Enhanced reservoir-induced earthquakes in Koyna region, India, during 1993–95

Reservoir induced earthquakes began to occur in the vicinity of Shivajisagar Lake formed by Koyna Dam in Maharashtra state, western India, soon after its filling started in 1962. Induced earthquakes have continued to occur for the past 34 years in the vicinity of this reservoir, and so far a total of 10 earthquakes of M 5.0, over 100 of M 4 and about 100,000 of M 0.0 have occurred. Every year, following the rainy season, the water level in the reservoir rises and induced earthquakes occur. Seismic activity during 1967–68 was most intense when globally, the largest reservoir induced earthquake occurred on 10 December, 1967. Other years of intense seismic activity are 1973 and 1980. During 1986 another reservoir, Warna, some 20 km south of Koyna, began to be filled. The recent burst of seismic activity in Koyna-Warna region began in August, 1993, and was monitored with a close network of digital and analog seismographs. During August, 1993–December, 1995, 1,272 shocks of magnitude 2 were located, including two earthquakes of M 5.0 and M 5.4 on 8 December, 1993 and 1 February, 1994, respectively. Two parallel epicentral trends in NNE-SSW direction, one passing through Koyna and the other through Warna reservoir are delineated. The 1993 increase in seismicity has followed a loading of 44.15 m in Warna reservoir during 11 June 11, 1993 through August 4, 1993, with a maximum rate of filling being 16 m/week. The larger shocks have been found to be preceded by a precursory nucleation process.     

Empirical assessment of adaptation to climate change impacts of mountain households: development and application of an Adaptation Capability Index

The present study proposes an index to assess the potential for adaptation to climate change for households in the mountainous regions. The index provides a realistic approach to recognize social and natural factors which contribute to successful adaptation and addresses several household functions, such as social networking, livelihood strategy, adjustment strategies, resource availability and accessibility. The proposed Adaptation Capability Index (ACI) is analytically defined, mathematically formulated and field tested on mountainous households in urban and semi-urban regions of the Uttarakhand Himalaya in India. To gather data on the topic relevant to the ACI, a household scale questionnaire was developed and administered to 120 heads of households through face-to-face interviews. The results highlight higher adaptive capability of urban households and low adaptation capacity of rural households due to poor farm productivity, low accessibility and availability of resources and technological input. Future programs and policies must include and implement regulations to remedy attributive factors responsible for higher adaptation. This paper may be applicable to other mountainous regions and may provide insights for effective adaptation strategies to climate change.     

Hydrogeochemical investigation and qualitative assessment of surface water resources in West Bokaro coalfield,India

A hydrogeochemical study of surface water of the West Bokaro coalfield has been undertaken to assess its quality and suitability for drinking, domestic and irrigation purposes. For this purpose, fourteen samples collected from rivers and ponds of the coalfield were analysed for pH, conductivity, total dissolved solids (TDS), major cations (Ca²⁺, Mg²⁺, Na⁺ and K⁺), major anions (HCO₃^-, F^-, Cl^-, SO₄^2- and NO₃^-) and trace metals. The pH of the analysed water samples varied from 7.3 to 8.2, indicating slightly alkaline in nature. The electrical conductivity (EC) value varied from 93 μs cm^-1 to 906 μs cm^-1 while the TDS varied from 76 mg L^-1 to 658 mg L^-1. HCO₃^- and SO₄^2- are the dominant anion and Ca²⁺ and Na⁺ the cation in the surface water. The concentration of alkaline earth metals (Ca²⁺ + Mg²⁺) exceed the alkali metals (Na⁺ + K⁺) and HCO₃^- dominates over SO₄^2- + Cl^- concentrations in the majority of the surface water samples. Ca²⁺ -Mg²⁺ -HCO₃^- and Ca²⁺ -Mg²⁺ -Cl^- are the dominant hydrogeochemical facies in the surface water of the area. The water chemistry is mainly controlled by rock weathering with secondary contribution from anthropogenic sources. For quality assessment, analyzed water parameter values compared with Indian and WHO water quality standard. In majority of the samples, the analyzed parameters are well within the desirable limits and water is potable for drinking purposes. However, concentrations of TDS, TH, Ca²⁺, Mg²⁺ and Fe are exceeding the desirable limits in some water samples and needs treatment before its utilization. The calculated parameters such as sodium absorption ration, percent sodium, residual sodium carbonate, permeability index and magnesium hazard revealed good to permissible quality and suitable for irrigation purposes, however, higher salinity, permeability index and Mg-ratio restrict its suitability for irrigation at few sites.     

Advanced oxidation of catechol in reverse osmosis concentrate generated in leather wastewater by Cu–graphite electrode

Reverse osmosis (RO) concentrate generated from tannery was treated by advanced electrochemical oxidation using graphite electrodes. Catechol was selected as model organic pollutant in the RO concentrate. The influence of applied current density, catechol concentration, pH, temperature and inner electrode space of electrodes was investigated in electrochemical oxidation system. The optimized conditions were found to be current density (j), 100 mA/cm²; electrolysis time (t _eco), 60 min; pH, 7.0; and temperature, 25 °C at an inner electrode space, 2 cm. The average mass transport coefficient for the removal of catechol as COD was found to be 3.0 × 10^?5 m/s at optimum conditions. Faradic efficiency and specific energy consumption were also calculated for the applied current density. Further, the treatment of catechol was confirmed through Fourier transform infrared spectroscopy. Theoretical evaluation of current density suggested that the removal of catechol was controlled when supplied at above limiting applied current densities and mass transport controlled at lower of limiting current densities.     

Assessment of freely available CartoDEM V1 and V1.1R1 with respect to high resolution aerial photogrammetric DEM in high mountains

The accuracy of DEMs shows wide variations from one terrain to another and it needs to be determined. This study evaluates NRSC (National Remote Sensing Centre, Hyderabad, India) CartoDEM V1 and V1.1R1 with respect to resampled ADS80 DEM for parts of the Himalayas. Both the test DEMs were properly registered with reference to resampled ADS80 DEM and then individually subtracted to get the difference DEMs. Visual and statistical analyses were performed to assess the quality of the tested DEMs in terms of visible terrain and vertical accuracy. For calculating the accuracies in different terrain classes, slope and aspect maps were generated from the ADS80 DEM. Properly registered Landsat5 TM data were used for the development of the land cover map with four classes. The overall vertical accuracy measured for CartoDEM V1 was 269.9 m (LE90), while CartoDEM V1.1R1 showed huge improvement in the accuracy with 68.5 m (LE90).     

Long period Pc5 pulsations

The characteristics of long period Pc5 pulsations (frequency 3·33-1·67 mHz; period 300–600 sec) for stations in the subauroral, auroral and polar zones are studied for 1967. These pulsations occur mainly in the auroral and polar zones with one morning and one evening peak; in the cusp region they occur most frequently near local noon. The evening peak gets stronger and appears farther away from noon with increasing geomagnetic activity. Periods are shorter and amplitudes larger in the morning compared to the evening hours. Only in a small latitudinal belt (60–70°) do the periods tend to increase with latitude. Amplitudes are almost always maximum near the central line of the auroral zone and drop much more sharply towards lower latitudes than towards higher latitudes. Considerable diurnal variations and also variations with magnetic activity are found to exist in the occurrence-latitude and amplitudelatitude profiles. In all the three regions the occurrence and the amplitude of these pulsations increase with magnetic activity to a certain level after which results become uncertain. Periods either do not change very much or at some stations decrease as activity increases.     

Benthic foraminifera of bathyal hydrocarbon vents of the Gulf of Mexico: Initial report on communities and stable isotopes

Substrates associated with active hydrocarbon vents in bathyal Gulf of Mexico support numerous foraminiferal species, with a few of them showing unusually high relative abundances. In the 584- to 695-m-depth range,Bolivina ordinaria, Gavelinopsis translucens, andCassidulina neocarinata strongly dominate the vent community, whereasBolivina subaenariensis andUvigerina laevis play this role around a vent at 216 m water depth. The bathymetric imprint on the foraminiferal record is also seen in the ¹⁸O compositions of some species, includingUvigerina peregrina. The adaptation of foraminiferal communities to bacterial (Beggiatoa) mats, in which the redox boundary is very close to the sediment—water interface, and anomalous depletions of¹³C inU. peregrina (relative to the same species from nonventing sites) indicate that several species are probably facultative anaerobes and tolerant of H₂S toxicity.