Air-sea interaction over the tropical Indian Ocean during several contrasting monsoon seasons

Monthly mean anomaly fields of various parameters like sea surface temperature, air temperature, wind stress, effective radiation at the surface, heat gain over the ocean and the total heat loss between a good and bad monsoon composite and the evaporation rates over the Arabian Sea and southern hemisphere have been studied over the tropical Indian Ocean. The mean rates of evaporation on a seasonal scale over the Arabian Sea during a good and bad monsoon composites were equal (about 2·48 × 10¹⁰ tons/day). The evaporation rates over the southern hemisphere were greater during all the months. The mean evaporation rates over the southern hemisphere on a seasonal scale for the good and bad monsoon composites were 4·4 × 10¹⁰ and 4·6 × 10¹⁰ tons/day respectively. The maximum evaporation rates over the southern hemisphere were observed in August. The anomalies of wind stress, effective radiation at the surface and the heat gain over the ocean also exhibit large variations in August, as compared to other monsoon months.     

Surface wave propagation in a transversely isotropic elastic layer overlying a liquid saturated porous solid half-space and lying under the uniform layer of liquid

Dispersion of Rayleigh-type surface wave is studied in a homogeneous transversely isotropic elastic layer overlying a nondissipative liquid-saturated porous solid half-space and lying under a uniform layer of homogeneous liquid. The frequency equation in the form of ninth-order determinant is obtained.Special cases have been deduced by reducing the depth of the layers to zero and by changing the transverse isotropic layer to an isotropic layer. Dispersion curves for the phase velocity have been plotted for a particular model.     

The Fauna of Different Drinking Water Sources of Bhagalpur,India

In three drinking water sources i. e. river, well and filter water, there were detected 50 taxa of animals: 10 amoebae and 2 ciliates (protozoa), 24 rotifera, 5 cladocerans, and 9 copepods. Chief components of the rotifers population were Brachionus and Keratella, although K. cochlearis is the most common form at all the sites. The presence of Entamoeba histolytica in well water was indicative of faecal contamination which may become a causative agent of amoebiasis in human beings.     

Water Quality,Phytoplankton Diversity and Production in G. B. Pant Sagar at Rihand Dam,Pipri

The man made reservoir, G. B. Pant Sagar at the dam site (24° 15′ N Lat) in the South Mirzapur district of eastern U. P. was investigated in terms of water quality, phytoplankton diversity and production at monthly intervals between January 1987 and December 1987. The reservoir water showed low to moderate dissolved oxygen (4.3 … 7.5 mg/l) and quite low nutrient contents (0.01-0.2 mg l^?1). Phytoplankton diversity narrowly fluctuated (3.17-3.74) and mean annual production (149.7 g/m³ · aC) showed a meso- to eutrophic condition. A significant positive correlation was obtained between gross production and phytoplankton density (r = 0.79; P < 0.001) Multiple regression equation (GPP = 11.292 + 0.043 BAC + 0.075 CHL + 0.073 CYN) indicates that Chlorophyta contributed more to gross production due to the presence of a higher number of individuals.     

Deforestation,climate change and sustainable nutrition security: A case study of India

Wheat and rice are the most important crops from the point of view of maintaining a sustainable nutrition security system for India, a country whose population may reach one billion by the year 2000. The implications of climate change deriving from tropical deforestation, particularly as concerns temperature and precipitation, with reference to the yield of wheat and rice in different parts of India are hence being studied carefully. Any possible positive gain arising from increased CO₂ concentration is likely to be offset by the yield decline induced by higher temperature and shorter growing period.Professor of Eminence, Water Technology Centre, IARI.President, National Academy of Agricultural Sciences of India and Past President of the International Union for the Conservation of Nature and Natural Resources (IUCN).     

On a Class of Solitary Wave Solutions of Atmospheric Nonlinear Equations

In this paper, an attempt is made to study some interesting results of the coupled nonlinear equations in the at-mosphere. By introducing a phase angle function ξ, it is shown that the atmospheric equations in the presence of specific forcing exhibit the exact and explicit solitary wave solutions under certain conditions.     

Static deformation of two welded half-spaces due to very long strike-slip dislocations

Closed form analytic expressions for displacement and stresses at any point of either of the two homogeneous, isotropic, perfectly elastic half-spaces in welded contact due to very long strike-slip dislocations are obtained. Both cases of vertical and horizontal strike-slip dislocations are discussed in detail. Variation of the displacement with horizontal distance from the fault and with vertical distance from the interface for a vertical strike-slip fault is studied numerically.     

A Leaky Aquifer Model For Hard Rock Aquifers

A comparison is made between the unsteady parallel fracture model using the double porosity approach and the anisotropic aquifer-water table aquitard system. The presence of a moving water table in the weathered zone (unconfined block), influenced by recharge from rainfall or other sources and leakage to the fracture zone, is discussed. The effect of fracture skin on the block-fracture interface is studied for both double-porosity and aquifer-water table aquitard systems. Typical type curves are presented. It is found that the effect of both fracture skin and water table is to lead to a flat drawdown behaviour for a large time. The applicability of the present model for parameters estimation is illustrated on a field pumping test of 7 days duration.

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Résumé: Une comparaison a étéétablie entre le modèle de fractures non constamment parallèles utilisant l'approche de la double porosité et une système composé d'un aquifère anisotrope et un bloc de faible perméabilité avec une surface libre. La présence d'une surface libre variable dans la zone d'altération (bloc non captif), inflluencée par la recharge (pluie ou autre) et par l'écoulement vers la zone fracturée, est discutée. L'effet d'une conche superficielle à l'interface bloc-fracture est étudié pour les deux systèmes, celui à double porosité et celui composé d'un aquifère et d'un bloc de faible perméabilité. Des combes typiques sont montrées. Les résultats montrent que les effets d'une conche superficielle et de la surface de la nappe conduisent à une evolution constante en rabattement pour un temps long. L'application du modèle pour l'estimation des paramètres est justifiée par les résultats d'un pompage d'essai de 7 jours.