015520   Ramasamy R;Arul B;Periakali P (Applied Geology Dep, University of Madras, Chennai 600025) : Sulphide mineralisation in crystalline limestones and granitic rocks of Sankaridurgam, Tamil nadu. Indian Miner 2003, 57(3-4), 185-90.

^ssc2 illus, 2 tables, 13 ref

015519   Ram Babu;Dhyani B L;Nirmal Kumar (NO, Central Soil & Water Conservation Research & Training Institute, Dehradun-248 195) : Assessment of erodibility status and refined iso-erodent map of India. Indian J Soil Conserv 2004, 32(3), 171-7.

Erosion Index is one of the important parameter in estimating soil loss from the Universal Soil Loss Equation (USLE) of Wischmeier. For this, monthly, seasonal and annual Erosion Index (El) values of 123 stations were computed for assessing the rainfall erosivity for these stations and preparing the Iso-Erodent Map of India. 75 to 99% of the annual erosion index values in northern, western, central and eastern zones of India are concentrated during southwest (June-September) monsoon while in southern zone these are shared by southwest (June - September) and northeast (October - December) monsoon rains. Iso-erodent values for 500 non-recording stations were computed using relationship developed between mean annual/seasonal (June-September) rainfall and respective erosion index values. Iso-erodent maps of India on annual and seasonal (June - September) basis were developed based on 623 stations' data. Annual El values range from 120 at Bhuj in western zone to 1551 at Honavar in western coast of southern zone in India. The seasonal (June - September) El value varied from 16 at Pamban to 1410 at Honavar. Variation in El reflects the diversity of rainfall erosion potential in different parts of country. Distribution curves expressing average monthly values were prepared and given for selected 20 stations located in different zones. Values of erosion index for return periods of 2,5 and 10 years were also calculated for all the 123 stations. This would help in assessing soil loss with 50,20and 10% probability.

3 illus, 2 tables, 10 ref

015518   Nair K K (Geological Survey of India, , Thiruvananthapuram 695 014) : Geomorphological, geological and structural control of china-clay deposits of Kerala with special reference to Kasaragod district, northern Kerala. Indian Miner 2003, 57(3-4), 155-68.

Kerala is known for good-quality china-clay deposits mined from many places especially from southern and northern parts of the State. In Kasaragod District of North Kerala both residual and sedimentary clay varieties are noticed of which the former is distributed over a large area. Pediplanation, stability of the terrain and climatic conditions promoted large-scale kaolinisation. Shearing and fracturing coupled with intense weathering of the basement rocks such as gneiss, granite and charnockite yielded good china-clay deposits. Fracture pat- terns and horst-and-graben set-up also favoured its accumulation and preservation. A total of thirtyfour prospects covering a cumulative area of 64 sq. km and resource potential of about 600 million tonnes were brought out. Physical properties, chemical composition and mineral assemblages of the clays were determined, and the quality appraisal suggests that the clays are typical china clay comparable in quality to those being mined from different parts of Kerala. In all the cases laterite is the overburden and can also be mined and marketed, it being the main source of construction material in these parts. A comprehensive mining strategy of exploiting both the ore and the overburden would be most suitable for an optimum benefit. Large-scale mining of china clay and the laterite overburden may cause disturbance in the unique landscape pattern of the midland and result in environmental problems, which has to be taken care of while venturing in exploitation of these natural resources.

3 illus, 4 tables, 14 ref

015517   Mohammad N (National Atlas & Thematic Mapping Organisation, , Kolkata 700 064) : Phenoclast segregation and lenticularity of beds of the precambrian conglomerate of jaisamand formation in umra sector, Udaipur district, Rajasthan. Indian Miner 2003, 57(3-4), 177-84.

Precambrian conglomerate beds of the Jaisamand Formation (2.5 Ga) in Umra area were studied to collect quantitative data on phenoclast segregation factor and bed lenticularity index. The quantitative observations made on these bedding characteristics using Clifton methodology suggest that a combination of low lenticularity index and high phenoclast segregation factor characterise a dominant marine wave-worked dynamics that operated during the deposition of Umra conglomerate.

4 illus, 2 tables, 29 ref

015516   Gupta R;Rastogi R A (NO, People's Science Institute, Dehra Dun) : Development and evaluation of geomorphological instanteous unit hydrograph (GIUH) model. Indian J Soil Conserv 2004, 32(3), 188-93.

The hydrological data of Arki watershed of Satluj river catchment collected from the Divisional Forest Office (Hydrology Investigation Division), Shimla, Himachal Pradesh were analysed to develop conceptual hydrologic model. The geomorphologic instantaneous unit hydrograph (GIUH) was developed by GIUH model. The direct runoff hydrographs (DRHs) were developed by convolving effective rainfall values with one hour unit hydrograph (1-hr UH) derived by GIUH model for evaluating prediction performance of the model. The qualitative performance based on visual observations and peak reproduction, etc. and quantitative performance based on certain statistical measures such as coefficient of efficiency, absolute relative error in predicted peak flow rates and relative squared error were evaluated in order to test the validity and assess the applicability of the model. The average values of coefficient of efficiency, absolute relative error in predicted peak flow rates and relative squared error were found to be 0.9515,9.5185 (%) and 0.0244 respectively. Thus the GIUH model can be used for simulating the DRHs for Arki watershed.

6 illus, 2 tables, 18 ref

015515   Ghosh S (Geological Survey of India, , DK-6, Sector-II, Salt Lake, Kolkata 700 091) : Is lonar astrobleme an example of cometary impact?. Indian Miner 2003, 57(3-4), 105-14.

Based on the physico-chemical parameters of the shock-induced throw-out and fall-out ejecta in and around the Lonar astrobleme in Buldana District, Maharashtra, an impact model has been envisaged employing SURFER software package. According to this model, Lonar crater is classified into one that has suffered both high strain rate and high-temperature effects. The peak shock pressure is estimated to be around 1000 kb (100 Gpa). Employing the "Equation of State curves" for basaltic material, the impact velocity is estimated to be around 10 km/sec. Lack of any magnetic anomaly, high-pressure polymorphs and Fe-Ni spherules within the crater suggests that the impacting body was considerably less dense of the order of 1.5 gm/cc, and volatile in nature. Absence of any undisturbed parent bedrock in drill cores at a crater depth of 537m and higher proportion of "Microbreccia" relative to "Coarser breccia" suggests that the Lonar crater was unusual in depth-diameter ratio. Such unusual feature is ascribed to the nature of the bolide which was more in a plasma state rather than a so1id object.

4 illus, 25 ref

015514   Ghose M K;Kundu N K (Centre of Mining Environment, Indian School of Mines, Dhanbad-826 004) : Assessment of soil quality in Raniganj coalfield area. Indian J Soil Conserv 2004, 32(3), 251-3.

^ssc1 table, 3 ref

015513   Gavali N V;Atre A A;Bangal G B (College of Agricultural Engineering, Mahatma Phule Krishi Vidyapeeth, Rahuri-413 722, M.S.) : Relation between geomorphic characteristics of watershed and time to peak and time base of unit hydrograph. Indian J Soil Conserv 2004, 32(3), 184-7.

A study was conducted at Maheshgad watershed, about 2.5 km south of MPKV Central Campus, Rahuri (Dist. Ahmednagar), to develop the relationship between geomorphic characteristics of watershed and time parameters of unit hydrograph. Contour map of Maheshgad watershed and unit hydrographs of eight sub-watersheds in Maheshgad watershed for the year 1997 were collected from Ad-hoc Research Scheme on "Hydrological Studies in Agricultural Watershed". To increase the adaptability and transferability of the developed relationship, the geomorphic characteristics of watershed were grouped in dimensionless parameters which were drainage factor, relative relief, form factor, hypsometric integral, ratio of average length of overland flow and length of watershed and the ratio of time of concentration to the duration of effective rainfall producing unit hydrograph. The multiple linear regression equations were developed for time to peak (t_p) and time base (t_b) of unit hydrograph. The developed equations were tested for adaptability and transferability with the data of two adjacent watersheds in Aagadgaon (Dist. Ahmednagar), which are quite different in morphology but are in similar climatic conditions of Maheshgad watershed. The estimated and observed t_p and t_b for the two watersheds in Aagadgaon are quite close.

5 tables, 6 ref

015512   Das D P;Dutta N K;Dutta D R;Thanavellu C; Baburao K (Geological Survey of India, PGRS Division, CHQ, Calcutta 700 016) : Singhora group - the oldest proterozoic lithopackage of eastern bastar craton and its significance. Indian Miner 2003, 57(3-4), 127-38.

A sedimentary lithopackage exposed towards southeastern 'hook'-shaped part of Chhattisgarh Basin represents the oldest siliciclastics deposited in a small oval-shaped depression of about 1000 sq km. The sequence comprises conglomerate, arkose, feldspathic arenite, argillite and carbonates lying uncomformably over the granitoid-supracrustal basement of Bastar Craton. The lithopackage, designated as Singhora Group, comprises four formations namely Rehatikhol, Saraipali, Bhalukona and Chhuipali Formations, in ascending order. The sequence representing two cycles of sedimentation is unconformably overlain by Chandarpur Group of Chhattisgarh Basin. Singhora Group suffered deformation yielding two sets of warps and broad dome and basin structures in response to intense faulting along N-S, NW-SE, NE-SW and E-W trends with late phase of intrusions, affecting the sequence. Lithostratigraphically, Singhora Group is correlable to the lower part of Pairi Group of Khariar Basin and the sedimentary sequences of Ampani. Distribution of Singhora-equivalent sequences along the eastern margin of Bastar Craton suggests a possible emergence of elongated pericratonic master trough. The probable Early Riphean age of the lithopackage of Singhora has been estimated from stromatolite assemblage and corroborated by absolute age data.

4 illus, 1 table, 15 ref

015511   Chakravarti M;Ray J (Geology Dep, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700 019) : Melting behaviour of Rajmahal basalts of eastern India at one-atmosphere condition. Indian Miner 2003, 57(3-4), 139-44.

One-atmospheric-melting studies of Rajmahal basalts of eastern India throw some new light on the appearance of several liquidus phases. Experimental studies indicate that the crystallisation began at 1190°C with initial nucleation of plagioclase. This was later joined by clinopyroxene (and/or orthopyroxene) and opaque minerals at subsequently lower temperatures. It was found that the entire crystallisation regime corresponding to one-atmospheric condition was rather restricted and ranged from 1190° to 1050°C. The narrow temperature interval indicates rapid cooling of the eruptive magma corresponding to huge effusion of the lava flows onto the Earth's surface.

1 illus, 1 table, 24 ref

015510   Bhattacharya A K;Sengupta K (Geological Survey of India, , DK-6. Sector-II, Salt Lake, Kolkata 700 091) : Study on mineralogical and textural aspects of the lamproites of Kalyani mine East Bokaro coalfield, Jharkhand. Indian Miner 2003, 57(3-4), 169-76.

Kalyani opencast coal mine (23°45'N: 86°E) in the East Bokaro Coalfield, Jharkhand, exposes olivine lamproite, olivine-leucite lamproite and leucite lamproite dyke swarms. Important index minerals'of lamproitic rocks present here are alkali feldspar, titanian tetrafcrriphlogopite, dogtooth xenocryst of olivine, leucite and priderite. Of particular interest is the occurrence of gold in olivine lamproite. The presence of carhonated spinel dunite xcnolith within the rock indicates that the lamproitic magma has possibly been generated by partial melting of spinel dunite rocks. The sequence of crystallisation is olivine-Iamproite, olivine-leucite lamproite and leucite lamproite.

10 illus, 9 tables, 11 ref

015509   Bhatt V K;Goel N K;Mathur B S (NO, Central Soil & Water Conservation Research & Training Institute, Resea, Chandigarh-160 019) : Regional flood frequency analysis using artificial neural network. Indian J Soil Conserv 2004, 32(3), 178-83.

The estimation of flood quantile is needed in various hydrological studies. Usually a stream gauge is unavailable at the site of interest. Therefore regional methods that relate flood magnitude with readily measured catchment and climatic characteristics can provide a practical solution. The results of regression equations that relate the first two L-moments with catchment and climatic characteristics have been compared with results obtained through artificial neural network (Multilayer Perceptron and radial basis function network). Performance evaluation studies indicate that Artificial Neural Network (ANN) models perform better than multiple linear regression analysis (MLRA). Similarly ANN models were found better in prediction of flood magnitude of return period of interest. This is certainly an advantage over traditional methods so called annual flood plus growth curve method. These first two L-moments can be used for parameter estimation for any two-parameter distribution. In the study these were used to estimate the parameters of Gumbel (EV1) distribution.

5 illus, 3 tables, 19 ref

015508   Anil Kumar;Tiwari N;Tripathi S (Soil and Water Conservation Engineering Dep, G. B. Pant Univ of Agriculture and Technology, Pantnagar-263 145) : Development of distribution hydrograph for estimation of direct run off from a hilly watershed in Uttaranchal. Indian J Soil Conserv 2004, 32(3), 206-11.

A distribution hydrograph (DH) is developed for the Gagas sub-watershed of Ramganga river catchment in Uttaranchal. The distribution hydrograph is considered to be more stable than a unit hydrograph (UH) for modeling the rainfall-runoff response of a watershed particularly for computation of its lag time. Its shape may vary from one watershed to another, reflecting the difference in their runoff characteristics. The DH is preferable to UH for comparing the runoff characteristics of watersheds of different sizes. In this study several rainfall-runoff events have been used for synthesis of average DH and prediction of direct runoff hydrograph (DRH) for Gagas watershed. Various relationships have been developed between different hydrological parameters of rainfall-runoff transformation.

6 illus, 3 tables, 6 ref

015507   Aktar K;Roy M K;Ahmed S S (Geology and Mining Dep, University of Rajshahi, Rajshahi 6205, Bangladesh) : Provenance of sandstone of Tista fan, northwestern Bangladesh. Indian Miner 2003, 57(3-4), 115-26.

The Tista fan in Bangladesh is extended for about 181km from Banglabandha (apex) to Hakimpur (toe) in Dinajpur district with a south to southeasterly slope. Petrography of sandstone was carried out from trough cross-stratified sandstone facies (St) with grain size in between coarse to fine sand (Mesh No. 30 and 120) and the facics is exposed in majority of stations on the Tista fan. The sandstones of the Tista fan are composed of quartz (av. 31.3%), feldspar (av. 24.32%), rock fragments (av. 9.62%), mica (av. 13%), heavy minerals (av. 7.37%) and some unidentified minerals (av. 14.39%). The rock fragment includes granule- and pebble- and cobble-sized clasts of gneiss, schist, slate, quartzite, pegmatite, granite, sandstone, siltstone, shale, etc. These sandstones are classified as arkosic wacke. The source of these minerals and rock fragments are the igneous metamorphic, and pre-existing sedimentary rocks. The southerly palcocurrent along with the textural and mineralogical maturity and mineralogical composition indicate that the Himalayas, located to the north of the Tista fan, is the prime source of the sediments. Tectonic provenance of recycled orogene, dissected arc, transitional continent and basement uplift in the Himalayan zone are suggested for the derivation of sediments of the Tista fan.

15 illus, 2 tables, 23 ref

015506   Akhilesh Kumar;Raghuraj Singh;Ram Chandra; Bharali M A (Soil and Water Conservation Engineering Dep, College of Technology, G. B. Pant Univ of Agriculture and Technology, Pantnagar, U.S. Nagar-263 145) : Development of a rainfall simulation system using hypodermic needles. Indian J Soil Conserv 2004, 32(3), 198-205.

A rainfall simulation system of 10 m x 1.4 m size has been developed by using hypodermic needles. The development was based upon the findings of a calibration test performed to obtain an appropriate combination of design variables like needle size, needle to needle spacing, line to line spacing and operating water pressures so as to obtain generated rainfall parameters in the range which commensurates with natural rainfall. It was observed that the developed rainfall simulation system generates continuous rainfall with its intensity in the range of 63.0 mm h^-1 to 170.8 mm h^-1, uniformity coefficient 87.52% to 92.1%, drop size3.05 mm to 4.67 mm and the terminal velocity of raindrops 7.674 m s^-1 to 9.496 m s^-1 for 20 no. size of hypodermic needle at a needle to needle and line to line spacing of 20 cm x 20 cm with operating water pressures in the range of 0.1 kg cm^-2 to 0.6 kg cm^-2. The developed rainfall simulation system is simple and economical in construction, easy in operation and is capable of generating rainfall with its parameters fairly comparable with the natural rainfall.

7 illus, 3 tables, 31 ref

015505   Adhikari R N;Selvi V;Husenappa V (NO, Central Soil and Water Conservation Research and Training Institute,, Bellary-583 101) : Unit hydrograph method for estimating peak rate of runoff of small farm catchments. Indian J Soil Conserv 2004, 32(3), 212-5.

Unit hydrograph is a typical hydrograph for a given basin/catchment. It is called as a unit hydrograph as the runoff volume under the hydrograph is adjusted to 1 cm (or 1 mm) of uniform depth over the entire catchment. An attempt has, therefore, been made to develop a unit hydrograph of three different runoff producing rain storm for three agricultural catchments existing on the research farm with areas ranging from 1 to 2.35 ha. 10 and 25 years runoff frequency was calculated, which thus multiplied with the ordinate of average unit hydrograph to obtain design Hydrograph. Peak of the design hydrograph is the peak rate of runoff. This method is compared with existing method of rational formula and also with 10, 25 year frequency of observed peak rate of runoff. The advantage of unit hydrograph method is that, it will give peak rate of runoff as well as full shape of design hydrograph. The paper also discussed the other application of unit hydrograph like generation of hydrograph from unit hydrograph, as a result of failure of instrument. Limitations and future scope of study is also discussed.

1 illus, 5 tables, 6 ref

014488   Tiwari M M S;Shrivastava P K (Physics Dep, S.G.S. Govt PG College, Sidhi-486 661) : Characteristic features of geomagnetic storms and their long-term relationship with sunspot solar activity cycles. Ultra Scient phys Sci 2004, 16(3), 329-34.

Sunspots a darker and high magnetised region on suns photosphere represent the level of solar activity and play key role in producing major solar and geomagnetic disturbances. Geomagnetic storms are recognised as on abrupt change in the general level of geomagnetic field, which may be as large as several percent of the undisturbed value measured at the surface. Studied long-term variation of geomagnetic cycles for the period of 1985 to 2002. Number of geomagnetic storm vary with solar activity. Sessional variation is also found. The initial phase, main phase and recovery phase of geomagnetic storms are found to vary according to different phases of solar activity cycles.

5 illus, 1 table, 7 ref

014487   Sunil Kumar;Rai A K (Civil Engineering Dep, MIT, Muzaffarpur-842 003) : A study on water crisis management and its governance. Mendel int J 2004, 21(1-2), 25-6.

4 ref

014486   Shrivastava P K;Pande S K (Geology Dep, Govt V.Y.T. P.G. Autonomus College, Durg) : Calculation of ground water balance through ARDC norms: a case study of somni stream watershed, Durg district, Chhattisgarh, India. Ultra Scient phys Sci 2004, 16(3), 385-90.

An attempt has been made to calculate the ground water balance through ARDC (III) norms. The study are Somni Stream Watershed is located in Durg Distruct Chhattisgarh and easily approachable by rail and road both. The study area is having coarse textured drainage network and is mainly underlain by limestone, shales and sandstone of Rajpur Group of Chhattisgarh super group. The ground water structures present in the area are dug wells, dug cumbore wells and bore wells. According to the calculations following ARDC (III) norms the ground water balance in the Somni Stream Watershed is about 1137.52 hactare meter.

2 illus, 3 ref

014485   Joshi J D;Vora J J;Sharma S S;Patel N K; Kothari O K;Salvi K N (Chemistry Dep, Sardar Patel University, Vallabhvidya Nagar-388 127) : Potable water quality with respect to fluoride of Chanasma and Harij taluka of North Gujarat. Ultra Scient phys Sci 2004, 16(3), 355-60.

Groundwater is an important resource of fluoride ion. Variety chemical substance have always contaminated ground water. Fluoride is most dominant ion in the ground water contamination. A study has been undertaken for the determination of fluoride in drinking water taken from Patan taluka and its nearby villages. Fluoride was measured with the help of ion selective electrode method. Most of these villages have more concentration of fluoride as suggested by WHO and ISI. Samples taken from this region have been analyzed and it was found that 75 villages are prone to the excess fluoride concentration in drinking water. The values of fluoride were found from 0.383 mg/l to 9.96 mg/l.

2 tables, 16 ref

014484   Guha S;Francisco J S (Chemistry Dep, Tennessee State Univ, Nashville, TN 37209, U.S.A.) : Bromine-catalyzed oxidation of methane in the earth's atmosphere: An alternate perspective. Res J Chem Envir 2004, 8(3), 11-4.

Methane is an important greenhouse gas existing in the Earth's atmosphere. High concentrations of methane lead to global warming, which poses a concern. Among other processes, the overall build-up of methane is controlled by its oxidation reaction with hydroxyl radicals. A novel scheme is developed for methane oxidation in the atmosphere that clarifies some of the uncertainties involved in the original oxidation scheme proposed by Lary and Toumi. According to the study the oxidation of methane occurs in a bromine-catalyzed cycle that results in the destruction of ozone and the production of carbon monoxide, water and oxygen molecules.

1 illus, 10 ref

013517   Sinha B;Satyavani N;Thakur N K (NO, National Geophysical Research Institute, Hyderabad-500 007) : Analysis of interval velocity vs amplitude blanking in a gas hydrate Province. Curr Sci 2004, 87(11), 165-7.

Seismic reflection profiles across many continental margins have imaged bottom-simulating seismic reflectors (BSRs), which have been interpreted as being formed at the base of a methane hydrate zone. These reflectors might arise from an impedance contrast between high velocity layers, partially hydrated sediments overlying gas/water-saturated sediment study was aimed at amplitude analysis and its relation with velocity on one of the profiles on the western continental margin of India. In our data BSR is found to be discontinuous in the profile and amplitude blanking is seen above the BSR. To get an idea about amplitude in the region with and without BSR, we have performed both amplitude and velocity analysis. The relation between amplitude variation and velocity variation is utilized to estimate range of velocity in the blanked zone.

4 illus, 10 ref

013516   Reddy P R;Chandrakala K (NO, National Geophysical Research Institute, Hyderabad-500 007) : Lateral and vertical crustal velocity and density variations in the Southwestern cuddapah basin and adjoining eastern dharwar craton. Curr Sci 2004, 87(11), 1607-14.

Sersmic, gravity and aeromagnetic data are reviewed to understand the complex nature of thestructure of the Cuddapah basin. Deep Seismic Sounding analogue data acquired along Kavali-Udipi profile, covering middle and western parts of Cuddapah basin and adjoining granitic gneissic terrain of Eastern Dharwar Craton have been primarily used for this study. We have derived a two-dimensional crustal velocity structure by reprocessing of refraction and wide-angle reflection data acquired along the profile. Derived basement and sub-basement crustal structure has brought out finer structural details. Two layers are present above the upper crust. The first layer has a velocity of 5.2 to 5.4 km/s and the basement has a velocity of 5.95 to 6.00 km/s. The upper crust has a velocity of 6.4 km/s, mid crustal velocity is 6.6 to 6.8 km/s, whereas the lower crustal velocity is 7.4 km/s. Moho-1 is observed at an average depth of 37 km with a derived velocity of 7.8 km/s. A deeper Moho-2 is also observed at a depth of 45 km with a Pn velocity of 8.4 km/s. A low-velocity layer (6.5 km/s) separates the two Moho discontinuities. In addition, the analysis has brought out finer crustal velocity-depth details of the region, including presence of regionally extending upper crustal domal features. The study has also revealed the presence of deep-seated faults near Parnapalle, Tonduru and Malepadu. Gravity modelling of the seismic structure further substantiated the results and brought into focus the good correlation of datasets.

4 illus, 30 ref

013515   Gupta V;Bist K S (NO, wadia Institute of Himalayan Geology, 33, General Mahadeo Singh Road, Dehra Dun-248 001) : The 23 September 2003 varunavat parvat landslide in uttarkashi township, Uttaranchal. Curr Sci 2004, 87(11), 1600-5.

Uttarkashi township, located on the right bank of the Bhaghirathi river, is known to nave had a history of natural disasters including the mass movement activities. A. disastrous landslide in the area on the slopes of the Varunavat Parvat struck late in the night on 23 Septem-ber 2003, immediately after the rainy season. The Varuna-vat landslide has been classified as a classical example of debris slide (debris slide in the crown portion and rockfall and rockslide in the middle part). Both natural and human-induced factors are responsible for this slide, however, the main triggering factor is the surface and groundwater. The present study lays the foundations for further work to link landslide activity to rainfall -intensity duration trends so that stochastic relationships may be developed to assess high-risk areas around the slide zone.

7 illus, 7 ref

013514   Govil P;Divakar Naidu P;Radhika T K (NO, National Institute of Oceanography, Dona Paula, Goa-403 004) : Major turbidity flows in the Western indus fan between 290 and 360 kyr. Curr Sci 2004, 87(11), 1597-1600.

Calelum carbonate (CaCO₃), aluminium (Al), titanium (Ti), and terrigenous matter analyses were carried on the Ocean Drilling Programme Site 720A from the Indus Fan in the Arabian Sea. CaCO₃, Al, Ti and terrigenous matter values range from 4.5 to 74.4%, 1.4 to 7.8%, 0.03 to 0.4% and 5.5 to 66.7%, respectively. High CaCO₃ <40-60%) in association With low values of Al, Ti and terrigenous matter from 0 to 290 Kyr(0 to 18 mbsf) and low CaCO₃(<10%) with high values Of Al, rigcnous matter suggest that CaCO₃ fluctuations at this site were controlled by terrigenous dilution. Low Al,Ti and terrigenos matter percentages from 0 to 290 kyr and strikingly high values from 290 to 360 kyr reveal that the supply of terrigenous matter to the Indus Fan was significantly higher during 290 to 360 kyr (18 to 28 mbsf depth) due to massive turbidity flows triggered by slumping.

4 illus, 1 table, 12 ref

013513   Dharma Rao C V;Vijaya Kumar T;Bhaskar Rao Y J (Economic Affairs Dep, Ministry of Finance, Hyderabad-500 001) : The pangidi anorthosite complex, eastern ghats granulite belt, India: mesoproterozoic Sm-Nd isochron age and evidence for significant crustal contamination. Curr Sci 2004, 87(11), 1614-18.

The Pangidi Anorthosite Complex (PAC) is a small, magmatically layered body emplaced into high-grade supracrustal rocks and metamorphosed together with the host rocks in the southern sector of the Eastern Ghats Granulite Belt, South India. It is dominated by coarse-grained anorthosite and leuconorite, minor leuco-gabbronorite and ultramafics with chromitites. The anorthositic rocks contain plagioclase (An_55-70) + ortho-pyroxene (En_50-60) + augite + amphibole + ilmenite + magnetite with accessory olivine, biotite, apatite and rarely coronal garnet related to metamorphic reconstitution. Despite a less calcic plagioclase composition in the an-orthosites, the major and trace element distributions are akin to comparable litho types (at similar SiO₂ wt%) of the Kondapalli layered anorthosite complex in close proximity. However, the PAC shows distinct effects of metamorphism and significant modal volume of secondary hydrous mineral phases unlike the latter. A five-point whole-rock Sm-Nd isochron gives 1739±220 million years (Ma) (2σ) age for the complex, which constraints the younger limit to its intrusion and probably metamorphism under amphibolite to granulite facies conditions. The PAC is characterized by strikingly low ε_{Nd (at 1750 Ma)} of -14.4 ± 3.7, indicating the importance of crustal contamination in its genesis possibly involving significantly older (Late Archaean) crustal components.

4 illus, 2 tables, 20 ref

013512   Dasgupta S;De U K (Atmospheric Science Research Group, Environmental Science Programme, F, Jadavpur University, Kolkata-700 032) : A logistic regression model for prediction of premonsoon convective development over Kolkata. Indian J Radio Space Phys 2004, 33(4), 252-5.

Certain parameters (both dynamic and thermodynamic) have been identified as significant for the occurrence of convective developments in the premonsoon period (March-May) in Kolkata (India). An attempt has been made to develop a logistic regression model for prediction of the risk of occurrence of these convective developments from a knowledge of the values of significant parameters. The model was developed on the basis of a sample of 87 days covering the premonsoon period of the year 1990. When used for the purpose of validation on the basis of data of an arbitrarily chosen year, it yielded about 80% corrct predictions.

1 illus, 2 tables, 5 ref

013511   Basu S (Planetary and Geosciences Div, Nitrogen and Noble Gas Mass Spectrometry Laboratory, Physical Researc, Navrangpura, Ahmedabad-380 009, Email: sudeshna@prl.ernet.in) : Revival of U, Th-<. Curr Sci 2004, 87(11), 1519-22.

U, Th-⁴He is an useful geochronometer that records low temperature geological events that may otherwise go unrecorded in minerals like apatite, zircon and titanite. However, it is important to separate pure, coarse grains for dating to minimize errors on He concentration determination due to pressure of contaminants and ejection effects. Discusses the potential of this dating technique in natural settings and the important factors like-suitable grain selection and appropriate corrections that should be employed to obtain meaningful ages using this technique.

20 ref

012433   Suresh R;Gupta J P;Rajesh Rao P;Bhatnagar A K (India Meteorological Department, , Chennai-600 001) : Time evolution of rain drop spectra over Cuddalore in coastal Tamilnadu. Mausam 2004, 55(3), 441-56.

A disdrometer has been installed at Meteorological Office, Cuddalore in Coastal Tamilnadu during first week of April 2002. An overview of the technicalities and facilities available in this disdrometer besides describing the results of the rain drop-size distribution(DSD) from May to August 2002 covering parts of pre-monsoon (March - May) and southwest monsoon (June - September) season. The rain accumulation as measured by the disdrometer matches perfectly with the surface rain gauge measured amount for the rain rate upto 66 mm/hr. The contrasting features of rain spells over Cuddalore, a coastal station in southern peninsular India are clearly brought out in terms of DSDs albeit the rain amount during these period in the year 2002 was very subdued. The modal rain rate was less than 6 mm/hr (84% frequency) followed by 10-40 mm/hr (11%). The concentration of drops, specifically the concentration of larger drops, per rain spell is higher during June - August than during May. The modal class of drop size has an average diameter of 1.116 and 1.912mm. Both exponential and log-normal distribution seem to be fitting well with the DSD. The rain rate derived from the moment 3.67 (m_3.67) of the moment generating function (MGF) of the lognormal distribution function agrees reasonably well with the disdrometer measured rain rate for both the seasons considered. The variability of rain rate, in one minute interval, clearly reveals how the radar derived rainfall accumulation may go wrong even presuming that one uses a perfect Z - R relationship. This suggests the need for understanding the DSD and the micro-physical processes that cause the variability of concentration of drops more precisely to estimate the rain rate and warns about the need for very frequent low elevation radar scans for estimating the rain accumulation.

8 illus, 8 tables, 25 ref

012432   Sena D R;Kurothe R S (NO, Central Soil & Water Conservation Research & Training Institute, Resea, VASAD-388 306) : Application of rainfall analysis for planning soil and water conservation structures in semi-arid Gujarat. Indian J Soil Conserv 2004, 32(2), 156-60.

Sixteen years (1983-1998) daily rainfall data of Kapadwanj Taluka, District Kheda, Gujarat were analysed for annual, monthly and daily rainfall distribution. Five distribution functions such as Normal, Log Normal, Gumbel, Pearson Type III and Log Pearson Type III were fitted to one, two, three, four and five days' maximum rainfall depths. Gumbel distribution fits better to all consecutive days' rainfall maxima- Similarly the annual series was found to confirm the suitability of Normal distribution. Results of the analyses were, then, used to determine hydrological parameters from daily rainfall records. Rainfall events of required design frequency were estimated for designing suitable water harvesting, drainage and recharge structures in the watershed.

6 illus, 3 tables, 9 ref

012431   Sastry G;Reddy Y V R;Om Prakash (Watershed Management Task Force, Central Research Institute for Dry Land Agriculture (ICAR), Hyderabad, A.P.) : Soil and water conservation interventions in watershed development programmes - economic viability, acceptability and emerging issues. Indian J Soil Conserv 2004, 32(2), 81-90.

A study was undertaken in semi-arid regions of India. Thirty seven watersheds located in agro-ecological regions representing both light and heavy soils, funded by Min. of Agri., MoRD, ICAR, Int'l Agency and NGO were selected. A non treated watershed (control) was also selected adjacent to treated watershed (with treatments) for comparison. Two types of survey were taken up in the study. They include: i) Rapid reconnaissance survey and ii) Detailed field survey. Data on bio-physical and socio-economic aspects were collected. Economic viability in terms of employment generation, additional benefit-cost ratio and additional annuity value have been presented. Acceptability in terms of participation at various stages of project implementation were assessed. The analysis shows that while people participated during project planning and execution stage, the same was low during monitoring and evaluation and post project maintenance.

11 tables, 9 ref

012430   Sarkar J;Gadgil A S (India Meteorological Department, , Pune-411 005) : Evaluating bioclimate aspects over the Vidarbha region. Mausam 2004, 55(3), 485-94.

Some of the important bioclimatic aspects, outgoing water budget from the human body in terms of respiratory and non-respiratory evaporative losses, human discomfort and wind chill have been studied. Outgoing water budget has been computed using monthly normals of the maximum temperature and vapour pressure for a number of fairly well distributed stations in the Vidarbha region. Discomfort has been quantified using Thom's Temperature-Humidity Index (THI) or Discomfort Index and wind chill aspects have been studied using the 'wind chill index (WCI)' of Siple and Passel (1945). The study reveals that total water loss from the human body, sum of respiratory and non-respiratory losses, is maximum (384 g. day^-1) in summer and minimum (116 g. day^-1) in monsoon. However, highest respiratory loss of 213 g.day^-1 is observed in winter and that of lowest (66 g. day^-1) in monsoon. Sensible sweating is very much felt in summer. However, it is not at all felt in winter and post monsoon. Though mornings are comfortable in March, yet the entire region starts experiencing discomfort in the evening hours. As expected, in April and May maximum discomfort prevails. Buldhana district, in the western part of the study region, remains comfortable both during winter and summer in the morning hours. Average cooling power over Vidarbha in winter is observed to be 342 W/m². At Nagpur, maximum cooling power (389 W/m²) has been noticed in this season. Isopleth analysis of monthly mean hourly wind chill reveals that in peak winter (December and January) only during 1300-1700 hours Nagpur climate is 'pleasant' and rest of the day is 'cool' to 'very cool'. However, in peak summer (May) only during 0400-0600 hours climate is 'pleasant' and remaining part of the day is 'warm' to 'hot'. Even in April, despite its being a prominent summer month, climate remains 'cool' from 0300 to 0700 hours.

1 illus, 6 tables, 23 ref

012429   Sadeghi S H R;Singh J K;Mahdavi M (Watershed Management Engineering Dep, College of Natural Resources and Marine Sciences, Tarbiat Modarres Uni, Noor-46417, Iran) : Feasibility evaluation of computer model Sedimot II in flood estimation for Amameh watershed in Iran. Indian J Soil Conserv 2004, 32(2), 95-9.

The recent version of the Sedimentology by Distributed Model Treatment approach, named as SEDIMOT II has been applied to assess its applicability on Amameh watershed of Iran. The Amameh watershed, having an area of 3712 ha, was divided into 12 sub-watersheds. The input variables required for the model, such as, the curve number, time of concentration, Muskingum's model parameters, characteristics of storms and other essential information were obtained for each sub-watershed by field survey and lab experiments. In the present study 12 storms, having coincident hyetographs and hydrographs were selected to calibrate and validate the model for the watershed. A high degree of agreement, above 92 per cent was found between the computed and the observed outputs. The equality of the averages of these two sets of data was also confirmed by the t-student test. The results of model application purported that the efficiency and accuracy of the model is high although it was very sensitive to the variation of CN and time of concentration.

4 illus, 5 tables, 16 ref

012428   Ram L C;Kuar S (Meteorological Centre, , Lucknow) : Quantitative precipitation forecasts for upper yamuna catchment by synoptic analogue method. Mausam 2004, 55(3), 508-11.

sc, 1 illus, 3 tables, 3 ref

012427   Rajendra Kumar J;Thapliyal V;Dash S K (India Meteorological Department, , New Delhi-110 003) : Decadal and epochal variation of frequency and duration of monsoon disturbances and their secular relationship with rainfall over India. Mausam 2004, 55(3), 397-408.

Decadal and epochal variation of frequency and duration of monsoon disturbances like low pressure areas (lows), depressions and Cyclonic Storms (CS) over Indian region are studied by using 110 years (1890-1999) data. No linearly decreasing/increasing trend is observed during 110 years period in any of their frequencies. However, epochal linearly decreasing/increasing trends are noticed in decadal frequencies or duration of different monsoon disturbances. Decadal frequencies of depressions, CS and depressions are decreasing from 1970-79, till recently ended decade of 1990-99. During recent decade, less than half of the total number of depressions and CS are formed compared with 1970-79. On the other hand, total number of lows are increasing significantly from 1960-69 to recent decade, when more than double the number of lows of 1960-69 are formed. Since Indian Summer Monsoon Rainfall (ISMR) also shows interdecadal variation of below normal and above normal phases, variation of frequencies of different monsoon disturbances and their total durations are also examined in similar time scale to understand their relationship with interdecadal variation of ISMR. Stability and secular nature of these relationships are also examined based on their decadal and 10-year moving Correlation Coefficients (CC) for the period 1890-1999. Relationship of decadal anomaly of their frequencies with interdecadal variation of ISMR shows that number of depressions and CS, are higher than the normal during the above normal ISMR decades and less during the below normal decades of ISMR. Reverse is true for the number of lows. The decadal and 10-years moving CC between ISMR and frequencies of different monsoon disturbances and total monsoon disturbance days clearly show epochal variation of their relationship in interdecadal time scale with ISMR. The study shows that secular variation of CC not only exists between ISMR and its various regional and global parameters used in long range forecast of ISMR but also between ISMR and its main synoptic features e.g., monsoon disturbances.

11 illus, 13 ref

012426   Pyasi S K;Singh J K (NO, Jawaharlal Nehru Krishi Vishwa Vidyalaya-Zonal Agricultural Research S, Tikamgarh-472 001, Madhya Pradesh) : Sediment prediction by modelling runoff-sediment process. Indian J Soil Conserv 2004, 32(2), 100-07.

Runoff - sediment process of the Naula watershed of Ramganga river catchment in Uttaranchal, India was modeled by applying dynamic approach. It was found that linear system technique can be extended to model the runoff- sediment process in terms of log-transformed daily data sequence and only non-linear sediment yield dynamic models are suitable for the study area. The models based on the concept of assigning the different weightages to antecedents events were found to be suitable for study area. The fluvial system of the Naula watershed exhibits a strong memory on daily basis.

1 illus, 3 tables, 5 ref

012425   Prakasa Rao G S;Jaswal A K;Kumar M S (India Meteorological Department, , Pune-411 005) : Effects of urbanization on meteorological parameters. Mausam 2004, 55(3), 429-40.

In developing countries like India, the urban environment is constantly under stress as a result of migrant population, enhanced energy consumption of the growing population, increased traffic load and industrial activity, deforestation and release of waste products into the atmosphere and hydrosphere. This urbanization coupled with industrialisation affect the urban climate like temperature, precipitation, wind, relative humidity and bright hours of sunshine. Most of the studies are mainly confined to the mid-latitude cities and very little is known about these urban induced changes (except for temperatures) for low latitude cities. There has been a conspicuous increase in the number of industries after 1950 in the cities. Fifteen cities (including four metros) with a population of more than 1 million are selected for this study. Linear trend analysis was carried out over the climatologically data for different meteorological parameters viz., incoming solar radiation, bright hours of trends observed in these meteorological parameters are discussed.

9 illus, 2 tables, 6 ref

012424   Potdar S S;Srivastava R;Nagaraju M S S;Prasad J;Saxena R K (National Bureau of Soil Survey and Land Use Planning, , Amaravati Road, Nagpur-440 033) : Mapping of erosional soil loss in Nanda-Khairi watershed of Nagpur district of Maharashtra using remotely sensed data and GIS techniques. Agropedology 2003, 13(2), 10-8.

A study was taken up to map the erosional soil loss in Nanda-Khairi watershed of Nagpur district of Maharashtra using geocoded false colour composites (FCC) of IRS-1C (LISS-III) data of kharif and rabi seasons. The data related to soil, slope length and steepness, crop management and conservation measures were derived from satellite data, toposheet and ground truth survey and used as inputs in USLE Model for assessment of erosional soil loss. The soil erosion map prepared by the integration of USLE factors revealed five soil erosion classes. Nearly 62 per cent area of the watershed was under slight erosion with soil loss of <5 t/ha/yr. The moderately slight erosion (5-10 t/ha/yr) and moderate erosion (10-15 t/ha/yr) covered 28.1 and 0.4 per cent area of the watershed, respectively. The area under moderately severe (15-20 t/ha/yr) and very severely erosion (>40 t/ha/yr) classes covered 6.5 and 1.0 per cent area, respectively. Based on erosion class appropriate conservation measures have been suggested.

1 illus, 5 tables, 12 ref

012423   Louis I F;Karantonis G A;Voulgaris N;Louis F (Geophys & Geothermic Dep, Univ of Athens Panepistimiopolis, Ilissia, Athens 15784, Greece) : The contribution of geophysical methods in the determination of aquifer parameters: the case of mornos river delta, Greece. Res J Chem Envir 2004, 8(4), 41-9.

Knowledge of hydraulic conductivity and transmissivity is essential for the determination of natural water flow through an aquifer. although these characteristics are mainly deduced from pumping test analysis, attempts have been made to employ geophysical methods in order to reduce the amount of hydrogeological observations and the resulting cost. Use of layer thickness, as derived from the interpretation of resistivity soundings data and hydraulic conductivity calculated on the basis of both hydrogeological and geophysical data led to the calculation of aquifer transmissivity. this technique was used for the determination of aquifer parameters in Mornos River Valley at central Greece. Maps of the basement relief, resistivity, transmissivity and Transverse Resistance provided the means to identify areas where the aquiferous zone is prolific. The good agreement between aquifer hydraulic conductivityes obtained from the resistivity soundings interpretation and those deduced from pumping test analysis emphasizes the potential of the methodology.

12 illus, 13 ref

012422   Latha G;Ramadass G A;Rajendran V (NO, National Institute of Ocean Technology, Chennai-601 302) : Mean sea level extraction and analysis from tidal measurements. Mausam 2004, 55(3), 511-4.

4 illus, 6 ref

012421   Kukal S S;Bawa S S (Soils Dep, Punjab Agricultural University, Ludiana-141 004) : Performance of gully control measures in foothills of lower Shiwaliks. Indian J Soil Conserv 2004, 32(2), 161-3.

1 table, 9 ref

012420   Khole M;De U S (Meteorological office, , Pune-411 005) : Association between the monsoon onset over Kerala (mok) and sea surface temperature (sst) over North Indian ocean. Mausam 2004, 55(3), 495-6.

4 illus, 3 ref

012419   Kane R P (Instituto National de Pesquisas Espaciais, , C.P. 515, 12245-970, Sao Jose dos Campos, SP, Brazil) : Solar UV, stratospheric ozone and UVB. Mausam 2004, 55(3), 457-68.

The variations of stratospheric ozone and UVB observed at ground were compared with those of solar indices. During sequences of 27-day oscillations, X-ray had very large amplitudes (exceeding 50%), EUV near 30 nm had ″20%, Lyman alpha 121.6 nm ″10%, Mg II 280 nm ″5%, and continua 180-210 nm ″2%, 210-240 nm ″1.5%, 240-300 nm ″1 %, 300-350 nm ″0.5%. There were distinct peaks seen in all of these, with spacing of roughly about 27 days. For effects on stratospheric ozone, the relevant wavelengths are mostly in the continua. In the 27-day sequences, the Dobson ozone at Arosa (47° N, 10° E) showed large fluctuations (″50%) with many peaks, but the peaks did not match with the peaks of solar indices. During one such 27-day sequence, the TOMS ozone overpass over Kagoshima, Japan (32° N, 121° E) and the UVB (295-325 nm) observed at Kagoshima showed large day-to-day fluctuations, ″20% for ozone, ″50% or UVB, but the peaks of ozone and UVB did not match with each other, nor with the peaks of solar indices, thus indicating altogether different mechanisms as their causes. In long-term changes for Arosa Dobson ozone, the largest fluctuations were the seasonal variation (″40% range, peak to trough) and the next largest were the QBO (Quasi-biennial oscillation, ″7%, peak to trough). Solar cycle variation ranges of ozone (peak to trough) were only ″2.6% in cycle 19 (sunspot maximum number 210), ″3.5% in cycle 20 (sunspot maximum number 111) and uncertain thereafter, because of the global depletion which started in 1980. For 1991-1997, the monthly values of ozone at Thessaloniki, Greece (40° N, 23° E) were anti-correlated with 305 nm UVB (1% ozone decrease corresponded to ″2% UVB increase), but poorly correlated with 325 nm UVB, indicating that ozone-UVB relationship was highly wavelength-dependent. However, whereas solar indices had a maximum in 1991 and a minimum in 1996, neither ozone nor any of the two UVB 305 nm and 325 nm showed resemblance with the solar index variations. In particular, ozone level was high in 1991 but decreased considerably within two years (by 1993). A comparison with ozone at Arosa (47° N) and Syowa (69° S) showed that this drop is not related to solar cycle but is due to the global depletion of ozone.

7 illus, 39 ref

012418   Jayaanthi N;Mazumdar A B;Sunitha Devi S (Meteorological Office, , Pune-411 005) : Cyclones and depressions over north Indian Ocean during 2003*. Mausam 2004, 55(3), 389-96.

1 illus, 3 tables

012417   Guhathakurta P;Srivastava A K (India Meteorological Department, , Pune-411 005) : Evidence of climate jump in annual temperature in India. Mausam 2004, 55(3), 419-28.

Annual mean temperature of 50 well-distributed stations in India is analyzed for trend and climate jump. Four statistical tests are used to detect the climate jump. Table-look-up test, which is more appropriate than 't' test for time series data, has been applied for the first time to detect the climate jump. Sudden changes in climate are noticed by getting discontinuities or jump in annual mean temperature of most of the stations. It was found that while the northern India received climate jump much earlier i.e. during the decade 1931-1940, extreme south Peninsular India received climate jump between 1961-63.

4 illus, 1 table, 16 ref

012416   Chaudhuri S;Chattopadhya S (Atmospheric Sciences Dep, Calcutta Univ, Kolkata-700 009) : Variation in annual rainfall of Vidarbha during the last century (1901-2000). Mausam 2004, 55(3), 497-507.

sc, 4 illus, 3 tables, 4 ref

012415   Basu G C;Bhattacharjee U;Ghosh R (Regional Meteorological Centre, , Kolkata-700 027) : Statistical analysis of rainfall distribution and trend of rainfall anomalies districtwise during monsoon period over West Bengal. Mausam 2004, 55(3), 409-18.

The statistical analysis of rainfall distributions in different districts of West Bengal during monsoon period for 68 years (1931 -98) have been studied. The statistical parameters such as moments, coefficient of skewness and kurtosis have been computed to understand the nature of such rainfall distribution in each district. The rainfall anomalies during monsoon period (June-September) have also been studied for each district of two meteorological Sub-divisions, Sub-Himalayan West Bengal (SHWB) and Gangetic West Bengal (GWB) by fitting regression lines through 'Least Square Method' and results for rainfall trends for each district of West Bengal have been discussed.

2 illus, 5 tables, 9 ref

012414   Agnihotri Y;Samra J S;Aggarwal R K;Mittal S P;Bansal R C;Yadav R P;Prasad R (NO, Central Soil and Water Conservation Research and Training Institute, R, Chandigarh-160 019) : Impact analysis of a watershed management project in Shivalik foothills through multiple discriminant function approach. Indian J Soil Conserv 2004, 32(2), 91-4.

A large number of watershed management projects taken up along the Shivalik foothills during the recent years have water harvesting as an important component leading to more income from agriculture and milk production. The fuel and fodder availability from the farmers' fields also increases with such projects which is expected to affect the collection of these commodities from the forest area. The paper attempts to perform impact analysis of one such watershed management project at Relmajra, District Nawan Shahar, using 'Multiple Discriminant Function'. The study is based on 'with and without (control)' and 'before and after the project' approach. Inter comparison between the watershed village (Relmajra) and control village (Taunsa) indicated 'the income from agriculture' as the main discriminating variable. 'Income from milk' did not play a significant role in discriminating the (post project with and without situation) populations. 'Collection of fuel' (q yr^-1) 'Collection of fodder' (q yr^-1) contributed significantly in discriminating the populations under the aforesaid situation.

2 tables, 4 ref

011437   Suresh R;Gupta J P;Rajesh Rao P;Bhatnagar A K (India Meteorological Department, , Chennai-600 001) : Time evolution of rain drop spectra over Cuddalore in coastal Tamilnadu. Mausam 2004, 55(3), 441-56.

A disdrometer has been installed at Meteorological Office, Cuddalore in Coastal Tamilnadu during first week of April 2002. An overview of the technicalities and facilities available in this disdrometer besides describing the results of the rain drop-size distribution(DSD) from May to August 2002 covering parts of pre-monsoon (March - May) and southwest monsoon (June - September) season. The rain accumulation as measured by the disdrometer matches perfectly with the surface rain gauge measured amount for the rain rate upto 66 mm/hr. The contrasting features of rain spells over Cuddalore, a coastal station in southern peninsular India are clearly brought out in terms of DSDs albeit the rain amount during these period in the year 2002 was very subdued. The modal rain rate was less than 6 mm/hr (84% frequency) followed by 10-40 mm/hr (11%). The concentration of drops, specifically the concentration of larger drops, per rain spell is higher during June - August than during May. The modal class of drop size has an average diameter of 1.116 and 1.912mm. Both exponential and log-normal distribution seem to be fitting well with the DSD. The rain rate derived from the moment 3.67 (m_3.67) of the moment generating function (MGF) of the lognormal distribution function agrees reasonably well with the disdrometer measured rain rate for both the seasons considered. The variability of rain rate, in one minute interval, clearly reveals how the radar derived rainfall accumulation may go wrong even presuming that one uses a perfect Z - R relationship. This suggests the need for understanding the DSD and the micro-physical processes that cause the variability of concentration of drops more precisely to estimate the rain rate and warns about the need for very frequent low elevation radar scans for estimating the rain accumulation.

8 illus, 8 tables, 25 ref

011436   Sena D R;Kurothe R S (NO, Central Soil & Water Conservation Research & Training Institute, Resea, VASAD-388 306) : Application of rainfall analysis for planning soil and water conservation structures in semi-arid Gujarat. Indian J Soil Conserv 2004, 32(2), 156-60.

Sixteen years (1983-1998) daily rainfall data of Kapadwanj Taluka, District Kheda, Gujarat were analysed for annual, monthly and daily rainfall distribution. Five distribution functions such as Normal, Log Normal, Gumbel, Pearson Type III and Log Pearson Type III were fitted to one, two, three, four and five days' maximum rainfall depths. Gumbel distribution fits better to all consecutive days' rainfall maxima- Similarly the annual series was found to confirm the suitability of Normal distribution. Results of the analyses were, then, used to determine hydrological parameters from daily rainfall records. Rainfall events of required design frequency were estimated for designing suitable water harvesting, drainage and recharge structures in the watershed.

6 illus, 3 tables, 9 ref