Sustainable value assessment of farms using frontier efficiency benchmarks

Appropriate assessment of firm sustainability facilitates actor-driven processes towards sustainable development. The methodology in this paper builds further on two proven methodologies for the assessment of sustainability performance: it combines the sustainable value approach with frontier efficiency benchmarks. The sustainable value methodology tries to relate firm performance to the use of different resources. This approach assesses contributions to corporate sustainability by comparing firm resource productivity with the resource productivity of a benchmark, and this for all resources considered. The efficiency is calculated by estimating the production frontier indicating the maximum feasible production possibilities. In this research, the sustainable value approach is combined with efficiency analysis methods to benchmark sustainability assessment. In this way, the production theoretical underpinnings of efficiency analysis enrich the sustainable value approach. The methodology is presented using two different functional forms: the Cobb–Douglas and the translog functional forms. The simplicity of the Cobb–Douglas functional form as benchmark is very attractive but it lacks flexibility. The translog functional form is more flexible but has the disadvantage that it requires a lot of data to avoid estimation problems. Using frontier methods for deriving firm specific benchmarks has the advantage that the particular situation of each company is taken into account when assessing sustainability. Finally, we showed that the methodology can be used as an integrative sustainability assessment tool for policy measures.     

A Preliminary Study of Modeling the Air Pollution Effects fromTraffic Engineering Alternatives

Three separate mathematical models were combined to calculate the changes in carbon monoxide (CO) concentrations that might result from traffic engineering changes. The three models used were: (1) The Dynamic Highway Transportation model (DHTM) which relates traffic flow patterns to physical parameters and traffic signal characteristics of a network; (2) an emission model that predicts CO emissions from traffic flow parameters such as number of stops, idling time, etc; and (3) the APRAC-1A urban diffusion model which calculates CO concentrations from source distributions and meteorological factors. The composite model was applied to traffic in downtown Chicago for a specific set of meteorological conditions. Results are compared for two traffic signal control schemes. In those blocks where concentrations were highest, the model indicates a 20% reduction is possible through improved traffic signal controls. The model should be useful for testing other traffic control measures.     

The Need for a Pollution-FreeVehicle

The immediacy of the need for pollution-free vehicles is investigated by projecting to 2010 vehicle emission densities for eight urban areas and measures of population exposure to pollution for four cities. Three degrees of emission control are applied. Application of 50% control to 1968 automobiles maintains emission densities below present levels for the next 20 years, but is less effective in reducing population exposure to pollution, in some cases only slowing the rate of growth. Application of 50% control in 1968 and 80% in 1973 fails to reduce emission densities below 50% of the present. Reduction below 50% will eventually require an essentially pollution-free vehicle in many areas.     

Land Use,Geology, Enrichment,and Stream Biota in the Eastern Ridge and Valley Ecoregion: Implications for Nutrient Criteria Development1

Abstract: The eastern panhandle region of West Virginia is entirely within the Appalachian Ridge and Valley ecoregion. It is underlain by limestone in the eastern part and by shale and sandstone in the western part. Agricultural and urban development has affected the condition of the streams of this region. We examined samples from 165 stations in the Ridge and Valley, collected from 1998 to 2004. Land use, geological characteristics, physical and chemical parameters, and algal and macroinvertebrate assemblages were used to identify potential stressors that affect streams in the region. Our analyses indicated that both human land uses and ecoregional differences led to elevated nutrient concentrations in streams of the study areas. Multiple regression analyses indicated that both agricultural and urban land use in the watershed were associated with high nutrient concentrations (NO₂₊₃, total nitrogen, and total phosphorus) in streams. These elevated nutrient concentrations have led to increased algal biomass, increased trophic state, and degradation of macroinvertebrate community in the streams. Values of the West Virginia Stream Condition Index, as well as several other benthic macroinvertebrate metrics, decreased with increased nutrient concentrations and conductivity, especially in the limestone region. When regional differences were partitioned out in the analysis, nutrient concentrations became the strongest stressor in the limestone region while conductivity exhibited less of an effect on macroinvertebrate metrics. Meanwhile, periphyton diagnostic metrics also responded to increased nutrient concentrations, suggesting nutrients could be a cause of biological degradation in the Eastern Ridge and Valley region. Multiple approaches and multiple lines of evidence (reference approach and stressor‐response approach) were applied to develop nutrient benchmarks for different geological regions in the study watershed.     

Accident data for the Semantic Web

This paper describes concerns about the documentation, dissemination and use of lessons learned from mishap investigations, impediments posed by current practices, and opportunities for improvement. Lessons are presently developed, documented and stored primarily in narrative form and relational databases, and disseminated in many forms and media, including the Internet. Current practices pose many impediments to maximized development, dissemination and use. Investigation process research and new data concepts behind the Semantic Web, exploited elsewhere, offer potential opportunities to overcome these impediments. To exploit these opportunities, formation of a working group to develop an improved Semantic Web-friendly mishap investigation lessons learning system is proposed. An example illustrating an alternative approach is described to support a reasonable expectation that an alternative lessons learning system could be developed.     

Perspectives on secondary forest management in tropical humid lowland America

Secondary forests regrowing on abandoned agricultural land constitute an important, albeit widely overlooked, component in the landscape matrix of tropical lowland America. These 'new' forest resources on private land-holdings derive either from unsustainable cattle-ranching practices of better-off farmers or are part of the crop/fallow system of resource-poor farmers. If previous land use was light, secondary forest management may offer an interesting use option to better-off farmers, providing that subsidies for stand improvement are given. Improved fallow systems using partly the successional vegetation may be a way to establish sustainable small-scale agriculture for resource-poor farmers. Given some technical and financial input, land-use systems based on secondary vegetation could play a vital role both in sustainable landscape management and biodiversity conservation.