Remote sensing and GIS application for land quality assessment for coffee growing areas of Karnataka

An assessment of land quality was carried out for coffee-growing areas of Karnataka using satellite image, toposheets and soil studies. The investigation focused on monitoring soil processes that control the land quality using satellite data in order to identify the land qualities that are ideal for coffee-growing; to identify the status of land qualities of coffee-growing areas using satellite imageries, toposheets and soil resource maps and to characterise land quality using soil studies in selected areas. The land quality was characterised using climatic data, terrain analysis and soil attributes. From the study it was observed that coffee growing lands of Gabbugal and Kelagur have best land qualities and coffee-growing areas of Balur and Nellikkad have moderate land qualities. Satellite image and aerial photographs were successfully used for monitoring the land quality and its changes in these areas. For optimum utilization of available natural resources on a sustainable basis, timely and reliable information on soils regarding their nature, extent and spatial distribution along with their potential and limitations is very important. The efficiency and accuracy of data are improved when remote sensing data products such as aerial photographs and satellite image are used.     

Inelastic seismic response of one-storey,asymmetric-plan systems: Effects of system parameters and yielding

The inelastic response of one-storey, asymmetric-plan systems to two excitations is presented and analysed with the objective of identifying the influence of system parameters: uncoupled lateral vibration period, uncoupled torsional-to-lateral frequency ratio, stiffness eccentricity, relative values of the strength and stiffness eccentricities, and yield factor. Furthermore, the influence of yielding on the response of asymmetric-plan systems is examined. In particular, we determine whether the well known relationship between the response of yielding and elastic single-degree-of-freedom (SDF) systems is also applicable to asymmetric-plan systems.     

Linking a prolonged Neo‐Tethyan magmatic arc in South Asia: Zircon U‐Pb and Hf isotopic constraints from the Lohit Batholith,NE India

The Neo‐Tethyan subduction that operated before the India‐Asia collision resulted in an Andean‐type convergent margin in South Asia and was associated with extensive arc magmatism that formed the Transhimalayan batholiths. Magmatism in the Gangdese Batholith, the largest batholith exposed in the Lhasa terrane of southern Tibet, is considered to have lasted from the early Jurassic to Eocene. However, eastward correlation of the Gangdese Batholith is uncertain because it is truncated by the eastern Himalayan syntaxis. Here, we report new data from the Lohit Batholith, NE India, including: (i) zircon U‐Pb ages of five granitoids from ca. 148 to 96 Ma; and (ii) zircon Hf isotopes of these rocks that yield high and positive ε_Hf(T) values. We argue that the Lohit Batholith is the eastward extension of the Gangdese Batholith, and can be correlated southward to the Wuntho‐Popa arc in West Burma, thus linking a prolonged Neo‐Tethyan magmatic arc system from southern Tibet to Southeast Asia.     

Indian summer monsoon during the last two millennia

The monsoon is a large‐scale feature of the tropical atmospheric circulation, affecting people and economies in the world's most densely populated regions. Future trends due to natural variability and human‐induced climate changes are uncertain. Palaeoclimate records can improve our understanding of monsoon dynamics and thereby reduce this uncertainty. Palaeoclimate records have revealed a dramatic decrease in the Asian summer monsoon since the early Holocene maximum 9 ka BP. Here we focus on the last 2 ka, where some records indicate an increasing trend in the summer monsoon. Analysing Globigerina bulloides upwelling records from the Arabian Sea, we find the weakest monsoon occurred 1500 a BP, with an increasing trend towards the present. Copyright © 2010 John Wiley & Sons, Ltd.     

Study of Cosmic-Ray Intensity Variations Associated with Anomalous,Long-Duration High-Speed Solar Wind Streams in 2003

High-speed solar wind streams (HSWS) were identified for solar cycles 22 and 23 (up to 2004). Preliminarily, HSWS were classified in three groups according to their continuous period of occurrence. In the declining phase of solar cycle 23, 2003 is found to be anomalous, showing a very large number of HSWS events of long duration (> ten days). We have studied the effect of HSWS on the cosmic-ray intensity as well as their relationship with geomagnetic disturbance index Ap on yearly, daily, and hourly bases. The yearly average of solar-wind speed was also found to be maximum in 2003. Being within the declining phase of solar activity, the occurrence of solar flares in 2003 is quite low. In particular during HSWS, no solar flares have been observed. Associations with cosmic-ray changes do not support the notion that the HSWS are usually effective in producing significant cosmic-ray decreases. Out of 12 HSWS events observed during the period 2002 (December) to 2003, four events of significant cosmic-ray decreases at all the stations have been selected for further analysis. The cosmic-ray intensity has been found to decrease during the first phase of the event (first five days of HSWS) at all three neutron-monitor stations situated at different latitudes with different cutoff rigidities. The rigidity spectra of observed decreases in cosmic-ray intensity for these four cases have been found to be significantly different than that of Fds (Forbush decrease). In two cases the spectra are softer, whereas in the other two they are harder than that of Fds. However, if the average of all four events is considered together then the spectra of the decrease in cosmic rays during HSWS exactly match that of Fds. Such a result implies that initially individual events should be considered, instead of combining them together, as was done earlier. The Ap index is also found to generally increase in the first phase of the event. However, the four events selected on the basis of cosmic-ray decrease are not always associated with enhanced values of the Ap index. As such, the significance of our study is that further detailed investigations for much longer periods and on an event-by-event basis is required to understand the effect of coronal-hole-associated HSWS.     

A new class of Inhomogeneous string cosmological models in general relativity

A new class of solutions of Einstein field equations has been investigated for inhomogeneous cylindrically symmetric space-time with string source. To get the deterministic solution, it has been assumed that the expansion (θ) in the model is proportional to the eigen value σ ¹  ₁ of the shear tensor σ ⁱ    _j . Certain physical and geometric properties of the models are also discussed.     

Earthquake analysis of gravity dams including hydrodynamic interaction

A general procedure for analysis of the response of gravity dams, including hydrodynamic interaction and compressibility of water, to the transverse horizontal and vertical components of earthquake ground motion is presented. The problem is reduced to one in two dimensions considering the transverse vibration of a monolith of a dam, and the material behaviour is assumed to be linearly elastic The complete system is considered as composed of two substructures—the dam, represented as a finite element system, and the reservoir, as a continuum of infinite length in the upstream direction governed by the wave equation. The structural displacements of the dam (including effects of water) are expressed as a linear combination of the modes of vibration of the dam with the reservoir empty. The effectiveness of this analytical formulation lies in its being able to produce excellent results by considering only the first few modes. The complex frequency response for the modal displacements are obtained first. The responses to arbitrary ground motion are subsequently obtained with the aid of the Fast Fourier Transform algorithm An example analysis is presented to illustrate results obtained from this method. It is concluded that the method is very effective and efficient and is capable of producing results to any desired degree of accuracy by including the necessary number of modes of vibration of the dam.     

Accidental torsion in buildings due to stiffness uncertainty

Discrepancies between the computed and actual values of the structural element stiffness imply that a building with nominally symmetric plan is actually asymmetric to some unknown degree and will undergo torsional vibration when subjected to purely translational ground motion. Such accidental torsion leads to increase in structural element deformations which is shown to be essentially insensitive to the uncoupled lateral vibration period of the system but is affected strongly by the ratio of uncoupled lateral and torsional vibration periods. The structural deformations increase, in the mean, by at most 10 and 5 per cent for R/C and steel buildings, respectively, and by much smaller amounts for a wide range of system parameters. The increase in structural deformations due to stiffness uncertainty is shown to be much smaller than implied by the accidental torsional provisions in the Uniform Building Code and most other building codes.