Hydrogeomorphological studies by remote sensing application in niva river basin, chittoor district, andhra pradesh

To evaluate the hydrogeomorphological conditions of Niva river basin Chittoor district, Andhra Pradesh, geological, hydrogeological and geomorphological studies were carried out. through visual interpretation of Landsat 5, FCC with adequate ground truth. The study shows that the Niva river basin is occupied by granites and gneisses of Archaean age with intrusive bodies of dolerites. The recent alluvium deposits are present along the stream courses. The study area is traversed by various directional fractures/lineaments and most of them are NESW, ENE-WSW and EW directions. Groundwater potential of geomorphological units viz. Denudational hill, Residual hill, Pediment, Pediplain and Valley fill is discussed.     

Spatial pattern analysis of fire events in Central India – A case study

The impact of fires on environment can have adverse effects. To fully understand the synoptic behaviour of fire events, information on the spatial distributions and their pattern are highly important. In this study, we used 9-year (1997–2005) integrated fire count datasets derived from Along Track Scanning Radiometer (ATSR) satellite to geographically map the distribution of fire events in the Madhya Pradesh state, central India. We then used robust spatial metrics to test the spatial pattern of fire events against the hypothesis of complete spatial randomness (CSR). Specifically, we used the index of dispersion, Green's index, in addition to nearest neighbour statistic for testing CSR. Also, quantification of clustering is carried out using Ripley's K-function. To spatially map the fire events, we used Kernel density estimation that relies on bi-variate probability density functions. Results from using different spatial pattern metrics and nearest neighbour statistics suggested relatively high clustering of fire events in the study area. In addition, results from Ripley's K-function suggested the fire events to be clustered at a lag-distance of ～60 mile radius. By converting original fire ignition locations that are based on historical records to continuous density surfaces, the probability of fire events could be mapped effectively using kernel density estimation. As each fire event is the result of certain spatial process including biophysical and anthropogenic attributes, results from this study can provide useful information on fire management at a local district level. Also, the analysis presented in this study illustrates how spatial patterns in the point datasets can be quantified using different dispersion indices, clustering and density estimation techniques.     

Regional tourism and South-South economic cooperation

Regional tourism within developing countries is a growing phenomenon. Yet this aspect has been largely neglected in social science research as well as tourism planning. This paper highlights the general nature, scale and economic significance of regional tourism in three leading regions in Asia, Africa and Latin America. The topic is especially timely as economic self-reliance and cooperation are increasingly reiterated in the context of the emergence of regional groupings. A key question addressed is whether regional tourism development represents any new and viable prospects for regional economic improvement and partnership, especially compared to international tourism centred on attracting visitors from industrialized countries. Based on a critical assessment of the experiences of three regional blocs (ASEAN – the Association of South-East Asian Nations; SADC – the Southern African Development Community; and Mercosur – a common market comprising Argentina, Brazil, Paraguay and Uruguay, with Chile being an associated member), the paper suggests that a basic appreciation of the prospects of regional tourism is not enough to produce perceptible benefits. Regional tourism development is occurring in a haphazard manner, with little attention to managing existing socio-economic inequalities and centre-periphery relations. The paper is based primarily on the review of secondary literature readily available to the author combined with a few documents obtained directly from different regional organizations or through Internet search. A small amount of material, especially concerning emerging tourism trends and outcomes, is drawn from a research project on national mass tourism in developing countries coordinated by the author at the United Nations Research Institute for Social Development, Geneva.     

Reconstructing missing hourly real-time precipitation data using a novel intermittent sliding window period technique for automatic weather station data

Precipitation is the most discontinuous atmospheric parameter because of its temporal and spatial variability. Precipitation observations at automatic weather stations (AWSs) show different patterns over different time periods. This paper aims to reconstruct missing data by finding the time periods when precipitation patterns are similar, with a method called the intermittent sliding window period (ISWP) technique—a novel approach to reconstructing the majority of non-continuous missing real-time precipitation data. The ISWP technique is applied to a 1-yr precipitation dataset (January 2015 to January 2016), with a temporal resolution of 1 h, collected at 11 AWSs run by the Indian Meteorological Department in the capital region of Delhi. The acquired dataset has missing precipitation data amounting to 13.66%, of which 90.6% are reconstructed successfully. Furthermore, some traditional estimation algorithms are applied to the reconstructed dataset to estimate the remaining missing values on an hourly basis. The results show that the interpolation of the reconstructed dataset using the ISWP technique exhibits high quality compared with interpolation of the raw dataset. By adopting the ISWP technique, the root-mean-square errors (RMSEs) in the estimation of missing rainfall data—based on the arithmetic mean, multiple linear regression, linear regression, and moving average methods—are reduced by 4.2%, 55.47%, 19.44%, and 9.64%, respectively. However, adopting the ISWP technique with the inverse distance weighted method increases the RMSE by 0.07%, due to the fact that the reconstructed data add a more diverse relation to its neighboring AWSs.     

Physical and chemical response of zircons to deformation

An investigation of U-Pb isotopic systematics in zircons from mylonitized Henderson Gneiss (Sinha and Glover 1978) revealed that selected zircon fractions from the mylonite zone suffered total loss of radiogenic Pb at 460 m.y. To further investigate the relationship between Pb loss, U gain, and grain size reduction associated with increasing strain in the shear zone, we have characterized the chemistry and morphology of zircons in the mylonitic rocks, using both electron microprobe analysis and scanning electron microscopy.SEM photographs of the zircons indicate that strain-correlated fracturing and size reduction of the zircons accompanied Pb loss throughout the mylonite zone. Stresses imposed by the expansion of initially U-rich, -damaged portions of the crystal resulted in microfracturing of the more brittle crystalline material proximal to the U-rich zones. During mylonitization, fractures propagated preferentially along these zones allowing metamorphic fluids to penetrate the easily-leached, -damaged portions of the zircons. Removal of 75% of the radiogenic Pb from zircons in the least-deformed zone of the mylonites may have occurred via this mechanism.Irregular, porous zircon overgrowths are also evident from the SEM photographs. Overgrowths are strongly enriched in U, Y and P with respect to the relict, Henderson Gneiss-derived cores, and tend to increase in volume from the protomylonite to the blastomylonite. Thus, the development of overgrowths on the zircons accounts for the U gain observed by Sinha and Glover (1978), and indicates that the transport of high field strength cations (e.g., Zr⁴⁺, Hf⁴⁺, U⁴⁺, etc.) occurred during prograde mylonitization at 460 m.y.A retrograde shearing event at 273 m.y. caused no further disturbance in the U-Pb isotopic systematics of the zircons. Pb retention by zircons during the later episode may have been the result of 1) the participation of H₂O-rich, relatively noncorrosive fluids and/or 2) the lack of further fracturing and size reduction in a strain gradient of lower magnitude than the prograde event.     

Gravitational instability of a rotating partially-ionized plasma carrying a uniform magnetic field with hall effect

The problem of gravitational instability of an infinite homogeneous self-gravitating medium carrying a uniform magnetic field in the presence of Hall effect has been investigated to include the effect due to rotation. The dispersion relation has been obtained. It has been found that the Jeans's criterion for the instability remains unaffected even when the effect due to rotation is considered in the presence of Hall effect carrying a uniform magnetic.     

Numerical simulation of cloud burst event on August 05, 2010, over Leh using WRF mesoscale model

Localized deep cumulus convective clouds have a capability of giving enormous amount of rainfall over a limited horizontal area, within a short span of time. Such types of extreme rainfall events are most common over the high elevated areas of Northern India during the Southwest monsoon season which causes widespread damage to the property and lives. Therefore, it is necessary to predict such extreme events accurately to avoid damage associated with them. The numerical mesoscale model Weather Research and Forecasting has been used to simulate the cloud burst event of Leh on August 05, 2010, so as to capture the main characteristics of the various parameters associated with this localized mesoscale phenomenon. The model has been integrated with four nested domains keeping Leh and its adjoining area as center. Two cloud microphysics parameterization schemes namely WSM3 and WSM6 have been used for the sensitivity experiments and results have been analyzed to examine the performance of both the schemes in capturing such extreme localized heavy rainfall events. Results show that the WSM6 microphysics was able to simulate the precipitation near to the observation. WSM3 microphysics simulated the location of the circulation near to the observation. In addition, the results also show that the maximum magnitudes of meridional and vertical wind as simulated with WSM3 microphysics are 12 and 4 m/s, respectively.