010297   Jha V C (Geography Dep, Visva Bharati Univ, Santiniketan, West Bengal) : Denudational processes and landform characteristics in the laterites of Birbhum district, West Bengal, India. Trans Inst Indian Geogr 2005, 27(1), 19-29.

Laterite occupies large areas in the western and south-western parts of Birbhum District, West Bengal, India. The tract lies immediately to the east of Rajmahal Trap country and Santhal Parganas in Jharkhand State, India, and it is very likely that thick masses of laterite, formerly developed in association with trap rocks in the later area, were subsequently denuded and redeposited in parts of Birbhum District in Pliocene-Pleistocene times. A study of various profiles in gullies and valley walls in streams reveals that the laterites of Birbhum District are secondary in origin. Reconstruction of the deposited lateritic material has resulted in the development of only partly mature profile. The various horizon of the profile, namely pisolitic, massive, concretionary and pallid zone with kaolinitic fines at the base, are sill imperfectly developed and show a lot of disturbances. The massive laterite with a thin pisolitic layer at the top occupies the highest parts of the lateritic plateaus. This original surface has subsequently broken by springs and gullies, weaving their way from two trunk streams, the Ajai and the Kopai, towards the interior of the lateritic plateaus. Occurrence of the two watertables in the laterite, one perched above the massive laterite and the other lying above the kaolinitic horizon, has not only helped in spring development but also in the break-up of lateritic plalteaus into ridges and flat-bottom valleys.

2 illus, 1 table, 9 ref

010296   Fulekar M H (Life Sci Dep, Univ of Mumbai Envir Biotechnol Lab Sch of Life Sci, Kalina, Santacruz (E), Mumbai-400 098) : Climate chage - a threat to environment. Indian J envir Prot 2005, 25(8), 718-26.

1 illus, 3 tables, 10 ref

010295   Chattopadhyay S (NO, , ) : Tsunami at Havelock. Sci Cult 2005, 71(1-2), 11-12.

^ssc

010294   Chabak S K;Sharma P K (NO, Wadia Inst of Himlayan Geol, Dehra Dun, Email: chabaksundeep@rediffmail.com) : Finite difference scheme and analysis of boundary conditions for wave propagation in non-homogeneous layered medium. Himalayan Geol 2005, 26(2), 381-6.

Various numerical schemes have been applied for solution of wave propagation in seismology. Herein finite difference scheme and analysis of boundary conditions for one-dimensional wave propagation is presented in case of non-homogeneous layered medium. The method used is of special interest since it uses wave equation in its inhomogeneous formulation for the purpose of discretization. Effects of free to free surface boundary condition and free to transparent boundary condition are analyzed. Numerical results for wave propagation at different time levels are obtained and presented in pictorial form. Present scheme is also applied on a regional crustal model of Himalayan region.

6 illus, 11 ref

010293   Amanullah S;Sundaram A;Lakshmi Narayanan E S (Future Studeis Dep, Madurai Kamaraj Univ, Madurai-625 021) : Fuzzy set theory application in meteorology - rainfall modelling. Indian J envir Prot 2005, 25(8), 673-9.

The application of fuzzy set theory include explorations within psychology and cognitive science of cncept formation and manipulation memory and learning, as welll as studies in the fields of economics, ecology, meteorology and others. Gives a brief overview of a major area of application in meteorology along with sample specific illustrative example in Cumbum Valley. Cumbum Valley is the one of the many composite valleys in the eastern offshoots of Western Ghats, Theni District, Tamil Nadu. This particular application focuses on an understanding of Climatological changes based on the examination of statistical records of annual rainfall value collected at Uthamapalayam station during the year 1970 through 2000. They can be analysed mathematically by postulating a process and then examining the exact point of change between draught and wet periods, how they can be predicted with a high degree of accuracy.

3 tables

008922   Yadav R P;Aggarwal R K;Bhattacharyya P;Bansal R C (Cent Soil and Wat Conservation Res and Training Inst, Res Cent, Sector-27 A, Madhya Marg, Chandigarh-160 019) : Infiltration haracteristics of different aspects and topographical locations of hilly watershed in Shivalik-lower Himalayan region in India. Indian J Soil Conserv 2005, 33(1), 44-8.

Infiltration characteristics in different aspects and topographic landscape in a 20 ha hilly watershed in Shivalik-lower Himalayan region in India were studied to investigate the long-term effect of soil and water conservation measures. Litter deposition, soil texture, organic carbon and clay content of soils were also measured to know the correlation between these soil properties with infiltration. Steady state infiltration rates gradually decreased from upper to lower reaches. Very slow to slow steady state infiltration rates (0.11 and 0.14 cm hr^-1, respectively) were observed in lower reaches of east and north facing slopes. Cumulative infiltrations were also low (0.61 to 5.2 cm) in east and north facing slopes than that of west and south facing slopes (2.43 to 24.68 cm). Significant negative exponential correlation was found between litter deposition and infiltration rate.

2 illus, 2 tables, 14 ref

008921   Verma M P;Rastogi R A (NO, KVK, Gorakhpur, Uttar Pradesh) : Liner reservoir model of Chaukhutia watershed. Indian J Soil Conserv 2005, 33(1), 18-21.

Rainfall runoff process is non-linear and hydrodynamic with spatially distributed input and outputs. The complexity of rainfall runoff process and the absence of data with which to describe in detail the character of heterogeneous watersheds and of spatially distributed inputs, simulation of the rainfall process is generally based on concept of conceptual models. Such model contains parameters that must be estimated and models vary in range of runoff situations. Due to complexity of the hydrologic process the conceptual or time area histogram model was applied on Chaukhutia watershed for the development of hydrography through routing the series of linear reservoir model. The coefficient of efficiency of the model was found to be very high (0.8370) which shows that the model adaptable for the watershed DRH development.

5 illus, 2 tables, 5 ref

008920   Veeraswamy K;Raval U (NO, Natn Geophys Res Inst, Hyderabad-500 007, Email: kv_swamy@yahoo.com) : Remobilization of the palaeoconvergent corridors hidden under the Deccan trap cover and some major stable continental region earthquakes. Curr Sci 2005, 89(3), 522-30.

Intraplate seismicity over the Indian region seems to be highly correlated with the reactivated mobile belts - which, in turn, represent tectonic boundaries (TBs) or palaeoorogenic corridors - as evidenced from the fact that during the past 200 years most of the large earthquakes (M 6) over the subcontinent have occurred in the region strongly influenced by the Deccan trap (DT) eruption, Reunion plume activity and rifting during the Cretaceous and Tertiary periods. In this context, highly destructive Koyna and Latur earthquake regions, however, seem enigmatic because of being situated over the stable Indian shield. The study examines and compares the results of some recent deep geophysical probings (including magnetotelluric, deep seismic sounding, teleseismic tomography, gravity and magnetic surveys) over both exposed parts of the Greater Dharwar Terrain (GDT) and its northern part hidden under the DT cover. This allows delineation of the northward extensions of the TBs of the GDT under the Deccan flood basaltic layer, and suggests that the Koyna and Latur regions may also be parts of the weak tectonic corridors along which different domains of the GDT (for example Western and Eastern Dharwar cratons, etc.) have accreted. It implies that parts of even the late Archaean TBs may also get reactivated if subjected to intense thermotectonic event (e.g. flood basaltic eruption). Thus like other intraplate earthquakes, those at Koyna and Latur too appear to be associated with reactivated TBs.

7 illus, 1 table, 68 ref

008919   Tripathy N R;Srivastava H B (Dep of Geol, Banaras Hindu Univ, Varanasi-221 005) : Mesoscopic ductile shear zones from the Main Central Thrust zone of Bhagirathi Valley, Garhwal higher Himalaya. Curr Sci 2005, 88(5), 815-21.

Mesoscopic ductile shear zones are well developed in the crystalline rocks of the Main Central Thrust (MCT) zone of Bhagirathi valley. Ductile and brittle-ductile shear zones are, dominantly observed and exhibit both sinistral and dextral sense of sear. Detailed analysis reveals that NE-striking sinistral and NW-strikmg dextral shear zones form a conjugate pair. The bisectors of preferred orientations of these two sets of shear zones indicate that they developed in response to NNE-SSW horizontal compression synchronous to the translation of the MCT, which took place during the northward movement of the Indian Plate. Strain analysis reveals that the mesoscopic ductile shear zones developed in response to very high strain, in a narrow zone, which even deformed the internal fabrics of the rocks. The study of quartz c-axis fabrics in mesoscopic shear zones demonstrates that a single girdle pattern of quartz developed at the shear zone boundary and became prominent in the centre of the shear zone with increase in shear strain.

7 illus, 2 tables, 22 ref

008918   Tirkey N;Biradar R S;Pikle M;Charatkar S (NO, Cent Inst of Fish Educ, Versova, Mumbai-400 061, Email: rbiradar@cife.bom.nic.in) : Study on shoreline changes of Mumbai coast using remote sensing and GIS. J Indian Soc Remote Sens 2005, 33(1), 85-92.

2 illus, 1 table, 15 ref

008917   Suman B L (NO, Indian Grassland and Fodder Res Inst, Jhansi-284 003) : Use of forage grasses and amendments to improve salt-affected soils for rice cultivation. Indian J Soil Conserv 2005, 33(1), 49-51.

Investigation was carried out to work out the gypsum requirement of salt-affected soils in comparison to Usar Tod Masala (UTM) and prilled urea fertilizer for different forage grasses during 1997-98 to 1999-2000. There was establishment of grasses within two years with the traditional urea fertilizer and with no addition of organic or chemical amendment. However, grasses establishment was more than 95% when gypsum as well as UTM were applied as source of amendment. Application of UTM as well as gypsum increased the green biomass production by 50 % over sole urea fertiliser application. Brachiaria mutica produced maximum green (63.75 t ha^-1) as well as dry (12.97 t ha^-1) biomass in comparison to Leptochloa fusca (42.65 green and 11.94 t ha^-1 dry fodder), Setaria sphacelata (41.4 green and 10.10 t ha^-1 dry fodder), Chloris gayana (34.55 green and 7.59 t ha^-1 dry fodder) Sorghum sudanensis (22.55 green and 5.85 t ha^-1 dry fodder) and Panicum maximum (16.9 green and 4.05 t ha^-1 dry fodder) in two years of cultivation. The application of amendments for reclamation of salt-affected soils and residual effects of forage grasses increased the grain yield of rice by 70 %, 55 % and 14% due to gypsum, UTM and prilled urea application, respectively over control. Similar trend in the productivity of straw yield was observed due to application of such chemical amendments.

4 tables, 4 ref

008916   Sukhija B S;Reddy D V;Nagabhushanam P; Nandakumar M V (NO, Natn Geophys Res Inst, Hyderabad-500 007, Email: bssngri@rediffmail.com) : Efficacy of percolation ponds as artificial recharge structures and the controlling factors. J Geol Soc India 2005, 66(1), 95-104.

Hard rock aquifers of southern and western India, receive less than 10% precipitation as natural recharge, and are witnessing over-exploitation. Consequently measures are being adopted to augment groundwater resources artificially. Percolation ponds or tanks, the most popular artificial recharge structures in India, are constructed across monsoon streams for the above purpose. However, no detailed study was carried out to evaluate their performance in different hydrogeological environs. The paper reports the efficacy of percolation ponds, situated in different geological terrains evaluated using chloride mass balance method. Depending on the location of the percolation tanks, varied percolation fractions (of impounded water) were obtained; Basalts: 0.20-0.30, Granite-gneisses: 0.30-0.45, and Sandstones: 0.60, depending on the transmission properties of rocks. In addition, soil characteristics and ambient hydrogeological regime of the area are important factors controlling the efficacy of a percolation tank.

5 illus, 5 tables, 29 ref

008915   Sinha B L;Rastogi R A;Saxena V K;Kumar D (Dep of Soil and Wat Conservation Engng Coll of Technol, G. B. Pant Univ of Agric and Technol, Pant Nagar-263 195) : A discrete linear rainfall-runoff model for Chaukhutia watershed. Indian J Soil Conserv 2005, 33(1), 13-17.

Discrete linear rainfall-runoff model for Chaukhutia watershed of Ramganga river was developed for estimating direct run off hydrographs on storm basis. The parameters of the model were determined by using least square method. The model was calibrated for twenty four storm events and verified for four storm events. The computed direct run off hydrographs by model were in close agreement with the observed direct runoff hydrographs. The average value of the integral square error and coefficient of efficiency were found to be 0.0568 and 0.9778, respectively. The regression equations were also established relating computed and observed peak runoff rates with effective rainfall.

4 illus, 1 table, 6 ref

008914   Singh R;Khicher M L (Dep of Agric Meteorology, CCS Haryana Agric Univ, Hisar-125 004) : Quantitative verification of medium range weather forecast. Ann agric biol Res 2005, 10(1), 11-14.

The analysis of quantitative verification of received weather forecasts from National Center for Medium Range Weather Forecast (NCMRWF), New Delhi has been carried out for the period from March 1999 to February 2001 on seasonal basis using the criteria of usable/unusable/and correct/false weather forecasts. It was found that usable and correct weather forecasts were very close in case of rainfall. The rainfall forecast was correct 93.2, 70.2, 98.5 and 82.8% during pre-monsoon, south-west monsoon, post-monsoon and winter seasons, respectively. The forecast of cloudiness was correct from 38.6% in south-west monsoon to 81.5% in pre-monsoon season. The total accuracy of forecasts in respect of maximum temperature, minimum temperature, wind speed and wind direction was observed 54.3, 43.3, 82.9 and 19.6%, respectively. The maximum deviation range between observed and forecasted values was noted for rainfall parameter during south-west monsoon season.

2 tables, 5 ref

008913   Shekhar S;Singh S B;Romani S (NO, Cent Ground Wat Bd, 18/11 Jamnagar House, Mansingh Road, New Delhi-11, Email: shashankshekhar_01@indiatimes.com) : Controls to the variation in depth to fresh/saline interface in the groundwater of southwest district, NCT, Delhi. J Geol Soc India 2005, 66(1), 17-20.

Hydrogeology of the southwest district of National Capital Territory (NCT) Delhi is challenging on the account of the fact that the quality of groundwater in the district shows horizontal and vertical variation with respect to salinity. The paper tries to study the variation in the depth to fresh (electrical conductivity equal to or below 1500-2000 micro Siemens per cm)/saline (electrical conductivity above 1500-2000 micro Siemens per cm) water interface of the district and locate the factors controlling the variation in the depth to fresh/saline interface in the groundwater of the district. The map showing variation in the depth to fresh/saline interface in the groundwater of the district was studied vis-a-vis geology and cultural practices in the district, in order to identify the factors controlling the variation in the depth to fresh/saline water interface in the groundwater of the district.

2 illus, 2 ref

008912   Sharma K K;Bhattacharya A K (NO, Cent Inst of Freshwater Aquaculture, Bhubaneswar-751 002) : Development of models for designing water harvesting ponds in the rainfed areas. Indian J Soil Conserv 2005, 33(1), 27-30.

Procedure for the design of water harvesting pond was developed. It comprises of rainfall analysis, runoff estimation by CN method, design of pond capacity, calculation of expected available water in ponds at various point of time and economic analysis of pond construction and irrigation activities using stored water. The study was carried out at three study sites viz Dasuya, Indore and Kanas for the assumed watershed areas of 5 ha to 100 ha at different probability levels of estimated runoff. Multiple regression models were developed for the design of water harvesting pond capacities.

2 tables, 8 ref

008911   Sethy B K;Ali S;Prasad S N (Cent Soil and Wat Conservation Res and Training Inst, Res Cent, Kota -324 002) : Frequency analysis for one day to five consecutive days annual maximum rainfall for South-Eastern Rajasthan. Indian J Soil Conserv 2005, 33(1), 22-6.

Design engineers and hydrologists require annual one day and two to five consecutive days maximum rainfall data corresponding to return period varying from 2 to 100 years and crop tolerance period that help in economic planning, design of small and medium hydraulic structures and determination of drainage coefficient for agricultural fields. Various probability distribution and transformations can be applied to estimate the one-day as well as consecutive days- annual maximum rainfall of various return periods. Five commonly used probability distribution functions (viz. Normal, Log-normal, Extreme value Type-I, Pearson Type-III and Log Pearson Type-III) were tested by comparing the Chi-squared values. 2 parameters log normal distribution was found to be the best fit frequency distribution function for the region. Simple regression models were developed for one day as well as 2 to 5-consecutive days annual maximum rainfall for the region. Thein's U-static indicated that consecutive days annual maximum rainfall model estimate was not statistically different from a 2-parameters lognormal estimate.

6 tables, 12 ref

008910   Sasi M N;Ramkumar G;Krishna Murthy B V (Space Phys Laboratory, Vikram Sarabhai Space Cent, Thiruvananthapuram-695 022, Email: bvkmurthy2@rediffmail.com) : Equatorial waves over the Indian zone. Curr Sci 2005, 89(3), 475-87.

As part of the Indian Middle Atmosphere Programme, three scientific campaigns were conducted to study equatorial waves in 1984, 1986 and 1988 from Trivandrum, SHAR and Balasore involving RH 200 rockets and balloonsondes for measurement of horizontal wind components. With the installation of MST radar and Rayleigh lidar at Gadanki, temperature could be determined in the middle atmosphere, enabling estimation of vertical flux of zonal momentum of the equatorial waves, which is a crucial parameter to understand the role of the equatorial waves in the generation of quasi biennial oscillation and semi annual oscillation. Making use of these facilities, three more campaigns were conducted to delineate the equatorial wave characteristics, including the wave momentum flux. The results of each of these campaigns have already been published. Here the results from all the six campaigns are reviewed, consolidated and examined in the light of the current global scenario of equatorial wave studies.

^iia11 illus, 2 tables, 32 ref

008909   Sanjeev Kumar;Ramesh R;Sheshshayee M S; Sardesai S;Patel P P (NO, Phys Res Laboratory, Ahmedabad-380 009) : Signature of terrestrial influence on nitrogen isotopic composition of suspended particulate matter in the Bay of Bengal. Curr Sci 2005, 88(5), 770-4.

Nitrogen concentration and its isotopic composition in surface suspended matter have been measured at 24 different locations during the post-monsoon season in the Bay of Bengal. In general, the stable nitrogen isotopic composition of surface particulate organic nitrogen (PON) in the Bay of Bengal appears to be a mixture of particulate matter from the continent and marine phyto-plankton, the latter having inherited the isotopic composition of deeper nitrate. Higher δ¹⁵N values of surface PON in open ocean locations could be due to the supply of nitrate with higher δ¹⁵N values. However, offshore locations have been diluted by the continental influence leading to low δ¹⁵N values in PON.

5 illus, 2 tables, 26 ref

008908   Sanilkumar K V;Hareesh Kumar P V (NO, Naval Phys and Oceanographic Laboratory, Thrikkakara, Kochi-682 021) : Eddies and planetary waves in the Central Arabian sea. J Indian Soc Remote Sens 2005, 33(1), 137-46.

Eddies and planetary waves are identified as one of the important factors that control the dynamics of the Arabian Sea. During 10-14 January 1990, Ignat, Paulyuchenkov (USSR ship) conducted an experiment in the central Arabian Sea and of late TOPEX/POSEIDON satellites collected data on sea surface height (SSH) anomalies of the Arabian Sea. These data sets give an opportunity to understand the characteristic of eddies and planetary waves in this region during winter. The geostrophic flow revealed three anticyclonic and two cyclonic eddies of diameters ranging from 75 to more than 150 km from surface to subsurface levels. Current speeds around different eddies were maximum at surface and varied from 9 cm/s to 25 cm/s (at the middle point between the center and periphery). The occurrence of eddies were further investigated with the TOPEX/POSEIDON altimetry for the years 1993-97. The analysis revealed multiple eddies of diameter 100 to 550 km occur every year with maximum number of eddies during 1997 and minimum during 1995. The calculated speed varied between 8-30 cm/s around various eddies. Longitude-Time plots showed annual Rossby waves generating at the eastern Arabian Sea and propagating westwards with a phase speed of <126> 10 cm/s along 16° N. Further, it was observed that these waves arrived in the study area by January. In addition, another positive anomaly of SSH was found generating at the western Arabian Sea simultaneously and extended up to the study region by April-June. Time series of SSH at selected locations along 16??øN revealed many small-scale oscillations and their spatial variability. These oscillations were delineated using the FFT analysis. Other than the Rossby wave, the major components at the study region were 40-60 and 26-32 day oscillations. The implications of these long period waves associated with eddies are discussed.

8 illus, 23 ref

008907   Saha R;Mishra V K (Div of Wat Mgmt, ICAR Res Complex for N.E.H. Region Umroi Rd, Umiam, Meghalayaj) : Probability analysis of rainfall at Meghalaya for crop planning. Indian J Soil Conserv 2005, 33(1), 86-7.

2 tables, 3 ref

008906   Rawat G;Nautiyal P (Dep of Zool, Univ of Allahabad, Allahabad-211002) : Estimates of benthic macroinveriebrate and ephemeropteran community diversity in mountain stream and rivers of lesser Himalaya. Univ Allahabad Stud-Sect A 2004, 3(1), 13-19.

The study was carried out on two lotic bodies of the Garhwal region in the lesser Himalaya. One of them, the Alaknanda is major tributary of the Ganga originating in the Greater Himalaya. The Alaknanda was sample upstream of Srinagar at an altitude of 560 meters a.s.1, latitude 30°13' 24"and longitude 78° 48' 24". The stream Khanda was sampled at Khanda Chatti located at an altitude of 714 m., latitude 30ø 11'36" N and longitude 78ø 46' 43" E. Samples was taken from right bank only in the Alaknanda and from both bank as well as middle of stream Khanda Gad. Use of square foot Surber's sampler was made in order to obtain the 10 representative sample of benthic macro in vertebrate. Samples were preserved in 5% formalin for analysis and identification of the sample with the help of various keys. In the study the species diversity was also used as a measure of similarity and differences in the community. The species diversity or richness did not differ significantly, in the Alaknanda and Khanda gad. The latter supported a relatively more diverse Ephemeropteran community. Compared to Khanda, Evenness was greater in the Alaknanda. This explains the stable nature of the benthic macro in vertebrate community in the Alaknanda, being more variable in the Khanda. Peak diversity of the benthic macroinvertebrate was observed during winter (January) and early summer (March) in the Alaknanda and Khanda gad, respectively. The peak diversity of Ephemeroptera was observed during summer (May) in the Alaknanda and post monsoon (September) in the Khanda gad.

1 table, 47 ref

008905   Ramkumar M;Subramanian V;Stuben D (Dep of Geol, Periyar Univ, Salem-636 011, Email: muramkumar@yahoo.co.in) : Deltaic sedimentation during cretaceous period in the northern Cauvery basin, South India: facies architecture, depositional history and sequence stratigraphy. J Geol Soc India 2005, 66(1), 81-94.

Santonian-Campanian sequence of the Cauvery basin was documented with lesser detail owing to its lesser fossiliferous nature and relatively highly fossiliferous bounding strata. Micro-mesoscale lithofacies analysis coupled with documentation of sedimentary and tectonic structures, supplemented by bio and ichnofacies data of the sequence revealed that this sedimentary record represents the development of Gilbert type delta. Various stages of delta development were interpreted to have resulted during a third order glacio-eustatic sea level cycle. It is surmised that faulting at the dawn of Santonian that brought down topographic and structural highlands into lows permitted marine transgression and creation of steeply sloping river valley, augmenting intense continental erosion and influx of detrital sediment into the basin. In due course of time, smoothening of valley slope, submergence of river mouth by rising sea level coupled with cessation of detrital influx led to the demise of the deltaic deposition. The information that the bounding surfaces of this Santonian-Campanian sequences are recognised to be of sea level lowstands, that led to generation of good reservoir quality in the ensuing depositional products, when coupled with the occurrences of gas and oil pools in the sequence in offshore area of this basin necessitates intense exploration activities. The study has also indicated the presence of three types of variability of reservoir characteristics as defined by three systems tracts.

9 illus, 1 table, 51 rf

008904   Ramesh Chand;Hodlur G K;Ravi Prakash M;Mondal N C;Singh V S (NO, Natn Geophys Res Inst, Uppal Road, Hyderabad-500 007) : Reliable natural recharge estimates in granitic terrain. Curr Sci 2005, 88(5), 821-4.

The average natural recharge to the aquifer of Kongal river basin located in Nalgonda district, Andhra Pradesh, India due to the monsoons is estimated using injected tritium technique at a few selected sites. Kriging and Thiessen Polygon methods are employed to interpolate recharge estimates and arrive at more realistic values. The estimate is made from the spatial distribution of recharge values. The spatial distribution of recharge values is derived from 25 site-specific measurements. The quantum of groundwater recharge through vertical infiltration has been estimated as 27.5 and 30.0 mm (l^-2) by Kriging and Thiessen polygon methods respectively; a value of 25.0 mm (1^-2) was arrived at using average recharge values in the area. The total rainfall during the corresponding period is 566.67 mm (l^-2) and thus the fractional amount of recharge is 5% of the rainfall.

3 illus, 12 tables, 22 ref

008903   Ramakrishnan D;Ghosh S K;Raja V K M;Chandran R V;Jeyram A (Regional Remote Sens Serv Cent Indian Space Res Organization, Indian Inst of Technol Campus, Kharagpur-721 302, Email: aarkay_geol@yahoo.com) : Trails of the killer tsunami: A preliminary assessment using satellite remote sensing technique. Curr Sci 2005, 88(5), 709-11.

3 illus, 14 ref

008902   Pratap Singh;Haritashya U K;Ramasastri K S; Naresh Kumar (NO, Natn Inst of Hydrology, Roorkee-247 667, Email: pratap@nih.ernet.in) : Prevailing weather conditions during summer seasons around Gangotri glacier. Curr Sci 2005, 88(5), 753-60.

Meteorological data collected near the snout of the Gangotri Glacier suggest that the study area receives less rainfall. The average seasonal rainfall is observed to be about 260 mm. The rainfall distribution does not show any monsoon impact. Amount of seasonal rainfall is highly variable (131.4-368.8 mm) from year to year, but, in general, August had the maximum rainfall. Average daily maximum and minimum temperatures were 14.7 and 4.1°C respectively, whereas average mean temperature was 9.4°C. July was recorded as the warmest month. During daytime, wind speed was four times higher than that at night-time. The average daytime and night-time winds were 12.6 and 3.0 km/h respectively. Mean seasonal evaporation was 640.8 mm, which is high with respect to the high altitude. Average relative humidity and daily sunshine duration were also high throughout the melting season.

7 illus, 19 ref

008901   Parekh A;Sarkar A;Ravichandran M (Oceanic Sci Div Meteorology and Oceanography Grp, Space Applics Cent (ISRO), Ahmedabad-380 015, Email: sarkar_abhi2000@yahoo.com) : Surface winds in the arabian sea from MSMR an empirical approach. J Indian Soc Remote Sens 2005, 33(1), (NULL).

Multi-channel Scanning Microwave Radiometer (MSMR) onboard IRS P4 (Oceansat I) measured Brightness Temperature data of the different bands are found sensitive to the surface and the overlying atmosphere to different degrees. A judicious combination of multi-channel data can provide such oceanic/atmospheric parameters as surface wind speed, sea surface temperature, water vapour in the marine atmosphere, etc. Highlights results obtained in relation to surface wind speed. Co-location and concurrence of several ocean data buoys in the Arabian Sea with MSMR observations allowed empirical construction of D-matrix coefficients for surface wind speed. With both MSMR and the Arabian Sea buoys functioning for the period of one and a half year (June, 1999 to December, 2000) without interruptions provided a large database. All channels are found to exhibit moderate sensitivity to surface wind speed. MSMR data in the immediate vicinity (within 150 km) of the buoy locations and within a time window of one hour were used. A multi-channel linear equation for surface wind speed was subsequently derived. The equation was subjected to tests with independent data set for the period January - June 2001 over the Arabian Sea and found to be moderately accurate. The empirical equation is expected to be useful for regional applications over the Arabian Sea and over regions closer to west coasts, which might have been flagged out in the operational geophysical data stream. An interesting subset of data revealed the wind signatures of the May 2001 cyclone in the Arabian Sea.

3 illus, 13 ref

008900   Pant G B;Joshi R R;Damle S H;Deshpandey S M; Singh N;Vashistha R D;Neekhra P;Chande J V;Kulkarni A A;Pillai J S (NO, Indian Inst of Trop Meteorology, Pune-411 005) : Wind profiler and radio acoustic sounding system at IMD, Pune: Some preliminary results. Curr Sci 2005, 88(5), 761-9.

A 404 MHz Wind Profiler/Radio Acoustic Sounding System fabricated by the Society for Applied Microwave Electronics Engineering and Research, Mumbai has been commissioned for utilization in the R&D mode at the India Meteorological Department, Pune. The system is capable of measuring all three components of vector wind, viz. zonal, meridional and vertical wind velocities. The system as configured has a typical height coverage of 6-10 km (depending on weather conditions) with a resolution of 300 m for wind and 2-3 km for temperature measurement. Regular observations with the system have commenced since June 2003. Article gives a brief introduction to the system and present preliminary results for wind and temperature obtained during monsoon season 2003 and discuss the further application potential of the indigenously developed system.

6 illus, 2 tables, 11 ref

008899   Nook Ratnam K;Srivastava Y K;Venkateswara Rao V;Amminedu E;Murthy K S R (Dep of Geo-Engineering, Coll of Engng Andhra Univ, Visakhapatnam-530 003) : Check dam positioning by prioritization of micro-watersheds using Syi model and morphometric analysis-remote sensing and Gis perspective. J Indian Soc Remote Sens 2005, 33(1), 25-38.

Sediment Yield Index (SYI) model and results of morphometric analysis have been used to prioritize watersheds and to locate sites for checkdam positioning in Tarafeni watershed in Midnapur district, West Bengal. Various thematic maps such as land use/land cover, slope, drainage, soil etc. were prepared from IRS 1D LISS III digital data. SOI toposheets of 1:50,000 scale and other reference maps. Morphometric parameters such as bifurcation ratio (R_b), drainage density (D_d), texture ratio (T), length of overland flow (L_o), stream frequency (F_u), compactness coefficient (C_c), circularity ratio (R_c), elongation ratio (E_f), shape factor (B_s) and form factor (R_f) were computed. Automated demarcation of prioritization of micro-watersheds was done by using GIS overlaying technique by assigning weight factors to all the identified features in each thematic map and ranks were assigned to the morphometric parameters. Five categories of priority viz., very high, high, medium, low and very low, were given to all the watersheds in both the methods. Sixty-two micro-watersheds using SYI method and twenty-three micro-watersheds using morphometric have been prioritized as very high priority. Final priority map was prepared by considering the commonly occurred very high-prioritized micro-watersheds in both SYI model and morphometric analysis. Twenty-four suitable sites were identified for check dam construction in 21 highly prioritized watersheds. It is proved that integrated study of SYI model and morphometric analysis yield good result in prioritization of watersheds.

7 illus, 5 tables, 8 ref

008898   Navalgund R R (NO, Natn Remote Sens Agency, Hyderabad-500 037) : Sumatra tsunami of December 26, 2004. J Indian Soc Remote Sens 2005, 33(1), 1-6.

4 illus

008897   Nallapa Reddy A;Satyanarayana K;Bhaktavatsala K V;Narasimha K;Nagaraj M (Regional Laboratory, ONGC Ltd., N.H. Road, Chennai-600 034, Email: anreddy_54@yahoo.com) : Sequence stratigraphy and depositional process of miocene-sediments in KD-structure, deepwaters of Krishna-Godavari basin, India. J Geol Soc India 2005, 66(1), 42-58.

Detailed chronostratigraphic biodatums and lithofacies in combination with correlative seismic horizons recognized two 3rd order depositional sequences designated as Sequence 1 and Sequence 2 in stratigraphic order within Miocene in KD field. The biostratigraphic correlation has brought out that the Sequence 1 in shelf well GS-AD is sand-rich and bounded by unconformable sequence boundaries, whereas coeval sequence in slope wells KDA and KDB, bounded by correlative conformities are dominated by clay rich system deposited during highstand sea-levels in early-middle Miocene. The clays are planar bedded with glauconite and pyrite nuggets with abundant deepwater benthics in association with shelf derived foraminifera, inferring that these clays were derived into intraslope basins mainly as debris flow/slump process. The Sequence 2 in wells KDA and KDB is represented by multiple sands with mudstone alternations, deposited during lowstand sea-levels. Biofacies are mixed with dominantly shelf derived benthics and the tests are commonly broken, abraded and occasionally ferruginised, suggesting reworking into intraslope basins as a result of relative sea-level fall during middle and late Miocene. The occurrence of abundant Paleocene to early Miocene dinoflagellate cyst assemblage are also suggesting reworking process into upper slope by network of active channel system and were redeposited by gravity-flow processes into intraslope basins. The study indicates each intraslope basin acting as an independent petroleum system and matured organic rich Paleogene beds lying at the bottom are contributing hydrocarbons to middle Miocene reservoirs through active growth fault system.

9 illus, 2 tables, 33 ref

008896   Nageswara Rao P;Som A;Perumal T;Maithani P B; Saxena V P;Sinha R M (Dep of Atom Energy, Atom Miner Directorate for Explor and Res, Begumpet, Hyderabad-500 016) : Proterozoic unconformity-related uranium occurrence around Rallavagu Tanda, Palnadu sub-Basin, Andhra Pradesh. J Geol Soc India 2005, 66(1), 11-14.

Recent investigations have brought out significant uranium occurrences (up to 0.65% U₃O₈) spread over as discontinuous zones (up to 300 m x 280 m x 1 -3 m) over an area of about 7 km x 2 km along the northern part of Palnadu sub-basin. The radioactive zones are exposed along the Upper Proterozoic unconformity contact between the basement granite and the Banganapalle quartzite near Lavur Tanda, Jaitram Tanda, Boligutta Tanda, Rallavagu Tanda and Gandhi Nagar villages in Nalgonda district, Andhra Pradesh. These findings are reported in this note along with some features of mineralisation.

3 illus, 1 table, 10 ref

008895   Minakshi;Sharma P K;Amandeep Kaur;Shalley V (NO, Punjab Remote Sens Cent, Ludhiana-141 004) : Satellite based study of land transformation in Ludhiana district, Punjab. J Indian Soc Remote Sens 2005, 33(1), 63-8.

Study reveals the temporal changes in the land use/land cover of district Ludhiana from the years 1970 to 2001 and reports on the change that has occurred in land use/land cover as a result of change in cropping pattern. The changes were analysed through the data obtained from statistical abstract 1969-70, False Colour Composite (FCC) of IRS-1C LISS-III satellite data of March 2001 and ground truth. There has been a decrease in agricultural land by 2100 ha. but still it occupies 83.76% of the total geographical area (TGA). The wasteland shows a declining trend whereas forest cover has increased from 1.07 to 2.71% of TGA. Area under non-agricultural uses has increased from 10.13 to 12.50% of TGA. There has also been a great change in the cropping pattern of the district. Crops such as groundnut, gram and cotton have nearly disappeared and wheat and rice dominate the region. This change has substantially resulted in the decrease of area under wastelands.

3 illus, 2 tables, 6 ref

008894   Kar G;Verma H N (NO, Wat Technol Cent for East Region (ICAR), Bhubaneswar-751 023) : GIS based crop water management analysis for Eastern Ghats and coastal region. Indian J Soil Conserv 2005, 33(1), 1-7.

GIS based crop water management analysis was made for developing alternative land and water resources planning for Eastern Ghats and coastal region. As per climatic water balance study, large to moderate water surplus (500-650 mm) was available in agro-ecological subregion (AESR) 12.1. The rainfall surplus of 200 to 350 mm was computed in AESR 12.2 and 350 to 500 mm in AESR 12.3. Since winter rainfall is meager and erratic this may be harvested and utilized for providing supplementary irrigation to winter crops or during dry spell of rainy season crops. Study revealed that at 80% probability level in first month of southwest monsoon (June), average 121 mm rainfall occurred in AESR 12.1, 122 mm in AESR 12.2 and 114 to 132 mm in AESR 12.3. These amounts of rainfall are sufficient to prepare land and sowing of upland direct seeded crops like maize, groundnut, blackgram, greengram, pigeonpea, cowpea etc. that may be done from 24th standard weeks onwards (11th to 17th June) after onset of southwest monsoon. In normal rainfall year, 450 to 552 mm, 600 to 720 mm and 775 to 875 mm crop water requirement was computed using Cropwat 4.0 model for autumn rice and summer rice, respectively in different AESRs.

9 illus, 6 tables, 15 ref

008893   John B;Rajendran C P (NO, Geol Surv of India, Northern Region, Lucknow-226 020, Email: cp_r@vsnl.com) : Constraining the pattern of deformation associated with low-displacement faults in the cratonic regions: an example from the precambrian province of Kerala, South India. J Geol Soc India 2005, 66(1), 29-41.

Surface exposure of a suspected active fault in an intraplate region, in the state of Kerala, South India revealed subtle expressions of brittle deformation in exhumed crystalline bedrock. The deformation zone consists of fracture sets with small-scale displacement and slip planes containing gouge; the propagation of displacement at depth being accommodated through fracture planes in the upper levels of the crust. It is spatially coincident with a linear hill scarp, and also the isoseismal elongation of a recent slight earthquake (M=4.3) in this zone. The fault rocks present within the fracture zone indicate cyclic episodes of frictional slips along the fault, which may have led to a progressive increase in the gouge thickness. Major part of the gouge zone along the fault shows alteration at the expense of feldspar and mica. The occurrence of repeated rupture may also imply that the fault zone re-strengthened between each rupture. The structural analysis suggests different generations of fault gouge and the last major episode of frictional sliding may have occurred close to the surface. Available data on the electron spin resonance (ESR) dating of the gouge indicates an age of 430 ± 43 ka, probably representing the last major displacement on this fault. The structural interpretation of the fault rocks suggests that the suitably oriented discrete fault strands, within the Precambrian shear zone can be the source of moderate earthquakes (M <1472>6.0) but slip events are separated by long periods of quiescence. Possible ways of constraining the nature of activity and the pattern of deformation associated with low-displacement faults that occur within the Precambrian cratons have been suggested.

8 illus, 1 table, 25 ref

008892   Gultekin A H (NO, Istanbul Teknik Universitesi, Maden Fakultesi, 80626 Maslak, Istanbul, Turkey, Email: gultekin@itu.edu.tr) : Epithermal kizilcaoren fluorite-barite REE deposit, Eskisehir, Turkey. J Geol Soc India 2005, 66(1), 105-16.

Kizilcaoren is a vein-type, fault controlled fluorite-barite-rare earth element (REE) deposit and forms the only economic REE and thorium source of Turkey. The ore-bearing veins formed by hydrothermal solutions originating from alkaline volcanism occur in a wide variety of host rocks ranging from metasandstones to pyroclastics. The host rocks show three types of hypogene alteration of varying intensity: silicification, argillic alteration, and sericitization. Three main economic ore types identified were fluorite ore, massive barite ore, and bastnaesite+fluorite+barite ore. Fluid inclusion measurements from barite and bastnaesite show low salinity of 0.5-9.5 eq. wt.% NaCl and homogenization temperatures of 105°C and 246°C respectively. Fluorite was formed from slightly higher salinity (<60>12.4 wt.% NaCl equiv.) fluids at low- and moderate-temperatures (163-336°C). Relatively low-salinity and low-and moderate temperature inclusions might be the result of mixing of deep-saline brines with low-salinity meteoric fluids. Sulphur isotopic composition suggests a source similar to that of the hydrothermal fluids which are compatible with volcanogenic sulphate field.

7 illus, 3 tables, 31 ref

008891   Goswami S B (AICRP on Wat Mgmt, Bidhan Chandra Krishi Viswavidyalaya, PO-Gayeshpur, Nadia-741 234) : Surface drainage practice for vegetables during high rainfall in lower Gangetic plains. Indian J Soil Conserv 2005, 33(1), 31-4.

Vegetables like pointed gourd, brinjal, cauliflower and cabbage gave good yields in rainy seasons when they were grown on raised bed in sandy loam soils. The provision of open parallel drains consisting of main, lateral and sub lateral in sandy loam soil condition proved worthiness to alternate the water congestion in vegetables grown in rainy season of lower Gangetic alluvial plains of West Bengal. The adopted drainage design in study was trapezoidal in cross section (top 40-60 cm; bottom 30-50 cm with side slope 1.2-1.6 and depth 10-25 cm) and drainage channel length varied to the order of 8-16 m and sub lateral, lateral and main drain were spaced at 0.6-1.0 m, 6-8 m, 8-16 m apart respectively in accordance with the crop requirement and slope of the land. As a result of provision of open drainage in the vegetable field the drainage rate improved up to 10.8-25 1s^-1 and 2-6 cm ponded water drained out in 30-40 minutes and excess surface and subsurface water drains within 4-5 hrs when peak intensity of rain fall varied from 30-45 mm h^-1.

4 illus, 6 tables, 8 ref

008890   Dasgupta H C;Mishra S (Dep of Geol and Geophysics, Indian Inst of Technol, Kharagpur-721302, Email: hcd@rediffmail.com) : Petrogenesis of Hudupahar-Gitilgarh metabasic rocks in Chhotanagpur granite gneiss, Eastern India. J Geol Soc India 2005, 66(1), 66-80.

Hypersthene- to minor olivine-normative low K-quartz tholeiites occurring in Hudupahar-Gitilgarh area of Chhotanagpur Granite Gneissic Complex appear to have formed at low pressure (<60>10Kb) conditions. Small range and mutually coherent, regular patterns of distribution of the major and trace elements in Harker-type and other variation diagrams and tight clustering of all data points in Pearce Element Ratio plots indicate unaltered and uncontaminated and comagmatic nature of the melt for the (meta)-basic rocks subjected to clinopyroxene, plagioclase and minor olivine fractionation. Multielement spidergrams and trace element modelling for a number of compatible-incompatible pairs suggest that these rocks are products of partial melting of depleted mantle which possibly has been metasomatically slightly enriched in some but depleted in other elements prior to melting. Approximately <126>15% partial melting of the mantle followed by fractional crystallization of upto 20-30% in the melt appears to have been the probable mechanism for the generation of these tholeiites.

11 illus, 5 tables, 47 ref

008889   Chauhan P;Nayak S (Mar and Wat Resources Grp, Space Applics Cent (Indian Space Res Organization), Ahmedabad-380 012) : Detection of submerged reef banks in the Lakshadweep Sea using IRS-P4 OCM satellite data. Curr Sci 2005, 89(3), 557-60.

The coral reef systems of the Lakshadweep region are unique from an ecological perspective. The region around Lakshadweep Islands is characterized by shallow submerged reef banks. The study demonstrates the use of IRS-P4 OCM satellite data in deciphering information about the extent of submerged reef banks in this area. The short wavelength OCM spectral bands have been found to be useful in detecting submerged reef banks as deep as 50-60 m below the ocean surface. This information is useful for updating navigational charts and to minimize ecological losses for the reefs of this region.

5 illus, 9 ref

008888   Chattopadhyay B K;Goswami J N;Murty S V S; Thapliyal A P;Ghosh J B;Shukla P N;Shukla A D;Mondal P K;Pant N C; Sinha N (Cent Petrological Laboratories, Geol Surv of India, Kolkata-700 016) : Meteorite falls over India during 2003: Petrographic and chemical caracterization and cosmogenic records. Curr Sci 2005, 88(5), 774-8.

Two meteorite falls observed over India in 2003 led to the recovery of surviving fragments. The Kasauli meteorite that fell in northern India is a single fall, while Kendrapara meteorite is a multiple fall that covered a large coastal region of Orissa. Data for petrographic characteristics and chemical composition suggest that the two meteorites belong to the H group of chondrites, with Kasuali suffering a lesser degree of thermal meta morphism than Kendrapara during their residence in their parent bodies. Cosmogenic records indicate a large size (≥ 1 m) for the Kendrapara meteoroid that has spent <126>5 million years in interplanetary space following its ejection from its parent body until its fall on the Earth. On the other hand, the Kasauli meteoroid spent ah unusually long time (<126>37 Ma) in interplanetary space before its fall and lost <126>80% of its original mass during atmospheric ablation.

2 illus, 1 table, 9 ref

008887   Bayhan E (Dep of Geol Engng, Hacettepe Univ, 06532 Beytepe, Ankara, Turkey, Email: ebayhan@hacettepe.edu.tr) : Tertiary clay mineralogy of the Cokelezdag region (NE Denizli-SW Turkey): origin and provenance. J Geol Soc India 2005, 66(1), 21-7.

Study is carried out in the vicinity of Cokelezdag (NE of Denizli, Turkey), the tertiary sedimentary sequences unconformably overly the Mesozoic basement rocks. A number of samples were collected from the measured stratigraphical section, and whole rock and clay mineralogy were determined from these samples. Calcite, mica, feldspar, quartz, clay and dolomite are the main minerals identified. In the clay fraction, smectite is the dominant clay mineral; lesser amounts of illite, chlorite, kaolinite and serpentine were also identified. Provenance studies indicated that the sediments were transported from two different source areas, namely are Taurid ophiolitic belt and Menderes metamorphic massif. Magnesium rich fractions and aluminium rich fractions were derived from the Taurid ophiolitic belt and the Menderes metamorphic massif respectively.

5 illus, 2 tables, 27 ref

008886   Basu A;Das L K;Moitra M;Bhattacharya D;Lahiri A K (Mar Wing (HQ), GSI, Kolkata, Bhubijnan Bhawan, Karunamoyee, Salt Lake, Kolkata-700 091) : On the occurrence of rocks of lamproitic affinity in Singhbhum granite, near Rajnagar-Tiring area district East Singhbhum, Jharkhand. J Geol Soc India 2005, 66(1), 15-16.

Note records the occurrence of a lamproitic body traversing the Archaean greenstone belt in Singhbhum craton near Rajnagar-Tiring area in east Singhbhum district of Jharkhand. This discovery opens up new vistas of search for similar rocks in this region.

1 illus, 6 ref

008885   Bahuguna I M;Kukarni A V (Space Applics Cent, Indian Space Res Organisation, Ahmedabad-380 015, Email: imbahuguna@sac.isro.org) : Application of digital elevation model and orthoimages derived from IRS-1C pan stereo data in monitoring variations in glacial dimensions. J Indian Soc Remote Sens 2005, 33(1), 107-12.

Attempt has been made to study variations in the glacier extent over a period of time using digital elevation model (DEM) and orthoimages derived from IRS-1C PAN stereo pairs of 1997-98 and topographical map surveyed during 1962-63. DEM and orthoimages have been generated using integrated software developed for processing of IRS 1C/ 1D panchromatic stereo data using the softcopy photogrammetric workstation. Case studies of two glaciers, i.e. the janapa garang and Shaune garang glaciers of the Basapa basin, a sub-basin of Satluj River in India, have been presented here. Generation of DEM has been followed by the estimation of its accuracy. PAN images were interpreted for identification of the snout of the glaciers. The geographical locations of the snouts on the images were compared with the location as mapped on the topographical map of the study area. To verify satellite observations, field investigations were carried out at Shaune garang glacier area. The Janapa garang and the Shaune garang are observed to have retreat of 596m and 923 m respectively. Reduction in the thickness of ice in the deglaciated part of the Shaune garang glacier was estimated on the basis of change in the elevations of the glacial surface from 1963 to 1998.

4 illus, 3 tables, 10 ref

008884   Armstrong-Altrin J S;Madhavaraju J;Ramasamy S;Gladwin Gnana Asir N (Centro de Investigaciones en Ciencias de la Tierra, Universidad Autonoma del Estado de Hidalgo, Ciudad Universitaria, Carretera Pachuca-Tulancingo km. 4.5, Pachuca, Hidalgo, 42184, Mexico, Email: altrina@uaeh.reduaeh.mx) : Provenance and depositional history of sandstones from the upper miocene Kudankulam formation, Tamil Nadu. J Geol Soc India 2005, 66(1), 59-65.

Quartz grains from Kudankulam Formation were studied using Scanning Electron Microscope (SEM), which brought out eighteen microtextures. The quartz grains of Kudankulam Formation show different types of conchoidal fracture, arcuate steps, V-shaped patterns, pits and sub-angular to sub-rounded outline. The presence of conchoidal fracture and arcuate steps suggest that these quartz grains were derived from the nearby crystalline source. The microtextures such as V-shaped patterns, pits, straight and curved scratches are characteristic of marine environment.

13 illus, 1 table, 37 ref

008883   Ambast S K;Keshari A K;Gosain A K (Div of Irrigation and Drainage Engng, Cent Soil Salinity Res Inst, Karnal-132 001, Email: skambast@essri.ren.nic.in) : A simple procedure for estimating distributed daily evapotranspiration using landsat-TM data. J Indian Soc Remote Sens 2005, 33(1), 39-49.

Procedure to estimate distributed daily evapotranspiration (ET) using remotely sensed data is presented. Landsat-TM data for a part of the Western Yamuna Canal command (Haryana) has been used for model application. The model utilizes the surface reflectance in visible, infrared and thermal bands to generate surface albedo, surface temperature and leaf area index and thus surface energy fluxes to determine distributed daily ET. Result reveals a reasonable estimate of distributed daily ET. For well-watered crop, average ET by the proposed model is estimated as 1.8 mm/d. whereas using Penmen-Monteith equation it is calculated as 1.9 mm/d. The error involved in estimating ET by the proposed model is calculated about 5%, which is quite acceptable for most applications. The proposed procedure is also found computationally simple and can also be applied on current Landsat ETM+ data.

5 illus, 1 table, 30 ref

008882   Algarsamy R;Zhang J (Chem Oceanography Div, Natn Inst of Oceanography, Dona Paula, Goa-403 004) : Comparative studies on trace metal geochemistry in Indian and Chinese rivers. Curr Sci 2005, 89(2), 299-309.

The trace metal geochemistry in Indian and Chinese rivers in the Asian region was studied to understand its variation on a global scale in terms of climate, geological conditions and anthropogenic impact The average particulate trace metal concentration of Indian rivers (<126> 300-1000 μg g^-1 is higher than that of Chinese rivers (<126> 150-300 μg g^-1) and the global average (<126> 170-350 μg g^-1). Molar ratios of alkaline and alkaline earth metals to Fe and Al (i.e. segregation factor, SF) were calculated in Indian bed sediment and in suspended matter of Chinese rivers to determine metal reactivity over the drainage basin. The segregation factors for bed sediments in Indian rivers were generally <60> 1, except for the Tapti (<126> 1.7) and the Godavari (1.4) systems. Regional and watershed differences in segregation factors were observed, reflecting variable weathering rates due to differing mineralogy, preferential removal of alkaline and alkaline-earth metals relative to oxide-forming elements (Fe and Al), and a regional climatic shift north to south from temperate to sub-tropical conditions. Elevated levels of lead in Chinese rivers and of cobalt and zinc in Indian rivers indicated anthropogenic inputs of these heavy metals.

5 illus, 5 tables, 52 ref

007806   Venkataiah C;Shivaprasad K H;Reddy S; Shivakumar K S (Dep Earth Sci, Gulbarga University Post-Graduate Center, Nandihalli-Sandur-583 119) : Extraction of lead from galena by slurry chlorination. Indian Mineralogist 2005, 39(1), 31-4.

Depletion of high-grade ores and the increasing demand for the metals has led to the use of other low-cost and environmentally friendly techniques of hydrometallurgy for recovering metal values from low-grade ores, where normal methods are not effective. In the investigation, an attempt has been made to extract lead from galena (PbS) ore by slurry chlorination. The ore samples analyzing 4.84% lead were obtained from Bandalamottu of Andhra Pradesh. Optimum conditions for the extraction of lead were determined by conducting a series of experiments. The effects of variables like percent solids, time, temperature, rate of chlorine gas flow and stirring on leaching were studied. It has been found that 92% of lead present in ROM samples can be extracted into the solution. The reaction mechanism for the dissolution of lead follows a shrinking model. The reaction has been found to be of first order with activation energy of 5.66 kcal/mole.

5 illus, 1 table, 6 ref

007805   Suresh R;Bhatnagar A K (Cyclone Detection Radar station India Meteorological Dep, , Chennai-600 001) : Pre-convective environment of pre-monsoon thunderstorms around Chennai- A thermodynamical study. Mausam 2005, 56(3), 659-70.

Pre-convective environment around Chennai during March-May 2003 has been studied using 0000 UTC upper air (RS/RW) and 0600 and 0900 UTC surface meteorological data. The study revealed the following results:(i) prevalence of positive (negative) dew point anomaly at 850 hPa, convective instability exceeding -6° K/km (convective stability, i.e., lapse rate less than -3° K/km) between 1000 and 700 hPa and positive (negative) relative humidity anomaly in the layer 850-500 hPa at 0000 UTC are associated with strong (no) convection (ii) SSE^ly to NNW^ly at 850 hPa is favourable for strong convection whereas ENE^ly to SSE^ly winds at 850 hPa are associated with no convection (iii) George's K index, Deep Convective Index and Showalter's stability index show better forecasting skill over the method of persistency (iv) Galway's lifted index, SWEAT index, humidity index and Boyden index do not have forecasting skill over persistency and hence they are considered unsuitable for forecasting thunderstorm during pre-monsoon season (March-May) over Chennai and (v) forecast based on 0000 UTC convective available potential energy (CAPE) and convective inhibition energy (CINE) does not throw any light in improving our forecasting skill.

6 illus, 8 tables, 36 ref

007804   Suresh R;Bhatnagar A K (India Meteorological Dep, , Chennai-600 001) : Seasonal variability of raindrop size distribution over Cuddalore, a coastal station in Tamil Nadu of southern peninsular India. Mausam 2005, 56(3), 643-58.

Cuddalore (11.46°N / 79.46°E), a tropical coastal station in Tamilnadu of southern peninsular India receives precipitation from pre-monsoon (March-May), southwest monsoon (June-September) and northeast monsoon (October-December). While the precipitation during pre-monsoon (PM) and southwest monsoon (SWM) is mostly convective, that received during northeast monsoon (NEM) is mostly stratiform albeit a juxtaposition of both convective and stratiform is also feasible. The seasonal variability of raindrop size distribution (DSD) has been studied using the data obtained from electro-mechanical disdrometer (Joss-Waldvogel type) at Cuddalore. The modal drop size is less than 2.0 mm diameter in stratiform precipitation whereas drops of higher diameter (more than 3 mm) is quite probable in convective precipitation events. The mean concentration of rain drops of size-more than 3 mm is highest during pre-monsoon followed by southwest monsoon in rain rates exceeding 10 mm h^-1 due to rapid collision and coalescence taking place in afternoon mixing and convective currents. The concentration of smaller size drops (of size less than 2 mm dia) especially in rain rates exceeding 8 mm h^-1 is more during NEM than the SWM because the condensed particles could not grow effectively into larger drops due to the prevalence of either weak instability or nocturnal stability conditions during NEM. Convective type precipitation has higher rain rates than the stratiform type. Inverse relationship between drop concentration and rain rate is seen during convective situations, while the relationship is linear during stratiform conditions. Lognormal distribution fits the DSD of northeast monsoon (mostly stratiform precipitation) extremely well. However, this fitting has some deviation in the rain rate 10-50 mm h^-1 during pre-monsoon and southwest monsoon season (mostly convective precipitation) based on the limited data sample obtained during 2003.

9 illus, 8 tables, 33 ref

007803   Singh T N;Kanchan R;Verma A K;Saigal K (Dep Earth Sci, Indian Institute of Technology, Powai, Mumbai 400 076, Email: tnsingh@iitb.ac.in ) : Comparative study of ANN and Neuro-fuzzy for the prediction of dynamic constant of rockmass. J Earth Syst Sci 2005, 114(1), 75-86.

Physico-mechanical properties of rocks have great significance in all operational parts in mining activities, from exploration to final dispatch of material. Compressional wave velocity (p-wave velocity) and anisotropic behaviour of rocks are two such properties which help to understand the rock response under varying stress conditions. They also influence the breakage mechanism of rock. There are different methods to determine the p-wave velocity and anisotropy in situ and in the laboratory. These methods are cumbersome and time consuming. Fuzzy set theory, Fuzzy logic and Neural Networks techniques seem very well suited for typical geotechnical problems. In conjunction with statistics and conventional mathematical methods, hybrid methods can be developed that may prove to be a step forward in modeling geotechnical problems. Here, authors have developed and compared two different models, Neuro-fuzzy systems (combination of fuzzy and artificial neural network systems) and Artificial neural network systems, for the prediction of compressional wave velocity.

7 illus, 2 tables, 21 ref