Use of Geospatial Tools to Prioritize Zones of Hydro-Energy Potential in Glaciated Himalayan Terrain     

Lydia Sam  Anshuman Bhardwaj  Vinay S P Sinha  Pawan K Joshi  Rajesh Kumar 《Journal of the Indian Society of Remote Sensing》2016,44(3):409-420

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Magnetite nanoparticles coated sand for arsenic removal from drinking water     

Sarita Kango  Rajesh Kumar 《Environmental Earth Sciences》2016,75(5):381

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Report on International Conference on Maritime Archaeology with Special Reference to Indian Ocean countries & 10th Biannual Conference of Society for Marine Archaeology,NIO, Goa     

Sandhya Misra  S.V. Rajesh  G.S. Abhyan 《Journal of the Geological Society of India》2018,91(6):754-754

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Analysis of Hydraulic Conductivity Averaging Schemes for One-Dimensional, Steady-State Unsaturated Flow     

Rajesh Srivastava  Amado Guzman-Guzman 《Ground water》1995,33(6):946-952

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Sea navigation, challenges and potentials in South East Asia: an assessment of suitable sites for a shipping canal in the South Thai Isthmus     

Rajesh B. Thapa  Michiro Kusanagi  Akira Kitazumi  Yuji Murayama 《GeoJournal》2007,70(2-3):161-172

This paper discusses the situation of sea navigation in south East Asia focusing on the Strait of Malacca. The strait links the Indian and Pacific oceans, which is considered one of the busiest in several narrow channels around the world. The paper highlights the significance of the strait to global maritime trade, volume of traffic, and rising environmental and social consequences in the strait. A feasibility study of constructing a new shipping canal in the South Thai Kra Isthmus as an alternative option of Malacca route had been studied since 19th century. The paper explores suitable sites for a potential shipping canal in the Kra Isthmus using physiographic spatial data i.e., elevation, sea charts, geology, soils and river systems. Each spatial data was considered as a separate decision variable for site evaluation. Separate evaluation criterions were prepared for each variable based on shipping canal requirements. Overlaying the maps in GIS environment, the variables were carefully evaluated, and five geographic sites for the canal were derived. The length of the shipping canal over sea and land was computed for each site. Site B located in south of Ranong and Chumphon provinces, was the shortest one, whereas site C in Surat Thani, Pangnna and Krabi provinces was the longest. However, each site consisted of benefits and constraints.  相似文献   

Improved seismic hazard model with application to probabilistic seismic demand analysis     

Brendon A. Bradley  Rajesh P. Dhakal  Misko Cubrinovski  John B. Mander  Greg A. MacRae 《地震工程与结构动力学》2007,36(14):2211-2225

An improved seismic hazard model for use in performance‐based earthquake engineering is presented. The model is an improved approximation from the so‐called ‘power law’ model, which is linear in log–log space. The mathematics of the model and uncertainty incorporation is briefly discussed. Various means of fitting the approximation to hazard data derived from probabilistic seismic hazard analysis are discussed, including the limitations of the model. Based on these ‘exact’ hazard data for major centres in New Zealand, the parameters for the proposed model are calibrated. To illustrate the significance of the proposed model, a performance‐based assessment is conducted on a typical bridge, via probabilistic seismic demand analysis. The new hazard model is compared to the current power law relationship to illustrate its effects on the risk assessment. The propagation of epistemic uncertainty in the seismic hazard is also considered. To allow further use of the model in conceptual calculations, a semi‐analytical method is proposed to calculate the demand hazard in closed form. For the case study shown, the resulting semi‐analytical closed form solution is shown to be significantly more accurate than the analytical closed‐form solution using the power law hazard model, capturing the ‘exact’ numerical integration solution to within 7% accuracy over the entire range of exceedance rate. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Temporal Assessment of Growing Stock, Biomass and Carbon Stock of Indian Forests   总被引：1，自引：0，他引：1  

R. K. Manhas  J. D. S. Negi  Rajesh Kumar  P. S. Chauhan 《Climatic change》2006,74(1-3):191-221

The dynamics of terrestrial ecosystems depends on interactions between carbon, nutrient and hydrological cycles. Terrestrial ecosystems retain carbon in live biomass (aboveground and belowground), decomposing organic matter, and soil. Carbon is exchanged naturally between these systems and the atmosphere through photosynthesis, respiration, decomposition, and combustion. Human activities change carbon stock in these pools and exchanges between them and the atmosphere through land-use, land-use change, and forestry.In the present study we estimated the wood (stem) biomass, growing stock (GS) and carbon stock of Indian forests for 1984 and 1994. The forest area, wood biomass, GS, and carbon stock were 63.86 Mha, 4327.99 Mm³, 2398.19 Mt and 1085.06 Mt respectively in 1984 and with the reduction in forest area, 63.34 Mha, in 1994, wood biomass (2395.12 Mt) and carbon stock (1083.69 Mt) also reduced subsequently. The Conifers, of temperate region, stocked maximum carbon in their woods, 28.88 to 65.21 t C ha⁻¹, followed by Mangrove forests, 28.24 t C ha⁻¹, Dipterocarp forests, 28.00 t C ha⁻¹, and Shorea robusta forests, 24.07 t C ha⁻¹. Boswellia serrata, with 0.22 Mha forest area, stocked only 3.91 t C ha⁻¹. To have an idea of rate of carbon loss the negative changes (loss of forest area) in forest area occurred during 1984–1994 (10yrs) and 1991–1994 (4yrs) were also estimated. In India, land-use changes and fuelwood requirements are the main cause of negative change. Total 24.75 Mt C was lost during 1984–1994 and 21.35 Mt C during 1991–94 at a rate of 2.48 Mt C yr⁻¹ and 5.35 Mt C yr⁻¹ respectively. While in other parts of India negative change is due to multiple reasons like fuelwood, extraction of non-wood forest products (NWFPs), illicit felling etc., but in the northeastern region of the country shifting cultivation is the only reason for deforestation. Decrease in forest area due to shifting cultivation accounts for 23.0% of the total deforestation in India, with an annual loss of 0.93 Mt C yr⁻¹.  相似文献   

Petrology, geochemistry and tectonic significance of Palaeoproterozoic alkaline lamprophyres from the Jungel Valley, Mahakoshal supracrustal belt, Central India     

Rajesh K. Srivastava  N. V. Chalapathi Rao 《Mineralogy and Petrology》2007,89(3-4):189-215

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International Symposium on Geology and Mineral Resources of Madagascar     

H.M. Rajesh 《Gondwana Research》1998,1(3-4):425-427

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System identification for nonlinear maneuvering of large tankers using artificial neural network     

G. Rajesh  S.K. Bhattacharyya   《Applied Ocean Research》2008,30(4):256-263

This paper deals with the application of nonparametric system identification to a nonlinear maneuvering model for large tankers using artificial neural network method. The three coupled maneuvering equations in this model for large tankers contain linear and nonlinear terms and instead of attempting to determine the parameters (i.e. hydrodynamic derivatives) associated with nonlinear terms, all nonlinear terms are clubbed together to form one unknown time function per equation which are sought to be represented by the neural network coefficients. The time series used in training the network are obtained from simulated data of zigzag maneuvers and the proposed method has been applied to these data. The neural network scheme adopted in this work has one middle or hidden layer of neurons and it employs the Levenberg–Marquardt algorithm. Using the best choices for the number of hidden layer neurons, length of training data, convergence tolerance etc., the performance of the proposed neural network model has been investigated and conclusions drawn.  相似文献