COMPARATIVE EVALUATION OF LAND COVER DATA SOURCES FOR EROSION PREDICTION1

ABSTRACT: A fundamental problem in protecting surface drinking water supplies is the identification of sites highly susceptible to soil erosion and other forms of nonpoint source (NPS) pollution. The New York City Department of Environmental Protection is trying to identify erodible sites as part of a program aimed at avoiding costly filtration. New York City's 2,000 square mile watershed system is well suited for analysis with geographic information systems (GIS); an increasingly important tool to determine the spatial distribution of sensitive NPS pollution areas. This study used a GIS to compare three land cover sources for input into the Modified Universal Soil Loss Equation (MUSLE), a model estimating soil loss from rangeland and forests, for a tributary watershed within New York City's water supply system. Sources included both conventional data (aerial photography) and Landsat data (MSS and TM images). Although land cover classifications varied significantly across these sources, location-specific and aggregate watershed predictions of the MUSLE were very similar. We conclude that using Landsat TM imagery with a hybrid classification algorithm provides a rapid, objective means of developing large area land cover databases for use in the MUSLE, thus presenting an attractive alternative to photo interpretation.     

REVIEW OF DETERMINATION OF INSTREAM FLOW REQUIREMENTS WITH SPECIAL APPLICATION TO AUSTRALIA1

ABSTRACT: A critical examination of the techniques used to assess and specify environmental instream flow requirements is provided. The strengths and weaknesses of individual techniques are evaluated on both an absolute and a comparative basis. Particular attention is given to the problem of specifying environmental flow requirements in Australia where the hydrology has distinctly different characteristics to those in countries where most of the models for prediction of instream flow requirements were developed. Broad recommendations as to the suitability and use of the different techniques for different conditions are provided.     

Petroleum biodegradation in soil: The effect of direct application of surfactants

The direct application of surfactants to petroleum-contaminated soil has been proposed as a mechanism to increase the bioavailability of insoluble compounds. Solubilization of hydrophobic compounds into the aqueous phase appears to be a significant rate limiting factor in petroleum biodegradation in soil. Nonionic surfactants have been developed to solubilize a variety of compounds, thus increasing the desorption of contaminants from the soil. In this study, laboratory scale land treatment scenarios were used to monitor the bioremediation of petroleum contaminated soils. In efforts to achieve the lowest levels of residual petroleum hydrocarbons in the soil following biotreatment, 0.5 and 1.0% (volume/weight) surfactant was blended into soils under treatment. Two soil types were studied, a high clay content soil and a sandy, silty soil. In both cases, the addition of surfactant (Adsee 799®, a blend of ethoxylated fatty acids, Witco Corporation) stimulated biological activity as indicated by increased heterotropbic colony forming units per gram of soil. However, the increased activity was not correlated with removal of petroleum hydrocarbons. The results suggest that the application of surfactants directly to the soil for the purpose of solubilizing hydropbobic compounds was not successful in achieving greater levels of petroleum hydrocarbon removal.     

Toward an Understanding of Norm Prevalence: A Comparative Analysis of 20 Years of Research

/ Norms are defined as evaluative standards regarding individual behavior or conditions in a given context. They define what behavior should be, rather than actual behavior. Norm prevalence refers to the proportion of individuals in a population who can articulate a norm in a given evaluation context. This paper empirically examines the prevalence of encounter norms in 56 evaluation contexts. Data for this comparative analysis were obtained from 30 studies that used a single-item question asking recreationists to indicate the highest number of encounters they would tolerate before the experience changed. Four predictor variables were examined: (1) type of resource, (2) type of activity, (3) type of encounter, and (4) question response format. As anticipated, norm prevalence varied by type of resource (backcountry or frontcountry), type of encounter (no conflict versus conflict), and question response format (two-category implicit, two-category explicit, and three-category). These three independent variables explained 64% of the variance in norm prevalence. Also as hypothesized, there was no relationship between type of activity (consumptive or nonconsumptive) and norm prevalence. Implications for future research and management are discussed; it is argued that prevalence is an important characteristic of social norms.     

A review of chemical ecology in poison frogs

Herein we review what is known about the chemical ecology of poison frogs with a focus on dendrobatid poison frogs. While five anuran families are known to have an alkaloid-derived chemical defense, the dendrobatids have been studied in greatest detail and provides chemical ecologists with a complex model system for understanding how chemical defenses operate in real time and may have evolved through evolutionary time. We describe the diversity of alkaloid defenses known from frogs, alkaloid sequestration, biosynthesis and modification, and we review what is known concerning arthropod sources for alkaloids. There is variation in nearly every attribute of the system and we try to describe some of the challenges associated with unraveling the complexities of this model system.     

Workplace and Environmental Air Contaminant Concentrations Measured by Open Path Fourier Transform Infrared Spectroscopy: A Statistical Process Control Technique to Detect Changes from Normal Operating Conditions

Open path Fourier transform infrared (OP-FTIR) spectroscopy is a new air monitoring technique that can be used to measure concentrations of air contaminants in real or near-real time. OP-FTIR spectroscopy has been used to monitor workplace gas and vapor exposures, emissions from hazardous waste sites, and to track emissions along fence lines. This paper discusses a statistical process control technique that can be used with air monitoring data collected with an OP-FTIR spectrometer to detect departures from normal operating conditions in the workplace or along a fence line. Time series data, produced by plotting consecutive air sample concentrations in time, were analyzed. Autocorrelation in the time series data was removed by fitting dynamic models. Control charts were used with the residuals of the model fit data to determine if departures from defined normal operating conditions could be rapidly detected. Shewhart and exponentially weighted moving average (EWMA) control charts were evaluated for use with data collected under different room air flow and mixing conditions.

Under rapidly changing conditions the Shewhart control chart was able to detect a leak in a simulated process area. The EWMA control chart was found to be more sensitive to drifts and slowly changing concentrations in air monitoring data. The time series and statistical process control techniques were also applied to data obtained during a field study at a chemical plant. A production area of an acrylonitrile, 1,3-butadiene, and styrene (ABS) polymer process was monitored in near-real time. Decision logics based on the time series and statistical process control technique introduced suggest several applications in workplace and environmental monitoring. These applications might include signaling of an alarm or warning, increasing levels of worker respiratory protection, or evacuation of a community, when gas and vapor concentrations are determined to be out-of-control.     

Persistent organochlorine pollutants and menstrual cycle characteristics

An evolving body of evidence suggests an adverse relation between persistent organochlorine pollutants (POPs) and menstruation, though prospective longitudinal measurement of menses is limited and served as the impetus for study. We prospectively assessed the relation between a mixture of persistent organochlorine compounds and menstrual cycle length and duration of bleeding in a cohort of women attempting to become pregnant. Eighty-three (83%) women contributing 447 cycles for analysis provided a blood specimen for the quantification of 76 polychlorinated biphenyls and seven organochlorine pesticides, and completed daily diaries on menstruation until a human chorionic gonadotropin confirmed pregnancy or 12 menstrual cycles without conception. Gas chromatography with electron capture detection was used to quantify concentrations (ng g⁻¹ serum); enzymatic methods were used to quantify serum lipids (mg dL⁻¹). A linear regression model with a mixture distribution was used to identify chemicals grouped by purported biologic activity that significantly affected menstrual cycle length and duration of bleeding adjusting for age at menarche and enrollment, body mass index, and cigarette smoking.A significant 3-d increase in cycle length was observed for women in the highest tertile of estrogenic PCB congeners relative to the lowest tertile (β = 3.20; 95% CI 0.36, 6.04). A significant reduction in bleeding (<1 d) was observed among women in the highest versus lowest tertile of aromatic fungicide exposure (γ = −0.15; 95% CI −0.29, −0.00). Select POPs were associated with changes in menstruation underscoring the importance of assessing chemical mixtures for female fecundity.     

Operationalising just sustainability: towards a model for place-based governance

As the concept of sustainability broadens to include social aspects, sustainability organisations must embrace strategies that allow them to more effectively address community issues and procedural concerns. Biosphere reserves (BRs) and model forests (MFs) advocate strongly for community engagement to achieve place-based sustainability; in practice, however, these organisations have had variable success in effectively engaging community residents and addressing their needs and interests. In this paper, we offer a framework for place-based governance for sustainability that is used to compare strategies used in BRs and MFs operating in the Maritime Provinces of Canada with the operations of Vibrant Communities, an anti-poverty organisation that operates locally in Saint John, New Brunswick. We draw attention to three imperatives: comprehensive understanding, community empowerment, and community-based outcomes, and five procedural drivers: local leadership, strong networks, diverse community engagement, learning together, and information sharing. Based on our results, we provide greater clarity on processes that address the imperatives and mobilise the drivers of effective place-based governance for sustainability. Our results suggest that there is a need for theory and practice to advance beyond current understandings of sustainability governance to enhance the capacity of organisations seeking to implement community-based sustainability strategies.     

Revealing inadvertent elitism in stakeholder models of environmental governance: assessing procedural justice in sustainability organizations

Consensus-based multi-stakeholder forms of environmental governance involving government, private and civil society actors, have become popular for advancing sustainability, but have been criticized for failing to achieve procedural justice objectives including recognition, participation and strengthening capabilities. Yet, how such models have functioned within non-governmental organizations dedicated to advancing sustainability has been underexplored. This paper assesses the procedural elements of consensus-based multi-stakeholder models used within Canadian biosphere reserves and model forests, two organizations working to address environment and sustainability issues. We draw on strategic documents and semi-structured interviews from five organizations in Canada to analyze their governance structures and processes against a framework for procedural justice. We find the organizational structure reproduces elitism and professionalism associated with stakeholder models more generally and reproduces challenges associated with recognition, participation and building capabilities found in other stakeholder approaches. Meeting broader sustainability challenges requires organizations to address procedural justice issues in addition to their traditional environmental concerns.     

What’s counted as a reindeer herder? Gender and the adaptive capacity of Sami reindeer herding communities in Sweden

Researchers of adaptive capacity and sustainable livelihoods have frequently used social, cultural, human, economic and institutional capitals to better understand how rural and resource-dependent communities address environmental, social and economic stresses. Yet few studies have considered how men and women contribute differently to these capitals to support community resilience overall. Our research sought to understand the differential contributions of Sami men and women to the adaptive capacity of reindeer husbandry and reindeer herding communities in northern Sweden. Our focus revealed a gendered division of labour in reindeer herding as an economic enterprise as well as gendered contributions to a broader conceptualization of reindeer husbandry as a family and community-based practice, and as a livelihood and cultural tradition. Based on our results, we recommend that community resilience be enhanced by generating more opportunities for men to achieve higher levels of human and economic capital (particularly outside of herding activities) and encouraging women to contribute more directly to institutional capital by participating in the formation and implementation of legislation, policies and plans.