009548   Meshram D T;Gorantiwar S D;Mittal H K;Singh N V (NO, , NRC on Pomegranate, Shelgi, Solapur, Maharashtra, Email: gomesh1970@rediffmail.com) : Computation of reference crop evapotranspiration of Nasik station of Maharashtra, India. Mausam 2013, 64(2), 357-62.

Study was conducted to know the best method for estimation of reference crop evapotranspiration (ET_r) for Nasik station (Latitude 20° 53' N, Longitude 75° 16' E and altitude 565.0 m amsl), Maharashtra, India. Reference crop evapotranspiration is a basic parameter in irrigation system design. Six reference crop evapotranspiration methods were used for their daily performances under semi-arid climatic condition. The Penman-Monteith method standardized by FAO was used to compare with the Modified Penman, Hargreaves-Samani, Pan Evaporation, Blanney-Criddle and Radiation methods. Performances of these methods were made on the basis of the least root mean square error (RMSE) and regression analysis (RA). The value of RMSE ranges from 2.01 to 1.09 with the highest in Pan Evaporation method followed by Blanney-Criddle, Radiation method, modified Penman and Hargreaves-Samani method. Out of six methods Hargreaves-Samani was found to have least root mean square error (RMSE = 1.09 mm/day) and highest correlation coefficient (r=0.99) under semi-arid climatic conditions of Nasik station of Maharashtra.

14 illus, 15 ref

009547   Mathur A K;Gangwar R K;Gohil B S;Deb S K; Prashant Kumar;Shukla M V;Simon B;Pal P K (Atmosphere and Oceanic Sciences Group (EPSA), Space Applications Centre (ISRO), Ahmedabad-380 015, Email: bsgohil@sac.isro.gov.in) : Humidity profile retrieval for SAPHIR on-board the Megha-Tropiques. Curr Sci 2013, 104(12), 1650-5.

Megha-Tropiques (MT) satellite, a joint Indo-French mission, was launched by ISRO's PSLV-C18 on 12 October 2011 from Sriharikota, India. SAPHIR, a microwave humidity sounder on-board Megha Tropiques operates in six channels with frequencies around 183.31 GHz. A radiative transfer simulation-based operational algorithm has been developed to retrieve layer-averaged relative-humidity (LARH) for six atmospheric layers from the surface to nearly 12 km using SAPHIR observations over land and ocean under non-rainy conditions. SAPHIR-derived LARH for the period July to November 2012 has been validated with concurrent quality-controlled radiosonde observations as well as with ECMWF analysis data. Global validation with radiosonde and ECMWF data shows that root mean square deviation in LARH for all the six layers is nearly 20% and 15% respectively, after bias correction.

4 illus, 4 tables, 9 ref

009546   Maiti S (Geology Dep, Presidency Univ, 86/1 College Street, Kolkata-700 073, Email: s.maiti@yahoo.co.uk) : Interpretation of coastal morphodynamics of Subarnarekha estuary using integrated cartographic and field techniques. Curr Sci 2013, 104(12), 1709-14.

Cartographic techniques are frequently applied for coastal mapping, but their application for the study of coastal morphodynamics is unpopular, as they only give limited parameters like plan-view, geometry, area-length measurement and lithology. On the other hand, detailed study of morphodynamics requires extra information like depthwise variation in lithology and absolute dating. Since both these techniques are expensive, cartographic techniques can be cost-effective supplementary. In the present study, morphodynamic history of Subarnarekha estuary from 7000 years BP has been interpreted applying data from cartographic techniques along with shallow wells, ^{14C-dating and literature survey. Geomorphologic features of the coastal plain were identified in the order of hierarchy, viz. chenier plain (first order); beach ridge complex, spit complex, chenier complexes (second order); cheniers (third order); and simplest ridge, spit, washover beach (fourth order). Following this field-investigated geological history of river dynamics (both Ganges and Subarnarekha) and sea-level changes identified by earlier researchers were merged with cartographi-cally observed features. The studied ridge chronology provides six sequences of chenier complex development agewise, whereas geometry of spit complexes suggests chronological conversion of Subarnarekha estuary from initial wave-dominated to tide-dominated flow.}

4 illus, 2 tables, 9 ref

009545   Laskar S I;Roy Bhowmik S K;Sinha V (NO, , India Meteorological Dep, New Delhi-110 003, Email: drsebul@gmail.com) : Some statistical characteristics of occurrence of fog over Patna airport. Mausam 2013, 64(2), 345-50.

In this paper some statistical characteristics of fog, such as frequencies of occurrence, time of onset, duration, intensity and time of dispersal over Patna airport are studied making use of 10 years data for the period November-February, 2000-2010. The result shows that during the last ten years frequency of fog over Patna airport has increased significantly in all the four months as compared to the climatology based on available synoptic and current weather observations during 1961-90 and 1951-80. The most favourable month for occurrence of fog over Patna airport has been identified as December followed by January. Percentage frequency is highest for duration of fog for more than 5 hours in the months of December and January whereas in the months of November and February frequency is highest for duration less than 2 hours. The formation of fog mostly observed during 0000-0200 UTC and dissipation during 0200-0500 UTC. Percentage frequency of very thick fog was found to be highest in the month of November. In the months of December and January in most of the cases Fog Stability Index (FSI) based on 1200 UTC radiosonde data leading to occurrence of fog during following night/morning has been found to be less than 40.

1 illus, 5 tables, 12 ref

009544   Kotal S D;Roy Bhowmik S K (India Meteorological Dep, NWP Division, New Delhi-110 003, Email: sdkotal.imd@gmail.com) : Large-scale characteristics of rapidly intensifying tropical cyclones over the Bay of Bengal and a rapid intensification (RI) index. Mausam 2013, 64(1), 13-24.

Rapid intensification index (RII) is developed for tropical cyclones over the Bay of Bengal. The RII uses large-scale characteristics of tropical cyclones to estimate the probability of rapid intensification (RI) over the subsequent 24 hrs. The RI is defined as an increase of intensity 30 kt (15.4 ms^{-1) during 24 hrs, which represents approximately the 93rd percentile of 24 hrs intensity changes of tropical cyclones that developed over the Bay of Bengal during 1981-2010. It is found that 32% of all very severe cyclonic storms (VSCS) and all super cyclonic storms (SUCS) underwent RI phase at least once during their lifetime. Various large-scale variables associated with the RI cases are compared to those of non-RI cases. These comparisons show that the RI cases generally occur at higher latitude and are intensifying at a faster rate during the previous 12 hrs than the non-RI cases. The statistical analysis also shows that the RI cases are embedded in regions where the upper-level divergence, lower-level relative vorticity and relative humidity are more and vertical winds shear is less than certain threshold values of the respective variables. Finally, the initial wind speed of RI cases is higher and tends to move with a faster translational speed than the non-RI cases. The RII technique is developed by combining threshold (index) values of the eight variables for which statistically significant differences are found between the RI and non-RI cases. The probability of RI is found to be increases from 0% to 100% when the total number of indices satisfied increases from zero to eight.}

9 illus, 3 tables, 39 ref

009543   Kotal S D;Bhattacharya S K (NO, , India Meteorological Dep, Email: sdkotal.imd@gmail.com) : Tropical cyclone genesis potential parameter (GPP) and it's application over the North Indian Sea. Mausam 2013, 64(1), 149-70.

Analysis of tropical cyclone genesis potential parameter (GPP) for the North Indian Sea is carried out. The genesis potential parameter developed by Kotal et al. (2009) is computed based on the product of four variables, namely: vorticity at 850 hPa, middle tropospheric relative humidity, middle tropospheric instability and the inverse of vertical wind shear at all grid points over the area. The GPP at a grid point is considered under the conditions that all the variables vorticity, middle tropospheric relative humidity, middle tropospheric instability and the vertical wind shear are greater than zero and it is taken as zero when any one of these variables is less or equal to zero. The variables are computed using the European Centre for Medium Range Weather Forecast (ECMWF) model data. Forecast of the genesis parameter up to seven days is also generated on real time using the ECMWF model output (available at http://www.imd.gov.in/section/nhac/dynamic/Analysis.htm). Higher value of the GPP over a region indicates higher potential of genesis over the region. Region with GPP value equal or greater than 30 is found to Be high potential zone for cyclogenesis. The analysis of the parameter and its effectiveness during cyclonic disturbances in 2010 affirm its usefulness as a predictive signal (4-5 days in advance) for cyclogenesis over the North Indian, Sea and for determining potential for intensification of developing and non-developing systems at the early stages of development.

95 illus, 11 ref

009542   Kokila R;Iyengar R N (Centre for Disaster Mitigation, Jain Univ, Bangalore-562 112, Email: nimai.ramesh@gmail.com) : Prediction of the Indian summer monsoon rainfall for 2013 based on past rainfall data. Curr Sci 2013, 104(12), 1596-7.

2 illus, 2 tables, 4 ref

009541   Khaled S M E;Ghobrial R A R (Mathematics and Theoretical Physics Dep, Nuclear Research Centre, Atomic Energy Authority, Cairo, Egypt, Email: essa_ksm@yahoo.com) : Diffusion from a point source using power law of wind speed. Mausam 2013, 64(2), 351-6.

In the present paper, a model for the diffusion of material from a point source in an urban atmosphere is incorporated. The plume is assumed to have a well-defined edge at which the concentration falls to zero. The vertical wind shear is estimated using power law, by employing most of the available techniques of stability categories. The concentrations estimated from the model were compared favorably with the field observations of investigators.

3 illus, 5 tables, 8 ref

009540   Joshi P K;Joshi A (NO, TERI Univ, 10 Institutional Area, Vasant Kunj, New Delhi-110 070, Email: pkjoshi27@hotmail.com) : Adding audio to digital earth - enhancing geospatial portals. Curr Sci 2013, 104(11), 1463-5.

^ssc8 ref

009539   Joshi P;Ganju A (Snow and Avalanche Study Establishment, Research and Development Centre Him Parisar, Sector 37-A Chandigarh-160 036, Email: piyush.joshi@sase.drdo.in) : Downscaling of MM5 model output using artificial neural network over western Himalaya. Mausam 2013, 64(2), 221-30.

Western Himalaya receives enormous amount of precipitation in the form of snow due to eastward moving synoptic weather system called western disturbance (WD). MM5 a numerical weather prediction (NWP) model, provides precipitation forecast over a grid. Statistical downscaling of NWP output can improve forecast accuracy. In this study artificial neural network (ANN), a non linear method is used to downscale MM5 model forecast to location specific precipitation forecast over western Himalaya. Data of winter months (November to March) from 2003 to 2008 are considered for the study. Data from 2003 to 2007 is used for training and data of winter 2007-2008 is used for validation purpose. In the training process the input-output relationship is extracted and final weight matrix are computed.

5 illus, 5 tables, 14 ref

009538   Jha T N;Mohapatra M;Bandyopadhyay B K (NO, , India Meteorological Dep, New Delhi-110 003, Email: tilanand@yahoo.in) : Estimation of intensity of tropical cyclone over Bay of Bengal using microwave imagery. Mausam 2013, 64(1), 105-16.

Microwave cloud imageries and derived products in the frequency of 85 GHz have been examined for five cyclones that occurred during FDP period (15 October- 30 November) of 2008-2010 over the Bay of Bengal to estimate the brightness temperature, brightness temperature anomaly, location of centre, maximum sustained wind (MSW) at surface level and estimated central pressure (ECP) associated with cyclones in their different stages of intensification like depression (D), deep depression (DD), cyclonic storm (CS), severe cyclonic storm (SCS), very severe cyclonic storm (VSCS), etc. Also the observed brightness temperature anomalies are compared with theoretically derived brightness temperature anomalies based on the best track estimates of ECP and outermost pressure for these cyclones. The location of centre, ECP and MSW based on microwave imagery estimates have been compared with those available from the best track and Dvorak's estimates of India Meteorological Department and analyzed. The difference in location of the centre of cyclonic disturbance (CD) as estimated by microwave imageries and best track estimates decreases with intensification of the disturbances and varies from about 25 km in depression (D) stage to 18 km in VSCS stage whereas the difference is significantly higher in case of Dvorak estimate compared to best track estimate. The MSW based on microwave estimates is higher than that of best track estimates by about 28 knots during VSCS and 6-8 knots during D, CS, SCS stage. Considering relative difference with respect to best track estimates, the MSW is overestimated in microwave by about 12-15% in case of CS and SCS stage and by about 30% in VSCS stage while Dvorak's MSW overestimation reduced to 15-18% during CS, SCS and VSCS stages. Brightness temperature of the order of 230 K is favourable for genesis (formation of D), 250K for its intensification into CS, 260 K for intensification into SCS and 270K for its further intensification into VSCS stage over the Bay of Bengal. Detection of threshold value of brightness temperature may provide adequate lead time to forecast intensification of the system. Similarly, when brightness temperature anomaly exceeds 3K, CS intensify into SCS and 8K, it intensifies into a VSCS over Bay of Bengal.

8 illus, 3 tables

009537   Jaiswal P;Srinivasan P;Venkatraman N V (Geological Survey of India, Geohazards Research and Management Cell, 15 A & B, Kyd Street, Kolkata-700 016, Email: pankaj.jaiswal2@gmail.com ) : Data-guided heuristic approach for landslide susceptibility mapping along a transportation corridor in the Nilgiri hills, Nilgiri district, Tamil Nadu. Indian J Geosci 2013, 67(3-4), 273-88.

Landsliding is causing persistent problem along transportation corridors in the Nilgiri Hills, Tamil Nadu. It severely damages properties (alignments, buildings, vehicles, etc.) and lives, and also affects the society by disrupting the utility services and economic activities. In this paper, a data-guided heuristic GIS-based approach of landslide susceptibility mapping is presented for a rail-road corridor, between Mettuppalayam and Ooty via Coonoor, in the Nilgiri District, Tamil Nadu. The method applied in this work on 1:25,000 scale is essentially adapted after the Bureau of Indian Standard (BIS) Guidelines on 'Macro-scale Landslide Hazard Zonation'. Modifications were made in the type of factor class and the specified LHEF rating, given in BIS Guidelines for optimal evaluation of landslide susceptibility in the Nilgiri Hills. LHEF ratings were modified based on the percentage occurrence of landslides in different causative factors. The landslide susceptibility modelling was carried out in GIS at a pixel level by considering lithology (soil type), structure (depth of soil), slope, relative relief, land use/land cover, and hydrogeology as input factor maps. The obtained susceptibility model was validated using landslides that occurred between 1978 and 2009. The landslide data required for calibration and validation of the susceptibility model were obtained from historical records, including technical reports and railway maintenance records that were available for the 34-year period between 1978 and 2011. Most landslides are shallow translational debris/earth slides and debris flows triggered by rainfall. The landslide susceptibility map prepared using the above-mentioned method demonstrates that about 19 km^{2 areas, located east of Coonoor, and along the slopes encompassing NH-67 and railway, are grouped under "very high" susceptibility class. Between Coonoor and Ooty, some sporadic patches of "very high" category occur around Lovedale, Manthada and Ooty. About 23 km2 area, surrounding the "very high" area is grouped as '"high" susceptibility. Areas with "moderate" susceptibility are distributed as small patches around Bandishola, Wellington, Katteri bend, Indira nagar and Lovedale, whereas areas with "low" and "very low" susceptibility occur along the valley and plateau slopes around Ooty, Ketty, Wellington and Kallar. The dense settlements of Coonoor, Wellington and Ooty town fall in "low" susceptibility class. The susceptibility model presented in this paper could predict about 90% of the landslides in "very high" and "high" susceptibility class. The results provided the qualitative estimate of landslide susceptibility of the study area. The results are of important societal value and can provide inputs for planning risk reduction strategies.}

5 illus, 8 tables, 25 ref

009536   Guhathakurta P;Tyagi A;Mukhopadhyay B (NO, , India Meteorological Dep, Shivajinagar, Pune, Email: pguhathakurta@rediffmail.com) : Climatology at any point : a neural network solution. Mausam 2013, 64(2), 231-50.

Advance knowledge of information on climatology of meteorological parameters like temperature, maximum temperature, minimum temperature, atmospheric pressure, rainfall etc are of great demands from all the users, planners, disaster managements personals, tourism etc. The information is required at the place concerned but this cannot be fulfilled by the meteorological community due to absent of observatory at that place and also some time absent of past data of long period. The present paper has described a comparatively new application of the neural network in the field of spatial interpolation. Neural network interpolation models are developed for both maximum and minimum temperatures for all the twelve months. The model utilizes geographical information like latitude, longitude and elevation as inputs to generate normal maximum and minimum temperatures at a place. The performances of the models are compared with the other commonly used method for spatial interpolation.

11 illus, 5 tables, 49 ref

009535   Goyal S;Mohapatra M;Sharma A K (NO, India Meteorological Dep, New Delhi-110 003, Email: mohapatraimd@gmail.com) : Comparison of best track parameters of RSMC, New Delhi with satellite estimates over North Indian Ocean. Mausam 2013, 64(1), 25-34.

India Meteorological Department (IMD), as a Regional Specialized Meteorological Centre (RSMC) has the responsibility of monitoring and prediction of cyclonic disturbances (CDs) including depressions and tropical cyclone (TC); collection, processing and archival of all data pertaining to CDs and preparation of best track data over the north Indian Ocean (NIO). The process of post-season analysis of CDs to determine the best estimate of a CD's position and intensity along with other characteristics during its lifetime is described as "best tracking". The best tracking procedure has undergone several changes world-over including NIO due to change in monitoring and analysis tools & procedure. However, the geostationary satellite remains the main tool for monitoring of location and intensity of CDs. There have been a few attempts to document the role and extent of satellite estimates in determining the best track location and intensity of CDs over the NIO. Hence, a study has been undertaken to compare the location and intensity of CDs based on best track parameters prepared by RSMC, New Delhi with those estimated by satellite division of IMD based on INSAT and Kalpana satellites. The average difference in location of CDs over the N1O, BOB and AS is about 39, 40 and 37 km respectively. The difference in location is 50 km or less in about 65% of the total cases and about 6% of the cases have a difference of 100 km or more over the NIO as a whole. It is about 62% and 6% over the BOB and about 70% and 5% over the AS respectively. Difference in location gradually decreases with increase in T number. It is about 30 km when the intensity of the system is T4.0 or more (very severe cyclonic storms and above intensity) over the BOB, AS and NIO. Considering the spatial distribution of difference in location of CDs, it is higher near the coast and decreases as we move away from the coast. The intensity in the best track agrees with the satellite estimates in about 85.5% of the cases. While the satellite based intensity is underestimated (Satellite division estimated T number is less than best track T number) in 9.5% cases, it is overestimated (Satellite division estimated T number is greater than best track derived T number) in about 5% cases over the NIO. Considering the spatial distribution, the difference occurs mostly when the CD lies near the coast or the islands in the NIO like the difference in location.

6 illus, 5 tables, 11 ref

009534   Ghoshal T B;Bodas M S;Ghosh S (NO, Geological Survey of India, PSS-P&M Division V, Central Headquarters, 27, J.L. Nehru Road, Kolkata-700 016, Email: saibal.springdale@gmail.com) : Multi-thematic and deterministic-cum-heuristic methodology for mesoscale (1:5,000/10,000) landslide susceptibility zonation. Indian J Geosci 2013, 67(3-4), 217-28.

Multi-thematic and deterministic-cum-heuristic methodology for mesoscale landslide susceptibility zonation is presented in this paper. The suggested methodology states basis to be used for selection of the area, scale requirements, the earth observation data/ topographic maps to be used, importance of Geographic Information System and logical sequence of various stages of investigation in the study. Since failure mechanisms in rocky slopes are different from those in overburden-covered areas, this paper intuitively presents a discerning approach for these two types of slope-forming materials and gives separate rating schemes for them. Recognizing the fact that the mesoscale landslide susceptibility zonation needs to be more terrain-specific and application-oriented; the suggested methodology introduces a novel approach of using Slope Mass Rating in case of rocky slopes and Shear Strength Parameters for overburden-covered areas. Further, the suggested methodology also leaves a scope for recognition of terrain-specific "additional factors" controlling slope instability in a given area and their addition in the scheme of calculation of Total Estimated Susceptibility Values. It thus makes a paradigm shift from knowledge-based descriptive approach, used in BIS guidelines for macroscale landslide susceptibility zonation to a deterministic-cum-knowledge-driven and more flexible methodology. The proposed methodology is still in its nascent stage and its efficacy in delineating landslide susceptible areas on mesoscale needs to be tested and further debated so that a robust methodology can be formulated in future.

1 illus, 4 tables, 5 ref

009533   Ghosh S;Das R;Goswami B (Geological Survey of India, Geohazards Research and Management Cell, 15 A & B, Kyd Street, Kolkata-700 016, Email: saibal.springdale@gmail.com) : Developing GIS-based techniques for application of knowledge and data-driven methods of landslide susceptibility mapping. Indian J Geosci 2013, 67(3-4), 249-72.

Landslides cause frequent disasters in fragile landmass of the Himalayas during almost every monsoon (June-October) with occurrence of different types of failures. For mitigating this hazard, as part of the entire landslide management programme, medium-scale (1:25000/50000) landslide susceptibility mapping remains to be an important geoinformation tool to the planners and administrators for framing land use zoning regulations required to plan, protect and build infrastructure development work in the Himalayas. Several methods of medium-scale landslide susceptibility mapping are available in the literature which is mainly of two types - knowledge-driven or heuristic and data-driven or empirical. In this work, both of these methods were applied simultaneously in highly landslide-prone areas in the Darjeeling District, West Bengal. As heuristic model, BIS method of landslide susceptibility mapping was applied which is a popular method followed in Indian terrain conditions and for the data-driven method Weights of Evidence (WofE) modelling was used in this research. The main objectives of this work are to explore the existing Bureau of Indian Standards (BIS) method and test its efficacy in a GIS platform so that its results can easily be compared with that of any data-driven model. For better and compatible comparison, the fixed geofactors (slope, relief, lithology, land use, structure and geohydrology) as proposed by the BIS method were also used in WofE model in the same area and both the model results are validated with the available record of landslide inventory of pre-2003 period. The comparison reveals that compared to WofE, BIS is a bit less efficient because of adopting a model that uses only fixed geofactors, fixed geofactor classes and pre-defined weights or ratings. However, BIS method is landslide-independent, thus seems to be apparently more intelligent and innovative despite its poor performance compared to WofE. Instead, the WofE method indeed is a more intuitive data-driven technique, to be used in the areas where good quality past landsliding information is available, and bears the possibility of testing the efficacy of individual geofactor portraying the relevance of local terrain conditions. This research strongly recommends an improved analytical; method which relies on pre selection and weighting of relevant geofactors specific to specific landslide types before application of any model of integration for generating landslide susceptibility maps.

12 illus, 6 tables, 35 ref

009532   Dube S K;Poulose J;Rao A D (NO, Indian Institute of Technology, Hauz Khas, New Delhi-110 016, Email: skdube@cas.iitd.ac.in) : Numerical simulation of storm surge associated with severe cyclonic storm in the Bay of Bengal during 2008-11. Mausam 2013, 64(1), 193-202.

Storm surge disasters cause heavy loss of life and property, damage to the coastal structures and the losses of agriculture in India and its neighborhood whenever a tropical cyclone approaches. About 3,00,000 lives were lost in one of the most severe cyclone that hit Bangladesh (then East Pakistan) in November 1970. The Andhra Cyclone devastated the eastern coast of India, killing about 10,000 persons in November 1977. Orissa coast of India was struck by a severe cyclonic storm in October 1999, killing more than 15000 people besides enormous loss to the property in the region. More recently the Nargis cyclone of May 2008 killed about 1,40,000 people in Myanmar as well as caused enormous property damage. These and most of the world's greatest human disasters associated with the tropical cyclones have been directly attributed to storm surges. Thus, provision of precise prediction and warning of storm surges is of great interest in the region. The main objective of the present paper is to highlight the recent developments in storm surge prediction model for the Bay of Bengal and the Arabian Sea. Paper also describes the performance of the model in forecasting/simulating the surges associated with severe cyclones formed in the Bay of Bengal during 2008 to 2011.

6 illus, 42 ref

009531   Datta R (NO, Regional Meteorological Centre, Kolkata, Email: ramkrishna_data@rediffmail.com) : Ocean atmospheric coupled model to estimate energy and path of cyclone near the coast. Mausam 2013, 64(1), 189-92.

It is seen that in the Bay of Bengal or in the Gulf, most of the time the atmospheric phenomena, like, cyclone, hurricane etc. move towards right to its motion. To study such occurrences; we have considered fluid dynamics of ocean coupled with atmospheric motion. In the present study we have considered the eye of the cyclonic system that consist of fluid dynamical source and fluid dynamical sink at a small distance apart, and thus, constitute the fluid dynamical doublet of the object system. Then the fluid dynamical doublet of the object system and its image system has been considered with respect to a firm wall (here the sea shore). The fluid dynamical equation of complex potential with respect to the object system, the image system and the stream velocity have been undertaken. The complex potential of the object doublet, image doublet and the stream velocity have been considered. The velocity vector, consequently the pressure has been retrieve with the help of Bernoulli's equation of fluid motion. Then the minimum /maximum pressure on the wall that is on the sea shore has been calculated analytically. Thus, it is found that on the basis of some prevailing conditions existing wind and energy the cyclone or hurricane move towards the sea coast or to the right of its motion.

7 illus, 7 ref

009530   Chourasia M;Ashrit R G;George J P (National Centre for Medium Range Weather Forecasting (NCMRWF), Ministry for Earth Sciences, A-50, Institutional Area, Phase-II Sector-62, Noida, Uttar Pradesh-201 309, Email: manjusha@ncmrwf.gov.in) : Impact of cyclone bogusing and regional assimilation on tropical cyclone track and intensity predictions. Mausam 2013, 64(1), 135-48.

Aim of this study is to assess the impact of tropical cyclone bogusing in WRF assimilation and forecast system for cyclone track and intensity prediction in short range forecast. The impact is demonstrated in terms of track error, central pressure, and maximum sustained wind speed. The study is based on the three cyclones; namely 'LAILA' (Bay of Bengal), 'GIRI (Bay of Bengal) and 'PHET' (Arabian Sea), formed in the year 2010. The WRF model makes use of the operational NCMRWF T382L64 analysis and forecasts and the model is integrated upto 72 hrs for producing the cyclone track and intensity forecast. Four sets of experiments were performed: (i) The control experiment (CNTL) in which neither assimilation nor cyclone bogusing is done. The model is initialized using interpolated global model analysis, (ii) In assimilation experiment (VAR), model initial condition is prepared using WRF VAR data assimilation system (without cyclone bogusing). (iii) The cyclone bogusing experiment (BOG) featuring cyclone bogusing alone without assimilation. In this case the model first guess is modified using cyclone bogusing and used as the initial condition, (iv) In the forth experiment, the initial condition of the model is prepared with both cyclone bogusing followed with WRF data assimilation (BOGVAR). Results indicate remarkable impact of cyclone bogusing on the initial condition. All three cyclones can be located in the initial conditions (0000 UTC) of bogus (BOG and BOGVAR) experiments which were otherwise absent in no-bogus (VAR and CNTL) experiments. Significant reductions in track errors occurred in BOGVAR experiment. The maximum reduction in track error in BOGVAR compare to VAR is 76.8% in 'LAILA', 87.3% in 'GIRI' and 51.5% in 'PHET' respectively. Maximum sustained wind speed and minimum central pressure are close to observations in BOGVAR compared to VAR for 'LAILA' and 'GIRI'.

43 illus, 4 tables, 7 ref

009529   Chasie M;Theophilus P K;Sarkar N K (Geological Survey of India, Landslide Hazard Zonation Project, Northeastern Region, Shillong-793 003, Email: niroj4@gmail.com) : Medium-scale landslide susceptibility mapping along the strategic national highway corridor of Bomdila-Tawang sector, Arunachal Pradesh, North East India, through heuristic approach. Indian J Geosci 2013, 67(3-4), 289-302.

Study highlighted the landslide susceptibility status of approximately 200 line km of the strategic communication corridor between Bomdila and Tawang of western Arunachal Pradesh which has been brought out through medium-scale (1:50,000) landslide susceptibility mapping. The slope mass along the road corridor was categorized into five susceptibility classes based on a heuristic approach proposed by BIS (modified by GSI, 2005) considering relative weightage of a set of causal factors. The thematic maps on each of the causative factors and landslide incidence map of the studied corridor were prepared through augmentation of field data and baseline information. The Landslide Susceptibility Map (LSM) of the specified road corridor was generated through facet-wise integration of the generated field data in GIS platform pertaining to the lithology, structure, slope morphometry, relative relief, land use, land cover, slope erosion, hydrogeology, landslide incidences and rainfall parameters. Analysis of the generated landslide susceptibility map reveals that 1.8% of the total area studied may be categorized as "Very High" and "High" susceptibility classes. The various other susceptible classes, viz. "Very Low", "Low" and "Moderate" account for 0.1%, 47.91% and 33.89% respectively of the total studied area. Spatial correlation of the various thematic maps with that of the landslide incidence map and LSM of the area indicates that: a) overburden/soil-covered slopes are more prone to failure than that of slopes with bedrocks b) a significantly higher concentration of landslide incidences has been recorded in the vicinity of the prominent regional thrust (MCT) c) a relatively higher concentration of the landslide incidences categorized as "Moderately steep slopes" d) a significantly higher concentration of landslide incidences in the slope "Barren" and "Sparsely vegetated" land cover category e) an overwhelmingly high percentage of landslides/slope failures being initiated due to the extensive slope excavation for widening of the road corridor f) the very high landslide susceptibility in the higher altitude areas of Baisakhi-Se La-Nuranang-Jaswantgarh can be attributed to seasonal and diurnal thawing and freezing effects, snow melting, high anomalous snow and rainfall, wind action, ground vibrations, etc. g) Landslide initiation in the study area has been found to be influenced by both natural triggering factors as well as anthropogenic interferences. The above observations are further corroborated from the spatial distribution of different Landslide Susceptibility (LS) categories vis-a-vis the said related parameters. The generated susceptibility map as such is not static in nature and warrants periodic upgradation in the event of large-scale modification in the slope, unprecedented rainfall (cloudbursts), high magnitude seismic activity (<62>5.0 on Richter scale), etc. The same may be utilized by the planner/road-maintaining authorities for i) perspective planning and estimation of hazard and risk (when combined with temporal database on past rainfall, earthquake, slope failures) ii) taking up environmental regeneration programme in the identified unstable, highly susceptible areas iii) target areas for meso-zonation (1:10,000/1:5,000) and site-specific studies (1:1000/1:2000) iv) a significant contributing parameter for the geo-hazard assessment of the area.

2 illus, 1 table, 6 ref

009528   Chakraborty P K;Chattopadhyay S (NO, Regional Meteorological Centre, Alipore, Kolkata, Email: pk.chakraborty@imd.gov.in) : Hydrometeorological study of a most devastating flood in gangetic West Bengal in september 2000. Mausam 2013, 64(2), 271-5.

9 illus, 2 tables, 6 ref

009527   Chakraborty D (Geological Survey of India, Engineering Geology Division, Central Region, Seminary Hills, Nagpur-440 006, Email: jyoti479@gmail.com) : Stability appraisal of block number 15 of Bichom Dam, Kameng hydroelectric project (package-I), West Kameng district, Arunachal Pradesh using slope mass rating (SMR) technique. Indian J Geosci 2013, 67(3-4), 347-54.

Stability appraisal for 17-m-high cut slope between El. 765 m-748 m and falling within foundation area of Dam Block No. 15 in Bichom Dam, Package-I, Kameng H E Project, has been carried out using Slope Mass Rating (SMR) technique for suggesting slope stability measures. The foundation media of the said dam block comprise inter-banded unit of chlorite-mica schist and quartzite belonging to Tenga Formation of Bomdila Group (Proterozoic Age). Attitude of the foliation recorded within Block No. 15 is N090°-120°/45°-68<144> → N180°-210°. It has been observed that the given cut slope hosts a slope break in its middle. Hence, for the purpose of stability appraisal, the given cut slope has been studied in two slope segments lower and upper. Markland test for both the slope segments has been carried out and unfavourable plane/ wedges have been identified. An unfavourable wedge cluster has been picked up for both upper and lower slope segments having attitude 40°-44°→N050<144 >-052° and 40°-44°→N048<144 >-052°, respectively. Considering planar failure (with respect to joint set, J₂), the SMR study for upper slope segment indicated value of 31 (Class IV, unstable, bad slope condition) while for similar failure mechanism the value for lower slope segment was 34 (Class IV). In case of wedge failures, SMR value for upper slope segment ranged between 12-19 (Class V, completely unstable, very bad slope condition), while the same for lower slope segment ranged between 15 to 22 (Class V to Class IV). Support measure recommended for SMR Class IV is systematic shotcrete, anchors, construction of toe walls or concrete drainage, while that for SMR Class V is gravity or anchored wall/ re-excavation. A tentative anchoring direction has been suggested considering only the unfavourable wedge clusters for both slope segments. It has been further recommended that length, optimum angle of anchoring, its bearing of drive and spacing tnay be evaluated and implemented by project engineers considering cut-slope angle, rockmass class and other necessary site parameters.

5 illus, 1 table, 8 ref

009526   Biswas H R;Kundu P K;Pradhan D (NO, Regional Meteorological Centre, Kolkata, Email: 786hrb@gmail.com) : Case study for cyclone 'AILA' for forecasting rainfall using satellite derived rain rate data. Mausam 2013, 64(1), 77-82.

Major threat to the life and property of people on the east coast of India, including West Bengal Coast, is due to very heavy rainfall from landfalling tropical cyclones originated over Bay of Bengal. Forecasting magnitude of rainfall from landfalling tropical cyclones is very difficult. Satellite derived rain rates over the raining areas of tropical cyclones can be used to forecast potential tropical cyclone rainfall accumulations. In the present study, an attempt has been made to estimate 24 hours rainfall over coastal stations before landfall of tropical Cyclone 'Aila' using Tropical Rainfall Measuring Mission (TRMM) satellite rain rates data and observed storm track of Aila. Forecast Tropical Rainfall Potential (TRaP), 24 hours prior to landfall for the tropical cyclone 'Aila' based on well known technique developed in USA, provides a good rainfall forecast especially for the coastal areas lying at the head of direction of the storm.

7 illus, 1 table, 8 ref

009525   Bishwapriya A;Gajbhiye P K;Sharma V K;Dhakate M V (NO, Geological Survey of India, State Unit: Patna-800 020, Email: akhouri123@rediffmail.com) : Preliminary assessment of disaster-affected areas of Pithoragarh district, Uttarakhand (post landslide/flood disaster of June, 2013). Indian J Geosci 2013, 67(3-4), 329-36.

Various pertinent contributing factors like high relief, adverse inclination of discontinuity planes of existing geological setup, intense and high rainfall, flash floods, snowfall/avalanches and earthquakes make the fragile Himalayan ranges highly prone to landslides. The excessive human interference with nature has also contributed greatly to the degradation of the Himalayan ecosystem. These agents of nature, though greatly varying in magnitude, space and time have caused great miseries to the inhabitants in terms of loss to life and property, loss of infrastructure, disruption and damage to communication/ transportation routes, etc. in turn jeopardizing normal life. During 15 -17 June 2013, the state of Uttarakhand witnessed the severest nature's fury as it was hit by arguably the most devastating natural disasters recorded in recent past. The nature suddenly played havoc through incessant rains particularly in the higher reaches of the Uttarakhand Himalayas causing severe flooding along some of the major rivers. The disastrous effect was not only confined to a particular sector, but covered a wide span of the state. The flooding along the major rivers of Uttarakhand caused severe damage to life and property in several districts of the Garhwal and Kumaon region. The Pithoragarh district, bordering the Nepal territory, was amongst the most affected and the region experienced approximately 400 mm rainfall during June 2013, most of the precipitation occurring on the dates when the disaster occurred. The prominent glacial-fed rivers of the district namely Dhauliganga, Goriganga and Kali Ganga with their unprecedented discharge swept away many transportation routes and settlements close to the river banks and initiated new landslides and reactivated the old ones causing severe damage to life and property. The high-cost infrastructure of the region particularly hydro schemes/ project, bridges and defense establishments, etc. also suffered major setback, thus raising doubts to their safety in the fragile Himalayan geo-environment. An assessment of the hazard-affected areas in the district was carried out identifying fresh zones of mass wasting and an inventory of their geo-parametric details was prepared. Studies reveal that the predominant mass-wasting processes involved are - landslide, river bank erosion and land subsidence. Bank erosion by intense river cutting, wherein sudden gush of sediment-laden high-velocity current has eroded/ completely washed away mainly river-borne terraces (T₀-T₂), along with settlements located on them, has been the most pronounced. Old subsidence zones have been further aggravated and movement along the slopes has been catalysed due to toe cutting by the incessant discharge and flash floods in rapid time.

4 illus, 1 table, 2 ref

009524   Bhatt C M;Rao G S;Asiya Begum;Manjusree P; Sharma S V S P;Prasanna L;Bhanumurthy V (RS Applications Area, Disaster Management Support Division, National Remote Sensing Centre, Indian Space Research Organisation, Balanagar, Hyderabad-500 037, Email: cmbhatt@nrsc.gov.in) : Satellite images for extraction of flood disaster footprints and assessing the disaster impact: Brahmaputra floods of June-July 2012, Assam, India. Curr Sci 2013, 104(12), 1692-1700.

Satellite images provide information on the flood disaster footprints, which is essential for assessing the disaster impact and taking up flood mitigation activities. The Brahmaputra floods that occurred during June-July 2012 devastated a large part of Assam. This article discusses the maximum spatial extent affected due to the flood event, villages marooned and population affected, with the aid of multi-temporal satellite images coupled with the hydrological observations and freely available gridded population data. The study shows that about 4.65 lakh ha area was submerged, 23 of the 27 districts in Assam had more than 5% of the total geographical area submerged, about 3829 villages marooned and 23.08 lakh people were affected. Identification of the spatial extent of areas most vulnerable to flooding, captured from the satellite images acquired during the peak flood period will be helpful for prioritizing appropriate flood control measures in the flood-affected regions.

5 illus, 2 tables, 23 ref

009523   Bhatia R C;Sharma A K (NO, , Block 4/24, Old Rajinder Nagar, New Delhi) : Recent advances in observational support from space-based systems for tropical cyclones. Mausam 2013, 64(1), 97-104.

Capabilities of meteorological satellites to provide vital observations on Tropical Cyclones (TC) are well known since more than last four decades. Most important are the frequent pictures of earth's cloud cover in the visible, IR and water vapour channels obtained from Geostationary meteorological satellites together with the capability of generating a number of quantitative products from these data. R&D efforts of last several years at the Cooperative Institute of Meteorological Satellite Studies (CIMSS), Wisconsin University, USA have culminated into development of an Advanced Dvorak's Technique (ADT) for automatic analysis of Tropical Cyclones. It is in operational use for analysis of North Atlantic and Caribbean Sea cyclones. It has been used on experimental basis at Satellite Meteorology Center, IMD while the conventional Dvorak Technique (DT) works well over the Indian seas, experience of using ADT does not permit at present its use on operational basis over our region. R&D efforts of last several years at CIMSS have also resulted in lot of improvements in the Quantitative products derived from the satellite data. These products have certainly improved the analysis of TC and have provided useful information for predicting the future intensity/movement of TCs. Quality of currently operational products from Indian satellite data is limited by the coarser resolution of the instruments. With the availability of much better quality of data from the new satellite of INSAT series from year (2013) onward there is a good possibility of making further improvements in the quality of products. Data obtained from microwave based instruments also provides useful additional information for TC analysis. The warm core anomaly in the upper troposphere is a useful indicator of the TC intensity.

33 ref

009522   Balaji Kumar S;Krishna Reddy K (Semi-arid-zonal Atmospheric Research Centre (SARC), Yogi Vemana Univ, Kadapa-516 003, Email: krishna.kkreddy@gmail.com) : Rain drop size distribution characteristics of cyclonic and North East monsoon thunderstorm precipitating clouds observed over Kadapa (14.47°N, 78.82°E), tropical semi-arid region of India. Mausam 2013, 64(1), 35-48.

Raindrop size distributions (RSD) of "JAL" Cyclone induced precipitating clouds (7 Nov. 2010) and North- East (NE) monsoon thunderstorm precipitating clouds (16 November 2010) were measured with a Particle Size and Velocity (PARSIVEL) disdrometer deployed at Kadapa (14.47°N; 78.82°E), a semiarid continental site in Andhra Pradesh state, India. From the observational results we find that stratiform precipitation is predominant than convective precipitation in cyclone induced precipitation clouds. Where as in the case of NE monsoon thunderstorm precipitation convective cloud fraction is more than stratiform clouds. The cyclone induced precipitation is associated with higher concentration of small drops (small and middrops) in stratiform region (conveptive region) than NE monsoon precipitation. The average mass weighted diameter, Dm of cyclone induced precipitation is less than the NE monsoon precipitation both in stratiform and convective cloud regions. The observed RSD are found distinctly vary from cyclonic and NE monsoon thunderstorm precipitating clouds.

11 illus, 1 table, 18 ref

009521   Balachandran S (India Meteorological Dep, Regional Meteorological Centre, Chennai, Email: balaimd@gmail.com) : Barotropic energetics analysis of tropical cyclone Khai Muk. Mausam 2013, 64(1), 49-58.

Analysis of dynamical conditions in respect of formation and growth of tropical cyclone Khai Muk over the Bay of Bengal during 11-14 November 2008 is discussed with focus on barotropic energy conversion at lower level. It is observed that the extension of subtropical easterlies from the Western Pacific in to central Bay of Bengal to the north and equatorial westerlies to the south of ITCZ during the above period constituted a large scale horizontal shear flow. This led to generation of cyclonic shear vorticity and initiation of disturbance which later developed in to tropical cyclone Khai Muk. The basic zonal flow in the lower troposphere was barotropically unstable as depicted by change of sign of meridional distribution of absolute vorticity which provided the kinetic energy for the growth of eddy. There existed positive correlation between mean zonal flow and the meridional gradient of absolute vorticity which favoured increase of eddy kinetic energy through barotropic eddy-mean flow interactions. Energetic analysis indicated that areas of high rate of positive change of eddy kinetic energy coincided with positive areas of barotropic conversion and the magnitude of barotropic conversion matched with local rate of change of eddy kinetic energy around the area of vortex generation. Barotropic energy conversion by meridional shear of basic zonal flow was an important energy source for the formation and initial growth of tropical cyclone Khai Muk.

9 illus, 14 ref

009520   Ashok Kumar;Mitra A K;Bohra A K;Iyengar G R; Durai V R (NO, National Centre for Medium Range Weather Forecasting (NCMRWF), A-50, Institute Area, Sec-62, Noida, UP-201 307, Email: ashok@ncmrwf.gov.in) : Multi-model ensemble (MME) prediction of rainfall using canonical variates during monsoon season in India. Mausam 2013, 64(2), 211-20.

The prediction of Asian summer monsoon rainfall at various space-time scales is still a difficult task. Compared to mid-latitudes, proportional improvement in the skill in prediction of monsoon rainfall in medium range had been less in recent years. Global models and data assimilation techniques are being further improved for monsoon and tropics. However, multi-model ensemble (MME) forecasting is gaining popularity, as it has the potential to provide more information for practical forecasting in terms of making a consensus forecast and reducing the model uncertainties. As major centres are exchanging the model output in near real-time, MME is a viable inexpensive way for enhancing the forecast skill. During monsoon 2009, apart from simple ensemble mean, the MME predictions of large-scale monsoon precipitation in medium range was carried out NCMRWF/MoES, India. The canonical variates technique is used for it. The skill scores are computed, which indicate that multi-model ensemble forecast has higher skill than individual model forecasts and also higher than the simple ensemble mean in general. Although the skill of the global models falls beyond day-3, but a significant improvement could be seen by employing the MME technique up to day-5.

5 illus, 24 ref

009519   Ansari M I;Kundu S K;Saikrishnan K C;Madan R (NO, , India Meteorological Dep, Lodi Road, New Delhi-110 003, Email: mdimran_ansari@yahoo.com) : Measurement and analysis of refractive index structure constant C₂<. Mausam 2013, 64(2), 363-70.

The radio refractivity is an important factor which effects radio wave propagation. Radio refractivity depends upon the physical states of atmosphere, i.e., its temperature, pressure and humidity. Radars are sensitive to refractive index irregularities on scale size equal to half wavelength of Radar. Backscattered power is dependent on the magnitude of refractive index structure constant C_n^{2. Hence C_n2 values of a place are useful for designing weather radar specially wind profiler radars. This paper is an attempt to map the profile of refractive index structure constant C_n2 of atmosphere in the upper atmosphere, over Delhi on diurnal and seasonal basis.}

7 tables, 6 ref

009518   Ali M;Singh U P;Joardar D;Nizamuddin (NO, , Airport Meteorological Office, Jaipur, Email: mehfoozali.syed@gmail.com) : Synoptic study of extremely heavy rainfall events over lower Yamuna catchment: some cases. Mausam 2013, 64(2), 265-80.

Extreme rainfall results in landslides, flash flood and crop damage that have major impact on society, the economy and the environment. During southwest monsoon season, flood mostly occurs in India due to extremely or very heavy ram that originates from environmental and synoptic conditions. An attempt has been made to identify the main synoptic reasons, which are responsible for extremely heavy rainfall events over Lower Yamuna catchment (LYC) through the analysis of the relationship between this rainfall and atmospheric systems for the period 1998-2010 based on modern observational technology and developed forecasting technique in the field of short range prediction. The finding of this study show that the major factor have is the arrival of Bay of Bengal low pressure systems in this region, of course if the ascent local conditions such as heat occur, causing the heaviest rains there. The low pressure systems (LPS like, Cyclone, depression, low pressure area etc.) developed generally over Bay of Bengal moved in west to north-westwards direction and reached over the LYC region. Also LPS may be formed in situ under the influence of upper air cyclonic circulation (cycir) responsible for such events. Such system yield extremely heavy rainfall events (generally in the south-west sector of the system) at isolated places and heavy to very heavy rainfall at a few places and there by caused flood situation. The possibility of occurrence of such type of rainfall would be higher if the LPS is either stagnate or slow over LYC region. The NWP products of RSMC (IMD) New Delhi forecast contours / wind charts for 72, 48 & 24 hrs were found good tool for accurate forecast position of the movement of the LPS. Such information certainly facilitate to forecaster in prediction of extreme rainfall events more accurately so that district authorities may set up necessary infrastructures for disaster preparedness in time.

10 illus, 20 ref

009517   Adlakha V;Patel R C;Lal N;Mehta Y P;Jain A K; Ashok Kumar (Geophysics Dep, Kurukshetra Univ, Kurukshetra-136 119, Email: patelramesh_chandra@rediffmail.com) : Tectonics and climate interplay: exhumation patterns of the dhauladhar range, northwest himalaya. Curr Sci 2013, 104(11), 1551-9.

New apatite and zircon fission-track ages from the Dalhousie Granite exposed along Dhauladhar Range, Northwest Himalaya extend from 2.9 ± 0.2 to 4.4 ± 1.0 Ma and 10.4 ±1.4 to 21.1 ± 2.2 Ma respectively. One-dimensional thermal modelling of the data suggests slow exhumation during Middle to Late Miocene, followed by acceleration during Plio-Pleistocene. The activity along the Panjal Thrust (PT)/Main Central Thrust (MCT) in this region ceased at <126>15 Ma, while tectonic activity along the Main Boundary Thrust (MBT) started prior to <126>10 Ma. Tilting of topography due to activation of MBT controls the exhumation pattern of Dalhousie Granite during Middle to Late Miocene. Correlation among structure, topographic pattern and thermochronometric ages indicates interplay between tectonics and erosion-controlled exhumation along the mountain front. The fast exhumation rates since Pliocene are synchronous with intensification of the Asian monsoon and suggest a causal link between erosion and climate variation for evolution of the landscape.

5 illus, 2 tables, 67 ref

008642   Wadhawan S K;Hariprasad M;Dinesh A C; Karthikeyan M;Varghese S;Drishya G (Central Headquarters, Geological Survey of India, 27, J.L. Nehru Road, Kolkata-700 016, Email: acdinesh@rediffmail.com) : Strategising mineral exploration of offshore obvious geological potential (OGP) areas with exclusive economic zone (EEZ) of India. Indian J Geosci 2013, 67(2), 191-8.

3 illus, 23 ref

008641   Vishnoi B;Nagar A;Sharma K;Ballari C P (NO, , India Meterological Dep, Pune-411 005) : Generation of electrical energy from solar energy on western Rajasthan, an analyis. Mausam 2013, 64(3), 531-8.

Solar radiation recorded by the pyranometer at Jaisalmer and Jodhpur has been analysed and the average of solar radiation monthwise data has been prepared and arranged for 15 years period (1995-2009). The highest collected value of solar energy for both the places was found in the month of May and the lowest in the month of December. Monthwise wind velocity has been classified and arranged in different categories. After analysing all weather parameters it is concluded that the western Rajasthan is the best area for generation of electrical energy from solar energy.

7 illus, 11 tables, 8 ref

008640   Varikoden H;Krishna Kumar K;Babu C A (NO, Indian Institute of Tropical Meteorology, Pashan, Pune, Email: hamza@tropmet.res.in) : Long term trends of seasonal monthly rainfall in different intensity ranges over Indian subcontinent. Mausam 2013, 64(3), 481-8.

In general Indian summer monsoon rainfall did not show any significant trend in all Indian summer monsoon rainfall series, however, it was reported that the ISMR is subjected to spatial trends. This paper made an attempt to bring out long term trends of different intensity classes of summer monsoon rainfall in different regions of Indian subcontinent. The long term trend of seasonal and monthly rainfall were also made using the India Meteorological Department gridded daily rainfall data with a spatial resolution of 1° x 1° latitude-longitude grid for the period from 1st January, 1901 to 31st December, 2003. The summer monsoon rainfall shows an increasing trend in southeast, northwest and northeast regions, whereas decreasing trend in the central and west coastal regions. In monthly scale, July rainfall shows decreasing trend over west coastal and central Indian regions and significant increasing trend over northeast region at 0.1% significant level. During the month August, decreasing trend is observed in the west coastal stations at 10% significant level. In most of the stations, mean daily rainfall shows an increasing trend for low and very high intense rainfall. For the moderate rainfall, the trend is different for different regions. In the central and southern regions the trend of moderate and moderately high classes show increasing trend. And for the high and very high intensity classes the trend is decreasing significantly. In the northeastern regions, above 10 mm/day rainfall shows significantly increasing trend with 0.1% significant level.

6 illus, 22 ref

008639   Tomar M S (M. O. Patiala, Punjab Univ, Campus-147 002, Email: rsrwpatiala@yahoo.in) : Temporal variation of tropopause height and temperature over Patiala during 1999-2004. Mausam 2013, 64(3), 566-8.

8 illus, 4 ref

008638   Singh R;Tewari R K;Ahmad R;Balaram V (Chemical Div, Geological Survey of India, Sector-E, Aliganj, Lucknow-226 024, Email: balaram1951@yahoo.com) : Use of <. Indian J Geosci 2013, 67(2), 141-52.

Internal standards are routinely used with inductively coupled plasma mass spectrometry (ICP-MS) to correct or minimize the impact of signal instability and instrument drift in order to ensure good-quality quantitative analysis. In this study, ^{129Xe which is present in the plasma gas itself is used as an internal standard. Rare earth elements (REE) and few other trace elements, Be, Ge, Mo, In, Sn, Hf, Ta, W, T1 and U in some soil and stream sediment reference samples, and Be, Mn, Fe, Ni, Zn, As, Se, Sr, Mo, Ag, Cd, Sb, Ba and Pb in water reference samples were analysed precisely and accurately by ICP-MS using 129Xe as an internal standard. Fusion dissolution procedure using lithium tetra-borate and lithium meta-borate was adopted for sample dissolution in the case of soil and sediment samples. The novelty of this approach is that no external addition of any reagent to act as internal standard is involved since xenon is present as an impurity in the plasma gas itself. As a result, the possibility of introducing any type of elemental impurities through the addition of an internal standard has been completely avoided as addition of external reagents can affect the accuracy of the determinations, especially, when the analysis for different elements is carried out at extremely low concentrations. Eight soil and stream sediments, two water reference samples and a natural water sample were successfully analysed by the method described here. The accuracies and precisions achieved were markedly better when internal standardization was applied. In general, trace element data in a variety of soil, stream sediment and water samples were obtained with <60> 5% RSD with comparable accuracy in each case, suggesting that this method can be applied routinely for the determination of trace elements in soils, stream sediments and water. In addition, the method has been successfully used for analysis of many trace elements including REE at crustal abundance levels in several soil, stream sediment and water samples under National Geochemical Mapping Programme (NGCM).}

1 illus, 5 tables, 31 ref

008637   Singh R K;Shukla A K (NO, , India Meteorological Dep, New Delhi-110 003, Email: ravi5ravi@yahoo.com) : Macroseismic survey and isoseismal map of september 2011 Sikkim earthquake. Mausam 2013, 64(3), 547-52.

Earthquake of M: 6.8 occurred inland at 1811 hrs (IST) on 18 September, 2011, about 68km northwest of Gangtok, Sikkim (Latitude 27.7 ° N, Longitude 88.2° E) at a deeper depth of more than 50.0 km. Intensity survey conducted through a questionnaire and press reports were used for generation of isoseismal map using geo-statistical analysis tool of ArcGIS. Relationship between Surveyed Intensity (SI) data and Peak Ground Acceleration (PGA) was developed for the region.

4 illus, 3 tables, 7 ref

008636   Singh P K (Environmental Geology Div, Northern Region, Geological Survey of India, Sector -E, Aliganj, Lucknow-226 024, Email: p.singh@gsi.gov.in) : Morphometric characteristics of the Kaswali and Kaila river basins of Kachchh mainland, Gujarat: an indicator of neotectonic behaviour. Indian J Geosci 2013, 67(2), 177-90.

Morphometric analysis of river basins has been utilized by many workers to understand the hydro-geologic nature of the drainage basins and to evaluate the neotectonic behaviour of an area. Northern Hill Range, Kachchh, which is characterised by seismic activities, is marked by Kachchh Mainland Fault (KMF) bounding it in the north. The Kaswali and Kaila river basins are two major river basins draining through the Northern Hill Range and pass through the KMF debouching into the Banni Plain of Rann of Kachchh. Detailed morphometric analysis of the Kaswali and the Kaila river basins was carried out to evaluate the neotectonic activities around the Kachchh Mainland Fault. The drainage of the Northern Hill Range of the Kachchh basin is incisive as evidenced by 45- to 20-m high fluvial cliffs and knick points observed in the long profiles of the rivers. The bifurcation ratios of the river basins indicate that they arise from hilly terrains with high gradient. This ratio is generally higher for lower orders and higher bifurcation ratios may be attributed to the high degree of tectonic activity in the area during Quaternary. The circularity ratio of the Kaswali River basin is 0.426 and that of the Kaila basin is 0.437. The elongation ratio for the Kaswali basin is 0.674 while for the Kaila basin it is 0.646, indicating that the basins are elongated and are tectonically controlled. Drainage density of the river basins of the area may be assigned to high-density class. Since the study area lies in the arid climatic zone, the high density is attributed to neotectonic activity. Texture ratios of basins vary from 6.01 (Kaswali basin) to 9.17 (Kaila basin) which is very high. The high texture ratio is indicative of recent uplift. The ruggedness for the Kaila basin is more than 1 while it is about 0.56 for the Kaswali basin. These values suggest high drainage density and comparatively low relief, indicating neotectonic activity in the area. The Asymmetry Factors calculated for the Kaswali and Kaila basins are 53.11 and 48.94 respectively. The Pseudo Hypsometric Integral of the rivers, in general, is high for the Kaswali and the Kaila basins which indicate that the area has undergone rejuvenation in the recent past. The long profiles of the rivers show prominent breaks in their longitudinal profiles. These breaks are indicative of rejuvenations forming knick points which are strong evidences of neotectonic activity in the area. The convex-up curves with high integrals are typical for youth and disequilibrium stage of the landscape which is characteristic of the Kaswali stream and indicates the influence of the neotectonism in the area. The sinuosity indices for the Kaswali River show that the topographic sinuosity index is 100% in upper reaches whereas it starts decreasing in the middle portion of the rocky plains. The high values of Topographic Sinuosity Index compared to Hydrological Sinuosity Index for the Kaswali indicate that the tectonic factors are dominating over hydraulic factors in shaping the course of the rivers. High texture ratio for Kaila River is indicative of uplift in the basin. The ruggedness of the basins suggests high drainage density over comparatively low relief indicating towards active tectonism in the area.

9 illus, 5 tables, 42 ref

008635   Seetharam K (NO, , Meteorological Centre, Hyderabad, Email: kovelasitaram99@rediffmail.com) : Rainfall analysis over Rayalaseema meteorological sub-division. Mausam 2013, 64(3), 558-65.

8 illus, 5 tables, 9 ref

008634   Samui R P;Balasubramanian R;Kamble M V (NO, , India Meteorological Dep, Pune-411 005, Email: rsamui@yahoo.com) : Northeast monsoon rainfall and agricultural production in Tamil Nadu and Andhra Pradesh : II - dry and wet spell and its impact on cropping pattern. Mausam 2013, 64(3), 489-500.

Rainfall is the only major source that meets the water needs of living beings on earth including agriculture. Due to uncertainty and variability of monsoon rainfall, the agricultural production in dry land agriculture is uncertain. It is not uncommon to experience both inter and intra-seasonal drought in the arid, semi-arid and dry sub humid regions of India causing severe moisture stress. In general, moisture is the major limiting factor for agriculture in the dry land regions of Tamil Nadu and Andhra Pradesh. As climate triggered risks are high for crop production, the knowledge of sequential occurrence and likelihood of wet and dry spells can be used for crop planning and agricultural operations. Thus proper blending of climatic information for the benefit of agriculture could be one of the ways to increase the production. In the present study the initial and conditional probabilities of dry and wet spells over different districts of Tamil Nadu and Andhra Pradesh are worked out. The weekly probability of rainfall with ≥10 and ≥30 mm rainfall per week has been calculated. The initial probability of getting 10 and 30 mm rainfall has been used for fixing the cropping pattern and preparation of land, nursery bed preparation, sowing, transplanting, scheduling of irrigation, application of fertilizers, etc. The study reveals that crops and varieties could be selected through the analysis of dry and wet spell durations with the onset and advance of southwest / northeast monsoon in the given region. When the rainfall commences late during the monsoon, growing period in the region is surely reduced. In Andhra Pradesh, high water requiring crops like paddy and cotton could be selected for the stations in northeast region receiving high rainfall whereas low-water requring crops like pulses, oilseeds and millets are advised for the stations in southwest region receiving poor rainfall. When prolonged dry spell conditions are observed, drought-tolerant crops like groundnut and short duration crops are suggested. This emphasizes the need for understanding rainfall climatology of the region. The study also concludes that depending on the advancement of monsoon and distribution of rainfall for the past few weeks, crops and varieties needs to be selected, taking due consideration of probability of getting wet weeks in future.

2 illus, 7 ref

008633   Roy S S;Saha B K;Hazra S (School of Oceanographic Studies, Jadavpur Univ, Kolkata-700 032, Email: sudeshna.sroy@gmail.com) : Distribution of trace metals in surface water of Bakkhali-Fraserganj and Sagar island offshore, Bay of Bengal, and its implications. Indian J Geosci 2013, 67(2), 159-76.

Chemical parameters of surface water and trace metals therein have been studied in the Bakkhali-Fraserganj and Sagar Island offshore, Bay of Bengal, to understand their effects on the near coastal marine environment. Sea surface temperature at Bakkhali-Fraserganj offshore is 24.5°C-25.2°C during January-February 2009 and at Sagar offshore it is 24.3°C-26.3°C during December 2009. Lower pH (7.6-8.1) at Bakkhali-Fraserganj offshore due to probable presence of organic acids and comparatively higher pH (8.22-8.46) at Sagar offshore showing normal open-ocean pH has been recorded. pH at Henry's Island coast, Namkhana, Kachuberia and Diamond Harbour has been found to be around 8. Salinity at Sagar offshore (16.54-22.5gm/kg) is lower than that at Bakkhali-Fraserganj offshore (22-28gm/kg) probably as it receives large quantity of fresh water from the Hoogly River and its tributaries and distributaries. Salinity decreases in the upstream locations. Dissolved oxygen (DO) in the Bakkhali-Fraserganj offshore (2.9-4.9mg/l) if higher than that in the Sagar offshore (0.98-3.29mg/l). DO increases as we go upstream showing an inverse trend with salinity. Trace metal distribution in the Bakkhali-Fraserganj offshore follows the trend Mn<62>Ni<62>Zn <126> Co<62>Pb<62>Cd<62>Cu and in the Sagar offshore follows the trend Zn<62>Mn<62>Cu<62>Pb<62>Ni<62>Co<62>Cd. The concentrations of most of the trace metals in the studied area are well above the world average found in seawater indicating anthropogenic influence in the area.

25 illus, 3 tables, 18 ref

008632   Ray K;Chincholikar J R;Mohanty M (NO, , India Meteorological Dep, New Delhi-110 003, Email: kamaljit_ray@rediffmail.com) : Analysis of extreme high temperature conditions over Gujarat. Mausam 2013, 64(3), 467-74.

One of the fallouts of the global warming is the increase in frequency of extreme events like cyclones, heavy rainfall, flood, droughts and heat waves etc, across different parts of the world on varying scale/intensity. Climate variability and occurrence of extreme weather events are the major concerns for socio-economic well being of the region. During the period March to May 2010, Gujarat experienced moderate to severe heat wave condition with record number of days with heat waves in most of the districts of Gujarat. This study was undertaken to analyze the decadal climatology of extreme high temperature conditions over Gujarat. The decadal analysis carried out in the study indicated that the number of moderate heat wave days and severe heat wave days are highest in the last decade as compared to earlier three decades in more than 70 per cent of the stations. The districts of Ahmedabad, Baroda, Rajkot, Banaskantha (Deesa) and Sabarkantha (Idar) show increase in moderate heat waves in the last decade (2001-2010). Various IMD Stations like Baroda, Deesa, Kandla and Idar have recorded all time highest temperatures in the last decade. The summer maximum temperature anomalies of five non coastal stations of Gujarat also indicate a high positive anomaly (upto 4 °C) prevalent in the last decade. The paper also analyses the synoptic condition during the severe heat wave of May, 2010.

4 illus, 4 tables, 11 ref

008631   Pillay S;Naidoo K;Bissessur A;Agjee N;Pillay K;Purves B;Pillay R;Ballabh H (School of Agricultural, Earth and Environmental Sciences, Univ of KwaZulu-Natal, Westville Campus, Durban 4000, South Africa, Email: ballabh@ukzn.ac.za) : Sand mining impacts on heavy metal concentrations in two important river systems of Northern Kwazulu-Natal, South Africa. J hum Ecol 2014, 47(2), 155-62.

Sand mining of the bed, banks, riparian zone and floodplains of rivers are known to cause major morphological and hydrological changes that impact both on their functioning and on riverine habitats and biota. In this study, the impacts of sand mining on sediment textural characteristics and heavy metal concentrations of twelve metals (Al, As, Cr, Cu, Fe, Pb, Mn, Ni, P, Ti, V and Zn) and three nutrients, Ca, Mg and P and their impacts for instream and riparian biota are presented for two important river systems, the Mvoti and the Mdloti Rivers of KwaZulu-Natal, South Africa. With the exception of Mn in the Mvoti system, the concentrations of all elements increased downstream of the sand mining operations. This is echoed by the Contamination Factor, Combined Pollution Index, and Pollution Load Index analyses. Enrichment Factor (EF) analysis indicates a slightly variable picture in that metals Pb and Ti for the Mvoti and Cu for the Mdloti as well as nutrients Ca and Mg for the Mvoti and Ca and P for the Mdloti decreased downstream of mining operations. Despite the variable EF, these results clearly highlight the importance of monitoring sediment geochemistry of sand mining operations, particularly for their potential hazardous impacts on downstream habitats.

3 illus, 3 tables, 35 ref

008630   Parashar V K;Sharma S;Saxena R N (Geology Dep, Govt. Motilal Vigyan Mahavidyalaya, Bhopal, Madhya Pradesh) : Impact of nitrogenous fertilizers on the quality of shallow groundwater in the upper alluvial plains of Narmada valley between hoshandabad and bhilaria, M.P.,India. Asian J expl Sci 2013, 27(11), 73-9.

This study has been undertaken to motivate the farmers to use the high nitrate water for irrigation as a substitute of nitrogenous fertilizers available in over a stretch of about 45 kms from Hoshangabad to Bhilaria. The study area falls in the toposheets Nos. 55F/9, 55F/10, 55F/6 which is mostly covered by alluvial plains comprising the mist fringing rock, the Deccan trap lava flows of Basaltic composition of Cretaceous-Eocene age. In order to evaluate the quality, 25 representative groundwater samples from shallow aquifers were collected from the study area. The collected water samples were analised by using the standard methods as proposed by APHA for drinking and agricultural purpose. The result demonstrated that majority of the groundwater samples have nitrate concentration less than 50mg/l and 45 mg/l which is the upper mandatory limit as per water quality guidelines proposed by WHO and Indian Standards Specifications respectively However, few of the samples have nitrate concentration more than the permissible limit which indicates that they are fit for agriculture but not for the drinking purpose. Higher concentration of nitrate in shallow groundwater causes several disease such as methaemoglobinemia (blue baby syndrome), Alzheimer's disease, vascular dementia, netural tube defects and gastro-intestinal cancers. The investigation also suggests that farmers of the study area should be motivated to adopt sprinkler, drip or trickle techniques for irrigation in place of flood irrigation. The farmers of the study area should use proper quality and quantity of fertilizers as per the requirement of the crops and as per manufacturing instructions.

5 tables, 26 ref

008629   Majumdar R K;Samanta S K;Kharkongor V C;Kar S;Deb I (Geological Sciences Dep, Jadavpur Univ, Kolkata-700 032, Email: ranjit_mazumdar2000@yahoo.co.in) : Determination of slip surface in slope failure zones: a geophysical resistivity field approach. Indian J Geosci 2013, 67(2), 117-30.

Present work involves geological and geophysical study to identify the landslide-prone areas and determine slip surface in some parts of Kurseong in eastern Himalayan region. Geoelectric resistivity method has been used for this purpose. The study area comprises Kurseong town and its adjacent areas, which include Aringaley, Ambootia Tea Estate, Upper Paglajhora and Gidda Pahar. The rock type at Aringaley is mostly quartzo-feldspathic gneiss showing strong regional foliation (S₁) along with crenulations cleavages (S₂). In Upper Paglajhora, the rock comprises mainly mica schist showing strong regional schistosity along with crenulation cleavages. The general rock types of Gidda Pahar are mica schists with some bands of quartzite unit. The rock type of Ambootia belongs to the Darjeeling Group of metamorphic rocks. The presence of two sets of foliations in the region makes the rock very weak to get weathered easily. Schlumberger vertical electrical sounding (VES) has been carried out to find the details of subsurface formations or litho units and to identify fractured zones/weak planes based on the variations of their electrical properties and hence, it has been successfully used for slope stability analysis in hilly regions. VES curves are finally interpreted by software 'RESIST' to know the layer parameters, i.e. thickness and true resistivity of each layer by 1D inversion algorithm. The interpreted results from the VES study show that subsurface rock masses at all the locations comprise soil, weathered mica schist and quartzite; VES data for Gidda Pahar (R₃) and Aringaley (R₄ and R5) show scatter along depth confirming these as recent occurrence of landslides which are also supported by field investigation; interpreted VES results for Upper Paglajhora (R₁) and Ambootia (R₂) further show the presence of a low-resistive, thin layer at a depth of 3 m and 11.8m respectively which may act as the slip surface resulting in future landslides. The interpreted VES results are compared with numerical modelling using finite element technique (FEM).

10 illus, 44 ref

008628   Lefort T (NO, Ecole Nationale de la Meteorologie, Meteo-France, Toulouse, France, Email: thierry.lefort@meteo.fr) : Dry-line, nor' westers and tornadic storms over east India and Bangladesh : an operational perspective through synergie, the new IMD forecaster's workstation. Mausam 2013, 64(3), 517-30.

Pre-monsoon is a very challenging period for regional duty-forecasters and those involved in mitigation of severe weather consequences. Indeed, violent thunderstorms producing high winds, large hail and even tornados are common features from March to May in East India and Bangladesh. Taking advantage of SAARC (South Asian Association for Regional Cooperation) research publications, as well as knowledge and practical methodology developed by NOAA's National Weather Service in the Tornado Alley, a methodology is proposed that might help IMD forecasters make the best use of their new workstation SYNERGIE. The case study of the 13 April 2010 severe storm has been chosen for this purpose. More than 140 reported deaths and nearly 500,000 people were left homeless or otherwise affected by the storm. A good comprehension of both synoptic and mesoscale conceptual models is needed; then, aided by appropriate numerical model fields, drawing proper weather symbols on surface analysis charts is an important step towards the building and sharing of local expertise with regional or local forecasters. A graphical analysis is proposed and discussed.

25 illus, 19 ref

008627   Khole M;Sunitha Devi S;Sabade B (NO, , Meteorological Office, Pune-411 005) : Monsoon season (june - september 2012). Mausam 2013, 64(3), 569-84.

6 illus, 4 tables

008626   Kalsi N;Ravi Kiran (NO, , Apt 6a, Tower 8, GPRA, New Moti Bagh, Shanti Path, New Delhi-110 021, Email: nkkalsi@gmail.com) : Greater Mohali region: geopolitical impact on urban anthropology to emerge as a significant tri-city entity. J hum Ecol 2014, 47(2), 125-37.

This paper attempts to study the factors responsible for shaping the urban anthropology of Greater Mohali Region in the State of Punjab. The regional destiny was a direct outcome of unparalleled political upheavals of colossal proportions. The settlement pattern was strongly impacted by the geopolitical dynamics that contoured the urban anthropology of Chandigarh-Mohali-Panchkula region which evolved to form the Tri-City. These mayhems churned the life and times of original and mostly migrated habitants and left a deep imprint on the lives and times of people living in the region or those who chose to make it their home by compulsion of circumstances. Novel architectural language and planning parameters gave definite shape and impacted its fortune which was later refined by consequent economic, administrative and political forces, arising out of geopolitical events. This paper focuses on the urban Anthropological aspects that lead to the emergence of Greater Mohali Region as an important component of the Tri-city. The study attempts to cover in depth analysis of geo-political factors facilitating its emergence as Tri-city, the other two being Chandigarh and Panchkula.

3 illus, 1 table, 19 ref

008625   Jeere D S;Kundu A (NO, Geological Survey of India, Alandi Road, Pune-411 006, Email: dsjeere@gmail.com) : Microprobe geochronology of monazite from chromitite of precambrian mafic-ultramafic rocks of vagde area, Sindhudurg district, Maharashtra, India. Indian J Geosci 2013, 67(2), 131-40.

Mafic-ultramafic suite occurring as dismembered bodies within gneiss-migmatite terrain of Vagde area is considered to be the northern continuity of Western Dharwar Craton. Reported chromite mineralisation and abandoned mine pits exist in ultramafic bodies. Chrome spinel compositions suggest that the mafic-ultramafic suite is comparable with stratiform complexes/ layered-intrusion type. Microprobe age dating of unusually occurring monazite in the chromitite band associated with chromian clinochlore has been done and the probable cause for this association has been discussed. Based on Th concentration, mineralogical association and geological set up, it is concluded that the monazite crystallised from hydrothermal solutions that precipitated chromian clinochlore as alteration product in the interstices of chrome spinel within the mafic-ultramafic bands. The probable source of the hydrothermal solutions could be the spatially associated biotite-granodiorite and porphyritic granite gneisses. The chemical dating of monazite has given age of 1790±41 Ma reflecting the age of hydrothermal alteration of the chromitite and therefore the minimum age of emplacement of the mafic-ultramafic suite.

8 illus, 1 table, 18 ref