3 resultados para Leading indicators of safety performance
em Digital Commons - Michigan Tech
Resumo:
Advances in information technology and global data availability have opened the door for assessments of sustainable development at a truly macro scale. It is now fairly easy to conduct a study of sustainability using the entire planet as the unit of analysis; this is precisely what this work set out to accomplish. The study began by examining some of the best known composite indicator frameworks developed to measure sustainability at the country level today. Most of these were found to value human development factors and a clean local environment, but to gravely overlook consumption of (remote) resources in relation to nature’s capacity to renew them, a basic requirement for a sustainable state. Thus, a new measuring standard is proposed, based on the Global Sustainability Quadrant approach. In a two‐dimensional plot of nations’ Human Development Index (HDI) vs. their Ecological Footprint (EF) per capita, the Sustainability Quadrant is defined by the area where both dimensions satisfy the minimum conditions of sustainable development: an HDI score above 0.8 (considered ‘high’ human development), and an EF below the fair Earth‐share of 2.063 global hectares per person. After developing methods to identify those countries that are closest to the Quadrant in the present‐day and, most importantly, those that are moving towards it over time, the study tackled the question: what indicators of performance set these countries apart? To answer this, an analysis of raw data, covering a wide array of environmental, social, economic, and governance performance metrics, was undertaken. The analysis used country rank lists for each individual metric and compared them, using the Pearson Product Moment Correlation function, to the rank lists generated by the proximity/movement relative to the Quadrant measuring methods. The analysis yielded a list of metrics which are, with a high degree of statistical significance, associated with proximity to – and movement towards – the Quadrant; most notably: Favorable for sustainable development: use of contraception, high life expectancy, high literacy rate, and urbanization. Unfavorable for sustainable development: high GDP per capita, high language diversity, high energy consumption, and high meat consumption. A momentary gain, but a burden in the long‐run: high carbon footprint and debt. These results could serve as a solid stepping stone for the development of more reliable composite index frameworks for assessing countries’ sustainability.
Resumo:
Multiple indices of biotic integrity and biological condition gradient models have been developed and validated to assess ecological integrity in the Laurentian Great Lakes Region. With multiple groups such as Tribal, Federal, and State agencies as well as scientists and local watershed management or river-focused volunteer groups collecting data for bioassessment it is important that we determine the comparability of data and the effectiveness of indices applied to these data for assessment of natural systems. We evaluated the applicability of macroinvertebrate and fish community indices for assessing site integrity. Site quality (i.e., habitat condition) could be classified differently depending on which index was applied. This highlights the need to better understand the metrics driving index variation as well as reference conditions for effective communication and use of indices of biotic integrity in the Upper Midwest. We found the macroinvertebrate benthic community index for the Northern Lakes and Forests Ecoregion and a coldwater fish index of biotic integrity for the Upper Midwest were most appropriate for use in the Big Manistee River watershed based on replicate sampling, ability to track trends over time and overall performance. We evaluated three sites where improper road stream crossings (culverts) were improved by replacing them with modern full-span structures using the most appropriate fish and macroinvertebrate IBIs. We used a before-after-control-impact paired series analytical design and found mixed results, with evidence of improvement in biotic integrity based on macroinvertebrate indices at some of the sites while most sites indicated no response in index score. Culvert replacements are often developed based on the potential, or the perception, that they will restore ecological integrity. As restoration practitioners, researchers and managers, we need to be transparent in our goals and objectives and monitor for those results specifically. The results of this research serve as an important model for the broader field of ecosystem restoration and support the argument that while biotic communities can respond to actions undertaken with the goal of overall restoration, practitioners should be realistic in their expectations and claims of predicted benefit, and then effectively evaluate the true impacts of the restoration activities.
Resumo:
Moisture induced distresses have been the prevalent distress type affecting the deterioration of both asphalt and concrete pavement sections. While various surface techniques have been employed over the years to minimize the ingress of moisture into the pavement structural sections, subsurface drainage components like open-graded base courses remain the best alternative in minimizing the time the pavement structural sections are exposed to saturated conditions. This research therefore focuses on assessing the performance and cost-effectiveness of pavement sections containing both treated and untreated open-graded aggregate base materials. Three common roadway aggregates comprising of two virgin aggregates and one recycled aggregate were investigated using four open-ended gradations and two binder types. Laboratory tests were conducted to determine the hydraulic, mechanical and durability characteristics of treated and untreated open-graded mixes made from these three aggregate types. Results of the experimental program show that for the same gradation and mix design types, limestone samples have the greatest drainage capacity, stability to traffic loads and resistance to degradation from environmental conditions like freeze-thaw. However, depending on the gradation and mix design used, all three aggregate types namely limestone, natural gravel and recycled concrete can meet the minimum coefficient of hydraulic conductivity required for good drainage in most pavements. Tests results for both asphalt and cement treated open-graded samples indicate that a percent air void content within the range of 15-25 will produce a treated open-graded base course with sufficient drainage capacity and also long term stability under both traffic and environmental loads. Using the new Mechanistic and Empirical Design Guide software, computer simulations of pavement performance were conducted on pavement sections containing these open-graded base aggregate base materials to determine how the MEPDG predicted pavement performance is sensitive to drainage. Using three truck traffic levels and four climatic regions, results of the computer simulations indicate that the predicted performance was not sensitive to the drainage characteristics of the open-graded base course. Based on the result of the MEPDG predicted pavement performance, the cost-effectiveness of the pavement sections with open-graded base was computed on the assumption that the increase service life experienced by these sections was attributed to the positive effects of subsurface drainage. The two cost analyses used gave two contrasting results with the one indicating that the inclusion of open-graded base courses can lead to substantial savings.