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21.
Glacial mass balance changes in the Karakoram and Himalaya based on CMIP5 multi-model climate projections 总被引:1,自引:0,他引:1
Rajiv K. Chaturvedi Anil Kulkarni Yogesh Karyakarte Jaideep Joshi G. Bala 《Climatic change》2014,123(2):315-328
The impact of future climate change on the glaciers in the Karakoram and Himalaya (KH) is investigated using CMIP5 multi-model temperature and precipitation projections, and a relationship between glacial accumulation-area ratio and mass balance developed for the region based on the last 30 to 40 years of observational data. We estimate that the current glacial mass balance (year 2000) for the entire KH region is -6.6?±?1 Gta?1, which decreases about sixfold to -35?±?2 Gta?1 by the 2080s under the high emission scenario of RCP8.5. However, under the low emission scenario of RCP2.6 the glacial mass loss only doubles to -12?±?2 Gta?1 by the 2080s. We also find that 10.6 and 27 % of the glaciers could face ‘eventual disappearance’ by the end of the century under RCP2.6 and RCP8.5 respectively, underscoring the threat to water resources under high emission scenarios. 相似文献
22.
Vulnerability and adaptation to climate variability and water stress in Uttarakhand State, India 总被引:1,自引:0,他引:1
Ulka Kelkar Kapil Kumar Narula Ved Prakash Sharma Usha Chandna 《Global Environmental Change》2008,18(4):564
This paper presents a participatory approach to investigate vulnerability and adaptive capacity to climate variability and water stress in the Lakhwar watershed in Uttarakhand State, India. Highly water stressed microwatersheds were identified by modelling surface runoff, soil moisture development, lateral runoff, and groundwater recharge. The modelling results were shared with communities in two villages, and timeline exercises were carried out to allow them to trace past developments that have impacted their lives and livelihoods, and stimulate discussion about future changes and possible adaptation interventions. 相似文献
23.
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
24.
Hoang Phan Hai Yen Binh Thai Pham Tran Van Phong Duong Hai Ha Romulus Costache Hiep Van Le Huu Duy Nguyen Mahdis Amiri Nguyen Van Tao Indra Prakash 《地学前缘(英文版)》2021,12(5):54-68
The groundwater potential map is an important tool for a sustainable water management and land use planning,particularly for agricultural countries like Vietnam. In this article, we proposed new machine learning ensemble techniques namely Ada Boost ensemble(ABLWL), Bagging ensemble(BLWL), Multi Boost ensemble(MBLWL),Rotation Forest ensemble(RFLWL) with Locally Weighted Learning(LWL) algorithm as a base classifier to build the groundwater potential map of Gia Lai province in Vietnam. For this study, eleven conditioning factors(aspect, altitude, curvature, slope, Stream Transport Index(STI), Topographic Wetness Index(TWI), soil, geology,river density, rainfall, land-use) and 134 wells yield data was used to create training(70%) and testing(30%)datasets for the development and validation of the models. Several statistical indices were used namely Positive Predictive Value(PPV), Negative Predictive Value(NPV), Sensitivity(SST), Specificity(SPF), Accuracy(ACC),Kappa, and Receiver Operating Characteristics(ROC) curve to validate and compare performance of models. Results show that performance of all the models is good to very good(AUC: 0.75 to 0.829) but the ABLWL model with AUC = 0.89 is the best. All the models applied in this study can support decision-makers to streamline the management of the groundwater and to develop economy not only of specific territories but also in other regions across the world with minor changes of the input parameters. 相似文献
25.
Om Prakash Dubey 《Journal of the Indian Society of Remote Sensing》1985,13(2):47-52
Piedmont zone is made up of unconsolidated material. They act as a recharge area for Tarai. Population density in this zone is comparatively less, Economical and social conditions of people in this region is very poor. Agriculture is only source of livehood and economy, Modern Agricultural activities are only successfull if assured water supply is available. Remote Sensing Techniques provide data source which can be utilised for evaluating water resources. It has been assumed that the ground water regime of the zone wil not be disturbed and only the amount recharged will be utilised. Rainfall recharge to ground water has been evaluated using Remotely Sensed Data. A major part of the recharged volume is not being utilised. Systems approach has been used to evolve an optimal cropping pattern. 相似文献
26.
The predatory potentiality of G. affinis and P. reticulata fishes on cyclops was tested by ‘no-choice’ and ‘choice’ experiments. In ‘no-choice’ experiments predation increased significantly with the number of cyclops exposed (1, 3, 5, 7 and 10 preys) and decreased with the increase in the water volume (1, 2 and 3 litres) in case of both the fishes. A similar trend for cyclops predation was observed in ‘choice’ experiments. The relative rate of predation of G. affinis and P. reticulata was more in ‘no-choice’ as compared to in ‘choice’ experiments. However, the predatory efficacy of G. affinis was relatively higher than that of P. reticulata in all the experiments. The comparative rate of predation on three zooplanktons by G. affinis and P. reticulata showed that Daphnia spec. was most susceptible to predation by both the fishes. It was followed by calanoids and the least preferred prey being cyclops. 相似文献
27.
Dubey Om Prakash Niwas Sri Awasthi A. K. 《Journal of the Indian Society of Remote Sensing》1986,14(1):39-44
Journal of the Indian Society of Remote Sensing - Development activities must be compatible for possibilities and limitation of natural environment and resources. Predevelopmental analysis must... 相似文献
28.
A. J. Prakash P. Palroy D. D. Misra 《Fragblast: International Journal for Blasting and Fragmentation》2004,8(1):51-60
This paper presents the influence of various discontinuities, natural or artificial, on magnitude and frequencies of blast induced ground vibrations. These discontinuities were geological faults, a pond, a shaft incline, a trench and a pre-split plane interposed in the path of vibration propagation. In the post-trench region, ground vibrations in terms of peak particle velocity were significantly reduced and dominant frequencies in higher bands were consequently observed. Depth of trench with respect to blastholes were varied and consequent vibration characteristics were analyzed. The techniques of creating a trench and pre-split plane were successfully implemented in controlling vibration and in increasing the explosives charge to meet the scheduled production target of an opencast mine. Comparisons of ground vibration characteristics affected by a trench and a pre-split plane of the same depth are described in the text. The findings lead to the conclusion that such experimental data are necessary for production blasting in open cast mines under constrained conditions. 相似文献
29.
A critical analysis of CH, NH, OH, C2, and CN molecules/radicals has been made in twenty-four F- and early G-type dwarfs at different effective temperature as well as in new constructed model atmosphere. Molecular indices of bandheads ofA-X system of CH, NH, OH, C2, and CN have been obtained by using the data available in the literature (thirteen-colour and eight-colour photometry).Besides, some interesting plots of the molecular indices vs eff, molecular abundances and molecular indices vs dissociation energy, reduced equivalent widths and FCF's vs dissociation energy for respective molecules have also been enumerated. It is found that the molecular indices at bandheads ofA-X system of CH, NH, OH, C2, and CN are approximately constant (5810–6570 K). It is to be noted that the molecular indices decrease in the order OH, NH, CH, C2, and CN at a given temperature.The dissociation equilibrium of CH, NH, OH, C2, and CN is considered at 5810, 6570, and 7160 K phases in model atmosphere. At standard scale of abundance the molecular abundance and molecular index decrease in the order OH, NH, CH, C2, and CN at any given phase, however, CN abundance and index increase (eff=0.867-0.767). The amplitude of abundance and index variation decrease in the order NH, OH, CH, C2, and CN (eff=0.767-0.704).The reduced equivalent width decrease in the order OH, NH, CH, and C2 and FCF's decrease in the order CH, OH, NH, CN, and C2.The confrontation of models and observations of spectra of F- and early G-type dwarfs of parent molecules is of primary importance to investigate the physical conditions within atmospheres. Reliable excitation models are also requisite for interpreting spectroscopic observations of parent molecules and deriving molecular abundances. 相似文献
30.
Dynamic Subsidence Characteristics in Jharia Coalfield,India 总被引:1,自引:0,他引:1
Amar Prakash Ajay Kumar Kalendra Bahadur Singh 《Geotechnical and Geological Engineering》2014,32(3):627-635
Surface ground movements are usually described by a number of characteristic indices such as vertical displacement, horizontal strain and slope, which are an inevitable consequence of underground mining. Every point at the surface over a panel is subjected to strain and slope during mining and its investigation is essential to assess the safety of surface structures. Therefore, the behaviour of dynamic active and residual subsidence was studied for a few panels of Jharia coalfield. The subsidence and slope were linearly related to time. Compressive and tensile strains showed typical fluctuating characteristic behaviour. The rate of mining being a key and controlling parameter for rate of subsidence their inter-relationship was developed, which showed a rational trend. Compressive and tensile strains and slope showed poor correlation with rate of face advance. 相似文献