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11.
M. Tripti G. P. Gurumurthy L. Lambs J. Riotte K. Balakrishna 《Journal of the Geological Society of India》2018,92(5):579-587
The Western Ghats form a major mountain belt, next to the Himalayas, in controlling the flux of water and carbon to the northern Indian Ocean. This study attempts to understand the water and carbon cycles in two humid tropical river basins with its streams originating at higher altitudes of the Western Ghats, India. Water and suspended particulate matter (SPM) were collected on a monthly scale during summer monsoon season (June-September) from Swarna and Nethravati rivers draining into the Arabian Sea. For the source apportionment, samples have been measured for stable isotopes of oxygen (δ18O) and hydrogen (δ2H) in water and stable isotopes of carbon (δ13CPOC) in particulate organic matter (POM) at spatial scale from tributaries and main channel of rivers, and runoff water from agricultural land (dominant paddy field) and forest in the downstream region. The association between δ18O and deuterium-excess in river water and rain water shows that water in these tropical basins depicts rainout effect of marine source moisture during the onset of summer monsoon. As the monsoon intensifies, the fresher rain water replenishes older water stored previously in sub surface soil layer leading to its flushing into the river during summer monsoon season. Stable carbon isotope ratio and elemental ratio of POM (δ13CPOC = -27.1 ± 0.4 ‰ and C/N = 8.1 ± 1.7) in two humid tropical river water during summer monsoon season is an admixture of suspended particulates from runoff water of forest (δ13CPOC = - 27.82 ± 0.4 ‰) and agricultural land (δ13CPOC = -26.29 ± 0.4 ‰). It is found that δ13CPOC shows minimal variability with SPM content and C/N ratio within the same organic carbon pool. The study emphasizes the need to consider the agricultural runoff contribution to the rivers while establishing the global elemental budget and observing the global climate change. 相似文献
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K. S. Guruge P. Goswami I. Watanabe S. Abeykoon V. P. Prabhasankar K. R. Binu D. I. Joshua K. Balakrishna M. Akiba N. Munuswamy 《International Journal of Environmental Science and Technology》2017,14(1):1-18
The concentrations of 27 major and trace elements are determined in surface water samples collected from 48 sites of diverse waterways in four states (Tamil Nadu, Kerala, Karnataka, and Telangana) of South India. The aims of this study are to identify the element distribution, comparatively assess the pollution risk, and evaluate human health risks related to diverse waterways in the study area. The results indicate that elements such as Cr, Se, As, Fe, and Mn are the major pollutants, as their concentrations exceeded the acceptable national and international water quality standards in several sites of Ennore, Adyar, Cooum, Periyar, and Vrishabhavathi rivers. Furthermore, statistical analysis reveals that the Ennore, Adyar, Cooum, Periyar, and Kaveri river basins are affected by various anthropogenic activities, leading to moderate-to-high pollution by As, Cr, Mn, Fe, and Se. Potential pollution sources are industrial waste, sewage intrusion, paint industry waste, and automobile runoff. Overall, the investigated sites are categorized into three major groups: highly, moderately, and least polluted. Risk on human health by metals is then evaluated using hazard quotients (HQs) and carcinogenic risk evaluation; the results indicated that As with HQ >1 is the most hazardous pollutant, which could lead to non-carcinogenic and carcinogenic concerns, particularly in children. This study helps in establishing pollutant loading reduction goal and the total maximum daily loads and consequently contributes to preserving public health and developing water conservation strategies. 相似文献
13.
B. K. Ranganath N. Pradeep V. B. Manjula Balakrishna Gowda M. D. Rajanna Damodar Shettigar P. P. Nageswara RAo 《Journal of the Indian Society of Remote Sensing》2004,32(1):49-58
The study evaluates the potential of satellite remote sensing technology for detection, mapping and monitoring of diseased
rubber plantation affected by Corynespora and Gloeosporium fungi, which causes leaf spot and leaf fall. Multi-date satellite
data of IRS-1C have been analyzed adopting enhancement and classification techniques to identify and extract information on
the spatial extent and distribution of healthy and diseased rubber plants with an accuracy of 90%. The diseased rubber plantations
have shown considerable reduction in the near-infrared reflectance followed by a rise in the reflectance in red and short
wave infrared. Vegetation index images generated for different periods have shown the progress of disease incidence, severity
and recovery of rubber plantations after fungicidal spraying. The study has demonstrated the use of remote sensing technology
in identifying and delineating diseased rubber plantations. Early detection of the disease would be of immense value for taking
up necessary control measures and minimize the loss. 相似文献
14.
Nisha Baby Krishnan Balakrishna Keshava Udayashankar Harikripa Narayana Manjunatha Busnur Rachotappa 《Aquatic Geochemistry》2021,27(3):173-206
Aquatic Geochemistry - Studies done on small tropical west-flowing river catchments located in the Western Ghats in southwestern India have suggested very intense chemical weathering rates and... 相似文献
15.
S. Balakrishna 《Bulletin of Volcanology》1963,26(1):273-296
Volcanic rocks occupy considerable regions in the western portion of India, attaining a maximum thickness of 7000′ near Igatpuri. These rocks are essentially basaltic in nature and are generally referred to as plateau basalts. An attempt has been made in this paper to present some results of geological and geophysical investigations carried out in the Deccan Traps. Three areas (Ajanta - Long. 75″41′ -75° 45′ E, Lat. 20° 32′ - 20° 35′ 15″ N, 18 sq. miles in area; Ellora -Long. 75″ 11′ - 75° 16′ E, Lat. 20° 1′ - 20° 9′ N, 80 sq. miles in area; and Chincholi - Long. 77° 22′ - 77° 30′ E, Lat. 17° 22′ -17° 30′ N, 50 sq. miles in area) have been chosen for this study because of their geological setting. A large number of field specimens have been collected for petrographic study. This is supplemented by examination of microsections and chemical analyses of a few traps. In the Chincholi area where the trap overlies the granites, limestones seem to intervene in between trap and granites. With a view to estimate the possible thickness of the limestone beds, the distribution of intensity of magnetic field in a portion of the area has been studied with a magnetometer. Magnetic susceptibilities in case of few specimens have also been studied. Elastic constants of Deccan Traps have been determined for fifty specimens, employing the Wedge Method. These are further correlated with textural features and porosity values. Such an integrated geological and geophysical investigation on Deccan Traps is bound to reveal some interesting results. 相似文献
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17.
Gulam Rasool Bhat S. Balaji Bikram S. Bali Vazeem Iqbal Balakrishna Hamid Hussain 《Journal of the Geological Society of India》2018,91(1):81-90
A comprehensive paleoseismological investigations was carried out along Joggers Park Fault (striking NW-SE) reveals pervasive traces of active compressional tectonics (blind thrusting) and shallow-surface recent tectonic signatures along the fault. The geometry and trends in the tectonic deformation of the blind zone (shallow-subsurface stratigraphy) were examined with GPR and electrical resistivity tomography (ERT) and vertical electrical sounding (VES), strongly demonstrates severe tectonic deformation (persistent tectonic style) from Quaternary to Holocene times in a compressive stress regime. The surface manifestation of deformation (topographic expression) along the fault can be marked as hanging wall uplift and can be visually observed in the exposed sections at nearly half kilometer distance from the table land of Joggers Park in the form of a well-defined disconnected high angle thrust fault scarp (reverse fault). The reverse fault kinematically and intimately linked with underlying fault geometry provides adduced evidence to evaluate strike displacement profiles (displacement length relationship) along the fault. In addition, deformed stacked colluvial wedge below the scarp represents a powerful basis to calibrate recent and long term slip rates of the underlying fault. 相似文献
18.
Balakrishna S. Balaji Shrikant Maury G. Narshimulu 《Journal of the Geological Society of India》2014,83(4):393-402
Ground water occurs in weathered formations of unsaturated zone and fractured rocks of saturated zone. The ground water occurring in the unsaturated zone is not sustainable while the ground water occurring in the fractured rocks are sustainable if properly exploited. But, targeting the productive fractured rocks needs careful evaluation and systematic approach of geophysical survey owing to the heterogeneity, magmatic and metamorphic activities of multiple episodes of rocks. Hence, judicious planning in ground water exploration is warranted because of the huge money involved in drilling, manpower and time factor. In this context, an attempt has been made to locate the fractured rocks of ground water potential in the Ophiolite formations of Port Blair, South Andaman Islands using Electrical Resistivity Tomography (ERT) and Vertical Electrical Soundings (VES) since the ground water database of Andaman and Nicobar islands is poor as not much work has been carried out so far and the ground water is not properly utilised. The ERT have been carried out along different azimuth of fractures to ascertain the resistivities in vertical and horizontal direction and the conductivity and/or the resistivity of the varied fractures was also evaluated by spot VES. The 2-D Electrical Resistivity Images in conjunction with the geoelectrical parameters brought out by VES revealed that E-W fractures are expected to be productive fractures showing more conductivity as it is compared with the NE-SW and NW-SE fractures. The potentiality of the E-W fractures was also validated with the borehole data. 相似文献