The reliability of experts' opinions in constructing a composite environmental index: The case of ESI 2005

The complexity of the environment demands a well-constructed composite environmental index (CEI) to provide a useful tool to draw attention to environmental conditions and trends for policy purposes. Among the common difficulties in constructing a proper CEI are uncertainties due to the selection of the most representative underlying variables or indicators. A degree of uncertainty accompanies experts' judgments, and to deal with vague, subjective or inconsistent information, logic other than classic is required. This study analyzes a procedure that uses different experts' opinions in constructing a CEI, with the use of paraconsistent annotated logic. For this, a sensitivity analysis of the Environmental Sustainability Index (ESI 2005) was used as an example to assess the reliability of experts' opinions. The uncertainty due to the disagreement in experts' opinions clearly indicates that the forms we presently use to measure and monitor the actual environment are insufficient, that is, there is a lack of a “science of sustainability”.     

Predicting land cover using GIS, Bayesian and evolutionary algorithm methods

Modelling land cover change from existing land cover maps is a vital requirement for anyone wishing to understand how the landscape may change in the future. In order to test any land cover change model, existing data must be used. However, often it is not known which data should be applied to the problem, or whether relationships exist within and between complex datasets. Here we have developed and tested a model that applied evolutionary processes to Bayesian networks. The model was developed and tested on a dataset containing land cover information and environmental data, in order to show that decisions about which datasets should be used could be made automatically. Bayesian networks are amenable to evolutionary methods as they can be easily described using a binary string to which crossover and mutation operations can be applied. The method, developed to allow comparison with standard Bayesian network development software, was proved capable of carrying out a rapid and effective search of the space of possible networks in order to find an optimal or near-optimal solution for the selection of datasets that have causal links with one another. Comparison of land cover mapping in the North-East of Scotland was made with a commercial Bayesian software package, with the evolutionary method being shown to provide greater flexibility in its ability to adapt to incorporate/utilise available evidence/knowledge and develop effective and accurate network structures, at the cost of requiring additional computer programming skills. The dataset used to develop the models included GIS-based data taken from the Land Cover for Scotland 1988 (LCS88), Land Capability for Forestry (LCF), Land Capability for Agriculture (LCA), the soil map of Scotland and additional climatic variables.     

Landfill site selection using spatial information technologies and AHP: A case study in Beijing,China

Site selection is an important and necessary issue for waste management in fast-growing regions. Because of the complexity of waste management systems, the selection of the appropriate solid waste landfill site requires consideration of multiple alternative solutions and evaluation criteria. Based on actual conditions of the study area, we considered economic factors, calculated criteria weights using the analytical hierarchy process (AHP), and built a hierarchy model for solving the solid waste landfill site-selection problem in Beijing, China. A geographic information system (GIS) was used to manipulate and present spatial data. All maps are graded from 1 (lowest suitability) to 5 (highest suitability) using spatial information technologies. The candidate sites were determined by aggregation based on the criteria weights. The candidate sites are divided by ‘best’, ‘good’ and ‘unsuitable’ landfill areas. Best landfill areas represent optimal sites; good landfill areas can be used as back-up candidate sites. Our work offers a siting methodology and provides essential support for decision-makers in the assessment of waste management problems in Beijing and other rapidly developing cities in developing countries.     

Changes in negative air ions concentration under different light intensities and development of a model to relate light intensity to directional change

The purpose of this research was to determine changes in negative air ion (NAI) concentrations produced by plants grown under different light intensities. NAI concentrations were observed and analyzed in an outdoor green space with five plant species (Aloe arborescens, Clivia miniata, Chlorophytum comosum, Opuntia brunnescens, Crassula portulacea) and A. arborescens was then grown under controlled-light conditions in an enclosed space for the subsequent light intensity experiment.     

Use of Descriptors of Ecosystem Functioning for Monitoring a National Park Network: A Remote Sensing Approach

Baseline assessments and monitoring of protected areas are essential for making management decisions, evaluating the effectiveness of management practices, and tracking the effects of global changes. For these purposes, the analysis of functional attributes of ecosystems (i.e., different aspects of the exchange of matter and energy) has advantages over the traditional use of structural attributes, like a quicker response to disturbances and the fact that they are easily monitored through remote sensing. In this study, we described the spatiotemporal patterns of different aspects of the ecosystem functioning of the Spanish national parks and their response to environmental changes between 1982 and 2006. To do so, we used the NOAA/AVHRR-GIMMS dataset of the Normalized Difference Vegetation Index (NDVI), a linear estimator of the fraction of photosynthetic active radiation intercepted by vegetation, which is the main control of carbon gains. Nearly all parks have significantly changed during the last 25 years: The radiation interception has increased, the contrast between the growing and nongrowing seasons has diminished, and the dates of maximum and minimum interception have advanced. Some parks concentrated more changes than others and the degree of change varied depending on their different environmental conditions, management, and conservation histories. Our approach identified reference conditions and temporal changes for different aspects of ecosystem functioning, which can be used for management purposes of protected areas in response to global changes.     

Convergence or divergence in desertification risk? Scale-based assessment and policy implications in a Mediterranean country

This paper explores changes (1990–2000) in two environmental indexes with the aim of providing empirical evidence on regional and local convergence in an increasing-impact phenomenon such as Land Degradation (LD) in Italy. Convergence analysis for ESAI (Environmental Sensitive Area Index) and LVI (Land Vulnerability Index) was developed at five different geographical scales. Results indicate that territorial disparities in land vulnerability tend to increase during the investigated period following a defined spatial pattern that depends on land quality, the environmental context and the economic performance of regional systems. Finally, the implications this process has on policy strategies aimed at mitigating desertification risk are discussed.     

Costs and benefits of improving wild salmon passage in a regulated river

This paper presents a cost-benefit analysis (CBA) of a trade-off between salmon and hydropower production in the Ume/Vindel River, northern Sweden. A distinctive element of this analysis is that estimated changes in resource conditions are based on detailed river-specific data. A salmon population model was used to develop the scenario and a novel willingness to pay (WTP) question, which caters for uncertainty in a different manner, provided an interval estimate. Non-use values are the major contributors to the benefit (96–517 millions of Swedish kronor (MSEK)) of increasing the stock of wild salmon. Sensitivity analysis suggests that the opportunity costs in terms of lost electricity are typically higher than the estimated benefits.     

Octanol–air partition coefficients of polybrominated biphenyls

The octanol–air partition coefficients (K_OA) for PBB15, PBB26, PBB31, PBB49, PBB103 and PBB153 were determined as a function of temperature using a gas chromatographic retention time technique with 1,1,1-trichloro-2,2-bis (4-chlorophenyl) ethane (p,p′-DDT) as a reference substance. The internal energies of phase change from octanol to air (Δ_OAU) were calculated for the six compounds and were in the range from 74 to 116 kJ mol⁻¹. Simple regression equations of log K_OA versus relative retention times (RRTs) on gas chromatography (GC), and log K_OA versus molecular connectivity indexes (MCI) were obtained, for which the correlation coefficients (r²) were greater than 0.985 at 283.15 K and 298.15 K. Thus the K_OA values of the remaining PBBs can be predicted by using their RRTs and MCI according to these relationships.     

Biosorption of nickel(II) from aqueous solution by Aspergillus niger: Response surface methodology and isotherm study

In the present study, the effects of biosorbent Aspergillus niger dosage, initial solution pH and initial Ni(II) concentration on the uptake of Ni(II) by NaOH pretreated biomass of A. niger from aqueous solution were investigated. Batch experiments were carried out in order to model and optimize the biosorption process. The influence of three parameters on the uptake of Ni(II) was described using a response surface methodology (RSM) as well as Langmuir and Freundlich isotherm models. Optimum Ni(II) uptake of 4.82 mg Ni(II) g⁻¹ biomass (70.30%) was achieved at pH 6.25, biomass dosage of 2.98 g L⁻¹ and initial Ni(II) concentration of 30.00 mg L⁻¹ Ni(II). Langmuir and Freundlich were able to describe the biosorption isotherm fairly well. However, prediction of Ni(II) biosorption using Langmuir and Freundlich isotherms was relatively poor in comparison with RSM approaches. The biosorption mechanism was also investigated by using Fourier transfer infrared (FT-IR) analysis of untreated, NaOH pretreated, and Ni(II) loaded A. niger biomass.     

Effects of 2,4-dichlorophenoxyacetic acid formulation on medulla spinalis of Poecilia reticulata: A histopathological study

This study investigated the possible effects of a commonly used foliar herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) formulation on medulla spinalis of lebistes. Fish were exposed to 2,4-D (15, 30, 45 mg L⁻¹), behavioral changes were monitored. Fish were fixed, histopathological examination was carried out on sections taken from the upper parts of the fish body. Histopathology showed increase in neuronal loss, swelling indicating formation of intracellular edema, vacuolization noticed as the formation of vacuoles within or adjacent to cells, deformation in the Nissl granules, pyknosis and gliosis in medulla spinalis. Behavioral changes were decreased general activity, grouping, shortness in breath, sudden rotations and jumping, loss of equilibrium and colour. In conclusion, this commercial formulation of 2,4-D is considerably neurotoxic to lebistes. Fish constitute the last link in the chain of the feeding cycle in aquatic eco-system, number of studies investigating acute and chronic neurotoxicity of various herbicides in fish should be increased.