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851.
Jerad D. Bales Benjamin F Pope 《Journal of the American Water Resources Association》2001,37(1):91-104
ABSTRACT: A set of procedures for identifying changes in selected streamflow characteristics at sites having long‐term continuous streamflow records is illustrated by using streamflow data from the Waccamaw River at Freeland, North Carolina for the 55‐year period of 1940–1994. Data were evaluated and compared to streamflow in the adjacent Lumber River Basin to determine if changes in streamflow characteristics in the Waccamaw River were localized and possibly the result of some human activity, or consistent with regional variations. Following 1963, droughts in the Waccamaw Basin seem to have been less severe than in the Lumber Basin, and the annual one‐, seven‐, and 30‐day low flows exhibited a slightly increasing trend in the Waccamaw River. Mean daily flows in the Waccamaw River at the 90 percent exceedance level (low flows) during 1985–194, a relatively dry period, were very nearly equal to flows at the same exceedance level for 1970–1979, which represents the 10‐year period between 1940 and 1994 with the highest flows. Prior to the 1980s, flows per unit drainage area in the Waccamaw Basin were generally less than those in the Lumber Basin, but after 1980, the opposite was true. The ratio of base flow to runoff in the Waccamaw River may have changed relative to that in the Lumber River in the late 1970s. There was greater variability in Waccamaw River streamflow than in Lumber River flow, and flow variability in the Waccamaw River may have increased slightly during 1985–1994. 相似文献
852.
853.
Jacob J. Oleson Naresh Kumar Brian J. Smith 《Environmental and Ecological Statistics》2013,20(2):297-314
Many advancements have been introduced to tackle spatial and temporal structures in data. When the spatial and/or temporal domains are relatively large, assumptions must be made to account for the sheer size of the data. The large data size, coupled with realities that come with observational data, make it difficult for all of these assumptions to be met. In particular, air quality data are very sparse across geographic space and time, due to a limited air pollution monitoring network. These “missing” values make it difficult to incorporate most dimension reduction techniques developed for high-dimensional spatiotemporal data. This article examines aerosol optical depth (AOD), an indirect measure of radiative forcing, and air quality. The spatiotemporal distribution of AOD can be influenced by both natural (e.g., meteorological conditions) and anthropogenic factors (e.g., emission from industries and transport). After accounting for natural factors influencing AOD, we examine the spatiotemporal relationship in the remaining human influenced portion of AOD. The presented data cover a portion of India surrounding New Delhi from 2000–2006. The proposed method is demonstrated showing how it can handle the large spatiotemporal structure containing so much missing data for both meteorologic conditions and AOD over time and space. 相似文献
854.
Morten Ryhl-Svendsen Geo Clausen Zohir Chowdhury Kirk R. Smith 《Atmospheric environment (Oxford, England : 1994)》2010,44(6):735-744
Carbon monoxide (CO) and particulate matter (PM2.5) were measured in two reconstructed Danish farmhouses (17–19th century) during two weeks of summer. During the first week intensive measurements were performed while test cooking fires were burned, during the second week the houses were monitored while occupied by guest families. A masonry hearth was located in the middle of each house for open cooking fires and with heating stoves. One house had a chimney leading to the outside over the hearth; in the other, a brickwork hood led the smoke into an attic and through holes in the roof. During the first week the concentration of PM2.5 averaged daily between 138 and 1650 μg m?3 inside the hearths and 21–160 μg m?3 in adjacent living rooms. CO averaged daily between 0.21 and 1.9 ppm in living areas, and up to 12 ppm in the hearths. Highest concentrations were measured when two fires were lit at the same time, which would cause high personal exposure for someone working in the kitchens. 15 min averages of up to 25 400 μg m?3 (PM2.5) and 260 ppm CO were recorded. WHO air quality guidelines were occasionally exceeded for CO and constantly for PM2.5. However, air exchange and air distribution measurements revealed a large draw in the chimney, which ensured a fast removal of wood smoke from the hearth area. The guest families were in average exposed to no more than 0.21 ppm CO during 48 h. Based on a hypothetical time-activity pattern, however, a woman living in this type of house during the 17–19th century would be exposed to daily averages of 1.1 ppm CO and 196 μg m?3 PM2.5, which exceeds WHO guideline for PM2.5, and is comparable to what is today observed for women in rural areas of developing countries. 相似文献
855.
Douglas W. Smith 《Conservation biology》2005,19(5):1676-1678
856.
Abstract The Foliar Washoff of Pesticides (FWOP) Model was developed to provide an empirical simulation of pesticide washoff from plant leaf surfaces as influenced by rainfall amount. To evaluate the technique, simulations by the FWOP Model were compared to those by the foliar washoff algorithm of the Chemical, Runoff and Erosion from Agricultural Management Systems (CREAMS) Model. The two algorithms were linked individually to the Pesticide Runoff Simulator (PRS) for the comparison. Five years of test data from a Mississippi watershed were used to evaluate six insecticides (carbaryl, profenofos, methyl parathion, permethrin, phorate, and toxaphene). Initially, the FWOP model was used to evaluate the relative impact of chemical distribution (foliage versus soil) on the subsequent foliar washoff and soil surface contributions to runoff losses. Results indicated that runoff losses were low If all of the insecticide was applied to the foliage whereas high losses occurred if applied only to the soil. When an assumed application was distributed between the plant and soil (i.e., 90% to foliage and 10% to soil), predicted runoff losses compared well with observed field data (<3% of the application rate). Except for toxaphene, the FWOP model generally predicted less washoff and subsequent runoff losses than the CREAMS approach. Simulated toxaphene washoff losses were in good agreement with observed field data. Statistical comparisons of the two modeling approaches using the Kolmogorov‐Smirnov test showed differences in the two cumulative frequency distributions for washoff but smaller differences for runoff. Average 5‐year runoff losses, however, were greater using the CREAMS approach—by factors of 2, 3, and 3 for profenofos, methyl parathion and phorate, respectively. Results from this study will be useful for upgrading current exposure assessment models to more accurately address foliar washoff losses of pesticides as well as for assessing the impact of foliar‐applied chemicals on environmental quality. 相似文献
857.
Institutional credibility and leadership: critical challenges for community-based natural resource governance in rural and remote Australia 总被引:1,自引:1,他引:0
Community-based natural resource management (CBNRM) institutions are challenged with finding common ground as a basis for
action among diverse resource users and stakeholders. Establishing and maintaining institutional credibility within their
regions, catchments, communities and among their membership is fundamental to overcoming the challenge. So too is applying
appropriate institutional and governance structures and appointing appropriate leaders. Drawing on triangulated case study
data collected over a 12-month period using multiple methods, this paper examines the influence of institutional credibility
and leadership on the functioning, decision-making and governance of two CBNRM institutions in Queensland, Australia. The
paper shows that stakeholders have very different expectations of what makes a CBNRM institution credible. Satisfying the
multiple expectations requires CBNRM institutions to incorporate diverse stakeholder representation, assert their legitimacy
and demonstrate accountability, transparency, fairness and justice. The paper also draws attention to the value and importance
of appointing inspirational leaders who focus on encouraging followers to pursue collective goals. Comparing the merits and
constraints of appointing average Joes versus community elites to the Boards of CBNRM institutions, the paper highlights the
urgent need for community-based natural resource governance and inspirational leadership education and training programs to
improve the availability and quality of CBNRM leadership in rural Australia. Since combining credible CBNRM institutions with
inspirational leaders does not necessarily equate to sustainable on-ground NRM outcomes, it is critical that the education
and training programs emphasise the importance of monitoring and evaluating the improvements in decision-making processes
and in decision outcomes. 相似文献
858.
A. M. Smith J. H. Struck 《Journal of the Air & Waste Management Association (1995)》2013,63(5):251-258
The purpose of this study was to gather air quality data for four pollutants inside and outside of three pairs of structures for different seasons of the year. This paper presents results obtained during the summer, fall, and winter seasons of 1969–70. Suspended particulate, soiling particulate, carbon monoxide, and sulfur dioxide were measured at pairs of public buildings, office buildings, and private homes. A brief preliminary program was conducted during the winter of 1969 to verify our procedures and equipment and to assess the effects of heating and cooking systems in private homes on indoor levels of air pollutants. Two self-contained and portable instrument packages were constructed for the measurement program. The major components of each trailer package were a central vacuum pump for drawing air samples through particulate collection niters, four paper-tape soiling samplers, a conductimetric analyzer for sulfur dioxide, an infrared analyzer for carbon monoxide, a master control unit, and supporting apparatus to make the trailer self-contained. Each pair of buildings was sampled simultaneously for a two-week period. Four sampling points were selected at each structure, two outside and two inside. Suspended particulate samples were collected for 12-hr day and night periods, soiling particulate samples for 2-hr periods, and gaseous samples for 5-min periods. The results show the ease of penetration of particulate into private homes and the removal ability of air conditioning systems. Outdoor daily activity greatly influences particulate levels and urban carbon monoxide levels. Internal generation of pollutants was a significant factor in measured interior concentrations in some of the structures sampled. 相似文献
859.
Corinna Nunneri Hermann J. Lenhart Benjamin Burkhard Wilhelm Windhorst 《Regional Environmental Change》2008,8(1):31-43
Offshore wind power generation represents a chance to supply energy in a more sustainable way; however, the ecological risks
associated with the construction and operation of offshore wind farms are still largely unknown. This paper uses the concept
of ecological risk for analysing ecological changes during construction of offshore wind farms. “Ecological risk” is defined
as the potentially reduced ability of providing ecosystem services. The ERSEM ecosystem model allows assessing ecological
risk based on a number of selected variables (integrity indicators) and under the assumption that increased suspended matter
concentration during construction of wind farms affects ecosystem functioning. We conclude that ecological risk is adequate
to describe the effects of wind farm constructions, although the computation procedure still needs to be refined and the choice
of indicators further optimised. In this context, the choice of indicators available in modelling as well as in monitoring
time-series may offer the way forward. 相似文献
860.
Pascale Carayon François Sainfort Michael J. Smith 《International journal of occupational safety and ergonomics》2013,19(2):303-334
AbstractIn this paper, we present a macroergonomic model of work design that is applied and tested to examine Total Quality Management (TQM) in the public sector. According to the model, TQM can influence different aspects of work design and quality of working life (QWL), Questionnaire data collected in 2 public sector organizations in the USA show that TQM can have both positive and negative impact on work design and QWL. The main positive impact of TQM was found on job content, job control and participation, and social relationships. The main negative impact of TQM was on workload, uncertainty, and clarity of job duties. The impact of TQM on QWL was mixed. Our results show that the impact of TQM on work design and QWL varied very much across the 6 participating departments, as well as within the departments. Further research is warranted to assess the human impact of TQM, in particular research on the linkage between various aspects of TQM, on one hand, and work design and QWL, on the other hand. 相似文献