RUNOFF PREDICTION USING REMOTE SENSING IMAGERY1

ABSTRACT: Percent imperviousness is an important parameter in modeling the urban rainfall-runoff process and is usually determined using manual methods such as random sampling or conventional accounting methods. In this study two computerized methods are used for estimating the percent imperviousness of urban watersheds using high altitude remote sensing imagery. These methods include the Laser Image Processing Scanner and the Video-Tape Camera system. Imperviousness is directly estimated in the former method while in the latter it is estimated as a function of the statistics of the responses on emulsions of the imagery. The percent imperviousness computed by utilizing remote sensing imagery was used with the conceptual models of rainfall-runoff models. The models were applied to four urban watersheds and the runoff prediction results indicate that imperviousness determined by using remote sensing imagery was as accurate as that obtained by the manual methods, and that the use of remote sensing imagery requires significantly less time and money.     

The predictive validity of safety climate

PROBLEM: Safety professionals have increasingly turned their attention to social science for insight into the causation of industrial accidents. One social construct, safety climate, has been examined by several researchers [Cooper, M. D., & Phillips, R. A. (2004). Exploratory analysis of the safety climate and safety behavior relationship. Journal of Safety Research, 35(5), 497-512; Gillen, M., Baltz, D., Gassel, M., Kirsch, L., & Vacarro, D. (2002). Perceived safety climate, job Demands, and coworker support among union and nonunion injured construction workers. Journal of Safety Research, 33(1), 33-51; Neal, A., & Griffin, M. A. (2002). Safety climate and safety behaviour. Australian Journal of Management, 27, 66-76; Zohar, D. (2000). A group-level model of safety climate: Testing the effect of group climate on microaccidents in manufacturing jobs. Journal of Applied Psychology, 85(4), 587-596; Zohar, D., & Luria, G. (2005). A multilevel model of safety climate: Cross-level relationships between organization and group-level climates. Journal of Applied Psychology, 90(4), 616-628] who have documented its importance as a factor explaining the variation of safety-related outcomes (e.g., behavior, accidents). Researchers have developed instruments for measuring safety climate and have established some degree of psychometric reliability and validity. The problem, however, is that predictive validity has not been firmly established, which reduces the credibility of safety climate as a meaningful social construct. The research described in this article addresses this problem and provides additional support for safety climate as a viable construct and as a predictive indicator of safety-related outcomes. METHODS: This study used 292 employees at three locations of a heavy manufacturing organization to complete the 16 item Zohar Safety Climate Questionnaire (ZSCQ) [Zohar, D., & Luria, G. (2005). A multilevel model of safety climate: Cross-level relationships between organization and group-level climates. Journal of Applied Psychology, 90(4), 616-628]. In addition, safety behavior and accident experience data were collected for 5 months following the survey and were statistically analyzed (structural equation modeling, confirmatory factor analysis, exploratory factor analysis, etc.) to identify correlations, associations, internal consistency, and factorial structures. RESULTS: Results revealed that the ZSCQ: (a) was psychometrically reliable and valid, (b) served as an effective predictor of safety-related outcomes (behavior and accident experience), and (c) could be trimmed to an 11 item survey with little loss of explanatory power. IMPACT ON INDUSTRY: Practitioners and researchers can use the ZSCQ with reasonable certainty of the questionnaire's reliability and validity. This provides a solid foundation for the development of meaningful organizational interventions and/or continued research into social factors affecting industrial accident experience.     

Downscaling and visioning of mountain snow packs and other climate change implications in North Vancouver, British Columbia

This paper provides an overview of a collaborative study on visualizing climate change at the local scale. A conceptual framework has been developed, in which local scenarios and visualizations of climate change impacts and response were created to facilitate local dialogue on incorporating climate change into long-term planning and implementation of community development decisions. As part of a larger effort to generate a new integrated participatory visioning process, this paper describes a case study of the District of North Vancouver which created visualizations of changing mountain snow and landscape conditions, and provides new insights on issues and dilemmas in using realistic landscape visualizations to depict scientific modelling projections, local responses to climate change, and uncertainty. Results from this study suggest that the visualizations, and subsequent dialogue sessions, did influence emotional response to climate change as well as self-assessed understanding of adaptation and mitigation response options. However, there is a need to test this visioning process with larger heterogeneous groups of participants in order to better assess its effectiveness in enabling dialogue on local responses to climate change.     

Factors affecting TCLP lead leachability from computer CPUs

The factors impacting lead leachability from computer central processing units (CPUs) during the toxicity characteristic leaching procedure (TCLP) were investigated. Several CPUs were disassembled and their component materials were decreased in size to meet the requirements of the TCLP. The impact of CPU composition was examined by leaching different combinations of the CPU components. The ferrous metal content of the mixture greatly impacted lead leaching. TCLP lead concentrations of CPUs predicted by leaching the lead-bearing printed wire boards alone were much greater than those measured when the ferrous metal of the CPU was included in the mixture. The leaching of iron and zinc from the galvanized steel components of the CPU created electrochemical conditions where lead was less soluble. Additional size reduction beyond that required by the TCLP did not result in additional lead leaching. As the volume of head space above the leaching solution increased, the concentration of lead measured increased as well.     

Identifying Differences Between Off-Highway Vehicle (OHV) and Non-OHV User Groups for Recreation Resource Planning

Off-highway vehicle (OHV) riding is among the fastest growing recreational activities in the United States. However, little research exists about the central components of outcomes-focused management (OFM) as it relates to motorized recreation. Utilizing a two-activity dichotomy, OHV and non-OHV centric user groups were compared on several key concepts associated with OFM, including desired experiences, perceived and desired recreation opportunity spectrum-type settings, and intentional behaviors (i.e., place-protective behavior, spending-time intentions) toward potential changes in settings. Results indicated that the two groups were different in terms of intensity and relative rankings of their perceived experiences and settings. Although both groups preferred social bonding, stress relief, nostalgia and learning experiences, the OHV user group ranked using equipment and achieving physical fitness experiences as more important than the non-OHV group. The non-OHV user group preferred enjoying nature and solitude/tranquility experiences more strongly than the OHV user group. Further analysis found that both groups perceived settings that they recreated in to be pristine and preferred such conditions, and both groups preferred moderate levels of rules and regulations. Finally, the OHV user group was more reactive to rules and regulations, while the non-OHV user group expressed stronger intentions to protect the environmental quality of recreation areas. The results suggest that planners and managers who understand OHV user's perceptions and behaviors could provide enhanced recreation opportunities potentially providing additional beneficial outcomes for motorized and non-motorized groups in spatially different zones. Additional implications for planners and managers and future studies are discussed.     

Statistical inference on patch-specific survival and movement rates from marked animals

Empirical estimates of patch-specific survival and movement rates are needed to parametrize spatially explicit population models, and for inference on the effects of habitat quality and fragmentation on populations. Data from radio-marked animals, in which both the fates and habitat locations of animals are known over time, can be used in conjunction with continuous-time proportional hazards models to obtain inferences on survival rates. Discrete-time conditional logistic models may provide inference on both survival and movement rates. We use Monte Carlo simulation to investigate accuracy of estimates of survival from both approaches, and movement rates from conditional logistic regression, for two habitats. Bias was low (relative bias < 0.04) and interval coverage accurate (close to the nominal 0.95) for estimates of habitat effect on survival based on proportional hazards. Bias was high ( relative bias 0.60) and interval coverage poor ( = 0.26 vs. nominal 0.95) for estimates of habitat effect based on conditional logistic regression; bias was especially influenced by heterogeneity in survival and the shape of the hazard function, whereas both bias and coverage were affected by ‘memory’ effects in movement patterns. Bias estimates of movement rate was low ( relative bias < 0.05), but interval coverage was poor ( = 0.48–0.80), possibly as a result of poor performance of a Taylor series estimate of variance. An example is provided from a radio-telemetry study of 47 wintering American woodcock (Scolopax minor), illustrating practical difficulties in field studies to parametrize these models. We also discuss extensions of continuous-time models to explicitly include a movement process, and further examine tradeoffs between continuous and discrete models.     

Stream buffer effectiveness in an agriculturally influenced area, southwestern Georgia: responses of water quality, macroinvertebrates, and amphibians

To determine useful metrics for assessing stream water quality in the Southeastern Coastal Plain, we examined differences among two buffered and three unbuffered streams in an agricultural landscape in southwestern Georgia. Potential indicators included amphibian diversity and abundance, aquatic macroinvertebrate populations, riparian vegetative structure, water quality, and stream physical parameters. Variability among sites and treatments (buffered vs. unbuffered) existed, with sites in the same treatment as most similar, and disturbances from a nearby eroding gully strongly affecting one unbuffered site. Of the invertebrate metrics examined, percentages of clingers, Ephemeroptera-Plecoptera-Trichoptera (EPT), Elmidae (Coleoptera), Crustacea (Decapoda and Amphipoda), and dipterans were found to be possible indicators of stream health for perennial streams within this region. Overall, buffered sites showed higher percentages of sensitive invertebrate groups and showed lower and more stable concentrations of nitrate N, suspended solids, and fecal coliforms (FCs). Percent canopy cover was similar among sites; however, riparian vegetative coverage and percent leaf litter were greatest at buffered sites. No differences in amphibian abundance, presence, and absence within the riparian area were apparent between sites; however, instream larval salamanders were more abundant at buffered streams. In this study, stream buffers appeared to decrease nutrient and sediment loads to adjacent streams, enhancing overall water quality. Selected benthic macroinvertebrate metrics and amphibian abundance also appeared sensitive to agricultural influences. Amphibians show potential as indicator candidates, however further information is needed on their responses and tolerances to disturbances from the microhabitat to landscape levels.     

Renewables as a pathway to environmental sustainability targets in the era of trade liberalization: empirical evidence from Turkey and the Caspian countries

Environmental Science and Pollution Research - The quest for improved environmental quality through low-carbon emission has been explored in this study in the wake of the growing call for a...     

Predicting the Performance of VOC Condensers

Volatile organic compounds (VOC) are commonly released from process vents and equipment leaks. These discharges are a threat to the environment, and cost manufacturers millions of dollars in added raw material costs. For these reasons, one may be confronted with the task of evaluating alternatives for reducing VOC emissions from a process plant.

There are two basic approaches for reducing VOC emissions: a) changing the process, or b) installing control equipment.

Methods for changing the process include replacing highly volatile solvents with less volatile ones, making piping changes to reduce the number of vents, tightening the process to eliminate open tanks and leaks, altering process temperature and pressure conditions, etc. Equipment that is applicable to VOC emission control includes incineration, carbon adsorption, scrubbing and condensation.

This article addresses the application of condensers to process vents. A computer spreadsheet model is described, providing a quick screening which indicates whether a vent condenser might be a viable option for controlling emissions. The template provides, for each of a range of condensing temperatures, estimates for the amount of VOC that will be condensed, the condenser size and the tons of refrigeration required.