Geo-environmental quality assessment in Jharia coalfield,India, using multivariate statistics and geographic information system

A study on geo-environmental quality assessment in Jharia coalfield, India, has been attempted using multivariate statistical analysis and geographic information system (GIS) modelling techniques. Water quality index, calculated for each sample network station in the study area to assess the suitability of water for human consumption, revealed very poor to poor quality surface water and mine water. Air quality indexing indicated that there is no sample station with clean air as per the Indian standards, which indicate the hazardous air quality. Multi-criteria evaluation (MCE), a potential GIS tool, has been applied to the delineation of various degrees of stressed villages in terms of quality of life (QoL). The role of various geo-environmental parameters such as quality of groundwater, surface water, mine water and air together with village population densities has been emphasized for delineation of the environmentally stressed villages in Jharia coalfield. The integrated cluster analysis and MCE approach provide an improved means to geo-environmental quality assessment in Jharia coalfield in terms of QoL. The assessment study is aimed to be used for future coal mining, ensuring ecologically sustainable industrial development, particularly in a coalfield.     

Use of remote sensing,GIS and C++ for soil erosion assessment in the Shakkar River basin,India

Soil is an essential resource for human livelihoods. Soil erosion is now a global environmental crisis that threatens the natural environment and agriculture. This study aimed to assess the annual rate of soil erosion using distributed information for topography, land use and soil, with a remote sensing (RS) and geographical information system (GIS) approach and comparison of simulated with observed sediment loss. The Shakkar River basin, situated in the Narsinghpur and Chhindwara districts of Madhya Pradesh, India, was selected for this study. The universal soil loss equation (USLE) with RS and GIS was used to predict the spatial distribution of soil erosion occurring in the study area on a grid-cell basis. Thematic maps of rainfall erosivity factor (R), soil erodibility factor (K), topographic factor (LS), crop/cover management factor (C), and conservation/support practice factor (P) were prepared using annual rainfall data, soil map, digital elevation model (DEM) and an executable C++ program, and a satellite image of the study area in the GIS environment. The annual rate of soil erosion was estimated for a 15-year period (1992–2006) and was found to vary between 6.45 and 13.74 t ha^?1 year^?1, with an average annual rate of 9.84 t ha^?1 year^?1. The percentage deviation between simulated and observed values varies between 2.68% and 18.73%, with a coefficient of determination (R²) of 0.874.     

Corrected Hawking temperature of (2+1) dimensional BTZ (Banados-Teitelboim-Zanelli) rotating Black Hole by using tunneling method

We study the (2+1) dimensional BTZ (Banados-Teitelboim-Zanelli) rotating Black Hole. Along with the scalar field it obeys the Klein-Gordon equation of motion. We use the dragging coordinate system to isolate the r–t sector from the metric. By considering the massless particle and scalar field, we calculate the corrected Hawking temperature with the help of tunneling method.     

Rotational distortion of the stars of arbitrary structure: Fourth approximation

Clairaut's theory of the rotational distortion of self-gravitating configurations of arbitrary structure, arising from axial rotation with constant angular velocity, previously developed (cf. Kopal, 1973) to quantities of third order in superficial distortion, has now been extended to terms of fourth order. The differential equations governing the form and exterior potential of stars so rotating have been set up by the method followed in our previous paper (Kopal, 1973) together with their boundary conditions; but their applications to practical cases are being postponed for a subsequent investigation.Work carried out partly at the Naval Research Laboratory, Washington, D.C., U.S.A.     

Goethite Morphology and Composition in Banded Iron Formation, Orissa, India

Iron ore deposits are generally described in terms of size, grade and chemical composition rather than the mineralogical and microstructural characteristic of different ore types. It is essential, however, to know the morphology, microstructure and chemical composition of individual minerals for optimum mineral processing. Goethite is reported to occur as a ubiquitous phase in many iron ore types and is particularly abundant in the Precambrian banded iron ore formation of north Orissa, India. Goethite from the Bonai–Keonjhar Belt in Orissa has been examined in terms of its morphology and microstructure in relation to chemical composition. Electron microscopy indicated several goethite morphotypes including botryoidal, nodular, spheroidal, platy, stalactitic and flaky. These different morphotypes display intergranular, intragranular, wedge, reniform, comb, prismatic, cavity-line and bead microstructures. In situ analysis using electron probe microanalyzer indicated a wide compositional variation among the different morphotypes and microstructures. Goethite replacing hematite is generally devoid of deleterious elements while re-precipitated goethite generally contains adsorbed alumina, silica and/or phosphorus. Nodular goethite commonly has a high phosphorus level while botryoidal, spheroidal and platy goethite often contains increased combined alumina and silica. Goethite having a reniform, wedge, intergranular or intragranular microstructure is highly water bearing and cryptocrystalline in nature. During dehydration, bead, comb, cavity-lined or prismatic goethite develop, which are more crystalline and which have a higher iron concentration. Goethite with a wedge, prismatic or bead-type microstructure has a higher adsorption of silica (2–4%), while goethite having an intergranular, bead or prismatic microstructure invariably contains appreciable phosphorus, generally at levels deleterious to processing.     

Five dimensional LRS Bianchi type-I string cosmological model in Saez and Ballester theory

In this paper, it is shown that five dimensional LRS Bianchi type-I string cosmological models do not survive for Geometric and Takabayasi string whereas Barotropic string i.e. ρ=ρ(λ) survives and degenerates string with ρ+λ=0 in scalar tensor theory of gravitation proposed by Saez and Ballester (Phys. Lett. A 113:467, 1986). Further we studied some physical and geometrical properties of the model.     

Coupling Between Seismic Activity and Hydrogeochemistry at the Shillong Plateau, Northeastern India

Transient hydrogeochemical anomalies were detected in a granite-hosted aquifer, which is located at a depth of 110 m, north of the Shillong Plateau, Assam, India, where groundwater chemistry is mainly buffered by feldspar alteration to kaolinite. Their onsets preceded moderate earthquakes on December 9, 2004 (M_W = 5.3) and February 15, 2005 (M_W = 5.0), respectively, 206 and 213 km from the aquifer. The ratios [Na+K]/Si, Na/K and [Na+K]/Ca, conductivity, alkalinity and chloride concentration began increasing 3–5 weeks before the M_W = 5.3 earthquake. By comparison with field, experimental and theoretical studies, we interpret a transient switchover between source aquifers, which induced an influx of groundwater from a second aquifer, where groundwater chemistry was dominantly buffered by the alteration of feldspar to smectite. This could have occurred in response to fracturing of a hydrological barrier. The ratio Ba/Sr began decreasing 3–6 days before the M_W = 5.0 earthquake. We interpret a transient switchover to anorthite dissolution caused by exposure of fresh plagioclase to groundwater interaction. This could have been induced by microfracturing, locally within the main aquifer. By comparison with experimental studies of feldspar dissolution, we interpret that hydrogeochemical recovery was facilitated by groundwater interaction and clay mineralization, which could have been coupled with fracture sealing. The coincidence in timing of these two hydrogeochemical events with the only two M_W ≥ 5 earthquakes in the study area argues in favor of cause-and-effect seismic-hydrogeochemical coupling. However, reasons for ambiguity include the lack of similar hydrogeochemical anomalies coupled with smaller seismic events near the monitoring station, the >200 km length scale of inferred seismic-hydrogeochemical coupling, and the potential for far-field effects related to the Great Sumatra–Andaman Islands Earthquake of December 26, 2004.     

Arsenic distribution along different hydrogeomorphic zones in parts of the Brahmaputra River Valley,Assam (India)

The spatial distribution of arsenic (As) concentrations along three classified hydrogeomorphological zones in the Brahmaputra River Valley in Assam (India) have been investigated: zone I, comprising the piedmont and alluvial fans; zone II, comprising the runoff areas; and zone III, comprising the discharge zones. Groundwater (150 samples) from shallow hand-pumped and public water supply wells (2–60 m in depth) was analysed for chemical composition to examine the geochemical processes controlling As mobilization. As concentrations up to 0.134 mg/L were recorded, with concentrations below the World Health Organization and the Bureau of Indian Standards drinking-water limits of 0.01 mg/L being found mainly in the proximal recharge areas. Eh and other redox indicators (i.e., dissolved oxygen, Fe, Mn and As) indicate that, except for samples taken in the recharge zone, groundwater is reducing and exhibits a systematic decrease in redox conditions along the runoff and discharge zones. Hydrogeochemical evaluation indicated that zone I, located along the proximal recharge areas, is characterized by low As concentration, while zones II and III are areas with high and moderate concentrations, respectively. Systematic changes in As concentrations along the three zones support the view that areas of active recharge with high hydraulic gradient are potential areas hosting low-As aquifers.