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1.
CS Suma K Srinivasamoorthy K Saravanan S Gopinath R Prakash A Faizal Khan 《Arabian Journal of Geosciences》2016,9(18):703
An attempt has been made in Chinnar sub basin of Dharmapuri district, South India to isolate the geochemistry of uranium occurrences in groundwater. The geology of the area is mainly of charnockite and granite gneiss. Groundwater samples were collected for two different seasons post and pre monsoon in two different litho units (granite gneiss and charnockite) and analysed for major, minor and uranium concentrations. Higher uranium (18.45 μg L?1) has been recorded during pre monsoon season in granite gneiss with increasing pH. The saturation index calculation for the groundwater isolated minerals like uaraninite, coffinite, haiweeite and soddyite to be precipitating and uranium oxides like UO2.25, UO2.25beta, UO2.33beta as oversaturated. The Eh-pH diagram attempted represents solubility of uraninite within the pH range of 6.0 to 8.0. The study isolate uranium in groundwater of the study area is controlled by the presence of (U4O9) uranium oxide. 相似文献
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Hydro-hypsometric analysis of tropical river basins,Southwest Coast of India using geospatial technology 总被引：1，自引：0，他引：1
The key aspect in planning and management of water resources is to analyze the runoff potential and erosion status of the river basin. For the detailed investigation of hydrological response, freely available Cartosat-1 (IRS-P5) data was used for the preparation of digital elevation model (DEM). The runoff potential and type of erosive process of 22 river basins originating in the global biodiversity hotspot of Western Ghats, was inferred through hypsometric analysis. Several parameters like Hypsometric integral (HI), maximum concavity (Eh), coordinates of slope inflection point (I) given by a* and h* and normalized height of hypsometric curve (h) were extracted from the hypsometric curves and used for understanding the hydrological responses. From the hypsometric curves, the landform evolution processes were inferred. Contribution of diffusive and fluvial processes in slope degradation of the river basins was understood. Basins with lesser area (<100 km2) were found to have a positive correlation between hypsometric integral and basin area, whereas for large basins no such correlation exists. Based on the study, river basins can be prioritized for the appropriate conservation measures. 相似文献
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Summary An investigation is carried out on the unsteady boundary layer induced in an incompressible, homogeneous, viscous fluid bounded by (i) an infinite horizontal porous plate aty=0, or (ii) two parallel horizontal rigid porous plates aty=0 andy=d. The unsteady motion is generated in the above fluid configurations by moving the plate(s) impulsively in its (their) own plane with a prescribed time-dependent velocity. Solutions for the unsteady velocity field are exactly solved by the Laplace transform treatment combined with the theory of residues. The structures of the associated boundary layers are determined. The effects of suction on the solutions and the boundary layers are investigated in detail, the limiting behaviour of the unsteady solution as timet is examined and Physical interpretations of the mathematical results are given. Finally, the frictional stresses on the plates are stated without detailed calculation. 相似文献
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A baseline study of trace metals in a coral reef sedimentary environment,Lakshadweep Archipelago 总被引：3，自引：1，他引：2
Anu Gopinath S. M. Nair N. C. Kumar K. V. Jayalakshmi D. Pamalal 《Environmental Earth Sciences》2010,59(6):1245-1266
Surficial and core samples collected from the sedimentary microenvironments of Lakshadweep Archipelago were analysed for their
trace metal contents. The synoptical relations in spatial distributions with respect to environmental conditions such as pH,
organic carbon and sediment texture were inter-correlated. Some of the metals exhibited good correlations with Fe/Mn, which
reflect their similarity in distribution rather than anthropogenic enrichment. Inter-relating the variations in metal—pH relationships
with metal—organic carbon, in general, those which exhibited positive correlations with pH, displayed negative interactions
with organic carbon content and vice versa. Comparatively, higher values of Fe in the mangrove area of one of the islands
highlight the possibility of precipitation of Fe as iron sulphides, which are common in mangrove ecosystem. Based on the contamination
factors for Pb, Zn and Cd, as well as the geo-accumulation index of Cd, it can be generalised that some of the islands remain
polluted with respect to these elements. An evaluation based on pollution load index shows that none of the islands surveyed
for this study posed a serious threat in trace metal pollution. Bray Curtis similarity index was computed to find out the
similarity among metals/islands, using non-transformed data of metal concentrations. Group linkage clustering technique was
used for drawing dendrograms to show the similarity among them. 相似文献
7.
The coastal zone of the Sagar island has been studied. The island has been subjected to erosion by natural processes and to
a little extent by anthropogenic activities over a long period. Major landforms identified in the coastal area of the Sagar
island are the mud flats/salt marshes, sandy beaches/dunes and mangroves. The foreshore sediments are characterized by silty,
slightly sandy mud, slightly silty sand and silty sand. Samples 500 m inland from high waterline are silty slightly sandy
mud, and by clayey slightly sandy mud. The extent of coastline changes are made by comparing the topographic maps of 1967
and satellite imageries of 1996, 1998 and 1999. Between 1967 and 1999 about 29.8 km2 of the island has been eroded and the accreted area is only 6.03 km2. Between 1996 and 1998 the area underwent erosion of 13.64 km2 while accretion was 0.48 km2. From 1998 to 1999, 3.26 km2 additional area was eroded with meager accretion. Erosion from 1997 to 1999 was estimated at 0.74 km2 /year; however, from 1996 to 1999, the erosion rate was calculated as 5.47 km2/year. The areas severely affected by erosion are the northeastern, southwestern and southeastern faces of the island. As
a consequence of coastal erosion, the mud flats/salt marshes, sandy beaches/dunes and mangroves have been eroded considerably.
Deposition is experienced mainly on the western and southern part of the island. The island is built primarily by silt and
clay, which can more easily be eroded by the waves, tides and cyclonic activities than a sandy coast. Historic sea level rises
accompanied by land subsidence lead to differing rates of erosion at several pockets, thus periodically establishing new erosion
planes. 相似文献
8.
MURUGESAN Vasanthavigar KRISHNARAJ Srinivasamoorthy KANNUSAMY Vijayaragavan SELVARAJ Gopinath SUBRAMANYA Sarma 《地球空间信息科学学报》2011,14(1):17-26
The main objective of the study is to identify groundwater potential zones in Thirumanimuttar basin with an integrated approach using Remote Sensing and geographical information system(GIS).FCC Image of Landsat TM 30 m resolution data and topographic maps has been used to generate thematic maps like geology,geomorphology,lineament and lineament density,drain-age,drainage density,and slope map of the study area.A number of geomorphic units such as Denudational hills,structural hills,Bajadas,Colluvial plain,Pediplain,Deep Pediment and Alluvial plains have been observed.A composite groundwater potential map has been generated as very high,high,medium,low and very low based on the groundwater availability area.The upper,mid-dle and downstream of the basins have been identified as potential zones for groundwater exploration.The regions of lineaments and intersecting lineaments proved for groundwater potential zones.The data generated was validated with field checks and ob-served to be in conformity with the same. 相似文献
9.
Girish Gopinath Resmi T. R. Anil Kumar K. S. Anusree N. S. N. B. Narasimha Prasad 《Journal of the Geological Society of India》2018,91(2):198-200
This paper discusses the ancient perennial water abstraction structures—Keni—developed by the tribal communities in Wayanad district, Kerala, southwest coast of India. Keni is shallow wooden abstraction structure built in the soil zone where the water table is near or above the ground level. These traditional water abstraction structures are perfect example of water harvesting and water purification. As a preliminary assessment, a detailed survey of the Keni in the district is conducted and the result of the chemical analysis of water from the Keni is presented in this paper. Water from Kenis meet the drinking water quality standards prescribed by the BIS. 相似文献
10.
Dams and their reservoirs, constructed to manage the water scarcity problems of a region, sometimes lose whole or part of their functionality due to sedimentation. This issue, seen as a negative impact as far as reservoir life and its purpose is concerned, can be a boon to the construction industry, by providing a highly demanding construction material in the form of sand dredged from the reservoirs. Malampuzha reservoir, a multipurpose reservoir in the South Indian state of Kerala, is also losing considerable part of its storage due to siltation. This paper assesses the rate of sedimentation in Malampuzha reservoir, through bathymetric survey and suggests measures for utilization of the removable sediment. Our analysis has shown that the reservoir capacity is reduced from 226 to 205.19 Mm3; a reduction in capacity of 20.81 Mm3 in 55 years. The rate of sedimentation of the reservoir is estimated as 16.95 mm/year. The dead storage capacity of the reservoir has reduced to 47.5 % from the original at present. The composition of deposited sediments is also identified, based on which its productive use is recommended. 相似文献