Pollution Control Policies and Natural Resource Dynamics: A Theoretical Analysis

Policies for the management of natural resources and the resources themselves interact to form complex systems. In this paper, we present a highly simplified model that can be used to study the general features of those systems. The model has three state variables, the abundance of the resource, environmental pollution, and the capital devoted to pollution control. We analyse it graphically using the singular perturbation approach. Two modes of behavior are possible; stationary and cyclic. When the abundance of the resources varies cyclically, the length of the period of resource scarcity depends on population size, economic activity, pollution per unit of output, and policy constraints. We distinguish between two classes of policies, one in which decision-makers base their investments in pollution control capital on the abundance of the resource, and another in which those decisions depend on the amount of pollution. We show that policies based on the observation of pollution are safer than those based on resource abundance, because in the latter case, small changes in policy variables can lead much more easily to a collapse of the resource. Increases in population size, even when accompanied by an equiproportional increase in the pollution control budget can lead to a change from stationary to cyclic behavior, especially where policies are based on resource abundance.     

Multicriteria Decision Aid in Supporting Decisions Related to Groundwater Protection

In the recent decades, there have been frequent conflicts between groundwater resources and environmentally hazardous activities. An example is the construction of the new highway through the important glaciofluvial esker aquifer Nybroåsen, which passes the protection zone of the water supply for the Kalmar municipality, in the southeastern part of Sweden. The decision to build the new road through this important aquifer has been strongly questioned by the municipality and the public because the value of the water resources in Nybroåsen was not taken into consideration during the first phase of the decision-making process. Multicriteria decision aid (MCDA) is applied as a tool to structure and analyze the four road alternatives proposed in the environmental impact assessment for the above conflict. The alternatives, including the existing road, are in conflict with water resources, agriculture, natural, and cultural values. The impacts on the water resources have been predicted by a two-dimensional physically based time-variant flow and solute groundwater model, which has been calibrated and evaluated. The MCDA illustrates how it can be used to identify (1) actors and their concerns, (2) ranking of alternative road scenarios according to actors preferences, and (3) coalition groups of actors, i.e., groups that have similar views with regard to the road alternatives. The analysis shows that the two best compromise solutions obtained in the MCDA were unacceptable by the strongest coalition group, showing that either the family of criteria was not well chosen or new alternatives should have been developed.     

A technology for the treatment of olive-mill waste water in a continuously fed plant

A bench-scale pilot plant has been developed for the treatment of olive-mill water. The plant is fed in a continuous mode and implements a primary treatment (sand filtering and irradiation with UV-rays) and a secondary treatment (anoxic and aerobic biological treatment). Satisfactory results were obtained and the treated green water falls under the limits of the Italian legislation. Veratric and ferulic acid biodegradation were studied under anoxic conditions in order to verify the requirements for optimal biodegradation. Electronic Publication     

ELEVATED ATMOSPHERIC CO2 INCREASES WATER AVAILABILITY IN A WATER-LIMITED GRASSLAND ECOSYSTEM1

ABSTRACT: Californian annual grassland on sandstone (moderately fertile) and serpentine (very infertile) soils at the Jasper Ridge Biological Preserve, Stanford, California, were exposed to ambient or elevated (ambient + 36 Pa CO₂) atmospheric CO₂ in open-top chambers since December 1991. We measured ecosystem evapotranspiration with open gas-exchange systems, and soil moisture with time-domain reflectometry (TDR) over 0–15 cm (serpentine) and 0–30 cm (sandstone) depths, at times of peak above ground physiological activity. Evapotranspiration decreased by 12 to 63 percent under elevated CO₂ in three consecutive years in the sandstone ecosystem (p = 0.053, p = 0.162, p = 0.082 in 1992, 1993, and 1994, respectively). In correspondence with decreased evapotranspiration, late-season soil moisture reserves in the sandstone were extended temporally by 10 ± 3 days in 1993 and by 28 ± 11 days in 1994. The effect of elevated CO₂ on soil moisture was greater in the drier spring of 1994 (419 mm annual rainfall) than in 1993 (905 mm annual rainfall). In the serpentine ecosystem, evapotranspiration and soil moisture reserves were not clearly affected by elevated CO₂. Soil water may be conserved in drought-affected ecosystems exposed to elevated CO₂, but the amount of conservation appears to depend on the relative importance of transpiration and soil evaporation in controlling water flux.     

River pollution from non-point sources: a new simplified method of assessment

Assessment of the pollution of water bodies from non-point sources is a complex data- and time-consuming task. The potential non-point pollution index (PNPI), is a new tool designed to assess the global pressure exerted on rivers and other surface water bodies by different land uses. The main feature of PNPI is the wide availability of its input data. Very detailed input maps, often lacking over many areas, are not needed for PNPI calculation. As a consequence of the input data used, the modelling of physical reality and of processes is heavily simplified. The authors counterbalanced such a simplification using an 'expert system' approach. The system bypasses the accurate representation of the physical reality to assess globally the pollution potential of different land uses according to the judgement of scientists. The scientific community proposes many models for depicting the dynamics of pollutants coming from diffuse sources. Most of them can be grouped into two broad categories: statistical models and physically based models. PNPI belongs to neither of the above-mentioned groups. PNPI is a GIS-based, watershed-scale tool designed to inform decision makers and public opinion about the potential environmental impacts of different land management scenarios. PNPI applies the multicriteria technique to pollutant dynamics and water quality. The pressure exerted on water bodies by diffuse pollution coming from land units is expressed as a function of three indicators: land use, run-off and distance from the river network. They are calculated from land use data, geological maps and a digital elevation model (DEM). The weights given to different land uses and to the three indicators were set according to experts' evaluations and allow calculation of the value of the PNPI for each node of a grid representing the watershed; the higher the PNPI of the cell, the greater the potential impact on the river network. The output of the calculation is presented in the form of maps that highlight areas that are more likely to produce pollution. Last, possibilities, strategies and results of the validation of the PNPI are described. In the authors' view, the explicit link between land use and potential pollution on which PNPI is based, together with its high communication potential, make it particularly interesting for a participatory and integrated approach to land management and environmental protection.     

Soil erosion under different vegetation covers in the Venezuelan Andes

This comparative study of soil erosion considered different environments in an ecological unit of the Venezuelan Andes. The soils belong to an association of typic palehumults and humic dystrudepts. Soil losses were quantified by using erosion plots in areas covered by four types of vegetation, including both natural and cultivated environments. The highest soil erosion rate evaluated corresponded to horticultural crops in rotation: reaching a value of 22 Mg ha^–1 per year. For apple tree (Malus sylvestris Miller) plots, soil losses reached values of 1.96 Mg ha^–1 per year. Losses from pasture (Pennisetum clandestinum Hochst. ex Chiov.) plots, without livestock grazing, were as high as 1.11 Mg ha^–1 during the second year of the experiment. The highest soil losses generated from plots under natural forest were equal to 0.54 Mg ha^–1 per year. Environmental factors such as total and effective rainfall, runoff, and some soil characteristics as those related to soil losses by water erosion were evaluated. The type of management applied to each site under different land use type and the absence of conservation practices explain, to a large extent, the erosive processes and mechanisms.     

Interactive effects of personality and organizational politics on contextual performance

The authors explored the process of evaluating contextual performance in the context of a politically charged atmosphere. They hypothesized that the negative relationship between perceptions of organizational politics and contextual performance is weaker among workers high in three of the Big Five model of personality dimensions—agreeableness, extraversion, and conscientiousness. Data were collected from a matched sample of 540 supervisors and subordinates employed in the private sector. Results indicated that the interaction of politics and the personality dimension of agreeableness explained a significant incremental amount of variance in the interpersonal facilitation facet of contextual performance. These findings demonstrate the need to consider both the situation and the person as antecedents of contextual performance. Copyright © 2002 John Wiley & Sons, Ltd.     

Persistent organic pollutants in Alaskan ringed seal (Phoca hispida) and walrus (Odobenus rosmarus) blubber

Since 1987, the Alaska Marine Mammal Tissue Archival Project (AMMTAP) has collected tissues from 18 marine mammal species. Specimens are archived in the National Institute of Standards and Technology's National Biomonitoring Specimen Bank (NIST-NBSB). AMMTAP has collected blubber, liver and/or kidney specimens from a number of ringed seals (Phoca hispida) from the areas near Nome and Barrow, Alaska and walruses (Odobenus rosmarus) from several locations in the Bering Sea. Thirty-three ringed seal and 15 walrus blubber samples from the NIST-NBSB were analyzed for persistent organic pollutants (POPs). The compounds determined included PCBs (28 congeners or congener groups), DDT and related compounds, hexachlorobenzene (HCB), hexachlorocyclohexane isomers (HCHs), chlordanes, dieldrin, and mirex. POP concentrations in ringed seal blubber were significantly higher in Barrow than in Nome when statistically accounting for the interaction of age and gender; HCB, however, was not statistically different between the two locations. Unlike males, POP concentrations and age were not significantly correlated in females probably as a result of lactational loss. POP concentrations in walrus blubber were lower than in ringed seal blubber for SigmaPCBs, chlordanes, and HCHs, but higher for dieldrin and mirex. POP concentrations in ringed seals and walrus from Alaska provide further evidence that the western Arctic tends to have lower or similar POP concentrations compared to the eastern Canadian Arctic.     

Geophysical and hydrological data assimilation to monitor water content dynamics in the rocky unsaturated zone

In recent years, geophysics is increasingly used to study the flow and transport processes in the vadose zone. Particularly, when the vadose zone is made up of rocks, it is difficult to install sensors in the subsurface to measure hydrological state variables directly. In these cases, the electrical resistivity tomography (ERT) represents a useful tool to monitor the hydrodynamics of the infiltration and to estimate hydraulic parameters and state variables, such as hydraulic conductivity and water content. We propose an integrated approach aimed at predicting water content dynamics in calcarenite, a sedimentary carbonatic porous rock. The uncoupled hydrogeophysical approach proposed consists in 4D ERT monitoring conducted during an infiltrometer test under falling head conditions. Capacitance probes were installed to measure water content at different depths to validate the estimations derived from ERT. A numerical procedure, based on a data assimilation technique, was accomplished by combining the model (i.e., Richards’ equation) with the observations in order to provide reliable water content estimations. We have used a new data assimilation method that is easy to implement, based on the ensemble Kalman filter coupled with Brownian bridges. This approach is particularly suitable for strongly non-linear models, such as Richards’ equation, in order to take into account both the model uncertainty and the observation errors. The proposed data assimilation approach was tested for the first time on field data. A reasonable agreement was found between observations and predictions confirming the ability of the integrated approach to predict water content dynamics in the rocky subsoil.     

Case study: Risk prioritization and ISO 14001 at Acushnet rubber company

Increasingly, companies are striving to prioritize environmental management decisions based on risk and perceived impact. This case study on Acushnet Rubber begins a four‐part series profiling environmental decision making at leading companies. © 2000 John Wiley & Sons, Inc.