The potential impacts of sea level rise along the coastal zone of Kanyakumari District in Tamilnadu,India

Climate change associated with sea level rise (SLR) is one of the major environmental concerns of today. This paper presents an assessment of the impacts of sea level rise on the coastal zone of Kanyakumari District in Tamilnadu, India. Digital Elevation Model (DEM) combined with overlay techniques in GIS are used in determining the inundation zones along the coastal region. The analysis evaluated the impact on coastal fishing villages, landuse, tourist spots and sensitive areas under threat. The vulnerability of the coastal areas in Kanyakumari to inundation was quantified, based on the projected sea level rise scenarios of 0.5 and 1 m. Our findings reveal that approximately 13 km² of the land area of Kanyakumari would be permanently inundated due to SLR. This would result in loss of land, alteration of the coastal zone and affects coastal ecosystem. From the study, the mitigation measures (engineering measures) and Coastal Zone Management practices that can be taken to protect human life and property from sea level rise are suggested.     

Evaluation of a fast response pressure solver for flow around an isolated cube

This work describes and evaluates a pressure solver that has been incorporated into a fast response three-dimensional building-resolving diagnostic wind modeling system. The solver computes the three-dimensional pressure field around buildings and on exterior walls in terms of a coefficient of pressure by solving a simplified pressure Poisson equation (that neglects turbulence stresses in the Navier-Stokes) for incompressible flow. The input to the solver is the three-dimensional mean wind field obtained from a fast response empirical-diagnostic urban wind model. The present study is an evaluation of the pressure solver using wind-tunnel data for flow normal to and at a 45° angle to an isolated cubical building. Results for the normal incident wind angle case indicate that the model satisfactorily reproduces the general spatial patterns and the magnitude of the pressure difference around much of the cube. Details of the flow field that are not satisfactorily predicted include the spatial distribution of pressure on the roof and the lower half of the front side of the building and the magnitude along the sidewalls where pressures are over predicted. The results for the 45° case show reasonable agreement between the model and experiments on the front and the back walls, but over predict pressures on the leading edge of the rooftop. Regions with poor pressure predictions appear to be a result of unsatisfactory mean wind modeling.     

Empirical likelihood confidence intervals for adaptive cluster sampling

Adaptive cluster sampling (ACS) is an efficient sampling design for estimating parameters of rare and clustered populations. It is widely used in ecological research. The modified Hansen-Hurwitz (HH) and Horvitz-Thompson (HT) estimators based on small samples under ACS have often highly skewed distributions. In such situations, confidence intervals based on traditional normal approximation can lead to unsatisfactory results, with poor coverage properties. Christman and Pontius (Biometrics 56:503–510, 2000) showed that bootstrap percentile methods are appropriate for constructing confidence intervals from the HH estimator. But Perez and Pontius (J Stat Comput Simul 76:755–764, 2006) showed that bootstrap confidence intervals from the HT estimator are even worse than the normal approximation confidence intervals. In this article, we consider two pseudo empirical likelihood functions under the ACS design. One leads to the HH estimator and the other leads to a HT type estimator known as the Hájek estimator. Based on these two empirical likelihood functions, we derive confidence intervals for the population mean. Using a simulation study, we show that the confidence intervals obtained from the first EL function perform as good as the bootstrap confidence intervals from the HH estimator but the confidence intervals obtained from the second EL function perform much better than the bootstrap confidence intervals from the HT estimator, in terms of coverage rate.     

Toward an ecosystem approach to ICM: assessing ecological provinces at sea by remote sensing

The ecosystem approach requires that all elements of an ecosystem, and their mutual interactions, be taken into consideration in any management effort. The selection of suitable geographical units, where this approach can be taken, requires the assessment of ecological provinces, characterized by a coherent set of environmental traits. The marine side of coastal zones, where the interaction between atmosphere, land and sea is not bounded by evident geographic markers, represents a critical factor in this assessment. A coastal province can be defined by physical setting, but also by its bio-geo-chemical features, ideally on the basis of synoptic remote sensing data, collected at space/time scales not accessible by other means. Classifications based on indicators such as temperature, wind speed and chlorophyll-like pigments, demonstrate the identification of potential ecological provinces in the Mediterranean Sea. The results suggest remote sensing as the ideal tool to set up the basis for an ecosystem approach to the management of each province.     

Characterization and source apportionment of polycyclic aromatic hydrocarbons in the ambient air (Tehran,Iran)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the urban atmosphere and the atmospheric pollutants to be identified as the most suspected carcinogens. In early measurements of urban PAH concentrations in Tehran area, the correlation between concentrations of different species indicated that automobiles were the predominant source of emission of PAHs in this city. From the diagnostic ratios, the results indicated that PAHs in the ambient air in Tehran originate primarily from diesel and gasoline engines, but contribution of the related diesel emission is apparently higher, or dominant, at the sampling sites and therefore considered as the major emission of PAHs in the ambient air.     

Changes in chemical forms of lead in temperate and semiarid soils in sterile and unsterile conditions

Sequential extraction has been used as a suitable method for fractionation of chemical forms of trace elements and study of their plant availability. Surface soils were sampled from Guilan and Hamadan provinces in north and northwest of Iran with temperate and semiarid climates. The chemical forms of Pb in the Pb(NO₃)₂-treated (400 μg Pb g⁻¹) soils have been studied in solid state incubation (FC) at 27°C in sterile and unsterile conditions. After 20 min and 3600 h a sequential extraction scheme was also used to fractionate Pb of incubated samples into soluble-exchangeable (Sol-Exch), carbonates associated (ACar), organic matter associated (AOM), Mn oxide associated (AMnOx), Fe oxide associated (AFeOx), and residual (Res) forms. Temperate soil samples had higher clay content, cation exchange capacity (CEC), dichromate oxidable organic carbon (OC), total Kjeldahl-nitrogen (TN), biological activity, amorphous and crystalline Fe and Al, but semiarid soil samples had higher sand content, pH, equivalent calcium carbonate (ECC), available P and K. Soil lead fractionation revealed that in both groups of soils Pb largely changed to exchangeable, carbonates associated and organic associated forms after 20 min. The chemical forms of Pb differed widely among soils after 3600-h incubation. The conversion rate of Pb from more available forms to less available forms was higher in temperate soils with higher Fe–Mn oxides and OM contents compared to semiarid soils. In temperate soils after 3600-h incubation, greater content of Pb was observed in Res (68%), AOM (14%), ACar (7%), and AMnOx (5%) fractions. However, in semiarid soils greater content of Pb was observed in Res (61%), ACar (16%), Sol-Exch (8%), and AOM (8%) fractions. The sum of AMnOx and AFeOx chemical forms for Pb in semiarid soils compared to temperate soils was lower. It was only 7% against 9% in temperate soils. Soil microorganisms in unsterile soils had significant effect on AOM, AFeOx and Res fractions of Pb. They not only increased AOM and AFeOx fractions of Pb in soils but also decreased Res fraction of Pb significantly.     

Distribution and availability of potentially toxic metals in soil in central area of Belgrade,Serbia

Belgrade, capital city of Serbia, has over 1,600,000 inhabitants and over 400,000 vehicles trafficking every day on its streets. The investigation of soil pollution was performed by sequential extraction analysis to investigate the availability of potentially toxic metals (Zn, Cd, Pb, Co, Ni, Cu, Cr and Mn) under different oxidation and pH conditions. All investigated metals were mainly extracted from soils with neutral or acidic extractants. Serious pollution was observed along roads and streets with high traffic frequency, but Pb and Ni pollution was the highest since their concentrations exceed both soil Serbian standard and Canadian guidance values and is characteristic for all investigated sites. Cd, Cu, Cr and Zn concentrations are moderately high since they are between Canadian guideline and Serbian standard.     

Photochemical reaction of nitro-polycyclic aromatic hydrocarbons: effect by solvent and structure

Photochemical degradation of 1-nitropyrene, 2-nitrofluorene, 2,7-dinitrofluorene, 6-nitrochrysene, 3-nitrofluoranthene, 5-nitroacenaphthene, and 9-nitroanthracene was examined in CHCl₃, CH₂Cl₂, DMF, DMF/H₂O (80/20), CH₃CN, or CH₃CN/H₂O (80/20). The degradation mostly follows the first order kinetics; but a few follow second order kinetics or undergo self-catalysis. The photodegradation rates follow the order: CHCl₃ > CH₂Cl₂ > DMF > DMF/H₂O > CH₃CN > CH₃CN/H₂O. DMF is an exceptional solvent because three of the seven compounds undergo self-catalytic reaction. 9-Nitroanthracene, which has a perpendicular nitro group, is the fastest, while the more compact 1-nitropyrene and 3-nitrofluoranthene are the slowest degrading compounds.     

Evaluation of metabisulfite and a commercial steel wool for removing chromium(VI) from wastewater

Efficiency of metabisulfite and a commercial steel wool as reducing agents in the removal of Cr(VI) from wastewaters was evaluated. Chromium(VI) was converted to Cr(III), precipitated with NaOH, and removed by filtration. A reduction of more than 1.0 × 10⁵ and 4.0 × 10⁵ fold in total Cr and the Cr(VI) concentrations, respectively, was observed by employing steel wool masses as low as 0.4420 g to 30-mL solutions of wastewater. Chromium(III) hydroxide obtained after the treatment was recycled and used as marker in cattle nutrition studies. The liquid residue obtained after the treatment was reused as precipitation agent replacing NaOH.