003195   Jain C K (National Inst of Hydrology, , Roorkee-247 667) : Ground water quality of district Dehradun, Uttranchal. Indian J Envir Ecoplann 2004, 8(2), 475-84.

The ground water quality of district Dehradun in the state of Uttaranchal (India) has been assessed to examined the suitablity of ground water for domestic application. Forty ground water samples (including 15 spring samples) were collected during pre and post-monsoon seasons during the year 2002 and analysed for various water quality constituents. the hydrochemical and becteriological data was analysed with reference to BIS and WHO standards and hydro-chemical facies were determined. One sample of Sahasradhara crosses the maximum permissible limit for hardness, calcium, magnesium and sulphate. The bacteriological analysis of the samples shows bacterial contamination at several places. In the case of spring samples, most of the samples are showing bacterial contamination with more than 60% of the samples exceeding the permissible limit of 10 coliforms per 100 ml. It is recommended that water drawn from such sources should be properly disinfected before being used for domestic use. The heavy metals in ground water except iron and nickel, which are present in appreciable concentration, were found below the permissible limits. The grouping of samples according to their hydro-chemical facles indicate that majority of the samples fall in Ca-Mg-HCO₃ followed by Ca-Mg-Cl-SO₄ hydro-chemical facies.

3 illus, 5 tables, 6 ref

003194   Goyal R K;Gupta V P (Central Arid Zone Res Inst, , Jodhpur-342 003) : Relationship among reference evapotranspiration models for arid region of Rajasthan. Ann Arid Zone 2003, 42(1), 13-9.

There are many methods for estimation of reference evapotranspiration (ET_o). These methods have been developed for specific sites, and need to be tested for other regions before their application. Several researchers have compared the results obtained from different evapotranspiration methods. However, no single existing method is universally applicable under all climatic conditions. Application of many of these methods is restricted because of large amount of data required. There has always been a need to estimate ET using limited meteorological data, whatsoever is available, Keeping in view the above difficulty, a study was undertaken to develop interrelationships among frequently used models for estimation of reference ET. Several standard models, namely Blaney-Criddle. Radiation, modified Penman and most recently developed Penman-Monteith and others have been used to develop interrelationships. about 30 years of weekly meteorological data of Jodhpur (Rajasthan) have been used to develop the interrelationships. Such interrelationships could be used as an additional tool to convert ET_o estimated by one method to another method. Interrelationships between different models of ET_o are also used for comparing the performance of different models. The present paper provides an opportunity to select a method of using limited available data under arid zone conditions.

2 tables, 17 ref

003193   Dinesh Kumar;Chaturvedi S;Singh R V (Chem Dep, Univ of Rajasthan, Jaipur-302 004) : A study on the characteristics of polluted water of amanishah nallah and neighbouring ground water sources with reference of heavy metal contents. Indian J Envir Ecoplann 2004, 8(2), 371-4.

The investigations were carried out to evaluate the magnitude of physico-chemical parameters of the water of the Amanishah Nallah and neighbouring ground water sources in Sanganer town of Jaipur city. The industrial effluent's contain large number of heavy metals which are the most harmful pollutants. The effluent in the area is discharged into Amanishah nallah. The metals monitored are iron, chromium, cadmium, nickel, zinc, copper and lead. Physico-chemical monitoring was carried out during the monsoon season in July, 2003. The quality parameters were compared with standards laid by WHO and ICMR for drinking water quality.

2 tables, 6 ref

003192   Chauhan O S;Patil S K;Suneethi J (Natnl Inst of Oceanography, , Dona Paula, Goa-403 004) : Fluvial influx and weathering history of the Himalayas since Last Glacial Maxima -isotopic, sedimentological and magnetic records from the bay of Bengal. Curr Sci 2004, 87(4), 509-15.

From temporal variations in stable isotopes, mineral magnetism, clay mineral and granulometric parameters from a ¹⁴C dated core have been used to understand weathering history and influence of climate on the terrigenous fluxes into the Bay of Bengal. We deduced well defined events of reduced fluvial influx at 20-15, 12.7, 9.5, ~ 5-4.3 and 1.8-2.2 Ka BP and at least two major fluvial pulses initiated around 11.5 and 9.5 Ka BP. The intensified monsoon regime appeared to have set in at around 9.5 Ka and had pauses at ~ t and 2.2 Ka BP during the Holecene. The climate variability appeared to have significant control over characteristics of terrigenous flux into the bay, particularly during the glaciation events. IIlite, chlorite, smectite and kaolinite are the clays present in the core. From the abundance of chlorite (the clays produced in arid cold climate) and increased contents of silt, a reduced chemical weathering during events of glaciations has been inferred. Occurrence of coarser magnetic grains in the lower levels of the cores (35-100 cm), perhaps, suggests higher magnitude of physical weathering in Pre-Holocene in the Hinterland. An intensified chemical weathering in the Himalayas, under an active summer monsoon regime after 9.5 Ka BP, appears to have enhanced fluxes of finermagnetic minerals, clay size detritus and reduced chlorite during the entire Holocene (0.30 cm levels).

3 illus, 1 table, 42 ref

003191   Chandrasekar N;Cherian A;Glory M;Subbulakshmi M (Marine Geochem Res Lab, SPIC Res Centre, V O Chidambaram Coll, Tuticorin, Tamilnadu-628 008) : Studies on fluoride level in the coastal aquatic system around the industrial zone of Tuticorin, Tamilnadu. Indian J Envir Ecoplann 2004, 8(2), 447-52.

The coastline of Tuticorin is clumped with different chemical industries. The focal source of fluoride intake in human and animal system is water and food having high levels of fluoride. The main anthropogenic sources for fluoride in the aquatic systems are from manufacturing hydrofluoride acid, super phosphate, enamel paints, bricks, thermal power plant, etc. The surface water and groundwater of the industrial belts of Tuticorin coast has been collected to assess the level of fluoride content in conjuction with other parameters. The fluoride content in the groundwater ranges from 0.43 mg/l to 1.29 mg/l whereas in the surface water from 1.23 to 1.94 mg/l. The fluoride content has a direct relationship with Ca, Mg, No₃^-, total alkalinity and total hardness. A positive correlation between fluoride Vs total alkalinity and a negative correlation between fluoride Vs calcium and fluoride Vs nitrate in groundwater as observed. Conversely, fluoride displays a negative correlation with magnesium and positive correlation with calciu, total hardness and total alkalinity in the surface water. The negative correlation reveals the source of fluoride, mainly from anthropogenic effects.

2 tables, 8 ref

003190   Bajpai S;Kapur V V (Earth Sci Dep, Indian Inst of Technol, Roorkee-247 667) : Oldest known gobiids from vastan lignite mine (early eocene), Surat District, Gujarat. Curr Sci 2004, 87(4), 433-5.

2 illus, 7 ref

003189   Bahrat Singh;Gajja B L (Reg Res Station, Central Arid Zone Res Inst, Bikaner-334 006) : Labor decomposition analysis under new technology of legume crops in arid zone of Rajasthan. Ann Arid Zone 2003, 42(1), 79-84.

002194   Vijaya Rao V;Rajendra Prasad B;Tewari H C (Nat Geophys Res Inst, , Hyderabad) : Integrated geological and geophysical studies - examples from Indian shield. J Geophys 2004, 25(4), 79-85.

The need for using different geophysical methods in deriving the subsurface structure of a region, in the light of their advantages and limitations is discussed. Integrated studies are essential in hydrocarbon exploration as well as in crustal studies, even though the data sets involved may be different. results from the integrated geological, geophysical and geochemical/geochronological studies from the Aravalli-Delhi fold belt and the Central Indian Shear zone are presented. An integrated study provides the necessary link between surface geology and the subsurface through geophysics and effectively bridges the gaps between different disciplies of earth science. As multi-parametric and multi-disciplinary approach has proven advantageous and is most likely to succeed, the future of geosciences lies in integrated studies.

5 illus, 14 ref

002193   Singh V K (Slope Stability Div, CMRI, Dhanbad, Jharkhand) : Correlation between point load index and compressive strength for quartzite rocks. Indian Min Engng J 2004, 43(8-9), 20-1.

The point load test is widely used to determine the uniaxial compressive strength indirectly because of its ease of testing, simplicity of sample preparation and possible field application. Widely used correlations, between point load index and other geotechnical parameters exist. However, more experimental work helps to substantiate the existing correlations. NX size core sample of quartizites from an open pit in Rajasthan State of India were used for testing. The sample preparation and testing procedure were in accordance with ISRM (1981). Based on the study the ratio between uniaxial compressive strength and point load for the quartzites of the copper mine is 23.37.

2 illus, 2 tables, 7 ref

002192   Singh a K;Singh R K B;Vallinayagam G (Earth Sci Dep, Kurukshetra Univ, Kurukshetra-136 119) : Petrochemical characteristics of basalt from Kundal area, malaniigneous suite, West Rajasthan, India. Indian Mineralogist 2004, 38(2), 1-11.

Basalt flows associated with porphyritic rhyolite are reported from Kundal area of Malani Igneous suite. Basalt is fine grained and displays subophitic and glomeroporphyritic textures. It essentially consists of plagioclase feldspar and augit. Presence of basalt xenoliths in the rhyolite suggest that basalt is older than rhyolite. Geochemical characteristics indicate that these basalts are alkali basalt, an anorogenic setting for their emplacement. The parental magma appears to have results from a sub-continental lithosphere mantle source with Fe/Mg ratio exceeding that of pyrolite source.

6 illus, 2 tables, 22 ref

002191   Sen S (NO, Council of Scientific and Industrial Res, Plot 10, Puranik Layout, Bharat Nagar, Nagpur-440 001) : Unified global tectonics: structure and dynamics of the total earth system. J Mines Metals Fuels 2003, 51(11-12), 351-5.

A new expansion-oriented global tectonics, developed by the author envisages that during the primordial pre-expansion stage of the earth, its crustal surface was devoid of ocean bodies. Hence, it can be rationally conceived that the large quantum of ocean-forming water was originally associated with the mantle, thereby rendering that medium considerably fluid and preeminently suitable for manifestaion of expansion and other mobilistic activities. Under such a set up expansion of the planet appears to have been caused by tidal bulging of the semi-fluid mantle due to which a number of expansion cracks were developed over the solid sialic crust. Through these cracks, which subsequently turned into mid-oceanic ridges, widespread basaltic lava extruded froming the floors of the rudimentary ocean basins. With continued gradual expansion of the planet, the fragmented continental blocks were laterally segregated causing enlargement of the ocean basins formed in the intervening space. Side by side, due to the accompanying process of degassing of volatiles, chiefly composed of water vapour, the evolving ocean basins were filled up with water while the mantle itself, due to seggregation of water, gradually turned into a solid and rigid geosphere. In the interior of the planet it has been conceived that before expansion, the fluid outer core was not developed and consequently. The primordial semi-fluid mantle and the solid inner core were initially juxtaposed to each other. It was due to the radial expansion of the planet, the original core-mantle conjunction was ruptured and along the ruptured surface, a void or non-solid zone was gradually developed. Due to the influx of fragmentary particles and masses from the adjoining walls, the void zone in due course assumed a pseudo-fluid characteristic and can be readily identified as the planet's fluid outer core. Such disposition of two discrete solid geospheres, separated by a non-solid or virtually void zone, would give rise to a reversely directed force of gravity in the interior of the planet, bringing forth a low pressure zone with temperature sufficiently below the Curie point of iron or nickel around the solid core.

2 illus, 17 ref

002190   Sarma S V S;Harinarayana T;Virupakshi G; Someswara Rao M;Madhusudan Rao;Nagarajan N;Sastry T S;Rao S P E (Natnl Geophys Res Inst, , Uppal Road, Hyderabad) : Magnetotelluric investigations in Deccan trap covered areas of Nagpur-Wardha region, India. J Geophys 2004, 25(4), 87-91.

In the context of the efforts for identification and evaluation of hydrocarbon potential of different basins in the country, Nagpur-Wardha is an important region in central India covered by Deccan volvanics. New directions in the exploration strategies need to be evolved to investigate the difficult and complex areas using judicious combination of conventional as well as non-conventional techniques like Magnetotellurics (MT) and other deep electromagnetic methods. With the support of Directorate General of Hydrocarbons (DGH), National Geophysical Research Institute (NGRI) has taken a lead in this direction to the application of MT, which is one of the most effective techniques, particularly in investigating areas covered by volcanics. This is because the target layer, a subtrappean Gondwana sedimentary column, in general has a marked resistivity contrast with the underlain basement as also to the overlying volcanic cover. The results of MT studies have demarcated the area of interest from the viewpoint of thick sediments, i.e.3-4km, in the region around Katol and Kondhali areas. The efficacy of the approach in the estimation of the thickness of volvanic cover subtrappen sediments and also the regional tectonics of northwest extension of Pranahita-Godavari garben have been discussed.

4 illus, 12 rer

002189   Sankaran A V (NO, , No. 10, P and T Colony, I Cross, II Block, RT Nagar, Bangalore-560 032) : Oxidation of iron sans oxygen fungacity: fresh insights from lower mantle mineral chemistry. Curr Sci 2004, 87(5), 555-6.

26 ref

002188   Roy S C (NO, , 2/133, Vikas Nagar, Lucknow) : Isolation of the geological community. Curr Sci 2004, 87(5), 553.

^ssc2 ref

002187   Ramesh D S (National Geophysical Res Inst, , Hyderabad-500 007) : On the efficacy of recent crustal images of the Indian shield from receiver functions. Curr Sci 2004, 87(5), 573-82.

6 illus, 29 ref

002186   Prasada Rao P;Rajput S;Sridhar A R;Thakur N K;Reddi S I (Gas Hydrate Group, National Geophysical Res Inst, Hyderabad-500 007) : Model studies of ocean bottom seismometer experiment for gas-hydrate exploration. Curr Sci 2004, 87(5), 667-73.

Models the P- and S-wave velocities of gas hydrates and free gas-bearing sediments and obtains the traveltime response for sutiably spaced ocean bottom seismo meters (OBS) on sea floor. The different models are presented with contrasting physical properties which produce the travel time curves corresponding to the gas hydrate and free gas layers for varyign source receiver offsets of the OBS. 2D ray tracing is done on models of different configuration, i.e. varyign depths of sea floor, gas hydratte zone (GHZ) and free gas zone (FGZ) with the same sediment thickness. The best representative model is selected for each case, which produces the significant ray bending and travel time skips at contrasting velocity horizons of gas hydrate bearing sediment layer underlain by significantly low velocity layer of free gas. The results indicate that OBS should be deployed at a minimum of 5 km separation for getting better travel time response for GHZ and FEZ. The exercise aims to provide some synthetic data and could be useful in deriving a physical model and in planning future OBS experiments for gas-hydrage exploration.

6 illus, 19 ref

002185   Pal D C (Geological Sci Dep, Jadavpur Univ, Kolkata-700 032) : Concentric rings of radioactive halo in chlorite, Turamdih uranium deposit, Singhbhum zhear sone, Eastern India: a possible result of <. Curr Sci 2004, 87(5), 662-7.

Transmitted light microscopy of quartz-chlorite schist from Turamdih uranium deposit in Singhbhum shear Zone has revealed the presence of distinctly circular aureoles of radiation damage, commonly referred to as radioactive halos or radiohalos, in chlorite surrounding inclusions of uraninite in teh Turamdih uraniumore; particularly those surrounding tiny (<60>2μm) radio centres show spectacular concentric aureoles. In well developed halos, four distinct rings of discoloration are clearly visible in host chlorite. The radiohalo pattern is in good agreement iwht the theoretical radiohalo pattern is in good agreement with the theoretical radiohalo pattern of ²³⁸U based on α-penetration ranges in air. Radii of individual rings surrounding tiny radiocentres (<60> 2 μm) in diametral/near-diametral section are consistent and the mean radii of 32.4 <109>M (outermost), 22.0, 18.3 and 15.2 <109>m (innermost) compare well with the experimentally determined, theoretically calculated and observed penetration depths of α-particles emitted by ²¹⁴Po (the outermost ring), ^218>Po, ²¹⁰Po/²²²Rn and ²²⁶Ra/²³⁴U/²³⁰Th (innermost ring) in biotite. Such ring structures can be assigned to the decay chain of ²³⁸U in which the above radioactive atoms correspond to daughters in the decay series and each of them emits <97>-particles of different energies. The undeformed circular nature of the radiohalos is indicative of their postkinematic origin. Petrographic studis also indicate possible mobilization of uranium by some later processes.

5 illus, 1 tables, 15 ref

002184   Padhy S (Seismological Observatory, National Geophysical Res Inst, Uppal Road, Hyderabad-500 007) : Rescaled range fractal analysis of a seismogram for identification of signals from an earthquake. Curr Sci 2004, 87(5), 637-41.

The recognition of seismic signals from the background random noise and identification of various phases in a seismogram are studied from the variation in fractal dimension, D, obtained from Hurst's R/S rescaled range analysis of seismograms. A rapid change in fractal dimension occurs with change in seismic attributes in a seismogram, although the nature of change varies from trace to trace with varying signal to noise ratio and with varying frequencies. the approach is based on the fact that noise has higher fractal dimension than the seismic signals. This method, when applied to the earthquakes in Bhuj and Koyna region of peninsular India, explains the origin of the complexities of the observed waveform, interpreted in terms of degree of heterogeneities of the lithosphere from the variance fractal dimension. The above findings are supported by previous studies of frequency dependence of seismic wave attenuation in the region.

3 illus, 25 ref

002183   Mondal N c;Singh V S (National Geophysical Res Inst, , Hyderabad-500 007) : A new approach to delineate the groundwater recharge zone in hard rock terrain. Curr Sci 2004, 87(5), 658-62.

Delineation of potential groundwater reacharge zone is vital to augment groundwater resources in hard rock terrain. It is also important for the sustainable development and management of groundwater resources. Conventionally, suitable zone for potential groundwater recharge in deciphered using tritium injection, hydrogeologica, geophysical geomorphological maps and regional groundwater model, which are often time consuming and uneconomical. Therefore, the analysis of unconfined aquifer response in terms of rise in water level due to precipitation, a rapid and cost-effective procedure is evolved in hard rock terrain. cross correlation of rise in water level and precipitation is established. The entire area is classified into various zones depending on variability in coefficient of correlation. Thus, most favourable zone for artificial recharge is delineated with the help of correlation coefficients, which has given good agreement with the results of Remote Sensing (RS) and Geographical Information System (GIS) technique in the study area.

6 illus, 2 tables, 14 ref

002182   Mishra D;Bhattacharya D K;Barla V C (NO, , 146/E, Pandey Niwas, Morabadi, Ranchi-834 008, Jharkhand) : Occurrence of peridotitic komathte in the chotanagpur gneisses around semra, South of Daltonganj, Palamau District, Jharkhand. Indian Mineralogist 2004, 38(2), 12-9.

A preliminary account of the petrology and geochemistry of the hitherto unreported Spinifex Textured Peridotitic Komatiite (STPK) occurring around Semra, South of Daltonganj in the Chotanagpur Gneiss-Granulite Complex has been presented in this paper. Field evidences suggest possible fracture controlled tectonic emplacement of these rocks. The rock is composed mainly of olivine (slightly altered to antigorite and chlorite), augite, opaques, and devitrified glass. Geochemically, the rock has high MgO (22.20-29.11 wt. %), Fe₂O₃ (17.31-21.11 wt%), Al₂O₃ (7.03-8.80 wt. %), Ni (750-1925 ppm), Cr (2800-3400 ppm) and low TiO₂ (0.33-0.48 wt. %), Na₂O (0.12-0.32 wt.%), K₂O (0.11-0.23 wt.. %), Y (4-12 ppm), Rb (1-5 ppm), Ba (1.8-5.0 ppm) and Nb (1-3 ppm) contents. These rocks may be contemporaneous with high Mg komatiitic rocks of Dalma volcanics of Singhbhum of Mesoproterozoic age.

6 illus, 1 table, 15 ref

002181   Menon H B (Marine Sci Dep, Goa Univ, Taleigao Plateau, Goa-403 206) : Calibration of an optical equation to analyse the atmospheric turbidity and water quality of an estuarine environment. J Indian Soc Remote Sens 2004, 32(3), 287-300.

Mapping of oceanic productive zones through an optical sensor on board a satellite requires a detailed knowledge about the interaction of solar flux with the atmosphere and water column. Hence the radiative transfer on February 14, 2002 over estuaries of Goa has been examined through a couple radiative transfer model (CRTM). This has been carried out in the context of an optical sensor when it looks down at nadir. The forcing of extraterrestrial solar irradiance with atmosphere results in its absorption and scattering due to aerosol particles and gaseous constituents and Rayleigh particles. The oopical spectrum has been subjected to atmospheric forcing and radiation has been calculated for every 1 nm. Special reference is given to two wavelengths (443 and 510 nm), which are important for ocean optics. the atmospheric components pertaining to these wavelengths are 0.04193 w/m²/nm/sr (aerosol). Within the optical frame work (400 - 700 nm), the effect of aerosol overrides that of Rayleigh from 545 nm onwards. The specular reflectance at the sea surface contributes 1.725 x 10^-12 w/m²/nm/sr and 1.947 x 10^-12w/m²/nm/sr while respective signature from water column is 0.418 x 10^-3 w/m²/nm/sr and 0.536 x 10^-3 w/m²/nm/sr. The simulated water signature has been compared with radiances measured by a radiometer (Satlantic radiometer). the correlation (R²) is found to be around 0.97. The sensitivity analysis further reveals the respective wavelengths of the optical spectrum affected by atmospheric and oceanic constituents. Moreover, the effect of change in solar zenith angle on water signature has also been carried out. This could be applied to invert satellite data so as to retrieve coastal water constituents and productivity.

10 illus, 1 table, 30 ref

002180   Lakshmipathaiah H K;Govindaiah S (Geology Dep, Bangalore Inst of Technol, V V Puram, Bangalore-560 004) : Textures and chemistry of chromite ores of Shivani ultramafic complex of Shimoga schist Belt, India. Indian Mineralogist 2004, 38(2), 46-59.

The Shivani ultramafic complex has been emplaced into the Peninsular gneissic complex in the southern boundary of Shimoga schist belt of Dharwar craton. This complex consists of dunite, peridotite and pyroxenite with layers of textures like cumulus, clot, zoned clot, occluded silicate and intergrowth textures that the developed by magmatic differentiation and gravity settling process. Chemistry of chromites exhibits features typical of stratiform igneous complexes. The ores have been subjected to deformation as a result, secondary textures are developed. Temperature estimates made based on olivine-chromite geothermometer ranges from 460 to 500°C and pressures ranging from 2 to 3 Kbars, which is in agreement with the temperatures calculated based on the metamorphic mineral assemblages-antigorite-talc-carbonate indicating lower ambhibolite grade metamorphism. Chromite shows zonation in which parent chromite core is mantled by ferritchromit which in turn is rimmed by magnetite. Development of this zonation is a replacement process which has taken place during serpentinization in the lower amphibolite grade metamorphism.

9 illus, 2 tables, 29 ref

002179   Kripalani R H;Kulkarni A;Sabade S S;Revadekar J V;Patwardhan S K;Kulkarni J R (Indian Institute of Tropical Meteorology, , Pashan, Pune-411 008) : Intra-seasonal oscillations during monsoon 2002 and 2003. Curr Sci 2004, 87(3), 325-31.

Features of the intra-seasonal oscillations during monsoon 2002, a drought year, and monsoon 2003, a normal year, have been examined by applying a frequency filter and the technique of wavelet analysis to rainfall data. Analysis reveals that while the faster 10-20 days mode dominated mansoon 2003, the slower 30-60 days mode dominated monsoon 2002.

9 illus, 1 table, 31 ref

002178   Kotlia B S;Rawat K S (Geology Dep, Kumaun Univ, Nainital-263 002) : Soft sediment deformation structures in the garbyang palaeolake: evidence for the past shaking events in the Kumaun tethys Himalaya. Curr Sci 2004, 87(3), 377-9.

Soft sediment deformation structures are observed in the laminated sediments and sandy part of the 150 m thick palaeolake profile exposed along the Chhidu Nala near Garbyang village in the Tethys zone of Kumaun Himalaya. The deformed, laminated sediments and sand are separated by gravel. Observes both penecontemporaneous and post-depositional deformational patterns. The deformation may have taken place due to thixotropy and fluidization causing visco-plastic failure of the mud, and density inversion between mud and sand due to liquefaction, was probably triggered by earthquakes. This gave rise to soft sediment folds, dykes, faults, load and pseudo-nodule structures in mud, silt and sand. The study area lies in the seismically active zone of the Kumaun Himalaya.

5 illus, 24 ref

002177   Khosla A;Prasad G V R;Verma O;Jain A K;Sahni A (CAS in Geology, Panjab Univ, Chandigarh-160 014) : Discovery of micromammal-yielding Deccan intertrappean site near Kisalpuri, Dindori District, Madhya Pradesh. Curr Sci 2004, 87(3), 380-3.

An intertrappean section exposed along the right bank of Kharmer river near Kisalpuri village (Dindori District) in Madhya Pradesh has yielded a rich microvertebrate assemblage. This assemblage consists of fishes: Igdabatis indicus, Lepisosteus cf. L. indicus, Pyconodontiformes, Osteoglossiformes, Siluriformes; anurans: Leptodactylidae gen. et sp. indet.: squamates: indeterminate lizards, Serpentes indet., Bothremydidae group of chelonians, neosuchian crocodiles, sauropod, ornithoid, and theropod dinosaur egg-shell fragments and an eutherian mammal. This is one among the few mammal-yielding Late Cretaceous sites reported so far from India. Preliminary study of a single mammalian lower molar indicates a close affinity to the Laurasian boreosphenidan eutherians.

3 illus, 32 ref

002176   Kannan S;Mallick K (Natnl Geophy res Inst, , Hyderabad) : Finite element approach for resolution of regional residual gravity anomalies. J Geophys 2004, 25(4), 101-4.

The regional - residual separation of the Bouguer gravity field is an important step for the interpretation of the gravity anomalies. Starting from the intuitive graphical smoothing technique a variety of analytical techniques, both in spatial and frequency-domain, has been developed in the past six decades. A space-domain analytical technique, based on finite element approach, the performs very satisfactorily to derive the regional and residual components has been descussed. To provide field examples, this technique is applied to the Bouguer gravity fields of the Reguba oil field in Libya and northwest Ontario in Canada to obtain more precise regional and residual components.

3 illus, 6 ref

002175   Jagadeeswara Rao P;Harikrishna P;Suryaprakasa Rao B (Geo Engng Dep, Andhra Univ, Visakhapatnam-530 003) : An integrated study on ground water resource of pedda gedda watershed. J Indian Soc Remote Sens 2004, 32(3), 307-11.

^ssc1 illus, 1 table, 12 ref

002174   Gil-Alana L A (Univ of Navarre, , Campus Univ, Faculty of Economics, Edificio Biblioteca, Entrada Este, E-31080 Pamploma, Spain) : A fractionally integrated model for some Indian monthly rainfall data. J Indian Inst Sci 2004, 84(1-2), 1-20.

Some Indian monthly meteorological data have been examined by means of fractional integration. The results show that long memory is present in the monthly structure of various rainfall data. Moreover, they are homogeneous across the regions, with the values of d ranging between 0.25 and 0.75. Attempting to summarize the conclusions for the individual months, the degree of dependence between the observations during May-September seems to be higher than for the remaining months.

5 illus, 5 tables, 66 ref

002173   George A V (Geology and Envirn Sci Dep, Christ Coll, Irinjalakuda) : Microstructural analysis of quartz C-axis orientation from Polur area, Thiruvannamalai District, Tamilnadu, South India. Indian Mineralogist 2004, 38(2), 39-45.

Results of micro structural analysis of quartz c-axis orientation from different lithi units to investigate the possible correlation fo the componental movements in the rocks, with various deformation phases are presented. Detailed studies have shown that the resultant fabric of the area under investigation is the results of the domination of two glide systems - the trigonal dypyramid (2112) and the prism (1010) system during deformation as observed in teh Padagam Kommandal region of the study area.

22 illus, 18 ref

002172   Binu K S;Prakasam V R (Environmental Sciences Dep, University of Kerala, Thiruvananthapuram 695 581) : Characterization of springs and wells of Varkala Kerala. Envir Ecol 2003, 21(3), 662-3.

Verkala in Kerala is famous as an international tourist spot. People of the area depend on well water and spring water for drinking and domestic purposes. To assess the quality of these water sources, water samples were collected during the tourist season- January to May 2002 and evaluated for its potability. The results showed that with respect to most of the consituents except pH The water samples satisfy the requirements set by Bureau of Indian standards.

002171   Basavarajappa H T;Narasimha K N P;Srikantappa C (Studies in Geology Dep, Univ of Mysore, Manasagangothri, Mysore-6) : Petrochemical characteristics of archaean metasediments from the biligirirangan granulite terrain, Dharwar craton South India. Indian Mineralogist 2004, 38(2), 25-38.

Granulites are important constituents of the middle to lower crust. Metasedimentary rocks such as Banded Magnetite Quartzite - Mn rich metasediments (qtz+magnetite+opx +/- garnet), Pelites (silli + grt + stau and bio ± corundum; plagio + grt + bio + opx +corundum) and calc-silicate (cal + grt-gr rich - grt + scap + hbl + ca-plagio) occur, forming part of the Biligirirangan granulites and the amphibolite facies gneissic terrain in southern part of the Dharwar Craton. Both in terms of major and trace elements geochemistry, the meta sediments indicate their precursors to be sediments, despite strong deformation and high-grade meta morphism. The chemistry of the metasediments of Biligirirangan granulites are comparable to the meta sediments of older Srgur group of rocks (<62> 3.0 Ga) in the Dharwar Craton and indicate to their deposition under epicontinental platform/shelf environment under shallow water and stable tectonic conditions. They represent proto-surperior type sediments.

5 illus, 2 tables, 29 ref

002170   Basavalingu B;Ganesha A V (Studies in Geology Dep, Manasagangotri, Univ of Mysore, Mysore-570 006) : Formation of high cordierite in kmash system-an experimentals study in relevnce to mg-Al granulites. Indian Mineralogist 2004, 38(2), 65-74.

3 illus, 2 tables, 23 ref

001210   Tyagi A;Sharma M K;Bhatia K K S (NO, National Institute of Hydrology, Roorkee 247 667) : The study of temporal and spatial trends of water quality of river Kshipra using water quality index. Indian J envir Hlth 2003, 45(1), 15-20.

Water quality index (WQI) plays an important role in interpreting the information on water quality trends of a water body. An attempt has been made to study the spatial and temporal water quality trends of one of the pristine river Kshipra (Madhya Pradesh) using water quality index. The importance of existing sampling sites has also been discussed.

3 illus, 1 tables, 17 ref

001209   Thorndycraft V R;Benito G;Rico M;Sopena A; Sanchez-Moya Y;Casas A (Centro de Ciencias Medioambientales-CSIC, , Serrano 115 bis, 28006 Madrid, Spain) : A late holocene palaeoflood record from slackwater flood deposits of the Llobregat river, NE Spain. J Geol Soc India 2004, 64(4), 549-59.

The palaeofloods of the Llobregat River are the first to be reconstructed for a Spanish Mediterranean river basin. In total, 56 individual slackwater flood units were identified in eight valley-side alcoves located along two study reaches, Pont de Vilomara and Monistrol de Montserat. The majority of the deposits are fine sands or very fine sandy silts, with a variety of sedimentary structures identified, namely parallel laminations, climbing ripples (both-in-phase and in-drift) and current ripples. The estimation of the palaeoflood discharges associated with these deposits, using the HEC-RAS one-dimensional hydraulic model, has provided long-term data regarding flood magnitude within the catchment. Palaeofloods at Pont de Vilomara, radiocarbon dated to 2640±55 yrs BP and 2580±75 yrs BP, have minium estimated discharges of 3700-4300 m³s¹. The results indicate that the instrumental discharge series is of insufficient length to have witnessed the largest magnitude flood events within the Llobregat catchment and that the use of palaeoflood hydrology is a valuable means of improving the flood record of Mediterranean catchments.

7 illus, 3 tables, 46 ref

001208   Suresh KUmar M;Vaidya A N;Shivaraman N;Bal A S (National Environmental Engineering Research Institute, , Nehru Marg, Nagpur 440 020) : Performance evaluation of a full-scale coke oven wastewater treatment plant in an integrated stel plant. Indian J envir Hlth 2003, 45(1), 29-38.

Wastewater generated during coke-oven gas cleaning operations in the integrated steel plan contains phenol, cyanide, thiocyanate, and also oil and grease. Although the activated sludge process is widely practiced for biological treatment of coke-oven wastewater, it was observed during the evaluation of performance of full scale coke-oven wastewater treatment plant that oil contamination and poor sludge settleability had resulted in poor maintenance of the activated sludge process. Keeping these aspects in view, treatability studies were conducted and an alternative treatment plant will give desired performance. Present Results of the performance evaluation, data on treatablity studies and alternative treatment process scheme have been presented.

8 illus, 7 tables, 1 ref

001207   Sud Y C;Walker G K (Climate and Radiation Branch, Laboratory for Atmospheres, NASA/GSFC Greenbelt, MD 20771, USA, ) : New upgrades to the microphysics and thermodynamics of clouds in McRAS: ACM and GCM evaluation of simulation biases in GEOS GCM. Proc Indian Natn Sci Acad-Pt A 2003, 69(5), 543-65.

Reports that since model simulations represent the integrated influence of all component-parameterizations, true impact of any model upgrade can be isolated only after the model has been returned to exhibit radiative forcings similar to or better than that of the Control simulation. This kind of research is central for improving and understanding the behaviour of cloud processes in GCMs.

10 illus, 46 ref

001206   Starkel L (Department of Geomorphology and Hydrology, Institute of Geography, Polish Academy of Sciences, 31-018 Krakow, sw.Jana 22, Poland) : Temporal clustering of extreme rainfall events in relief transformation. J Geol Soc India 2004, 64(4), 517-23.

Deals with extreme rainfall events, which are responsible for the transformation of slope and fluvial systems, and the clustering of the events in time. Several types of extreme rainfall events have been identified. Especially interesting and consequential events are those that have characteristics of more than one type. It is observed that the frequency and recurrence interval of such events depend upon the climatic zonality as well as on the relaxation time of the disturbed system. The focus of this paper is on short-time events (1-3 years of less), which provide litle or no time for relaxation to the slope and fluvial systems. Clusters including rare events are separated by longer periods. In the case of Cherrapunji the discussion relates to high frequency rainfall events rather than their clustering. Several examples of clustering are discussed in this paper. The response of slope or the channel systems to such clustering of extreme events is in the form of a new equilibrium condition. Such systems either show a tendency towards rejuvenation or a trend towards accelerated maturation. However, other factors such as rock resistance and neotectonic activity are also important and modify this picture. Historical and geological records provide evidence of such clustering of extreme events, especially during the Holocene phases with higher frequency like the Little Ice Age.

7 illus, 30 ref

001205   Sreedevi P D (National Geophysical Research Institute, , Hyderabad-500 007) : Groundwater quality of Pageru river basin Cuddapah district, Andhra Pradesh. J Geol Soc India 2004, 64(5), 619-36.

The study was undertaken to assess the water quality in relation to agricultural and domestic uses in parts of Pageru river basin, Andhra Pradesh. The rock formation of study area is Cuddapah Supergroup and Kurnool Group. The important lithounits consist chiefly of quartzite, limestone and shale. The results of chemical analyses of ninety-nine water samples were collected from bore wells. The quality analysis is made through the estimation of silica, calcium, magnesium, sodium , potassium, carbonate, bicarbonate, sulphate, chloride, total dissolved solids, Hydrogen ion concentration(pH) and specific conductance. Based on the analyses, certain parameters like non-carbonate hardness, sodium adsorption ratio, potential salinity, residual sodium carbonate, Kelly's ratio, magnesium ratio, index of base exchange and permeability were calculated. From the evaluation, it is known that the water quality is suitable for both domestic and irrigation purposes. According to Gibb's diagram all the samples in both the seasons fall in the rock dominance field. Assessment of water samples from various methods proved that majority of the water samples are good either for drinking or for agriculture in both seasons. The overall quality of waters in the study area in post-monsoon season in all constituents are high because of rock-water interaction and rules out any pollution from extraneous sources.

12 illus, 10 tables, 28 ref

001204   Sinha R;Stueben D;Berner Z (Engineering Geosciences Group, Indian Institute of Technology, Kanpur-208 016) : Palaeohydrology of the Sambhar Playa, thar Desert, India, using geomorphological and sedimentological evidences. J Geol Soc India 2004, 64(4), 419-30.

The Sambhar Playa in western Rajasthan, India has been studied to understand its tectono-geomorphologic evolution and palaeohydrological reconstruction. The playa basin originated due to tectonic movements during the Quaternary, and was deepened by large scale deflation during arid priods. A dense network of relict drainage reflects abundant supply of water and sediments during wetter phases. A deep core (~23 m) raised from the center of the playa indicates an alternation of clastic and evaporitic sediments. Mineralogical assemblages and the geochemical characteristics have been used to decipher the palaeohydrological conditlions in the region for a period extending over 25 ka. Evaporie mineralogy shows a major change in brine chemistry at ~5 m depth, the lower part being rich in gypsum and the upper part completely devoid in gypsum. The vertical profile shows a correlation between Na/Al ratio, δ¹⁸O values of carbonates, MgO/(MgO+CaO) ratio of insoluble fraction and dolomite content. We interpret these trends as changes in evaporation/inflow ratio which in turn would reflect low/high stands of the lake.

6 illus, 1 tables, 55 ref

001203   Singh I B (Department of Geology, Lucknow University, Lucknow-226 007) : Late quaternary history of the Ganga plain. J Geol Soc India 2004, 64(4), 431-54.

Flexural subsidence of the Indian lithosphere created the Ganga Plain foreland basin in front of the Himalayan orogen, which attained its present configuration during the late Quaternary. Climate change, neotectonics and base level changes influenced the evolution of the present landforms of the Ganga Plain. The regional geomorphic surfaces are: Upland Interfluve Surface (T₂); Marginal Plain Upland Surface (MP); Megafan Surface (MF); Piedmont Fan Surface (PF); River Valley Terrace Surface (T₁) and Active Flood plain Surface (T_o). The Upland Interfluve Surface (T₂) is widespread reference surface; other surfaces are either incised or overlie this surface. Formation of these surfaces is essentially related to the climate cycles of late Pleistocene-Holocene (128 ka BP). These surfaces are depositional and have a succession of overlying sediments, younger than the time of formation of the respective surfaces. The sediments coming from the Himalaya undergo significant chemical weathering in the alluvial plain where much Na, Ca, Sr, K, Mg is removed; while As, Cr, Ni and Th are enriched. In suitable conditions smectite and kaolinite are formed. These sediments are partly eroded and transported to the delta region and beyond. The Ganga Plain consists of a large number of river systems; originating in different parts of the Himalaya, Peninsular Craton, and alluvial plain formed at different times during the late Pleistocene-Holocene. Surface runoff and groundwater are the main sources of water. It is difficult to make meaningful scheme of classification of channels. Based on the sediment-water transfer patterns, the channels are classified into three broad categories. The river systems are in different stages of evolution. The active perennial rivers are incised within the alluvium, and show avulsion on a scale of 10⁴-10⁵ years; some channels, part of the ancient anastomosing network, act as flood channels and show avulsion on a scale of 10¹-10² years. The Upland Interfluve Surface (T₂) exhibits a number of microgeomorphic features which have helped in the reconstruction of the history of the Ganga Plain during the last ~20 ka BP: 20-13 ka BP-new drainage of low density; 13-8 ka BP-extension of drainage system, high rainfall; 8-6 ka BP -channel disruption due to base-level rise and tectonics and formation of large lakes which retained most water-sediment of T₂-Surface; 6-4 ka BP - dry climate, increased terigenous clastic sediments in lakes; 4-2 ka BP- increased siltation of the lakes, moderate rainfall; 2-0 ka BP- fragmentation and drying of lakes, strong anthropogenic influence. The basin exhibits active tectonism, which is mostly in the form of contractional system in the piedmont zone, and prominent extensional system in the southern part of the basin. One of themsot significant events in Ganga Plain history is tectonics of 8-5 ka BP, which produced areas of centripetal drainages and changed the fluvial landscape into a landscape of ponds and lakes with few high grounds. It was helped by the climate change from humid to dry around 5 ka BP.

17 illus, 82 ref

001202   Sikka D R (NO, , 40, Mausam Vihar, Delhi-110 051) : Evaluation of monitoring and forecasting of summer monsoon over India and a review of monsoon drought of 2002. Proc Indian Natn Sci Acad-Pt A 2003, 69(5), 479-504.

Discusses the operational monitoring of the day-to-day and seasonal monsoon (June-September) rains over India which helped IMD inform the policy makers and the general public by the end of July 2002 itself about the impending drought. The system used for Long Range Forecasting of monsoon season rainfall over India and its limitations for forecasting an extreme monsoon season are discussed. Monsoon 2002 failed because of the unprecedented deficit of rainfall in July 2002, though in the other three months of the season, the performance of the monsoon was within normal fluctuation regime. Regional and global scale feature of the atmosphere ocean system during June to September 2002 are examined to diagnose the factors which could have contributed to the monsoon drought of 2002. The study concludes that evolving response and feed-back processes and response of the monsoon system for the prevailing circulation features over the mid-latitudes of Eurasia and the South Indian Ocean as well as persistent negative phase of SOI and warmer SST from South China Sea to 160°E and evolution of SST warming over Nino-3 and 4 region in July-August could have caused the drought over India. These features evolved as the season progressed as such prior forecasting on long-range basis was not possible.

10 illus, 35 ref

001201   Shukla U K;Singh I B (Department of Geology, Kumaun University, Naintal-263 002) : Signatures of palaeofloods in Sandbar-levee deposits, Ganga plain, India. J Geol Soc India 2004, 64(4), 455-60.

Based on architectural element analysis of Sandbar-levee deposits an attempt has been made to identify recurring floods in the alluvial rivers. Point bar deposits characterized by low-angled lateral accretion (LA) elements exhibit some channel-ward steeply dipping (18-20°) discordant surfaces. These high-angled surfaces are erosional and show change of facies across them. Such discordant planes present within the point bar deposits most probably indicate phases of exceptional floods, when the bar was mostly eroded and remodelled under high-energy conditions. Similarly, in the braid bar deposits superimposed bar-building events separated either by mud drapes of marked erosional contacts are testimony to high-energy floods. At flood times, a new bar may form and can migrate over pre-existing sand bar, forming huge sandflat. Alternatively, a new channel may develop cutting across the existing bar complex producing a channel bar having a different orientation. Multi-storied levee deposits developed at the bank of the channels, and characterized by decimeter to meter scale fining-up sequences, are the best indicators of exceptionally large floods overtopping the channels. The flood events are commonly separated by erosional contacts and mottled horizons containing organic matter, root burrows and faecal-pellet filled earthworm burrow network.

4 illus, 16 ref

001200   Shrivastava S K;Nambiar K V;Gaur V P (Geological Survey of India, , Operation Madhya Pradesh, Bhopal) : Orbicular structures in Bundelkhand granitoid complex near Pichhore, Shivpuri District, Madhya Pradesh. J Geol Soc India 2004, 64(5), 677-84.

The paper records the occurrence of large sized proto, single shell and multi-shell orbicular structures from the Bundelkhand Granitoid Complex. The orbicular structures are developed in an aplitic granite traversing the coarse grained pink granite exposed to the SSW of village Kutawali (24°07'45":78°10'20") in Pichhore Tehsil of Shivpuri district, Madhya Pradesh. The core and matrix of the orbicules have identical composition and hence the orbicular structures are classified under Homo-thrausmatic and Iso-thrausmatic category. The chemical analyses of the orbicular rocks plot in the quartz monzonite field in Na₂O-K₂O and K₂O-Na₂O-CaO diagram. The composition of the orbicules represents a felsic parentage. Perthitic integrowth points to the igneous origion of the orbicular structures.

7 illus, 1 table, 17 ref

001199   Seshadri K S;Raj S S;Lal K B (Centralised Waste Management Facility, Bhabha Atomic Research Centre, Kalpakkam, Tamil Nadu 603 102) : Spent ion exchange resin-its treatment from the point of view of safe disposal. Indian J envir Hlth 2003, 45(1), 21-4.

Ion exchange process is one of the treatment methods for radioactive waste. The resin becomes no longer useful after number of cycles of usage. At the same time the regenerated resin cannot be considered as non active waste for disposal. Hence it is felt necessary that the regenerated resin is treated in a fashion so as the result in a form which can be considered as inactive material. It is possible to convert this spent resin into multivalent ionic form which are generally non leachable, thus providing the necessary properties for meeting the disposal criteria. Studies were carried out for the exchange of radioactive ions on these resins with ions like Al³⁺, Sn⁴⁺, Pb^{2+ and Fe3+ etc. The studies included leachability aspects, exchange with other active ions, thermal characteristics, compressive strength of the cement blocks loaded with the resin etc. Studies indicate that the order of the stability of the resin with respect to properties like leachability, exchange properties etc.}

1 illus, 2 tables, 2 ref

001198   Sesha Rao R V S;Deshpande M S M;Shivkumar K (Atomic Minerals Directorate for Exploration and Research, , Central Region Civil Lines, Nagpur - 440 001) : Note on the occurrence of uraniferous phosphatic ferruginous breccia in the lower Vindhyan of Son-Valley around Baskati Sidhi district, Madhya Pradesh. J Geol Soc India 2004, 64(5), 685-8.

Uranium mineralisation associaed with phosphatic ferruginous breccia has been located for the first time within the lower Vindhyan Semri Group of basal sediments in Son Valley around Baskati, Sidhi district, M. P. The phosphatic ferruginous breccia occurs along the reactivated basement fracture that follows the structural grain of Son-Narmada megalineament, and also marks the tectonic contact zone between Vindhyans to the north and crystallines/Mahakoshals to the south. Detailed geological investigations at Baskati reveal uranium enrichment intermittently over a stretch of 2500 m at Baskati block and 400 m in Paniba block further east with an average width of 3 to 5 m. Samples from radiaoactive horizon analysed upto 670 ppm U and 36.87 P₂O₅. Petromineralogical studies reveal that the association of uranium is mostly with the phosphatic phase.

^ssc5 illus, 11 ref

001197   Sathiyanarayanan K;Sabumon P C (Vellore Instiute of Technology, [Deemed University], Vellore-632 014) : An improved methhod for defluoridation. Indian J envir Hlth 2003, 45(1), 65-72.

Fluoride is a naturally occuring toxic mineral present in drinking water and the root cause of many diseases and disorders. Present international drinking water standard set by World Health Organisation (WHO) for fluoride is 1.5 ppm. In order to find the wide spread concentration of fluoride in drinking water of fluoride contaminated aquifer, 30 bore well water samples have been collected from different villages of Natrampalli Union which comes under Tiruvannamalai Circle, Tamil Nadu, India. An attempt to remove fluoride by the use of coagulant, Poly ALuminium Chloride (PAC) was made compared with the most common existing technique Nalgonda Technique" where there was a reversible reaction. The coagulant used in Nalgonda technique is Alum {(Al₂SO₄(₃}. Results show that Poly Aluminium Chloride (PAC) can be an effective coagulant for the removal of fluoride from water with a higher removal efficiency of about 75-85 in less detention time and also observed that the fluoride removal was dependent on initial fluoride concentration and dose of coagulants.

4 illus, 4 tables, 7 ref

001196   Sarkar S;Gupta A (Ph.D. Scholar, Civil Engineering Departmemt, Bengal Engineering College(D.U.), Howrah-711 1003) : Treatment of chrome plating wastewater (cr<. Indian J envir Hlth 2003, 45(1), 73-82.

Suitability of activated alumina for removal of hexavalent chromium from electroplating wastewater has been investigated. Activated alumina exhibited good sorption capacity for hexavalent chromium and pH has no pronounced effect on the sorption capacity. Both batch and column adsorption studies have been carried out and an adsorption column design indicated reasonable depth of column for practical application.

8 illus, 2 tables, 24 ref

001195   Rao R R;Reddy R C;Rama Rao K G;Kelkar P S (National Environmental Engineering Research Institute, , Nehru Marg, Nagpur-440 020) : Assessment of slow filtration system for rural water supply schemes-a case study. Indian J envir Hlth 2003, 45(1), 59-64.

In India, water supply programmes form a part of National Development Plans and are implemented in a phased manner under the Five-Year Plans. A number of departments and ministries of the Central and State Governments have been vested with the responsibility for water supply and sanitation. Due to inherent advantages of slow sand filters over conventional rapid sand filters, the Panchayat Raj Engineering Department (PRED), Government of Andhra Pradesh has designed and constructed a number of slow sand filter plants for rural water supply schemes in the state. At the instance of Netherland Assisted Project (NAP) Office, Hyderabad, NEERI undertook a critical evaluation of the functioning of three slow sand filter plants in Andhra Pradesh and suggested improvements in construction, operation and maintenance (O & M) including a review of design criteria followed by PRED). The outcome of these studies along with suggestions needed to bring about improvements in source protection, design, construction, O&M of slow sand filter and training programme to improve the quality of supervision have been presented.

1 illus, 2 tables, 3 ref

001194   Rao G V;Bhaskara Rao D V (Earth and Atmospheric Sci Dep, Saint Louis Univ, St. Louis Univ, St.Louis, MO63103 (USA)) : A review of some observed mesoscale characteristics of tropical cyclones and some preliminary numerical simulations of their kinematic features. Proc Indian Natn Sci Acad-Pt A 2003, 69(5), 523-41.

A review of some observational mesoscale characteristics of tropical cyclone is presented. Since landfalling tropical cyclones are increasingly studied because of their perceived threat to the public, research employing land-based or airborne radar is emphasized in this review. A Doppler radar study of a mesocyclone associated with a tropical cyclone in Florida that spawned to tornado is presented. Some of the characteristics of the mesocyclone such as reflectivity, depth of the weak echo region, inbound and outbound Doppler winds pertaining to that mesocyclone are given. Relevant satellite imageries in the visible, infrared and microwave wavelengths of two tropical cyclones: Earl 1998 and the Super Cyclone (SC) Orissa 1999 are shown. To explore the dynamics of the above mentioned tropical cyclones on a mesoscale a popular nonhydrostatic model called MM5 was used independently by Saint Louis University (SLU) for Earl and by Andhra University (AU) for Super Cyclone Orissa. Some details of these models are given. The SLU used four domains interacting in two ways, with 81 km, 27 km, 9 km and 3 km grid distances and integrated the model for 24 hours. The AU used two domains, interacting one way, with grid distances of 30 and 10 kilometers and integrated the model for 120 hours. The mesocyclones in TC Earl are characterized by the confluence of streamlines in the low levels. The observed outer rainbands of the SC Orissa are well simulated by the low-level vorticity field. Optimism is expresed in understading the severe weather accompanying landfalling tropical cyclones and predicting their mesoscale characteristics ahead of their land fall using MM5 integration.

18 illus, 30 ref

001193   Rajurkar N S;Nongbri B;Patwardhan A M (Department of Chemistry, University of Pune, , ) : Physico-chemical and biological investigation of river Umshyrpi at Shillong Meghalaya. Indian J envir Hlth 2003, 45(1), 83-92.

River Umshyrpi is the major river in Shillong that passes across the city. Domestic waste, solid waste, agricultural run off from surrounding areas are entering into the river bodies thorugh different drains. Water samples from various sites were collected and analysed for physico-chemical and biological parameters to assess the quality of the river system. The study reveals that physico-chemical parameters are within the permissible limit whereas the biological parameters are found to exceed the permissible limit which indicate unpotability of the water.

17 illus, 2 tables, 5 ref