Determination of the utility of groundwater with respect to the geochemical parameters: a case study from Tuticorin District of Tamil Nadu (India)

In modern living, rapid development has created an increase in demand for groundwater. An endeavor has been made to understand the hydrogeochemical parameters to determine the utility of groundwater. This situation is severe in coastal hard rock aquifers due to the influence of salinity ingression and other anthropogenic influence. A total of 135 groundwater samples were collected from the coastal aquifer of the Tuticorin district and analyzed for major cations and anions during premonsoon (PRM) and postmonsoon (POM). The ions analyzed were used to determine the drinking, agricultural and domestic utility of groundwater. The electrical conductivity (EC) contour shows that the groundwater quality is poor along the coast. The parameters were compared with WHO (Guidelines for drinking water quality recommendations, WHO, Geneva, 2004) standard for drinking purpose. A groundwater classification method has been developed for groundwater in the area using a dynamic water quality index (WQI). On the basis of the WQI so computed, groundwater in the area has been spatially classified into “excellent,” “good,” “poor” and “very poor” to “Unsuitable” water types variation lithologywise. Corrosivity ratio and hardness were noted to be higher and found to be unsuitable in majority of the regions for domestic purpose. Higher fluoride concentration was noted in the central part of the study area represented by complex geology comprising of the hornblende biotite gneiss and charnockite. Sodium percentage (Na%), sodium absorption ratio, residual sodium carbonate, Wilcox (Classification and use of irrigation waters, US Department of Agriculture, Washington, 1955), permeability index, residual sodium bicarbonate, magnesium hazard, Kelly’s ratio and potential salinity also indicate that most of the groundwater samples are not suitable for irrigation purposes.     

Development of vegetative and generative organs in magnetic orientation types of radish in a weak permanent magnetic field

Experiments have been performed to evaluate the impact of weak permanent horizontal magnetic field of about 400 A/m on seed formation in the main magnetic orientation types of radish, the north-south (NS) and west-east (WE) types. The results show that external magnetic field exposure retards plant progression through all stages of ontogeny but does not alter the ratio of NS and WE types. Under its effect, the numbers of pods and seeds and seed weight decrease in the NS-type but increase in the WS-type plants. Therefore, external magnetic field acts as an ecological factor that differentiates the responses of radish plants depending on the type of their magnetic orientation. Differences in the sensitivity of plants to magnetic field exposure are explained by specific features of their physiological status.     

Projecting current and potential future distribution of the Fire-bellied toad Bombina bombina under climate change in north-eastern Germany

Environmental change is likely to have a strong impact on biodiversity, and many species may shift their distribution in response. In this study, we aimed at projecting the availability of suitable habitat for an endangered amphibian species, the Fire-bellied toad Bombina bombina, in Brandenburg (north-eastern Germany). We modelled a potential habitat distribution map based on (1) a database with 10,581 presence records for Bombina from the years 1990 to 2009, (2) current estimates for ecogeographical variables (EGVs) and (3) the future projection of these EGVs according to the statistical regional model, respectively, the soil and water integrated model, applying the maximum entropy approach (Maxent). By comparing current and potential future distributions, we evaluated the projected change in distribution of suitable habitats and identified the environmental variables most associated with habitat suitability that turned out to be climatic variables related to the hydrological cycle. Under the applied scenario, our results indicate increasing habitat suitability in many areas and an extended range of suitable habitats. However, even if the environmental conditions in Brandenburg may change as predicted, it is questionable whether the Fire-bellied toad will truly benefit, as dispersal abilities of amphibian species are limited and strongly influenced by anthropogenic disturbances, that is, intensive agriculture, habitat destruction and fragmentation. Furthermore, agronomic pressure is likely to increase on productive areas with fertile soils and high water retention capacities, indeed those areas suitable for B. bombina. All these changes may affect temporary pond hydrology as well as the reproductive success and breeding phenology of toads.     

Plant species richness of riverbed elevations—the Pripyat river valley case study

Flora of the still unchanged or slightly modified floodplains is particularly valuable. Such are the natural, periodically flooded riparian ecosystems within the Mid-Pripyat river valley in Belarus. Distinctive elements of that area are ‘periodic islands’, which arise from the most elevated parts of the riverbed during flooding and have a specific microtopography. The aim of the research was to recognize floristic composition and ecological conditions of the ‘islands.’ Noted plants were mainly photophilous, by clearly varied in soil moisture, acidity and fertility requirements.     

Efficiency of natural reproduction of sturgeons in the lower Volga under current conditions

The results are presented that have been obtained during long-term studies (1991–2009) on the efficiency of natural reproduction of the beluga, Russian sturgeon, stellate sturgeon, and sterlet in different spawning zones of the Volga. The influence of major environmental factors on the formation of the offspring of these fishes is analyzed. It is shown that the productivity of Volga spawning grounds varies depending on the river flow volume during spring floods and the abundance of active spawners. Practical recommendations are proposed for enhancing sturgeon reproduction in the Volga.     

Effect of anthropogenic pollution on oxidative processes in the liver of fish from the Rybinsk Reservoir

The levels of total lipids, peroxidation products, and antioxidant activity in the liver were studied in fish species living in unequally polluted areas of the Rybinsk Reservoir and differing in their ecology and taxonomic position: the bream (Abramis brama L.), roach (Rutilus rutilus L.), burbot (Lota lota L.), and zander (Stizostedion lucioperca L.). The fish from polluted water areas were characterized by higher levels of total lipids and malonic dialdehyde and a deficiency of antioxidants. It is shown that the test parameters depend on the type of feeding and mode of life of the fish species.     

A Multivariable Model for Atmospheric Dispersion Predictions

In conjunction with a 15-month air quality survey of Jacksonville, Fia., a mathematical model has been developed to describe the dispersion of atmospheric pollutants. The source inventory used with the model was compiled, in part, from the data obtained from the sampling of all major sources within the area. The major sources were considered separately from the one-mile square area sources which accounted for the remainder of the emissions. Meteorological data was recorded continuously in the city including vertical temperature observations to 750 ft. The model was compiled in FORTRAN and can be used for both gaseous and particulate pollutants, by utilizing proper decay rates. The variant nature of meteorological parameters and emission rates are considered. The ground level concentrations of several pollutants which were determined for 24 hr periods at 11 sites and continuously at two other sites were used to check the model. A limited tracer study was carried out in conjunction with the project.     

A Note on Comparison of Statistical and Analytical Results for Calculating Oxides of Nitrogen Concentrations

A question often asked about analytical diffusion models is “How do the analytical results for calculating pollution concentrations compare with those obtained by statistical techniques?” Miller and Holzworth (1967) have developed a simple analytical diffusion model that yields relative pollution concentrations, x/Q, as a function of afternoon mixing depth, mean transport wind speed, and city size. This analytical model may also be used in reverse to determine apparent afternoon source strengths from observed afternoon pollution concentrations. The apparent source strengths may then be used with the model on independent data to estimate pollution concentrations. It is the purpose of this note to compare results of calculating average afternoon concentrations of oxides of nitrogen (NO_x) by use of the Miller-Holzworth model with those obtained from statistical regression equations.     

Limitations of the Lead Acetate Impregnated Paper Tape Method for Hydrogen Sulfide

Field experience with the lead acetate impregnated paper tape sampler has indicated that large errors may arise in this method due to fading of the color of the precipitated lead sulfide spots. This fading is due to the action of light, sulfur dioxide, ozone, on other substances capable of oxidizing lead sulfide. The moisture content or relative humidity of the air sample must be maintained at an appropriate level to ensure reaction with the impregnated paper tape. The effects of the factors have been investigated in laboratory experiments with known concentrations of H₂S. A number of antioxidants were studied in relation to the stability of the resultant spots to light and oxidation Orthophenyl phenol was found to be the most effective antioxidant for this purpose. A number of necessary precautions to be employed in the use of the lead acetate method are recommended and the limitations are discussed.