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931.
J. V. Bonta C. R. Amerman T. J. Harlukowicz W. A. Dick 《Journal of the American Water Resources Association》1997,33(4):907-917
ABSTRACT: A study was conducted to determine the effects of mining and reclaiming originally undisturbed watersheds on surface-water hydrology in three small experimental watersheds in Ohio. Approximately six years of data were collected at each site, with differing lengths of premining (Phase 1), mining and reclamation (Phase 2), and post-reclamation (Phase 3) periods. Mining and reclamation activities showed no consistent pattern iii base-flow, and caused slightly more frequent higher daily flow volumes. Phase 2 activities can cause reductions in seasonal variation in double mass curves compared with Phase 1. Restoration of seasonal variations was noticeably apparent at one site during Phase 3. The responses of the watersheds to rainfall intensities causing larger peak flow rates generally decreased due to mining and reclamation, but tended to exceed responses observed in Phase 1 during Phase 3. Natural Resources Conservation Service (NRCS) curve numbers increased due to mining and reclamation (Phase 2), ranging from 83 to 91. During Phase 3, curve numbers remained approximately constant from Phase 2, ranging from 87 to 91. 相似文献
932.
Quantitative Assessment of the Intertidal Environment of Kuwait I: Integrated Environmental Classification 总被引:1,自引:0,他引:1
Quantitative analysis of physical, chemical and biological data of the intertidal zone in Kuwait was undertaken to develop an integrated basis for assessing and protecting this sensitive coastal ecosystem. Cluster analyses were performed to determine the resemblance between the sampling stations based on the sediment composition, the benthic macrofauna and the physico-chemical characteristics of the intertidal sediment/water. Five distinct sub-environments were delineated within the intertidal zone of Kuwait. Each sub-environment was described in terms of number of taxa, mean density of organisms, sediment type, tidal level and dominant organisms. The physico-chemical parameters investigated were found to be unimportant in the distribution of the intertidal benthic macrofauna. On the other hand, sediment type was found to be a major factor in the overall composition of the benthic community. The benthic fauna and related characteristics of the sub-environments could be used as indicators to monitor changes in the intertidal ecosystem and as guides to protection and management of the different coasts. The approach described in this paper could also be adopted elsewhere to provide a sound basis for evaluating environmental impacts and for developing sustainable coastal management. 相似文献
933.
Until now no structured methodology existed for attuning environmental considerations to the business strategy of companies. The Environmental Competence Centre of Philips Sound & Vision in The Netherlands has developed and tested a methodology for this purpose. This methodology, called Selection of STRrategic Environmen Tal CHallenges (STRETCH), has proven to lead to promising results and should therefore be actively promoted. In this article, the authors show how the application of STRETCH provides the possibility of meeting three main objectives: First, focusing on the incorporation of environmental aspects into the company's business strategy can elicit innovations that may enhance the competitive position of the company by cost reduction and/or higher market shares. Second, the environmental opportunities and threats to be expected in the future can be anticipated in an earlier phase. Through this proactive approach a company can avoid external criticism and take the lead in environmental priority setting. Third, by applying the STRETCH methodology even higher eco-efficiencies are expected to be reached than through incremental, step-by-step environmental improvements. 相似文献
934.
Christopher I. Thornton Steven R. Abt Warren P. Clary 《Journal of the American Water Resources Association》1997,33(6):1279-1288
ABSTRACT: A meandering stream channel was simulated in the Hydraulics Laboratory at Colorado State University and a series of tests was conducted using four types of vegetation to evaluate the potential effects of vegetation on sediment deposition and retention in a stream channel. The data collected included average flow velocity, flow depth, length of vegetation, density of vegetation, cross-sectional area of the vegetative stem, wetted perimeter of the vegetative stem, and injection and flushing time. The findings indicated that the vegetation could retain from 30 to 70 percent of the deposited sediments. The ability of vegetation to entrap and retain sediment is related to the length and cross-sectional area of the vegetation. The variables describing the flow and the vegetative properties were combined to form a predictive parameter, the sedimentation factor (Sd) that can be compared with the amount of sediment entrapped by vegetation in a stream system. A relation was developed correlating vegetation length to sediment retention after flushing for flexibility and rigid vegetation. 相似文献
935.
Hugo A. Loaiciga Stephen Renehan 《Journal of the American Water Resources Association》1997,33(6):1313-1326
ABSTRACT: This paper synthesizes and interprets data pertaining to the evolution of average water revenue, water use, and the average cost of water supply in the City of Santa Barbara, California, from 1986 to 1996, a period which included one of the most devastating droughts in California this century. The 1987–1992 drought hit the study area particularly hard. The City of Santa Barbara was dependent exclusively on local sources for its water supply. That made it vulnerable as the regional climate is prone to extreme variability and recurrent droughts. The 1986–1992 drought provided a rare opportunity to assess the sensitivity of municipal water use to pricing, conservation, and other water management measures under extreme drought conditions. Our analysis indicates that the average cost of water rose more than three-fold in real terms from 1986 to 1996, while the gap between the average cost of supply and the average revenue per unit of water (= 100 cubic feet) rose in real terms from $0.14 in 1986 to $ 0.75 in 1996. The rise of $3.08 in the average cost of supplying one unit of water between 1986 and 1996 measures the cost of hedging drought risk in the study area. Water use dropped 46 percent at the height of the drought relative to pro-drought water use, and remains at 61 percent of the pre-drought level. The data derived from the 1987–1992 California drought are unique and valuable insofar as shedding light on drought/water demand adaptive interactions. The experience garnered on drought management during that unique period points to the possibilities available for future water management in the Arid West where dwindling water supplies and burgeoning populations are facts that we must deal with. 相似文献
936.
937.
Christopher A. Janicak 《Journal of Safety Research》1996,27(4):233-239
This study examined employers′ perceived knowledge of the Hazard Communication Standard (HCS) requirements prior to the inspection in which they were cited for an HCS violation. A lack of staff available to implement the HCS program was identified as having a significant impact upon compliance (p < 01). The perceived difficulty with compliance was also examined by the violations received by the organization. Those organizations cited for failing to have a written program identified a lack of staff available to implement the HCS requirements as having a greater impact upon compliance than those not cited for written program violations (p < 05). Suggested methods for improving the overall compliance with the HCS may include using the many compliance resources available through insurance companies, safety organizations, and state programs. Areas for further research include identifying the availability, use, and effectiveness of the outside safety and health compliance resources. 相似文献
938.
939.
More than 1500 manufactured gas plant (MGP) sites exist throughout the U.S. Many are contaminated with coal tar from coal-fueled gas works which produced ‘town gas’ from the mid-1800s through the 1950s.1,2 Virtually all old U.S. cities have such sites. Most are in downtown areas as they were installed for central distribution of manufactured gas. While a few sites are CERCLA/Superfund, most are not. However, the contaminants and methods used for remediation are similar to those used for Superfund clean-ups of coal tar contamination from wood-treating and coke oven facilities. Clean-up of sites is triggered by regulatory pressure, property transfers and re-development as well as releases to the environment — in particular, via groundwater migration. Due to utility de-regulation, site clean-ups may also be triggered by sale of a utility or of a specific utility site to other utilities. Utilities have used two approaches in dealing with their MGP sites. The first is ‘do nothing and hope for the best’. History suggests that, sooner or later, these sites become a bigger problem via a release, citizen lawsuit or regulatory/public service commission intervention. The second, far better approach is to define the problem now and make plans for waste treatment or immobilization. This paper describes recent experience with a high capacity/low cost thermal desorption process for this waste and reviews non-thermal technology, such as bio-treatment, capping, recycling, and dig and haul. Cost data is provided for all technologies, and a case study for thermal treatment is also presented. 相似文献
940.
Ernest J. Kulik Joseph P. Lingle Thomas A. Nowlan Rickie G. Nesbit 《补救:环境净化治理成本、技术与工艺杂志》1996,6(4):51-66
For both private corporations and military branches, downsizing and consolidation are becoming more commonplace. A range of environmental concerns must be addressed to effectively implement a consolidation program. A facility deactivation program can often become a minefield for an organization. Responsible personnel are typically inexperienced with the process, and this can lead to costly mistakes. This article provides insight into this topic based on experience gained with a multifacility program and related environmental issues. It emphasizes the importance of detailed, up-front, proactive project planning; a solid program management system; and accurate identification of project objectives and deliverables. 相似文献