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51.
With the growing recognition to myriad forms of current and future threats in the mountain agriculture systems,there is a pressing need to holistically understand the vulnerability of mountain agriculture communities.The study aims to assess the biophysical and social vulnerability of agriculture communities using an indicator-based approach for the state of Uttarakhand,India.A total of 14 indicators were used to capture biophysical vulnerability and 22 for social vulnerability profiles of15285 villages.Vulnerability analysis was done at village level with weights assigned to each indicator using Analytical Hierarchical Process(AHP).The results of the study highlight the presence of very high biophysical vulnerability(0.82 ± 0.10) and high social vulnerability(0.65 ± 0.15) within the state.Based on the results,it was found that incidences of high biophysical vulnerability coincide with presence of intensified agriculture land and absence of dense forest.Higher social vulnerability scores were found in villages with an absence of local institutions(like Self Helping Groups(SHGs)),negligible infrastructure facilities and higher occupational dependence on agriculture.A contrast was observed in the vulnerability scores of villages present in the three different altitudinal zones in the study area,indicating respective vulnerability generating conditions existing in these three zones.Biophysical vulnerability was recorded to be highest in the villages falling in the lower zone and lowest in the upper zone villages;whereas,social vulnerability was found to be highest in the middle zone villages and lowest in lower zone villages.Our study aids policy makers in identifying areas for intervention to expedite agriculture adaptation planning in the state.Additionally,the adaptation programmes in the region need to be more context-specific to accommodate the differential altitudinal vulnerability profiles. 相似文献
52.
It is shown that high-frequency dispersive kinetic Alfvén waves can cause significant electron heating in the solar corona. The heating is produced by collisionless electron Landau dissipation of the parallel electron current associated with high-frequency dispersive kinetic Alfvén waves, which have a parallel electric field. 相似文献
53.
The photocatalytic decolorization and mineralization of Reactive Black 5 (RB5) dye in presence of TiO2 Degussa P25 has been studied using artificial light radiation in a shallow pond slurry reactor. The equilibrium adsorption of dye, influence of pH (3–11), catalyst load (0.5–3.0 g/L), and dye concentration (20–100 mg/L) on decolorization kinetics were studied. The effect of area to volume ratio of photoreactor on decolorization kinetics has been also studied. Mineralization studies were performed at optimized conditions of pH (3) and catalyst load (1.5 g/L). The maximum adsorption (26.5 mg/g) of dye was found to occur at pH 3. The apparent pseudo first order decolorization rate constant (kapp) value followed the order pH 3 > pH 11 > pH 9 > pH 7. As compared to available literature reduction in total organic carbon (TOC) was minimal by the time there was complete decolorization. Initial reduction in TOC was followed by subsequent increasing trend till complete decolorization. Final decreasing trend in TOC was observed only after complete decolorization. Twelve hours of treatment under experimental conditions reduced TOC content by 70% only. Discussion of results suggest that photocatalytic treatment of colored effluent under low UV intensity, and low A/V ratio may result in completely decolorized effluent but still having high COD. 相似文献
54.
55.
Sandeep A. Joshi P. Kumari S. Lal Vandana Parveen Kumar Kamal 《Journal of the Geological Society of India》2017,89(6):719-722
High frequency ground motion simulation techniques are powerful tools for designing earthquake resistant structures in seismically active regimes. Simulation techniques also provide the synthetic strong ground motion in the regions where actual records are not available (Kumar et al. 2015).These techniques require several parameters of earthquake and other seismic information proceeding to the simulation. Practically estimation of parameters is a tough task, particularly in a region with limited information. This demands a simulation technique based on the easily estimated parameters for a new site. The purposes of this paper are to briefly review existing simulation techniques and to discuss in detail the new, simple and effective semi-empirical technique (Midorikawa 1993) of strong motion simulation. 相似文献
56.
Monitoring of TDS and conductivity in groundwater in the seismically active region in NW Himalayas,India 下载免费PDF全文
Arvind Kumar Surinder Singh Bikramjit Singh Bajwa Sandeep Mahajan Rajeev Kalia Sunil Dhar 《地震科学(英文版)》2010,23(3):295-299
<正>The earthquake precursors and earthquake prediction are the burning issue among the community of earth scientists and engineers. Studies of earthquake precursory phenomena since the last several decades have shown that significant geophysical and geochemical changes may occur prior to intermediate and large earthquakes (Hartmann and Levy, 2005; Yang et al, 2005; 相似文献
57.
Jatin Srivastava Dinesh Shukla Vishal Chand Ram Naraian Harish Chandra Anant R. Nautiyal 《洁净——土壤、空气、水》2010,38(8):771-774
The presence of arsenic (As) in water is of great public concern. Arsenic exists in three common valence states viz., As(0) metalloid arsenic, As(III) (arsenite) and As(V) (arsenate). Arsenite [As(III)] is the most toxic form among arsenicals which, predominates in anaerobic conditions, generally in flooded soils and in the water with high BOD. Experiments were conducted to investigate the effect of As(III) on the mycorrhization in vetiver (Vetiveria zizanioides (L.) Nash) grass in hydroponics. Studies showed significant alteration in the mycorrhizal colonization in the roots of vetiver exposed to higher concentrations of As(III) starting from 1.0, 2.0, 3.0, 4.0 to 5.0 mg/L prepared in 5% Hoagland nutrient solution without addition of phosphate ions. Considerable reduction in the mycorrhizal intensity (M) was observed in all the treatment sets as compared to the control suggesting a negative impact of the As(III) on the mycorrhizal association. Simultaneously, the study also showed that, As(III) is toxic to the vetiver plants having mycorrhizal association however plants with non‐mycorrhizal (cleansed) roots were found to be able to survive for a longer period exposed to As(III). 相似文献
58.
Redistribution of dust particles in the ionosphere as a result of vortical motions is discussed. The following possibilities
are studied: capture and evolution of dust particles in acoustic-gravitational (AG) vortices, formation of dust vortices as
a result of involving a great number of dust particles into vortex motions, and formation of vertical dust flows (streamers).
It is shown that excitation of AG-vortices at altitudes of 110–130 km as a result of development of AG-wave instability, associated
with non-zero balance of heat fluxes, owing to solar radiation, water vapors condensation, infrared emission of the atmosphere,
and thermal conductivity, leads to a substantial transportation of dust particles and their mixing at altitudes of 110–120
km. Layers of dust particles in the ionosphere with a thickness of about a kilometer, forming at altitudes less than 120 km,
distribute within the region of existence of AG-vortical structures. As a result, at altitudes of 110–120 km, dust vortices
can appear, and transportation of particles up to altitudes of 130 km becomes possible. One of the ways of transportation
of dust particles in the ionosphere is vertical flows (streamers), which are generated by dust vortices as a result of development
of parametric instability. 相似文献
59.
H. S. Mandal A. K. Shukla P. K. Khan O. P. Mishra 《Pure and Applied Geophysics》2013,170(12):2139-2161
The Son-Narmada-Tapti lineament and its surroundings of Central India (CI) is the second most important tectonic regime following the converging margin along Himalayas-Myanmar-Andaman of the Indian sub-continent, which attracted several geoscientists to assess its seismic hazard potential. Our study area, a part of CI, is bounded between latitudes 18°–26°N and longitudes 73°–83°E, representing a stable part of Peninsular India. Past damaging moderate magnitude earthquakes as well as continuing microseismicity in the area provided enough data for seismological study. Our estimates based on regional Gutenberg–Richter relationship showed lower b values (i.e., between 0.68 and 0.76) from the average for the study area. The Probabilistic Seismic Hazard Analysis carried out over the area with a radius of ~300 km encircling Bhopal yielded a conspicuous relationship between earthquake return period (T) and peak ground acceleration (PGA). Analyses of T and PGA shows that PGA value at bedrock varies from 0.08 to 0.15 g for 10 % (T = 475 years) and 2 % (T = 2,475 years) probabilities exceeding 50 years, respectively. We establish the empirical relationships $ {\text{ZPA}}_{(T = 475)} = 0.1146\;[V_{\text{s}} (30)]^{ - 0.2924}, $ and $ {\text{ZPA}}_{(T = 2475)} = 0.2053\;[V_{\text{s}} (30)]^{ - 0.2426} $ between zero period acceleration (ZPA) and shear wave velocity up to a depth of 30 m [V s (30)] for the two different return periods. These demonstrate that the ZPA values decrease with increasing shear wave velocity, suggesting a diagnostic indicator for designing the structures at a specific site of interest. The predictive designed response spectra generated at a site for periods up to 4.0 s at 10 and 2 % probability of exceedance of ground motion for 50 years can be used for designing duration dependent structures of variable vertical dimension. We infer that this concept of assimilating uniform hazard response spectra and predictive design at 10 and 2 % probability of exceedance in 50 years at 5 % damping at bedrocks of different categories may offer potential inputs for designing earthquake resistant structures of variable dimensions for the CI region under the National Earthquake Hazard Reduction Program for India. 相似文献
60.
D. Poornima R. Shanthi S. Raja G. Vijayabaskara Sethubathi T. Thangaradjou T. Balasubramanian K. N. Babu A. K. Shukla 《Journal of the Indian Society of Remote Sensing》2013,41(3):651-662
Spatial and temporal distribution of chlorophyll a (chl a) and Total Suspended Matter (TSM) and inter comparison of Ocean Color Monitor-2 (OCM-2) and Moderate Resolution Imaging Spectro-radiometer (MODIS-Aqua) derived chlorophyll a and TSM was made along the southwest Bay of Bengal (BoB). The in-situ chl a and TSM concentration measured during different seasons were ranged from 0.09 to 10.63 μgl?1 and 11.04–43.75 mgl?1 respectively. OCM-2 and MODIS derived chl a showed the maximum (6–8 μgl?1) at nearshore waters and the minimum (0–1 μgl?1) along the offshore waters. OCM-2 derived TSM imageries showed the maximum (50–60 mgl?1) along the nearshore waters of Palk Strait and the moderate concentration (2–5 mgl?1) was observed in the offshore waters. MODIS derived minimum TSM concentration (13.244 mgl?1) was recorded along the offshore waters, while the maximum concentration of 15.78 mgl?1 was found along the Kodiakarai region. The inter-comparison of OCM-2 and MODIS chl a data (R 2 ?=?0.549, n?=?49, p?<?0.001, SEE?=?±0.117) indicate that MODIS data overestimates chl a concentration in the nearshore waters of the southern BoB compared to the OCM-2. The correlation between OCM-2 and MODIS-Aqua TSM data (R 2 ?=?0.508, N?=?53, P?<?0.001 and SEE?=?±0.024) confirms that variation in the range of values measured by OCM-2 (2–60 mgl?1) and the MODIS (13–16 mgl?1) derived TSM values. Despite problems in range of measurements, persistent cloud cover etc., the launch of satellites like OCM-2 with relatively high spatial resolutions makes job easier and possible to monitor chl a distribution and sediment discharges on day to day basis in the southwest BoB. 相似文献