a set
of scenarios based on the main uncertainties that encapsulate the linkages between the various components of the management
of biological invasions. Attitudes of landowners and management capacity are shown to be the crucial uncertainties influencing
the spread of major invasive species; axes based on these factors define our scenarios. Mapping current management projects
onto scenario axes highlighted key differences among areas. These insights can assist in directing particular management units
toward more desirable futures. Our study highlights the need to link social, political and legal constraints with ecological
processes to assure the effectiveness of management operations in controlling biological invasions. 相似文献
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Bernd Nowack Nicole C Mueller Harald F Krug Peter Wick 《Environmental Sciences Europe》2014,26(1):1-10
Major accident regulations aim at protecting the population and the environment from possible accidental releases of chemicals. To achieve this goal, the regulations need to be reassessed in light of the development of new technologies. A currently rapidly growing new technology is nanotechnology, and engineered nanomaterials (ENM) are already produced and used in commercial products. The aim of this work was therefore to evaluate the current knowledge on human and ecotoxicology of ENM and their release and behavior in the environment in the context of major accident prevention. Nano-specific release paths are not to be expected. The established safety standards in the chemical industry are also applicable to ENM, especially the separate storage of flammable solvents and detention reservoirs. The potential of a release to the environment of ENM in powder form is larger than for suspensions; however, it can be minimized by safety measures established for conventional dusts. The considered human toxicology studies show that to date not conclusive enough answers regarding the toxicity of ENM can be made. The effects are dependent not only on the material itself but more on the functionalization, surface reactivity, size, and form. The acute ecotoxicity of ENM seems to be similar to the one of the corresponding microparticles (TiO2) or the respective dissolved ions (Ag, Zn) with the exception of photocatalytically active nano-TiO2, which has an increased toxicity. In order to guarantee that all ENM are included in the existing major accident regulations, different classification options are possible and the advantages and disadvantages are discussed. An important step will be the compulsory inclusion of nano-specific data in the Material Safety Data Sheets that serve as the basic medium to transfer information from the manufacturer to downstream users and authorities. We also call for a regular monitoring of the production and uses for ‘high production volume ENM’ that could have the largest implications for major accident regulations. 相似文献
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Byung Kyu Kim Jamie Krams Erin Krug Mark Leaseburge Justin Lemley Ammar Alkhawaldeh Ray A. Mentzer M. Sam Mannan 《Journal of Loss Prevention in the Process Industries》2012,25(5):780-787
Several catastrophic events in the process industry have caused extensive damage to life and property and have forever changed the process safety landscape. Despite the commitment from the industry, incidents still occur with similar root causes, impacting major companies in various ways. This work examines the financial impact of such incidents on the stability and future of affected companies in different industries. Several devastating incidents were analyzed to evaluate the direct impact in the short- and long-term and to discuss factors influencing the ability of affected companies to withstand the consequence of catastrophic events. 相似文献
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Suzanne O' Hara Thomas Krug Jacqueline Quinn Christian Clausen Cherie Geiger 《补救:环境净化治理成本、技术与工艺杂志》2006,16(2):35-56
Emulsified zero‐valent iron (EZVI) is a surfactant‐stabilized, biodegradable emulsion that forms droplets consisting of a liquid‐oil membrane surrounding zero‐valent iron (ZVI) particles in water. This article summarizes the results obtained during the first field‐scale deployment of EZVI at NASA's Launch Complex 34 (LC34) located on Cape Canaveral Air Force Station, Florida, in August 2002 and presents the results of recent follow‐on laboratory tests evaluating the mechanisms, which contribute to the performance of the technology. The field‐scale demonstration evaluated the performance of EZVI containing nanoscale zero‐valent iron (NZVI) when applied to dense, nonaqueous phase liquid (DNAPL) trichloroethylene (TCE) in the saturated zone. Results of the field demonstration indicate substantial reductions in TCE soil concentrations (greater than 80 percent) at all but two soil boring locations and significant reductions in TCE groundwater concentrations (e.g., 60 percent to 100 percent) at all depths targeted with EZVI. Laboratory tests conducted in 2005 suggest that both NZVI particles and EZVI containing NZVI can provide significant reductions in TCE mass when used to treat TCE DNAPL in small test reactors. However, EZVI was able to reduce TCE concentrations to lower levels than were obtained with NZVI alone, likely as a result of the combined impact of sequestration of the TCE into the oil phase and degradation of the TCE with the NZVI. © 2006 Wiley Periodicals, Inc. 相似文献
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