Journal of Geological Society of India (Online archive from Vol 1 to Vol 78)

Vijay Kumar ¹

Affiliations
1 Department of Geology, Ranchi College, Ranchi 834 008, Bihar, IN

Abstract

Carbonization properties increase very sharply with increasing proportions of reactives and reactive indicesi.e., they are directly proportional to each other. The samples giving coke types between G and G3, caking indices between 19/21 and 29/31 and swelling indices between 2 and 5 1/2 with reactives between 56.6% and 70.1% and reactive indices between 1.30 and 2.34 are prime coking in characters. The samples giving coke types above G3, between G3/G4 and G8/G9 and below G, between D/E and F/G may be utilised as primary blends in coal preparation for the manufacture of metallurgical coke.

Both sulphur and phosphorous are within permissible limits for coals to be treated as coking to prime coking. Ash in the coal seams may be brought down by beneficiation within permissible limits for metallurgical coke. The beneficiation will also help to improve the presently determined carbonization properties and to decrease sulphur and phosphorous contents in the seams.

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Vijay Kumar ¹

Affiliations
1 National Institute of Hydrology, Roorkee - 247 667, IN

Abstract

The command areas of canal irrigation projects in Rajasthan face the problem of rising groundwater level and manifestation of waterlogging at many places. To delineate the extent of waterlogged area, contour mapping of groundwater levels is required, which in turn require the interpolation of groundwater levels, measured in field at random points, at the grid nodes. In this paper, the applicability and usefulness of kriging to interpolate and map the spatial behaviour of groundwater levels has been demonstrated through a case study. Kriging is applied to interpolate the groundwater levels (above mean sea level) measured at 67 points in pre-Monsoon season and at 61 points in post-Monsoon season of 1991 in parts of the command area of Indira Gandhi Nahar Pariyojana (IGNP). With the use of measured elevations of the water table (above mean sea level), experimental semivariograms were constructed for both the seasons. Spherical, exponential and gaussian theoretical semivariogram models were fitted to the experimental semivariograms. The finally selected models were used to estimate the groundwater levels and corresponding standard deviation at the nodes of a square grid of 5km x 5km and to develop corresponding contour maps. The effect of using a common semivariogram, parameters estimated by taking the arithmetic mean of the semivariogram parameters for June and September data sets, on the cross validation results is also investigated.

Keywords

Kriging, Groundwater Levels, Interpolation, Semivariogram, Indira Gandhi Nahar Pariyojana (IGNP), Rajashthan.

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S. P. Rai ¹, Vijay Kumar ¹, Omkar Singh ¹, Bhishm Kumar ², S. K. Jain ²

Affiliations
1 National Institute of Hydrology, Western Himalayan Regional Centre, Satwari Jammu Cantt (J&K) 180 003, IN
2 National Institute of Hydrology, Jalvigyan Bhawan, Roorkee (U A ) - 247 667, IN

Abstract

An attempt has been made to workout the bathymetry, determine the rate of sedimentation and the physico-Chemical characteristics of the Mansar lake of Jammu region. The bathymetric survey conducted using Range-Line method shows present lake surface area is 0 59x10⁶ m² and volume to be 11 57x10⁶ m³. The rate of sedimentation determined using ¹³⁷Cs and ²¹⁰Pb radiometric dating technique in the lake varies between 0 14 cm/y to 0 37 cm/y with a mean rate of 0 23 cm/y±0 002 cm/y. The variation of temperature, pH, electrical conductivity, dissolved oxygen, hardness and alkalinity suggest that Mansar lake undergoes two distinct stages, viz complete mixing stage in the months of January and February and stratified stage in other months. The catchment lithology contributes a large part of the major constituents in lake water, Ca and Mg account 70 to 85% of the cations and HCO₃ accounts for 77 to 91% of the total anion, and equivalent ratio of Ca Mg varies from 0 45 to 6 40. The average (Ca+Mg)/HCO₃ equivalent ratio of 1 04, major contribution of (Ca+Mg) to total cations and high (Ca+Mg)/(Na+K) ratio indicate that weathering of calcareous sandstones and mudstones of the Siwalik Group could be the primary source of major ions in the lake water. Results of phosphorous show that Mansar lake has entered the eutrophic stage.

Keywords

Bathymetry, Sedimentation Rate, ¹³⁷Cs and ²¹⁰Pb Dating, Stratification, Hydrochemistry, Mansar Lake, Jammu and Kashmir.

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