001192   Rajmohan N;Elango L;Ramachandran S;Natarajan M (NO, Institute of Ocean Management, Anna University, Chennai 25) : Major ion correlation in groundwater of Kancheepuram region, South India. Indian J envir Hlth 2003, 45(1), 5-10.

Groundwater samples were collected from both dugwells and borewells in an intensively irrigated area of Kancheepuram Taluk, Tamil Nadu. pH, EC and TDS of groundwater samples were measured in the site. The collected samples were analysed in the laboratory for Ca,Mg,Na,K,Cl,HCO₃,CO₃,SO₄,NO₃,P-PO₄ and Si-SiO₂. The results are used for inter elemental correlation analysis which indicates that most of the elements having good correlation. Piper Trilinear diagram is used to find out the hydrochemical type of groundwater which shows that most of them are CaHCO₃ and the remaining are CaMgCl type. Hydrochemical characteristics of groundwater indicate that silicate weathering reaction is a probable source for high concentration of major ions.

3 illus, 3 tables, 7 ref

001191   Raj R (Department of Geology, Faculty of Science, University of Baroda, Vadodara-390 002) : Fluvial response to late quaternary tectonic changes in the Dhadhar river basin, Mainland Gujarat. J Geol Soc India 2004, 64(5), 666-76.

The study aims at reconstruction of the Dhadhar drainage system during Late Quaternary applying geomorphic and stratigraphic criteria. Remote sensing data show occurrence of palaeodrainages in the area between the Dhadhar and Orsang Rivers. The exposed sediment records of these river basins, lakes and ponds mainly in the areas where there is no drainage help in reconstructing the palaeodrainage. The exposed sediment succession in the lakes and ponds show a thick fluvial sequence (GM and Sh) overlain by a 4-5 m thick black organic rich finely laminated lacustrine clays (FC). The sedimentary records and mineralogy of the Dhadhar and Orsang basins are quite similar and correlatable. The course of Orsang River which flowed through the Dhadhar River during Late pleistocene was changed during Early Holocene due to tectonic uplift along the major faults in the area.

4 illus, 40 ref

001190   R Mise S;Rajamanya V S (Department of Civil Engineering, P D A College of Engineering, Gulbarga) : Adsorption studies of chromium (VI) on activated carbon derived from Sorghum Vulgare (dried stem of jowar). Indian J envir Hlth 2003, 45(1), 49-58.

Deals with the adsorption studies of chromium (VI) on activated carbon derived from Sorghum vulgare (dried stem of Jowar). The activated carbons were prepared by physical and chemical activation using H₂SO₄, H₃PO₄ activating agents of different imprignation Ratio (I R). The effect of adsorption of Cr (VI) on pH, particle size concentration, contact time and dosage have been studied. Removal of chromium (VI) attained in equilibrium maximum of 50 minutes and slightly decreases with increasing I R. Adsorption obeys first order rate equation and Webber and Morris equation for pore diffusion. Adsorption increases with decrease in pH, is maximum at pH 2. Increase in impegnation ratio also increases surface area of Sorghum vulgare carbons.

11 illus, 10 tables, 7 ref

001189   Pironneau O (Laboratoire Jacques-Louis Lions, Univ Paris VI - IUF, Paris, France) : Discontinuous data assimilation. Proc Indian Natn Sci Acad-Pt A 2003, 69(5), 473-8.

Data Assimilation is important in meteorology, oceanography and climatology because it is a way to improve the models with newly measured data, statically or dynamically. The problem is well known in control and system theory and a large number of methods applied to environmental sciences are issued from Kalman filters, optimal control etc. Gives a short review of data assimilation by least squares and optimal control and then concentrate on the problem of finding a discontinuity known to be present in the data but of unknown position in space, such as a meteorological front. As standard control theory assumes differentiability, there are new mathematical difficulties here; if gradient methods are to be used computationally, one needs to establish that derivatives exists in the sense of L¹ instead of L².Ite shows on simple examples the difficulties and give some numerical solutions for some flows with shocks.

1 illus, 25 ref

001188   Pielke R A;Dutta D;Niyogi S;Chase T N;Eastman J L (1371, Campus Delivery, Atmospheric Sci Dep, Colorado State Univ, Fort Collins, CO 80523-1371, USA) : A new perspective on climate change and variability: a focus on India. Proc Indian Natn Sci Acad-Pt A 2003, 69(5), 585-602.

Overviews the global context of climate change in terms of the Earth's heat budget. It is shown that the Earth's climate system, as the major store for heat, has warmed less than suggested by the IPCC reports. In terms of top of the atmosphere radiative heating, globally-averaged radiative imbalance between 1955-1995 is about 0.3 W m^-2. Focuses on India and discusses the role of land-use change, vegetation dynamics, and aerosols in altering the regional climate on India. The current and natural landscape of the region is illustrated with 50 km horizontal grid scales and the effect on India's weather and climate is simulated using the NCAR CCM3 GCM. Using NDVI satellite data, vegetation growth is shown to be closely correlated with precipitation that fell two months earlier. Aerosols are shown to significantly alter the direct and diffuse sunlight that reaches vegatation, which subsequently has an effect on carbon assimilation and transpiration. Population increases are presented as a primary driver of these regional climate changes in India.

11 illus, 61 ref

001187   Patil V D;Phulari P S (Civil Engng Dep, Govt Coll of Engng, , Pune 411 005) : Cathodic protection system for underground M S pipeline of water supply project. Indian J envir Hlth 2003, 45(1), 11-4.

Corrosion of steel embedded in soil can generally by explained in terms of long cell action arising from differential aeration. The significant factors to promote corrosion are soil potential, resistivity and draining characteristics. As the corrosive nature of soil is not fixed absolute value, the said study can be analyzed by adopting the following methodology. Study of state of soil at different location. Nature of corrosion under consideration. With above methodology an attempt can be made to achieve the following objective to, assess the extent of corrosive tendencies of soil along the pipeline. Co-relate potential and resistivity with corrosive parameters of soil and suggest the appropriate remedial means for protecting it from corrosion. i.e. Galvanic activity.

3 tables, 11 ref

001186   Nagalakshmi T;Achyuthan H (Department of Geology, Anna University, Chennai-600 025) : Radiocarbon dating and holocene episodes of alluvial sedimentation in the Koratallaiyar-Cooum river basin, Chennai, South India. J Geol Soc India 2004, 64(4), 461-9.

The near coastal areas of the landscape around Chennai, Tamil Nadu, preserve younger fluvial deposits than the ferricretes, which are of the late Neogene-Pleistocene age. Two major rivers meandering parallel to one another drain in this area. They are: the Koratallaiyar, and Cooum. The interfluves are less dynamic and preserve an older record. Satellite imagery and aerial photographs have been used in this study for understanding the large floodplain areas. Investigations from remote sensing data, borehole lithologs, and field observations in the Koratallaiyar and Cooum Basin, indicate that channel migration through cut off, overbank flooding and structural control are the most important factors controlling the floodplain structure in the study area. Many older and palaeo-levees exist in the form of ridges (2-3 m high) in the Koratallaiyar floodplain. Well-developed river terrace points to late Pleistocene-early Holocene sedimentation. Presently the river is incising in its own sediments. Organic-rich sediments and peat have been dated by radiocarbon method to understand the phases of sedimentation processes. The Koratallaiyar and the Cooum River deposits can be divided into three groups based on radiocarbon calibrated ages: 9,710-8,430 yrs BP, 5,910-5,490 yrs BP and ~900 yrs BP. Rates of net sediment accumulation calculated using these radiocarbon dates, span a period of the order 10>^>2-10³ yrs BP. Change in grain size and process of sedimentation relates to structural configuration of the basin, minor changes in winter monsoon climate and varying magnitude of flood events.

4 illus, 4 tables, 16 ref

001185   Murthy C R;Rao Y R (National Water Res Inst, , 867 Lakeshore Road, Burlington, L7R 4A6, Canada) : Circulation and turbulent diffusion processes in the great lakes. Proc Indian Natn Sci Acad-Pt A 2003, 69(5), 633-44.

Describes some aspects of the physical and dynamical processes in the coastal oceans with examples illustrated from the North American Great Lakes. North American Great Lakes with horizontal scales of hundreds of kilometers and depth scales of hundreds of metres behave much like inland seas and exhibit physical and dynamical processes characteristics of the coastal oceans. However, these characteristics are determined by the facts that the Great Lakes basins are enclosed, horizontal dimensions are larger than the vertical dimensions, and the principal source of mechanical energy is the wind. Describes the aspects of both advection and diffusion based on physical experiments. Simultaneous measurements of Lagrangian and Eulerian currents provided the mean flow properties and horizontal and vertical exchange characteristics. Dye (tracer) experiments were also conducted to obtain the diffusion of coefficients in both horizontal and vertical dimensions. It has observed an array of complexities in coastal currents that vary in magnitude, time and space. The kinetic energy of coastal currents shows a maximum at 10-12 days periodicity, which is due to large scale meteorological forcing and a secondary peak at a period of 16-18 hours due to near-inertial oscillations. Superimposed on this large scale circulation, coastal currents exhibit episodic events of shorter duration (typically 2-3 days) such as upwelling/downwelling, strong alongshore coastal jets and weaker stagnation currents interspersed with reversals. Coastal circulation features introduce a wide range of nearshore/offshore exchange processes. Alongshore exchange coefficients are typically higher than cross-shore turbulent exchange coefficients by a factor of 2-3. Vertical exchange coefficients are closely related to dynamic stability of the water column, and their values varied between 1 to 60 cm²/s.

9 illus, 1 table, 21 ref

001184   Mohanty U C;Rao P L S;Raju P V S;Bhatla R (Centre for Atmospheric Sciences, Indian Inst of Tech Delhi, Hauz Khas, New Delhi-110 016) : Study on diagnostic aspects of South Asian summer monsoon. Proc Indian Natn Sci Acad-Pt A 2003, 69(5), 505-21.

Study illustrates diagnostic aspects associated with the south Asian summer monsoon (SASM) based on large-scale budgets of kinetic energy, heat, moisture, vorticity and angular momentum. For this purpose, the National Centre for Environmental Prediction/National Centre for Atmospheric Research (NCEP/NCAR) reanalysis data for forty-two year (1958-1999) period and the European Centre for Medium Range Weather Prediction (ECMWF) data for a couple of seasons (1987 & 1988) are used. The primary objectives of the study are to comprehend the climate diagnostics and interannual variability of the summer monsoon. The SASM is characterized as the source of kinetic energy as well as vorticity, convergence of heat and moisture fluxes, and angular momentum. In the kinetic energy budget, the adiabatic generation is balanced by the frictional dissipation and horizontal flux divergence of kinetic energy. The heat budget is governed by the horizontal flux divergence of sensible heat, conversion of available potential energy to kinetic energy and diabatic heating. The persistent convergene flux of heat and moisture facilitates enhancement of diabatic heating and in turn leads to the formation of heat sources to drive monsoon circulation. In the vorticity budget, the horizontal transportation is effectively balanced by the generation of vorticity due to sub-grid scale processes and also generation due to tilting of isobaric surfaces. The angular momentum generated due to pressure torque (east-west pressure gradient) is balanced by the flux convergence of omega momentum. Further, the angular momentum budget delineates that the flux convergence of relative momentum is necessary to maintain the surface westerlies against the friction. In terms of interannual variability, energetics of the south Asian summer monsoon using the NCEP and ECMWF data sets for two contrasting monsoon seasons of 1987 and 1988 are also discussed.

9 illus, 4 tables, 32 ref

001183   Moh'D B K;Abu-Hamatteh Z S H (Natural Resources and Chemical Engineering Department, Tafila Applied University College, Al-Balqa'Applied University, P.O. Box: 26(66141), Tafila Jordan) : Mineralogy and geochemistry of Siwaqa travertine South Amman, Jordan. J Geol Soc India 2004, 64(5), 647-54.

Siwaqa Travertine occurs about 70 km south of Amman, in the vicinity of Siwaqa strike slip fault. Representative surface and subsurface samples of travertine have been analyzed by X-ray diffraction, ICP and wet chemistry to study the mineralogy and geochemistry of travertine. Data of Siwaqa travertine is compared with travertines from other localities in Jordan. Calcite is the most dominant constituent. Dolomite, quartz, kaolinite, gypsum/bassanite, and hematite are present in minor amounts. Presence of clay minerals and iron oxides have resulted in the departure of travertine from its creamy white colour. CaO with an average of 50.9% is manly attributed to carbonate minerals, particularly calcite. Relatively rich trace element content in Siwaqa travertine compared to Mujeb travertine is attributed to leaching of underlying oil shale and/or marble. Higher concentrations of some of the elements probably resulted due to diagenetic processes and syngenetic mineralization.

1 illus, 6 tables, 19 ref

001182   Melwanki M B;Seetharamappa J (Research Scholar, Department of Chemistry, Karnatak University, Dharwad 580 003) : Spectrophotometric studies on the investigation of chromium in environmental samples. Indian J envir Hlth 2003, 45(1), 25-8.

Isothipendyl hydrochloride is proposed as a sensitive and selective reagent for the rapid spectrophotometric determination of chromium (VI). The reagent instantaneously gives a red coloured species on reaction with chromium (VI) in phosphoric acid medium which exhibits maximum absorbance at 510 nm with Sandell's sensitivity of 2.28 ng cm². Beer's law is valid over the concentration range of 0.1-1.9 mg/I with an optimum concentration range of 0.2-1.7 mg/I. The method has been successfully applied to the analysis of chromium in environmental samples.

2 tables, 7 ref

001181   Krishnamurti T N;Vijaya Kumar T S V (Meterology Dep, The Florida State Univ, Tallahassee Fl 32306-4520, USA) : Suprensemble forecasts for weather and climate. Proc Indian Natn Sci Acad-Pt A 2003, 69(5), 567-83.

The improvements in forecasting heavy rains heavy rains by the multimodel/multianalysis superensemble are found to provide useful guidance in flood events. In hurricane forecasts improvements in track position forecasts of the order of 100 to 250 km were noted in one to three day forecasts. Intensity forecast for hurricanes shows only a marginal improvement. The seasonal climate forecasts show a lower performance from the member models compared to climatology, the multimodel superensemble appears to have skill somewhat above that of climatology. Also outlines areas of future work that includes a thrust on tropical cyclones of the Indian Ocean basin where the impacts would be relevant to the Indian subcontinent.

14 illus, 2 tables, 12 ref

001180   Khadkikar A S (Geology and Palaeontology Group, Agharkar Research Institute, G G Agarkar road, Pune-411 004) : Coastal aeolianite deposits: an archive of Indian monsoon rainfall and winds over the late quaternary. J Geol Soc India 2004, 64(4), 491-502.

Coastal aeolianites occur throughout the world both in the sub-tropical and extra-tropical regions and act as valuable repositories of both past climate changes due to their sensitivity to meteoric diagenesis. Palaeowind directions (northeast to north northeast) based on measurements ot these cross-beds suggest that the formative winds were the Indian summer monsoon winds. Stratigraphic and architectural analyses reveal that the coastal aeolianite deposits (Miliolite) have three Treea Rossa type soils over the past ~200 ka. This points to the fact that coastal aeolianites respond sensitively to the changing intensities of the Indian monsoon rainfall. Periods of increased rainfall led to weathering which eventually formed Terra Rossa like soils while prolonged periods of reduced rainfall but strong winds led to the formation of parabolic dunes. As strong monsoon winds are required both for precipitation and wind transport, this suggest, that the Indian summer monsoon winds were strong and intense throughout the past ~200 ka. These results validate recent results from a coupled ocean-atmosphere GCM that predict stronger summer monsoon winds during glacial periods.

8 illus, 37 ref

001179   Kalender L;Hanelci S (Firat University, Geological Engineering Department, , 32119 Elazig, Turkey) : General features of copper mineralization in the Eastern Euphrates, Keban-Elazig Area, Turkey. J Geol Soc India 2004, 64(5), 655-65.

The copper mineralization at Nalliziyaret Tepe, in Eastern Taurid region of Turkey is a typical example of porphyry-type sulphide hosted by Upper Cretaceous Keban Magmatic rocks. The latter, comprising subvolcanic rocks and plutonic rocks of syeno-monzonitic affinity, intrude Keban metamorphic rocks of Permo-Carboniferous age. Major and trace element geochemistry of the magmatic rocks suggest that these are alkaline in nature and intruded in a volcanic arc environment during late orogenic stage. The sulphide mineralization (pyrite, chalcopyrite and minor sphalerite, galena and bornite) in the form of disseminations and stock work ore veinlets occur in radial fractures of the syenite porphyry pluton. This study envisages two stages of hydrothermal wall-rock alteration during the mineralization. The first stage resulted in sodic, calcic, potassic and low sulphidic alterations but this stage accompanies the copper ore body. The second stage is mainly a sodic alteration that laterally grades into chloritic alteration zones. Fluid inclusion studies in quartz, calcite and fluorite minerals associated with mineralization indicate that the ore forming fluids contain NaCl-CaCl₂-MgCl₂-FeCl₂. The salinity and temperature of mineralization are high during the deposition of the ore minerals and decreased towards the later phase. The fluid inclusions are interpreted here as of two different origins, the early phase representing magmatic origin and the later phase may be of meteoric (shallow) origin. It is concluded here that the copper bearing fluids derived from magmatic rocks circulated through the metamorphic basement and deposited along fractures in the altered syenitic rocks.

7 illus, 3 tables, 34 ref

001178   Kale V S;Joshi V U;Hire P S (Department of Geography, University of Pune, Pune-411 007) : Palaeohydrological reconstructions based on analysis of a palaeochannel and toba-ash associated alluvial sediments in the Deccan Trap Region, India. J Geol Soc India 2004, 64(4), 481-9.

The Pleistocene-Holocene palaeohydrological and palaeoenvironmental conditions of the Deccan Trap rivers are not well-established. This is mainly on account of the limited extent of alluvial deposits and scarcity of palaeochannels to estimate former river discharges. Reports the results of recent investigations of a palaeochannel and the volcanic-ash associated alluvial materials at two sites located in the semi-arid parts of the Deccan Trap region. The palaeochannel is preserved in, and defined, by the volcanic ash. The ash is believed to be associated with the 74 ka Toba mega-eruption. The geometry of the palaeo and modern channels were determined by undertaking EDM surveys. The mean, maximum and bankfull discharges of the palaeo and modern channels were estimated on the basis of published relationships between discharge and channel dimensions. The estimates indicate a bankfull discharge of about 15-40 m³s¹ for the palaeochannel and between 600 and 900 m³s¹ for the modern channel. The estimates suggest that modern discharges are higher by about one order of magnitude. Stratigraphical studies at the sites show that the ash layer is often associated with thick black clays, referred to as fissured clays, which belong to marine isotope stage 3 and/or 4. On the basis of modern analogs it was inferred that the ash-associated fissured clays represent sediments of seasonal, low-energy wetlands. The sedimentological characteristics indicate that during and after the Toba event the monsoonal climate was drier and river discharges were depleted. This inference is also supported by estimated mean and maximum discharges passing through the Kukadi Palaeochannel. It infers that at the time of the Toba event, which occurred during marine isotope stage 5-4 transition, the monsoon discharge and rainfall were much lower than the present in the Deccan Trap region.

5 illus, 2 tables, 27 ref

001177   Kale V S;Gupta A;Singhvi A K (Department of Geography, University of Pune, Pune-411 007) : Late pleistocene-holocene palaeohydrology of monsoon Asia. J Geol Soc India 2004, 64(4), 403-17.

3 illus, 2 tables, 139 ref

001176   Juyal N;Chamyal L S;Bhandari S;Maurya D M (Department of Geology, M S University of Baroda, Vadodara-390 002) : Environmental changes during late pleistocene in the Orsang river basin, Western India. J Geol Soc India 2004, 64(4), 471-9.

Chronometric and sedimentological data generated from the exposed Quaternary sequences of the Orsang River basin indicate close correspondence between the environmental changes and fluvial aggradation. The oldest and regionally extensive fine silty-clay occurring at the base of the successions is dated to <62>97 ka suggesting prevalence of high sinuosity suspended load fluvial regime. Its stratigraphic position suggests that the deposition occurred during the enhanced southwest monsoon corresponding to the Marine Isotopic Stage-5 (MIS-5). The gravel deposits that overlie provide an age of ~60 ka indicating dominance of braided system (MIS-4) during the reduced southwest monsoon. The pluvial interstadial (MIS-3) is represented by flood plain facies that was deposited under the persistent fluvial system strengthened by enhanced southwest monsoon and assigned ages ranging between 50 and 30 ka. An extensive aeolian sand sheet that blankets the topography, is luminescence dated to 21 ka suggesting the onset of Last Glacial Maximum in the Orsang River basin.

3 illus, 1 table, 43 ref

001175   Herget j (Department of Geography, Universty of Bonn, Meckenheimer Allee 166, D-53115 Bonn, Germany) : Reconstruction of ice-dammed lake outburst floods in the Altai mountains, Siberia. J Geol Soc India 2004, 64(4), 561-74.

Seven independent approaches to estimate the pleistocene ice-dammed lake outburst floods in the Altai-Mountains were applied. Different methods are briefly presented and discussed. The peak discharge is estimated as about 10,000,000 m³s^-1. This estimate is based on three independent calculations, considering numerous locations with palaeostage indicators along the flood's pathway. Run-up sediments are found in front of the local valley obstructions. Their characteristics and their relation to giant bars nearby is considered to calculare the velocity head of the flow, which is interpreted as indicator of the mean flow velocity. Due to the dynamics of the investigaled flood, related features, such as gravel dunes and obstacle marks, provide data on unspecified stages of the decreasing flood. An attempt to estimate peak discharge by using flow competence approach failed due to missing evidence of associated macroturbulence effects. Compared with previous estimates the peak discharge calculated with several conservative assumptions seems to be smaller than expected. The new calculations are based on a significantly increased number of palaeostage indicators, which support the plausiblity of the results.

^iia9 illus, 3 tables, 44 ref

001174   Heine K (Institute fur Geographie, Universitat Regensburg, D-93040 Regensburg, Germany) : Flood reconstructions in the Namib Desert, Namibia and little ice age climatic implications: evidence from slackwater deposits and desert soil sequences. J Geol Soc India 2004, 64(4), 535-47.

Fluvial silts, accumulated in some Namib Valleys, to date are interpreted as records of reduced precipitation in the catchments. The investigations show that these fluvial silts are slackwater deposits (SWD) which document hydrologic and climatic conditions during the late Holocene that cause extreme flash floods in the valleys. It describes SWDs of some Namibian Desert valleys and present ¹⁴C dates of their ages. The youngest accumulation phase occurred during the Litle Ice Age (LIA, Ca. AD 1300 to 1850). The biggest flash floods of the LIA, in most catchments, experienced water levels in the valleys that exceeded the most extreme floods of the last 100 to 150 years. In the northwestern Namib Desert, flash floods of the LIA were more frequent and more extreme than in the central Namib Desert. This may be caused by small shifts of the tropical-temperate-troughs (TTT) in southern Africa and the southwest Indian Ocean that correlate with changes of cosmic ray intensity.

8 illus, 51 ref

001173   Hassan H;Raman S (Marine Earth and Atmospheric Sci Dep, North Carolina State Univ Raleigh, NC 27695-8208 USA) : Numerical modelling of coastal circulations near complex topography. Proc Indian Natn Sci Acad-Pt A 2003, 69(5), 615-32.

Brunei Darussalam has an equatorial climate. Sea breezes occur almost everyday. The elevated topography of the neighboring countries leads to complex wind flow patterns when combined with the coastal circulations. Transport of pollutants under these circumstances in turn becomes complex. To study the role of the coastal circulation on the long-range transport of pollutants in Brunei region, a non-hydrostatic mesoscale model (MM5) was used to simulate the flow conditions over Brunei using one-way, double nested domain. The period chosen was during the ENSO year when haze conditions were prevalent in the region. The simulated wind fields from the model were used to determine trajectories of air parcels. Observations and numerical results show that, due to strong solar heating over land, sea breeze develops along the coastline coupled with stable offshore flow aloft induced by the topography. Onshore flow persists into early night, possibly due to the larger island induced circulation. It is replaced by offshore katabatic flow as the night advances.

19 illus, 8 ref

001172   Gupta I;Bassin J;Kelkar P;Gupta A (National Environmental Engineering Research Institute, , Nehru Marg, Nagpur 440 020) : Reorganization of water distribution system of greater Jammu using computer software OPT DIS. Indian J envir Hlth 2003, 45(1), 39-48.

Water supply in old Jammu city is not evenly distributed due to undulating terrain and increase in population density. A study was undertaken to suggest measures for improvement to the distribution system. Results of analysis carried out using computer package OPT DIS developed at NEERI for optimal design of distribution system including system augmentation and reorganization measures needed for the design year 2021 have been presented. The analysis of zone 1 of the distribution network indicates that seven pipes need alteration to cater to the demand for the year 2006 and fifteen pipes need replacement for the year 2021. New pipelines (13 nos.) are to be provided in parallel to the existing pipes in Upper Reach and 28 pipes in Lower Reach to ensure the service standards of 225 lped with minimum residual head of 17 m. Efficient algorithm for augmentations of water systems comprising combination of dead-end and loop network are having much wider application in developing countries. The software OPT DIS developed at NEERI was found to be extremely powerful and user friendly for addressing such systems with varying demand pattern, peaking factor, pipe condition, water supply modes and design horizons.

4 illus, 5 tables, 4 ref

001171   Gupta A (School of Geography, University of Leeds, Leeds LS2 9JT, UK) : The Mekong river: morphology, evolution and palaeoenvironment. J Geol Soc India 2004, 64(4), 525-33.

The Mekong, the largest river in Southeast Asia, shows striking variations in channel form and behaviour along its course. It appears to link several different types of channel rather than continuing in an orderly progression. Eight different river units have been identified along the lower 2000+km of the river from the Chinese border to the sea across Southeast Asia. The exercise was carried out using satellite images, field visits, topographical maps, and various publications of the Mekong River Commission including large-scale river maps. The boundaries between such units are sharp and not gradual. They are different from each other depending on their morphological characteristics, their behaviour and whether the channel is bedrock-controlled. The Mekong flows for nearly 4000 km before being a freely-moving river with overbank flooding and course changes across the wide plain of Cambodia. Prior to that the channel is essentially structure-guided. It is a seasonal river with high flows during the southwestern monsoon and periodic floods late in the wet season. This linkage of several identifiable river units and the location of the present course of the river have not been properly explained. The estimated stream power of the Mekong in large floods seems to be very low when compared to what is required to erode a large channel in rock even along geological lineations. The opening of the South China Sea and the lowlands of Southeast Asia are associated with extrusion tectonics resulting from the Indian Plate colliding with the Eurasian Plate and building of the Himalaya Mountains from Eocene onwards. The present course of the river is likely to have been determined at least primarily from this event, and possibly also associated with stronger monsoon systems in the Early Holocene as recognised for South Asia. Morphology comparable to that of the Mekong seems to exist in several other major rivers of Southeast Asia and there could be a regional pattern, but investigation on this topic has hardly started.

6 illus, 2 tables, 18 ref

001170   Gregory K J (Department of Geography, University of Southampton, UK) : Palaeohydrology and river channel management. J Geol Soc India 2004, 64(4), 383-94.

Palaeohydrology has continued to develop during the GLOCOPH period (1991-2003) so that it is now appropriate to consider how its research contributions can relate to global change. Palaeohydrology is just one multidisciplinary research field that can make a contribution to the study of global change, achieved through deriving data, elucidating the mechanics of change; identifying spatial contrasts; assisting the coupling of global change models to hydrological models, and eventually providing new models of palaeohydrological change. Palaeohydrology can contribute to river channel management, which has now progressed from hard engineering, to ecological and thence to sustainable approaches. Inputs from paleohydrology can inform river channel hazards, although necessarily varying according to the engineering, working with the river, or sustainable approaches. Research on temporal change can provide information for river management to complement periods of continuous instrumental records. Contributions can be made from palaeohydrology for the elaboration of flow records, especially of palaeofloods; demonstration of the sensitivity of reaches and their role within a basin context; provision of hydrological and sedimentological histories to provide a temporal context; and elucidating the question of what is `natural'. It is possible to extend protocols for river channel management by a provisional protocol from palaeohydrology. Although palaeohydrology, may not readily provide analogues for future sequences it can provide insight into the scenarios and mechanisms that may occur, and offers experience that requires river management to be undertaken within the framework of a long-term perspective.

7 tables, 62 ref

001169   Gopalakrishnan S G;Rama Krishna T V B P S; Sharan M (SAIC at EMC/NCEP/NOAA, World Weather Building, , 5200 Auth Road Camp Spring, MD 20746 USA) : Some signatures of urban heat patches in southern India. Proc Indian Natn Sci Acad-Pt A 2003, 69(5), 603-14.

By 2025 it is estimated that about 80% of the world population will live in cities. In a fast developing country like India more and more vegetated suburban and rural areas are being constantly replaced by artificial surfaces that have differential thermal properties, and extensive contrasts of land surface created by such heterogeneities produces the Heat Island Effect, and consequently, the development of an urban circulation. Here it shows some evidence of "stress" in vegetation temperature index in regions of peninsular India that may partly be due to expansion of major South Indian cities of Chennai, Bangalore and Hyderabad; demonstrate using a three dimensional model the effect of these urban heat patches on regional scale meteorology and finally discuss the future scope of this preliminary study. The modelling efforts indicate that for the three specified urban heat patches, at sunset, sizes of which were grossly based on vegetation index in peninsular India as well as mean monthly variation in vegetation index around these cities, urban heat island, as indicated by closed isotherms, continue to persist late into the night time during all the three seasons, namely, pre-monsoon, monsoon and winter. It should be emphasized that the regional scale topographical features, such as the Western Ghats do not diminish the urban effects. The strongest influence is found in Chennai, which, of course, is expected due to out-growth of this city into what was suburban area in past. It appears that there is a critical patch size for a given flow field beyond which Urban circulation centre is unaltered.

8 illus, 46 ref

001168   Desai B G;Patel S J (Department of Geology, M S University of Baroda, Vadodara-390 002) : Kachchh earthquake of 2001: seismically triggered deformed structures in the intertidal sediments of Mandvi coast in the Gulf of Kachchh, Gujarat. J Geol Soc India 2004, 64(5), 637-46.

On 26 January 2001, a major earthquake of magnitude of 7.7 caused extensive damage in Kachchh and other parts of Gujarat. Mandvi coast in the Gulf of Kachchh, which is 150 km far from the epicentral zone, is also highly affected by the high magnitude seismic waves causing deformed structures in soft sodiments. These induced deformed soft sediment structures are recorded in the small lagoon adjoining beach area. The structures include sand blows, cracks, micro faulting, deformed cross-laminae, flume and pillar structures and large injection stuctures, which are attributed to intrusion spout phenomena. Abnormal behaiour of suspension feeding squillidean stomatopod, Oratosquilla striata species, was also observed. These structures are interpreted to originated by the process of fluidisation and liquefaction of cohessionless peaty subsurace layer underneath the clastic sediments. The shear stress related to earthquake acted as trigger agent.

4 illus, 1 table, 51 ref

001167   Calagari A A (Geology Department, Natural Science Faculty, Tabriz University, Tabriz 516 64, Iran) : Geology and fracture-related hypogene hydrothermal alteration and mineralization of porphyry copper deposit at Sungun , Iran. J Geol Soc India 2004, 64(5), 595-618.

The porphyry copper deposit at Sungun is located in East Azarbaidjan, NW of Iran. The magmatic suite in the Sungun area is a part of NW-SE trending Cenozoic magmatic belt of Iran. The Sungun porphyries (Oligo-Miocene) occur as stocks and dykes, and intrude a series of Oligocene dacitic breccias and tuffs and trachy-andesitic lavas, Eocene arenaceous-argillaceous rocks, and Upper Creataceous carbonate rocks. The porphyry stocks are divided into two groups: the porphyry stock I (quartz monzo-diorite) and the prophyry stock II (quartz monzonite, granodiorite, and granite). The porphyry stock II hosts the copper ores. For series of cross-cutting dykes (DK₁, DK₂, DK₃ and DK₄), ranging in composition from quartz monzo-diorite to granodiorite intruded the Sungun porphyry stocks and surrounding enclosing rocks. The whole-rock chemical analyses of the samples for major and trace elements showed that the parental magma of the Sungun porphyries formed in continental margin tectonic setting, and was mainly calc-alkaline in character. Four types of hypogene alterations are present at Sungun: potassic, potassic-phyllic, phyllic and propylitic. The potassic, potassic, potassic-phyllic, and phyllic alteration zones were principally developed in the prophyry stock II, whereas the propylitic alteration zone is chiefly restricted to the peripheral porphyry stocks I and dyke series DK₂ and DK₃. The phyllic and potassic phyllic occurred in zones where the rocks underwent severe hydro-fracturing manifested by numerous and various cross-cuting veinlets and micro-veinlets of quartz, sulphides, silicate, carbonates, and sulphates. The hypogene mineralization is characterized by the introduction of hypogen sulphides such as pyrite, chalcopyrie, molybdenite, tetrahedrite, bornite, and chalcocite. Three stages of hypogene mineralization, though continuous, were recognized: early middle and late. The early stage was contemporaneous with the development of the early-type quartz veinlets and potassic alteration. The middle stage that is the main stage of copper mineralization, was contemporaneous with the phyllic alteration. Pyrite, chalcopyrite, and molybdenite along with trace amounts of tetrahedrite, bornite, and chalcocite are also associated with this stage. The sulphides are mainly concentrated in the phyllic and potassic-phyllic zones, and their abundance gradually decreases downward toward the potassic zone. The abundance of copper-bearing hypogene sulphides gradually decreases upward towards the upper parts of the phyllic zone where pyrite is relatively abundant. Only locally small amounts of sulphides (<2 wt%) are associated with rocks that underwent propylitic alteration. The XRF and electron-probe micro-analyses data combined with microscopic evidence suggest that the alteration of ferromagnesians liberated considerable Fe which in turn acted as a major factor for the fixation of the magmatically-derived sulphur in the ore-bearing solutions. Copper and molybdenum were introduced by the hydrothermal ore-bearing fluids.

23 illus, 3 tables, 35 ref

001166   Boochabun K;Tych W;Chappeld N A;Carling P A; Lorsirirat K;Pa-Obsaeng S (The Royal Irrigation Department, , Bangkok, Thailand) : Statistical modelling of rainfall and river flow in thailand. J Geol Soc India 2004, 64(4), 503-15.

Thailand experiences severe floods and droughts that affect agriculture. New techniques, such as Data-Based-Mechanistic modelling are being developed to study rainfall and river flow to improve flood and drought alleviation policies and practices. Dynamic Harmonic Regression models are used to analyze rainfall and discharge time series across Thailand to define seasonality, trends and to forecast rainfall and discharge and their spatial distribution. Statistical patterns in the frequency of extreme rainfall and flow periods are identified with a view to improving predictions of medium and longer-term rainfall and river flow patterns. The results show temporal and spatial variation within the annual rainfall pattern in the study catchments. For example, the seasonality of the rainfall in the south is less pronounced (more equatorial). The discharge seasonal pattern shows stronger semi-annual cycles, with the weakest pattern in the south of country, whereas the strongest discharge seasonality is observed in the far north. The overall areal rainfall trend has not changed significantly over the last 20 years. Dry years can be associated with ENSO events. The discharge trend also tended to dip in ENSO years. The DHR forecasts of rainfall and river flow data for 1998-1999 using data up to 1997 have low prediction errors.

7 illus, 5 tables, 14 ref

001165   Bhatia R C;Srivastav S K (India Meteorological Dep, , Lodi Road, New Delhi-110 003) : Space-based remote sensing of ocean surface. Proc Indian Natn Sci Acad-Pt A 2003, 69(5), 645-60.

Meteorological observations over vast oceanic areas are of vital importance for a number of applications. Remote Sensing techniques using space-based platforms are the only practically feasible alternative available for obtaining the data in real-time for operational utilization. Details of observations possible from ocean surface using remote sensing technology with special emphasis on India's recent programme for ocean observations from space-based platforms. Details of Oceansat-I Satellite payloads with possible meteorological applications, explored recently, are presented. In particular the Passive Microwave based observations obtained from the microwave radiometer onboard IRS-P4 have been found to be useful for monitoring onset on monsoon and forecasting heavy rainfal during the monsoon along the west coast of India.

6 illus, 2 tables, 16 ref

001164   Baker V R (Department of Hydrology and Water Resources, University of Arizona, Tucson, AZ 85721-0011, USA) : Palaeofloods and global change. J Geol Soc India 2004, 64(4), 395-401.

A great weakness of various international scientific initiatives in global change, earth-system science, and related hydrological assessment of flood hazards is their overemphasis on prediction from idealized conceptual models. The latter are abstract constructs made possible by rapidly increasing computer power but predicated upon often unverified and sometimes unverifiable assumptions. It is now realized that abrupt climate change extreme events pose more of a global change hazard than do the mean climate phenomena predicted by global climate models (GCMs). For 20 years there has been overemphasis on developing these models as the principal tool for dealing with threats to habitability of the planet. In constrast to unverified predictions of the future given by GCMs, palaeoflood data provide evidence of real-work cataclysms that people can understand sufficiently to alter their perceptions of hazards, thereby stimulating appropriate action toward mitigation. This issue is particularly important in the world's tropical monsoon areas, which are prone to especially extreme floods and high variability in their magnitude and frequency. These areas, which are inhabited by half of the Earth's human population, also have excellent sources of palaeoflood information, which comprise a natural archive that can appropriately stimulate productive hazard reduction.

2 illus, 31 ref

001163   Bacon D P etal (Center for Atmospheric Physics, Sci Applications International Corporation, 1710 SAIC Drive, McLean, VA 22102, USA) : Dynamically adapting unstructured triangular grids: a new paradigm for geophysical fluid dynamics modelling. Proc Indian Natn Sci Acad-Pt A 2003, 69(5), 457-71.

Two primary numerical methodologies that have been used for modelling the atmosphere and the ocean have been spectral methods for global modelling and structured rectilinear grids for regional modelling. In the last few years, a new paradigm for atmospheric and oceanic simulation has emerged: adaptive, unstructured, triangular grids. This paradigm has the advantage of tremendous flexibility in providing high resolution where required by either static physical properties (terrain elevation, coastlines, land use) or the evolving dynamical situation. The first application of this paradigm was the Operational Multiscale Environment model with Grid Adaptivity (OMEGA), an atmospheric simulation and forecasting tool; a more recent application of this paradigm is the more recently developed Multiscale Ocean Simulation System (MOSS). OMEGA with its embedded Atmospheric Dispersion Model (ADM) is a new atmospheric simulation system for real-time hazard prediction, conceived out of a need to advance the state-of-the-art in numerical weather prediction in order to improve the capability to predict the transport and diffusion of hazardous releases. MOSS is a nascent implementation of a similar grid structure and numerical algorithm to the simulation of ocean circulation. The purpose of this paper is to provide description of this new paradigm and to present its use in atmospheric and oceanic simulation.

14 illus, 2 tables, 40 ref

000204   Wahi R;Dubey S;Maski K;Jain S;Vijay S;Vijay S K;Gwal A K (Space Science Laboratory, Dep of Electronics, Barkatullah Univ, Bhopal-462 026) : Magnetic storm and solar flux effects on IEC in American zone. Indian J Phys-Pt B 2004, 78(2), 233-8.

The variation of ionospheric electron content (IEC), obtained by Faraday rotation measurements of 136 MHz transmissions at Palehua (20.7°N, 254.7°E) and Anchorage (61.2°N, 210.1°E) have been studied during magnetic storms for the low solar activity period 1984. It has been observed that the variations of IEC occur in both positive and negative phase of magnetic storm for all the three location. They do not bear any clar relationship either with the magnitude of the geomagnetic storm or with the main phase onset (MPO) of the storm. Often variations of IEC are observed before MPO and its shows maximum variation at low latitude (Palehua) while this is less pronounced at mid latitude (Boulder) and high latitude (Anchorage). Effect of Sa (solar flux) on maximum IEC (IEC_max, shows the increase of IEC_max with respect to Sa at all three stations. This increase in IEC_max is more pronounced during the equioxial months.

4 illus, 1 table, 20 ref

000203   Varghese T;Balakrishna K M;Siddappa K (Dep of Physics, Nirmala College, Muvattupuzha, Kerala 686 661) : Electron momentum distribution and compton profiles of tin. Indian J Phys-Pt B 2003, 77(6), 631-4.

The Compton profile of Sn has been measured using a HPGe photon detector. The target atoms were exited by means by 59.54 ke V gamma rays from Am-241 radioactive source of strength of 300 mCi. Elemental foil of uniform aerial density and purity better than 99.9% was used as target. The data was recorded and analyzed using a 4K multichannel analyzer. The experimental data was corrected for instrumental resolution effects, sample absorption and energy dependence of the differential Compton cross-section. The Compton profiles measured in the present work for Sn constitute the first experimental report for 59.54 ke V gamma rays scattered at 165°. The results are compared with theoretical Hartree-Fock free-atom profiles.

2 illus, 1 table, 16 ref

000202   Unnikrishnan K;Venugopal C (School of Pure and Applied Physics, Mahatma Gandhi Univ, Priyadarshini Hills, Kottayam-686 560) : Latitudinal variations of strength of ionospheric response and its correlatoin with intensity of magnetic storms. Indian J Phys-Pt B 2004, 78(1), 47-53.

A study has been made to investigate the latitudinal variations of the strength of the ionspheric response to positive and negative weak as well as major magnetic storms by considering low (Ramey), mid (Sagamore Hill) and high (Goose Bay) lattitude stations duirng the year 1980-81. The nature of the correlation that exists between the strength of the response and intensity of positive and negative magnetic storms at various latitude has also been checked. In the case of weak and major positive storms, the lowest strengths of response are shown respectively by the mid and high latitude station, while the highest strength of response, for both categories of storms, is shown by the low latitude station. For weak and major negative storms the lowest strengths of response are again show respectively by the mid and high latitude stations; in contrast, the highest strengths are exihibited respectively by the high and mid latitude stations. The strength of the response duirng major positive storms, in general increase with decreasing latitude. A positive correlation was found to exist between the strength of the response and the intensity of storms during weak and major positive storms for the low latitude station, Ramey. A similar trend was also seen for low and mid lattitude stations duirng major negative storms. However, in the case of weak negative storms, a negative correlation was found to exist between the strength of the response and the intensity of storms for all the three latitudes, contrary to the previous stuides for low latitudes during negative storms. Also, a negative correlation is observed between the intensity and time delay for maximum ionopheric response, in the case of positive weak stroms for low latitude and negative weak storms for high latitude.

5 illus, 28 ref

000201   Singh D K;Das I M L;Singh R P (Indian Institute of Tropical Meteorology, , Pune 411 008) : Energy and amplification of whistler mode wave. Indian J Phys-Pt B 2004, 78(1), 31-8.

Parallel resonance energy and wave growth/damping of the electrons in the magnetosphere at various frequencies for different L-values have been computed for whistler mode wave in the presence of thermal velocity and parallel electric field. The resonance energy of the electron decreases with wave frequency as well as with L-value. The wave growth/damping depends on the nature to the dcelectric field present in the Earth's magnetosphere.

4 illus, 21 ref

000200   Singh A K;Singh R P (Atomospheric Research Laboratory, Dep of Physics, Banaras Hindu Univ, Varanasi 221 005) : Space weather- causes cosequences and predictions. Indian J Phys-Pt B 2003, 77(6), 611-16.

Space-weather defines variation in the plasma speed and density, solar magnetic field and radiation density in the near Earth-space environment and consequences of those variation. It is scientifically interesting and challenging research field that has significant economic importance all over the world. Adverse changes in the near Earth-space environment can diminish the performance and reliability of both spacecraft and ground-based systems. Describe the cause and effects of space weather. Some means for space-weather predictions are also suggested.

1 table, 30 ref

000199   Sharma H;Kiran Kumari;Pandey S K (Univ Dep of Physics, Veer Kunwar Singh Univ, Arrah 802 301) : Photoionization of potassium. Indian J Phys-Pt B 2003, 77(6), 635-8.

An analytic atomic independent particle model (IPM) potential is used to investigate the ground state photoionization cross section of the 4s electron of atomic potassium as a function of incident photon wavelength in the dipole length approximation. The spin-orbit interaction is included in the model potential and effects of core polarization have explicitly been considered. The predicted photoionization cross sections are in better agreement with experiments than those of earlier calculations from threshold up to abount 2600 Armstrong.

1 illus, 18 ref

000198   S K Kar;Bhattacharya;Yuei-An Liou (Centre for Space and Remote Sensing Research, National Central Univ, Chung-Le, Taiwan) : Solar effects on terrestrial radio communication distrubances and associated tropospheric and ionospheric variations. Indian J Phys-Pt B 2004, 78(2), 151-63.

The present state of kowledge on solar effects on terrestrial radio communication disturbances and associated atmospheric variations has been reviewed. As outline is given on the electrial behaviour of clouds with an emphasis on the thunderstrom activity, electrical discharges above the inside a cloud, global atmospheric variation and atmospheric electricity in relation to solar UV-variability. Effects of geomagnetic storms in the lower ionosphere and troposphere have been considered at length. Finally, the scope for furture investigation in indicated.

2 illus, 93 ref

000197   Ojokoh A O;Adebayo A;Akharaiyi F C (Microbiology Dep, Federal University of Technology, Akure, Nigeria) : Bacteriological and chemical analysis of some ground water supplies in Kuyoro, Akure. Oriental J Chem 2002, 18(3), 433-8.

Bacteriologic and chemical analysis of some ground water supplies in Kuyoro were conducted. All 10 samples tested were considered unfit for human consumption with total coliform counts ranging from 36 to 91 cells/110 ml. The total bacteria counts for all samples ranged from 3.34 x 10³ cfu/ml to 7.20 x 10³ cfu/ml and Staphylococcus aureus from 0.34 x 10⁴ cfu/ml to 2.29 x 10⁴ cfu/ml. The bacteria isolated was Escherichia coli, Shigella, Bacillus cereus, Salmonella typhi, Micrococcus luteus, Staphyloccus aureus and Pseudomonas aeruginosa. The concentration of the trace elements assayed for were higher than the WHO standard for potable water.

3 illus, 2 tables, 21 ref

000196   Nagaraju A;Karimula S;Killham K (Geology Dep, S V Univ, Tirupati-517 502) : Physical properties of termite mounds: a case study from the mangampeta barite mining area of Andhra Pradesh, India. Indian J Ecol 2004, 31(1), 14-6.

The physical and textural properties of soils of termite mounds from the mangampeta barite mining area of Andhra Pradesh were studied and compared with adjacent termite free soils. Termite mounds contain lower amounts of sand and higher amount of silt and clay than the adjacent surface soils. The mounds contain increased organic matter, and have lower bulk density. Grain size parameters. viz mean, median, sorting, skewness and kurtosis reveal that mean and median values are higher in termite soils. Generally, sorting, skewness and kurtosis values are lower in termite soils than the surface soils. Further, a high degree of positive correlation is noticed in both termite soils and its adjacent surface soils.

1 illus, a table, 17 ref

000195   Mandal G;Pradeep Kumar P (Physics Dep, Pune Univ, Pune 411 007) : Laboratory studies on the effect of external electric fields and discharges on charge transfer during ice-hail collision. Indian J Phys-Pt B 2004, 78(1), 39-45.

Laboratory experiments have been carried out in a walk-in cold room to investigate the effect of uniform and radial electric fields and electrical discharges on charge transfer during collision between ice crystal and groupel (soft-hail). It has been found from these experiments that the average size of crystal decreases with the increasing electric field. However, when discharges are applied to the cloud the ice crystal size is larger. It is also seen that the charge transfer value is always high for low electric field and less for high electric field. The charge transfer values after a discharge has taken place in the cloud are higher. It is also observed that the ratio of ice crystal to water droplet is an important parameter for thunderstorm electrification. If the ratio is high then charge transfer values are leass and if the ratio (<60>1) is small, charge transfer values are more.

14 illus, 19 ref

000194   Dubey S;Wahi R;Maski K;Vijay S K;Gwal A K (Space Science Laboratory, Dep of Electronics, Barkatullah Univ, Bhopal-462 026) : Day-to day variability of IEC at mid latitude during sunspot minimum. Indian J Phys-Pt B 2004, 78(2), 229-32.

Study of day-to-day variability has been carried out by using hourly values of Ionospheric electron content (IEC) for two mid latitude locations, Boulder and Sagamore Hill during activity (1985-1986). Both the locations show the maximum (30-40%) variability during evening and nighttime while minimum (10-20%) is seen during daytime. Variability is higher duirng equinox (1985) and summer (1986) at Boulder and during winter (1985) and equinox (1986) at Sagmore Hill. From a correlative study of variability in IEC with possible causative factor such as sunspot activity, magnetic activity and solar activity, it is seen that the magnetic activity has appreciable association with the variability of IEC. Also compare the variability during quiet days and disturbed days.

6 illus, 14 ref

000193   Barghouthi I A;Qatanani N A;Abu Issa M (Dep of Physics, Al-Quds Univ, Abu Dies Jerusalem Palestine) : Toroidal distributions in the polar wind plasma. Indian J Phys-Pt B 2003, 77(6), 621-4.

The energization of charged particles, due to interaction with electromgnetic turbulence, has an important influence on the plasma outflow in space. The effect of wave-particle interaction (WPI) on O⁺ and H⁺ velocity distribution in the polar wind was investigated by using Monte Carlo method. The Monte Carlo simulation included the effect of WPI, gravity, polarization electrostatic field, and the divergence of geomagnetic field within the simulation tube (1.7-10 earth radii, Re) as the ions are heated due to WPI and move to higher altitude, the ion's Larmor radius a_L may become comparable to the perpendicular wave length λ_⊥ of the electromagnetic turbulence. As the ratio a_L/λ_⊥ becomes <62>^<126> 1, the quasi-linear perpendicular diffusion coefficient becomes velocity dependent, the heating rate becomes self-limited and the ion ditribution displays tortoidal features. This result is consistent with observations O⁺ toroidal distribution in the auroral region.

2 illus, 19 ref

014635   Rao L A K;Ansari Z R;Khan S;Sadique M;Yusuf A (Geology Dep, Aligarh Muslim Univ, Aligarh-202 002) : Geomorphologial studies in parts of Agra district, U.P., using remote sensing and GIS techniques. Ultra Scient phys Sci 2010, 22(1), 147-54.

In the present study an attempt has been made to delineate and characterized various geomorphic unit in part of the Yamuna river basin, around Etmadpur area of Agra district, Uttar Pradesh. The drainage, contour and delineated geological units have been overlaid on IRS-1D-LISS-III imagery (bands 2,3 and 4) to delineate and characterize different geomorphic units. The information generated from the satellite data in the form of vector layers has been used in GIS to generate geomorohological map of the study area. The various geoinorphological units viz; ravinous land, sand bar, younger alluvium, paleochannel, older alluvium, recent flood plain, older undulating surface have been delineated. The study area is characterized by alluvium (an admixture of gravel, sand, silt and clay) of the Quaternary age deposited over the rocks belonging to the Vindhyan Supergroup. The present study demonstrates that IRS-1D-LISS-III data in conjunction with drainage and contour parameters enable a detailed evaluation of various geomorphological units in order to utilize for evaluation and management of natural resources.

ref

014634   Muthukumarasamy R;Neelakantan R;Mukesh M V; Tamilselvi M;Yuvaraj S (Earth Sciences, Annamalai Univ, Annamalainagar-608 002) : Identification of groundwater potential zones using remote sensing and GIS in Salem taluk, Tamilnadu (India). Ultra Scient phys Sci 2010, 22(2), 311-22.

The aim of this study is to investigate the groundwater potential zones available for domestic and agriculture in Salem Taluk, Tamilnadu. Remote sensing data and geographic information system were utilized to locate potential zones for groundwater in Salem Taluk. Various maps (i.e., base, hydro geomorphological, geological, lineament, drainage, slope, land use/land cover and groundwater prospect zones) were prepared using the LANDSAT MSS data along with the existing maps. Based on the analysis, the groundwater availability zones of the study area evaluated and demarcated (i.e.) high groundwater potential, moderate groundwater potential and low ground water potential zones based on the added weightages values. The weightages is assigned based on the lithology, lineament density and geomorphology as higher ranks, where as slope, drainage density and landuse/ land cover as lower ranks. Similarly, various weightages were assigned to the individual sub variables of each thematic data, G1S layer were generated and integrated using overlay functions to identify and demarcate the groundwater potential zones. Based on the weightages the area having highest value more 202 is buffered as high groundwater potential zone, value between 149-201 as moderately groundwater potential zone and value less than 148 as low groundwater potential zones. It is concluded that the majority of area covered in high groundwater potential zones and priority wise listed out as Veerapandi, Panamarathupatti, Ayothiyapattanam and Salem Town.

4 illus, 3 tables, 12 ref

014633   Gupta R D;Arora S;Gupta G D;Sumberia N M (NO, SKUAST, Jammu, Email: aroraspau@yahoo.co.in) : Soil physical variability in relation to soil erodibility under different land uses in foothills of Siwaliks in N-W India. Trop Ecol 2010, 51(2), 183-97.

Physical properties of some soils from foothills of Siwaliks of Jammu, Jammu and Kashmir State were studied. Clay content was the highest in soils of forest profiles, followed by those under cultivated unmanaged and well-managed profiles, and least in soils of barren land profiles. Soils of barren lands showed the highest values of bulk density (1.47 to 1.60 g cm^-3), followed by cultivated unmanaged (1.46 to 1.58 g cm^-3), cultivated well-managed lands (1.34 to 1.54 g cm^-3), and least in those of forest lands (1.32 to 1.52 g cm^-3). The values of particle density decreased in the order: barren lands (2.57 to 2.68 g cm^-3) > cultivated unmanaged (2.52 to 2.67 g cm^-3) <62> cultivated well-managed (2.44 to 2.62 g cm^-3) <62> forest lands (2.38 to 2.62 g cm^-3). Soils of forest lands had generally higher values of pore space (41.4 to 47.2%) followed by cultivated well-managed lands (41.4 to 45.1%), barren (40.1 to 43.4%) and unmanaged cultivated lands (40.0 to 43.2%). Water holding capacity (%) ranged from 21.9 to 32.2, 30.5 to 40.5, 35.4 to 47.5 and 35.3 to 47.3 in soils of barren, cultivated unmanaged, cultivated well managed and forest lands, respectively. Soils of forest lands showed highest values of moisture equivalent (23.4%) and lowest in those of barren lands (15.7%), while there was not much difference in the moisture equivalent values of soils belonging to cultivated unmanaged (21.5%) and cultivated well-managed (22.9%) lands. Erosion and dispersion ratio were positively and significantly correlated with particle and bulk density. Water holding capacity and moisture equivalents were positively related to organic carbon content, and negatively related to erosion and dispersion ratio.

1 illus, 6 tables, 33 ref

014632   Ernest Raj P;Devara P C S;Saha S K;Dani K K; Maheskumar R S (NO, Indian Institute of Tropical Meteorology, Dr. Bhabha Road, Pune-411 004, Email: ernest@tropmet.res.in) : Spatio-temporal variations in aerosol properties over the Deccan plateau region, India. Pollut Res 2009, 28(4), 547-53.

Multi-wavelength sun photometric measurements of atmospheric aerosols, ozone and precipitable water have been made as part of the Indian Space Research Organization's (ISRO) Land Campaign Experiment-2004 over the Deccan Plateau region in India encompassing the geographical region 73° to 79° E longitude and 15° to 19° N latitude. Aerosol characteristics showed considerable spatial and temporal variability. Column integrated aerosol optical depth in the region varied between 0.3 and 0.6. Aerosol size distributions in this region showed both mono-modal and bi-modal nature. Aerosol radiative forcing estimates showed a cooling effect in the surface layers with a negative forcing in the range 12 - 53 W/m². Total column ozone measured by the ground-based technique varied from 237 to 265 DU and these values agreed very well with those measured by satellite.

5 illus, 1 table, 12 ref

014631   Dutta D;Sarma D K;Konwar M;Sharma S; Viswanathan G;Gairola R M;Das J;Kannan B A M;Venkateswaralu S (Physics Dep, Kohima Science College, Kohima, Nagaland-797 002, Email: sanjay_sharma11@hotmail.com) : Nowcasting of yes/no rain situations at a station using soft computing technique to the radar imagery. Indian J Radio Space Phys 2010, 39(2), 92-102.

A soft computing model for nowcasting of Yes/No rain situations, with a lead time of 2 h, is developed over DWR station at Satish Dhawan Space Centre (SDSD), Shriharikota (13.66°N, 80.23°E) using Doppler weather radar (DWR) reflectivity imageries. Primarily, precipitating systems of mesoscale, i.e. meso-gamma (2-20 km), meso-beta (20-200 km) and meso-alpha (200-2000 km) are considered for the present study. The main components of soft computing approach are: analysis of two-dimensional reflectivity imageries from DWR and utilization of artificial neural network (ANN) for training of input/output data. About 15 input and one output parameters are extracted from radar imageries. The image analysis and training of ANN are carried out on MATLAB platform. After training of ANN, 91 and 77% results are matched with the observed values for No rain and Yes rain situations, respectively. The probability of detection (POD) for the nowcasting of Yes/No rain situations is found to be 0.84. The significant improvement in the nowcasting of Yes/No rain situations is observed by the developed methodology as compared to linear multivariable regression method. The POD of Yes/No rain for other two locations, namely Chennai (12.99°N, 80.18°E) and Tiruvallur (13.09°N, 79.57°E) are found to be 0.81 and 0.77, respectively. Overall, reasonably good results are obtained by the newly developed soft computing model.

7 illus, 6 tables, 31 ref

014630   Dushiyanthan C;Jeyavel Raja Kumar T;Manoharan K (Earth Sciences Dep, Annamalai Univ, Annamalai Nagar-608 002, Email: tjeyavel@refiffmail.com) : Identification of shallow fresh water zone using electrical resistivity technique in a sedimentary terrain of part of Bhuvanagiri block, Chidambaram taluk, Cuddalore district, Southern India. Ultra Scient phys Sci 2010, 22(2), 239-44.

In this study, 4 Vertical Electrical Soundings were carried out at different locations of part of Bhuvanagiri block, Chidambaram Taluk to understand the shallow fresh water zones. Geologically it comprises with charnockite and magmatic gneisses as archean basement, sedimentary rocks of cretaceous and Mio-Pliocene with alluvium. The field resistivity data were interpreted with ipi2win software. The overall resistivity and layer thickness are varied from 1.66 ohm m to 18 ohm m and 0.9m to 53.28m respectively. The interpretation results and the subsurface lithounits are engorging VES number 1 and 4 are favorable for shallow groundwater development.

2 illus, 1 table, 9 ref

013489   Yadav R;Banerjee T;Srivastava R K (Environmental Sciences Dep, G.B. Pant Agriculture and Technology Univ, Pantanagar-263 145) : Role of organic adsorbents in removal of arsenic (III) and chromium (VI). Pollut Res 2009, 28(2), 251-6.

Removal of Arsenic (As-Ill) and Chromium (Cr-VI) from their aqueous solutions of different concentration have been done in present investigation by using carbonized organic waste material. Agro-based paddy stem and cow dung were used as adsorbents and compared with activated charcoal to determine the most efficient absorbent. The results reveal that highest removal efficiency for Chromium (VI) was with paddy stem absorbent (97%) at their 0.5 mg/L solution with 40 gm/L absorbent dose at pH 2.0 and 4 hr retention time. In case of Arsenic (III), 88.3% removal efficiency was observed with 0.5 mg/μ solution at pH 7.0 and 4 hr retention time at same absorbent dose.

2 illus, 2 tables, 5 ref

013488   Vinod Kumar;Satya Kumar M;Thakur Prasad; Kamble S G (NO, Meteorological Office, C.S.I. Airport, Mumbai, Email: vinod.kumar2@imd.gov.in) : Forecasting low level vertical wind shear over Chhatrapati Shivaji international (C.S.I.) airport Mumbai. Mausam 2010, 61(3), 401-6.

Whenever surface wind is reported ≥ 15knots (including gusts), with precipitation, Low Level Vertical Wind Shear can be forecast below 1000 ft. During dry weather, if there is a difference of 9 knots between surface and 500 ft. winds and any two consecutive level winds below 5000 ft., Low Level Vertical Wind Shear can be forecast.

3 tables, 11 ref