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951.
Kanchan Pande J. T. Padia R. Ramesh K. K. Sharma 《Journal of Earth System Science》2000,109(1):109-115
Stable hydrogen (δD) and oxygen (δ18O) isotope ratios of the headwaters of the Indus and its tributaries, surface ice in glaciers, saline and fresh water lakes
and thermal springs in the Himalayan and Trans-Himalayan (Kashmir) region are reported. The δ5D-δ18 relationship for the river samples shows a slope of 9.12 +-0.29 which agrees well with the estimate of 8.99 ±0.33 based on
a simple Rayleigh fractionation model. The unique signature of a higher deuterium excess (d) of the ‘Western Disturbance’ is preserved in these samples. An altitude effect of -0.9 per mil/km is observed in the δ18O of Indus waters. At a lower altitude (Beas) the altitude effect is almost double, indicating that the altitude effect decreases
with elevation in this region. 相似文献
952.
Short-term geomorphic and hydrologic effects of subsidence induced by longwall mining under Burnout Creek, Utah were evaluated.
During the year after longwall mining, 0.3–1.5 m of subsidence was measured near impacted reaches of the mountain stream channel.
The major channel changes that occurred in a 700-m reach of Burnout Creek that was subsided from 1992 to 1993 were: (1) increase
in lengths of cascades and to a lesser extent glides; (2) increases in pool length, numbers and volumes; (3) increase in median
particle diameter of bed sediment in pools; and (4) some constriction in channel geometry. Most of the changes appeared short-lived,
with channel recovery approaching pre-mining conditions by 1994. In a 300-m reach of the South Fork that was subsided from
1993 to 1994, only channel constriction was observed, although any impacts on pool morphology may have been confounded by
heavy grazing in the riparian reaches during the dry summer of 1994. Similar near-channel sedimentation and loss of pool volume
between 1993 and 1994 were noted throughout Burnout Creek and in adjacent, unmined James Creek. Subsidence during the 3-year
period had no effect on baseflows or near-channel landslides.
Received: 10 April 1998 · Accepted: 21 September 1998 相似文献
953.
954.
Ripu M. KUNWAR Laxmi MAHAT Lila N. SHARMA Keshab P. SHRESTHA Hiroo KOMINEE Rainer W. BUSSMANN 《山地科学学报》2012,9(5):589-600
Underutilized plant species help to alleviate common food insufficiencies by providing alternative food supply. They also complement primary health care, furnishing raw materials where the cultivation of staple cereal crops is least feasible and health care is pursued indigenously. Research and promotion of extraction, utilization, and conservation of underutilized species lead to exploration of new staple crops and motivate people to consume in a sustainable manner. The present study describes the current status, uses, and management of underutilized plant species in Far West Nepal. The relative importance of 49 underutilized plant species was computed employing a Relative Importance (RI) technique. The use-values assigned to the species fall into six use-categories: beverage, fodder, food & edible, medicinal, vegetable and veterinary. A total of 22 species appeared in multiple use-categories, while the rest were characterized by a single use-category. Based on relative importance and frequency, Ficus semicordata, Debregesia longifolia, Girardinea diversifolia, Hydrocotyle nepalensis, Garuga pinnata, Aloe vera and Pyrus pashia offer the most potential for future. Underutilized plants proved important to folk medicine and food. These species persist because they remain useful to local people as means of subsistence, production, and primary health care. The findings are important so far as they point up the role of underutilized plants in national food security policy and health care, spelling out their potentialities and cross cutting relationships. 相似文献
955.
Interpreting characteristic drainage timescale variability across Kilombero Valley,Tanzania 总被引:1,自引:0,他引:1
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Steve W. Lyon Alexander Koutsouris Friedemann Scheibler Jerker Jarsjö Rene Mbanguka Madaka Tumbo Keven K. Robert Asha N. Sharma Ype van der Velde 《水文研究》2015,29(8):1912-1924
We explore seasonal variability and spatiotemporal patterns in characteristic drainage timescale (K) estimated from river discharge records across the Kilombero Valley in central Tanzania. K values were determined using streamflow recession analysis with a Brutsaert–Nieber solution to the linearized Boussinesq equation. Estimated K values were variable, comparing between wet and dry seasons for the relatively small catchments draining upland positions. For the larger catchments draining through valley bottoms, K values were typically longer and more consistent across seasons. Variations in K were compared with long‐term averaged, Moderate‐resolution Imaging Spectroradiometer‐derived monthly evapotranspiration. Although the variations in K were potentially related to evapotranspiration, the influence of data quality and analysis procedure could not be discounted. As such, even though recession analysis offers a potential approach to explore aquifer release timescales and thereby gain insight to a region's hydrology to inform water resources management, care must be taken when interpreting spatiotemporal shifts in K in connection with process representation in regions like the Kilombero Valley. © 2014 The Authors. Hydrological Processes published by John Wiley & Sons Ltd. 相似文献
956.
Praveen Galav N. Dashora S. Sharma R. Pandey 《Journal of Atmospheric and Solar》2010,72(17):1309-1317
We present the mean diurnal, seasonal and annual variations in TEC during the lowest solar activity phase from low latitude Indian zone recorded at Udaipur (Geog. Lat. 24.6°N, Geog. Long.73.7°E, Geomag. Lat. 15.6°N) using a GPS receiver. Seasonal variations in daytime TEC show a semiannual periodicity, with a minimum in winter. Results of seasonal variations have been compared with that of the IRI-2007 model. Model calculations reveal significant seasonal as well as longitudinal differences in TEC. Seasonal variations in the nighttime TEC reveal an annual periodicity. Near the crest of the EIA, TEC shows a very good correlation with the solar flux. The results also point to weakening of the anomaly crest as well as its spatial and temporal contraction with declining solar activity. 相似文献
957.
K. C. Sharma 《Astrophysics and Space Science》1986,125(2):299-304
The problem of thermal-convective instability of a hydromagnetic composite plasma in a stellar atmosphere has been studied with Hall effects. The criterion for monotonic instability has been found to be unchanged by the presence of Hall effects. 相似文献
958.
The thermal-convective instability of a composite rotating stellar atmosphere in the presence of a variable horizontal magnetic field is considered to include, separately, the effects of medium permeability and solute gradient. The criteria for monotonic instability in each case have been obtained which generalize the Defouw's criterion derived for thermal-convective instability in the absence of above effects. 相似文献
959.
List of forthcoming papers 相似文献
960.
The thermosolutal-convective instability of a composite stellar atmosphere is considered in the presence of variable horizontal magnetic field and collisional effects. The criteria for monotonic instability are obtained which generalize the criterion derived for thermal-convective instability in the absence of above effects. 相似文献