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Urban stream restoration continues to be used as an ecological management tool, despite uncertainty about the long‐term sustainability and resilience of restored systems. Evaluations of restoration success often focus on specific instream indicators, with limited attention to the wider basin or parallel hydrologic and geomorphic process. A comprehensive understanding of urban stream restoration progress is particularly important for comparisons with nonurban sites as urban streams can provide substantial secondary benefits to urban residents. Here, we utilize a wide range of indicators to retrospectively examine the restoration of Nine Mile Run, a multi‐million dollar stream restoration project in eastern Pittsburgh (Pennsylvania, USA). Examination of available continuous hydrological data illustrates the high cost of failures to incorporate the data into planning and adaptive management. For example, persistent extreme flows drive geomorphic degradation threatening to reverse hydrologic connections created by the restoration and impact the improved instream biotic communities. In addition, human activities associated with restoration efforts suggest a positive feedback as the stream restoration has focused effort on the basin beyond the reach. Ultimately, urban stream restoration remains a potentially useful management tool, but continued improvements in post‐project assessment should include examination of a wider range of indicators.  相似文献   
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Few studies exist on how chloride from chloride‐based deicers is transported in infiltration‐based stormwater control measures. In 2009, the U.S. Environmental Protection Agency (USEPA) constructed a 0.4 ha parking lot in Edison, New Jersey, that was surfaced with permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA). Each surface type has four equally sized, lined sections that direct all infiltrate to separate 5.7 m3 collection tanks. The USEPA acute criterion for aquatic life (860 mg/l) was exceeded in events immediately following a snow event. Concentrations of the infiltrate exceeded the detection limit (5 mg/l) year round but did not exceed the USEPA chronic toxicity (230 mg/l) after April. The chloride concentration decreased with cumulative rainfall since previous snow event, and a power regression described this relationship. In the power regression, the coefficient (b) described the initial concentration following a snow event, and the exponent (m) described the rate in which chloride was flushed through the system with infiltrating water. PC had the largest coefficient (5,664) and largest absolute exponent (?0.92), followed closely by PICP (= 4,943 and = ?0.87), and distantly by PA (= 2,907 and = ?0.67). The differences in release rate were proportional to the measured surface infiltration rates of 4,000; 2,400; and 200 cm/h for PC, PICP, and PA, respectively. These results will assist those who manage or regulate stormwater where receiving waters are chloride impaired.  相似文献   
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Lisa Dorn  Brian Brown   《Safety Science》2003,41(10):837-859
This paper reports a qualitative study of 54 police drivers who were interviewed about their views on police driver training, driving strategies and their accident involvement. Study of the transcribed interviews indicated that officers constructed narratives of themselves as being highly aware of hazards presented by other road users and they used a variety of discursive devices to minimise their own culpability and attribute risk elsewhere. Rather than maintaining a straightforward ‘illusion of invulnerability’ they were formulating a ‘topography of risk’ in which they were responding to hazards presented by suspects or other road users. Their meticulously detailed accounts of the circumstances surrounding accidents serve to place them as knowledgeable and impartial participants and create a sense of expertise and authority. Training initiatives could profitably seek to challenge this ‘topography of risk’ and sense of authority so that drivers more fully appreciate the hazard they may present to themselves and the public.  相似文献   
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A sample of 135 female human service professionals completed the Maslach Burnout Inventory (MBI) and the Staff Burnout Scale for Health Professionals (SBS), along with measures of job satisfaction, role stress, self-esteem, alienation, and locus of control. Principal components factor analysis of this battery indicates considerable covariation of self-reported burnout with job dissatisfaction and perceived role stress, and moderate overlap with more general feelings of alienation and low self-esteem. Item factor analysis of the 22 MBI items resulted in two independent factors, one defined by the Emotional Exhaustion and Depersonalization items, the other by the Personal Accomplishment items. Item factoring of the SBS produced one large factor which was highly correlated with the MBI exhaustion-depersonalization factor. Implications of these findings for the construct validity of the MBI and SBS are discussed.  相似文献   
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A 17-year monitoring programme of reef flats at Ko Phuket, Thailand afforded an opportunity to evaluate both univariate and multivariate measures of environmental stress in an assessment of change on coral reef ecosystems. The sites at Ko Phuket suffered the effects of dredging in 1986-1987 and then anomalously low sea levels in 1997-1998 as a result of climate-related events in the Indian Ocean. Univariate measures of species diversity and taxonomic distinctness ((*) increased across the reef flat, reflecting the greater effects of physical stresses on the inner reef flats (compared with outer reef flats) at all sites, with more congeneric species present on the inner reef and more confamilial species on the outer reef. Multivariate measures showed a clear breakdown in seriation patterns at all sites during the dredging in 1987 and in 1998, as a result of earlier negative sea-level anomalies. Recovery from environmental disturbances was obvious within 12 months in each case. The domination of the reefs by massive coral species, which are physiologically adapted to intertidal living and which display partial rather than total colony mortality, may be a factor contributing to the apparent resilience of the reef flats together with continued recruitment and survival of juvenile corals during adverse environmental conditions. Elevated sea temperatures and extensive bleaching of corals in 1991, 1995, and 1998 had no effect upon coral community measures, with many corals recovering their zooxanthellae numbers within 3-5 months of the bleaching events.  相似文献   
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The U.S. Environmental Protection Agency (EPA) performed a reservoir diagnosis and developed low-cost recommendations to improve drinking water quality for the city of Nizhnii Tagil, Russia. Despite widespread regional pollution, water quality within the drinking water supply source can be summarized as generally good. Sampling and analysis efforts did not reveal appreciable amounts of hazardous chemicals or metals. The major water quality problem stems from an abundance of blue-green algae during the summer months, causing drinking water taste and odor problems and filter clogging at the water treatment plant. City water treatment officials also frequently experience difficulties with maintaining an effective disinfection residual in the distribution system because it spans more than 30 kilometers in length. Regrowth of microorganisms in the distribution system often causes coliform bacteria counts to exceed standards. The implementation of a watershed protection and management program, and the installation of a new disinfection system, to purify drinking water and to reduce bacterial growth in the distribution system should improve drinking water quality for the city residents.  相似文献   
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