Distribution, Use Pattern and Prospects for Conservation of Medicinal Shrubs in Uttaranchal State, India   总被引：1，自引：0，他引：1  

Bhupendra S. Adhikari Mani M. Babu Prem L. Saklani Gopal S. Rawat 《山地科学学报》2007,4(2):155-180

The present paper gives an insight into the distribution and use pattern of medicinal shrubs in Uttaranchal State. A total of 222 medicinal and aromatic shrub species have been appended based on secondary information. Euphorbiaceae, Rosaceae, Verbenaceae, and Fabaceae have the highest repre- sentatives of medicinal shrubs. Twenty one families had one species each in medicinal use. Verbenaceae and Euphorbiaceae in the sub-tropical region, Rosaceae in the temperate region, and Ericaceae and Rosaceae in the sub-alpine and alpine regions, respectively, had the highest representatives of medicinal shrubs. The distribution of medicinal shrubs was 42 % in sub-tropical, 29 % in warm temperate, 13 % in cool temperate, 9 % in sub-alpine and 7 % in the alpine region. Of the total species, 70 medicinal shrubs were native to the Himalayas and 22 native to Himalayan region including other Hima- layan countries. The most frequently used plant parts for various ailments were leaves (31 %) and roots (23 %). Most shrubs are being used for the diseases, viz. skin diseases, dysentery, cough, fever, wounds, and rheumatism. The present paper will help in the execution of strategies for promotion and cultivation of medicinal shrubs in Uttaranchal State.  相似文献   

Generation of gravity waves within the ionosphere by transient heating during high-power wave propagation     

S. S. De  S. K. Adhikari  S. Bandyopadhyay  J. Bandyopadhyay 《Astrophysics and Space Science》1987,135(2):325-334

Generation of short-range gravity waves within the ionosphere due to inhomogenous heating in the presence of space-localized inhomogeneities during high-power radio wave-propagation has been investigated. The magnitude and from of the anticipated atmospheric wave-trains are obtained. The derived experession of electric field within the ionosphere under the stated perturbed condition may be considered to be manifested through Lorentz-force and Joule-dissipation that influence the neutral gas of the atmosphere via collision-mechanism and thereby gravity waves are launched. The expressions for the low-frequency part of the fractional pressure variations have been derived which are applied to theE-region of the ionosphere. The results are presented graphically.  相似文献   

Predicting sediment transport by interrill overland flow on rough surfaces     

Athol D. Abrahams  Gary Li  Chitra Krishnan  Joseph F. Atkinson 《地球表面变化过程与地形》1998,23(12):1087-1099

Modelling soil erosion requires an equation for predicting the sediment transport capacity by interrill overland flow on rough surfaces. The conventional practice of partitioning total shear stress into grain and form shear stress and predicting transport capacity using grain shear stress lacks rigour and is prone to underestimation. This study therefore explores the possibility that inasmuch as surface roughness affects flow hydraulic variables which, in turn, determine transport capacity, there may be one or more hydraulic variables which capture the effect of surface roughness on transport capacity suffciently well for good predictions of transport capacity to be achieved from data on these variables alone. To investigate this possibility, regression analyses were performed on data from 1506 flume experiments in which discharge, slope, water temperature, rainfall intensity, and roughness size, shape and concentration were varied. The analyses reveal that 89·8 per cent of the variance in transport capacity can be accounted for by excess flow power and flow depth. Including roughness size and concentration in the regression improves that explained variance by only 3·5 per cent. Evidently, flow depth, when used in combination with excess flow power, largely captures the effect of surface roughness on transport capacity. This finding promises to simplify greatly the task of developing a general sediment equation for interrill overland flow on rough surfaces. Copyright © 1998 John Wiley & Sons, Ltd.  相似文献   

Magnetic and radiometric signatures over a Proterozoic massive sulfide setting of northern fringe of Dalma Volcanics,eastern India: An implication to metallogeny     

Pramod Kumar Yadav  P. K. Adhikari  Shalivahan  Anurag Tripathi  Shailendra Singh  Roshan K. Singh  Ashish K. Bage 《Journal of the Geological Society of India》2017,89(6):705-710

Magnetic and radiometric surveys were carried out over a felsic dominated rifted margin of Proterozoic volcanic terrain of a mobile belt in the eastern India. The studies were made in blocks I and II of 0.65 sq km and 0.70 sq km respectively over a previously identified conductor in the northern fringe of Dalma Volcanics (DVs). In general, both the blocks show high magnetic signature associated with sulfide mineralisation. The interpretation of magnetic data suggests that nature of the causative source is mainly horizontal cylinder in both the blocks. The depth to the top of the causative source is about 25 m in both the blocks and extends upto 60 m in block I and 40m in block II. Gamma count rate exhibits about a factor of two to three enhancements above the field background for both the blocks. The obtained iso-rad maps are similar to uranium and copper belt in the Singhbhum shear zone south of the study area. The anomalous radiometric signature of the residual soil/rock of the area indicates towards hydrothermal alteration. The detailed magnetic surveys and preliminary iso-rads results seems quite encouraging and may be attributed to VMS setting in the area and potential sulfide mineralisation with uranium mineral association in the DVs province.  相似文献   

Provenance evolution of collapse graben fill in the Himalaya—The Miocene to Quaternary Thakkhola-Mustang Graben (Nepal)     

Basanta Raj Adhikari  Michael Wagreich 《Sedimentary Geology》2011,233(1-4):1-14

This study focuses on the detailed provenance evolution of young, syn- to post-orogenic extensional grabens in orogens like the Himalaya to trace the tectonic history of such late-stage basins, using the Neogene Thakkhola-Mustang Graben as a case study. The graben is situated within the Tibetan-Tethys zone and is filled with > 870 m of continental deposits of Miocene to Holocene age-. Based on logged sections within the predominantly alluvial to coarse-grained fluvial fill of the graben we investigated paleocurrent data and the petrology of sandstones and conglomerates including heavy minerals studies to interpret provenance and source areas in detail. Significant changes are recorded by slight differences in heavy mineral and pebble compositions.The sandstones can be classified as lithic greywackes, lithic arkoses and feldspathic litharenites. Sandstone, mudstone, quartzite and some granite clasts are dominant in conglomerates of the central part of the graben. Tetang Formation conglomerates of Miocene age comprise mostly clasts of Mesozoic rocks with an eastern provenance, consistent with measured paleocurrent directions. All paleocurrent data and compositional analyses of imbricated conglomerates of the Miocene–Pliocene Thakkhola Formation in the northeast of the graben suggest that clasts were derived from eastern source areas comprising mainly Mesozoic rocks whereas Paleozoic clasts of a western to northern source area predominate in the centre of the graben.Heavy mineral analysis indicates that tourmaline, staurolite, zircon, garnet and apatite constitute a significant proportion of the assemblages of all formations through time whereas epidote, andalusite, kyanite, chloritoid, hornblende, chrome-spinel, rutile and amphiboles are less common. These assemblages reflect in general stable minerals and low to high-grade metamorphic source rocks, and are principally controlled by reworking of older, passive margin sediments of the Tibetan-Tethys zone as indicated by provenance discrimination diagrams.Three successive stages in provenance evolution were recognized: (1) The Miocene Tetang Formation, characterized by higher kyanite values, corresponding to the Himalayan foreland evolution; (2) the Thakkhola Formation, characterized by granite clasts and significantly higher amounts of andalusite, indicating source area expansion and erosion of the Mustang-Mugu granites to the northwest; (3) the Upper Pleistocene/Holocene Kaligandaki Formation, bearing higher amounts of epidote/klinozoisite and ophiolite and high-pressure/low temperature detritus as indicated by chrome spinel and blue amphiboles, derived from the north-lying Indus-Tsangpo suture zone. The change in source areas from the Miocene/Pliocene to the Late Pleistocene/Holocene is interpreted as a result of the evolution from an initial stage of high-angle normal faulting and collapse basin formation to a low-angle extensional detachment basin system.  相似文献   

Epiphytic orchids and their ecological niche under anthropogenic influence in central Himalayas,Nepal   总被引：1，自引：1，他引：0  

Yagya Prasad Adhikari  Anton Fischer  Hagen Siegfried Fischer 《山地科学学报》2016,13(5):774-784

The survival chance of epiphytic orchids today not only depends on the natural site conditions required by the orchids but also on anthropogenic changes in site conditions.This study answers two questions:(1) What is the ecological niche of the different epiphytic orchid species?(2) What are the ecological factors that threaten epiphytic orchid's population under anthropogenic disturbances? Our study area was the Kathmandu valley,Nepal,with its subtropical forest.We established 156 systematically selected sampling points in the Kathmandu area covering different types of ecosystems under human impacts such as densely populated area,agricultural land,mixed agricultural and settled area,old tree patches,and a natural forest in a national park.The ecological niche of the orchid species was analyzed with a principal component analysis(PCA).The correlations between the different site factors were statistically significant.Spearman's rank correlation matrices showed that the variables land-use intensities with altitude,and height with diameter in breast height(dbh) of host had the highest significant positive correlation coefficient(0.67 and 0.64 respectively).On the other hand,host bark p H and altitude as well as land use had a significantly strong negative correlation coefficient(-0.80 and-0.61,respectively).Different epiphytic orchid species interact differently with the given set ofenvironmental factors:for occurrence of Vanda cristata there is no single environmental factor of special influence,while for Rhynchostylis retusa high bark p H and high light availability are important.First two axis of the PCA explained more than 50% of the total variance.Most orchid species occupy a specific,narrow niche in this ecological space.The main causes of anthropogenic influence of orchid population in the Kathmandu Valley are loss of adequate host trees(species and size) and increasing air pollution,resulting in increasing host bark p H.  相似文献   

Controlled Blasting for Removal of Concrete Plugs in Draft Tube Tunnels at Sardar Sarovar Project     

G. R. Adhikari  A. I. Theresraj  R. Balachander  R. N. Gupta 《Fragblast: International Journal for Blasting and Fragmentation》2001,5(4):221-234

During construction of the Sardar Sarovar (Narmada) Hydro Electric Project in India, an unprecedented flood entered the power house cavern through draft tube tunnels and caused damage to underground structures. After this incident, these draft tubes were plugged with concrete/reinforced concrete to prevent future flooding. After heavy gates were erected at the exit end of the draft tube tunnels, these plugs had to be removed by drilling and blasting without causing any damage to the concrete lining and the ribs erected in the tunnels. Controlled blasting was designed and executed successfully for removal of the plugs in the same manner as for tunnel blasting. This paper describes the details of concrete plugs, details of drilling and blasting adopted, and some interesting observations in respect of drilling and blasting in the concrete plugs. A seismic method based on the measurement of P-wave velocity in the concrete lining before and after blasting was used to quantify the changes (damage) to concrete lining.  相似文献   

Some aspects of cast blasting techniques for dam construction     

G. R. Adhikari  R. N. Gupta 《Geotechnical and Geological Engineering》1989,7(4):301-313

Summary A proposal is under consideration to construct a dam on an experimental basis by a cast (or directional) blasting technique, DBT. The dam site is located at Bharari Khad, a tributary of the Sutlaz river in Himachal Pradesh. Site investigations have been completed and a large scale blast has been designed for construction of the experimental dam.The paper describes the basic design concept of DBT and application of throw and caving methods for construction of dams. The preliminary tests required to design the blasting pattern are detailed. The technique has a great potential because it reduces construction cost and time particularly in inaccessible mountain regions.  相似文献   

Response of Concrete and Masonry Dams to Ground Vibration due to Blasting     

G. R. Adhikari  A. I. Theresraj  R. N. Gupta 《Fragblast: International Journal for Blasting and Fragmentation》2004,8(1):41-49

The safety and stability of concrete and masonry dams is a great concern when blasting has to be conducted close to these dams in order to construct small hydro-electric projects. There is a danger of ground vibration amplification to those residential-type buildings that are built close to these dams.

Responses of three concrete and masonry dams were measured directly by conducting a number of blasts and by monitoring vibration in the ground as well as on the dams. The amplitudes and frequencies of the motions were analysed and vibration attenuation relations were derived. These relations were used to compare the vibration levels on the dams with those in the ground.

Because of close-in construction blasts that produced high frequency ground vibrations, there was no amplification of the ground vibrations by these dams. The measured amplitudes of ground vibration were comparable to those of the dams.  相似文献   

Analysis of the Statistical Behaviour of Daily Maximum and Monthly Rainfall Data at New Delhi During Monsoon Period     

C. V. Singh  R. S. Adhikari  H. P. Garg 《大气科学进展》2002,19(3):425-432

1．IRt回*CtZOllIndian Summer Monsoon Varlablllty Is a muchdscussed and researched field,yet thereIs a considerable scope IOr further work and It Is understanding．The south—west monsoonwhich contributes more than 75%of the annual ra!nfa!lin a major port!on of Ind!a,Is thespring of!he nallonaleconomy．The ralnmH has Qo sustain山e Increasing needs ofagrlculturelrrlgatlon,the Increasing population and the rapid Industrlallsatlon．It Is lowever noted thatthe monsoon rainfall over differe…  相似文献