Empirical assessment of rockfall and debris flow risk along the Karakoram Highway,Pakistan     

Ali  Sajid  Haider  Rashid  Abbas  Wahid  Basharat  Muhammad  Reicherter  Klaus 《Natural Hazards》2021,106(3):2437-2460

Natural Hazards - The Karakoram Highway links north Pakistan with southwest China. It passes through unique geomorphological, geological and tectonic setting. This study focused 200-km-long section...  相似文献   

MULTI-ELEMENT ANALYSIS OF COASTAL MARINE SEDIMENT, AN IAEA PROPOSED REFERENCE MATERIAL (IAEA-356)     

A. MANNAN  S. WAHEED  A. RAHMAN  S. AHMAD  I.H. QURESHI 《Geostandards and Geoanalytical Research》1993,17(2):223-226

Proposed standard reference material, coastal marine sediment (IAEA-356) recently released under the IAEA Analytical Quality Control Services programme, has been analysed by instrumental neutron activation analysis technique. Up to 32 elements have been measured using the multi-element analysis approach. The precision of measurements varied from 1.3 to 12.5% with median value of 4.9%. The quality control of the data has been validated by analysing IAEA reference material of similar matrix which shows excellent agreement with IAEA values.  相似文献   

An evaluation of the exposure in nadir observation of the JEM-EUSO mission     

《Astroparticle Physics》2013

We evaluate the exposure during nadir observations with JEM-EUSO, the Extreme Universe Space Observatory, on-board the Japanese Experiment Module of the International Space Station. Designed as a mission to explore the extreme energy Universe from space, JEM-EUSO will monitor the Earth’s nighttime atmosphere to record the ultraviolet light from tracks generated by extensive air showers initiated by ultra-high energy cosmic rays. In the present work, we discuss the particularities of space-based observation and we compute the annual exposure in nadir observation. The results are based on studies of the expected trigger aperture and observational duty cycle, as well as, on the investigations of the effects of clouds and different types of background light. We show that the annual exposure is about one order of magnitude higher than those of the presently operating ground-based observatories.  相似文献   

Accurate polynomial expressions for the density and specific volume of seawater using the TEOS-10 standard     

《Ocean Modelling》2015

A new set of approximations to the standard TEOS-10 equation of state are presented. These follow a polynomial form, making it computationally efficient for use in numerical ocean models. Two versions are provided, the first being a fit of density for Boussinesq ocean models, and the second fitting specific volume which is more suitable for compressible models. Both versions are given as the sum of a vertical reference profile (6th-order polynomial) and an anomaly (52-term polynomial, cubic in pressure), with relative errors of ∼0.1% on the thermal expansion coefficients. A 75-term polynomial expression is also presented for computing specific volume, with a better accuracy than the existing TEOS-10 48-term rational approximation, especially regarding the sound speed, and it is suggested that this expression represents a valuable approximation of the TEOS-10 equation of state for hydrographic data analysis. In the last section, practical aspects about the implementation of TEOS-10 in ocean models are discussed.  相似文献   

Source Sector Contributions to Aerosol Levels in Pakistan          下载免费PDF全文

Muhammad Zeeshaan SHAHID  LIAO Hong  QIU Yu-Lu  Imran SHAHID 《大气和海洋科学快报》2015,8(5)

Urban air pollution in Pakistan is a serious challenge and it causes significant damage to human health and ecosystems. This paper presents a modelling study using the Weather Research and Forecasting Model coupled with Chemistry(WRF-Chem) to simulate the spatial distributions and temporal variations of aerosol concentrations over Pakistan, focusing on contributions of domestic emission sectors(transport, industry, residential, and energy) to mass concentrations of sulfate(SO2–4), nitrate(NO–3), ammonium(NH+4), black carbon(BC), and organic carbon(OC) during the months of January, April, July, and October in 2010. Sensitivity studies indicate that, averaged over January, April, July, and October of 2010, energy and industry sectors have the largest contributions to SO2–4 concentrations, each of which contributes about 10%?20% to SO2– 4over the polluted eastern Pakistan. The contributions from residential and transport sectors to NO–3 concentrations reach 40%?50% in central Pakistan. The residential sector has the highest contribution of 50%–80% to BC and OC loading in northeastern and southern Pakistan. Examination of sector contributions to aerosol levels in Lahore, the most polluted city in Pakistan, suggests that reductions in emissions in the residential sector should be an efficient measure for improving particulate matter air quality in this region.  相似文献   

Instability of layered media under gravity stress     

《Russian Geology and Geophysics》2014,55(9):1146-1152

It is proposed to consider data both on the deep density distribution (gravity instability) and the bulk modulus of elasticity on estimation of the stability of layered mountain ranges. It is shown that an increase in bulk elastic rigidity with depth is the stable state of layered media in terms of energy in the field of gravity stress. In the tectonosphere, in which the moduli of elasticity are inverted (decrease) with depth, excess energy of elastic strain of volume change is generated by body forces, and it will determine the instability of the geologic medium.  相似文献   

Mineral inclusions in sapphire from the basalt-related deposit in Bo Phloi,Kanchanaburi, western Thailand: indication of their genesis     

《Russian Geology and Geophysics》2014,55(9):1087-1102

The Bo Phloi gem field in Kanchanaburi Province, Western Thailand, is closely associated with Cenozoic basalts. Blue and yellow sapphire, black spinel, and minor zircon have been mined for over three decades. The mineral inclusions observed in sapphire samples are alkali feldspar, nepheline, hercynitic spinel, zircon, manganiferous ilmenite, silica-rich enstatite, almandine–pyrope garnet, monazite, calcite, sapphirine, biotite–phlogopite mica, and staurolite. Based on their geochemical affinity, these mineral inclusions can be categorized into two main groups: felsic alkaline and contact-metamorphic, which appear to have originated from different processes. These inclusions provide new evidence for proposing a bimodal genetic model. Felsic alkaline origin is evidenced by the occurrence of a felsic alkaline inclusion suite and the REE geochemistry of sapphire-associated zircon, which indicates that most of the sapphires crystallized from a high-alkali felsic melt (probably, in the lower crust). Contact-metamorphic origin is evidenced by the presence of a contact-metamorphic inclusion suite, suggesting that some of these sapphires might also have originated from metasomatized crustal rocks and a contaminated melt along the contact zone of a basaltic intrusion (probably, in the upper mantle or lower crust).  相似文献   

Shigar valley gemstones,their chemical composition and origin,Skardu, Gilgit-Baltistan,Pakistan     

Muhammad Hassan Agheem  Mohammad Tahir Shah  Tahseenullah Khan  Mamoru Murata  Muhammad Arif  Humaira Dars 《Arabian Journal of Geosciences》2014,7(9):3801-3814

A variety of gemstones is being mined in the Shigar valley, Skardu, Pakistan. These include beryl (goshenite and aquamarine), tourmaline (schorl), garnet (almandine–spessartine), apatite, topaz, fluorite, zoisite, clinozoisite, and axinite, mostly occurring in complex or zoned pegmatites and metamorphic rocks. These have been analyzed using electron probe micro-analyzer and X-ray diffractometer. The mineral chemistry of each gemstone is similar to its respective typical gemstone variety with homogenous chemical composition. Field and chemical characteristics suggest that beryl, tourmaline, garnet, apatite, topaz, and fluorite are occurring in zoned pegmatites which are largely formed by magmatic hydrothermal fluids in the cavities and vugs within the intermediate zone. However, zoisite, clinozoisite, and axinite may have a metamorphic and/or metasomatic origin.  相似文献   

Unnoticed but important: revealing the hidden contribution of community-based religious institution of the mosque in disasters     

Abdur Rehman Cheema  Regina Scheyvens  Bruce Glavovic  Muhammad Imran 《Natural Hazards》2014,71(3):2207-2229

The role of community-based religious institutions has been largely undocumented, underestimated and overshadowed in the disaster studies literature. This paper explores the role of the mosque, a community-based religious institution, in disaster management by documenting and analysing its role in rural settings in the aftermath of the 2005 earthquake in Pakistan. The study examines the role of the mosque in relation to key actors from the state, civil society and private sector during response, relief, recovery, reconstruction and rehabilitation phases of the Pakistan earthquake. Using qualitative research methods and a case study design, this article analyses primary data collected through 5 months of fieldwork (in 2009 and 2010). The findings demonstrate the multifaceted and distinct contribution of the mosque in cultural, economic, social and political aspects of the lives of the earthquake-affected communities. Possible challenges to engagement with the mosque, both gender inclusiveness and political controversy around its role, are also raised. This research suggests that state, civil society and private sector actors involved in disaster management need to understand complex relationships involving people and their religious institutions, and their impact on the social dimension of recovery. The findings of the study contribute to the scarce knowledge about the role of community-based religious institutions including churches, mosques, synagogues and temples and call for engagement: that is, acknowledging and valuing their role for building a synergy between secular and religious efforts for disaster risk reduction and post-disaster recovery.  相似文献   

Remote sensing of scattered Natura 2000 habitats using a one-class classifier     

《International Journal of Applied Earth Observation and Geoinformation》2014

Mapping of habitats with relevance for nature conservation involves the identification of patches of target habitats in a complex mosaic of vegetation types not relevant for conservation planning. Limiting the necessary ground reference to a small sample of target habitats would greatly reduce and therefore support the field mapping effort. We thus aim to answer in this study the question: can semi-automated remote sensing methods help to map such patches without the need of ground references from sites not relevant for nature conservation? Approaches able to fulfill this task may help to improve the efficiency of large scale mapping and monitoring programs such as requested for the European Habitat Directive.In the present study, we used the maximum-entropy based classification approach Maxent to map four habitat types across a patchy landscape of 1000 km² near Munich, Germany. This task was conducted using the low number of 125 ground reference points only along with easily available multi-seasonal RapidEye satellite imagery. Encountered problems include the non-stationarity of habitat reflectance due to different phenological development across space, continuous transitions between the habitats and the need for improved methods for detailed validation.The result of the tested approach is a habitat map with an overall accuracy of 70%. The rather simple and affordable approach can thus be recommended for a first survey of previously unmapped areas, as a tool for identifying potential gaps in existing habitat inventories and as a first check for changes in the distribution of habitats.  相似文献