Search

Soil-to-air heat exchanger concept is one of the efficient methods to reduce the cooling effort required for any air conditioning system. In this paper, a theoretical model of soil-to-air heat exchanger has been developed to predict the air temperature in the outlet of the system during a hot atmospheric condition. This theoretical model is used to predict the sub-soil temperature for a specific ambient condition in a southern part of India and also compared with the measured sub-soil temperature. Performance of the soil-to-air heat exchanger system has been calculated during peak hours in summer and found to have the potential to reduce the energy required to cool the building. [ABSTRACT FROM AUTHOR]

In slope stability analysis, identification of the mechanism behind slope failure is the key factor during the study. Rock mass characterization and kinematics analysis, like geotechnical investigation methods, are not infallible all the time for the weathered slopes. The presence of different grades of weathered mass on the slope profile acts independently to influence the overall failure pattern. Numerical analysis by finite element method (FEM) is evolved as a primary slope stability analysis tool by overcoming the limitations of the stratified weathered materials on the slope. The paper focuses on the stability analysis of railway-cut laterite slopes of the Eastern Ghats of India. The medium to high-grade metamorphism, followed by physio-chemical weathering, favours the region for more prone to failure. The Force Equilibrium Model and Moment Equilibrium Model have been considered to determine the possibility of independent failure events for the probability analysis. Monte Carlo's probability simulation method has delivered a better result for the weathered slopes by taking many variables for the studied region. A compression study has been made between the outcomes of slope stability analysis methods and the probability analysis models, which provides a comprehensive list of factors to understand the failure mechanism of weathered slopes. [ABSTRACT FROM AUTHOR]

The seismic slope stability analysis of the right abutment of a railway bridge proposed at about 350 m above the ground level, crossing a river and connecting two huge hillocks in the Himalayas, India, is presented in this paper. The rock slopes are composed of highly jointed rock mass and the joint spacing and orientation are varying at different locations. Seismic slope stability analysis of the slope under consideration is carried out using both pseudo-static approach and time response approach as the site is located in seismic zone V as per the earth quake zonation maps of India. Stability of the slope is studied numerically using program FLAC. The results obtained from the pseudo-static analysis are presented in the form of Factor of Safety (FOS) and the results obtained from the time response analysis of the slope are presented in terms of horizontal and vertical displacements along the slope. The results obtained from both the analyses confirmed the global stability of the slope as the FOS in case of pseudo-static analysis is above 1.0 and the displacements observed in case of time response analysis are within the permissible limits. This paper also presents the results obtained from the parametric analysis performed in the case of time response analysis in order to understand the effect of individual parameters on the overall stability of the slope. [ABSTRACT FROM AUTHOR]

While the Bourdieusian concepts of capital and relational configurations of positions and position-takings have recently been fruitfully employed to theorize global fields, this paper argues that the concepts of illusio and doxa are especially conducive to analyzing the globalization of a field as an expansion into and transformation of formerly independent national arenas. In deploying the concept of illusio as a (quasi-libidinous) investment in the game, globalization is here first and foremost framed as a process in which more and more actors in various contexts ‘succumb’ to specific field logics that orient them to transnational structures. By emphasizing the concept of doxa as the taken-for-granted fundamentals of a field, the paper furthermore calls attention to the mechanisms that help forge and globalize the tacit presuppositions and shared ontologies on which such logics build. Focusing on a field of global Christian missions that emerged during the nineteenth century, the paper illustrates how its competitive logic of proselytization was introduced into the religious arena of India. It highlights how Western notions of religion gained ground among local traditions and pulled them into a game in which numerical relations of adherents mattered. [ABSTRACT FROM AUTHOR]

Run-of-the-river hydropower projects are developed based on the concept of sustaining reservoir life by sediment management. Sediment management is achieved by sluicing or drawdown flushing through low-level spillways. Simulations with numerical and physical models are essential for optimizing the design and operation of such projects. In this paper, numerical and physical model simulations carried out for sediment management of a run-of-the-river hydropower project are presented. For Devsari Hydroelectric Project, Uttarakhand, India, a physical model was constructed to a geometrically similar scale of 1: 60. Experiments were carried out for sediment management for various scenarios. One-dimensional model Hydrologic Engineering Center's –River Analysis System was used to simulate the longitudinal sedimentation and velocity profiles in the physical model. The numerical model was further applied to the prototype for predicting the long-term sediment deposition along the reservoir stretch. Results of the simulation indicated deltaic sediment deposition in the upstream reaches of the main Pinder and Kailganga rivers. The delta advanced towards downstream for lower reservoir operation levels. The flow velocities in the entire reservoir stretch were observed to be very low, thus confirming the design concept of reservoir functioning as a desilting basin. Experiments were carried out on the physical model for simulating sediment removal by drawdown flushing. It was observed that reservoir capacity can be restored by annual flushing during peak flows. Flushing with discharge of 300 m3/s for 12 h duration can remove about 0.0086 Mm3 of sediment and hence may be adopted for reservoir operation. [ABSTRACT FROM AUTHOR]

This paper deals with the mathematical modeling of the second wave of COVID-19 and verifies the current Omicron variant pandemic data in India. We also we discussed such as uniformly bounded of the system, Equilibrium analysis and basic reproduction number R 0 . We calculated the analytic solutions by HPM (homotopy perturbation method) and used Mathematica 12 software for numerical analysis up to 8th order approximation. It checked the error values of the approximation while the system has residual error, absolute error and h curve initial derivation of square error at up to 8th order approximation. The basic reproduction number ranges between 0.8454 and 2.0317 to form numerical simulation, it helps to identify the whole system fluctuations. Finally, our proposed model validated (from real life data) the highly affected five states of COVID-19 and the Omicron variant. The algorithm guidelines are used for international arrivals, with Omicron variant cases updated by the Union Health Ministry in January 2022. Right now, the third wave is underway in India, and we conclude that it may peak by the end of May 2022. [ABSTRACT FROM AUTHOR]

This paper examines an issue concerning the simulation of anomalously wet Indian summer monsoons like 1994 which co-occurred with strong positive Indian Ocean Dipole (IOD) conditions in the tropical Indian Ocean. Contrary to observations it has been noticed that standalone atmospheric general circulation models (AGCM) forced with observed SST boundary condition, consistently depicted a decrease of the summer monsoon rainfall during 1994 over the Indian region. Given the ocean-atmosphere coupling during IOD events, we have examined whether the failure of standalone AGCM simulations in capturing wet Indian monsoons like 1994 can be remedied by including a simple form of coupling that allows the monsoon circulation to dynamically interact with the IOD anomalies. With this view, we have performed a suite of simulations by coupling an AGCM to a slab-ocean model with spatially varying mixed-layer-depth (MLD) specified from observations for the 1994 IOD; as well as four other cases (1983, 1997, 2006, 2007). The specification of spatially varying MLD from observations allows us to constrain the model to observed IOD conditions. It is seen that the inclusion of coupling significantly improves the large-scale circulation response by strengthening the monsoon cross-equatorial flow; leading to precipitation enhancement over the subcontinent and rainfall decrease over south-eastern tropical Indian Ocean-in a manner broadly consistent with observations. A plausible physical mechanism is suggested to explain the monsoonal response in the coupled frame-work. These results warrant the need for improved monsoon simulations with fully coupled models to be able to better capture the observed monsoon interannual variability. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a new approach to solve the hydro-thermal unit commitment problem using Simulated Annealing embedded Evolutionary Programming approach. The objective of this paper is to find the generation scheduling such that the total operating cost can be minimized, when subjected to a variety of constraints. A utility power system with 11 generating units in India demonstrates the effectiveness of the proposed approach; extensive studies have also been performed for different IEEE test systems consist of 25, 44 and 65 units. Numerical results are shown comparing the cost solutions and computation time obtained by conventional methods. [Copyright &y& Elsevier]

general neural network based methodology that has the potential to replace the computationally-intensive site-specific seismic analysis of structures is proposed in this paper. The basic framework of the methodology consists of a feed forward back propagation neural network algorithm with one hidden layer to represent the seismic potential of a region and soil amplification effects. The methodology is implemented and verified with parameters corresponding to Delhi city in India. For this purpose, strong ground motions are generated at bedrock level for a chosen site in Delhi due to earthquakes considered to originate from the central seismic gap of the Himalayan belt using necessary geological as well as geotechnical data. Surface level ground motions and corresponding site-specific response spectra are obtained by using a one-dimensional equivalent linear wave propagation model. Spectral acceleration values are considered as a target parameter to verify the performance of the methodology. Numerical studies carried out to validate the proposed methodology show that the errors in predicted spectral acceleration values are within acceptable limits for design purposes. The methodology is general in the sense that it can be applied to other seismically vulnerable regions and also can be updated by including more parameters depending on the state-of-the-art in the subject. [ABSTRACT FROM AUTHOR]

An extraction method for deep-seated thick seam deposits by underground mining with high resource recovery has remained a great challenge for Indian mining engineers, whereas the longwall top coal caving (LTCC) method has evolved as an effective method for various geo mining conditions in China and other counties. The percentage of top coal recovery (TCR) plays a predominant role in determining the feasibility of LTCC, which relies on the First Top Coal Caving Distance (FTCD). In this paper, the critical geotechnical parameters are identified, numerically simulated, and statistically analyzed, and the FTCD for Indian geo-mining conditions is developed and validated. A financial assessment is conducted, considering 70% top coal recovery at 85% performance level, cost of production escalated by 20% and fall in coal grade by two grades. The internal rate of return (IRR) for LTCC is 30.24% as per the sensitivity analysis where it is only 18% in single pass longwall method. This study contributes to evaluating both the technical and economic feasibility of introducing LTCC in Indian geo-mining conditions. [ABSTRACT FROM AUTHOR]

The present paper deals with different empirical methods and finite element method of slope stability analysis along National Highway (NH)-7, in Uttarakhand, India. The highway is only path in the hilly terrain of Lesser Himalayan for the public transport and have strategic importance due to militaries possession routes. This route is also significant due to having many holistic places, connecting to this. There was numerous landslides happened along the Highway in past due to various natural and anthropogenic activities. Hence, keeping an eye to the socio-economic development of the distant area, slope stability analysis is very crucial along the road cut sections. To identify the vulnerable locations and to collect the geotechnical data, the field investigation was carried out between Shivpuri to Byasi along NH-7 in Garhwal, Uttarakhand. Then geotechnical data was intended followed by rock mass characteristic, kinematic analysis and Qslope stability. Additionally, to review the stability results, numerical simulation (finite element method) was employed and slope mass behavior and failure mechanism of cut slopes were also evaluated. The rock mass characteristic and kinematic analysis illustrate normal and good variety of rock mass mainly wedge mode with flexural toppling of failure. The slope mass rating, continuous slope mass rating and also Qslope stability analysis showed, road cut slopes are critically stable and unstable. The results of different empirical methods shows a decent correlation between them. Further the numerical simulation analysis also evaluates that two cut slopes are unstable and other one is critically stable. This substantial empirical and numerical analysis of cut slopes provides a collective approach to stable and develop the holistic road corridor in Himalayan terrain. [ABSTRACT FROM AUTHOR]

• Extensive geotechnical characterization of the soil from landslide slip surface helps evaluate the failure mechanism of landslide. • High-intensity rainfall, unplanned vertical cuts and slopes have witnessed the loss of lives and substantial monetary losses during the southwest monsoon in Kerala, India, in 2018. • Importance of locally available sustainable green martial uses in engineering practices. • The numerical analysis confirmed that the vertical cut stabilization with coir geotextiles is safe during high-intensity rainfall. This paper presents laboratory and numerical analysis of vertical cut failure due to rainfall-induced landslide resulting in building failure that led to the death of nine people in Kerala, India, on August 15, 2018. The residual shear strength parameters are evaluated by the ring shear test. The soil water characteristics curve (SWCC) is developed by unsaturated soil strength parameters. The slope stability and infiltration analysis are carried out with limit equilibrium and finite element methods, respectively. The infiltration analysis is carried out by considering three different rainfall patterns on the slope as low, medium, and high intensities. The study includes a two-stage numerical analysis of vertical cut. Firstly, vertical cut analysis with and without rainfall effects and second, the analysis of vertical cut using coir geotextile as reinforcement with rainfall effects. The study emphasized the utilization of locally available coir geotextiles as a reinforcement for slope stabilization. [ABSTRACT FROM AUTHOR]

Tides play a vital role in coastal hydrodynamics, and it is important to understand their complex characteristics in the coastal areas of creeks, bays, estuaries and gulf. In this study, the spatial variation of heterogeneous friction coefficients and their influence on the variation of different tidal constituents (K1, M2, N2, O1, P1 and S2) along Gulf of Khambhat, west coast of India, were studied. A two-dimensional finite element-based numerical model was developed and zones of different friction coefficients were identified by comparing numerically estimated tidal levels and currents with that of measured and reported by earlier studies. Based on the comparisons, the gulf was divided into five zones of different bottom friction values. The numerical model, assigned with friction coefficients, was used to map the contours of selected tidal constituents. From the results, it was observed that two constituents, M2 and K1, influence the hydrodynamics, significantly. The description of the numerical model, calibration, validation and results are presented in this paper. [ABSTRACT FROM AUTHOR]

The summer monsoon season contributes about 80% of annual rainfall in the highly populated region of north India. The teleconnections moderating the variation of summer monsoon rainfall in this region are not satisfactorily understood. A pathway of the equatorial central Pacific sea surface temperature (PSST) influences the north India summer rainfall is revealed from the high‐resolution, more reliable, and state‐of‐the‐art 41‐year (1979–2019) observational data analysis and numerical experiment. The rise in PSST intensifies convection over the equatorial central Pacific with compensatory subsidence over the western equatorial Pacific. Consequently, a much broader and intense anomalous convergence is developed at the upper‐troposphere, which subsequently intensifies the Asian subtropical westerly jet‐stream. The Asian jet intensification strengthens the tropospheric wind shear at north India, as the low‐level monsoonal winds are easterlies over there. The strong wind shear restricts the convective activities in north India. These results are also confirmed using the CFSv2 model sensitivity experiment and a case study of the year 2010. [ABSTRACT FROM AUTHOR]

Abstract: The paper presents valuing of qualitative and quantitative travel attributes influencing the attractiveness of suburban train service in Mumbai city, India. A stated preference experiment is designed to capture the data of sub-urban train mode choice behavior. The behavioral data are analyzed using different modeling techniques such as multinomial logit (MNL) and mixed logit (ML). In ML model, the random parameters are assumed to follow constrained triangular distribution, where mean equals its spread. The decomposition of preference heterogeneity around the mean estimate of random parameter is also investigated using ML model. The study shows the influence of headway time and train ride time associated with a particular crowding level (expressed in density of standing passengers/m2) in choosing the sub-urban train mode by calculating their willingness-to-pay (WTP) values and highlights the importance of WTP for addressing policy issues in the reduction of in-vehicle crowding level. The present study documents new findings of the effect of crowding level on train ride time in the context of a developing country and suggests some important directions for future suburban train transport crowding valuation research. [Copyright &y& Elsevier]

Abstract: The Prototype Fast Breeder Reactor (PFBR) is currently under construction at Kalpakkam, India. PFBR has eight numbers of sodium heated once through Steam Generators (SG) each with 157 MWt capacity. Parts like steam generator tube sheet will see high temperature gradients during normal operation as well as in transient conditions. Thermal baffles are provided to protect the steam generator tub e sheets from the high temperature gradients during transient and steady state conditions. In Steam Generator Test Facility (SGTF) of IGCAR a 5.5MWt capacity SG was tested for its thermal hydraulic performance. Effectiveness of the thermal baffles provided in the model SG of PFBR is studied numerically and the performance of the same has been predicted. Further Transient experiments were conducted in Steam Generator Test Facility for evaluating the same. This paper brings out the details of numerical studies and the experimental evaluation of the effectiveness of thermal baffles provided to protect the steam generator tube sheets. [Copyright &y& Elsevier]

Abstract: Towards formulating guidelines for performance evaluation of buildings to site-specific earthquakes, studies are reported in literature on the effect of various critical parameters. No study is, however, reported on the effect of depth of soil stratum. In this paper, a methodology is proposed and applied for performance evaluation of buildings for site-specific earthquakes including depth of soil stratum as a parameter. The methodology integrates independent procedures meant for performance evaluation of buildings and site-specific seismic analysis. Application of the proposed methodology enables to determine performance point of a building in terms of inelastic displacement and base shear. Numerical application of the methodology is demonstrated using the particulars of Delhi region. Two typical RC buildings (B1 and B2) with significantly different inelastic behaviour, assumed to be located on soil depths ranging from 10 to 200m are chosen for the application study. Capacity spectra of the buildings are generated from nonlinear static analysis. Studies indicate that for building B1, with elasto-plastic behaviour, the depth of soil stratum strongly influences demand on inelastic displacement compared to that on inelastic base shear. For building B2, with continuously varying inelastic behaviour, the depth of soil stratum is observed to have significant influence on both the inelastic base shear as well as inelastic displacement. Responses of the buildings are compared with that obtained based on design spectrum of Indian seismic code. For both the cases, inelastic displacements as well as inelastic base shears are underestimated by Indian seismic code for certain depths of soil stratum. Proposed methodology enables the calculation of realistic values of inelastic base shear and corresponding displacement of a building for site-specific earthquakes by considering the actual characteristics of soil stratum. [Copyright &y& Elsevier]

This study quantifies the erosion of the Chennai coast in India and predicts how the shoreline will recede in the future. Previous studies in this region have reported erosion rates varying anywhere from 2 to 8 m/y. Such a high level of inconsistency in reported rates has hindered effective and sustainable coastal management. The research reported in this paper addresses this issue, using mapping data from 1904, 1974, 1996, and 2002 to estimate, by linear regression, the shoreline recession. The 10 km stretch of coast N of the fishing port at Chennai is repeatedly threatened during the NE monsoon, and as the process continues, the existence of a vital road link (the east-coast highway) is challenged by the fury of the waves. It is estimated that 260 ha of land has been lost between 1893 and 1955 and that 30 ha was destroyed by the sea between 1980 and 1989. Overall loss between 1893 and 1989 has been estimated in the order of 350 ha. The cost of land alone lost to the sea is in the order of US$40 million. The N Chennai coast has thus become volatile and is in need of immediate relief measures for the upkeep of the coastal region. Predictions for the next 250 years were then undertaken using a variety of techniques ranging from a process-based numerical model (Soft Cliff And Platform Erosion) to geometric approaches (including historical-trend analysis, the modified Bruun model, and Sunamura's shore platform model. The mean historic rate of erosion in the Chennai region is 1.11 m/y (60.15 m/y), significantly less than previously reported, though still very high. Subsequent predictions were used to identify a series of significant economic, ecological, and social features at risk, and to estimate when they will be lost to erosion if left unprotected. [ABSTRACT FROM AUTHOR]

According to the in situ measured data of the air temperature and ground temperature inside of Kunlun mountain tunnel on Qing–Tibet railway, China, the thawed extent of the permafrost surrounding the tunnel is very large, caused by the latent heat of the cast in situ concrete lining insulation during excavation in winter and other artificial activities. In this paper, taking the coupled effects of moisture transfer and heat conduction into account, a finite element formula of this problem is derived from the governing differential equations with phase change and moisture transfer equations using Galerkin''s solution. Using the computer program, predictions for the refreezing of Kunlun mountain permafrost tunnel are made. The analysis results show that the vault of Kunlun mountain tunnel would have been refrozen by 31 March 2004, the arch bottom by 30 September 2004 and the total tunnel by 30 September 2005, without insulation material. On the other hand, if the tunnel is fitted with insulation material, whose thermal conductivity is equal to 0.03 W/m.K and thickness of 0.05 m, the vault of Kunlun mountain tunnel would have been refrozen by 31 March 2004, the arch bottom by 31 December 2004, the left wall by 31 March 2006, and the right wall by 30 September 2006. Thus, insulation material will delay the refreezing of Kunlun mountain permafrost tunnel. The thawed extent of the permafrost surrounding the tunnel in cold regions caused by construction must be considered, and the time of the field observation should be extended, or observational results, such as their temperature and stress field, will greatly be different from results in stability. [Copyright &y& Elsevier]

• SHM experimental campaign conducted on a multi-arch masonry bridge located in India. • Large longitudinal crack on one of the arches detected with considerable crack width. • SHM monitored with crack growth monitoring and tilting of the spandrels. • Application of two different heavy loads (water tank and hydra crane) located in different positions. • Numerical modelling with advanced full 3D approach with adaptive NURBS FEM in limit analysis. The paper presents some SHM results belonging to a wide experimental campaign conducted on a multi-arch masonry bridge located near Mumbai (India), exhibiting a large longitudinal crack on one of the arches and the corresponding advanced numerical evaluations carried out with a NURBS kinematic limit analysis approach, used to assess the stability of the arch subjected to the passage of heavy traffic loads. The masonry bridge is a three-arch structure built during the mid-19th century by British engineers to connect Bombay with the inland of the Indian subcontinent. At present, it is characterized by a heavy state of degradation especially in one of the arches that requires an immediate evaluation of the safety under the passage of traffic loads and possible ideas of interventions to strengthen the structure, in order to avoid the propagation of deep cracks along the longitudinal direction. The adopted SHM includes the crack growth monitoring and tilting of the spandrels under the application of two different heavy loads (a water tank truck and a hydra crane) located in different positions of the arch. Numerical modelling is carried out with a full 3D approach with NURBS finite elements in limit analysis that takes into account the pre-existing crack opening and predicts with great accuracy the ultimate loads in different scenarios and the corresponding active failure mechanisms. From experimental monitoring and numerical simulations results, it is concluded that the bridge is still safe under the passage of traffic loads, but approaches the ultimate limit state for some specific configurations of the loads applied. A refurbishment is therefore needed to avoid any further propagation of the cracks up to collapse. [ABSTRACT FROM AUTHOR]

The highly populated north central India receives 90% of annual rainfall during June to September. The interannual variation of summer monsoon rainfall is less studied compared to central and western India, due to its weak signal with the El-Niño-Southern Oscillation (ENSO). Previous studies have reported a marked decadal variation in the ENSO influences on north India rainfall, but the teleconnections of this variation are not satisfactorily understood. A pathway of the changing ENSO influences on north central India rainfall is revealed from observational data analysis and numerical experiments. While La Niña-like conditions produce anomalous northeasterly wind over India and reduce the tropospheric wind shear, the emergence of the Atlantic Niño appears to overtake this ENSO influence. The Atlantic Niño intensifies the meridional stationary wave affecting pressure anomaly over northwest Europe. This excites the Eurasian Rossby wave train along the mid-latitude producing upper-troposphere high pressure anomaly, subsequently affecting north India. Future work should examine the extent to which these teleconnections are represented in climate forecast models to aid the seasonal prediction of north central India rainfall. [ABSTRACT FROM AUTHOR]

Ecballocystopsis (Oocystaceae, Chlorellales, Trebouxiophyceae) is a rare green algal genus, represented by only five taxa: E. dichotoma var. dichotoma from China and E. indica, E. desikacharyi, E. himalayensis and E. dichotoma var. minuta from India. Here we propose the novel variety E. dichotoma var. anandii from Jharkhand, synonymization of E. himalayensis with E. dichotoma and erection of E. dichotoma var. minuta to a separate species as E. minuta stat. et comb. nov. These taxonomic changes are well supported by the results of a multivariate analysis based on a numerical taxonomic approach. Cluster analysis (CA), principal component analysis (PCA) and principal coordinates analysis (PCoA) were performed to resolve the species delimitation ambiguity and supplement the morphology‐based classification of the genus. Ecballocystopsis himalayensis and E. dichotoma grouped in a single cluster along with the proposed new variety, while E. indica, E. desikacharyi and E. minuta formed separate clusters. An identification key to the species of the genus Ecballocystopsis is also presented. [ABSTRACT FROM AUTHOR]

A study on a devastating rainfall-induced landslide at Malin, India, which resulted in 160 deaths including the destruction of an entire village in July 2014 has been presented. The area was under a massive rainstorm which lasted for 3 days before the tragedy. The seepage into the slope due to the rainfall infiltration and the corresponding factor of safety of the slope at Malin has been quantified using a two-dimensional numerical model. The study indicates that the continuous rainfall infiltration develops a perched water table near the slope surface which results in the saturation and the positive pore water pressure build up at a shallow depth. With the increasing intensity and the rainfall duration, this depth of saturated zone increases rapidly. Though the Malin slope has an adequate factor of safety of 1.6, initially, but with continuous rainfall and increase in rainfall intensity, the factor of safety reduces to less than one on the day of tragedy. The parametric study indicates that the factor of safety of the Malin slope is adequate after 24 h of 2 mm/h, 5 mm/h and 10 mm/h of rainfall. But it drops rapidly to less than 1 after 7, 6, 6, 3, 2 and 1-h of 20 mm/h, 30 mm/h, 40 mm/h, 50 mm/h, 60 mm/h and 70 mm/h of rainfall, respectively. The slope, on which the Malin village is located, is initially safe but the debris from the upper portions of the slope moves downward destroying the residential area of the Malin village. [ABSTRACT FROM AUTHOR]

A prediction model based on the perfect prognosis method was developed to predict the probability of lightning and probable time of its occurrence over the south-east Indian region. In the perfect prognosis method, statistical relationships are established using past observed data. For real time applications, the predictors are derived from a numerical weather prediction model. In the present study, we have developed the statistical model based on Binary Logistic Regression technique. For developing the statistical model, 115 cases of lightning that occurred over the south-east Indian region during the period 2006-2009 were considered. The probability of lightning (yes or no) occurring during the 12-hour period 0900-2100 UTC over the region was considered as the predictand. The thermodynamic and dynamic variables derived from the NCEP Final Analysis were used as the predictors. A three-stage strategy based on Spearman Rank Correlation, Cumulative Probability Distribution and Principal Component Analysis was used to objectively select the model predictors from a pool of 61 potential predictors considered for the analysis. The final list of six predictors used in the model consists of the parameters representing atmospheric instability, total moisture content in the atmosphere, low level moisture convergence and lower tropospheric temperature advection. For the independent verifications, the probabilistic model was tested for 92 days during the months of May, June and August 2010. The six predictors were derived from the 24-h predictions using a high resolution Weather Research and Forecasting model initialized with 00 UTC conditions. During the independent period, the probabilistic model showed a probability of detection of 77% with a false alarm rate of 35%. The Brier Skill Score during the independent period was 0.233, suggesting that the prediction scheme is skillful in predicting the lightning probability over the south-east region with a reasonable accuracy. [ABSTRACT FROM AUTHOR]

In order to have an understanding of the coastal processes along the southwest coast of India (8u49 N, 77u 339 E to 8u139 N, 77u149 E), a data set available for the changes in beach width for a period of 5 years (1993-1998) over a length of about 50 km was categorized and analysed in relation to the seasons. Since the study area is densely populated and was also affected partially by the great Indian Ocean tsunami, a freshmeasurement campaign of beach profile changes up to a water depth of 6 m at four different locations along the coast was carried out. These measurements have been adopted to validate a finite difference-based numerical model that employs the empirical formulation of Larson and Kraus (1989) for the prediction of beach profile changes. We simulated the offshore wave climate from National Centre for Environmental Prediction wind data using the Wave AnalysisModel (WAM), whereas the nearshore wave climate was derived by adopting theMIKE21 ParabolicMild Slope module. Results compared well with each other. The prediction from the numerical model revealed that the average onshore-offshore transport varies from about 50 to 200 m3 y21m21 width of the beach. [ABSTRACT FROM AUTHOR]

The performance of the Advanced Regional Prediction System (ARPS) in simulating an extreme rainfall event is evaluated, and subsequently the physical mechanisms leading to its initiation and sustenance are explored. As a case study, the heavy precipitation event that led to 65 cm of rainfall accumulation in a span of around 6 h (1430 LT-2030 LT) over Santacruz (Mumbai, India), on 26 July, 2005, is selected. Three sets of numerical experiments have been conducted. The first set of experiments (EXP1) consisted of a four-member ensemble, and was carried out in an idealized mode with a model grid spacing of 1 km. In spite of the idealized framework, signatures of heavy rainfall were seen in two of the ensemble members. The second set (EXP2) consisted of a five-member ensemble, with a four-level one-way nested integration and grid spacing of 54, 18, 6 and 1 km. The model was able to simulate a realistic spatial structure with the 54, 18, and 6 km grids; however, with the 1 km grid, the simulations were dominated by the prescribed boundary conditions. The third and final set of experiments (EXP3) consisted of a five-member ensemble, with a four-level one-way nesting and grid spacing of 54, 18, 6, and 2 km. The Scaled Lagged Average Forecasting (SLAF) methodology was employed to construct the ensemble members. The model simulations in this case were closer to observations, as compared to EXP2. Specifically, among all experiments, the timing of maximum rainfall, the abrupt increase in rainfall intensities, which was a major feature of this event, and the rainfall intensities simulated in EXP3 (at 6 km resolution) were closest to observations. Analysis of the physical mechanisms causing the initiation and sustenance of the event reveals some interesting aspects. Deep convection was found to be initiated by mid-tropospheric convergence that extended to lower levels during the later stage. In addition, there was a high negative vertical gradient of equivalent potential temperature suggesting strong atmospheric instability prior to and during the occurrence of the event. Finally, the presence of a conducive vertical wind shear in the lower and mid-troposphere is thought to be one of the major factors influencing the longevity of the event. [ABSTRACT FROM AUTHOR]

The study illustrates the utility of STREAM II as a modeling package to determine the pollution load due to organic matter in the River Yamuna during its course through the National Capital Territory that is Delhi, India. The study was done for a period from 1995–2005. Model simulates the dissolved oxygen and biochemical oxygen demand parameters in a two-dimensional fashion by performing the numerical solution to a set of differential equations representing aquatic life with the help of Crank–Nicholson finite difference method. The model was simulated and calibrated through the field water-quality primary data and the secondary data which were taken from Central Pollution Control Board. The main reasons for the high river pollution is increasing population of Delhi and other states, leading to generation of huge amounts of domestic sewage into the river Yamuna. The model gave a good agreement between calibrated and observed data, thus, actualizing the validity of the model. However, discrepancies noticed during model calibrations were attributed to the assumptions adopted in the model formulation and to lack of field data. [ABSTRACT FROM AUTHOR]

The onset of the Indian summer monsoon (ISM) over the southern tip of the Indian peninsula [also known as monsoon onset over Kerala (MOK)] has been considered the beginning of India’s rainy season. The Indian Meteorological Department (IMD) makes an official prediction of ISM onset every year using a subjective method. Based on an analysis of the past 60-yr (1948–2007) record, the authors show that the onset date can be objectively determined by the beginning of the sustained 850-hPa zonal wind averaged over the southern Arabian Sea (SAS) from 5° to 15°N, and from 40° to 80°E. The rapid establishment of a steady SAS westerly is in excellent agreement with the abrupt commencement of the rainy season over the southern tip of the Indian peninsula. In 90% of the years analyzed, this simple and objective index has excellent agreement with the onset dates that are subjectively defined by the IMD. There are only 3 yr of the past 60 yr during which the two onset dates differ by more than 10 days, and none of them perfectly reflects the MOK. A prominent onset precursor on the biweekly time scale is the westward extension of the convection center from the equatorial eastern Indian Ocean toward the southeast Arabian Sea. On the intraseasonal time scale, the onset tends to be led by northeastward propagation of an intraseasonal convective anomaly from the western equatorial Indian Ocean. The objective determination of the onset based on the SAS low-level westerly is a characteristic representation of the complex process of the ISM onset. Given its objectiveness and its representation of the large-scale circulation, the proposed new onset definition provides a useful metric for verifying numerical model performance in simulating and predicting the ISM onset and for studying predictability of interannual variations of the onset. [ABSTRACT FROM AUTHOR]

The article discusses a study on the two-dimensional (2-D) physically based finite element runoff numerical model for small agricultural watersheds, known as ROMO2D, applied to Shiwalik foothills in Northern India. It focuses on the development of the watershed hydrology model, which is designed to simulate erosion from small agricultural watersheds on an event basis, as well as notes its components. It offers information on the ROMO2D computer program. Various flow-governing equations are also presented.

Fluoride-contaminated drinking water is a serious public health hazard in some parts of India. Field surveys have been conducted in fluoride-affected areas of the Birbhum district, West Bengal, India. From these surveys, it is found that in certain locations the drinking water contains less fluoride (within the permissible limit1) than in adjoining areas. We have isolated a strain of Streptococcus species from these wells that has the ability to remove the fluoride ion from the water. We have grown the bacteria in different concentrations of fluoride and monitored the decline in the free fluoride ion concentration. A simplified model of fluoride and bacterial dynamics is proposed. The model is handled both analytically and numerically. For numerical solution mainly our own laboratory data are used. Calibration and validation are performed with different sets of experimental data. Analytical solutions show that the bacterial consumption and growth rates are the most important parameters in the system. Analysis shows asymptotic stability of the system. [ABSTRACT FROM AUTHOR]

Rational methods for setting priorities for maintenance of irrigation systems are developed. The methods, which are aimed for use by irrigation system managers, describe the link between maintenance activities and the consequent improvement in the performance of an irrigation system. Hydraulic analysis methods are developed for assessing potential `restorative maintenance' tasks, which are usually undertaken to increase the deliveries of water to the outlets. The new methods use inputs that have been limited to those easily available from scheme records, the knowledge of irrigation agency staff and from infrastructure inspections. Two alternative methods are developed, one based on Fuzzy Logic and one on numerical modelling. Risk analysis methods are also developed for assessing `preventative maintenance', to reduce the probability of supply failures. Benefit-cost ratios are derived that allow direct comparison between maintenance tasks of each type. The methods are tested at two irrigation systems in Tamil Nadu, India. [ABSTRACT FROM AUTHOR]