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Sample records for range-potwar plateau region

  1. New transhumance in the Mahafaly Plateau region in Madagascar

    African Journals Online (AJOL)

    ). ... Elle. ARTICLE http://dx.doi.org/10.4314/mcd.v11i1.3. The cattle raiders leave us no choice: New transhumance in the Mahafaly Plateau region in. Madagascar. Johanna F. ...... during fifteen years' captivity on that island. T. Fisher Unwin ...

  2. Microbial community structures and functions of wastewater treatment systems in plateau and cold regions.

    Science.gov (United States)

    Fang, Dexin; Zhao, Gen; Xu, Xiaoyi; Zhang, Qian; Shen, Qiushi; Fang, Zhuoyao; Huang, Liping; Ji, Fangying

    2017-10-19

    Wastewater treatment plants (WWTPs) in plateau regions have unique microbial community structures. In this study, Illumina high-throughput sequencing technology was applied to investigate microbial communities of plateau WWTPs. The research showed that microbial diversities and richness were negatively associated with the altitude and positively to the water temperature to a certain extent. The dominant phyla of plateau and control WWTPs were similar, which mainly included Proteobacteria, Bacteroidetes, Chloroflexi and Firmicutes. In plateau WWTPs, the LEfSe analysis found 4 biomarkers which can catabolize aromatic compounds, indicating the microorganisms that can degrade refractory organics might survive better in plateau WWTPs. The analysis of functional genera and enzymes showed that there was no significant difference in abundances of organic degrading bacteria, but the nitrogen removal bacteria were less abundant and phosphorus removal bacteria were more abundant in plateau WWTPs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. High-Resolution Regional Phase Attenuation Models of the Iranian Plateau and Surrounding Regions

    Science.gov (United States)

    2014-03-03

    this region. Igneous rocks tend to get younger towards the eastern part of the Bitlis suture and Kars plateau (e.g. Keskin, 2003), which is consistent...Pg and Sn. 15. SUBJECT TERMS variational analysis, adjoint method, Data assimilation 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF...latite with minor basalt) volcanic rocks (Berberian and King, 1981) suggesting the presence of extensive crustal melting. Sahand (ca. 3800 m) is

  4. [Regional spatial patterns of water circumstances in loess plateau area based GIS].

    Science.gov (United States)

    Hu, Liangjun; Shao, Ming'an

    2004-11-01

    Based on the integration of GIS and geo-synthesis analysis, the water circumstances for plant growth in the Shaanxi Loess Plateau area were studied and a map reflecting regional water circumstances at the scale of 1:500,000 was made. The results showed that the water circumstances for plant growth in the Loess Plateau area were affected by the integration of precipitation soil texture, loess deposition, geomorphology and coverage, and could be measured by sub-indicators from the mentioned aspects. The index from the view point of plant development was used for the water circumstance assessment. The water circumstances of the Loess Plateau including forest zone, shrub zone and grassland zone appeared a complex spatial mosaic structure, and the main of the plateau was suitable for forestry which meant the plateau had an expected potential for eco-restoration.

  5. Regional Wave Propagation in and around the Tibetan Plateau,

    Science.gov (United States)

    1995-08-14

    displays. The path to AMDO does not enter the north- ern plateau anomalous zone, while the paths to WNDO, ERDO, and BUDO represent increasing path...zone. At BUDO , the Sn waveform is essentially a broad step, significantly different from the more pulse-like Pn waveform. This difference is consistent

  6. Extensional Seismogenic Stress and Tectonic Movement on the Central Region of the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Jiren Xu

    2009-01-01

    Full Text Available Various earthquake fault types, mechanism solutions and stress fields, as well as GPS and geothermal data are analyzed for the study of the crustal movements on the Tibetan plateau and their tectonic implications. The results show that a lot of the normal faulting type-event concentrated at altitudes greater than 4000 m on the central Tibetan plateau. The altitudes concentrating normal faulting type-events can be zoned two parts: the western part, the Lhasa block, and the eastern part, the Qiangtang-Changdu region. The azimuths of T-axes are in a general E-W direction in the Lhasa block and NW-SE or NNW-SSE in the Qiangtang-Changdu region at the altitudes of the Tibetan plateau. The tensional stresses in E-W direction and NW-SE direction predominate normal faulting earthquake occurrence in the Lhasa block and the Qiangtang-Changdu region, respectively. The slipping displacements of the normal-faulting-type events have great components in near E-W direction and NW-SE direction in the Lhasa block and the Qiangtang-Changdu region, respectively. The extensions are probably an eastward or southeastward extensional motion, being mainly tectonic activity phenomena in the plateau altitudes. The extensional motions due to normal-fault earthquakes are important tectonic activity regimes on the high altitudes of the plateau. The easterly crustal extensions on the plateau are attributable to the gravitational collapse of the high plateau and eastward extrusion of hotter mantle materials beneath the eastern boundary of the plateau. Numbers of thrust-fault and strike-slip-fault earthquakes with strong compressive stress in a general NNE-SSW direction occur on the edges of the plateau.

  7. Surface ozone at Nam Co in the inland Tibetan Plateau: variation, synthesis comparison and regional representativeness

    Science.gov (United States)

    Yin, Xiufeng; Kang, Shichang; de Foy, Benjamin; Cong, Zhiyuan; Luo, Jiali; Zhang, Lang; Ma, Yaoming; Zhang, Guoshuai; Rupakheti, Dipesh; Zhang, Qianggong

    2017-09-01

    Ozone is an important pollutant and greenhouse gas, and tropospheric ozone variations are generally associated with both natural and anthropogenic processes. As one of the most pristine and inaccessible regions in the world, the Tibetan Plateau has been considered as an ideal region for studying processes of the background atmosphere. Due to the vast area of the Tibetan Plateau, sites in the southern, northern and central regions exhibit different patterns of variation in surface ozone. Here, we present continuous measurements of surface ozone mixing ratios at Nam Co Station over a period of ˜ 5 years (January 2011 to October 2015), which is a background site in the inland Tibetan Plateau. An average surface ozone mixing ratio of 47.6 ± 11.6 ppb (mean ± standard deviation) was recorded, and a large annual cycle was observed with maximum ozone mixing ratios in the spring and minimum ratios during the winter. The diurnal cycle is characterized by a minimum in the early morning and a maximum in the late afternoon. Nam Co Station represents a background region where surface ozone receives negligible local anthropogenic emissions inputs, and the anthropogenic contribution from South Asia in spring and China in summer may affect Nam Co Station occasionally. Surface ozone at Nam Co Station is mainly dominated by natural processes involving photochemical reactions, vertical mixing and downward transport of stratospheric air mass. Model results indicate that the study site is affected differently by the surrounding areas in different seasons: air masses from the southern Tibetan Plateau contribute to the high ozone levels in the spring, and enhanced ozone levels in the summer are associated with air masses from the northern Tibetan Plateau. By comparing measurements at Nam Co Station with those from other sites on the Tibetan Plateau, we aim to expand the understanding of ozone cycles and transport processes over the Tibetan Plateau. This work may provide a

  8. Aeolian processes during the Holocene in Gannan Region, Eastern Tibetan Plateau

    Science.gov (United States)

    Yang, S.; Cheng, T.; Li, S.; Liang, M.

    2016-12-01

    Aeolian desertification occurring in the Tibetan Plateau has received attention recently for it has become a severe environmental problem by accelerating the grassland degradation and eco-environment damage. The Gannan Region is located in the northeastern Tibetan Plateau with a mean altitude of 3500m. It is highly sensitive to global environmental change and human disturbance. Serious soil erosion and desertification and extensive land degradation have caused heavy eco-environmental impacts. To investigate the evolution of the desertification in Holocene in the Plateau is of great importance for understanding the desertification trend under the global changes in the Tibetan Plateau. Loess and aeolian sands is a key geological archive related to desertification processes and the past environment changes. In this study a typical 8.5m-thick loess-sands profile named MQQ, was selected at the Maqu city. It is situated on the first terrace (T1) of the Yellow River. Detailed accelerator mass spectrometry (AMS) 14C dating of bulk organic matter content has shown the Aeolian sediments of the MQQ section occurring since the early Holocene. the mass-specific frequency-dependent magnetic susceptibility (χfd) and grainsize records show a clear upward increase in the contents of superparamagnetic grains and fine fractions in grain size, which indicates a gradual wetting trend during the Holocene.The sediment rates change from very high in the early Holocene to low values after 8.2 ka. The wetting process can be divided into three steps: 10.0-8.2 ka, 8.2-3.0 ka and 3.0-present. It indicates that the climate in the eastern Tibetan Plateau was dry during the early Holocene. After that the climate was getting wet gradually. The variations of the westerlies and the Asian monsoon may cause the environmental change in this region.

  9. Lithospheric Velocity Structure of the Anatolain plateau-Caucasus-Caspian Regions

    Energy Technology Data Exchange (ETDEWEB)

    Gok, R; Mellors, R J; Sandvol, E; Pasyanos, M; Hauk, T; Yetirmishli, G; Teoman, U; Turkelli, N; Godoladze, T; Javakishvirli, Z

    2009-04-15

    Anatolian Plateau-Caucasus-Caspian region is an area of complex structure accompanied by large variations in seismic wave velocities. Despite the complexity of the region little is known about the detailed lithospheric structure. Using data from 29 new broadband seismic stations in the region, a unified velocity structure is developed using teleseismic receiver functions and surface waves. Love and Rayleigh surface waves dispersion curves have been derived from event-based analysis and ambient-noise correlation. We jointly inverted the receiver functions with the surface wave dispersion curves to determine absolute shear wave velocity and important discontinuities such as sedimentary layer, Moho, lithospheric-asthenospheric boundary. We combined these new station results with Eastern Turkey Seismic Experiment results (29 stations). Caspian Sea and Kura basin underlained by one of the thickest sediments in the world. Therefore, short-period surface waves are observed to be very slow. The strong crustal multiples in receiver functions and the slow velocities in upper crust indicate the presence of thick sedimentary unit (up to 20 km). Crustal thickness varies from 34 to 52 km in the region. The thickest crust is in Lesser Caucasus and the thinnest is in the Arabian Plate. The lithospheric mantle in the Greater Caucasus and the Kura depression is faster than the Anatolian Plateau and Lesser Caucasus. This possibly indicates the presence of cold lithosphere. The lower crust is slowest in the northeastern part of the Anatolian Plateau where Holocene volcanoes are located.

  10. Geology of the Thaumasia region, Mars: Plateau development, valley origins, and magmatic evolution

    Science.gov (United States)

    Dohm, J.M.; Tanaka, K.L.

    1999-01-01

    We have constructed the complex geologic history of the Thaumasia region of Mars on the basis of detailed geologic mapping and relative-age dating of rock units and structure. The Thaumasia plateau dominates the region and consists of high lava plains partly surrounded by rugged highlands, mostly of Noachian and Hesperian age. Long-lived faulting centered near Syria Planum and at lesser sites produced radiating narrow grabens during the Noachian through Early Amazonian and concentric wrinkle ridges during the Late Noachian and Early Hesperian. Fault activity peaked during the Noachian and waned substantially during Late Hesperian and Amazonian time. Volcanism on the Thaumasia plateau was particularly active in comparison with other martian cratered highlands, resulting in fourteen volcanoes and numerous outcrops of smooth, ridged, and lobate plains materials. A particularly extensive set of overlapping lava-flow units was emplaced sequentially from Thaumasia Planum to Syria Planum, spanning from the Late Noachian to the Late Hesperian; lobate flows succeeded smooth flow at the beginning of the Late Hesperian. Deep crustal intrusion and a thickened, buoyant crust may have caused the uplift of the plateau during the Noachian and Early Hesperian, resulting in outward-verging fold-and-thrust plateau margins. This structural style appears similar to that of the young ranges of the Rocky Mountains in the western U.S. Within the plateau, several sites of volcanotectonic activity and valley erosion may be underlain by large and perhaps long-lived magmatic intrusions. One such site occurs at the headland of Warrego Valles. Here, at least two episodes of valley dissection from the Noachian to Early Hesperian occurred during the formation of two nearby rift systems. The site also is a locus of intersection for regional narrow grabens during the Late Noachian and Early Hesperian. However, at the site, such faults diverge or terminate, which suggests that a resistant body of

  11. Earthquake focal parameters and lithospheric structure of the anatolian plateau from complete regional waveform modeling

    Energy Technology Data Exchange (ETDEWEB)

    Rodgers, A

    2000-12-28

    This is an informal report on preliminary efforts to investigate earthquake focal mechanisms and earth structure in the Anatolian (Turkish) Plateau. Seismic velocity structure of the crust and upper mantle and earthquake focal parameters for event in the Anatolian Plateau are estimated from complete regional waveforms. Focal mechanisms, depths and seismic moments of moderately large crustal events are inferred from long-period (40-100 seconds) waveforms and compared with focal parameters derived from global teleseismic data. Using shorter periods (10-100 seconds) we estimate the shear and compressional velocity structure of the crust and uppermost mantle. Results are broadly consistent with previous studies and imply relatively little crustal thickening beneath the central Anatolian Plateau. Crustal thickness is about 35 km in western Anatolia and greater than 40 km in eastern Anatolia, however the long regional paths require considerable averaging and limit resolution. Crustal velocities are lower than typical continental averages, and even lower than typical active orogens. The mantle P-wave velocity was fixed to 7.9 km/s, in accord with tomographic models. A high sub-Moho Poisson's Ratio of 0.29 was required to fit the Sn-Pn differential times. This is suggestive of high sub-Moho temperatures, high shear wave attenuation and possibly partial melt. The combination of relatively thin crust in a region of high topography and high mantle temperatures suggests that the mantle plays a substantial role in maintaining the elevation.

  12. Intrinsic vulnerability assessment of Sette Comuni Plateau aquifer (Veneto Region, Italy).

    Science.gov (United States)

    Cucchi, Franco; Franceschini, Giuliana; Zini, Luca; Aurighi, Marina

    2008-09-01

    Maps illustrating the different degrees of vulnerability within a given area are integral to environmental protection and management policies. The assessment of the intrinsic vulnerability of karst areas is difficult since the type and stage of karst development and the related underground discharge behavior are difficult to determine and quantify. Geographic Information Systems techniques are applied to the evaluation of the vulnerability of an aquifer in the alpine karst area of the Sette Comuni Plateau, in the Veneto Region of northern Italy. The water resources of the studied aquifer are of particular importance to the local communities. This aquifer must therefore be protected from both inappropriate use as well as possible pollution. The SINTACS and SINTACS P(RO) K(ARST) vulnerability assessment methods have been utilized here to create the vulnerability map. SINTACS P(RO) K(ARST) is an adaptation of the parametric managerial model (SINTACS) to karst hydrostructures. The vulnerability map reveals vast zones (81% of the analyzed areas) with a high degree of vulnerability. The presence of well-developed karst structures in these highly vulnerable areas facilitate water percolation, thereby enhancing the groundwater vulnerability risk. Only 1.5 of the studied aquifer have extremely high-vulnerability levels, however these areas include all of the major springs utilized for human consumption. This vulnerability map of the Sette Comuni Plateau aquifer is an indispensable tool for both the effective management of water resources and as support to environmental planning in the Sette Comuni Plateau area.

  13. Regional chemical setting of the Apollo 16 landing site and the importance of the Kant Plateau

    Science.gov (United States)

    Andre, C. G.; El-Baz, F.

    1982-01-01

    Orbital X-ray data from the Apollo 16 region indicate that physiographic units identified before the lunar mission can be classified as chemical units as well. The Descartes Mountains, however, appear to be an extension of the Kant Plateau composition that is unusually anorthositic and resembles farside terra. The Cayley Plains have closer affinities to basaltic materials than terra materials, physically, spectrally and chemically. The Theophilus impact, 330 km east of the landing site, excavated magnesium-rich basalts from below less-magnesian flows in Mare Nectaris; but, mafic ejecta was substantially blocked from the Apollo 16 site by the Kant Plateau that rises 5 km above the level of the mare. Apollo 16 soil samples from stations selected to collect either Descartes Mountains material or Cayley Plains material were surprisingly similar. However, they do, indeed, show the chemical trends indicative of the two units as defined by the orbiting geochemistry detectors. The Kant Plateau and Descartes Mountains material may be among the rare nearside examples of a plagioclase-rich cumulate of the primordial magma ocean.

  14. A Younger Dryas plateau icefield in the Monadhliath, Scotland, and implications for regional palaeoclimate

    Science.gov (United States)

    Boston, Clare M.; Lukas, Sven; Carr, Simon J.

    2015-01-01

    A record of Younger Dryas glaciation in Scotland is well established. However, the role of the Monadhliath, a significant plateau area extending over 840 km2 in central Scotland, has never been investigated systematically. We present the first systematic glacial geomorphological mapping across the whole region, which has led to the identification of hitherto-unrecorded glacial and associated landforms. The spatial distribution of these landforms indicates that the last phase of glaciation in the area was that of a local plateau icefield. In addition, a clear morphostratigraphical signature provides a strong indication that the icefield dates to the Younger Dryas (12.9-11.7 ka), which is supported by numerical ages in the southeast of the study area. Based on the geomorphological evidence and 2D glacier surface profile modelling, a 280 km2 icefield is reconstructed. A novel approach is introduced to quantify plateau icefield thickness for equilibrium line altitude (ELA) and palaeoprecipitation calculations, resulting in greater overall data confidence compared to traditional reconstruction methods. The ELA for the whole icefield is calculated to be 714 ± 25 m, whilst the ELAs of individual outlet glaciers range from 560 m in the west to 816 m in the east, demonstrating a significant W-E precipitation gradient across the region during the Younger Dryas. These ELAs compare well with those calculated for Younger Dryas ice masses reconstructed in neighbouring regions and are in good agreement with overall precipitation patterns suggested for Scotland during this time. Whilst the total amount of precipitation calculated from these ELAs is highly dependent on the method used, irrespective of this, the study suggests a more arid Younger Dryas climate in the region compared to the present day.

  15. Numerical simulation of groundwater flow in the Columbia Plateau Regional Aquifer System, Idaho, Oregon, and Washington

    Science.gov (United States)

    Ely, D. Matthew; Burns, Erick R.; Morgan, David S.; Vaccaro, John J.

    2014-01-01

    A three-dimensional numerical model of groundwater flow was constructed for the Columbia Plateau Regional Aquifer System (CPRAS), Idaho, Oregon, and Washington, to evaluate and test the conceptual model of the system and to evaluate groundwater availability. The model described in this report can be used as a tool by water-resource managers and other stakeholders to quantitatively evaluate proposed alternative management strategies and assess the long‑term availability of groundwater. The numerical simulation of groundwater flow in the CPRAS was completed with support from the Groundwater Resources Program of the U.S. Geological Survey Office of Groundwater.

  16. Similar Ring Structures on Mars and Tibetan Plateau confirm recent tectonism on Martian Northern polar region

    Science.gov (United States)

    Anglés, A.; Li, Y. L.

    2017-10-01

    The polar regions of Mars feature layered deposits, some of which exist as enclosed zoning structures. These deposits raised strong interest since their discovery and still remain one of the most controversial features on Mars. Zoning structures that are enclosed only appear in the Northern polar region, where the disappearance of water bodies may have left behind huge deposits of evaporate salts. The origin of the layered deposits has been widely debated. Here we propose that the enclosed nature of the zoning structures indicates the result of recent tectonism. We compared similar structures at an analogue site located in the western Qaidam Basin of Tibetan Plateau, a unique tectonic setting with abundant saline deposits. The enclosed structures, which we term Ring Structures, in both the analogue site and in the Northern polar region of Mars, were formed by uplift induced pressurization and buoyancy of salts as the result of recent tectonic activity.

  17. Deformation and Plateau Region of Functionally Graded Aluminum Foam by Amount Combinations of Added Blowing Agent.

    Science.gov (United States)

    Hangai, Yoshihiko; Utsunomiya, Takao; Kuwazuru, Osamu; Kitahara, Soichiro; Yoshikawa, Nobuhiro

    2015-10-21

    Recently, to further improve the performance of aluminum foam, functionally graded (FG) aluminum foams, whose pore structure varies with their position, have been developed. In this study, three types of FG aluminum foam of aluminum alloy die casting ADC12 with combinations of two different amounts of added blowing agent titanium(II) hydride (TiH₂) powder were fabricated by a friction stir welding (FSW) route precursor foaming method. The combinations of 1.0-0 mass %, 0.4-0 mass %, and 0.2-0 mass % TiH₂ were selected as the amounts of TiH₂ relative to the mass of the volume stirred by FSW. The static compression tests of the fabricated FG aluminum foams were carried out. The deformation and fracture of FG aluminum foams fundamentally started in the high-porosity (with TiH₂ addition) layer and shifted to the low-porosity (without TiH₂ addition) layer. The first and second plateau regions in the relationship between compressive stress and strain independently appeared with the occurrence of deformations and fractures in the high- and low-porosity layers. It was shown that FG aluminum foams, whose plateau region varies in steps by the combination of amounts of added TiH₂ ( i.e. , the combination of pore structures), can be fabricated.

  18. Deformation and Plateau Region of Functionally Graded Aluminum Foam by Amount Combinations of Added Blowing Agent

    Directory of Open Access Journals (Sweden)

    Yoshihiko Hangai

    2015-10-01

    Full Text Available Recently, to further improve the performance of aluminum foam, functionally graded (FG aluminum foams, whose pore structure varies with their position, have been developed. In this study, three types of FG aluminum foam of aluminum alloy die casting ADC12 with combinations of two different amounts of added blowing agent titanium(II hydride (TiH2 powder were fabricated by a friction stir welding (FSW route precursor foaming method. The combinations of 1.0–0 mass %, 0.4–0 mass %, and 0.2–0 mass % TiH2 were selected as the amounts of TiH2 relative to the mass of the volume stirred by FSW. The static compression tests of the fabricated FG aluminum foams were carried out. The deformation and fracture of FG aluminum foams fundamentally started in the high-porosity (with TiH2 addition layer and shifted to the low-porosity (without TiH2 addition layer. The first and second plateau regions in the relationship between compressive stress and strain independently appeared with the occurrence of deformations and fractures in the high- and low-porosity layers. It was shown that FG aluminum foams, whose plateau region varies in steps by the combination of amounts of added TiH2 (i.e., the combination of pore structures, can be fabricated.

  19. Deformation and Plateau Region of Functionally Graded Aluminum Foam by Amount Combinations of Added Blowing Agent

    Science.gov (United States)

    Hangai, Yoshihiko; Utsunomiya, Takao; Kuwazuru, Osamu; Kitahara, Soichiro; Yoshikawa, Nobuhiro

    2015-01-01

    Recently, to further improve the performance of aluminum foam, functionally graded (FG) aluminum foams, whose pore structure varies with their position, have been developed. In this study, three types of FG aluminum foam of aluminum alloy die casting ADC12 with combinations of two different amounts of added blowing agent titanium(II) hydride (TiH2) powder were fabricated by a friction stir welding (FSW) route precursor foaming method. The combinations of 1.0–0 mass %, 0.4–0 mass %, and 0.2–0 mass % TiH2 were selected as the amounts of TiH2 relative to the mass of the volume stirred by FSW. The static compression tests of the fabricated FG aluminum foams were carried out. The deformation and fracture of FG aluminum foams fundamentally started in the high-porosity (with TiH2 addition) layer and shifted to the low-porosity (without TiH2 addition) layer. The first and second plateau regions in the relationship between compressive stress and strain independently appeared with the occurrence of deformations and fractures in the high- and low-porosity layers. It was shown that FG aluminum foams, whose plateau region varies in steps by the combination of amounts of added TiH2 (i.e., the combination of pore structures), can be fabricated. PMID:28793626

  20. Determination of snow cover from MODIS data for the Tibetan Plateau region

    Science.gov (United States)

    Tang, Bo-Hui; Shrestha, Basanta; Li, Zhao-Liang; Liu, Gaohuan; Ouyang, Hua; Gurung, Deo Raj; Giriraj, Amarnath; Aung, Khun San

    2013-04-01

    This paper addresses a snow-mapping algorithm for the Tibetan Plateau region using Moderate Resolution Imaging Spectroradiometer (MODIS) data. Accounting for the effects of the atmosphere and terrain on the satellite observations at the top of the atmosphere (TOA), particularly in the rugged Tibetan Plateau region, the surface reflectance is retrieved from the TOA reflectance after atmospheric and topographic corrections. To reduce the effect of the misclassification of snow and cloud cover, a normalized difference cloud index (NDCI) model is proposed to discriminate snow/cloud pixels, separate from the MODIS cloud mask product MOD35. The MODIS land surface temperature (LST) product MOD11_L2 is also used to ensure better accuracy of the snow cover classification. Comparisons of the resulting snow cover with those estimated from high spatial-resolution Landsat ETM+ data and obtained from MODIS snow cover product MOD10_L2 for the Mount Everest region for different seasons in 2002, show that the MODIS snow cover product MOD10_L2 overestimates the snow cover with relative error ranging from 20.1% to 55.7%, whereas the proposed algorithm estimates the snow cover more accurately with relative error varying from 0.3% to 9.8%. Comparisons of the snow cover estimated with the proposed algorithm and those obtained from MOD10_L2 product with in situ measurements over the Hindu Kush-Himalayan (HKH) region for December 2003 and January 2004 (the snowy seasons) indicate that the proposed algorithm can map the snow cover more accurately with greater than 90% agreement.

  1. Prediction of Bulk Density of Soils in the Loess Plateau Region of China

    Science.gov (United States)

    Wang, Yunqiang; Shao, Ming'an; Liu, Zhipeng; Zhang, Chencheng

    2013-08-01

    Soil bulk density (BD) is a key soil physical property that may affect the transport of water and solutes and is essential to estimate soil carbon/nutrients reserves. However, BD data are often lacking in soil databases due to the challenge of directly measuring BD, which is considered to be labor intensive, time consuming, and expensive especially for the lower layers of deep soils such as those of the Chinese Loess Plateau region. We determined the factors that were closely correlated with BD at the regional scale and developed a robust pedotransfer function (PTF) for BD by measuring BD and potentially related soil and environmental factors at 748 selected sites across the Loess Plateau of China (620,000 km2) at which we collected undisturbed and disturbed soil samples from two soil layers (0-5 and 20-25 cm). Regional BD values were normally distributed and demonstrated weak spatial variation (CV = 12 %). Pearson's correlation and stepwise multiple linear regression analyses identified silt content, slope gradient (SG), soil organic carbon content (SOC), clay content, slope aspect (SA), and altitude as the factors that were closely correlated with BD and that explained 25.8, 6.3, 5.8, 1.4, 0.3, and 0.3 % of the BD variation, respectively. Based on these closely correlated variables, a reasonably robust PTF was developed for BD using multiple linear regression, which performed equally with the artificial neural network method in the current study. The inclusion of topographic factors significantly improved the predictive capability of the BD PTF and in which SG was an important input variable that could be used in place of SA and altitude without compromising its capability for predicting BD. Thus, the developed PTF with only four input variables (clay, silt, SOC, SG), including their common transformations and interactive terms, predicted BD with reasonable accuracy and is thus useful for most applications on the Loess Plateau of China. More attention should be

  2. Regional effects of vegetation restoration on water yield across the Loess Plateau, China

    Directory of Open Access Journals (Sweden)

    X. M. Feng

    2012-08-01

    Full Text Available The general relationships between vegetation and water yield under different climatic regimes are well established at a small watershed scale in the past century. However, applications of these basic theories to evaluate the regional effects of land cover change on water resources remain challenging due to the complex interactions of vegetation and climatic variability and hydrologic processes at the large scale. The objective of this study was to explore ways to examine the spatial and temporal effects of a large ecological restoration project on water yield across the Loess Plateau region in northern China. We estimated annual water yield as the difference between precipitation input and modelled actual evapotranspiration (ET output. We constructed a monthly ET model using published ET data derived from eddy flux measurements and watershed streamflow data. We validated the ET models at a watershed and regional levels. The model was then applied to examine regional water yield under land cover change and climatic variability during the implementation of the Grain-for-Green (GFG project during 1999–2007. We found that water yield in 38% of the Loess Plateau area might have decreased (1–48 mm per year as a result of land cover change alone. However, combined with climatic variability, 37% of the study area might have seen a decrease in water yield with a range of 1–54 mm per year, and 35% of the study area might have seen an increase with a range of 1–10 mm per year. Across the study region, climate variability masked or strengthened the water yield response to vegetation restoration. The absolute annual water yield change due to vegetation restoration varied with precipitation regimes with the highest in wet years, but the relative water yield changes were most pronounced in dry years. We concluded that the effects of land cover change associated with ecological restoration varied greatly over time and space and were strongly influenced

  3. Carbonaceous matter deposition in the high glacial regions of the Tibetan Plateau

    Science.gov (United States)

    Li, C.; Pengfei, C.; Shichang, K.; Fangping, Y.; Li, X.; Qu, B.; Sillanpää, M.

    2016-12-01

    Carbonaceous matter at glacial region plays important role in river ecosystems fed by glacier and albedo reduction of glacier surface. However, currently, limited knowledge are available on the carbonaceous matter within the glacial region of the Tibetan Plateau (TP). In this study, the data from six snowpits in the glacial region across the TP were reported. The results showed that dissolved organic carbon (DOC) concentrations of snowpit samples of the TP were comparable to those of European Alps and the Arctic. The ratio of DOC to carbonaceous matter (40.25±8.98%) was lower than that of Alpine glaciers, thus indicating greater particulate carbon content in the TP glacial region. In addition, the DOC was significantly correlated with insoluble particulate carbon (IPC), indicating that IPC and DOC likely came from the same sources. Spatially, the DOC concentration decreased from the north (0.42±0.29 mg-C L-1) to the south TP (0.15±0.06 mg-C L-1), which was consistent with variations in the distribution of dust storm on the TP. Principal component analysis of major ions and DOC showed that mineral dust contributed the major part of DOC, followed by biogenic sources such as agriculture and livestock. Finally, based on DOC concentrations and precipitation amounts at different periods, the mean annul flux of DOC in the glacial region of the TP was calculated to be 0.11±0.05 g-C m-2 yr-1.

  4. Trends of temperature and precipitation extremes in the Loess Plateau Region of China, 1961-2010

    Science.gov (United States)

    Wang, Qi-xiang; Wang, Meng-ben; Fan, Xiao-hui; Zhang, Feng; Zhu, Shi-zhong; Zhao, Tian-liang

    2017-08-01

    The spatial and temporal trends of 11 (7) temperature (precipitation) extreme indices are examined for the Loess Plateau Region (LPR) and its southeast and northwest sub-regions based on daily observations at 214 meteorological stations. Results show widespread significant warming trends for all the temperature extremes except for the diurnal temperature range (DTR) and the lowest daily maximum temperature in each year (TXn) during 1961-2010. When regionally averaged, a significant warming trend is detected for all the indices except for DTR and TXn in the past 50 years. Compared with the entire LPR, a significant warming trend is detected for all the indices except for DTR and TXn over the southeast sub-region of LPR; while it is observed for all the indices over the northwest. The trends for these indices are generally stronger in the northwest than in the southeast in the past 50 years. In contrast, for precipitation indices, only a small percentage of areas show significant drying or wetting trends and, when regionally averaged, none of them displays significant trends during the past 50 years. On the sub-regional scale, however, a larger percentage of areas show significant drying trends for precipitation indices generally over the southeast relative to the entire LPR, and noticeably, the sub-regional average heavy precipitation (R10mm) and wet day precipitation (PRCPTOT) display significant decreasing trends during the past 50 years; whereas only a slightly larger percentage of areas show significant wetting trends for these indices over the northwest compared with the entire LPR, and when sub-regionally averaged, none of the indices have significant trends during the past 50 years.

  5. Influences of subtropical jet and Tibetan Plateau on precipitation pattern in Asia : Insights from regional climate modeling

    NARCIS (Netherlands)

    Sato, Tomonori

    2009-01-01

    Large topographic features, like the Tibetan Plateau (TP) and the Rocky Mountains, have significant impacts on Earth's climate. Numerical experiments were carried out using a regional climate model in order to study the sensitivity of rainfall distribution to the TP's thermal/dynamic effects and

  6. The impacts of precipitation on land- atmosphere interaction over the semi-arid Loess Plateau region

    Science.gov (United States)

    WANG, G.; Huang, J.

    2015-12-01

    To understand the impacts of precipitation on land-atmosphere interactions over semi-arid regions, 6-year continuous measurements data in situ were analyzed to investigate the influence of precipitation on soil moisture, evapotranspiration, energy partitioning and plant growing over Loess Plateau in northwest China. Results show that annual precipitation had obvious inter-annual variability, and the variation of soil moisture; evaporation and CO2 flux were very consistently with the annual cycle and intensity of precipitation. Soil moisture is the key participant in land-atmosphere interaction. However, as the water shortage and disconnected from water table over the semi-arid region, it is much more sensitive with precipitation compensation and evaporation feedbacks. Soil water can cooling the near surface air temperature by evaporation (latent heat flux), and also as the main energy partitioning consumer of net radiation in humid area or pluvial period in arid area, yet it was water limited in arid and semi-arid region, sensible heat flux predominated net radiation for enhancing the surface air temperature. We also found that soil moisture profile significantly affected the plant physiology, which was also consistent with the annual cycle and intensity of precipitation.

  7. Quantitative Assessment of Desertification Using Landsat Data on a Regional Scale – A Case Study in the Ordos Plateau, China

    Directory of Open Access Journals (Sweden)

    Jianjun Pan

    2009-03-01

    Full Text Available Desertification is a serious threat to the ecological environment and social economy in our world and there is a pressing need to develop a reasonable and reproducible method to assess it at different scales. In this paper, the Ordos Plateau in China was selected as the research region and a quantitative method for desertification assessment was developed by using Landsat MSS and TM/ETM+ data on a regional scale. In this method, NDVI, MSDI and land surface albedo were selected as assessment indicators of desertification to represent land surface conditions from vegetation biomass, landscape pattern and micrometeorology. Based on considering the effects of vegetation type and time of images acquired on assessment indictors, assessing rule sets were built and a decision tree approach was used to assess desertification of Ordos Plateau in 1980, 1990 and 2000. The average overall accuracy of three periods was higher than 90%. The results showed that although some local places of Ordos Plateau experienced an expanding trend of desertification, the trend of desertification of Ordos Plateau was an overall decrease in from 1980 to 2000. By analyzing the causes of desertification processes, it was found that climate change could benefit for the reversion of desertification from 1980 to 1990 at a regional scale and human activities might explain the expansion of desertification in this period; however human conservation activities were the main driving factor that induced the reversion of desertification from 1990 to 2000.

  8. Quantitative Assessment of Desertification Using Landsat Data on a Regional Scale – A Case Study in the Ordos Plateau, China

    Science.gov (United States)

    Xu, Duanyang; Kang, Xiangwu; Qiu, Dongsheng; Zhuang, Dafang; Pan, Jianjun

    2009-01-01

    Desertification is a serious threat to the ecological environment and social economy in our world and there is a pressing need to develop a reasonable and reproducible method to assess it at different scales. In this paper, the Ordos Plateau in China was selected as the research region and a quantitative method for desertification assessment was developed by using Landsat MSS and TM/ETM+ data on a regional scale. In this method, NDVI, MSDI and land surface albedo were selected as assessment indicators of desertification to represent land surface conditions from vegetation biomass, landscape pattern and micrometeorology. Based on considering the effects of vegetation type and time of images acquired on assessment indictors, assessing rule sets were built and a decision tree approach was used to assess desertification of Ordos Plateau in 1980, 1990 and 2000. The average overall accuracy of three periods was higher than 90%. The results showed that although some local places of Ordos Plateau experienced an expanding trend of desertification, the trend of desertification of Ordos Plateau was an overall decrease in from 1980 to 2000. By analyzing the causes of desertification processes, it was found that climate change could benefit for the reversion of desertification from 1980 to 1990 at a regional scale and human activities might explain the expansion of desertification in this period; however human conservation activities were the main driving factor that induced the reversion of desertification from 1990 to 2000. PMID:22573984

  9. Groundwater availability of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    Vaccaro, J.J.; Kahle, S.C.; Ely, D.M.; Burns, E.R.; Snyder, D.T.; Haynes, J.V.; Olsen, T.D.; Welch, W.B.; Morgan, D.S.

    2015-09-22

    The Columbia Plateau Regional Aquifer System (CPRAS) covers about 44,000 square miles of southeastern Washington, northeastern Oregon, and western Idaho. The area supports a $6-billion per year agricultural industry, leading the Nation in production of apples, hops, and eight other commodities. Groundwater pumpage and surface-water diversions supply water to croplands that account for about 5 percent of the Nation’s irrigated lands. Groundwater also is the primary source of drinking water for the more than 1.3 million people in the study area. Increasing competitive demands for water for municipal, fisheries/ecosystems, agricultural, domestic, hydropower, and recreational uses must be met by additional groundwater withdrawals and (or) by changes in the way water resources are allocated and used throughout the hydrologic system. As of 2014, most surface-water resources in the study area were either over allocated or fully appropriated, especially during the dry summer season. In response to continued competition for water, numerous water-management activities and concerns have gained prominence: water conservation, conjunctive use, artificial recharge, hydrologic implications of land-use change, pumpage effects on streamflow, and effects of climate variability and change. An integrated understanding of the hydrologic system is important in order to implement effective water-resource management strategies that address these concerns.

  10. Surface Mining and Reclamation Effects on Flood Response of Watersheds in the Central Appalachian Plateau Region

    Science.gov (United States)

    Ferrari, J. R.; Lookingbill, T. R.; McCormick, B.; Townsend, P. A.; Eshleman, K. N.

    2009-01-01

    Surface mining of coal and subsequent reclamation represent the dominant land use change in the central Appalachian Plateau (CAP) region of the United States. Hydrologic impacts of surface mining have been studied at the plot scale, but effects at broader scales have not been explored adequately. Broad-scale classification of reclaimed sites is difficult because standing vegetation makes them nearly indistinguishable from alternate land uses. We used a land cover data set that accurately maps surface mines for a 187-km2 watershed within the CAP. These land cover data, as well as plot-level data from within the watershed, are used with HSPF (Hydrologic Simulation Program-Fortran) to estimate changes in flood response as a function of increased mining. Results show that the rate at which flood magnitude increases due to increased mining is linear, with greater rates observed for less frequent return intervals. These findings indicate that mine reclamation leaves the landscape in a condition more similar to urban areas rather than does simple deforestation, and call into question the effectiveness of reclamation in terms of returning mined areas to the hydrological state that existed before mining.

  11. Water use pattern of Pinus tabulaeformis in the semiarid region of Loess Plateau, China

    Energy Technology Data Exchange (ETDEWEB)

    Jian, S.; Zhang, X.; Wu, Z.; Hu, C.

    2016-07-01

    Aim of the study: We analyzed the water-use strategy of P. tabulaeformis and determine the relationships between environmental factors and transpiration rates in the P. tabulaeformis woodlands. Area of study: Loess Plateau region of Northwest China. Material and Methods: Sap flow density of the P. tabulaeformis trees was measured with Granier-type sensors. Stand transpiration was extrapolated from the sap flow measurements of individual trees using the following Granier equation. Main results: The mean sap flow rates of individual P. tabulaeformis trees ranged from 9 L day−1 to 54 L day−1. Photosynthetically active radiation and vapor pressure deficit were the dominant driving factors of transpiration when soil water content was sufficient (soil water content>16%), considering that soil water content is the primary factor of influencing transpiration at the driest month of the year. During the entire growing season, the maximum and minimum daily stand transpiration rates were 2.93 and 0.78 mm day−1, respectively. The mean stand transpiration rate was 1.9 mm day−1, and the total stand transpiration from May to September was 294.1 mm. Research highlights: This study can serve as a basis for detailed analyses of the water physiology and growth of P. tabulaeformis plantation trees for the later application of a climate-driven process model. (Author)

  12. [Dynamic changes of Robinia pseudoacacia sap flow in hilly-gully region of Loess Plateau].

    Science.gov (United States)

    Hu, Wei; Du, Feng; Xu, Xue-Xuan; Zhang, Liang-De

    2010-06-01

    From April 14 to October 10, 2009, the dynamic changes of Robinia pseudoacacia sap flow in the hilly-gully region of Loess Plateau were measured with thermal dissipation probe. Meantime, the photosynthetic active radiation (PAR), air temperature, relative air humidity, water vapor pressure deficit (VPD), wind speed, and rainfall were monitored. The diurnal variation of the sap flow velocity (SFV) displayed a single-peak curve, but the pattern varied among different months. In April, the sap flow started to increase at about 12:00, and reached the peak at about 18:00. From May to August, the sap flow started to increase at 5:30-7:30, and reached the peak at about 15:00. In September and October, the sap flow started to increase at about 8:00, and reached the peak at 11:30-13:00. The monthly average SFV was the highest in August and the lowest in April, with the value being 0.002610 cm x s(-1) and 0.000549 cm x s(-1), respectively. During the monitoring period, the sap flow velocity was significantly correlated with PAR, air temperature, VPD, wind speed, and air relative humidity, and the correlation coefficients declined in the order of air temperature > VPD > PAR > relative humidity > wind speed. The sap flow velocity could be estimated by the linear equation with variables PAR and VPD, and the regression coefficients were highly significant.

  13. Surface Deformation Monitoring in Permafrost Regions of Tibetan Plateau Based on Alos Palsar Data

    Science.gov (United States)

    Chen, L. M.; Qiao, G.; Lu, P.

    2017-09-01

    The permafrost region of Qinghai-Tibet Plateau is widely distributed with the freeze/thaw processes that cause surface structural damage. The differential interferometry synthetic aperture radar (DInSAR) can detect large scale surface deformation with high precision, thus can be used to monitor the freeze/thaw processes of frozen soil area. In this paper, the surface deformation pattern of Qinghai-Tibet railway was analyzed by using the PALSAR 1.0 raw data of the ALOS satellite (L band) and 90m resolution SRTM DEM data, with the help of two-pass DInSAR method in GAMMA software, and the differential interferograms and deformation maps were obtained accordingly. Besides, the influence of temperature, topography and other factors on deformation of frozen soil were also studied. The following conclusions were obtained: there is a negative correlation between deformation and temperature, and there is a delay between the deformation change and that of temperature; deformation and elevation are positively correlated; the permafrost deformation is also affected by solar radiation that could form variable amplitude variation.

  14. Physiological responses of Kobresia pygmaea to warming in Qinghai-Tibetan Plateau permafrost region

    Science.gov (United States)

    Yang, Y.; Wang, G. X.; Yang, L. D.; Guo, J. Y.; Li, N.

    2012-02-01

    Kobresia pygmaea (C. B. Clarke) C. B. Clarke is one dominant herbaceous species in the alpine meadows of the Qinghai-Tibetan Plateau. From 2006 to 2009, a warming experiment was conducted in this permafrost region. Two 2-year warming treatments with an annual average warming of 2.1 °C and 4.4 °C, and one 4-year warming treatment with an annual average warming of 2.3 °C were established to examine physiological responses of K. pygmaea to warming. Our results indicated that 2-years of warming increased malondialdehyde and non-structural carbohydrates in the plants. There was no effect of 2-year warming on electrolyte leakage and free proline content. In the 2-year warming treatment, superoxide dismutase activity and peroxidase activity increased, ascorbate peroxidase activity and ascorbic acid only increased in 2-year high warming treatment, whereas in the 4-year warming treatment, active oxygen species, electrolyte leakage, UV-absorbing compounds and anthocyanins decreased. The 4-year warming treatment also significantly increased non-structural carbonhydrate and free proline accumulation for osmotic adjustment. The results of this study suggest that K. pygmaea could adapt to a warmer environment in the future.

  15. Reconstructed 2.5-Degree Monthly Precipitation Data for the Tibetan Plateau Region Since 1901

    Science.gov (United States)

    Shen, S. S.

    2015-12-01

    This presentation describes a monthly 2.5-by-2.5 lat-lon Tibetan Plateau (TP) region's precipitation data product since January 1901, reconstructed by a multivariate regression method using an empirical orthogonal function (EOF) expansion. The Global Precipitation Climatology Project (GPCP) precipitation data from 1981-2010 are used to calculate the EOFs. The Global Historical Climatology Network (GHCN) gridded data are used to calculate the regression coefficients for reconstructions. The sampling errors of the reconstruction are analyzed in detail for different number of EOF modes used in the reconstruction. The spatial average time series of the reconstructed TP precipitation from 1910-2001 has a small positive trend: 0.006 (mm/day)/100a. This positive trend is consistent with other studies based on the observed data from 71 TP stations from 1961-2001, in contrast to the negative trends in the reanalysis data from 1961-2001 from both the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) and the European Centre for Medium-Range Weather Forecasts (ERA-40). The validation of our reconstruction data with GPCP from 1979-present makes it reliable to use this reconstruction dataset as the benchmark data for TP precipitation models. Our reconstructed TP precipitation for over 100 years will help the climate modeling community to improve TP precipitation mechanisms, reduce the systematic difference between the data from observations and climate models, and analyze the interdecadal variations of the TP climate. Our TP precipitation product is publically available online, including digital data, precipitation animations, computer codes, readme files, and the user manual. This work is a joint effort between San Diego State University (Sam Shen, Nancy Tafolla, Gregori Clarke, Greg Behm, Barbara Sperberg, and Melanie Thorn), Institute of Tibetan Plateau Research, Chinese Academy of Sciences (Tandong Yao, and Jing Gao), and

  16. 77 FR 1717 - Notice of Availability; Draft Springfield Plateau Regional Restoration Plan and Environmental...

    Science.gov (United States)

    2012-01-11

    ... Environmental Assessment (Plan), which describes proposed alternatives for restoring injured natural resources in the Springfield Plateau ecoregion, and an environmental assessment, as required pursuant to the... Resource Damage Assessment and Restoration (NRDAR) regulations and NEPA regulations. DATES: To ensure...

  17. Regionalization of land surface heat fluxes and evapotranspiration over heterogeneous landscape: from Tibetan Plateau to Third Pole region and Pan-Third Pole region

    Science.gov (United States)

    Ma, Yaoming

    2017-04-01

    The exchange of heat and water vapor between land surface and atmosphere over the Third Pole region (Tibetan Plateau and surrounding region) and Pan-Third Pole region (Third Pole region and surrounding region) play an important role in the Asian monsoon, westerlies and the northern hemisphere weather systems. Supported by the Chinese Academy of Sciences and some international organizations, a Third Pole Environment (TPE) Research Platform (TPEP) and Pan-TPE Research Platform (PTPEP) are now implementing over the Third Pole region and Pan-Third Pole region. The background of the establishment of the TPEP and PTPEP, the establishing and monitoring plan of long-term scale (5-10 years) of the TPEP and PTPEP will be shown firstly. Then the preliminary observational analysis results, such as the characteristics of land surface heat fluxes partitioning, the characteristics of atmospheric and soil variables, the structure of the Atmospheric Boundary Layer (ABL) and the turbulent characteristics have also been shown in this study. The parameterization method based on satellite data and the ABL observations has been proposed and tested for deriving regional distribution of surface reflectance, surface temperature, net radiation flux, soil heat flux, sensible heat flux, latent heat flux and evapotranspiration (ET) over heterogeneous landscape. As cases study, the method was applied to the whole Tibetan Plateau area and Nepal area. To validate the proposed method, the ground-measured surface reflectance, surface temperature, net radiation flux, soil heat flux, sensible heat flux and latent heat flux in the TPEP are compared to the derived values. The results show that the derived surface variables, land surface heat fluxes and ET over the study area are in good accordance with the land surface status. These parameters show a wide range due to the strong contrast of surface features. And the estimated land surface variables and land surface heat fluxes are in good agreement

  18. Attribution analysis of runoff decline in a semiarid region of the Loess Plateau, China

    Science.gov (United States)

    Li, Binquan; Liang, Zhongmin; Zhang, Jianyun; Wang, Guoqing; Zhao, Weimin; Zhang, Hongyue; Wang, Jun; Hu, Yiming

    2018-01-01

    runoff decline. This study enhances our understanding of runoff changes caused by SWC measures and climate variability in the typical semiarid region of Loess Plateau, China.

  19. Geologic Setting and Hydrogeologic Units of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    Kahle, Sue C.; Olsen, Theresa D.; Morgan, David S.

    2009-01-01

    The Columbia Plateau Regional Aquifer System (CPRAS) covers approximately 44,000 square miles of northeastern Oregon, southeastern Washington, and western Idaho. The area supports a $6 billion per year agricultural industry, leading the Nation in production of apples and nine other commodities (State of Washington Office of Financial Management, 2007; U.S. Department of Agriculture, 2007). Groundwater availability in the aquifers of the area is a critical water-resource management issue because the water demand for agriculture, economic development, and ecological needs is high. The primary aquifers of the CPRAS are basalts of the Columbia River Basalt Group (CRBG) and overlying basin-fill sediments. Water-resources issues that have implications for future groundwater availability in the region include (1) widespread water-level declines associated with development of groundwater resources for irrigation and other uses, (2) reduction in base flow to rivers and associated effects on temperature and water quality, and (3) current and anticipated effects of global climate change on recharge, base flow, and ultimately, groundwater availability. As part of a National Groundwater Resources Program, the U.S. Geological Survey began a study of the CPRAS in 2007 with the broad goals of (1) characterizing the hydrologic status of the system, (2) identifying trends in groundwater storage and use, and (3) quantifying groundwater availability. The study approach includes documenting changes in the status of the system, quantifying the hydrologic budget for the system, updating the regional hydrogeologic framework, and developing a groundwater-flow simulation model for the system. The simulation model will be used to evaluate and test the conceptual model of the system and later to evaluate groundwater availability under alternative development and climate scenarios. The objectives of this study were to update the hydrogeologic framework for the CPRAS using the available

  20. Differences in mass balance behavior for three glaciers from different climatic regions on the Tibetan Plateau

    Science.gov (United States)

    Zhu, Meilin; Yao, Tandong; Yang, Wei; Xu, Baiqing; Wu, Guanjian; Wang, Xiaojun

    2017-07-01

    Glacier mass balance shows a spatially heterogeneous pattern in response to global warming on the Tibetan Plateau (TP), and the climate mechanisms controlling this pattern require further study. In this study, three glaciers where systematic glaciological and meteorological observations have been carried out were selected, specifically Parlung No. 4 (PL04) and Zhadang (ZD) glaciers on the southern TP and Muztag Ata No. 15 (MZ15) glacier in the eastern Pamir. The characteristics of the mass and energy balances of these three glaciers during the periods between October 1th, 2008 and September 23rd, 2013 were analyzed and compared using the energy and mass balance model. Results show that differences in surface melt, which mainly result from differences in the amounts of incoming longwave radiation (L in ) and outgoing shortwave radiation (S out ), represent the largest source of the observed differences in mass balance changes between PL04 and ZD glaciers and MZ15 glacier, where air temperature, humidity, precipitation and cloudiness are dramatically different. In addition, sensitivity experiments show that mass balance sensitivity to air temperature change is remarkably higher than that associated with precipitation change on PL04 and ZD glaciers, in contrast results from MZ15 glacier. And significantly higher sensitivities to air temperature change are noted for PL04 and ZD glaciers than for MZ15 glacier. These significant differences in the sensitivities to air temperature change are mainly caused by differences in the ratio of snowfall to precipitation during the ablation season, melt energy (L in +S out ) during the ablation season and the seasonality of precipitation among the different regions occupied by glaciers. In turn, these conditions are related to local climatic conditions, especially air temperature. These factors can be used to explain the different patterns of change in Tibetan glacier mass balance under global warming.

  1. [Genotyping by CRISPR and regional distribution of Yersinia pestis in Qinghai-plateau from 1954 to 2011].

    Science.gov (United States)

    Xu, X Q; Xin, Y Q; Li, X; Zhang, Q W; Yang, X Y; Jin, Y; Zhao, H H; Jin, X; Qi, Z Z

    2017-03-06

    Objective: To investigate the CRISPR genotypes (clusters) and regional distribution of Yersinia pestis in Qinghai-plateau. Methods: One hundred and two isolates of Y. pestis isolated from human plague patients, host animal and insect vectors from Qinghai-plateau were selected. The DNAs were extracted using the traditional sodium dodecyl sulfate decomposition and phenol-chloroform method. Three CRISPR loci YPa, YPb and YPc of 102 isolates of Y. pesits were amplified and sequenced, and then the CRISPR sequence analysis was carried out by comparing the latest published CRISPR spacer dictionary and the NCBI database to identify the spacer and spacer array. CRISPR genotyping of isolates of Y. pesits were finally conducted according to the polymorphism of the spacer arrays and the regional distribution pattern of isolates of Y. pesits in Qinghai-plateau was described. Results: Forty spacers including 22 of YPa, 13 of YPb and 5 of YPc were observed among 102 isolates of Y. pestis in Qinghai-plateau, of which 5 spacers (a1', a103, a104, b4'' and b4''') were firstly identified. Meanwhile, 16, 10, and 5 different spacer arrays were obtained in YPa, YPb and YPc respectively, including 11 new spacer arrays detected in this study. One hundred and two isolates were divided into 24 CRISPR genotypes and classified into 9 CRISPR clusters (Cb4, Cb4', Cb2, Ca37, Ca7, Ca7', CaΔ5', Ca35' and Cc3'). Each dominant cluster presented significant aggregation geographically: Ca7 were found in Yushu, Nangqian, Chenduo, Zaduo, Zhiduo and Qumalai countries. Ca7' were found in Xunhua, Tongren, Zeku, Tongde, Maqin and Guinan countries. CaΔ5' were restricted to Qilian, Gangcha, Menyuan and Datong countries. CaΔ35' were found in Huangyuan, Haiyan, Gangcha, Tianjun, Delingha, Wulan, Doulan, Gonghe, Xinghai, Guide and Tongde countries. Conclusion: CRISPR-based genotyping analyses showed complicated population of Y. pestis in Qinghai-plateau. Four clusters, Ca7, Ca7', CaΔ5' and Ca35' were the most

  2. Phylogeography and genetic effects of habitat fragmentation on endemic Urophysa (Ranunculaceae) in Yungui Plateau and adjacent regions.

    Science.gov (United States)

    Xie, Deng-Feng; Li, Min-Jie; Tan, Jin-Bo; Price, Megan; Xiao, Qun-Ying; Zhou, Song-Dong; Yu, Yan; He, Xing-Jin

    2017-01-01

    Urophysa is a Chinese endemic genus with only two species (U. rockii and U. henryi) distributed in Yungui Plateau (Guizhou Province) and adjacent regions (i.e., Provinces of Hunan, Hubei, Chongqing and Sichuan). The aim of this study was to determine the genetic diversity and population differentiation within Urophysa and investigate the effect of the Yungui Plateau uplift and climate oscillations on evolution of Urophysa. In this study, micro-morphological characteristics, nine microsatellite loci (SSR), two nuclear loci (ITS and ETS) and two chloroplast fragments (psbA-trnH and trnL-trnF) were used to analyze the phylogenetic relationships and assess genetic and phylogeographical structure of Urophysa. Isolation by distance (IBD) was performed to research the effects of geographical isolation. We detected high genetic diversity at the species level but low genetic diversity within populations. Striking genetic differentiation (AMOVA) among populations and a significant phylogeographical structure (NST > GST, p habitat fragmentation played an important role in the genetic diversity and population differentiation of U. rockii and U. henryi. Heterogenous geomorphological configuration and complicated environment resulted from rapid uplift of the Yungui Plateau were inferred as important incentives for the modern phylogeograhpical pattern and species divergence of Urophysa. The geographical isolation, limited gene flow, specialized morphologies and the Pleistocene climatic oscillation greatly contributed to the allopatric divergence of U. rockii. Significant genetic drift and inbreeding were detected in these two species, in situ measures should be implemented to protect them.

  3. Surface drag over the snow surface of the Antarctic Plateau. 1. Factors controlling surface drag over the Katabatic wind region

    Science.gov (United States)

    Inoue, Jiro

    1989-02-01

    The drag coefficient of the snow surface over the Antarctic Plateau is evaluated through direct measurement of Reynolds stress on the Mizuho Plateau, East Antarctica, in the austral summer. The estimated roughness height (Z0) varies from 10-l to 10-4 cm, even under near-neutral conditions. Large shear stress appears in light wind, followed by increased turbulent intensity. In the katabatic wind region of the plateau, Z0 shows symmetric changes with wind direction. The average value of Z0 in the smoothest direction is 0.0004 cm, which is the minimum value previously reported, and it increases to 0.015 cm for 40° rotation of wind direction toward the roughest direction. The directional dependence of Z0 is similar at three stations located nearly 100 km apart. Unlike the results of Jackson and Carroll at the south pole, the smoothest direction deviates 20° from the mean sastrugi axes and agrees with the direction of the prevailing high wind. The 4-m neutral drag coefficient is estimated to be 0.8 × 10-3 for the smoothest direction and 1.5 × 10-3 for the roughest direction. The effect of snow drift is unimportant. A generalized discussion of the results is given in a companion paper.

  4. Cenozoic sediment flux in the Qaidam Basin, northern Tibetan Plateau, and implications with regional tectonics and climate

    Science.gov (United States)

    Bao, Jing; Wang, Yadong; Song, Chunhui; Feng, Ying; Hu, Chunhua; Zhong, Sirui; Yang, Jiwei

    2017-08-01

    As the largest Mesozoic-Cenozoic terrestrial intermountain basin in the northern Tibetan Plateau, the Qaidam Basin is an ideal basin to examine the influences of regional tectonics and climate on sediment flux. Research conducted over the last two decades has provided abundant information about paleoclimatology and tectonic histories. In this study, we used the restoration of seven balanced cross-sections and compiled thickness data of ten outcrop sections and four boreholes to reconstruct the basin boundaries, develop isopach maps, and calculate the sediment flux in the Qaidam Basin. Our results show that the sediment flux in the Qaidam Basin increased gradually between 53.5 and 35.5 Ma, decreased to its lowest value from 35.5 to 22 Ma, increased between 22 and 2.5 Ma, and then increased dramatically after 2.5 Ma. By comparing the changes in the sediment flux with our reconstructed shortening rate in the Qaidam Basin, and the records of regional tectonic events and regional and global climate changes, we suggest that the gradual increase in the sediment flux from 53.5 to 40.5 Ma was controlled by both the tectonic uplift of the Tibetan Plateau and the relatively warm and humid climate, and that the high sediment flux from 40.5 to 35.5 Ma was mainly controlled by tectonics. The low sediment flux from 35.5 to 22 Ma was a response to the relatively cold and arid climate in a stable tectonic setting. The relatively high sediment flux between 22 and 15.3 Ma was related to tectonic activity and the warm and humid climate. The intense tectonic uplift of the northern Tibetan Plateau and the frequent climate oscillations after 15.3 Ma, particularly the glacial-interglacial cycles after 2.5 Ma, caused the high sediment flux after 15.3 Ma and the dramatic increase after 2.5 Ma, respectively.

  5. Regional Lithological Mapping Using ASTER-TIR Data: Case Study for the Tibetan Plateau and the Surrounding Area

    Directory of Open Access Journals (Sweden)

    Yoshiki Ninomiya

    2016-09-01

    Full Text Available The mineralogical indices the Quartz Index (QI, Carbonate Index (CI and Mafic Index (MI for ASTER multispectral thermal infrared (TIR data were applied to various geological materials for regional lithological mapping on the Tibetan Plateau. Many lithological and structural features are not currently well understood in the central Tibetan Plateau, including the distribution of mafic-ultramafic rocks related to the suture zones, the quartzose and carbonate sedimentary rocks accreted to the Eurasian continent, and sulfate layers related to the Tethys and neo-Tethys geological setting. These rock types can now be mapped with the interpretation of the processed ASTER TIR images described in this paper. A methodology is described for the processing of ASTER TIR data applied to a very wide region of the Tibetan Plateau. The geometrical and radiometric performance of the processed images is discussed, and the advantages of using ortho-rectified data are shown. The challenges of using ASTER data with a small footprint in addition to selecting an appropriate subset of scenes are also examined. ASTER scenes possess a narrow swath width when compared to LANDSAT data (60 km vs. 185 km, respectively. Furthermore, the ASTER data archive is vast, consisting of approximately three million images. These details can present an added level of complexity during an image processing workflow. Finally, geological interpretations made on the maps of the indices are compared with prior geological field studies. The results from the investigations suggest that the indices perform well in the classification of quartzose rocks based on the carbonate and mafic mineral content, in addition to the granitic rocks based on the feldspar content.

  6. [Effects of mulching and fertilization on winter wheat field soil moisture in dry highland region of Loess Plateau].

    Science.gov (United States)

    Wang, Xiao-Feng; Tian, Xiao-Hong; Chen, Zi-Hui; Chen, Hui-Lin; Wang, Zhao-Hui

    2009-05-01

    A field experiment was conducted in a winter wheat field in Weibei dry highland region of Loess Plateau to study the effects of different mulching and fertilization treatments on soil moisture regime. The treatments were 1) no fertilization, 2) conventional fertilization, 3) recommended fertilization, 4) recommended fertilization + manure, 5) recommended fertilization + plastic mulch on soil ridges, 6) recommended fertilization + plastic mulch on soil ridges and straw mulch in furrows, and 7) recommended fertilization + straw mulch on entire plot. Soil moisture content was determined regularly with a neutron probe. Among the treatments, recommended fertilization plus plastic mulch on soil ridges and straw mulch in furrows in dry season (spring) resulted in the greatest increase of soil water storage and maintained the storage to the critical stage crops needed, followed by recommended fertilization plus plastic mulch on soil ridges. These two treatments could store more precipitation in field, and would benefit the development of rainfed agriculture in dry highland region of Loess Plateau. As for recommended fertilization plus manure, it had the least increase of soil water storage, with a difference of 48.2 mm to the recommended fertilization plus plastic mulch on soil ridges and straw mulch in furrows in dry season.

  7. Multi‐scale topographic control of southwest vortex formation in Tibetan Plateau region in an idealized simulation

    National Research Council Canada - National Science Library

    Wang, Qi‐Wei; Tan, Zhe‐Min

    2014-01-01

    The southwest vortex (SWV) is a lee vortex occurring on the leeside of the Tibetan Plateau in southwestern China, which is strongly affected by the different scale topography of the Tibetan Plateau, Hengduan Cordillera, and Sichuan Basin...

  8. [Food habits and hunting patterns of Tibetan brown bear during warm seasons in Kekexili region on Qinghai-Tibetan Plateau].

    Science.gov (United States)

    Xu, Ai-Chun; Jiang, Zhi-Gang; Li, Chun-Wang; Cai, Ping

    2010-12-01

    Tibetan brown bear (Ursus arctos pruinosus) is an endemic subspecies of brown bear on the Qinghai-Tibetan plateau. We once reported a preliminary study on the summer food habit of Tibetan brown bear from July to August, 2005 in the Kekexili (Hoh Xil).. However, the hunting modes of the Tibetan brawn bear have not been reported. From July to August, 2009, we collected additional data on food habits and hunting patterns of Tibetan brown bear in the Kekexili region. We found Tibetan brown bears are more raptatorial than vegetarian, and their basal food was plateau pika (Ochotona curzoniae), relative frequency occurrence of pika in the fecal residual of brawn bear was 37.3%, dry weight of pika residuals was 44.7%, respectively, followed by wild yak (Bos grunniens) , 18.7% and 30.2%, and Tibetan antelope (Pantholops hodgsoni) 15.0% and 16.2%. Both prey actively mode and scavenge mode were used by Tibetan brown bears in Kekexili. Tibetan brawn bears actively dug and hunted for pika and scavenged bodies of wild yak, Tibetan antelope and Tibetan gazelle. We observed that Tibetan brawn bears spent about 10% of their time to dig and to hunt for pika but we had never seen Tibetan brawn bears actively hunted large mammals such as wild yak, Tibetan antelope and Tibetan gazelle. The total amount of Tibetan antelope, Tibetan gazelle and wild yak ingested by Tibetan brown bear through scavenge was about the same amount of Plateau pika and Himalayan marmot (Marmota himalayana) eaten by the bear.

  9. Nitrogen Eutrophication on the Colorado Plateau: Using Biological Indicators to Detect Nutrient Enrichment in the Grand Canyon Region

    Science.gov (United States)

    Kenkel, J. A.; Johnson, N.; Hultine, K. R.; Sesnie, S.; Sisk, T.

    2012-12-01

    Human activities have more than doubled the availability of biologically reactive forms of nitrogen (N) since the industrial and agricultural revolutions. Though N is an important plant nutrient, increased deposition initiates a cascade of deleterious effects including ecosystem acidification, biodiversity loss, and increased smog and haze. Atmospheric pollution continues to threaten the air quality of the 16 Class 1 Wilderness areas on the Colorado Plateau, including Grand Canyon National Park (GCNP). However, the ecological impacts of N deposition in these historically N-limited, nutrient sensitive arid regions, are little- known. Here, we report baseline atmospheric and terrestrial responses to anthropogenic N deposition derived from vehicular exhaust in GCNP and long-range deposition from a local coal-fired power plant, the Navajo Generating Station (NGS). We used passive air samplers, natural abundance δ15N stable isotope analysis, and nutrient analysis to observe N patterns in air, soils, and pinyon pine (Pinus edulis) foliage. In GCNP, samples were collected from ten sites over an eight-month period in areas of projected low to high vehicular N deposition (i.e. distance from primary roadways). On the Paria Plateau, northeast of GCNP and in close proximity to the NGS, samples were collected along a distance gradient from the NGS, across the Plateau. In both study areas, atmospheric deposition, as well as soil and pine- needle nutrient concentrations show significant negative relationships with increased distance from N-source (p<0.05). In heavily trafficked sites of GCNP, atmospheric nitrogen oxides (NOx) were 65% lower at 30m compared to the roadside. Likewise, on the Paria, NOx were 54% lower at 50km compared to 25km from NGS (p<0.01; R2 =0.87, for GCNP and the Paria, respectively). In GCNP, soil δ15N, and pinyon needle δ15N decrease significantly 30m from the roadside (18%, F= 4.07, p<0.05; 40%, F=4.34, p<0.05). On the Paria Plateau, soil δ15N, C

  10. Land-use types and soil chemical properties influence soil microbial communities in the semiarid Loess Plateau region in China.

    Science.gov (United States)

    Tian, Qin; Taniguchi, Takeshi; Shi, Wei-Yu; Li, Guoqing; Yamanaka, Norikazu; Du, Sheng

    2017-03-28

    Similar land-use types usually have similar soil properties, and, most likely, similar microbial communities. Here, we assessed whether land-use types or soil chemical properties are the primary drivers of soil microbial community composition, and how changes in one part of the ecosystem affect another. We applied Ion Torrent sequencing to the bacterial and fungal communities of five different land-use (vegetation) types in the Loess Plateau of China. We found that the overall trend of soil quality was natural forest > plantation > bare land. Dominant bacterial phyla consisted of Proteobacteria (42.35%), Actinobacteria (15.61%), Acidobacteria (13.32%), Bacteroidetes (8.43%), and Gemmatimonadetes (6.0%). The dominant fungi phyla were Ascomycota (40.39%), Basidiomycota (38.01%), and Zygomycota (16.86%). The results of Canonical Correspondence Analysis (CCA) and Redundancy Analysis (RDA) based on land-use types displayed groups according to the land-use types. Furthermore, the bacterial communities were mainly organized by soil organic carbon (SOC). The fungal communities were mainly related to available phosphorus (P). The results suggested that the changes of land use type generated changes in soil chemical properties, controlling the composition of microbial community in the semiarid Loess Plateau region. The microbial community could be an indicator for soil quality with respect to ecological restoration.

  11. Land-use types and soil chemical properties influence soil microbial communities in the semiarid Loess Plateau region in China

    Science.gov (United States)

    Tian, Qin; Taniguchi, Takeshi; Shi, Wei-Yu; Li, Guoqing; Yamanaka, Norikazu; Du, Sheng

    2017-01-01

    Similar land-use types usually have similar soil properties, and, most likely, similar microbial communities. Here, we assessed whether land-use types or soil chemical properties are the primary drivers of soil microbial community composition, and how changes in one part of the ecosystem affect another. We applied Ion Torrent sequencing to the bacterial and fungal communities of five different land-use (vegetation) types in the Loess Plateau of China. We found that the overall trend of soil quality was natural forest > plantation > bare land. Dominant bacterial phyla consisted of Proteobacteria (42.35%), Actinobacteria (15.61%), Acidobacteria (13.32%), Bacteroidetes (8.43%), and Gemmatimonadetes (6.0%). The dominant fungi phyla were Ascomycota (40.39%), Basidiomycota (38.01%), and Zygomycota (16.86%). The results of Canonical Correspondence Analysis (CCA) and Redundancy Analysis (RDA) based on land-use types displayed groups according to the land-use types. Furthermore, the bacterial communities were mainly organized by soil organic carbon (SOC). The fungal communities were mainly related to available phosphorus (P). The results suggested that the changes of land use type generated changes in soil chemical properties, controlling the composition of microbial community in the semiarid Loess Plateau region. The microbial community could be an indicator for soil quality with respect to ecological restoration. PMID:28349918

  12. Land-use types and soil chemical properties influence soil microbial communities in the semiarid Loess Plateau region in China

    Science.gov (United States)

    Tian, Qin; Taniguchi, Takeshi; Shi, Wei-Yu; Li, Guoqing; Yamanaka, Norikazu; Du, Sheng

    2017-03-01

    Similar land-use types usually have similar soil properties, and, most likely, similar microbial communities. Here, we assessed whether land-use types or soil chemical properties are the primary drivers of soil microbial community composition, and how changes in one part of the ecosystem affect another. We applied Ion Torrent sequencing to the bacterial and fungal communities of five different land-use (vegetation) types in the Loess Plateau of China. We found that the overall trend of soil quality was natural forest > plantation > bare land. Dominant bacterial phyla consisted of Proteobacteria (42.35%), Actinobacteria (15.61%), Acidobacteria (13.32%), Bacteroidetes (8.43%), and Gemmatimonadetes (6.0%). The dominant fungi phyla were Ascomycota (40.39%), Basidiomycota (38.01%), and Zygomycota (16.86%). The results of Canonical Correspondence Analysis (CCA) and Redundancy Analysis (RDA) based on land-use types displayed groups according to the land-use types. Furthermore, the bacterial communities were mainly organized by soil organic carbon (SOC). The fungal communities were mainly related to available phosphorus (P). The results suggested that the changes of land use type generated changes in soil chemical properties, controlling the composition of microbial community in the semiarid Loess Plateau region. The microbial community could be an indicator for soil quality with respect to ecological restoration.

  13. Trace elements and rare earth elements in wet deposition of Lijiang, Mt. Yulong region, southeastern edge of the Tibetan Plateau.

    Science.gov (United States)

    Guo, Junming; Kang, Shichang; Huang, Jie; Sillanpää, Mika; Niu, Hewen; Sun, Xuejun; He, Yuanqing; Wang, Shijing; Tripathee, Lekhendra

    2017-02-01

    In order to investigate the compositions and wet deposition fluxes of trace elements and rare earth elements (REEs) in the precipitation of the southeastern edge of the Tibetan Plateau, 38 precipitation samples were collected from March to August in 2012 in an urban site of Lijiang city in the Mt. Yulong region. The concentrations of most trace elements and REEs were higher during the non-monsoon season than during the monsoon season, indicating that the lower concentrations of trace elements and REEs observed during monsoon had been influenced by the dilution effect of increased precipitation. The concentrations of trace elements in the precipitation of Lijiang city were slightly higher than those observed in remote sites of the Tibetan Plateau but much lower than those observed in the metropolises of China, indicating that the atmospheric environment of Lijiang city was less influenced by anthropogenic emissions, and, as a consequence, the air quality was still relatively good. However, the results of enrichment factor and principal component analysis revealed that some anthropogenic activities (e.g., the increasing traffic emissions from the rapid development of tourism) were most likely important contributors to trace elements, while the regional/local crustal sources rather than anthropogenic activities were the predominant contributors to the REEs in the wet deposition of Lijiang city. Our study was relevant not only for assessing the current status of the atmospheric environment in the Mt. Yulong region, but also for specific management actions to be implemented for the control of atmospheric inputs and the health of the environment for the future. Copyright © 2016. Published by Elsevier B.V.

  14. Phylogeography and allopatric divergence of cypress species (Cupressus L. in the Qinghai-Tibetan Plateau and adjacent regions

    Directory of Open Access Journals (Sweden)

    Ciren Zhaxi

    2010-06-01

    Full Text Available Abstract Background Although allopatric speciation is viewed as the most common way in which species originate, allopatric divergence among a group of closely related species has rarely been examined at the population level through phylogeographic analysis. Here we report such a case study on eight putative cypress (Cupressus species, which each have a mainly allopatric distribution in the Qinghai-Tibetan Plateau (QTP and adjacent regions. The analysis involved sequencing three plastid DNA fragments (trnD-trnT, trnS-trnG and trnL-trnF in 371 individuals sampled from populations at 66 localities. Results Both phylogenetic and network analyses showed that most DNA haplotypes recovered or haplotype-clustered lineages resolved were largely species-specific. Across all species, significant phylogeographic structure (NST >GST, P C. duclouxiana and C. chengiana, which are distributed in the eastern QTP region, contained more haplotypes and higher diversity than five species with restricted distributions in the western highlands of the QTP. The remaining species, C. funebris, is widely cultivated and contained very little cpDNA diversity. Conclusions It is concluded that the formation of high mountain barriers separating deep valleys in the QTP and adjacent regions caused by various uplifts of the plateau since the early Miocene most likely promoted allopatric divergence in Cupressus by restricting gene flow and fixing local, species-specific haplotypes in geographically isolated populations. The low levels of intraspecific diversity present in most species might stem from population bottlenecks brought about by recurrent periods of unfavorable climate and more recently by the negative impacts of human activities on species' distributions. Our findings shed new light on the importance of geographical isolation caused by the uplift of the QTP on the development of high plant species diversity in the QTP biodiversity hotspot.

  15. Changing spring phenology dates in the Three-Rivers Headwater Region of the Tibetan Plateau during 1960-2013

    Science.gov (United States)

    Yu, Shuang; Xia, Jiangjiang; Yan, Zhongwei; Yang, Kun

    2018-01-01

    The variation of the vegetation growing season in the Three-Rivers Headwater Region of the Tibetan Plateau has recently become a controversial topic. One issue is that the estimated local trend in the start of the vegetation growing season (SOS) based on remote sensing data is easily affected by outliers because this data series is short. In this study, we determine that the spring minimum temperature is the most influential factor for SOS. The significant negative linear relationship between the two variables in the region is evaluated using Moderate Resolution Imaging Spectroradiometer-Normalized Difference Vegetation Index data for 2000-13. We then reconstruct the SOS time series based on the temperature data for 1960-2013. The regional mean SOS shows an advancing trend of 1.42 d (10 yr)-1 during 1960-2013, with the SOS occurring on the 160th and 151st days in 1960 and 2013, respectively. The advancing trend enhances to 6.04 d (10 yr)-1 during the past 14 years. The spatiotemporal variations of the reconstructed SOS data are similar to those deduced from remote sensing data during the past 14 years. The latter exhibit an even larger regional mean trend of SOS [7.98 d (10 yr-1)] during 2000-13. The Arctic Oscillation is found to have significantly influenced the changing SOS, especially for the eastern part of the region, during 2000-13.

  16. Analysing the environmental harms caused by coal mining and its protection measures in permafrost regions of Qinghai–Tibet Plateau

    Directory of Open Access Journals (Sweden)

    Wei Cao

    2017-09-01

    Full Text Available The coal mining has brought a series of ecological problems and environmental problems in permafrost regions. Taking Muli coal-mining area as an example, this article attempts to analyse the environmental harms caused by coal mining and its protection measures in permafrost regions of Qinghai–Tibet Plateau. This article analyses the influence of open mining on the surrounding permafrost around the open pit by using the numerical simulation. The results show that (1 based on the interrelation between coal mining and permafrost environment, these main environmental harm include the permafrost change and the natural environment change in cold regions; (2 once the surface temperature rises due to open mining, the permafrost will disappear with the increase of exploitation life. If considering the solar radiation, the climate conditions and the geological condition around the pit edge, the maximum thaw depth will be more than 2 m; (3 the protection measures are proposed to avoid the disadvantage impact on the permafrost environment caused by coal mining. It will provide a scientific basis for the resource development and environment protection in cold regions.

  17. Bias characteristics of temperature and relative humidity retrieved by microwave radiometer in Naqu region over the Tibetan Plateau

    Science.gov (United States)

    Zhuang, W.

    2016-12-01

    Radiosonde is the most basic method to measure the atmospheric temperature and humidity profiles with very coarse temporal resolution (2-4 times per day for conventional observation). But multiple simultaneous profiles of temperature, humidity, and so on can be obtained in 2-3 minutes temporal resolution with the microwave radiometer. In the third Tibetan Plateau experiment of Atmospheric Scientific organized by the Chinese Academy of Meteorological Sciences, synergic observations by ground-based multi-band radars and other detection equipments were used to study the microphysical processes of cloud and precipitation in Naqu area on the Tibetan Plateau. In this paper, profiles of temperature and relative humidity retrieved by microwave radiometer in different observation modes (zenith observation and off-zenith observation modes) are compared with collocated radiosondes during the summer period from 2014 to 2015 in Naqu region for different weather conditions defined by the data of millimeter wave cloud radar and raindrop spectrum. Three methods to compare the observation between microwave radiometer and radiosonde are temporal-spatial precision matching method, nearest temporal matching method and average profile method. The results show that: 1. Average profile method has the minimum difference between microwave radiometer retrievals and collocated sounding observation. 2. Profiles of temperature and relative humidity retrieved by microwave radiometer under zenith observation model and collocated sounding observation are more consistent under the condition of non-precipitation cloud than other weather conditions (clear sky and precipitation cloud). 3. Compared to zenith observation mode, the retrievals from the off-zenith observation mode of the microwave radiometer has a reasonable accuracy against the sounding observation. 4. In contract with cloudy sky, the retrievals by microwave radiometer and the sounding observation has the highest bias under the weather

  18. Subpixel Inundation Mapping Using Landsat-8 OLI and UAV Data for a Wetland Region on the Zoige Plateau, China

    Directory of Open Access Journals (Sweden)

    Haoming Xia

    2017-01-01

    Full Text Available Wetland inundation is crucial to the survival and prosperity of fauna and flora communities in wetland ecosystems. Even small changes in surface inundation may result in a substantial impact on the wetland ecosystem characteristics and function. This study presented a novel method for wetland inundation mapping at a subpixel scale in a typical wetland region on the Zoige Plateau, northeast Tibetan Plateau, China, by combining use of an unmanned aerial vehicle (UAV and Landsat-8 Operational Land Imager (OLI data. A reference subpixel inundation percentage (SIP map at a Landsat-8 OLI 30 m pixel scale was first generated using high resolution UAV data (0.16 m. The reference SIP map and Landsat-8 OLI imagery were then used to develop SIP estimation models using three different retrieval methods (Linear spectral unmixing (LSU, Artificial neural networks (ANN, and Regression tree (RT. Based on observations from 2014, the estimation results indicated that the estimation model developed with RT method could provide the best fitting results for the mapping wetland SIP (R2 = 0.933, RMSE = 8.73% compared to the other two methods. The proposed model with RT method was validated with observations from 2013, and the estimated SIP was highly correlated with the reference SIP, with an R2 of 0.986 and an RMSE of 9.84%. This study highlighted the value of high resolution UAV data and globally and freely available Landsat data in combination with the developed approach for monitoring finely gradual inundation change patterns in wetland ecosystems.

  19. Mapping seismic moment and b-value within the continental-collision orogenic-belt region of the Iranian Plateau

    Science.gov (United States)

    Mousavi, S. Mostafa

    2017-01-01

    In this paper, high-resolution map of the Gutenberg-Richter b-value and seismic moment-release are provided for the Iranian Plateau using the unified and homogeneous part of the seismicity record of the region (January 1995-July 2016). We use these parameters as stressmeters and qualitatively explore their correlations with the GPS velocity field, strain rate, faulting mechanism, attenuation, and structure of the region. Our goal is to reveal the correlations and anomalous patterns that can help to better understand the seismotectonics and the state of present-day crustal stress within the region. A negative correlation between b-value and seismic moment release as well as convergence rates is found. Correlation between geodetic measurements and seismic observations might indicate the existence of a strong mechanical coupling between the basement and the sediment cover across Zagros. High geodetic strain rates east of the Hormuz strait, southern central Alborz, and along the north Tabriz fault correspond to low b-value anomalies at these areas. A strong low b-value anomaly is observed at the major tectonic discontinuity between the Zagros continental collision and the oceanic Makran subduction.

  20. Crustal electric structure of Haiyuan arcuate tectonic region in the northeastern margin of Qinghai-Xizang Plateau, China

    Science.gov (United States)

    Zhan, Yan; Zhao, Guo-Ze; Wang, Ji-Jun; Tang, Ji; Chen, Xiao-Bin; Deng, Qian-Hui; Xuan, Fei; Zhao, Jun-Meng

    2005-07-01

    Through the analysis and 2-D inversion for the 5 profiles in Haiyuan arcuate tectonic region (105° 107°E, 36° 37.5°N) in the northeastern margin of Qinghai-Xizang Plateau, we have obtained the electric structure within a range of 160 km in width (east-west) and 60 km in depth in the studied area. The results show that the crustal electric structure can be divided into 6 sections, corresponding respectively to Xiji basin (I), Xihuashan-Nanhuashan uplift (II), Xingrenbu-Haiyuan basin (III), Zhongwei-Qingshuihe basin (IV), Zhongning-Hongsibu basin (V) and west-margin zone of Ordos (VI) from the southwest to the northeast. The crustal electric structure is characterized by a broom-shaped pattern, which scatters to the northwest and shrinks to the southeast. The structures in the top part of Haiyuan arcuate tectonic region are complete and large, however, they diminish from the arc top to the northwest and southeast ends. In the depth from 0 km to 10 km, the resistivity is high in the sections II and VI, but relatively low in the other four sections, showing a similar pattern of basin depression. The electrical basement in the section III is the deepest, displaying a “dustpan” shape that is deep in the southwest and shallow in the northeast. A series of discontinuous zones with high conductivity exist in the middle-lower crust in Haiyuan arcuate tectonic region, which is possibly related to the moderate and strong earthquakes in the region. The resistivity distribution in the focal area of the 1920 Haiyuan earthquake is significantly heterogeneous with an obviously high conductivity zone near the hypocenter regime.

  1. Regional effects of vegetation restoration on water yield across the Loess Plateau, China

    Science.gov (United States)

    X. M. Feng; G. Sun; B. J. Fu; C. H. Su; Y. Liu; H. Lamparski

    2012-01-01

    The general relationships between vegetation and water yield under different climatic regimes are well established at a small watershed scale in the past century. However, applications of these basic theories to evaluate the regional effects of land cover change on water resources remain challenging due to the complex interactions of vegetation and climatic variability...

  2. Neogene Fallout Tuffs from the Yellowstone Hotspot in the Columbia Plateau Region, Oregon, Washington and Idaho, USA

    Science.gov (United States)

    Nash, Barbara P.; Perkins, Michael E.

    2012-01-01

    Sedimentary sequences in the Columbia Plateau region of the Pacific Northwest ranging in age from 16–4 Ma contain fallout tuffs whose origins lie in volcanic centers of the Yellowstone hotspot in northwestern Nevada, eastern Oregon and the Snake River Plain in Idaho. Silicic volcanism began in the region contemporaneously with early eruptions of the Columbia River Basalt Group (CRBG), and the abundance of widespread fallout tuffs provides the opportunity to establish a tephrostratigrahic framework for the region. Sedimentary basins with volcaniclastic deposits also contain diverse assemblages of fauna and flora that were preserved during the Mid-Miocene Climatic Optimum, including Sucker Creek, Mascall, Latah, Virgin Valley and Trout Creek. Correlation of ashfall units establish that the lower Bully Creek Formation in eastern Oregon is contemporaneous with the Virgin Valley Formation, the Sucker Creek Formation, Oregon and Idaho, Trout Creek Formation, Oregon, and the Latah Formation in the Clearwater Embayment in Washington and Idaho. In addition, it can be established that the Trout Creek flora are younger than the Mascall and Latah flora. A tentative correlation of a fallout tuff from the Clarkia fossil beds, Idaho, with a pumice bed in the Bully Creek Formation places the remarkably well preserved Clarkia flora assemblage between the Mascall and Trout Creek flora. Large-volume supereruptions that originated between 11.8 and 10.1 Ma from the Bruneau-Jarbidge and Twin Falls volcanic centers of the Yellowstone hotspot in the central Snake River Plain deposited voluminous fallout tuffs in the Ellensberg Formation which forms sedimentary interbeds in the CRBG. These occurrences extend the known distribution of these fallout tuffs 500 km to the northwest of their source in the Snake River Plain. Heretofore, the distal products of these large eruptions had only been recognized to the east of their sources in the High Plains of Nebraska and Kansas. PMID:23071494

  3. Neogene fallout tuffs from the Yellowstone hotspot in the Columbia Plateau region, Oregon, Washington and Idaho, USA.

    Directory of Open Access Journals (Sweden)

    Barbara P Nash

    Full Text Available Sedimentary sequences in the Columbia Plateau region of the Pacific Northwest ranging in age from 16-4 Ma contain fallout tuffs whose origins lie in volcanic centers of the Yellowstone hotspot in northwestern Nevada, eastern Oregon and the Snake River Plain in Idaho. Silicic volcanism began in the region contemporaneously with early eruptions of the Columbia River Basalt Group (CRBG, and the abundance of widespread fallout tuffs provides the opportunity to establish a tephrostratigrahic framework for the region. Sedimentary basins with volcaniclastic deposits also contain diverse assemblages of fauna and flora that were preserved during the Mid-Miocene Climatic Optimum, including Sucker Creek, Mascall, Latah, Virgin Valley and Trout Creek. Correlation of ashfall units establish that the lower Bully Creek Formation in eastern Oregon is contemporaneous with the Virgin Valley Formation, the Sucker Creek Formation, Oregon and Idaho, Trout Creek Formation, Oregon, and the Latah Formation in the Clearwater Embayment in Washington and Idaho. In addition, it can be established that the Trout Creek flora are younger than the Mascall and Latah flora. A tentative correlation of a fallout tuff from the Clarkia fossil beds, Idaho, with a pumice bed in the Bully Creek Formation places the remarkably well preserved Clarkia flora assemblage between the Mascall and Trout Creek flora. Large-volume supereruptions that originated between 11.8 and 10.1 Ma from the Bruneau-Jarbidge and Twin Falls volcanic centers of the Yellowstone hotspot in the central Snake River Plain deposited voluminous fallout tuffs in the Ellensberg Formation which forms sedimentary interbeds in the CRBG. These occurrences extend the known distribution of these fallout tuffs 500 km to the northwest of their source in the Snake River Plain. Heretofore, the distal products of these large eruptions had only been recognized to the east of their sources in the High Plains of Nebraska and Kansas.

  4. Neogene fallout tuffs from the Yellowstone hotspot in the Columbia Plateau region, Oregon, Washington and Idaho, USA.

    Science.gov (United States)

    Nash, Barbara P; Perkins, Michael E

    2012-01-01

    Sedimentary sequences in the Columbia Plateau region of the Pacific Northwest ranging in age from 16-4 Ma contain fallout tuffs whose origins lie in volcanic centers of the Yellowstone hotspot in northwestern Nevada, eastern Oregon and the Snake River Plain in Idaho. Silicic volcanism began in the region contemporaneously with early eruptions of the Columbia River Basalt Group (CRBG), and the abundance of widespread fallout tuffs provides the opportunity to establish a tephrostratigrahic framework for the region. Sedimentary basins with volcaniclastic deposits also contain diverse assemblages of fauna and flora that were preserved during the Mid-Miocene Climatic Optimum, including Sucker Creek, Mascall, Latah, Virgin Valley and Trout Creek. Correlation of ashfall units establish that the lower Bully Creek Formation in eastern Oregon is contemporaneous with the Virgin Valley Formation, the Sucker Creek Formation, Oregon and Idaho, Trout Creek Formation, Oregon, and the Latah Formation in the Clearwater Embayment in Washington and Idaho. In addition, it can be established that the Trout Creek flora are younger than the Mascall and Latah flora. A tentative correlation of a fallout tuff from the Clarkia fossil beds, Idaho, with a pumice bed in the Bully Creek Formation places the remarkably well preserved Clarkia flora assemblage between the Mascall and Trout Creek flora. Large-volume supereruptions that originated between 11.8 and 10.1 Ma from the Bruneau-Jarbidge and Twin Falls volcanic centers of the Yellowstone hotspot in the central Snake River Plain deposited voluminous fallout tuffs in the Ellensberg Formation which forms sedimentary interbeds in the CRBG. These occurrences extend the known distribution of these fallout tuffs 500 km to the northwest of their source in the Snake River Plain. Heretofore, the distal products of these large eruptions had only been recognized to the east of their sources in the High Plains of Nebraska and Kansas.

  5. Tibial Plateau Fractures

    DEFF Research Database (Denmark)

    Elsøe, Rasmus

    This PhD thesis reported an incidence of tibial plateau fractures of 10.3/100,000/year in a complete Danish regional population. The results reported that patients treated for a lateral tibial plateau fracture with bone tamp reduction and percutaneous screw fixation achieved a satisfactory level...... with only the subgroup Sport significantly below the age matched reference population. The thesis reports a level of health related quality of life (Eq5d) and disability (KOOS) significantly below established reference populations for patients with bicondylar tibial plateau fracture treated with a ring...... fixator, both during treatment and at 19 months following injury. In general, the thesis demonstrates that the treatment of tibial plateau fractures are challenging and that some disabilities following these fractures must be expected. Moreover, the need for further research in the area, both with regard...

  6. Persistent organic pollutants in mountain air of the southeastern Tibetan Plateau: seasonal variations and implications for regional cycling.

    Science.gov (United States)

    Ren, Jiao; Wang, Xiaoping; Xue, Yonggang; Gong, Ping; Joswiak, Daniel R; Xu, Baiqing; Yao, Tandong

    2014-11-01

    In order to provide more conclusive evidence of monsoon-driven transport of persistent organic pollutants (POPs) to the Tibetan Plateau (TP) and assess the potential influence of forests on the fate of these pollutants, passive air samplers were consecutively deployed during 2008-2011 on Sygera Mountain (3800 m-4400 m). Higher DDTs levels were observed in the monsoon season (20.5-57.4 pg m(-3)) than the non-monsoon season (9.2-27.4 pg m(-3)), which confirmed that the Indian monsoon plays a key role in driving the atmospheric transport of DDTs to the TP. The similar DDT isomer ratios to the South Asia further suggested that Sygera Mountain is likely a receptor region of Indian subcontinent. By comparing the difference in concentrations between forest and clearing sites, it was found that the forest canopy can reduce airborne DDTs by a factor of 2, indicating strong absorption of DDTs by the Tibetan forest. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Creep characteristics and process analyses of a thaw slump in the permafrost region of the Qinghai-Tibet Plateau, China

    Science.gov (United States)

    Sun, Zhe; Wang, Yibo; Sun, Yan; Niu, Fujun; Li, Guoyu; Gao, Zeyong

    2017-09-01

    A thaw slump in the permafrost region of the Qinghai-Tibet Plateau was monitored to investigate typical characteristics of creep positions and processes in combination with soil property analyses. The results show that the thaw settlement exhibits a contraction effect in the horizontal direction because of uneven thaw settlement. Slope displacement of creep occurs only in the top 50 cm of the soil. The gravimetric water content, soil porosity, and soil temperature are higher near the thaw slump in thaw seasons compared with the undisturbed soil; however, the shear strength is lower. Melting ground ice releases thaw water that converges along the slope and forms an overland flow at the front part of the gentle slope area and a ponding depression at the slope bottom. The analyses of slope stability using the infinite slope model shows that the headwall of the slope is inevitably unstable and slides under saturated conditions, whereas the gentle slope area and slope bottom with slight creep displacement are relatively stable. The small retrogressive thaw slump is in an early development stage. With increasing degree of thaw settlement and rate of erosion, the headwall will become steeper and a thermokarst lake will form at the slope bottom.

  8. [Vegetation above-ground biomass and its affecting factors in water/wind erosion crisscross region on Loess Plateau].

    Science.gov (United States)

    Wang, Jian-guo; Fan, Jun; Wang, Quan-jiu; Wang, Li

    2011-03-01

    Field investigations were conducted in Liudaogou small watershed in late September 2009 to study the differences of vegetation above-ground biomass, soil moisture content, and soil nutrient contents under different land use patterns, aimed to approach the vegetation above-ground biomass level and related affecting factors in typical small watershed in water/wind erosion crisscross region on Loess Plateau. The above-ground dry biomass of the main vegetations in Liudaogou was 177-2207 g x m(-2), and that in corn field, millet field, abandoned farmland, artificial grassland, natural grassland, and shrub land was 2097-2207, 518-775, 248-578, 280-545, 177-396, and 372-680 g x m(-2), respectively. The mean soil moisture content in 0-100 layer was the highest (14.2%) in farmlands and the lowest (10.9%) in shrub land. The coefficient of variation of soil moisture content was the greatest (26. 7% ) in abandoned farmland, indicating the strong spatial heterogeneity of soil moisture in this kind of farmland. The mean soil water storage was in the order of farmland > artificial grassland > natural grassland > shrub land. Soil dry layer was observed in alfalfa and caragana lands. There was a significant positive correlation (r = 0.639, P nutrient contents, but had no significant correlations with elevation, slope gradient, slope aspect, and soil bulk density.

  9. Mapping Plant Functional Types over Broad Mountainous Regions: A Hierarchical Soft Time-Space Classification Applied to the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Danlu Cai

    2014-04-01

    Full Text Available Research on global climate change requires plant functional type (PFT products. Although several PFT mapping procedures for remote sensing imagery are being used, none of them appears to be specifically designed to map and evaluate PFTs over broad mountainous areas which are highly relevant regions to identify and analyze the response of natural ecosystems. We present a methodology for generating soft classifications of PFTs from remotely sensed time series that are based on a hierarchical strategy by integrating time varying integrated NDVI and phenological information with topography: (i Temporal variability: a Fourier transform of a vegetation index (MODIS NDVI, 2006 to 2010. (ii Spatial partitioning: a primary image segmentation based on a small number of thresholds applied to the Fourier amplitude. (iii Classification by a supervised soft classification step is based on a normalized distance metric constructed from a subset of Fourier coefficients and complimentary altitude data from a digital elevation model. Applicability and effectiveness is tested for the eastern Tibetan Plateau. A classification nomenclature is determined from temporally stable pixels in the MCD12Q1 time series. Overall accuracy statistics of the resulting classification reveal a gain of about 7% from 64.4% compared to 57.7% by the MODIS PFT products.

  10. Sedimentary and crustal thicknesses and Poisson's ratios for the NE Tibetan Plateau and its adjacent regions based on dense seismic arrays

    Science.gov (United States)

    Wang, Weilai; Wu, Jianping; Fang, Lihua; Lai, Guijuan; Cai, Yan

    2017-03-01

    The sedimentary and crustal thicknesses and Poisson's ratios of the NE Tibetan Plateau and its adjacent regions are estimated by the h- κ stacking and CCP image of receiver functions from the data of 1,317 stations. The horizontal resolution of the obtained results is as high as 0.5° × 0.5°, which can be used for further high resolution model construction in the region. The crustal thicknesses from Airy's equilibrium are smaller than our results in the Sichuan Basin, Qilian tectonic belt, northern Alxa block and Qaidam Basin, which is consistent with the high densities in the mantle lithosphere and may indicate that the high-density lithosphere drags crust down overall. High Poisson's ratios and low velocity zones are found in the mid- and lower crust beneath eastern Qilian tectonic belt and the boundary areas of the Ordos block, indicating that partial melting may exist in these regions. Low Poisson's ratios and low-velocity anomalies are observed in the crust in the NE Tibetan Plateau, implying that the mafic lower crust is thinning or missing and that the mid- and lower crust does not exhibit melting or partial melting in the NE Tibetan Plateau, and weak flow layers are not likely to exist in this region.

  11. Atmospheric processes of organic pollutants over a remote lake on the central Tibetan Plateau: implications for regional cycling

    Science.gov (United States)

    Ren, Jiao; Wang, Xiaoping; Wang, Chuanfei; Gong, Ping; Yao, Tandong

    2017-01-01

    Atmospheric processes (air-surface exchange, and atmospheric deposition and degradation) are crucial for understanding the global cycling and fate of organic pollutants (OPs). However, such assessments over the Tibetan Plateau (TP) remain uncertain. More than 50 % of Chinese lakes are located on the TP, which exerts a remarkable influence on the regional water, energy, and chemical cycling. In this study, air and water samples were simultaneously collected in Nam Co, a large lake on the TP, to test whether the lake is a secondary source or sink of OPs. Lower concentrations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were observed in the atmosphere and lake water of Nam Co, while the levels of polycyclic aromatic hydrocarbons (PAHs) were relatively higher. Results of fugacity ratios and chiral signatures both suggest that the lake acted as the net sink of atmospheric hexachlorocyclohexanes (HCHs), following their long-range transport driven by the Indian monsoon. Different behaviours were observed in the PAHs, which primarily originated from local biomass burning. Acenaphthylene, acenaphthene, and fluorene showed volatilization from the lake to the atmosphere, while other PAHs were deposited into the lake due to the integrated deposition process (wet/dry and air-water gas deposition) and limited atmospheric degradation. As the dominant PAH compound, phenanthrene exhibited a seasonal reversal of air-water gas exchange, which was likely related to the melting of the lake ice in May. The annual input of HCHs from the air to the entire lake area (2015 km2) was estimated as 1.9 kg yr-1, while input estimated for ∑ 15PAHs can potentially reach up to 550 kg yr-1. This study highlights the significance of PAH deposition on the regional carbon cycling in the oligotrophic lakes of the TP.

  12. Quantifying the Effects of Conservation Practices on Soil, Water, and Nutrients in the Loess Mesa Ravine Region of the Loess Plateau, China

    Science.gov (United States)

    Xu, Xiang-Zhou; Li, Mei-Juan; Liu, Bin; Kuang, Shang-Fu; Xu, Shi-Guo

    2012-05-01

    A large number of soil and water conservation programs have been implemented on the Loess Plateau of China since the 1950s. To comprehensively assess the merits and demerits of the conservation practices is of great importance in further supervising the conservation strategy for the Loess Plateau. This study calculates the impact factors of conservation practices on soil, water, and nutrients during the period 1954-2004 in the Nanxiaohegou Catchment, a representative catchment in the Loess Mesa Ravine Region of the Loess Plateau, China. Brief conclusions could be drawn as follows: (1) Soil erosion and nutrient loss had been greatly mitigated through various conservation practices. About half of the total transported water and 94.8 % of the total transported soil and nutrients, had been locally retained in the selected catchment. The soil retained from small watersheds do not only form large-scale fertile farmland but also safeguard the Yellow River against overflow. (2) Check dam was the most appropriate conservation practice on the Loess Plateau. In the selected catchment, more than 90 % of the retained soil and water were accomplished by the dam farmland, although the dam farmland occupied only 2.3 % of the total area of all conservation measures. Retention abilities of the characteristic conservation practices were in the following order: dam farmland > terrace farmland > forest land and grassland. (3) The conservation practices were more powerful in retaining sediment than in reducing runoff from the Loess Plateau, and the negative effects of the conservation practices on reducing water to the Yellow River were relatively slight.

  13. Impact of climate variability and anthropogenic activity on streamflow in the Three Rivers Headwater Region, Tibetan Plateau, China

    Science.gov (United States)

    Jiang, Chong; Li, Daiqing; Gao, Yanni; Liu, Wenfeng; Zhang, Linbo

    2017-07-01

    Under the impacts of climate variability and human activities, there is violent fluctuation for streamflow in the large basins in China. Therefore, it is crucial to separate the impacts of climate variability and human activities on streamflow fluctuation for better water resources planning and management. In this study, the Three Rivers Headwater Region (TRHR) was chosen as the study area. Long-term hydrological data for the TRHR were collected in order to investigate the changes in annual runoff during the period of 1956-2012. The nonparametric Mann-Kendall test, moving t test, Pettitt test, Mann-Kendall-Sneyers test, and the cumulative anomaly curve were used to identify trends and change points in the hydro-meteorological variables. Change point in runoff was identified in the three basins, which respectively occurred around the years 1989 and 1993, dividing the long-term runoff series into a natural period and a human-induced period. Then, the hydrologic sensitivity analysis method was employed to evaluate the effects of climate variability and human activities on mean annual runoff for the human-induced period based on precipitation and potential evapotranspiration. In the human-induced period, climate variability was the main factor that increased (reduced) runoff in LRB and YARB (YRB) with contribution of more than 90 %, while the increasing (decreasing) percentage due to human activities only accounted for less than 10 %, showing that runoff in the TRHR is more sensitive to climate variability than human activities. The intra-annual distribution of runoff shifted gradually from a double peak pattern to a single peak pattern, which was mainly influenced by atmospheric circulation in the summer and autumn. The inter-annual variation in runoff was jointly controlled by the East Asian monsoon, the westerly, and Tibetan Plateau monsoons.

  14. Landcover Change, Land Surface Temperature, Surface Albedo and Topography in the Plateau Region of North-Central Nigeria

    Directory of Open Access Journals (Sweden)

    Shakirudeen Odunuga

    2015-04-01

    Full Text Available This study assessed the change in some environmental parameters in the Plateau region of North-Central Nigeria (Barakinladi, Jos, and Kafachan environs using the nexus of landcover change, land surface temperature, surface albedo, and topography. The study employed both remote sensing and statistical techniques for the period between 1986 and 2014 to analyze the dynamics between and within these environmental variables. In Barakinladi, the built up landcover change is highest (increasing from 39.53% to 47.59% between 1986 and 2014; LST ranges from 19.09 °C to 38.59 °C in 1986 and from 22.68 °C and 41.68 °C in 2014; and the albedo ranges between 0.014 and 0.154 in 1986 and 0.017 and 0.248 in 2014. In Jos, the built-up landcover occupied 34.26% in 1986 and 36.67% in 2014; LST values range between 20.83 °C and 41.33 °C in 1986 and between 21.61 °C and 42.64 °C in 2014; and the albedo ranges between 0.003 and 0.211 in 1986 and 0.15 and 0.237 in 2014. In Kafachan area, the built up landcover occupied 32.95% in 1986 and 39.01% in 2014. Urbanization and agricultural activities, including animal grazing, were responsible for the gradual loss in vegetation and increasing average LST and albedo. The results also revealed that changing landcover and topography have a relationship with surface albedo and land surface temperature, thereby impacting significantly on ecosystem services delivered by the natural system.

  15. Evaluation of Five Grid Datasets against Radiosonde Data over the Eastern and Downstream Regions of the Tibetan Plateau in Summer

    Directory of Open Access Journals (Sweden)

    Yuanchang Dong

    2017-03-01

    Full Text Available In this study, horizontal wind (U and V, air temperature (T, and relative humidity (RH modelled by the European Centre for Medium-Range Weather Forecasts Reanalysis Interim (ERA-Interim, the National Aeronautics and Space Administration (NASA Modern Era Retrospective Analysis for Research and Applications (MERRA, the Japanese 55-year Reanalysis (JRA-55, the National Centers for Environmental Prediction (NCEP Climate Forecast System Version 2 (CFSv2, and the NCEP Final Operational Global Analysis data and the NCEP Final Operational Global Analysis data (NCEP-FNL products have been compared with observations at 11 radiosonde stations over the eastern and downstream regions of the Tibetan Plateau (TP from late June until the end of July during 2011 to 2015. The mean bias of all variables for the five gridded datasets (GDs in the Sichuan Basin (SCB is larger than that for the TP. The mean values of U, V, and T from each grid dataset are generally consistent with the radiosonde values, whereas considerable bias in the mean RH exists at upper levels. The diurnal variation of the mean bias and root-mean-square (RMS error in the basin are stronger than those in the TP and the negative/positive peak usually occurs at 06:00 UTC and 18:00 UTC in the basin or at 12:00 UTC in the TP. The inter-annual variations in the basin are significantly stronger, and the maximum values of the variations usually occur at upper levels or near the surface, except for V. The weather conditions have a crucial influence on the performance of the gridded datasets. The mean bias and RMS error of T in the TP on cloudy days are obviously larger than those during sunny conditions. Considerable but unsteady differences occur in the mean bias and RMS error of U and V in different weather conditions. On average, the four variables in the TP are more sensible to the weather conditions.

  16. [Responses of plant functional traits to micro-topographical changes in hilly and gully region of the Loess Plateau, China].

    Science.gov (United States)

    Yang, Shi-suo; Wen, Zhong-ming; Miao, Lian-peng; Qi, De-hui; Hua, Dong-wen

    2014-12-01

    Plant functional traits are closely tied to the performance of plants in specific microenvironments, and reflect their ability to adapt to those microenvironments. In areas with complex topography, analyzing the responses of plant functional traits to microtopographical changes is crucial to understanding the adaptive strategies of plants in diverse environments. This paper analyzed fluctuations in soil nutrients as well as correlations between plant functional traits and changes in topography at the family and community levels in selected natural vegetation communities in the foreststeppe zone of the loess hilly and gully region in Loess Plateau of China. Significant differences in plant functional traits were primarily driven by the phylogenetic background or species composition of the community. Slope aspect exerted less impact while slope positions had no significant effect on plant traits at the community level. No significant changes in plant functional traits were observed with changes in topography at the community level. However, leaf nitrogen and root nitrogen contents of Leguminous and Compositae species differed significantly With slope positions. The root tissue density of Graminaceous species differed significantly with slope positions. Root density exhibited significant positive correlations with soil nutrient and carbon contents at the community level. Both leaf nitrogen and root nitrogen contents of Leguminous species were positively correlated with soil phosphorus content, while leaf nitrogen and root nitrogen contents of both Graminaceous and Compositae species were significantly positively related to soil nitrogen content. The results demonstrate the different responses of species of different families to changes in micro-topography and their distinctive adaptive strategies to the environment.

  17. Hydrogeologic framework and hydrologic budget components of the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho

    Science.gov (United States)

    Kahle, S.C.; Morgan, D.S.; Welch, W.B.; Ely, D.M.; Hinkle, S.R.; Vaccaro, J.J.; Orzol, L.L.

    2011-01-01

    The Columbia Plateau Regional Aquifer System (CPRAS) covers an area of about 44,000 square miles in a structural and topographic basin within the drainage of the Columbia River in Washington, Oregon, and Idaho. The primary aquifers are basalts of the Columbia River Basalt Group (CRBG) and overlying sediment. Eighty percent of the groundwater use in the study area is for irrigation, in support of a $6 billion per year agricultural economy. Water-resources issues in the Columbia Plateau include competing agricultural, domestic, and environmental demands. Groundwater levels were measured in 470 wells in 1984 and 2009; water levels declined in 83 percent of the wells, and declines greater than 25 feet were measured in 29 percent of the wells. Conceptually, the system is a series of productive basalt aquifers consisting of permeable interflow zones separated by less permeable flow interiors; in places, sedimentary aquifers overly the basalts. The aquifer system of the CPRAS includes seven hydrogeologic units-the overburden aquifer, three aquifer units in the permeable basalt rock, two confining units, and a basement confining unit. The overburden aquifer includes alluvial and colluvial valley-fill deposits; the three basalt units are the Saddle Mountains, Wanapum, and Grande Ronde Basalts and their intercalated sediments. The confining units are equivalent to the Saddle Mountains-Wanapum and Wanapum-Grande Ronde interbeds, referred to in this study as the Mabton and Vantage Interbeds, respectively. The basement confining unit, referred to as Older Bedrock, consists of pre-CRBG rocks that generally have much lower permeabilities than the basalts and are considered the base of the regional flow system. Based on specific-capacity data, median horizontal hydraulic conductivity (Kh) values for the overburden, basalt units, and bedrock are 161, 70, and 6 feet per day, respectively. Analysis of oxygen isotopes in water and carbon isotopes in dissolved inorganic carbon from

  18. [Effects of land use and environmental factors on the variability of soil quality indicators in hilly Loess Plateau region of China].

    Science.gov (United States)

    Xu, Ming-Xiang; Liu, Guo-Bin; Zhao, Yun-Ge

    2011-02-01

    Classical statistics methods were adopted to analyze the soil quality variability, its affecting factors, and affecting degree at a regional scale (700 km2) in the central part of hilly Loess Plateau region of China. There existed great differences in the variability of test soil quality indicators. Soil pH, structural coefficient, silt content, specific gravity, bulk density, total porosity, capillary porosity, and catalase activity were the indicators with weak variability; soil nutrients (N, P, and K) contents, CaCO3 content, cation exchange capacity (CEC), clay content, micro-aggregate mean mass diameter, aggregate mean mass diameter, water-stable aggregates, respiration rate, microbial quotient, invertase and phosphatase activities, respiratory quotient, and microbial carbon and nitrogen showed medium variation; while soil labile organic carbon and phosphorus contents, erosion-resistance, permeability coefficient, and urease activity were the indicators with strong variability. The variability of soil CaCO3, total P and K, CEC, texture, and specific gravity, etc. was correlated with topography and other environmental factors, while the variability of dynamic soil quality indicators, including soil organic matter content, nitrogen content, water-stable aggregates, permeability, microbial biomass carbon and nitrogen, enzyme activities, and respiration rate, was mainly correlated with land use type. Overall, land use pattern explained 97% of the variability of soil quality indicators in the region. It was suggested that in the evaluation of soil quality in hilly Loess Plateau region, land use type and environmental factors should be fully considered.

  19. Diurnal and Seasonal Variations in the Net Ecosystem CO2 Exchange of a Pasture in the Three-River Source Region of the Qinghai?Tibetan Plateau

    OpenAIRE

    Wang, Bin; Jin, Haiyan; Li, Qi; Chen, Dongdong; Zhao,Liang; Tang, Yanhong; Kato, Tomomichi; Gu, Song

    2017-01-01

    Carbon dioxide (CO2) exchange between the atmosphere and grassland ecosystems is very important for the global carbon balance. To assess the CO2 flux and its relationship to environmental factors, the eddy covariance method was used to evaluate the diurnal cycle and seasonal pattern of the net ecosystem CO2 exchange (NEE) of a cultivated pasture in the Three-River Source Region (TRSR) on the Qinghai?Tibetan Plateau from January 1 to December 31, 2008. The diurnal variations in the NEE and eco...

  20. [Biological soil crust nitrogenase activity and its responses to hydro-thermic factors in different erosion regions on the Loess Plateau, China].

    Science.gov (United States)

    Ming, Jiao; Zhao, Yun-Ge; Xu, Ming-Xiang; Yang, Li-Na; Wang, Ai-Guo

    2013-07-01

    Based on field survey, the biological soil crusts at their stable development stage were collected from the water erosion region, water-wind erosion region, and wind erosion region on the Loess Plateau, aimed to study the effects of the variations of moisture and temperature on the crusts nitrogenase activity (NA). The NA of the crusts in the erosion regions decreased in the order of water erosion region (127.7 micromol x m(-2) x h(-1)) > water-wind erosion region (34.6 micromol x m(-2) x h(-1)) > wind erosion region (6.0 micromol x m(-2) x h(-1)), and the optimal temperature for the crust nitrogen fixation was 35 degrees C, 25 degrees C, and 15 degrees C, respectively. At the optimal temperature and 100% -40% field water-holding capacity, the NA of the crusts from the water erosion and water-wind erosion regions had no significant difference. The NA of the crusts from the wind erosion region was more sensitive to the variation of moisture, showing a dramatic decline when the moisture decreased to 80% field water-holding capacity, and totally lost when the moisture decreased to 20% field water-holding capacity. The differences in the NA of the crusts from the three erosion regions and the responses of the NA to the variations of moisture and temperature were likely associated with the climate, environment, and the crust species composition.

  1. Dynamic analysis of eco-environmental changes based on remote sensing and geographic information system: an example in Longdong region of the Chinese Loess Plateau

    Science.gov (United States)

    Liu, L. C.; Dong, X. F.; Wang, J. H.

    2007-11-01

    The Chinese Loess Plateau is suffering from severe soil erosion. The eco-environmental changes of the plateau are believed to have an important influence on global eco-environmental sustainability; hence, this problem has attracted considerable attention from scientists around the world. This study has two purposes; application of remote sensing (RS) and geographic information system (GIS) techniques in the dynamic analysis of eco-environmental changes in the semiarid zone; and using the Longdong region of the Chinese Loess Plateau as an example, to make dynamic analysis of the eco-environmental changes of the region during the 1986 2004 period and identify controlling factors. Landsat Thematic Mapper (TM) data at a spatial resolution of 30 m were used for analysis. Two training areas were selected in Jingning and Qingcheng counties for analysis using 10-m resolution SPOT and Landsat TM data. The satellite RS images were obtained from the Institute of Remote Sensing Application (IRSA), Chinese Academy of Sciences (CAS). Each images was rectified by Albers Equal Area Conic projection based on 1:50,000 scale topographic maps after spectrum preparation of the images. To make the precision within 1 or 2 pixels, the accurate coordinative control points of the two systems were identified. Then the interpretation key was established based on the land use/cover survey in the study area. The images were classified into six primary environmental types (farmland, forest, grassland, water, construction area, and desert) and 25 sub-types using a visual image interactive interpretation method to obtain vector and attribute data. The resultant accuracy of the land use/cover classification reached 95%. Finally, the transformation areas and ratios of various eco-environmental types in the region were calculated to obtain the transition matrixes of eco-environmental types in the two training areas, Jingning and Qingcheng. This study demonstrates that satellite RS and GIS techniques

  2. Analysis of Basin-Range Coupling Mechanisms during Epeirogenetic Uplift - A Case Study of Tectonic Coupling in the Songpan-Ganzi Plateau-Longmen Mountain-Sichuan Basin Region

    Science.gov (United States)

    Ying, Danlin; Li, Ying

    2017-04-01

    The tectonodynamic evolution of the Songpan-Ganzi Plateau-Longmen Mountain-Sichuan basin region has been analyzed in this paper. The result suggested that the region had experienced principal four stages of evolution. The evolution was beginning with crystalline basement and folded basement formation in the pre-Sinian, then the cartonmarine sedimentary basin from the Sinian to the Middle Triassic was followed by uplift and stretching of the land from the Late Triassic to the Middle Jurassic, and finally compressive orogenesis since the Late Jurassic was happened. To understand the uplift and stretching of the land from the Late Triassic to the Middle Jurassic, a physical modeling experiment was conducted. It was confirmed that a tectonic plateau-ramp-basin geomorphology pattern developed during this period, caused by the wide difference in uplift between the Songpan-Ganzi Plateau and the Sichuan Basin. In the plateau region, the tectonic dynamic environment of uplift and stretching of the land (trailing edge extension) had appeared, which was accompany with the extensional structure styles such as normal faults and graben-horst structures. On the slope between the plateau and the basin, a bedding shear geodynamic environment was formed, and compressive slumped overthrust structure was found for the sliddown of decollement layers under the force of gravity. In the basin, compressive tectonic dynamic environment had emerged, which leaded to a compressive structure, such as thrust faults, overturned folds, and fault-related folds.

  3. Multicriteria decision analysis for monitoring ecosystem service function of the Three-River Headwaters region of the Qinghai-Tibet Plateau, China.

    Science.gov (United States)

    Zhu, Jinfeng; Zhou, Yi; Wang, Shixin; Wang, Litao; Wang, Futao; Liu, Wenliang; Guo, Bing

    2015-06-01

    The Three-River Headwaters (TRH) region in the Qinghai-Tibet Plateau, China, is of key importance to the ecological security of China and Southeast Asia and contains some of the most sensitive and fragile ecosystems. Monitoring and evaluating the ecosystem service function and its changes in the TRH region could support decision-making for regional ecological protection and restoration programs. Referencing the concept of ecosystem service and the Millennium Ecosystem Assessment (MA) framework, this study built a system of indicators for monitoring and evaluating the ecosystem service function. Thus, combining a multicriteria decision analysis (MCDA) and weighted linear combination (WLC) with analytic hierarchy process (AHP), we applied the ecosystem service function index (ESFI) based on remote sensing data at 1-km spatial resolution to spatiotemporally monitor the changes during the period 2005-2010. The study results indicated that ESFI had a good performance for monitoring the ecosystem service function and showed an improving trend in the TRH region over the past 5 years. Ecosystem environment recovery not only reflected the changing trend of warm and wet climate but was also a response of the ecological protection project of the Key Ecological Function Zone in the TRH region.

  4. Application of a modified distributed-dynamic erosion and sediment yield model in a typical watershed of a hilly and gully region, Chinese Loess Plateau

    Science.gov (United States)

    Wu, Lei; Liu, Xia; Ma, Xiaoyi

    2016-11-01

    Soil erosion not only results in the destruction of land resources and the decline of soil fertility, but also contributes to river channel sedimentation. In order to explore the spatiotemporal evolution of erosion and sediment yield before and after returning farmland in a typical watershed of the hilly and gully region (Chinese Loess Plateau), a distributed-dynamic model of sediment yield based on the Chinese Soil Loss Equation (CSLE) was established and modified to assess the effects of hydrological factors and human activities on erosion and sediment yield between 1995 and 2013. Results indicate that (1) the modified model has the characteristics of a simple algorithm, high accuracy, wide practicability and easy expansion, and can be applied to predict erosion and sediment yield in the study area, (2) soil erosion gradations are closely related to the spatial distribution of rainfall erosivity and land use patterns, and the current soil and water conservation measures are not efficient for high rainfall intensities, and (3) the average sediment yield rate before and after model modification in the most recent 5 years (in addition to 2013) is 4574.62 and 1696.1 Mg km-2, respectively, decreasing by about 35.4 and 78.2 % when compared to the early governance (1995-1998). However, in July 2013 the once-in-a-century storm is the most important reason for maximum sediment yield. Results may provide an effective and scientific basis for soil and water conservation planning and ecological construction of the hilly and gully region, Chinese Loess Plateau.

  5. Beryllium-7 measurements of wind erosion on sloping fields in the wind-water erosion crisscross region on the Chinese Loess Plateau.

    Science.gov (United States)

    Zhang, Jiaqiong; Yang, Mingyi; Deng, Xinxin; Liu, Zhang; Zhang, Fengbao; Zhou, Weiying

    2018-02-15

    Soil erosion is complex in the wind-water erosion crisscross region of the Chinese Loess Plateau, as interleaving of wind and water erosion occurs on both temporal and spatial scales. It is difficult to distinguish wind erosion from the total erosion in previous studies due to the untraceable of aeolian particles and the limitation of feasible methods and techniques. This study used beryllium-7 measurements to study wind erosion in the wind-water erosion crisscross region on the Chinese Loess Plateau arms to delineate wind erosion distribution, to analyze its implication to erosive winds and surface microrelief, and to determine correlations between erosion rates and slope gradients. Results obtained using beryllium-7 measurements based on observation plots were verified with saltating particle collection method, and were also verified on a field scale. Results indicated that the effective resultant erosion wind was from northward, which was proved by the eight-directional distributed saltating particles. The microrelief of the ground surface contributed to the formation of high or low erosion centers. Wind erosion rates increased with a linear (R 2 ≥0.95) or exponential (R 2 ≥0.83) fitting increase in the slope gradients as reported in previous studies. Compared to wind erosion on field scale, both the plots and fields exhibited similar distribution patterns in wind erosion isolines. We also determined that the wind erosion rate for two fields estimated, based on equations developed from plot scale was acceptable. This study validates the feasibility of beryllium-7 measurements for soil-wind erosion field experiments and the potential to expand this approach to real field conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. On the formation and evolution of sinuous rilles: Morphologic and morphometric insights from the Marius Hills and Aristarchus Plateau regions

    Science.gov (United States)

    Roberts, Carolyn Eve

    Lunar sinuous rilles are characteristically long (100-350 km), narrow (formed within expansive sheet flows as preferred pathways along the pre-eruptive surface that developed into lava tubes as the eruption continued. Geologic sketch maps reveal outcrop layering, exposed in rille walls, that is consistent with sheet flow emplacement and small, anastomosing "rillettes" around Rima Marius, suggesting that initial tubes intermingled and coalesced to form larger tubes. From terrestrial basalt flow emplacement observations, I infer that as the outer boundaries of the Rima Marius-forming sheet flow cooled, the remaining lava was forced toward the main tube and downcutting transpired at the flow base. Once the eruption concluded, lava drained out of the main tube; the dimensions of the hollow tube lead to roof collapse, resulting in the general rille structure observed today. Results from the morphometric analysis indicate that sinuous rille characteristics (length, width, sinuosity, radius of curvature, number of curves, and fractal dimension) are similar between the two highest lunar sinuous rille populations at Marius Hills and Aristarchus Plateau. Moreover, the number of curves increases linearly with rille length and a weak correlation exists between sinuosity and fractal dimension. Compared to terrestrial rivers, sinuous rilles have lower amplitudes, smaller sinuosity values and fractal dimension values. The preponderance of evidence indicates sinuous rilles formed through a combination of both constructional and erosional processes.

  7. Impact of the model resolution on the simulation of elevation-dependent warming in the Tibetan Plateau-Himalayas, Greater Alpine Region, and Rocky mountains

    Science.gov (United States)

    Palazzi, Elisa; Mortarini, Luca; Terzago, Silvia; von Hardenberg, Jost

    2017-04-01

    The enhancement of warming rates with elevation, the so-called elevation-dependent warming (EDW), is one of the clearest regional expressions of global warming. Real sentinels of climate and environmental changes, mountains have experienced more rapid and intense warming rates in the recent decades, leading to serious impacts on mountain ecosystems and downstream societies, some of which are already occurring. In this study we use the historical and scenario simulations of one state-of-the-art global climate model, the EC-Earth GCM, run at five different spatial resolutions, from ˜125 km to ˜16 km, to explore the existence, characteristics and driving mechanisms of EDW in three different mountain regions of the world - the Colorado Rocky Mountains, the Greater Alpine Region and the Tibetan Plateau-Himalayas. The aim of this study is twofold: to investigate the impact (if any) of increasing model resolution on the representation of EDW and to highlight possible differences in this phenomenon and its driving mechanisms in different mountain regions of the northern hemisphere. Preliminary results indicate that autumn (September to November) is the only season in which EDW is simulated by the model in both the maximum and the minimum temperature, in all three regions and across all model resolutions. Regional differences emerge in the other seasons: for example, the Tibetan Plateau-Himalayas is the only area in which EDW is detected in winter. As for the analysis of EDW drivers, we identify albedo and downward longwave radiation as being the most important variables for EDW, in all three areas considered and in all seasons. Further these results are robust to changes in model resolution, even though a clearer signal is associated with finer resolutions. We finally use the highest resolution EC-Earth simulations available (˜16 km) to identify what areas, within the three considered mountain ranges, are expected to undergo a significant reduction of snow or ice cover

  8. Holocene lake stages and thermokarst dynamics in a discontinuous permafrost affected region, north-eastern Tibetan Plateau

    Science.gov (United States)

    Opitz, Stephan; Ramisch, Arne; Mischke, Steffen; Diekmann, Bernhard

    2013-10-01

    Sediments of a thermokarst system on the north-eastern Tibetan Plateau were studied to infer changes in the lacustrine depositional environment related to climatic changes since the early Holocene. The thermokarst pond with a length of 360 m is situated in a 14.5 × 6 km tectonically unaffected intermontane basin, which is underlain by discontinuous permafrost. A lake sediment core and bankside lacustrine onshore deposits were analysed. Additionally, fossil lake sediments were investigated, which document a former lake-level high stand. The sediments are mainly composed of marls with variable amounts of silt carbonate micrite, and organic matter. On the basis of sedimentological (grain size data), geochemical (XRF), mineralogical (XRD) and micropaleontological data (ostracods and chironomide assemblages) a reconstruction of a paleolake environment was achieved. Lacustrine sediments with endogenic carbonate precipitation suggest a lacustrine environment since at least 19.0 cal ka BP. However, because of relocation and reworking processes in the lake, the sediments did not provide distinct information about the ultimate formation of the lake. The high amount of endogenic carbonate suggests prolonged still-water conditions at about 9.3 cal ka BP. Ostracod shells and chironomid head capsules in fossil lake sediments indicate at least one former lake-level high stand, which were developed between the early and middle Holocene. From the late Holocene the area was possibly characterized by a lake-level decline, documented by a hiatus between lacustrine sediments and a reworked loess or loess-like horizon. After the lake-level decline and the following warming period, the area was affected by thermally-induced subsidence and a re-flooding of the basin because of thawing permafrost.

  9. The summer snow cover anomaly over the Tibetan Plateau and its association with simultaneous precipitation over the mei-yu-baiu region

    Science.gov (United States)

    Liu, Ge; Wu, Renguang; Zhang, Yuanzhi; Nan, Sulan

    2014-07-01

    The summer snow anomalies over the Tibetan Plateau (TP) and their effects on climate variability are often overlooked, possibly due to the fact that some datasets cannot properly capture summer snow cover over high terrain. The satellite-derived Equal-Area Scalable Earth grid (EASE-grid) dataset shows that snow still exists in summer in the western part and along the southern flank of the TP. Analysis demonstrates that the summer snow cover area proportion (SCAP) over the TP has a significant positive correlation with simultaneous precipitation over the mei-yu-baiu (MB) region on the interannual time scale. The close relationship between the summer SCAP and summer precipitation over the MB region could not be simply considered as a simultaneous response to the Silk Road pattern and the SST anomalies in the tropical Indian Ocean and tropical central-eastern Pacific. The SCAP anomaly has an independent effect and may directly modulate the land surface heating and, consequently, vertical motion over the western TP, and concurrently induce anomalous vertical motion over the North Indian Ocean via a meridional vertical circulation. Through a zonal vertical circulation over the tropics and a Kelvin wave-type response, anomalous vertical motion over the North Indian Ocean may result in an anomalous high over the western North Pacific and modulate the convective activity in the western Pacific warm pool, which stimulates the East Asia-Pacific (EAP) pattern and eventually affects summer precipitation over the MB region.

  10. Climate Change and Its Impact on the Eco-Environment of the Three-Rivers Headwater Region on the Tibetan Plateau, China

    Science.gov (United States)

    Jiang, Chong; Zhang, Linbo

    2015-01-01

    This study analyzes the impact of climate change on the eco-environment of the Three-Rivers Headwater Region (TRHR), Tibetan Plateau, China. Temperature and precipitation experienced sharp increases in this region during the past 57 years. A dramatic increase in winter temperatures contributed to a rise in average annual temperatures. Moreover, annual runoff in the Lancang (LRB) and Yangtze (YARB) river basins showed an increasing trend, compared to a slight decrease in the Yellow River Basin (YRB). Runoff is predominantly influenced by rainfall, which is controlled by several monsoon systems. The water temperature in the YRB and YARB increased significantly from 1958 to 2007 (p < 0.001), driven by air temperature changes. Additionally, owing to warming and wetting trends in the TRHR, the net primary productivity (NPP) and normalized difference vegetation index (NDVI) showed significant increasing trends during the past half-century. Furthermore, although an increase in water erosion due to rainfall erosivity was observed, wind speeds declined significantly, causing a decline in wind erosion, as well as the frequency and duration of sandstorms. A clear regional warming trend caused an obvious increasing trend in glacier runoff, with a maximum value observed in the 2000s. PMID:26404333

  11. Climate Change and Its Impact on the Eco-Environment of the Three-Rivers Headwater Region on the Tibetan Plateau, China.

    Science.gov (United States)

    Jiang, Chong; Zhang, Linbo

    2015-09-25

    This study analyzes the impact of climate change on the eco-environment of the Three-Rivers Headwater Region (TRHR), Tibetan Plateau, China. Temperature and precipitation experienced sharp increases in this region during the past 57 years. A dramatic increase in winter temperatures contributed to a rise in average annual temperatures. Moreover, annual runoff in the Lancang (LRB) and Yangtze (YARB) river basins showed an increasing trend, compared to a slight decrease in the Yellow River Basin (YRB). Runoff is predominantly influenced by rainfall, which is controlled by several monsoon systems. The water temperature in the YRB and YARB increased significantly from 1958 to 2007 (p changes. Additionally, owing to warming and wetting trends in the TRHR, the net primary productivity (NPP) and normalized difference vegetation index (NDVI) showed significant increasing trends during the past half-century. Furthermore, although an increase in water erosion due to rainfall erosivity was observed, wind speeds declined significantly, causing a decline in wind erosion, as well as the frequency and duration of sandstorms. A clear regional warming trend caused an obvious increasing trend in glacier runoff, with a maximum value observed in the 2000s.

  12. Land Use and Land Cover Change in the Qinghai Lake Region of the Tibetan Plateau and Its Impact on Ecosystem Services

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    Jian Gong

    2017-07-01

    Full Text Available Exploration of land use and land cover change (LULCC and its impacts on ecosystem services in Tibetan plateau is valuable for landscape and environmental conservation. In this study, we conduct spatial analysis on empirical land use and land cover data in the Qinghai Lake region for 1990, 2000, and 2010 and simulate land cover patterns for 2020. We then evaluate the impacts of LULCC on ecosystem service value (ESV, and analyze the sensitivity of ESV to LULCC to identify the ecologically sensitive area. Our results indicate that, from 1990 to 2010, the area of forest and grassland increased while the area of unused land decreased. Simulation results suggest that the area of grassland and forest will continue to increase and the area of cropland and unused land will decrease for 2010–2020. The ESV in the study area increased from 694.50 billion Yuan in 1990 to 714.28 billion Yuan in 2000, and to 696.72 billion Yuan in 2020. Hydrology regulation and waste treatment are the top two ecosystem services in this region. The towns surrounding the Qinghai Lake have high ESVs, especially in the north of the Qinghai Lake. The towns with high ESV sensitivity to LULCC are located in the northwest, while the towns in the north of the Qinghai Lake experienced substantial increase in sensitivity index from 2000–2010 to 2010–2020, especially for three regulation services and aesthetic landscape provision services.

  13. Land Use and Land Cover Change in the Qinghai Lake Region of the Tibetan Plateau and Its Impact on Ecosystem Services

    Science.gov (United States)

    Gong, Jian; Yang, Jianxin; Tang, Wenwu

    2017-01-01

    Exploration of land use and land cover change (LULCC) and its impacts on ecosystem services in Tibetan plateau is valuable for landscape and environmental conservation. In this study, we conduct spatial analysis on empirical land use and land cover data in the Qinghai Lake region for 1990, 2000, and 2010 and simulate land cover patterns for 2020. We then evaluate the impacts of LULCC on ecosystem service value (ESV), and analyze the sensitivity of ESV to LULCC to identify the ecologically sensitive area. Our results indicate that, from 1990 to 2010, the area of forest and grassland increased while the area of unused land decreased. Simulation results suggest that the area of grassland and forest will continue to increase and the area of cropland and unused land will decrease for 2010–2020. The ESV in the study area increased from 694.50 billion Yuan in 1990 to 714.28 billion Yuan in 2000, and to 696.72 billion Yuan in 2020. Hydrology regulation and waste treatment are the top two ecosystem services in this region. The towns surrounding the Qinghai Lake have high ESVs, especially in the north of the Qinghai Lake. The towns with high ESV sensitivity to LULCC are located in the northwest, while the towns in the north of the Qinghai Lake experienced substantial increase in sensitivity index from 2000–2010 to 2010–2020, especially for three regulation services and aesthetic landscape provision services. PMID:28754029

  14. Land Use and Land Cover Change in the Qinghai Lake Region of the Tibetan Plateau and Its Impact on Ecosystem Services.

    Science.gov (United States)

    Gong, Jian; Li, Jingye; Yang, Jianxin; Li, Shicheng; Tang, Wenwu

    2017-07-21

    Exploration of land use and land cover change (LULCC) and its impacts on ecosystem services in Tibetan plateau is valuable for landscape and environmental conservation. In this study, we conduct spatial analysis on empirical land use and land cover data in the Qinghai Lake region for 1990, 2000, and 2010 and simulate land cover patterns for 2020. We then evaluate the impacts of LULCC on ecosystem service value (ESV), and analyze the sensitivity of ESV to LULCC to identify the ecologically sensitive area. Our results indicate that, from 1990 to 2010, the area of forest and grassland increased while the area of unused land decreased. Simulation results suggest that the area of grassland and forest will continue to increase and the area of cropland and unused land will decrease for 2010-2020. The ESV in the study area increased from 694.50 billion Yuan in 1990 to 714.28 billion Yuan in 2000, and to 696.72 billion Yuan in 2020. Hydrology regulation and waste treatment are the top two ecosystem services in this region. The towns surrounding the Qinghai Lake have high ESVs, especially in the north of the Qinghai Lake. The towns with high ESV sensitivity to LULCC are located in the northwest, while the towns in the north of the Qinghai Lake experienced substantial increase in sensitivity index from 2000-2010 to 2010-2020, especially for three regulation services and aesthetic landscape provision services.

  15. Comparison of the Long-Range Climate Memory in Outgoing Longwave Radiation over the Tibetan Plateau and the Indian Monsoon Region

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    Zhongping Shen

    2017-01-01

    Full Text Available Based on the detrended fluctuation analysis (DFA method, scaling behaviors of the daily outgoing longwave radiation (OLR from 1979 to 2015 over the Tibetan Plateau (TP and the Indian Monsoon Region (IMR are analyzed. The results show that there is long-term memory for the OLR time series over the TP and IMR. The long-range memory behaviors of OLR over TP are stronger than those over IMR. The averaged values of the scaling exponents over TP and IMR are 0.71 and 0.64; the maximum values in the two regions are 0.81 and 0.75; the minimum values are 0.59 and 0.58. The maximum frequency counts for scaling exponents occur in the range of 0.625 and 0.675 both in TP and in IMR. The spatial distribution of the scaling exponents of the OLR sequence is closely related to the conditions of climatic high cloud cover in the two areas. The high cloud cover over TP is obviously less than that of IMR. In addition, the scaling behaviors of OLR over TP and IMR are caused by the fractal characteristics of time series, which is further proved by randomly disrupting the time series to remove trends and correlation.

  16. [Mediator effect analysis of the trait coping style on job stress and fatigue of the military personnel stationed in plateau and high cold region].

    Science.gov (United States)

    Zhang, J J; Jia, J M; Tao, N; Song, Z X; Ge, H; Jiang, Y; Tian, H; Qiu, E C; Tang, J H; Liu, J W

    2017-03-20

    Objective: To investigate the fatigue status of military personnel stationed in plateau and high cold region, and to analyze the mediator effect of trait coping style on job stress and fatigue. Methods: In October 2010, with the method of cluster random sampling survey, 531 military personnel stationed in plateau and high cold region were chosen as subject. The fatigue status were evaluated by the Chinese version multidimensional fatigue inventory (MFI-20) , job stress were evaluated by the Job Stress Survey (JSS) , and trait coping style were evaluated by the Trait Coping Style Questionnaire (TCSQ) . Results: According to the information of different population characteristics, mean rank of physical fatigue about the urban (town) group were higher than that of rural group (Z=-2.200, Pfatigue scores about the urban (town) group were higher than that of rural group (Z=-3.026, Pfatigue about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-4.045, Pfatigue about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-2.879, Pfatigue scores about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-3.647, Pfatigue scores were significant statistical difference among the military officers, sergeancy and soldier group (F=14.711, Pfatigue (r(s)=0.129) , reduced activity (r(s)=0.123) , reduced motivation (r(s)=0.149) and general fatigue (r(s)=0.174) respectively, the score of organizational support lack strength were positively correlated with the score of physical fatigue (r(s)=0.090) , reduced activity (r(s)=0.098) , reduced motivation (r(s)=0.099) and general fatigue (r(s)=0.130) respectively. The mediator effect of negative coping style on the job stress and fatigue was 0.013 (Pfatigue statuses of the urban (town) group and the up or equal 20-years old age group are poor, and the negative coping style plays mediator effect on the job

  17. Effects of Revegetation on Soil Organic Carbon Storage and Erosion-Induced Carbon Loss under Extreme Rainstorms in the Hill and Gully Region of the Loess Plateau

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    Yujin Li

    2016-04-01

    Full Text Available Background: The Loess Plateau, an ecologically vulnerable region, has long been suffering from serious soil erosion. Revegetation has been implemented to control soil erosion and improve ecosystems in the Loess Plateau region through a series of ecological recovery programs. However, the increasing atmospheric CO2 as a result of human intervention is affecting the climate by global warming, resulting in the greater frequency and intensity of extreme weather events, such as storms that may weaken the effectiveness of revegetation and cause severe soil erosion. Most research to date has evaluated the effectiveness of revegetation on soil properties and soil erosion of different land use or vegetation types. Here, we study the effect of revegetation on soil organic carbon (SOC storage and erosion-induced carbon loss related to different plant communities, particularly under extreme rainstorm events. Materials and methods: The erosion-pin method was used to quantify soil erosion, and soil samples were taken at soil depths of 0–5 cm, 5–10 cm and 10–20 cm to determine the SOC content for 13 typical hillside revegetation communities in the year of 2013, which had the highest rainfall with broad range, long duration and high intensity since 1945, in the Yanhe watershed. Results and discussion: The SOC concentrations of all plant communities increased with soil depth when compared with slope cropland, and significant increases (p < 0.05 were observed for most shrub and forest communities, particularly for natural ones. Taking the natural secondary forest community as reference (i.e., soil loss and SOC loss were both 1.0, the relative soil loss and SOC loss of the other 12 plant communities in 2013 ranged from 1.5 to 9.4 and 0.30 to 1.73, respectively. Natural shrub and forest communities showed greater resistance to rainstorm erosion than grassland communities. The natural grassland communities with lower SOC content produced lower SOC loss even

  18. Effects of Revegetation on Soil Organic Carbon Storage and Erosion-Induced Carbon Loss under Extreme Rainstorms in the Hill and Gully Region of the Loess Plateau.

    Science.gov (United States)

    Li, Yujin; Jiao, Juying; Wang, Zhijie; Cao, Binting; Wei, Yanhong; Hu, Shu

    2016-04-29

    The Loess Plateau, an ecologically vulnerable region, has long been suffering from serious soil erosion. Revegetation has been implemented to control soil erosion and improve ecosystems in the Loess Plateau region through a series of ecological recovery programs. However, the increasing atmospheric CO₂ as a result of human intervention is affecting the climate by global warming, resulting in the greater frequency and intensity of extreme weather events, such as storms that may weaken the effectiveness of revegetation and cause severe soil erosion. Most research to date has evaluated the effectiveness of revegetation on soil properties and soil erosion of different land use or vegetation types. Here, we study the effect of revegetation on soil organic carbon (SOC) storage and erosion-induced carbon loss related to different plant communities, particularly under extreme rainstorm events. The erosion-pin method was used to quantify soil erosion, and soil samples were taken at soil depths of 0-5 cm, 5-10 cm and 10-20 cm to determine the SOC content for 13 typical hillside revegetation communities in the year of 2013, which had the highest rainfall with broad range, long duration and high intensity since 1945, in the Yanhe watershed. The SOC concentrations of all plant communities increased with soil depth when compared with slope cropland, and significant increases (p soil loss and SOC loss were both 1.0), the relative soil loss and SOC loss of the other 12 plant communities in 2013 ranged from 1.5 to 9.4 and 0.30 to 1.73, respectively. Natural shrub and forest communities showed greater resistance to rainstorm erosion than grassland communities. The natural grassland communities with lower SOC content produced lower SOC loss even with higher soil loss, natural secondary forest communities produced higher SOC loss, primarily because of their higher SOC content, and the artificial R. pseudoacacia community with greater soil loss produced higher SOC loss. These results

  19. Direct radiative effects of dust aerosols emitted from the Tibetan Plateau on the East Asian summer monsoon – a regional climate model simulation

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    H. Sun

    2017-11-01

    Full Text Available While dust aerosols emitted from major Asian sources such as Taklimakan and Gobi deserts have been shown to have strong effect on Asian monsoon and climate, the role of dust emitted from Tibetan Plateau (TP itself, where aerosols can directly interact with the TP heat pump because of their physical proximity both in location and elevation, has not been examined. This study uses the dust-coupled RegCM4.1 regional climate model (RCM to simulate the spatiotemporal distribution of dust aerosols originating within the TP and their radiative effects on the East Asian summer monsoon (EASM during both heavy and light dust years. Two 20-year simulations with and without the dust emission from TP showed that direct radiative cooling in the mid-troposphere induced by the TP locally produced dust aerosols resulted in an overall anticyclonic circulation anomaly in the low troposphere centered over the TP region. The northeasterly anomaly in the EASM region reduces its strength considerably. The simulations found a significant negative correlation between the TP column dust load produced by local emissions and the corresponding anomaly in the EASM index (r = −0.46. The locally generated TP dust can cause surface cooling far downstream in Bohai Gulf and the China–North Korea border area through stationary Rossby wave propagation. Although dust from within TP (mainly Qaidam Basin is a relatively small portion of total Asian aerosols, its impacts on Asian monsoon and climate seems disproportionately large, likely owning to its higher elevation within TP itself.

  20. The exploitation of obsidian in the Central Plateau of Santa Cruz, Argentina: Results from La María and Cerro Tres Tetas and a regional perspective

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    Manuel Enrique Cueto

    2016-09-01

    Results from this work strengthen the idea that the groups which lived in the Central Plateau knew about and exploited an obsidian source known as Pampa del Asador. A raise in the use of this raw material throughout time is recorded, reaching its peak in the late Holocene. We identified two different moments in the exploitation of obsidian at the regional level. During the final Pleistocene and early Holocene, obsidian would not have played a relevant role in the organization of technology. Production sequences indicate that tools probably were entered to the sites already manufactured. During the middle and late Holocene nodules and cores could have been brought into the sites. The strategies involved in their reduction are in broad terms similar to those implemented with local raw materials; there is no evidence that obsidian had more value in any way. On the other hand, it is also not possible to state that there was just an eventual exploitation of this raw material. We believe that obsidian was acquired during mobility circuits which enabled the contact between different groups.

  1. The Fragmented Manihiki Plateau - Key Region for Understanding the Break-up of the "Super" Large Igneous Province Ontong Java Nui

    Science.gov (United States)

    Hochmuth, K.; Gohl, K.; Uenzelmann-Neben, G.; Werner, R.

    2014-12-01

    The Manihiki Plateau of the western Pacific is one of the world - wide greatest Large Igneous Province (LIP) on oceanic crust. It is assumed that the Manihiki Plateau was emplaced as the centerpiece of the "Super-LIP" Ontong Java Nui by multiple volcanic phases during the Cretaceous Magnetic Quiet Period. The subsequent break-up of Ontong Java Nui led to fragmentation of the Manihiki Plateau into three sub-plateaus, which all exhibit individual relicts of the "Super-LIP" break-up. We examine two deep crustal seismic refraction/wide-angle reflection profiles crossing the two largest sub-plateaus of the Manihiki Plateau, the Western Plateaus and the High Plateau. Modeling of P- and S-wave velocities reveals surprising differences in the crustal structure between the two sub-plateaus. Whereas the High Plateau shows a constant crustal thickness of 20 km, relicts of multiple volcanic phases and break-up features at its margins, the model of the Western Plateaus reveals a crustal thickness decreasing from 17 km to only 9 km. There is only little evidence of secondary phases of volcanic activity. The main upper crustal structure on the Western Plateaus consists of fault systems and sedimentary basins. We infer that the High Plateau experienced phases of strong secondary volcanism, and that tectonic deformation was limited to its edges. The Western Plateaus, on the contrary, were deformed by crustal stretching and underwent only little to no secondary volcanism. This indicates that the two main sub-plateaus of the Manihiki Plateau experienced a different geological history and have played their individual parts in the break-up history of Ontong Java Nui.

  2. Regional variations of crustal thickness along the eastern edge of the Tibetan plateau and their tectonic implications

    Science.gov (United States)

    Kang, D.; YU, C.; TAO, K.; Chen, W.; Liu, Q.; Chen, J.; Zheng, X.; Ning, J.

    2011-12-01

    Using data from a massive array of xyz broadband seismographs deployed in the Sichuan-Yunnan Region, southwestern China, we applied the method of Virtual Deep Seismic Sounding (VDSS; Tseng et al., 2009) to investigate regional variations in crustal thickness near the eastern edge of Tibet. VDSS takes advantage of the deep-penetrating power of teleseismic waves and is very robust in determining the overall thickness of crust. It uses SV-to-P conversion off the free surface as a virtual source near each receiver to generate strong, post-critical reflections such as the SsPmp phase off the Moho. Preliminary results indicate that there are no abrupt changes in crustal thickness beneath major fault zones such as Longmen Shan fold-and-thrust belt (where the devastating Wenchuan earthquake sequence occurred in 2008), the largely strike-slip Xianshuihe fault system, and the largely strike-slip Anninghe fault zone. When compared with predictions from Airy isostasy, crustal thicknesses of the stable Sichuan basin (35 km to 44 km) and of the southern Chuan-Dian block (about 50 km to 60 km), fall within expected ranges. However, crustal thicknesses beneath the marginal area of northern Chuan-Dian (40 km to 47 km) block and the marginal area of Songpan-Ganze terrane (about 30 km) are much thinner than expected (by 15 km to 30 km), calling for active tectonic support from the mantle lithosphere. Tseng, T.-L., W.-P. Chen, et al. Northward thinning of Tibetan crust revealed by virtual seismic profiles. Geophysical Research Letters, 2009, 36(24): L24304.

  3. Impacts of Summer Extreme Precipitation Events on the Hydrothermal Dynamics of the Active Layer in the Tanggula Permafrost Region on the Qinghai-Tibetan Plateau

    Science.gov (United States)

    Zhu, Xiaofan; Wu, Tonghua; Li, Ren; Xie, Changwei; Hu, Guojie; Qin, Yanhui; Wang, Weihua; Hao, Junming; Yang, Shuhua; Ni, Jie; Yang, Cheng

    2017-11-01

    The characteristics of long-term variation for extreme precipitation events were analyzed at the Tanggula site in the continuous permafrost regions of the Qinghai-Tibetan Plateau (QTP). In addition, the impacts of extreme precipitation events in summer on soil thermal-moisture dynamics were also investigated. The results showed that local extreme precipitation indices fluctuated significantly and that the trend magnitudes of local very wet days (R95p), annual total wet-day precipitation (PRCPTOT), number of heavy precipitation days (R10mm), maximum length of dry spell (CDD), and simple daily intensity index (SDII) were larger than those of the western QTP, other regions of China, and even the global average. The freeze-thaw cycling in the local active layer occurred from October to the next September during 2006 to 2014. The influence of extreme precipitation event in summer on local soil hydrothermal conditions could reach soil depths up to 105 cm or so, and these were more pronounced than with light or moderate precipitation events. Soil temperature reacted more promptly to local extreme precipitation events than did soil moisture. The rate at which local soil temperature fell after an extreme precipitation event was greater than the rate of increasing temperature on nonprecipitation days. Moreover, the amount of precipitation received during extreme precipitation events had a greater effect on local soil moisture and temperature than duration time for these events. Consecutive extreme precipitation events with a longer duration time did not necessarily to have a greater effect than a single precipitation event with a shorter duration. Finally, the thawing process of active layer and local water migration modes could also affect the response of soil hydrothermal conditions to an extreme precipitation event to a large extent.

  4. [Effects of climate warming on oil flax growth and water use efficiency in semi-arid region of Loess Plateau, Northwest China].

    Science.gov (United States)

    Yao, Yu-bi; Wang, Run-yuan; Yang, Jin-hu; Xiao, Guo-ju; Zhang, Xiu-yun; Yue, Ping

    2011-10-01

    By using the site-specific observation data of oil flax growth and related meteorological records in semi-arid region of Loess Plateau, this paper studied the effects of climate change on the oil flax growth, and analyzed the relationships between the oil flax water use efficiency and meteorological condition. In this region, the annual precipitation displayed a decreasing trend, and its climatic trend rate was -15.80 mm (10 a)(-1), with an annual periodic change of 3 a and 6 a, whereas the annual air temperature had an increasing trend, and its climatic trend rate was 0.36 degrees C (10 a)(-1). In crop growth period, the aridity index displayed a marked increasing trend, its climatic trend rate was 0.12 (10 a)(-1), and the aridity tendency was more obvious from the beginning of 1990s to the year 2009. From sowing to maturation, oil flax needed 120-150 d, 1700-2100 degrees C d of > or = 0 degrees C accumulated temperature, 200-250 mm precipitation, and 1000-1300 h sunshine hours. The main meteorological factors affecting the oil flax growth in the region were air temperature and precipitation. The increase of air temperature shortened the prophase vegetative growth stage, whereas the increase of air temperature and the decrease of precipitation extended the reproductive growth stage, causing the extension of the whole growth period of the oil flax. The air temperature in the oil flax whole growth period except at seeding stage and maturing stage had negative effect on the yield formation, being more obvious at squaring stage, whereas the precipitation in the whole growth period except at blooming stage had positive effect on the yield formation, being more obvious at seeding stage. The water use efficiency of the oil flax was significantly positively correlated with the air temperature and sunshine hours at seeding stage as well as the aridity index from squaring stage to maturing stage, and negatively correlated with the precipitation from squaring stage to

  5. Application of a Geographic Information System for regridding a ground-water flow model of the Columbia Plateau Regional Aquifer System, Walla Walla River basin, Oregon-Washington

    Science.gov (United States)

    Darling, M.E.; Hubbard, L.E.

    1994-01-01

    Computerized Geographic Information Systems (GIS) have become viable and valuable tools for managing,analyzing, creating, and displaying data for three-dimensional finite-difference ground-water flow models. Three GIS applications demonstrated in this study are: (1) regridding of data arrays from an existing large-area, low resolution ground-water model to a smaller, high resolution grid; (2) use of GIS techniques for assembly of data-input arrays for a ground-water model; and (3) use of GIS for rapid display of data for verification, for checking of ground-water model output, and for the cre.ation of customized maps for use in reports. The Walla Walla River Basin was selected as the location for the demonstration because (1) data from a low resolution ground-water model (Columbia Plateau Regional Aquifer System Analysis [RASA]) were available and (2) concern for long-term use of water resources for irrigation in the basin. The principal advantage of regridding is that it may provide the ability to more precisely calibrate a model, assuming chat a more detailed coverage of data is available, and to evaluate the numerical errors associated with a particular grid design.Regridding gave about an 8-fold increase in grid-node density.Several FORTRAN programs were developed to load the regridded ground-water data into a finite-difference modular model as model-compatible input files for use in a steady-state model run.To facilitate the checking and validating of the GIS regridding process, maps and tabular reports were produced for each of eight ground-water parameters by model layer. Also, an automated subroutine that was developed to view the model-calculated water levels in cross-section will aid in the synthesis and interpretation of model results.

  6. Distribution of branched glycerol dialkyl glycerol tetraethers in surface soils of the Qinghai–Tibetan Plateau: implications of brGDGTs-based proxies in cold and dry regions

    Directory of Open Access Journals (Sweden)

    S. Ding

    2015-06-01

    Full Text Available The methylation index of branched tetraethers (MBT and cyclization ratio of branched tetraethers (CBT based on the distribution of branched glycerol dialkyl glycerol tetraethers (brGDGT are useful proxies for the reconstruction of mean annual air temperature (MAT and soil pH. Recently, a series of 6-methyl brGDGTs were identified which were previously co-eluted with 5-methyl brGDGTs. However, little is known about 6-methyl brGDGTs in the Qinghai–Tibetan Plateau (QTP, a critical region of the global climate system. Here, we analyze 30 surface soils covering a large area of the QTP, among which 6-methyl brGDGTs were the most abundant components (average 53 ± 17% of total brGDGT. The fractional abundance of 6-methyl brGDGTs showed a good correlation with soil pH, while the global MBT'5ME calibration overestimates MAT in the QTP. We therefore proposed a MBT5/6 index including both 5- and 6-methyl brGDGTs, presenting a strong correlation with MAT in QTP: MAT = −20.14 + 39.51 × MBT5/6 (n = 27, r2 = 0.82; RMSE = 1.3 °C. Another index, namely IBT (isomerization of branched tetraether, based on carbon skeleton isomerization of the 5-methyl to 6-methyl brGDGTs, is dependent on soil pH: pH = 6.77 − 1.56 × IBT (n = 27; r2 = 0.74, RMSE = 0.32. Our study suggests that changing the position of methyl group of brGDGTs may be another mechanism for some soil bacteria to adapt to the ambient pH change in addition to the well-known cyclization.

  7. Elemental carbon and polycyclic aromatic compounds in a 150-year sediment core from Lake Qinghai, Tibetan Plateau, China: influence of regional and local sources and transport pathways.

    Science.gov (United States)

    Han, Y M; Wei, C; Bandowe, B A M; Wilcke, W; Cao, J J; Xu, B Q; Gao, S P; Tie, X X; Li, G H; Jin, Z D; An, Z S

    2015-04-07

    Elemental carbon (EC) and polycyclic aromatic compounds (PACs) are potential proxies for the reconstruction of change in human activities and the origin of air masses in historic times. In this study, the historic deposition of char and soot (the two subtypes of EC) and PACs in a 150-year sediment core from different topographic subbasins of Lake Qinghai on the Qinghai Tibetan Plateau (QTP) were reconstructed. The objective was to explore how the variations in the concentrations of EC and PACs, in the ratios of char to soot and of oxygenated polycyclic aromatic hydrocarbons (OPAHs) to parent PAHs, and in the composition of the PAC mixtures reflect historical changes in climate and human activity and the origin of air masses arriving at the QTP. The deposition fluxes of soot in the different subbasins were similar, averaging 0.18 (range of 0.15-0.25) and 0.16 (0.13-0.23) g m(-2) year(-1), respectively, but they varied for char (averaging 0.11 and 0.22 g m(-2) year(-1), respectively), suggesting ubiquitous atmospheric deposition of soot and local river inputs of char. The different vertical distributions of the char/soot ratios in the different subbasins can be interpreted in terms of the different transport mechanisms of char and soot. An abrupt increase in soot concentrations since 1980 coincides with results from the QTP ice cores that were interpreted to be indicative of soot transport from South Asia. Similar concentration patterns of PAHs with soot and 9,10-anthraquinone/anthracene (9,10-AQ/ANT) ratios all >2.0 suggest regional PAC sources. Increasing PAH/soot ratios and decreasing 9,10-AQ/ANT ratios since the beginning of the 1970s indicate increasing local emissions. The historical trends of these diagnostic ratios indicate an increase in the fossil-fuel contribution since the beginning of the 1970s. The increase of perylene concentrations with increasing core depth and the ratio of perylene to its penta-aromatic isomers indicate that perylene originates

  8. Evaluating the Effects of Government Policy and Drought from 1984 to 2009 on Rangeland in the Three Rivers Source Region of the Qinghai-Tibet Plateau

    Directory of Open Access Journals (Sweden)

    Qingshui Lu

    2017-06-01

    Full Text Available The Three Rivers Source Region of the Qinghai-Tibet Plateau is a key area that has extensive impacts on much of the population and economy of China as well as several Southeast Asian countries. The rangeland in this area has undergone degradation, the driving factors of which have been extensively investigated in previous studies. However, the effect of policy on rangeland was not analyzed by subdividing the study period according to the timing of the rangeland policies. The role of dry conditions during the process of degradation has not been studied. Therefore, the period from 1984 to 2009 was subdivided into five periods according to the timing of the relevant government policies based on long-term field investigation. The mean annual normalized difference vegetation index (NDVI and its relationship to dry conditions, policy, temperature, precipitation, and moisture index were analyzed for the five periods. According to our analysis, dry conditions mainly occurred in non-vegetation-growing months, and they did not affect the status of the rangeland. The privatization of rangeland and livestock caused the number of livestock to increase, resulting in a decrease in the mean annual NDVI from 1984 to 1993. The policies of “Green-to-Grain” and eco-migration caused livestock numbers to decrease and the NDVI to increase after 1994. Physical factors such as temperature, precipitation, and moisture also affected the status of the rangeland. Increased temperature had positive effects on rangeland in most areas, but its effect was offset by increased numbers of livestock from 1984 to 1993. Precipitation had positive effects only in drier areas in which the precipitation in the vegetation-growing months was less than 400 mm. In general, the policies of “Green-to-Grain” and eco-migration improved the status of rangeland, and helped improve sustainable use of the rangeland. The methods used in this study could be applied to other case studies of

  9. Extreme UV index and solar exposures at Plateau Rosà (3500 m a.s.l.) in Valle d’Aosta Region, Italy

    Energy Technology Data Exchange (ETDEWEB)

    Casale, Giuseppe R. [Sapienza Università di Roma, Department of Physics, p.le A. Moro 2, I-00185 Rome (Italy); Siani, Anna Maria, E-mail: annamaria.siani@uniroma1.it [Sapienza Università di Roma, Department of Physics, p.le A. Moro 2, I-00185 Rome (Italy); Diémoz, Henri [Sapienza Università di Roma, Department of Physics, p.le A. Moro 2, I-00185 Rome (Italy); ARPA Valle d' Aosta (Aosta Valley Regional Environmental Protection Agency), Saint-Christophe-Aosta (Italy); Agnesod, Giovanni [ARPA Valle d' Aosta (Aosta Valley Regional Environmental Protection Agency), Saint-Christophe-Aosta (Italy); Parisi, Alfio V. [University of Southern Queensland, Toowoomba 4350 Australia (Australia); Colosimo, Alfredo [Sapienza Università di Roma, Department SAIMLAL, Via A. Borelli 50, I-00185 Rome (Italy)

    2015-04-15

    The purpose of this study is to assess personal exposures of skiers at the Alpine site of Plateau Rosà (45.9°N, 7.7°E, 3500 m a.s.l.), in the Valle d'Aosta region, Italy. The campaign was carried out on July 12th, 2011 during the summer ski season. A peak UVI value of 12.3, among the highest in Europe, was recorded on that day. Personal exposures (PE) were quantified using both polysulphone (PS) and poly-dimethyl phenylene oxide (PPO) dosimeters attached vertically to the cap because it is representative of the vertically oriented face of skiers. Exposure ratio (ER) defined as the ratio between PE and the corresponding ambient dose (i.e. erythemally weighted dose received by a horizontal surface) measured by a broad-band radiometer during the same exposure time of the subjects, was used to compare the results with previous studies. Skin color was also measured on the inner upper arm and on the cheek and differences in ITA (Individual Typology Angle) and a* (redness) values before and after exposure, were statistically analyzed. During the exposure period, the median PE (with PS) was 1.47 kJ m{sup −2} and that obtained by PPO was 1.15 kJ m{sup −2}. The median of the ERs was 0.65 (min: 0.50, max: 0.83) considering the cumulative PS exposure and 0.46 (min: 0.29, max: 0.95) for PPO. An increase in ITAs on the exposed site (i.e. the skin became lighter) was observed after exposure. These results indicate that: a) for some skiers, the exposures were similar to those received on the horizontal plane; and b) the targeted population showed exposures above the occupational threshold limit value (TLV) defined by ICNIRP; c) the use of physical sunscreens which tend to leave a white cast, might have reduced skin color change. Nevertheless possible visible sun-induced skin-color changes could be observed after longer time intervals after exposure. - Highlights: • PS and PPO dosimeters measure UV exposures over short/prolonged periods, respectively. • Large UV

  10. Diurnal and Seasonal Variations in the Net Ecosystem CO2 Exchange of a Pasture in the Three-River Source Region of the Qinghai-Tibetan Plateau.

    Directory of Open Access Journals (Sweden)

    Bin Wang

    Full Text Available Carbon dioxide (CO2 exchange between the atmosphere and grassland ecosystems is very important for the global carbon balance. To assess the CO2 flux and its relationship to environmental factors, the eddy covariance method was used to evaluate the diurnal cycle and seasonal pattern of the net ecosystem CO2 exchange (NEE of a cultivated pasture in the Three-River Source Region (TRSR on the Qinghai-Tibetan Plateau from January 1 to December 31, 2008. The diurnal variations in the NEE and ecosystem respiration (Re during the growing season exhibited single-peak patterns, the maximum and minimum CO2 uptake observed during the noon hours and night; and the maximum and minimum Re took place in the afternoon and early morning, respectively. The minimum hourly NEE rate and the maximum hourly Re rate were -7.89 and 5.03 μmol CO2 m-2 s-1, respectively. The NEE and Re showed clear seasonal variations, with lower values in winter and higher values in the peak growth period. The highest daily values for C uptake and Re were observed on August 12 (-2.91 g C m-2 d-1 and July 28 (5.04 g C m-2 day-1, respectively. The annual total NEE and Re were -140.01 and 403.57 g C m-2 year-1, respectively. The apparent quantum yield (α was -0.0275 μmol μmol-1 for the entire growing period, and the α values for the pasture's light response curve varied with the leaf area index (LAI, air temperature (Ta, soil water content (SWC and vapor pressure deficit (VPD. Piecewise regression results indicated that the optimum Ta and VPD for the daytime NEE were 14.1°C and 0.65 kPa, respectively. The daytime NEE decreased with increasing SWC, and the temperature sensitivity of respiration (Q10 was 3.0 during the growing season, which was controlled by the SWC conditions. Path analysis suggested that the soil temperature at a depth of 5 cm (Tsoil was the most important environmental factor affecting daily variations in NEE during the growing season, and the photosynthetic photon

  11. [Seasonal characteristics of soil respiration and affecting factors under typical vegetations in the water-wind erosion crisscross region of the Loess Plateau].

    Science.gov (United States)

    Xie, Hui-Hui; Fan, Jun; Qi, Li-Bin; Hao, Ming-De

    2010-12-01

    By the soil respiration system, the characteristics of soil respiration were investigated to explore the correlations between soil respiration and soil temperature, soil water and soil nutrient under different land use patterns in the water-wind erosion crisscross region of the Loess Plateau. The results indicated that the seasonal changing characteristics of soil respiration were distinguished significantly among different vegetations, and soil water content and temperature were the main influencing factors. Soil respiration seasonal changing ranges, such as bare land, crop land, Medicago sativa land, Caragana korshinskii land, abandoned wild grass land, Stipa bungeana land, wild grass land, degraded Medicago sativa land, sloping Medicago sativa land, sloping abandoned wild grass land, sloping crop land and terraced crop land, were 0.32-0.82, 0.41-2.83, 0.74-2.81, 0.76-3.07, 0.67-2.79, 0.51-2.12, 0.56-2.05, 0.59-1.66, 0.42-2.09, 0.31-1.86, 0.32-1.93 and 0.41-3.17 micromol x (m2 x s)(-1). Comparing seasonal changing magnitudes of soil respiration, crop land was the biggest (167% - 203%), abandoned wild grass land (117% -154%), Caragana korshinskii land (134%), Stipa bungeana land (129%), Medicago sativa land (119%-120%) and bare land (94%) followed crop land. The smallest was degraded Medicago sativa land (92%). Bare land and degraded Medicago sativa land had small seasonal variation during the study period. Monthly average values of soil carbon flux (soil respiration) of Medicago sativa land and Caragana korshinskii land were maximal, but the maximum values under crop land were observed in July and August. Besides Q10 of crop land was also maximal, which reached 1.86. There were significant correlations between soil respiration and soil organic matter and available K. Moreover, soil respiration was affected by soil organic matter and total nitrogen in July and August when the water and heat condition were plentiful, but soil ammonium nitrogen had negative impact

  12. [Effects of land use change on soil active organic carbon in deep soils in Hilly Loess Plateau region of Northwest China].

    Science.gov (United States)

    Zhang, Shuai; Xu, Ming-Xiang; Zhang, Ya-Feng; Wang, Chao-Hua; Chen, Gai

    2015-02-01

    Response of soil active organic carbon to land-use change has become a hot topic in current soil carbon and nutrient cycling study. Soil active organic carbon distribution characteristics in soil profile under four land-use types were investigated in Ziwuling forest zone of the Hilly Loess Plateau region. The four types of land-use changes included natural woodland converted into artificial woodland, natural woodland converted into cropland, natural shrubland converted into cropland and natural shrubland converted into revegetated grassland. Effects of land-use changes on soil active organic carbon in deep soil layers (60-200 cm) were explored by comparison with the shallow soil layers (0-60 cm). The results showed that: (1) The labile organic carbon ( LOC) and microbial carbon (MBC) content were mainly concentrated in the shallow 0-60 cm soil, which accounted for 49%-66% and 71%-84% of soil active organic carbon in the profile (0-200 cm) under different land-use types. Soil active organic carbon content in shallow soil was significantly varied for the land-use changes types, while no obvious difference was observed in soil active organic carbon in deep soil layer. (2) Land-use changes exerted significant influence on soil active organic carbon, the active organic carbon in shallow soil was more sensitive than that in deep soil. The four types of land-use changes, including natural woodland to planted woodland, natural woodland to cropland, natural shrubland to revegetated grassland and natural shrubland to cropland, LOC in shallow soil was reduced by 10%, 60%, 29%, 40% and LOC in the deep layer was decreased by 9%, 21%, 12%, 1%, respectively. MBC in the shallow soil was reduced by 24% 73%, 23%, 56%, and that in the deep layer was decreased by 25%, 18%, 8% and 11%, respectively. (Land-use changes altered the distribution ratio of active organic carbon in soil profile. The ratio between LOC and SOC in shallow soil increased when natural woodland and shrubland were

  13. Differences in atmospheric heat source between the Tibetan Plateau-South Asia region and the southern Indian Ocean and their impacts on the Indian summer monsoon outbreak

    Science.gov (United States)

    Zhang, Yiwei; Fan, Guangzhou; Hua, Wei; Zhang, Yongli; Wang, Bingyun; Lai, Xin

    2017-06-01

    In this paper, the NCEP-NCAR daily reanalysis data are used to investigate the characteristics of the atmospheric heat source/sink (AHSS) over South Asia (SA) and southern Indian Ocean (SIO). The thermal differences between these two regions and their influence on the outbreak of the Indian summer monsoon (ISM) are explored. Composite analysis and correlation analysis are applied. The results indicate that the intraseasonal variability of AHSS is significant in SA but insignificant in the SIO. Large inland areas in the Northern Hemisphere still behave as a heat sink in March, similar to the situation in winter. Significant differences are found in the distribution of AHSS between the ocean and land, with distinct land-ocean thermal contrast in April, and the pattern presents in the transitional period right before the ISM onset. In May, strong heat centers appear over the areas from the Indochina Peninsula to the Bay of Bengal and south of the Tibetan Plateau (TP), which is a typical pattern of AHSS distribution during the monsoon season. The timing of SA-SIO thermal difference turning positive is about 15 pentads in advance of the onset of the ISM. Then, after the thermal differences have turned positive, a pre-monsoon meridional circulation cell develops due to the near-surface heat center and the negative thermal contrast center, after which the meridional circulation of the ISM gradually establishes. In years of early (late) conversion of the SA-SIO thermal difference turning from negative to positive, the AHSS at all levels over the TP and SIO converts later (earlier) than normal and the establishment of the ascending and descending branches of the ISM's meridional circulation is later (earlier) too. Meanwhile, the establishment of the South Asian high over the TP is later (earlier) than normal and the conversion of the Mascarene high from winter to summer mode occurs anomalously late (early). As a result, the onset of the ISM is later (earlier) than normal

  14. Factors Controlling Pre-Columbian and Early Historic Maize Productivity in the American Southwest, Part 2: The Chaco Halo, Mesa Verde, Pajarito Plateau/Bandelier, and Zuni Archaeological Regions

    Science.gov (United States)

    Benson, L.V.

    2011-01-01

    Chemical and nutrient analyses of 471 soil samples from 161 sites within four archaeological regions (Pajarito Plateau/Bandelier, Zuni, Mesa Verde, and the Chaco Halo) were combined with historical climate data in order to evaluate the agricultural productivity of each region. In addition, maize productivity and field-life calculations were performed using organic-nitrogen (N) values from the upper 50 cm of soil in each region and a range (1-3%/year) of N-mineralization rates. The endmember values of this range were assumed representative of dry and wet climate states. With respect to precipitation and heat, the Pajarito Plateau area has excellent agricultural potential; the agricultural potentials of the Zuni and Mesa Verde regions are good; and the agricultural potential of the Chaco Halo is poor. Calculations of N mineralization and field life indicate that Morfield Valley in Mesa Verde should be able to provide 10 bu/ac of maize for decades (without the addition of N) when organic N-mineralization rates exceed 2%. Productivity and field-life potential decrease in the following order: Zuni, Mesa Verde, Bandelier, Chaco Halo. The Chaco Halo is very unproductive; e. g., 10 bushels per acre can be achieved within the Halo only from soils having the highest organic N concentration (third quartile) and which undergo the highest rate (3%) of N mineralization. ?? 2010 US Government.

  15. Taxocenose de serpentes no Planalto Médio do Rio Grande do Sul, Brasil Taxocenosis of snakes in the middle plateau region of Rio Grande do Sul, Brazil

    Directory of Open Access Journals (Sweden)

    Noeli Zanella

    2006-03-01

    Full Text Available Este trabalho foi desenvolvido na Fazenda da Brigada (28º14'39"S, 52º14'42"W, Passo Fundo, Planalto Médio do Rio Grande do Sul, e teve como objetivo contribuir com informações sobre riqueza, abundância de serpentes e comparação entre os métodos de amostragem. O estudo foi desenvolvido em duas áreas, floresta e campo, no período de janeiro de 2001 a março de 2003. Para a coleta de dados foram utilizados os seguintes métodos: procura limitada por tempo (PLT, encontros ocasionais por terceiros (EOT, encontros ocasionais pela equipe (EOE e armadilhas de interceptação e queda (AQ. Com a utilização dos quatro métodos foi possível registrar 19 espécies de serpentes, distribuídas em três famílias (Colubridae, Elapidae e Viperidae e coletar 284 indivíduos, sendo 128 por EOT, 36 por PLT, 112 por AQ e 8 por EOE. Utilizando todos os métodos, as três espécies mais abundantes foram: Thamnodynastes strigatus (Günther, 1858 (16,9%, Echinanthera cyanopleura (Cope, 1885 (15,2% e Bothrops alternatus Duméril, Bibron & Duméril, 1854 (13,4%. O estudo dessa taxocenose revela importantes características da ecologia de serpentes e poderá subsidiar futuros estudos de conservação para a área.The present study was conducted on the Brigada Farm (28º14'39"S, 52º14'42"W, Passo Fundo, middle plateau region of Rio Grande do Sul. The objective of the study was to provide data regarding the richness and abundance of snakes and to compare sampling methods. The study was carried out in two areas, i.e., forest and field, between January 2001 and March 2003. Data were collected using the following methods: time-constrained search (TCS, occasional encounters by local collectors (OEC, occasional encounters by the team (OET, and by pitfall traps (PT. Using the four methods, 19 snake species belonging to three families (Colubridae, Elapidae and Viperidae were recorded, and 284 individuals were collected, including 128 by OEC, 36 by TCS, 112 by PT, and

  16. Quaternary erosion and cosmic-ray-exposure history derived from 10Be and 26Al produced in situ—An example from Pajarito plateau, Valles caldera region

    Science.gov (United States)

    Albrecht, Achim; Herzog, Gregory F.; Klein, Jeffrey; Dezfouly-Arjomandy, Bijan; Goff, Fraser

    1993-06-01

    10Be and 26Al concentrations measured by accelerator mass spectrometry in 20 samples of quartz separated from rhyolitic volcanic ash-flow tuffs collected on the Pajarito plateau of the Valles caldera, New Mexico, were used to model time-integrated erosion rates and cosmic ray-exposure histories. The model erosion rates determined for different stratigraphic units within the Tshirege member, upper Bandelier Tuff, vary from 0.1 cm/ka for the resistant unit to 1.1 cm/ka for the softer unit. Intermediate erosion rates are thought to indicate earlier age cover by post-tuff lithologies of different hardness. The geographic distribution of these intermediate rates allows an approximate determination of the extent of material now gone (stratigraphic ghosts). Periods of burial can be determined from 26Al/10Be ratios. For the Pajarito plateau, burial most likely resulted from cover by soil and sediment held in place by vegetation. Our data allow us to model the duration and extent of thick forest cover, which today exists only at higher altitudes.

  17. The Pajarito Plateau: A bibliography

    Science.gov (United States)

    Mathien, Frances Joan; Steen, Charlie R.; Allen, Craig D.

    1993-01-01

    This bibliography is the result of two initially independent projects. As the consulting archaeologist at Los Alamos National Laboratory (LANL), Charlie R. Steen collected entries at the suggestion of the staff of the Environmental Surveillance Group of the Health, Safety, and Environmental Division, HSE-8. The primary purpose was to aid the staff in evaluating cultural resources on LANL lands. In addition to works that related to the archaeology and history of the area, Steen included notations of a few books and articles in other fields such as geology and natural history. It was hoped that they also would be of value to other organizations and to students of past human activities on the Pajarito Plateau.At the same time, the National Park Service (NPS) was planning a major survey of Bandelier National Monument (BNM). As part of this plan, the author was asked to prepare a background document that described research previously carried out in the area, including an annotated bibliography. Although the survey would be limited to the park boundaries, the larger Pajarito Plateau is a more logical study area from physiographic, environmental, and cultural perspectives; hence the focus was on this larger region. Mathien (1986) also included some references to natural resources studies, particularly those initiated by NPS within Bandelier National Monument.Both bibliographies were made available to Colleen Olinger and Beverly Larson of the Health and Environmental Services Group at Los Alamos. They realized that while neither was complete, each included entries missing from the other. Larson suggested the two bibliographies be combined. (At this time, Craig Allen was studying the landscape of the Jemez Mountains [Allen 1984c, 1989]. His investigations included much detailed information on natural resource studies and were added in 1991 and 1992.)To limit the scope of their work, Steen and Mathien had chosen their parameter: the Pajarito Plateau. Geographically, the

  18. The Pajarito Plateau: a bibliography

    Science.gov (United States)

    Mathien, Frances Joan; Steen, Charlie R.; Allen, Craig D.

    1993-01-01

    This bibliography is the result of two initially independent projects. As the consulting archaeologist at Los Alamos National Laboratory (LANL), Charlie R. Steen collected entries at the suggestion of the staff of the Environmental Surveillance Group of the Health, Safety, and Environmental Division, HSE-8. The primary purpose was to aid the staff in evaluating cultural resources on LANL lands. In addition to works that related to the archaeology and history of the area, Steen included notations of a few books and articles in other fields such as geology and natural history. It was hoped that they also would be of value to other organizations and to students of past human activities on the Pajarito Plateau.At the same time, the National Park Service (NPS) was planning a major survey of Bandelier National Monument (BNM). As part of this plan, the author was asked to prepare a background document that described research previously carried out in the area, including an annotated bibliography. Although the survey would be limited to the park boundaries, the larger Pajarito Plateau is a more logical study area from physiographic, environmental, and cultural perspectives; hence the focus was on this larger region. Mathien (1986) also included some references to natural resources studies, particularly those initiated by NPS within Bandelier National Monument.Both bibliographies were made available to Colleen Olinger and Beverly Larson of the Health and Environmental Services Group at Los Alamos. They realized that while neither was complete, each included entries missing from the other. Larson suggested the two bibliographies be combined. (At this time, Craig Allen was studying the landscape of the Jemez Mountains [Allen 1984c, 1989]. His investigations included much detailed information on natural resource studies and were added in 1991 and 1992.)To limit the scope of their work, Steen and Mathien had chosen their parameter: the Pajarito Plateau. Geographically, the

  19. Shear wave anisotropy beneath the Tibetan Plateau

    Science.gov (United States)

    McNamara, Daniel E.; Owens, Thomas J.; Silver, Paul G.; Wu, Frances T.

    1994-07-01

    Eleven broadband digital seismic stations were deployed across the central Tibetan Plateau in the first extensive passive-source experiment attempted within the Tibetan Plateau. One year of recording resulted in 186 event-station pairs which we analyze to determine the characteristics of shear wave splitting in the upper mantle beneath the array. Measurements of the fast polarization direction (phi) and delay time (delta-t) for SKS and direct S arrivals reveal systematic variations along the north-south oriented array. In the north central region of the plateau, very large delay times are observed at three stations, the largest of which is BUDO with delta-t = 2.4 s. However, at TUNL, which is off the northern edge of the plateau and 110 km from BUDO, and at sites in the south central plateau, delta-t decreases by nearly a factor of 3. We also observe a systematic rotation of phi from about 45 deg (NE) to 90 deg (E-W) from south to north along the array. A previously identified zone of inefficient Sn propagation correlates well with our region of large delta-t observations. The large delay times suggest that a relatively high number of anisotropic crystals are preferentially alligned within the mantle-lid, beneath the north central portion of the Tibetan Plateau. In most cases, fast polarization directions appear to be parallel to surface geologic features suggesting as much as 200 km of the upper mantle has been involved in the collisional deformation that has produced the Tibetan Plateau.

  20. [Soil anti-erodibility of abandoned lands during different succession stages of plant community in hilly-gullied region of the Loess Plateau: Take Fangta small watershed as an example].

    Science.gov (United States)

    Yan, Fang-chen; Jiao, Ju-ying; Cao, Bin-ting; Yu, Wei-jie; Wei, Yan-hong; Kou, Meng; Hu, Shu

    2016-01-01

    Field survey and laboratory experiment were conducted to study the soil anti-erodibility of abandoned croplands during different vegetation succession stages in hilly-gullied region of the Loess Plateau, based on the analysis of soil particle composition, size distribution and group characteristics, soil aggregate fractal dimensions and stability. The results showed that in the earlier stages of succession from annual to perennial herbs in abandoned croplands, soil size distribution changed a little bit, the fractal dimension of soil particle increased, soil structure improved, fractal dimension and damage percent of soil aggregate structure decreased, soil stability increased, thus soil anti-erodibility increased. Therefore, natural restoration of vegetation is of great significance to improve the soil structure, increase soil erosion resistance, reduce soil erosion and promote sustainable development of regional ecological environment.

  1. Mineralization and other geologic factors related to the Morrison Formation in particular the northern two-thirds of the Colorado Plateau region; basic data and factor-analysis results

    Science.gov (United States)

    Cadigan, Robert Allen

    1982-01-01

    A vanadium-mercury mineralization factor and five other significant geologic factors were determined by multivariate factor analysis of data for Morrison Formation rock samples from the Colorado Plateau region. The data presented in the report were obtained from an agglomeration of 876 samples which yielded a correlation matrix of 44 variables. The variables consisted of geochemical, petrographic, and geographic location parameters. Mineralization factor scores demonstrate the relative intensity of mineralization in rock samples collected in and around uranium-vanadium ore deposits. The factors affecting composition and texture of the rocks identified from the analysis are: (1) metalliferous mudstones; (2) interstitial carbonate cements; (3) competing sources of different composition; (4) heavy mineral sources; (5) vanadium mineralization; and (6) regional and stratigraphic sampling bias.

  2. Radiative plateau inflation

    CERN Document Server

    Ballesteros, Guillermo

    2016-01-01

    We describe how monomial chaotic inflation becomes compatible with the latest CMB data thanks to radiative corrections producing a plateau. The interactions of the inflation with other fields, required for reheating, can flatten the potential and moderate the production of primordial gravitational waves, keeping these below the current upper bound. We show that the appearance of a plateau requires that the inflaton couples to fermions and to another scalar or a gauge group. We give concrete examples of minimal particle physics models leading to plateaus for quadratic and quartic chaotic inflation. We also provide a three-parameter model-independent description of radiatively corrected inflation that is amenable to CMB analyses.

  3. Plateau's Problem: What's Next

    OpenAIRE

    Harrison, Jenny; Pugh, Harrison

    2015-01-01

    Plateau's problem is not a single conjecture or theorem, but rather an abstract framework, encompassing a number of different problems in several related areas of mathematics. In its most general form, Plateau's problem is to find an element of a given collection \\(\\cal{C} \\) of "surfaces" specified by some boundary constraint, which minimizes, or is a critical point of, a given "area" function \\(F:\\cal{C}\\to \\R \\). In addition, one should also show that any such element satisfies some sort o...

  4. Modifications to the modular three-dimensional finite-difference ground-water flow model used for the Columbia Plateau Regional Aquifer-System Analysis, Washington, Oregon, and Idaho

    Science.gov (United States)

    Hansen, A.J.

    1993-01-01

    The report documents modifications to the U.S. Geological Survey's modular three-dimensional finite-difference ground-water flow model used for a regional aquifer-system analysis of the Columbia Plateau. The report, which describes the concepts and mathematical basis for the modifications, is intended for potential users who are familiar with the original modular model. The modifications permit flow from a layer to any adjacent layer, allow the model to retain a cell of a layer that has been cut completely through by a canyon, and allow placing ground-water flow barriers on only specified branch conductances; a special version of the modified model uses a convergent grid. The report describes the data-input items that this modified model must read.

  5. Monitoring coal mine changes and their impact on landscape patterns in an alpine region: a case study of the Muli coal mine in the Qinghai-Tibet Plateau.

    Science.gov (United States)

    Qian, Dawen; Yan, Changzhen; Xing, Zanpin; Xiu, Lina

    2017-10-14

    The Muli coal mine is the largest open-cast coal mine in the Qinghai-Tibet Plateau, and it consists of two independent mining sites named Juhugeng and Jiangcang. It has received much attention due to the ecological problems caused by rapid expansion in recent years. The objective of this paper was to monitor the mining area and its surrounding land cover over the period 1976-2016 utilizing Landsat images, and the network structure of land cover changes was determined to visualize the relationships and pattern of the mining-induced land cover changes. In addition, the responses of the surrounding landscape pattern were analysed by constructing gradient transects. The results show that the mining area was increasing in size, especially after 2000 (increased by 71.68 km 2 ), and this caused shrinkage of the surrounding lands, including alpine meadow wetland (53.44 km 2 ), alpine meadow (6.28 km 2 ) and water (6.24 km 2 ). The network structure of the mining area revealed the changes in lands surrounding the mining area. The impact of mining development on landscape patterns was mainly distributed within a range of 1-6 km. Alpine meadow wetland was most affected in Juhugeng, while alpine meadow was most affected in Jiangcang. The results of this study provide a reference for the ecological assessment and restoration of the Muli coal mine land.

  6. Plateau Indian Ways with Words

    Science.gov (United States)

    Monroe, Barbara

    2009-01-01

    The indigenous rhetoric of the Plateau Indians continues to exert a discursive influence on student writing in reservation schools today. Plateau students score low on state-mandated tests and on college writing assignments, in large part because the pervasive personalization of Plateau rhetoric runs counter to the depersonalization of academic…

  7. Phylogeographic evidence for a link of species divergence of Ephedra in the Qinghai-Tibetan Plateau and adjacent regions to the Miocene Asian aridification.

    Directory of Open Access Journals (Sweden)

    Ai-Li Qin

    Full Text Available The Qinghai-Tibetan Plateau (QTP has become one of the hotspots for phylogeographical studies due to its high species diversity. However, most previous studies have focused on the effects of the Quaternary glaciations on phylogeographical structures and the locations of glacial refugia, and little is known about the effects of the aridization of interior Asia on plant population structure and speciation. Here the chloroplast DNA (cpDNA trnT-trnF and trnS-trnfM sequences were used to investigate the differentiation and phylogeographical history of 14 Ephedra species from the QTP and northern China, based on a sampling of 107 populations. The phylogeographical analysis, together with phylogenetic reconstruction based on combined four cpDNA fragments (rbcL, rpl16, rps4, and trnS-trnfM, supports three main lineages (eastern QTP, southern QTP, and northern China of these Ephedra species. Divergence of each lineage could be dated to the Middle or Late Miocene, and was very likely linked to the uplift of the QTP and the Asian aridification, given the high drought and/or cold tolerance of Ephedra. Most of the Ephedra species had low intraspecific variation and lacked a strong phylogeographical structure, which could be partially attributed to clonal reproduction and a relatively recent origin. In addition, ten of the detected 25 cpDNA haplotypes are shared among species, suggesting that a wide sampling of species is helpful to investigate the origin of observed haplotypes and make reliable phylogeographical inference. Moreover, the systematic positions of some Ephedra species are discussed.

  8. Transmission dynamics of Fasciola hepatica in the Plateau Region of Mexico. Effect of weather and treatment of mammals under current farm management.

    Science.gov (United States)

    Cruz-Mendoza, Irene; Quiroz-Romero, Héctor; Correa, Dolores; Gómez-Espinoza, Guillermo

    2011-01-10

    The aim of the present work was to study the dynamics of Fasciola hepatica natural infection in ovines, caprines, bovines and two mollusc species, Lymnaea (Fossaria) humilis and Lymnaea (F.) bulimoides, from 2004 to mid 2007 under normal farm management conditions, and the relation to climate changes. The study was performed in a research centre in the plateau of Mexico. Temperature and rainfall were registered every month, as well as the number and intensity of infection in livestock and molluscs, as determined by coprology and direct observation/cercariae release, respectively. The first two years mammals were treated with clorsulon/ivermectin because the animals were harbouring concomitant intestinal nematode infections and this was the available drug combination. During the second period treatment was with triclabendazole. The temperature ranged from around cero to 30 °C, except during September 2005 to January 2006, when a cold climate prevailed. The rainfall augmented every year in July-August, and slightly in April, 2006. Lymneid snails appeared during or immediately after the rainfall peaks of 2004 and 2006, while few L. humilis and no L. bulimoides were present during the same period of 2005, probably because it was cold. A total of 15564 cercariae were released from molluscs during the wet time of 2004, 76 during 2005 and 368 in 2006. Several peaks of infection in mammals were observed, most occurring up to 4 months after the snails had disappeared. As expected, the weather had strong impact on snails and then on livestock infection. Also, treatment given to livestock was related to reduced cercarieae release five months later. Therefore, the combination of treatment and inspection of snails in the biotopes where the livestock graze may facilitate control of fasciolosis under current farm management. Copyright © 2010 Elsevier B.V. All rights reserved.

  9. Vegetation Changes in the Permafrost Regions of the Qinghai-Tibetan Plateau from 1982-2012: Different Responses Related to Geographical Locations and Vegetation Types in High-Altitude Areas

    Science.gov (United States)

    Wu, Xiaodong; Zhao, Lin; Yue, Guangyang; Nan, Zhuotong; Wang, Puchang; Yi, Shuhua; Zou, Defu; Qin, Yu; Wu, Tonghua; Shi, Jianzong

    2017-01-01

    The Qinghai-Tibetan Plateau (QTP) contains the largest permafrost area in a high-altitude region in the world, and the unique hydrothermal environments of the active layers in this region have an important impact on vegetation growth. Geographical locations present different climatic conditions, and in combination with the permafrost environments, these conditions comprehensively affect the local vegetation activity. Therefore, the responses of vegetation to climate change in the permafrost region of the QTP may be varied differently by geographical location and vegetation condition. In this study, using the latest Global Inventory Modeling and Mapping Studies (GIMMS) Normalized Difference Vegetation Index (NDVI) product based on turning points (TPs), which were calculated using a piecewise linear model, 9 areas within the permafrost region of the QTP were selected to investigate the effect of geographical location and vegetation type on vegetation growth from 1982 to 2012. The following 4 vegetation types were observed in the 9 selected study areas: alpine swamp meadow, alpine meadow, alpine steppe and alpine desert. The research results show that, in these study areas, TPs mainly appeared in 2000 and 2001, and almost 55.1% and 35.0% of the TPs were located in 2000 and 2001. The global standardized precipitation evapotranspiration index (SPEI) and 7 meteorological variables were selected to analyze their correlations with NDVI. We found that the main correlative variables to vegetation productivity in study areas from 1982 to 2012 were precipitation, surface downward long-wave radiation and temperature. Furthermore, NDVI changes exhibited by different vegetation types within the same study area followed similar trends. The results show that regional effects rather than vegetation type had a larger impact on changes in vegetation growth in the permafrost regions of the QTP, indicating that climatic factors had a larger impact in the permafrost regions than the

  10. Vegetation Changes in the Permafrost Regions of the Qinghai-Tibetan Plateau from 1982-2012: Different Responses Related to Geographical Locations and Vegetation Types in High-Altitude Areas.

    Directory of Open Access Journals (Sweden)

    Zhiwei Wang

    Full Text Available The Qinghai-Tibetan Plateau (QTP contains the largest permafrost area in a high-altitude region in the world, and the unique hydrothermal environments of the active layers in this region have an important impact on vegetation growth. Geographical locations present different climatic conditions, and in combination with the permafrost environments, these conditions comprehensively affect the local vegetation activity. Therefore, the responses of vegetation to climate change in the permafrost region of the QTP may be varied differently by geographical location and vegetation condition. In this study, using the latest Global Inventory Modeling and Mapping Studies (GIMMS Normalized Difference Vegetation Index (NDVI product based on turning points (TPs, which were calculated using a piecewise linear model, 9 areas within the permafrost region of the QTP were selected to investigate the effect of geographical location and vegetation type on vegetation growth from 1982 to 2012. The following 4 vegetation types were observed in the 9 selected study areas: alpine swamp meadow, alpine meadow, alpine steppe and alpine desert. The research results show that, in these study areas, TPs mainly appeared in 2000 and 2001, and almost 55.1% and 35.0% of the TPs were located in 2000 and 2001. The global standardized precipitation evapotranspiration index (SPEI and 7 meteorological variables were selected to analyze their correlations with NDVI. We found that the main correlative variables to vegetation productivity in study areas from 1982 to 2012 were precipitation, surface downward long-wave radiation and temperature. Furthermore, NDVI changes exhibited by different vegetation types within the same study area followed similar trends. The results show that regional effects rather than vegetation type had a larger impact on changes in vegetation growth in the permafrost regions of the QTP, indicating that climatic factors had a larger impact in the permafrost

  11. Influences of the climate changes and pollutants over the Asian Monsoon/Tibetan Plateau region on transport of ice, aerosols and water vapor to the upper troposphere and lower stratosphere (Invited)

    Science.gov (United States)

    Fu, R.; Zhang, K.; Chakraborty, S.

    2013-12-01

    The Asian monsoon and Tibetan Plateau (TP) region plays a key role in determining the summer atmospheric diabatic heating and circulation of the northern hemisphere and global troposphere-to-stratosphere transport. This region has experienced significant changes of surface temperature, convection and winds. To explore how these climatic changes, combining with high level of pollutions from industrial and biomass burning emissions, and dust from the upwind direction, would influence transport of ice and aerosols to the upper troposphere and lower stratosphere (UT/LS) of that region, and water vapor to the global stratosphere, we have carried out the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model (WACCM) simulations and analyzed several reanalysis products and a suite of satellite datasets. The results suggest that the surface warming and increase of convection over the TP appear to dominate the water vapor variability over the UT/LS in boreal summer, whereas tropical sea surface temperature anomalies, especially that related to the El Niño-Southern Oscillation (ENSO) dominate the UL/LS water vapor variability in winter. In addition, anomalous warmer surface temperature over the TP in winter induces anomalous planetary wave activity over Pacific, which in turn, influences the three-dimensional Brewer-Dobson circulation, and UT/LS water vapor in both tropics and polar region. Our analysis of combined A-train satellites and the International Satellite Cloud Climatology Project Convective tracking data suggests that an increase of aerosol optical depth appears to increase the cloud ice-liquid water ratio, increase ice water content of the anvil clouds, which in turn, may increase the transport of aerosols to the UT/LS of the Asian monsoon/TP region. These effects can work in concert with surface warming of the TP and amplify their influence on the global troposphere-to-stratosphere water vapor transport during the boreal summer

  12. Mercury in forest mushrooms and topsoil from the Yunnan highlands and the subalpine region of the Minya Konka summit in the Eastern Tibetan Plateau.

    Science.gov (United States)

    Falandysz, Jerzy; Saba, Martyna; Liu, Hong-Gao; Li, Tao; Wang, Ji-Peng; Wiejak, Anna; Zhang, Ji; Wang, Yuan-Zhong; Zhang, Dan

    2016-12-01

    This study aimed to investigate and discuss the occurrence and accumulation of mercury in the fruiting bodies of wild-growing fungi (Macromycetes) collected from montane forests in two regions of southwestern China with differences in soil geochemistry, climate and geographical conditions. Fungal mycelia in soils of the subalpine region of the Minya Konka (Gongga Mountain) in Sichuan and in the highlands of Yunnan efficiently accumulated mercury in fruiting bodies (mushrooms). The examined sites in Yunnan with highly mineralized red and yellow soils showed Hg contents ranging from 0.066 to 0.28 mg kg -1 dry biomass (db) which is roughly similar to the results obtained for samples collected from sites with dark soils relatively rich in organic matter from a remote, the subalpine region of Minya Konka. Due to the remoteness of the subalpine section of Minya Konka, as well as its elevation and climate, airborne mercury from long-range transport could be deposited preferentially on the topsoil and the Hg levels determined in soil samples taken beneath the fruiting bodies were up to 0.48 mg kg -1 dry matter. In Yunnan, with polymetallic soils (Circum-Pacific Mercuriferous Belt), Amanita mushrooms showed mercury in caps of fruiting bodies of up to 7.3 mg kg -1 dry biomass. Geogenic Hg from the mercuriferous belt seems to be the overriding source of mercury accumulated in mushrooms foraged in the regions of Yunnan, while long-range atmospheric transport and subsequent deposition are the mercury sources for specimens foraged in the region of Minya Konka.

  13. The status of Chinkara Gazella bennettii (Mammalia: Cetartiodactyla: Bovidae at Mayureshwar Wildlife Sanctuary, Supe, Baramati, Pune and a note on its current distribution in the southwestern region of the Deccan Plateau of Maharashtra, India

    Directory of Open Access Journals (Sweden)

    Mahesh Chandrakant Gaikwad

    2016-03-01

    Full Text Available We conducted monthly road surveys for encounter rates of Chinkara Gazella bennettii in Mayureshwar Wildlife Sanctuary (MWS, Supe Baramati, Pune from June 2011 to May 2012.  The sighting records of Chinkara were collected from opportunistic surveys conducted in adjoining areas of the Sanctuary, up to a distance of 200km in the southwestern region of the Deccan plateau, Maharashtra. We observed that the Chinkara was facing threats from habitat depletion, including in MWS which was declared a sanctuary for their protection.  Road widening projects such as the four lane Pune-Solapur National Highway runs 13km on its northern side and a district highway from Ahmednagar to Satara running north-south from the boundary of the Sanctuary have been proposed.  Other threats like vehicular movement from tar roads crossing the sanctuary, a proposed underground canal, a major irrigation canal to be constructed along the boundary of the sanctuary, and the increasing number of fenced plots for new residential and other development projects are responsible for the reduction in suitable habitats of the Chinakara.  It appears that within a few years, the sanctuary will become an isolated patch of protected grassland, affecting the smooth movement of Chinkara within and beyond the sanctuary limits.  Therefore, the remaining population of Chinkara from the entire human dominated landscape will struggle for survival. 

  14. Determining geometric links between glaciers and lakes on the Tibetan plateau

    NARCIS (Netherlands)

    Phan Hien, V.; Lindenbergh, R.C.; Menenti, M.

    2013-01-01

    The Tibetan plateau and surrounding mountain ranges contain the largest amount of ice outside the polar region. The Tibetan plateau also contains more than one thousand lakes and is the origin of a large part of the water resources of South and East Asia, the most densely populated regions on earth.

  15. Last glacial tephra layers in the Talos Dome ice core (peripheral East Antarctic Plateau), with implications for chronostratigraphic correlations and regional volcanic history

    Science.gov (United States)

    Narcisi, Biancamaria; Petit, Jean Robert; Langone, Antonio

    2017-06-01

    Tephra isochrons offer considerable potential for correlating diverse palaeoarchives and highlighting regional climatic differences. They are especially useful when applied to polar ice records encompassing the last glacial, as these clearly portray the pronounced millennial-scale climate variability that characterised this period. Here we present the continuous record of primary fallout tephra layers in the East Antarctic Talos Dome ice core (72°49‧S, 159°11‧E), developed upon examination of the core sections spanning the glacial period 16.5 to 71 ka. A total of ca. 45 discrete tephra deposits precisely positioned stratigraphically relative to the temperature record for the core and dated using the AICC2012 timescale, were identified. Quantitative grain size, particle morphology, major and trace element composition using Coulter Counter, SEM, EPMA-WDS, and LA-ICP-MS analytical methods were studied as diagnostic features for tephra characterisation. The tephrostratigraphic framework provides a reference for future precise comparison between ice and sediment sequences across the Antarctic continent. Indeed, several potential markers characterised by distinct volcanic glass geochemistry and/or particular stratigraphic location (e.g., a 17.6-ka ash layer deposited during the well-known major acidity event) are now available for the direct linkage of palaeoclimatic archives. The Talos Dome tephra sequence, dominated by mid-distal pyroclastic products from the nearby Northern Victoria Land volcanoes, also represents the most comprehensive and best time-constrained record of regional Antarctic volcanism yet developed. It documents nearly continuous sustained explosive activity during the considered time interval and, combined with previous ice-core tephra results for the last and the current interglacial periods, suggests progressive compositional shift through time.

  16. Hydro-thermal processes and thermal offsets of peat soils in the active layer in an alpine permafrost region, NE Qinghai-Tibet plateau

    Science.gov (United States)

    Wang, Qingfeng; Jin, Huijun; Zhang, Tingjun; Cao, Bin; Peng, Xiaoqing; Wang, Kang; Xiao, Xiongxin; Guo, Hong; Mu, Cuicui; Li, Lili

    2017-09-01

    the Eboling Mountains. Moreover, the thermophysical properties of peat soils and high moisture contents in the active layer on peatlands resulted in the lower soil temperatures in the active layer close to the LLP on the northern slope of the Eboling Mountains than those found at the LLP at the western branch of the UHRB in the warm season, especially at the deeper depths (20-77 cm). They also resulted in the smaller freezing index (FI) and thawing index (TI) and larger FI/TI ratios of soils at the depths of 5 to 77 cm in the active layer near the LLP on the northern slope of the Eboling Mountains. In short, peatlands have unique thermophysical properties for reducing heat absorption in the warm season and for limiting heat release in the cold season as well. However, the permafrost zone has shrunk by 10-20 km along the major highways at the western branch of the UHRB since 1985, and a medium-scale retrogressive slump has occurred on the peatlands on the northern slope of the Eboling Mountains in recent decades. The results can provide basic data for further studies of the hydrological functions of different landscapes in alpine permafrost regions. Such studies can also enable evaluations and forecasts the hydrological impacts of changing frozen ground in the UHRB and of other alpine mountain regions in West China.

  17. Secondary succession and its effects on soil moisture and nutrition in abandoned old-fields of hilly region of Loess Plateau, China.

    Science.gov (United States)

    Du, Feng; Shao, Hong-Bo; Shan, Lun; Liang, Zong-Suo; Shao, Ming-An

    2007-08-01

    Floristic composition, community structure and soil moisture and nutrient contents in abandoned fields of different ages were analyzed to clarify the regenerative aspects of succession as a tool for vegetation restoration. The results indicated that secondary succession in this region can be interpreted as an auto-succession: there are main changes in species-relative abundance and species turnover. Annual or biennial species (e.g. Artemisia scoparia), acted as pioneers and strongly dominated the early stages. Then, they underwent a progressive decline, while forbs (e.g. Artemisia sacrorum) and grasses (e.g. Xanthium sibiricum) had their peak abundance at intermediate stages. Dwarf shrubs (e.g. Lespedeza dahurica) and short rhizome grass (e.g. Bothriochloa ischaemum) appeared at mid-succession stage and gradually increased in abundance during succession, becoming dominant at late stages. The first axis of detrended correspondence canonical analysis arranged the sites according to their fallow time, indicating a successional sere. The second axis, associated with diverging pathways of regeneration, correlated with topographic factors and soil moisture and nutrition. Structural divergence between plots increased as succession went on, attained the highest at the mid-succession stage, decreased at the late stage. Soil moisture and available phosphorus content decreased steadily with field age after their abandonment, whereas pools of organic matter, total and available nitrogen, potassium and total phosphorus increased with field age. The pace and direction of recovery of native vegetation and natural soil properties in these abandoned fields resembled classic old-field succession, which is a form of secondary succession that often serves as a template for guiding restoration efforts. Interface between the abandoned field soil and plant system was crucial to the above process. Our current study supported the generally accepted hypothesis in the succession literature.

  18. A plateau-valley separation method for multifunctional surfaces characterization

    DEFF Research Database (Denmark)

    Godi, Alessandro; Kühle, A.; De Chiffre, Leonardo

    2012-01-01

    method based on the separation between the plateau and valley regions has been developed. After properly determining a threshold between plateaus and valleys, the two regions are divided in two distinct profiles, which can be studied separately according to the specific function....

  19. CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY

    Energy Technology Data Exchange (ETDEWEB)

    BERGMAN, T. B.; STEFANSKI, L. D.; SEELEY, P. N.; ZINSLI, L. C.; CUSACK, L. J.

    2012-09-19

    THE CENTRAL PLATEAU REMEDIATION OPTIMIZATION STUDY WAS CONDUCTED TO DEVELOP AN OPTIMAL SEQUENCE OF REMEDIATION ACTIVITIES IMPLEMENTING THE CERCLA DECISION ON THE CENTRAL PLATEAU. THE STUDY DEFINES A SEQUENCE OF ACTIVITIES THAT RESULT IN AN EFFECTIVE USE OF RESOURCES FROM A STRATEGIC PERSPECTIVE WHEN CONSIDERING EQUIPMENT PROCUREMENT AND STAGING, WORKFORCE MOBILIZATION/DEMOBILIZATION, WORKFORCE LEVELING, WORKFORCE SKILL-MIX, AND OTHER REMEDIATION/DISPOSITION PROJECT EXECUTION PARAMETERS.

  20. Structural and Geologic Mapping of Southern Tellus Regio, Venus: Implications for Crustal Plateau Formation

    Science.gov (United States)

    Graupner, Melanie

    2013-03-01

    Crustal plateau formation on Venus is subject to animated debate, centered on plateau support and resulting surface deformation. Detailed mapping provides critical clues for plateau evolution. Southern Tellus Regio records broadly synchronous formation of contractional and extensional structures, accompanied by deposition of flood material. Short-wavelength folds occur across the entire plateau, the extent of which has previously been undocumented. Generally the early-formed structures record a high structural fluidity, marked by variable orientation of structures or juxtaposition of neighboring structural suites. This interpretation of the geologic history of the region indicates the necessity of an extremely high geothermal gradient and provides a means to evaluate the different crustal plateau hypotheses. The mantle downwelling, mantle upwelling, and pulsating continents hypotheses fail to accommodate the surface features recorded in this study. However, the lava pond hypothesis provides a suitable hypothesis of crustal plateau formation that accommodates structural elements recorded in this study.

  1. Environmental significance of mineral weathering and pedogenesis of loess on the southernmost Loess Plateau, China

    NARCIS (Netherlands)

    Huang, C.; Zhao, W.; Liu, F.; Tan, W.F.; Koopal, L.K.

    2011-01-01

    Soils derived from the Loess Plateau of China are regionally important and expression of the soil properties along the soil profile may be directly related to climate changes. The objective of this research was to analyze the clay mineral transformation of loess from the southernmost Loess Plateau,

  2. Seismic wave speed structure of the Ontong Java Plateau

    Science.gov (United States)

    Covellone, Brian M.; Savage, Brian; Shen, Yang

    2015-06-01

    The Ontong Java Plateau (OJP) represents the result of a significant event in the Earth's geologic history. Limited geophysical and geochemical data, as well as the plateau's relative isolation in the Pacific ocean, have made interpretation of the modern day geologic structure and its 120 Ma formation history difficult. Here we present the highest resolution image to date of the wave speed structure of the OJP region. We use a data set that combines Rayleigh waves extracted from both ambient noise and earthquake waveforms and an iterative finite-frequency tomography methodology. The combination of datasets allow us to best exploit the limited station distribution in the Pacific and image wave speed structures between 35 km and 300 km into the Earth. We image a region of fast shear wave speeds, greater than 4.75 km/s, that extends to greater than 100 km beneath the plateau. The wave speeds are similar to as observed in cratonic environments and are consistent with a compositional anomaly that resulted from the residuum of eclogite entrainment during the plateau's formation. The combination of our imaged wave speed structure and previous geochemical work suggest that a surfacing plume head entrained eclogite from the deep mantle and accounts for the anomalous buoyancy characteristics of the plateau and observed fast wave speeds.

  3. Gravitational salt tectonics above a rising basement plateau offshore Algeria

    Science.gov (United States)

    Gaullier, Virginie; Vendeville, Bruno C.; Besème, Grégoire; Legoux, Gaetan; Déverchère, Jacques; Lymer, Gaël

    2017-04-01

    Seismic data (survey "MARADJA 1", 2003) offshore the Algerian coast have imaged an unexpected deformation pattern of the Messinian salt (Mobile Unit; MU) and its sedimentary overburden (Messinian Upper Unit and Plio-Quaternary) above an actively rising plateau in the subsalt basement. From a geodynamic point of view, the region is undergoing crustal convergence, as attested by the Boumerdes earthquake (2003, magnitude 6.8). The rise of this plateau, forming a 3D promontory restricted to the area offshore Algiers, is associated with that geodynamic setting. The seismic profiles show several subsalt thrusts (Domzig et al. 2006). The data provided additional information on the deformation of the Messinian mobile evaporitic unit and its Plio-Quaternary overburden. Margin-perpendicular profiles show mostly compressional features (anticlines and synclines) that had little activity during Messinian times, then grew more during Plio-Quaternary times. A few normal faults are also present, but are not accompanied by salt rise. By contrast, margin-parallel profiles clearly show that extensional, reactive salt diapiric ridges (symptomatic with their triangular shape in cross section) formed early, as early as the time of deposition of the Messinian Upper Unit, as recorded by fan-shaped strata. These ridges have recorded E-W, thin-skinned gravity gliding above the Messinian salt, as a response to the rise of the basement plateau. We tested this hypothesis using two analogue models, one where we assumed that the rise of the plateau started after Messinian times (initially tabular salt across the entire region), the second model assumed that the plateau had already risen partially as the Messininan Mobile Unit was deposited (salt initially thinner above the plateau than in the adjacent regions). In both experiments, the rise of the plateau generated preferential E-W extension above the salt, combined with N-S shortening. Extension was caused by gravity gliding of the salt from

  4. The impacts of the summer plateau monsoon over the Tibetan Plateau on the rainfall in the Tarim Basin, China

    Science.gov (United States)

    Zhao, Yong; Huang, Anning; Zhou, Yang; Yang, Qing

    2016-10-01

    The impacts of the summer plateau monsoon (PM) over the Tibetan Plateau on summer rainfall over the Tarim Basin in northwest China are investigated, based on the observed rainfall data at 34 stations and the NCEP/NCAR reanalysis data during 1961 to 2007. Results showed that the PM is well correlated to the summer rainfall over the Tarim Basin. Process analysis shows that strong PM corresponds to an anomalous cyclone over the Tibetan Plateau in the middle troposphere and an anomalous anticyclone in the upper troposphere over northwest part of Tibetan Plateau. They result in cold air moving from high latitudes into Central Asia over the western part of Tibetan Plateau. The concurrences of the cooling in the middle-upper troposphere over Central Asia leads to an anomalous cyclone over Central Asia at 500 hPa and the anomalous descending motions prevailing over the cooling region. Associated with this anomaly, there are enhanced southerly winds and corresponding ascending motion over the Tarim Basin located in the east of the cooling region. These processes lead to more summer rainfall over the Tarim Basin.

  5. Prevalence of snakebites in Taraba and Plateau States of Nigeria ...

    African Journals Online (AJOL)

    This study was undertaken to outline the epidemiological profile of snakebites in the middle belt region of Nigeria, using Plateau and Taraba States as a case study. Records of 917 cases of snakebites from eight secondary health facilities, spread across the two states were collected retrospectively, covering January 1999 ...

  6. Nitrogen loss from windblown agricultural soils in the Columbia Plateau

    Science.gov (United States)

    Wind erosion of agricultural soils can degrade both air quality and soil productivity in the Columbia Plateau of the Pacific Northwest United States. Soils in the region contain fine particles that, when suspended, are highly susceptible to long range transport in the atmosphere. Nitrogen (N) associ...

  7. Discovery of cryptic Armillaria solidipes genotypes within the Colorado Plateau

    Science.gov (United States)

    J. W. Hanna; N. B. Klopfenstein; M. -S. Kim; S. M. Ashiglar; A. L. Ross-Davis; G. I. McDonald

    2012-01-01

    Armillaria solidipes (= A. ostoyae) is a root-disease pathogen that causes severe losses in growth and productivity of forest trees throughout the Northern Hemisphere. This species is genetically diverse with variable disease activities across different regions of the world. In North America, A. solidipes in the Colorado Plateau exists in drier habitats and causes more...

  8. Verçenik Plateau Alternative Tourism and Recreational Activities

    Directory of Open Access Journals (Sweden)

    İzzet İSLAMOĞLU

    2014-08-01

    Full Text Available In the last century working life become easier and result of this increased people free time, after that interest of tourism activities wide spread all over. Plateau tourism or highland places are not first choices of the tourism activities but plateau rec reation will give an application for potential activity place. Turkey have unmatched nature and rich environmental resources will able to give any kind of tourism activities. In that context city of Rize took place in Black Sea region with different capabi lities, one of the source areas that make up tourism and recreational activities. This research intended for Vercenik Plateau take place 60 km away from Camlihemsin district center and will determine potential tourism and recreational application. Research is based on field observation and studies. This information obtained as a result ofthis evaluationbeing associated toliterature data and that information determined which exercise can be done in the field. Vercenik Plateau; with pristine environment and ru ral locations, the fresh water supplies, unique flora for city of Rize has high recreational capacities.As a result of study; Vercenik Plateau has natural features with the great potential of the alternative tourism as it is suitable for areas but not asse ss enough potential tourism and recreational activities without prior review has been observed.

  9. Observational facts of sustained departure plateau vortexes

    Science.gov (United States)

    Yu, Shuhua; Gao, Wenliang; Peng, Jun; Xiao, Yuhua

    2014-02-01

    By using the twice-daily atmospheric observation data from 1998 to 2012, station rainfall data, Tropical Rainfall Measure Mission (TRMM) data, as well as the plateau vortex and shear line year book, characteristics of the sustained departure plateau vortexes (SDPVs) are analyzed. Some new useful observational facts and understanding are obtained about the SDPV activities. The following results are obtained. (1) The active period of SDPVs is from June to August, most in July, unlike that of the unsustained departure plateau vortexes (UDPVs), which have same occurrence frequencies in the three summer months. (2) The SDPVs, generated mainly in the Qumalai neighborhood and situated in a sheared surrounding, move eastward or northeastward, while the UDPVs are mainly led by the upper-level trough, and move eastward or southeastward. (3) The SDPVs influence wide areas of China, even far to the Korean Peninsula, Japan, and Vietnam. (4) The SDPVs change their intensities and properties on the way to the east. Most of them become stronger and produce downpour or sustained regional rainstorms to the south of Yellow River. (5) The longer the SDPV sustains, the more baroclinity it has. (6) When an SDPV moves into the sea, its central pressure descends and rainfall increases in all probability. (7) An SDPV might spin over the bend of the Yellow River when there exists a tropical cyclone in the East China Sea. It could also move oppositely to a landed tropical low pressure originated from the sea to the east of Taiwan or from the South China Sea.

  10. Reduced convergence within the Tibetan Plateau by 26 Ma?

    Science.gov (United States)

    Meng, Jun; Coe, Robert S.; Wang, Chengshan; Gilder, Stuart A.; Zhao, Xixi; Liu, Hao; Li, Yalin; Ma, Pengfei; Shi, Kai; Li, Shuai

    2017-07-01

    Understanding the dynamics of double-thickening and uplifting of the Tibetan crust requires constraints on the magnitude and timing of crustal shortening. New elongation/inclination (E/I)-corrected paleomagnetic data from 26-22 Ma sediments indicate that the latitude of southern Tibet in the early Miocene was 31.1/-6.8/+5.2°N, not significantly different from today. This implies that the southern margin of Asia, which was at 21-24°N latitude from the Late Cretaceous to the early Eocene, advanced 8-10° northward between the early Eocene and the latest Oligocene. Our results therefore suggest that at least 900-1100 km of continental shortening and significant regional uplift of the plateau occurred between the early Eocene and late Oligocene. Our results suggest that N-S intra-Asian convergence was considerably reduced around 26 Ma, corresponding to a transition from compression to extension within the Tibetan Plateau.type="synopsis">type="main">Plain Language SummaryTwo critical questions involving the geodynamic evolution of the Tibetan plateau are (i) when did a compression-dominated tectonic regime change to an extension-dominated tectonic regime on the plateau and (ii) how does this timing correlate with double thickening of the crust? Here we provide paleomagnetic evidence for the timing, magnitude, and partitioning of intra-Asian convergence. Our results imply a first-order constraint of 900-1100 km north-south shortening concentrated within the interval from 53 to 26 Ma. This suggests that a fundamental change at 26 Ma occurred in the geodynamics of the Tibetan Plateau marked by a reduction in large-scale convergence and compressive deformation. The implication is that significant regional uplift of the proto-Tibetan Plateau occurred within the 55-26 Ma interval. The paleolatitude, paleoclimate, and topography of south central Tibet seen at present were likely established around 26 Ma.

  11. Soil carbon sequestration potential for "Grain for Green" project in Loess Plateau, China.

    Science.gov (United States)

    Chang, Ruiying; Fu, Bojie; Liu, Guohua; Liu, Shuguang

    2011-12-01

    Conversion of cropland into perennial vegetation land can increase soil organic carbon (SOC) accumulation, which might be an important mitigation measure to sequester carbon dioxide from the atmosphere. The "Grain for Green" project, one of the most ambitious ecological programmes launched in modern China, aims at transforming the low-yield slope cropland into grassland and woodland. The Loess Plateau in China is the most important target of this project due to its serious soil erosion. The objectives of this study are to answer three questions: (1) what is the rate of the SOC accumulation for this "Grain for Green" project in Loess Plateau? (2) Is there a difference in SOC sequestration among different restoration types, including grassland, shrub and forest? (3) Is the effect of restoration types on SOC accumulation different among northern, middle and southern regions of the Loess Plateau? Based on analysis of the data collected from the literature conducted in the Loess Plateau, we found that SOC increased at a rate of 0.712 TgC/year in the top 20 cm soil layer for 60 years under this project across the entire Loess Plateau. This was a relatively reliable estimation based on current data, although there were some uncertainties. Compared to grassland, forest had a significantly greater effect on SOC accumulation in middle and southern Loess Plateau but had a weaker effect in the northern Loess Plateau. There were no differences found in SOC sequestration between shrub and grassland across the entire Loess Plateau. Grassland had a stronger effect on SOC sequestration in the northern Loess Plateau than in the middle and southern regions. In contrast, forest could increase more SOC in the middle and southern Loess Plateau than in the northern Loess Plateau, whereas shrub had a similar effect on SOC sequestration across the Loess Plateau. Our results suggest that the "Grain for Green" project can significantly increase the SOC storage in Loess Plateau, and it is

  12. Intercropping competition between apple trees and crops in agroforestry systems on the Loess Plateau of China

    National Research Council Canada - National Science Library

    Gao, Lubo; Xu, Huasen; Bi, Huaxing; Xi, Weimin; Bao, Biao; Wang, Xiaoyan; Bi, Chao; Chang, Yifang

    2013-01-01

    Agroforestry has been widely practiced in the Loess Plateau region of China because of its prominent effects in reducing soil and water losses, improving land-use efficiency and increasing economic returns...

  13. Soil nutrient assessment based on attribute recognition model in the Loess Plateau of China

    National Research Council Canada - National Science Library

    Jiao, Feng; Wen, Zhong-Ming; An, Shao-Shan

    2013-01-01

    ... under restoration for 5, 10, 15, 20, and 25. Attribute recognition model based on entropy weight was used to evaluate the soil fertility of typical region in the Loess Plateau of China, which contained 52 soil samples with 6 physical...

  14. Desempenho de cinco clones jovens de seringueira na região do Planalto Ocidental Paulista Performance of five young clones of rubber tree in the São Paulo Occidental plateau region

    Directory of Open Access Journals (Sweden)

    Juliane Ribeiro Cavalcante

    2002-12-01

    Full Text Available A Região do Planalto Ocidental Paulista tem se destacado como pólo produtor de borracha natural. Visando fornecer informações sobre a adaptação dos clones de seringueira [Hevea brasiliensis (Wildd. ex. Adr. de Juss Müell. Arg.] RRIM 600, GT 1, RRIM 701, IAN 873 e PB 235, em São José do Rio Preto (SP, realizaram-se avaliações de alguns caracteres de sua biologia, pelo acompanhamento das trocas gasosas e mensuração do desenvolvimento vegetativo durante os primeiros 18 meses após o enxerto sobre Tjir 16. A altura de RRIM 600 atingiu, em média, 3,74 m e o diâmetro do caule de IAN 873 e RRIM 600, 2,50 cm. PB 235 apresentou o menor índice relativo de crescimento durante o período. No período úmido, os valores das trocas gasosas não diferiram significativamente entre os clones, com valores médios da taxa fotossintética de 9,45 mmol.m-2.s-1; para a taxa de transpiração, 3,84 mmol.m-2.s-1, e para a condutância estomática, de 0,096 mol.m-2.s-1. Diferenças entre os valores de trocas gasosas ocorreram apenas no período seco, com redução mais acentuada para PB 235. Considerando o conjunto dos caracteres analisados, o desempenho dos clones IAN 873 e RRIM 600 foi superior, e do clone PB 235, inferior.The region of São Paulo Occidental Plateau is well known for its part as a major producer of natural rubber. In order to obtain information about adaptation of rubber tree clones [Hevea brasiliensis (Wildd. ex. Adr. de Juss Müell. Arg.] RRIM 600, RRIM 701, IAN 873, PB 235 and GT 1, in the city of São José do Rio Preto some biologic characteristics were evaluated. Analysis were performed by monitoring gas exchanges and by measuring vegetative development, during the 18 months after engraft on the Tjir 16 clonal rootstocks. The height of RRIM 600 reached a mean of 3,74 m, and the diameter of the stem of IAN 873 and RRIM 600 reached the mean of 2,50 cm. Clone PB 235 presented the lowest relative growth during the period. During the

  15. Sensitivity of LUCC on the Surface Temperature of Tibetan Plateau

    Science.gov (United States)

    Qi, W.; Deng, X.; Wu, F.

    2016-12-01

    The Tibetan Plateau has an important effect on the ecological security in China, even in Asia, which makes the region become the hot spot in recently research. Under the joint influence of global change and human activities, ecosystem destabilizing and the increasing pressure on resources and environment emerge on the Tibetan Plateau, but the potential spatial sensitivity of land use and land cover changes(LUCC) on surface temperature has not been quantitatively analyzed. This study analyzed the mainly types of LUCC, urbanization, grassland degradation, deforestation on Tibetan Plateau along with Representative Concentration Pathways (RCPs) of the Intergovernmental Panel on Climate Change (IPCC). The LUCC in recent decades was first quantitatively analyzed in this study to give the basic fact with a significant increase in temperatures, reduced precipitation and increased evaporation. This study focused on the future spatio-temporal heterogeneity of the temperature and precipitation. Finally, the influencing factors with LUCC on Tibetan Plateau were simulated with the Weather Research and Forecasting (WRF) model, and the sensitivity of different land use types was spatially analyzed with Singular Value Decomposition (SVD). The results indicate that the large-area alpine grassland plays a more important role in alleviating global warming than other vegetation types do. The changes of the landscape structure resulting from the urban expansion play a significant role in intensifying regional temperature increase. In addition, the effects of LUCC on monthly average temperature change would vary from month to month with obviously spatial heterogeneity.

  16. Excessive afforestation and soil drying on China's Loess Plateau

    Science.gov (United States)

    Zhang, Shulei; Yang, Dawen

    2017-04-01

    Afforestation and deforestation are human disturbances to vegetation, which have profound impacts on regional eco-hydrological processes, the water and carbon cycles, and consequently, ecosystem sustainability. Since 1999, large scale revegetation has been carried out across China's Loess Plateau following the "Grain-to-Green Program" implemented by the Chinese government. This revegetation, particularly with forest, has caused negative eco-hydrological consequences, including streamflow decline and soil drying. Here, we have used "ecosystem optimality theory" and satellite observations, to assess the water balance under the climate-defined optimal and actual vegetation cover during 1982-2010 and its responses to future climate change (2011-2050) over the Loess Plateau. Results show that the current vegetation cover (0.48 on average) has already exceeded the climate-defined optimal cover (0.43 on average) in the most recent decade, especially in the middle-to-east Loess Plateau, indicating that it is the widespread over-planting, which is primarily responsible for soil drying in the area. In addition, both the optimal vegetation cover and soil moisture tend to decrease under future climate scenarios. Our findings suggest that further revegetation on the Loess Plateau should be applied with caution. To maintain a sustainable eco-hydrological environment in the region, a revegetation threshold should be urgently set, to limit future planting.

  17. The Colorado Plateau IV: shaping conservation through science and management

    Science.gov (United States)

    Wakeling, Brian F.; Sisk, Thomas D.; van Riper, Charles

    2010-01-01

    Roughly centered on the Four Corners region of the southwestern United States, the Colorado Plateau covers some 130,000 square miles of sparsely vegetated plateaus, mesas, canyons, arches, and cliffs in Arizona, Utah, Colorado, and New Mexico. With elevations ranging from 3,000 to 14,000 feet, the natural systems found within the plateau are dramatically varied, from desert to alpine conditions. This book focuses on the integration of science and resource management issues in this unique and highly varied environment. Broken into three subsections, this volume addresses conservation biology, biophysical resources, and inventory and monitoring concerns. The chapters range in content, addressing conservation issues–past, present, and future–on the Colorado Plateau, measurement of human impacts on resources, grazing and wildland-urban interfaces, and tools and methods for monitoring habitats and species. An informative read for people interested in the conservation and natural history of the region, the book will also serve as a valuable reference for those people engaged in the management of cultural and biological resources of the Colorado Plateau, as well as scientists interested in methods and tools for land and resource management throughout the West.

  18. The role of lower-crustal hydration in the tectonic evolution of the Colorado Plateau

    Science.gov (United States)

    Porter, Ryan; Hoisch, Thomas; Holt, William E.

    2017-08-01

    Geologists have long debated the timing and mechanism for uplift of the Colorado Plateau with numerous hypotheses proposed to explain each. We use surface wave tomography to examine the lithospheric structure of the Colorado Plateau and surrounding regions and combine these data with thermodynamic modeling to better constrain lower crustal composition, water content, and density. Our results show that about 15% ( 290 m) of the modern plateau elevation can be supported isostatically by hydration of the lower crust, which reduces the overall density of the lithosphere. Hydration of the Colorado Plateau lithosphere likely occurred due to dewatering of the Farallon slab during flat-slab subduction. Subsequent warming and extension have likely further reduced the density of the crust along the plateau margins by as much as 110 kg/m3. This is likely a result of extension encroaching into the plateau and small-scale convection occurring within the mantle surrounding the plateau, and may help explain the high topography on the margins of the plateau.

  19. Early Cenozoic Multiple Thrust in the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Zhenhan Wu

    2013-01-01

    Full Text Available Recently completed regional geological mapping at a scale of 1 : 250,000 or larger across all of the Tibetan Plateau coupled with deep seismic surveys reveals for the first time a comprehensive depiction of the major early Cenozoic thrust systems resulting from the northward subduction of the Indian Continental Plate. These systems define a series of overlapping north-dipping thrust sheets that thickened the Tibetan crust and lead to the rise of the plateau. The few south-dipping thrusts present apparently developed within a sheet when the back moved faster than the toe. Many of the thrusts are shown to extend to the middle-lower crustal depths by seismic data. The regional thrust systems are the Main Central, Renbu-Zedong, Gangdese, Central Gangdese, North Gangdese, Bangoin-Nujiang, Qiangtang, Hohxil, and South Kunlun Thrusts. The minimal southward displacements of the South Kunlun, Hohxil, South Qiangtang, and Central Gangdese Thrusts are estimated to be 30 km, 25 km, 150 km and 50 km, respectively. Deep thrusting began in the Himalaya-Tibetan region soon after India-Eurasia continental collision and led to crustal thickening and subsequent uplift of the Tibetan Plateau during Late Eocene-Early Miocene when the systems were mainly active. The major thrust systems ceased moving in Early Miocene and many were soon covered by lacustrine strata. This activity succeeded in the late Cenozoic to crustal extension and strike-slip movement in the central Tibetan Plateau. The revelation of the full array of the early Cenozoic thrust systems provides a much more complete understanding of the tectonic framework of the Tibetan Plateau.

  20. A policy-driven large scale ecological restoration: quantifying ecosystem services changes in the Loess Plateau of China

    National Research Council Canada - National Science Library

    Lü, Yihe; Fu, Bojie; Feng, Xiaoming; Zeng, Yuan; Liu, Yu; Chang, Ruiying; Sun, Ge; Wu, Bingfang

    2012-01-01

    .... A case study was conducted at the regional level in the ecologically vulnerable region of the Loess Plateau, China, through the use of several methods including the Universal Soil Loss Equation (USLE...

  1. Crustal architecture beneath the Tibet-Ordos transition zone, NE Tibet, and the implications for plateau expansion

    Science.gov (United States)

    Guo, Xiaoyu; Gao, Rui; Wang, Haiyan; Li, Wenhui; Keller, G. R.; Xu, Xiao; Li, Hongqiang; Encarnacion, John

    2015-12-01

    Most previous studies of the Tibetan Plateau have focused on the processes of crustal thickening and subsequent outward growth. However, lithospheric structure across the tectonic boundaries of the plateau has not yet been fully imaged, and therefore, how geological structures evolved in association with the lateral expansion of the margins remains unclear. Here together with interpretation of regional aeromagnetic anomalies, we employ a recently acquired 165 km long deep seismic reflection image that crosses the northeastern flank of the Tibetan Plateau. The resulting crustal "architecture" suggests that crustal shortening is a primary driver for plateau uplift of northeastern Tibet and that the Xiaoguan Shan to the east of the Liupan Shan belt marks the easternmost edge of the strata that has been affected by the northeastward growth of the plateau. In addition, decoupled crustal deformation owing to differential structural integrity has been accommodated during the subsequent northeastward growth of the plateau.

  2. Mapping risk of plague in Qinghai-Tibetan Plateau, China.

    Science.gov (United States)

    Qian, Quan; Zhao, Jian; Fang, Liqun; Zhou, Hang; Zhang, Wenyi; Wei, Lan; Yang, Hong; Yin, Wenwu; Cao, Wuchun; Li, Qun

    2014-07-10

    Qinghai-Tibetan Plateau of China is known to be the plague endemic region where marmot (Marmota himalayana) is the primary host. Human plague cases are relatively low incidence but high mortality, which presents unique surveillance and public health challenges, because early detection through surveillance may not always be feasible and infrequent clinical cases may be misdiagnosed. Based on plague surveillance data and environmental variables, Maxent was applied to model the presence probability of plague host. 75% occurrence points were randomly selected for training model, and the rest 25% points were used for model test and validation. Maxent model performance was measured as test gain and test AUC. The optimal probability cut-off value was chosen by maximizing training sensitivity and specificity simultaneously. We used field surveillance data in an ecological niche modeling (ENM) framework to depict spatial distribution of natural foci of plague in Qinghai-Tibetan Plateau. Most human-inhabited areas at risk of exposure to enzootic plague are distributed in the east and south of the Plateau. Elevation, temperature of land surface and normalized difference vegetation index play a large part in determining the distribution of the enzootic plague. This study provided a more detailed view of spatial pattern of enzootic plague and human-inhabited areas at risk of plague. The maps could help public health authorities decide where to perform plague surveillance and take preventive measures in Qinghai-Tibetan Plateau.

  3. Finite plateau in spectral gap of polychromatic constrained random networks

    Science.gov (United States)

    Avetisov, V.; Gorsky, A.; Nechaev, S.; Valba, O.

    2017-12-01

    We consider critical behavior in the ensemble of polychromatic Erdős-Rényi networks and regular random graphs, where network vertices are painted in different colors. The links can be randomly removed and added to the network subject to the condition of the vertex degree conservation. In these constrained graphs we run the Metropolis procedure, which favors the connected unicolor triads of nodes. Changing the chemical potential, μ , of such triads, for some wide region of μ , we find the formation of a finite plateau in the number of intercolor links, which exactly matches the finite plateau in the network algebraic connectivity (the value of the first nonvanishing eigenvalue of the Laplacian matrix, λ2). We claim that at the plateau the spontaneously broken Z2 symmetry is restored by the mechanism of modes collectivization in clusters of different colors. The phenomena of a finite plateau formation holds also for polychromatic networks with M ≥2 colors. The behavior of polychromatic networks is analyzed via the spectral properties of their adjacency and Laplacian matrices.

  4. Systeemomschrijving “Plateau 2.0”

    OpenAIRE

    Hoofs, Anita

    2017-01-01

    En varkenshok met plateau is een hok waarin varkens vrij beschikken over twee verblijfsniveaus, één op de begane grond en één op het plateau. Varkens kunnen gemakkelijk het plateau op - en aflopen via een trap. Bij toepassing van een plateau, dat voldoet aan de systeemomschrijving, mag het beschikbare vloeroppervlak van het plateau als beschikbaar vloeroppervlak meegerekend worden.

  5. Soil Erosion Study on the Chinese Loess Plateau

    Science.gov (United States)

    Hu, Yaxian; Guo, Shengli; Kuhn, Nikolaus

    2017-04-01

    The Chinese Loess Plateau, because of its highly erodible loess soils and hilly topography, has been extensively studied by soil scientists and geomorphologists. As a research hotspot, there are five national-level field stations across the Loess Plateau, with hundreds of erosion plots set up with various sizes, lengths, slope angles and vegetation covers. In addition, huge indoor rain simulation facilities exist in in different institutes which can provide rainfall simulations under a wide range of controlled conditions. Consequently, national-level restoration projects have achieved tremendous improvements in curbing soil erosion and improving regional agro-ecosystem, mostly by afforestation and soil rehabilitation. However, when implementing the advanced techniques and models that have been widely applied in the rest of the world, there are often regional considerations, which demand new approaches to overcome. One example are the unintentional impacts of restoration efforts, such as the establishment of apple orchards. Over 20 years, they have caused an increase in soil erodibility and lowered local ground water levels. Neither before the introduction of this landscape rehabilitation technique, nor now, has the impact of intensive fruit production been systematically studied, despite lending itself to systematic experiments. The lack of research is attributed to the general idea that trees protect soils and improve environmental services. This presentation identifies several such specific regional environmental issues associated with soil erosion on the Loess Plateau and discusses strategies to avoid missing important research questions.

  6. Greenhouse gases emissions in rivers of the Tibetan Plateau.

    Science.gov (United States)

    Qu, Bin; Aho, Kelly Sue; Li, Chaoliu; Kang, Shichang; Sillanpää, Mika; Yan, Fangping; Raymond, Peter A

    2017-11-29

    Greenhouse gases (GHGs) emissions from streams are important to regional biogeochemical budgets. This study is one of the first to incorporate stream GHGs (CO 2 , CH 4 and N 2 O) concentrations and emissions in rivers of the Tibetan Plateau. With one-time sampling from 32 sites in rivers of the plateau, we found that most of the rivers were supersaturated with CO 2 , CH 4 and N 2 O during the study period. Medians of partial pressures of CO 2 (pCO 2 ), pCH 4 and pN 2 O were presented 864 μatm, 6.3 μatm, and 0.25 μatm respectively. Based on a scaling model of the flux of gas, the calculated fluxes of CO 2 , CH 4 and N 2 O (3,452 mg-C m 2 d -1 , 26.7 mg-C m 2 d -1 and 0.18 mg-N m 2 d -1 , respectively) in rivers of the Tibetan Plateau were found comparable with most other rivers in the world; and it was revealed that the evasion rates of CO 2 and CH 4 in tributaries of the rivers of the plateau were higher than those in the mainstream despite its high altitude. Furthermore, concentrations of GHGs in the studied rivers were related to dissolved carbon and nitrogen, indicating that riverine dissolved components could be used to scale GHGs envision in rivers of the Tibetan Plateau.

  7. Into Tibet: An Early Pliocene Dispersal of Fossil Zokor (Rodentia: Spalacidae) from Mongolian Plateau to the Hinterland of Tibetan Plateau.

    Science.gov (United States)

    Li, Qiang; Wang, Xiaoming

    2015-01-01

    This paper reports the fossil zokors (Myospalacinae) collected from the lower Pliocene (~4.4 Ma) of Zanda Basin, southwestern Tibet, which is the first record in the hinterland of Tibetan Plateau within the Himalayan Range. Materials include 29 isolated molars belonging to Prosiphneus eriksoni (Schlosser, 1924) by having characters including large size, highly fused roots, upper molars of orthomegodont type, m1 anterior cap small and centrally located, and first pair of m1 reentrants on opposing sides, high crowns, and high value of dentine tract parameters. Based on the cladistics analysis, all seven species of Prosiphneus and P. eriksoni of Zanda form a monophyletic clade. P. eriksoni from Zanda, on the other hand, is nearly the terminal taxon of this clade. The appearance of P. eriksoni in Zanda represents a significant dispersal in the early Pliocene from its center of origin in north China and Mongolian Plateau, possibly via the Hol Xil-Qiangtang hinterland in northern Tibet. The fast evolving zokors are highly adapted to open terrains at a time when regional climates had become increasingly drier in the desert zones north of Tibetan Plateau during the late Miocene to Pliocene. The occurrence of this zokor in Tibet thus suggests a rather open steppe environment. Based on fossils of large mammals, we have formulated an "out of Tibet" hypothesis that suggests earlier and more primitive large mammals from the Pliocene of Tibet giving rise to the Ice Age megafauna. However, fossil records for large mammals are still too poor to evaluate whether they have evolved from lineages endemic to the Tibetan Plateau or were immigrants from outside. The superior record of small mammals is in a better position to address this question. With relatively dense age intervals and numerous localities in much of northern Asia, fossil zokors provide the first example of an "into Tibet" scenario--earlier and more primitive taxa originated from outside of the Tibetan Plateau and the

  8. Prehistoric human settling on the Tibetan Plateau

    Science.gov (United States)

    Chen, Fahu; Zhang, Dongju; Dong, Guanghui

    2017-04-01

    When and where did human first settle down on the Tibetan Plateau is under hot debate among archaeologist, anthropologists, geneticist and paleo-geographers. Based on systematic archaeological, chronological and archaeo-botanical studies of 53 sites in Northeastern Tibetan Plateau, we propose that agriculture facilitated human permanent settlement on the Tibetan Plateau initially since 5200 years ago below 2500 masl and since 3600 years ago up to around 4000 masl, possibly assisted by domesticated animals (Chen et al. 2015). By studying hand- and footprints in Chusang, Meyer et al. (2016) argue that hunter-gatherers permanently occupied central Tibetan Plateau in early Holocene without the help of agriculture. However, we think the limited hand- and footprints evidence found in Chusang could indicate no more than prehistoric hunter-gatherers presence on the remote central Tibetan Plateau in the early Holocene. In addition, by reviewing all the published archaeological data, we propose that human migrated to the Tibetan Plateau from the last Deglacial period to late Holocene mainly from North China via Yellow River valley and its tributary valleys in the Northeastern Tibetan Plateau (NETP). This migration is constituted of four stages (Upper Paleolithic, Epi-Paleolithic, Neolithic and Bronze Age) when human adapted to the high altitude environment and climate change with different strategies and techniques. Particularly, the prevail of microlithic technology in North China provoked hunter-gatherers' first visit to the NETP in relatively ameliorated last Deglacial period, and the the quick development of millet farming and subsequent mixed barley-wheat farming and sheep herding facilitated farmers and herders permanently settled in Tibetan Plateau, even above 3000 masl, during mid- and late Holocene. References: Chen et al., 2015. Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 BP. Science, 347: 248-250. Meyer et al., 2016

  9. Livelihood Vulnerability Assessment Of Farmers and Nomads in Eastern Ecotone of Tibetan Plateau

    Science.gov (United States)

    Yan, J.; Zhang, Y.

    2011-12-01

    Livelihood vulnerability assessment provides a scientific basis for anti-poverty of people and regional sustainable development in vulnerable area. Although there are massive discussions on concept of vulnerability, it is still difficult to make it quantitative and to carry out comprehensive appraise. Vulnerability assessments based on sustainable livelihood frame are widely accepted in case studies for attentions to vulnerable groups. However, these case studies are always on regional scale and never reflect how climate change affects people's livelihood and adaptive capability of people. It is necessary to seek vulnerable assessment index system and means based on livelihood process of local people. This paper develops a livelihood vulnerability assessment index system on the basis of sustainable livelihood framework and appraises livelihood vulnerability values of 11 townships, using data of 879 sample households. Livelihood vulnerability assessment index system reflects main risks, livelihood assets and adaptation strategies of local people and government. The results show that livelihood vulnerability level of plateau region is higher than that of mountain to plateau region and mountain gorge region. Manzhang Township in plateau region is the most vulnerable township and nomads there cannot cope with risks of climate change, meadow degeneration and herbs degradation. Upper part of mountain to plateau region and the whole plateau region have high livelihood vulnerability values and local nomads would not cope with risks if no measures are taken by government. The driving forces of livelihood vulnerability include strikes of risks and deficiency of livelihood assets and adaptive capability. Farmers and nomads in high mountain gorge region and lower part of mountain to plateau region can cope with these risks, meanwhile, there are more employment opportunities in second and tertiary industries are needed to help them realize livelihood diversification. Therefore

  10. Dendroclimatic reconstructions for the southern Colorado plateau

    Energy Technology Data Exchange (ETDEWEB)

    Dean, J.S.; Funkhouser, G.S. [Univ. of Arizona, Tucson, AZ (United States)

    1995-09-01

    A geographical network of climate sensitive tree-ring chronologies consisting of 25 archaeological sequences and two bristlecone pine series provides the basis for high resolution reconstructions of low and high frequency climatic variability on the southern Colorado Plateau over the last 1,500 years. Qualitative and quantitative dendroclimatic analyses of these data produce annual retrodictions of yearly and seasonal precipitation and summer Palmer Drought Severity Indices for each station and reconstructions of regional scale patterns in climatic variability. These reconstructions provide detailed information on climatic fluctuations that affected biotic and human populations as well as long-term baseline data for evaluating present-day climate and estimating future climatic trends. When integrated with other measures of past environmental variability, these reconstructions specify periods of favorable and unfavorable environmental conditions that would have affected past human populations of the region. The severest degradation, which occurred between A.D. 1250 and 1450, probably was causally related to numerous cultural changes that occurred at the end of the l3th century including the Anasazi abandonment of the Four Comers area. Projecting environmental patterns that characterized the last two millennia into the future indicates potential hazards to long term uranium mill waste disposal and containment and the potential and limitations of environmental restoration.

  11. Aftershock Decay Rates in the Iranian Plateau

    Science.gov (United States)

    Ommi, S.; Zafarani, H.; Zare, M.

    2016-07-01

    Motivated by the desire to have more information following the occurrence of damaging events, the main purpose of this article is to study aftershock sequence parameters in the Iranian plateau. To this end, the catalogue of the Iranian earthquakes between 2002 to the end of 2013 has been collected and homogenized among which 15 earthquakes have been selected to study their aftershock decay rates. For different tectonic provinces, the completeness magnitudes ( M c) of the earthquake catalogue have been calculated in different time intervals. Also, the M c variability in spatial and temporal windows has been determined for each selected event. For major Iranian earthquakes, catalogue of aftershocks has been collected thanks to three declustering methods: first, the classical windowing method of Gardner and Knopoff (Bull Seismol Soc Am 64:1363-1367, 1974); second, a modified version of this using spatial windowing based on the Wells and Coppersmith (Bull Seismol Soc Am 84:974-1002, 1994) relations; and third, the Burkhard and Grünthal (Swiss J Geosci 102:149-188, 2009) scheme. Effects of the temporal windows also have been investigated using the time periods of 1 month, 100 days, and 1 year in the declustering method of Gardner and Knopoff (Bull Seismol Soc Am 64:1363-1367, 1974). In the next step, the modified Omori law coefficients have been calculated for the 15 selected earthquakes. The calibrated regional generic model describing the temporal and magnitude distribution of aftershocks is of interest for time-dependent seismic hazard forecasts. The regional characteristics of the aftershock decay rates have been studied for the selected Iranian earthquakes in the Alborz, Zagros and Central Iran regions considering their different seismotectonics regimes. However, due to the lack of sufficient data, no results have been reported for the Kopeh-Dagh and Makran seismotectonic regions.

  12. Aged dissolved organic carbon exported from rivers of the Tibetan Plateau

    Science.gov (United States)

    Qu, Bin; Sillanpää, Mika; Kang, Shichang; Stubbins, Aron; Yan, Fangping; Aho, Kelly Sue; Zhou, Feng; Raymond, Peter A.

    2017-01-01

    The role played by river networks in regional and global carbon cycle is receiving increasing attention. Despite the potential of radiocarbon measurements (14C) to elucidate sources and cycling of different riverine carbon pools, there remain large regions such as the climate-sensitive Tibetan Plateau for which no data are available. Here we provide new 14C data on dissolved organic carbon (DOC) from three large Asian rivers (the Yellow, Yangtze and Yarlung Tsangpo Rivers) running on the Tibetan Plateau and present the carbon transportation pattern in rivers of the plateau versus other river system in the world. Despite higher discharge rates during the high flow season, the DOC yield of Tibetan Plateau rivers (0.41 gC m-2 yr-1) was lower than most other rivers due to lower concentrations. Radiocarbon ages of the DOC were older/more depleted (511±294 years before present, yr BP) in the Tibetan rivers than those in Arctic and tropical rivers. A positive correlation between radiocarbon age and permafrost watershed coverage was observed, indicating that 14C-deplted/old carbon is exported from permafrost regions of the Tibetan Plateau during periods of high flow. This is in sharp contrast to permafrost regions of the Arctic which export 14C-enriched carbon during high discharge periods. PMID:28552976

  13. High pre-industrial and modern Tibetan Plateau fire activity

    Science.gov (United States)

    Kehrwald, N. M.; Li, Q.; Wang, N.; Zennaro, P.; Zangrando, R.; Barbante, C.

    2013-12-01

    The South Asian brown cloud created from a mix of biomass burning and fossil fuel aerosols is warming the atmosphere between 5000 to 7000 meters above sea level (m asl) along the southern slope of the Himalaya. The extent to which this atmospheric brown cloud is transported up and over the 7000 to 8000 m asl ridge of the Himalaya and northward across the Tibetan Plateau is unknown. Intense Eastern Asian industry and associated coal burning may also export fossil fuel burning products to the Tibetan Plateau. In addition, local cooking, agricultural and natural fires emit combustion products that alter atmospheric chemistry and are deposited on glacier surfaces. It is essential to differentiate between the effects of fossil fuel and biomass burning across the Tibetan Plateau to determine if combustion products affect glacier surfaces and, by extension, glacier volume. The specific biomarker levoglucosan can only be produced by biomass burning at temperatures of 300°C or higher and is trapped and preserved in glaciers across the globe. This specificity may allow the possibility of differentiating between fossil fuel and biomass burning contributions when comparing levoglucosan concentrations with more general ice core combustion proxies such as black carbon. Here, we present a biomass burning record from the entire 164 m Muztag ice core (36.35°N; 87.17°E; 5780 m asl) and from a southwest to northeast transect of snow pits across the Tibetan Plateau. Multiple total organic carbon and dissolved organic carbon surface samples demonstrate organic carbon concentrations at or near detection limits. However, these samples have high levoglucosan concentrations suggesting that the biomass burning recorded in these sites may be from a regional rather than local source. The Tibetan Plateau levoglucosan concentrations are surprisingly substantially greater than Kilimanjaro levoglucosan concentrations, where Kilimanjaro is located in a relatively similar low-latitude high

  14. [The pathogenic ecology research on plague in Qinghai plateau].

    Science.gov (United States)

    Dai, Rui-xia; Wei, Bai-qing; Li, Cun-xiang; Xiong, Hao-ming; Yang, Xiao-yan; Fan, Wei; Qi, Mei-ying; Jin, Juan; Wei, Rong-jie; Feng, Jian-ping; Jin, Xing; Wang, Zu-yun

    2013-12-01

    To study the pathogenic ecology characteristics of plague in Qinghai plateau. Applied molecular biology techniques, conventional technologies and geographic information system (GIS) to study phenotypic traits, plasmid spectrum, genotype, infected host and media spectrum etc.of 952 Yersinia pestis strains in Qinghai plateau plague foci, which were separated from different host and media in different regions during 1954 to 2012. The ecotypes of these strains were Qingzang plateau (91.49%, 871/952),Qilian mountain (6.41%, 61/952) and Microtus fuscus (1.26%, 12/952).83.6% (796/952) of these strains contained all the 4 virulence factors (Fr1, Pesticin1,Virulence antigen, and Pigmentation), 93.26% (367/392) were velogenic strains confirmed by virulence test.725 Yersinia pestis strains were separated from Qinghai plateau plague foci carried 9 kinds of plasmid, among which 713 strains from Marmot himalayan plague foci carried 9 kinds of plasmid, the Mr were 6×10(6), 7×10(6), 23×10(6), 27×10(6), 30×10(6), 45×10(6), 52×10(6), 65×10(6) and 92×10(6) respectively. 12 Yersinia pestis strains were separated from Microtus fuscus plague foci carried only 3 kinds of plasmid, the Mr were 6×10(6), 45×10(6), 65×10(6). Meanwhile, the strains carrying large plasmid (52×10(6), 65×10(6) and 92×10(6)) were only distributed in particular geographical location, which had the category property. The research also confirmed that 841 Yersinia pestis strains from two kinds of plague foci in Qinghai plateau had 11 genomovars. The strains of Marmot himalayan plague foci were given priority to genomovar 5 and 8, amounted to 611 strains, genomovar 8 accounted for 56.00% (471/841), genomovar 5 accounted for 23.07% (194/841). Besides, 3 new genomovars, including new 1(62 strains), new 2(52 strains), new 3(48 strains) were newly founded, and 12 strains of Microtus fuscus plague foci were genomovar 14. The main host and media of Qinghai plateau plague foci directly affected the spatial

  15. Mantle plume or slab window?: Physical and geochemical constraints on the origin of the Caribbean oceanic plateau (Invited)

    Science.gov (United States)

    Kerr, A. C.; Hastie, A.

    2009-12-01

    The Caribbean oceanic plateau formed in the Pacific realm when it erupted onto the Farallon plate due to melting of (possibly) the Galapagos hotspot at ~93 Ma. The plateau was subsequently transported to the northeast and collided with the Great Arc of the Caribbean thus initiating subduction polarity reversal and the consequent tectonic emplacement of the Caribbean plate between the North and South American continents. The plateau represents a large outpouring of mafic volcanism, which has been interpreted as having formed by melting of a hot mantle plume. Conversely, some have suggested that a slab window could be involved in forming the plateau. However, the source regions of oceanic plateaus are distinct from N-MORB (the likely source composition for slab window mafic rocks). Furthermore, melt modelling using primitive (high-MgO) Caribbean oceanic plateau lavas from Curaçao, shows that the primary magmas of the plateau contained ~20 wt.% MgO and were derived from 30-32 % partial melting of a fertile peridotite source region which had a potential temperature (Tp) of 1564-1614 °C. Thus, the Caribbean oceanic plateau lavas are derived from decompression melting of a hot upwelling mantle plume with excess heat relative to ambient upper mantle. Extensional decompression partial melting of sub-slab asthenosphere in a slab window with an ambient mantle Tp cannot produce enough melt to form a plateau. The formation of the Caribbean oceanic plateau by melting of ambient upper mantle in, or close to, a slab window setting, is therefore, highly improbable. Reference Hastie, A.R., Kerr, A.C. 2010. Mantle plume or slab window?: Physical and geochemical constraints on the origin of the Caribbean oceanic plateau. Earth Science Reviews, in press.

  16. Insight into NE Tibetan Plateau expansion from crustal and upper mantle anisotropy revealed by shear-wave splitting

    Science.gov (United States)

    Huang, Zhouchuan; Tilmann, Frederik; Xu, Mingjie; Wang, Liangshu; Ding, Zhifeng; Mi, Ning; Yu, Dayong; Li, Hua

    2017-11-01

    The northeastern Tibetan plateau margin is the current expansion border, where growth of the plateau is ongoing. We analyze shear-wave splitting at ChinArray stations in the NE Tibetan Plateau and its margin with the stable North Chine Craton. The measurements provide important information on the seismic anisotropy and deformations patterns in the crust and upper mantle, which can be used to constrain the expansion mechanism of the plateau. Along the margin and within the craton, the dominant NW-SE fast polarization direction (FPD) is NW-SE, subparallel to the boundary between the plateau and the North China Craton. The shear-wave splitting measurements on the NE Tibetan Plateau itself generally reflect two-layer anisotropy. The lower-layer anisotropy (with NW-SE FPDs) is consistent in the whole region and FPDs are the same as those in the North China Craton. The upper-layer FPDs are parallel to crustal motion rather than surface structures within the high plateau. The two-layer anisotropy implies the presence of deformed Tibetan lithosphere above the underthrusting North China Craton. The NE Tibetan shows similar deformation patterns at the surface (inferred from GPS) and within the mantle (inferred from shear-wave splitting), but significant crustal anisotropy (parallel to crustal motion) requires mid-lower crustal channel flow or detachment to drive further tectonic uplift of the plateau.

  17. Systeemomschrijving “Plateau 2.0”

    NARCIS (Netherlands)

    Hoofs, Anita

    2017-01-01

    En varkenshok met plateau is een hok waarin varkens vrij beschikken over twee verblijfsniveaus, één op de begane grond en één op het plateau. Varkens kunnen gemakkelijk het plateau op - en aflopen via een trap. Bij toepassing van een plateau, dat voldoet aan de systeemomschrijving, mag het

  18. Spatiotemporal variations in precipitation across the Chinese Mongolian plateau over the past half century

    Science.gov (United States)

    Gao, Ruizhong; Li, Fengling; Wang, Xixi; Liu, Tingxi; Du, Dandan; Bai, Yong

    2017-09-01

    Precipitation, as affected by climate change, controls the growth of steppe grasses and grassland degradation/desertification in semiarid/arid regions, including the Chinese Mongolian plateau. This study examined the spatial variability and temporal trends in precipitation across the plateau in terms of four indexes: total precipitation (P), number of rainy days (Wd), number of precipitation events (N), and average precipitation intensity (Imean). Although seldom published in the literature, this information is vital for efforts to develop adaptive measures to sustain this vulnerable pasture economy. Seven hundred time series were formulated by preprocessing the data on daily precipitation over the period 1960 to 2012 at 25 weather stations scattered across the plateau. The results indicated that although the plateau was becoming drier overall, the intensity of storm events increased markedly, as indicated by decreasing trends for P, Wd and N but an increasing trend for Imean. On average, P decreased by 0.65 mm yr- 1 over the study period, while Imean increased by 0.2 mm d- 1 yr- 1. Across the plateau, the western part was becoming wetter, while the central-eastern part was becoming drier. This spatial discrepancy in the precipitation trends was particularly obvious in the winter dry season, with Imean tending to increase more rapidly in the central-eastern than western part, especially in the spring dry season. It is expected that these trends will continue, thus further challenging the already vulnerable eco-environment of the plateau.

  19. Climatic Effects of Black Carbon Aerosols Over the Tibetan Plateau

    Science.gov (United States)

    He, Cenlin

    Black carbon (BC), also known as soot, has been identified as the second most important anthropogenic emissions in terms of global climate forcing in the current atmosphere. Ample evidence has shown that BC deposition is an important driver of rapid snow melting and glacier retreat over the Tibetan Plateau, which holds the largest snow/ice mass outside polar regions. However, the climatic effects of BC over the Tibetan Plateau have not been thoroughly investigated in such a manner as to understand, quantify, and reduce large uncertainties in the estimate of radiative and hydrological effects. Thus, this Ph.D. study seeks to understand and improve key processes controlling BC life cycle in global and regional models and to quantify BC radiative effects over the Tibetan Plateau. First, the capability of a state-of-the-art global chemical transport model (CTM), GEOS-Chem, and the associated model uncertainties are systematically evaluated in simulating BC over the Tibetan Plateau, using in situ measurements of BC in surface air, BC in snow, and BC absorption optical depth. The effects of three key factors on the simulation are also delineated, including Asian anthropogenic emissions, BC aging process, and model resolution. Subsequently, a microphysics-based BC aging scheme that accounts for condensation, coagulation, and heterogeneous chemical oxidation processes is developed and examined in GEOS-Chem by comparing with aircraft measurements. Compared to the default aging scheme, the microphysical scheme reduces model-observation discrepancies by a factor of 3, particularly in the middle and upper troposphere. In addition, a theoretical BC aging-optics model is developed to account for three typical evolution stages, namely, freshly emitted aggregates, coated BC by soluble material, and BC particles undergoing further hygroscopic growth. The geometric-optics surface-wave (GOS) approach is employed to compute the BC single-scattering properties at each aging stage

  20. Constant Chinese Loess Plateau dust source since the Late Miocene

    Science.gov (United States)

    Bird, Anna; Millar, Ian; Stevens, Thomas; Rodenburg, Tanja; Rittner, Martin; Vermeesch, Pieter; Lu, Huayu

    2017-04-01

    The dramatic deepening of northern hemisphere glaciation at the Pliocene-Pleistocene boundary is accompanied by major changes in global climate. The role of the global atmospheric dust cycle in this event is not clear; in particular, whether, changes in the dust cycle influenced climates change, or resulted from it. Miocene and Quaternary wind-blown Chinese loess records past dust-cycle history, influences of aridification and monsoon circulation. Previous work on the vast Chinese Loess Plateau is in conflict over whether changes in dust source occur at the Pliocene-Pleistocene boundary (2.59 Ma), or at 1.2 Ma, despite these intervals marking major shifts in monsoon dynamics (Sun 2005; Nie et al. 2014a). Here we present Sr, Nd and Hf isotopic data from multiple sites and show that the dust source remains the same across these boundaries. The use of isotope tracers from multiple sites allows us to demonstrate that shifts in sediment geochemistry can be explained by grain-size and weathering changes. Nd and Hf isotopes show that the dust was dominantly sourced from the Tibetan Plateau, with some input from bedrock underlying the Badain Jaran/Tengger deserts. This shows that a major established and constant dust source on the northern Tibetan Plateau has been active and unchanged since the late Miocene, despite dramatically changing climate conditions. Changes in loess accumulation are therefore a function of climate change in the Tibetan Plateau source regions rather than due to expanding source areas controlled by aridification over a widening area over the Pliocene and Quaternary.

  1. Colorado Plateau Rapid Ecoregion Assessment Data Catalog

    Data.gov (United States)

    Bureau of Land Management, Department of the Interior — Datasets used in the analysis of the Colorado Plateau (COP) Rapid Ecoregion Assessment (REA).They can be downloaded via a layer package (lpk, similar to a zip file...

  2. Uplift of the Colorado Plateau due to lithosphere attenuation during Laramide low-angle subduction

    Science.gov (United States)

    Spencer, J.E.

    1996-01-01

    The Colorado Plateau is blanketed by Phanerozoic marine and nonmarine strata as young as Cretaceous that are now exposed at elevations of about 2 km. Crustal thickening due to magmatism and horizontal crustal shortening was far less than necessary to cause this uplift, which is commonly attributed to the consequences of mantle lithosphere thinning and heating. The Colorado Plateau and the midcontinent region around Iowa consist of Precambrian bedrock overlain by a similar amount of Paleozoic platformal strata, and thus both regions once had similar lithospheric buoyancy. Mesozoic sedimentation increased the crustal thickness and lithospheric buoyancy of the Colorado Plateau relative to the midcontinent region. Backstripping calculations yield elevation without these sediments and lead to a calculated elevation difference between the two areas of about 1200 m, which represents unexplained plateau uplift. Review of constraints on uplift timing finds little support for a late Cenozoic uplift age and allows early to middle Cenozoic uplift, which is consistent with uplift mechanisms related to low-angle subduction that ended in the middle Cenozoic. Finite element heat flow calculations of low-angle subduction and lithosphere attenuation, using a range of initial lithosphere thicknesses and degree of attenuation, indicate that required uplift can result from tectonic removal of about 120 km of mantle lithosphere from an initially 200-km-thick lithosphere. This allows for partial preservation of North American mantle lithosphere with its distinctive isotopic signature in some late Cenozoic volcanic rocks and is consistent with normal Pn velocities in the uppermost mantle beneath the plateau.

  3. Corrections to holographic entanglement plateau

    Science.gov (United States)

    Chen, Bin; Li, Zhibin; Zhang, Jia-ju

    2017-09-01

    We investigate the robustness of the Araki-Lieb inequality in a two-dimensional (2D) conformal field theory (CFT) on torus. The inequality requires that Δ S = S( L) - | S( L - ℓ) - S( ℓ)| is nonnegative, where S( L) is the thermal entropy and S( L - ℓ), S( ℓ) are the entanglement entropies. Holographically there is an entanglement plateau in the BTZ black hole background, which means that there exists a critical length such that when ℓ ≤ ℓ c the inequality saturates Δ S =0. In thermal AdS background, the holographic entanglement entropy leads to Δ S = 0 for arbitrary ℓ. We compute the next-to-leading order contributions to Δ S in the large central charge CFT at both high and low temperatures. In both cases we show that Δ S is strictly positive except for ℓ = 0 or ℓ = L. This turns out to be true for any 2D CFT. In calculating the single interval entanglement entropy in a thermal state, we develop new techniques to simplify the computation. At a high temperature, we ignore the finite size correction such that the problem is related to the entanglement entropy of double intervals on a complex plane. As a result, we show that the leading contribution from a primary module takes a universal form. At a low temperature, we show that the leading thermal correction to the entanglement entropy from a primary module does not take a universal form, depending on the details of the theory.

  4. The Altiplano-Puna Plateau as an Analog for Mars

    Science.gov (United States)

    de Silva, S. L.; Byrnes, J. M.; Crown, D. A.; Zimbelman, J. R.; Jimenez, N.; Bills, B. G.

    2002-12-01

    The Altiplano-Puna Plateau of the Central Andes of Bolivia has experienced a climatic and geologic evolution that has resulted in an enticing array of potential Martian analog geologic environments and features. Elevated ~3 ? 4km above the adjacent Atacama desert, the Altiplano-Puna is the highest plateau in the world associated with extensive volcanism; it is second only to Tibet in height and extent. The high elevation adds extreme cold, wind, and lower atmospheric pressure to a hyper-arid climate making this region a compelling analog environment for Mars. The plateau is dominated by the Altiplano basin, which developed as a major intermontane basin since at least 25Ma. This is flanked by major volcanic provinces to the east and south. To the south is the Altiplano-Puna Volcanic Complex (APVC) where regionally extensive ignimbrite sheets and associated eruptive centers are amongst the largest known volcanic features in the world. The region has proven to be an excellent natural laboratory for remote sensing and field-based studies of volcanism. The extreme cold, wind, and the wide diurnal temperature range, results in geomorphic expressions dominated by physical weathering and aeolian erosion. These factors make this region one of the premier analog environments for Martian features like Amazonis Planitia, and Hadriaca, Alba, and Tyrrhena paterae, as well as the enigmatic Medusa Fossae Formation (MFF) materials. Large ignimbrite shields, are prominent features of volcanic geology of the plateau and are the subject of an ongoing terrestrial analog study for the MFF. The Altiplano basin preserves a long Pleistocene lake history recorded in a well-preserved lake shore geomorphology consisting of both erosional and depositional features. These features are easily identified and studied in the field and on remotely sensed images and may lend valuable insight into the debate over putative paleoshorelines in the northern plains of Mars. Throughout the basin are several

  5. Climatic variability of the column ozone over the Iranian plateau

    Science.gov (United States)

    Mousavi, Seyyed Shafi; Farajzadeh, Manuchehr; Rahimi, Yousef Ghavidel; Bidokhti, Abbasali Aliakbari

    2017-06-01

    This study analyzes the total ozone column (TOC) variability over the Iranian plateau (Esfahan) from 1978 to 2011. Results show that the annual average of TOC in Esfahan tends to decrease with time, which is strongly dependent on the season, with maximum values during the winter-spring months (more than 2.2 %/decade). By applying a defined threshold that includes the TOC monthly -2 σ, it is found that the maximum occurrence of low ozone events (LOEs) tends to be more frequent in the second half of year with about four-fifth of the observed LOEs (last summer, autumn, and early winter). During two cases of LOE, the tropopause height (TH) was uplifted 2-4 km with temperature of 10 °C colder than the long-term mean, and the synoptic pattern was characterized by high-pressure systems in UTLS region. The extreme LOEs were consistent with the horizontal transport of ozone-poor air toward the Iranian plateau and vertical advection in UTLS region. The former mechanism plays a primary role in formation of extreme LOEs based on the observed TOC reductions during previous days over the source regions (Sahara desert and Himalaya region). Day-to-day variations of maximum UV index during LOEs show that by a decrease in TOC 14 %, while the aerosol optical depth (AOD) in the cloudless condition reach their lowest rates (lower than 0.3), UV radiation exceeds very high and extreme levels in late winter and mid-spring, respectively.

  6. Morpho-Tectonic Evidence of Multi-Stage Uplift History of the Southeastern Ethiopian Plateau, the East African Rift System

    Science.gov (United States)

    Xue, L.; Abdelsalam, M. G.

    2016-12-01

    We used Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) to extract geomorphic proxies (normalized steepness, stream length gradient, shape factor, and valley height ratio) for the Southwestern Ethiopian Plateau. We also imaged the Moho beneath the plateau using two-dimensional power radially-average power spectral analysis of World Gravity Model (WGM 2012) satellite gravity data. Our aim is to examine the uplift history of the plateau that might be associated with the uprising of the Afar mantle plume and opening of the East African Rift System. This plateau, which is bounded by the Afar Depression in the north and the Main Ethiopian Rift in the east, exposes Cenozoic volcanic rocks at the top underlain by Mesozoic sedimentary rocks. Studies in the Northwestern Ethiopian Plateau resulted in two contrasting models for explaining the uplift history of the region. Thermogeochronology studies suggest a continuous and steady uplift rate since 30 Ma possibly driven by the ascending Afar mantle plume. While, the interpretation of incision of drainage systems in the plateau suggests three stage and accelerated uplift. Our work found two areas with high rate of tectonic uplift located around the Mendebo and the Ahmar mountains. These regions show two distinct phases of uplift of the Southeastern Ethiopian Plateau. Also, a chronological framework has been provided to the knickpoint migration and associated Quaternary basalt event by knickpoint celerity model.

  7. Iron Speciation in Proximity to an Active Volcanic Hotspot, Kerguelen Plateau, Southern Ocean

    Science.gov (United States)

    Holmes, T.; Wuttig, K.; Chase, Z.; van der Merwe, P.; Townsend, A.; Bowie, A. R.

    2016-12-01

    Low iron (Fe) concentrations limit biological productivity in over a third of the world's oceans. The Southern Ocean (SO) is the largest of these regions of Fe deficiency. However, within the Indian sector of the SO lays an oasis of relatively Fe rich waters overlaying the Kerguelen Plateau. At the southern part of the central Kerguelen plateau is an active volcanic hotspot, hosting two volcanically active islands, Heard and MacDonald (HIMI), the former of which is largely covered by glaciers. Waters in the region are subject to an intense mixing regime, caused by shallow bathymetry and the location of the plateau in the path of strong currents associated with the polar front. Fed by the Fe rich waters formed on the plateau, a plankton bloom on the order of thousands of square kilometres forms in the lee of the plateau annually each summer. Here we present dissolved iron (dFe), dissolved iron(II) (dFe(II)) and hydrogen peroxide (H2O2) data from waters surrounding HIMI on the central Kerguelen Plateau collected on RV Investigator voyage IN2016_V01 in early 2016. Analysis was performed at sea using three separate flow injection - chemiluminescence instruments. Two broadly zonal transects revealed that dFe was present in limiting concentrations (island and accounted for up to 30% of the total dFe. We also observed an intense mixing regime homogenising short-lived Fe(II) and H2O2 species throughout the water column in shallow areas of the plateau. Our results revealed varying Fe speciation patterns between the islands indicating multiple Fe sources around HIMI, including reducing hydrothermal, sedimentary and glacial sources.

  8. Sensitivity of the Colorado Plateau to Change: Climate, Ecosystems, and Society

    Directory of Open Access Journals (Sweden)

    Susan Schwinning

    2008-12-01

    Full Text Available The Colorado Plateau is located in the interior, dry end of two moisture trajectories coming from opposite directions, which have made this region a target for unusual climate fluctuations. A multi-decadal drought event some 850 years ago may have eliminated maize cultivation by the first human settlers of the Colorado Plateau, the Fremont and Anasazi people, and contributed to the abandonment of their settlements. Even today, ranching and farming are vulnerable to drought and struggle to persist. The recent use of the Colorado Plateau primarily as rangeland has made this region less tolerant to drought due to unprecedented levels of surface disturbances that destroy biological crusts, reduce soil carbon and nitrogen stocks, and increase rates of soil erosion. The most recent drought of 2002 demonstrated the vulnerability of the Colorado Plateau in its currently depleted state and the associated costs to the local economies. New climate predictions for the southwestern United States include the possibility of a long-term shift to warmer, more arid conditions, punctuated by megadroughts not seen since medieval times. It remains to be seen whether the present-day extractive industries, aided by external subsidies, can persist in a climate regime that apparently exceeded the adaptive capacities of the Colorado Plateau's prehistoric agriculturalists.

  9. Enhanced recovery after surgery program in patients from Tibet Plateau undergoing surgeries for hepatic alveolar echinococcosis.

    Science.gov (United States)

    Yang, Mengchang; Su, Wenjie; Deng, Xiaofan; Deng, Jia; Li, Peng; Li, Xiangkui

    2017-11-01

    Hepatic alveolar echinococcosis (HAE) is a severe and common parasitic disease in Tibetan Plateau of China. The infected patients have to move to plain areas to receive treatments due to the poor medical conditions in plateau areas. Our aim was to investigate the application of Enhanced Recovery after Surgery (ERAS) program in perioperative management for HAE patients from Tibet Plateau and the notes for patients with landform changes. A total of 89 HAE patients from Tibet Plateau (altitude: average of 4500 m) prior received adaptive treatments at the cooperative hospital (altitude: 1500-2000 m) and accepted surgery at plain regions (altitude: 200-400 m). The patients in ERAS group received ERAS program care and patients in conventional management group received conventional care during perioperative period. Patients in ERAS group displayed significant shorter hospital stay and shorter time for recovery of gurgling compared with conventional management group (ERAS group versus conventional management group: 10.48 ± 3.525 d versus 20.29 ± 8.632 d; 1.56 ± 1.236 d versus 2.8 ± 1.19 d; all P Plateau need to receive adaptive treatments for landform changes before receiving surgeries at plain regions. ERAS program is effective and safe for Tibetan HAE patients during perioperative period. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. New Exploration of North Kerguelen Plateau Margins : Constraints for the Australia-Antarctica Separation

    Science.gov (United States)

    Courrèges, E.; Vially, R.; Roest, W. R.; Patriat, M.; Patriat, P.; Loubrieu, B.; Lecomte, J.-C.; Schaming, M.; Schmitz, J.; Maia, M.

    2009-04-01

    France ratified the United Nations Convention on the Law of the Sea in 1996, and has since undertaken an ambitious program of bathymetric and seismic data acquisition (EXTRAPLAC Program) to support claims for the extension of the legal continental shelf, in accordance with Article 76 of this convention. For this purpose, three oceanographic surveys took place on board of the R/V Marion Dufresne II, operated by the French Polar Institute, on the Kerguelen Plateau, in the Southern Indian Ocean: MD137-Kergueplac1 (February 2004), MD150-Kergueplac2 (October 2005) and MD165-Kergueplac3 (January 2008). Thus, more than 20 000 km of multibeam bathymetric, magnetic and gravimetric profiles, and almost 6 000 km of seismic profiles where acquired during a total of 62 days of survey in the study area. Ifremer's "rapid seismic" system was used, comprised of 4 guns and a 24 trace digital streamer, operated at speeds up to 10 knots. In addition to its use for the Extraplac Program, the data set issued from these surveys provides the opportunity to improve our knowledge of the structure of the Kerguelen Plateau and more particularly of its complex margins. In this poster, we show different kinds of data. The high resolution bathymetry (200 m grid) data set allows us to specify the irregular morphology of the sea floor in the north Kerguelen Plateau region, characterised by ridges and volcano chains that intersect the oceanic basin on its NE edge. The seismic profiles show that the acoustic basement of the plateau is not much tectonised, and displays a very smooth texture, clearly contrasting it from typical oceanic basement. Both along the edge of the plateau and in the abyssal plain, sediments have variable thicknesses. The sediments on the margin of the plateau are up to 1200 meters thick and display irregular crisscross patterns, suggesting the presence of important bottom currents. An important concentration of new magnetic data, in a key area (Northern Kerguelen Platerau) and

  11. [Soil particle size distribution and its fractal dimension among degradation sequences of the alpine meadow in the source region of the Yangtze and Yellow River, Qinghai-Tibetan Plateau, China].

    Science.gov (United States)

    Wei, Mao-Hong; Lin, Hui-Long

    2014-03-01

    The alpine meadow in the source region of the Yangtze and Yellow River is suffering serious deterioration. Though great efforts have been put into, the restoration for the degraded grassland is far from being effective, mainly due to poor understanding of the degradation mechanism of alpine meadow in this region. In order to clarify the formation mechanism of degradation grassland and provide the new ideas for restoration, degradation sequences of the alpine meadow in the source region of the Yangtze and Yellow River were taken as target systems to analyze the soil particle size distribution, the fractal dimension of the soil particle size, and the relationship between soil erosion modulus and fractal dimension. The results showed that, with increasing grassland degradation, the percentage contents of clay increased while the percentage contents of silt sand and very fine sand showed a decreasing trend. The fractal dimension presented a positive correlation with clay among the degradation sequences while negative correlations were found with very fine sand and silt sand. The curvilinear regression of fractal dimension and erosion modulus fitted a quadratic function. Judged by the function, fractal dimension 2.81 was the threshold value of soil erosion. The threshold value has an indicative meaning on predicting the breakout of grazing-induced erosion and on restoration of the degraded grassland. Taking fractal dimension of 2.81 as the restoration indicator, adoption of corresponding measures to make fractal dimension less than 2.81, would an effective way to restore the degradation grassland.

  12. A Comparative Study of the Electrical Structure of Circum Tibetan Plateau Orogenic Belts and its Tectonic Implications

    Science.gov (United States)

    Jin, Sheng; Zhang, Letian; Wei, Wenbo; Ye, Gaofeng; Jing, Jianen; Dong, Hao; Xie, Chengliang; Yin, Yaotian

    2017-04-01

    blocked and piled up along the eastern margin of the plateau due to the block of the Sichuan Basin, which further result in the uplift and expansion of the eastern Tibetan plateau. The northeastern and northern margins of the Tibetan plateau is bounded by large scale left-lateral strike-slip Haiyuan and Altyn Tagh faults. In these regions, the plateau interacts with the surrounding stable blocks in a way of oblique strike-slip. The deformation of the northern Tibetan lithosphere is dominated by crustal thickening, where no features of decoupling or large scale underthrusting were seen. Crustal conductors in these regions are generally not very well connected, which suggest the absence of crustal flow. Deep metamorphism fluids could be an alternative interpretation of the crustal conductors in these regions. * This work was jointly supported by the grants from Project SinoProbe-02-04 and National Natural Science Foundation of China (41404060).

  13. New Exploration of Kerguelen Plateau Margins

    Science.gov (United States)

    Vially, R.; Roest, W. R.; Loubrieu, B.; Courreges, E.; Lecomte, J.; Patriat, M.; Pierre, D.; Schaming, M.; Schmitz, J.

    2008-12-01

    France ratified the United Nations Convention on the Law of the Sea in 1996, and has since undertaken an ambitious program of bathymetric and seismic data acquisition (EXTRAPLAC Program) to support claims for the extension of the legal continental shelf, in accordance with Article 76 of this convention. For this purpose, three oceanographic surveys took place on board of the R/V Marion Dufresne II on the Kerguelen Plateau, in Southern Indian Ocean: MD137-Kergueplac1 (February 2004), MD150-Kergueplac2 (October 2005) and MD165-Kergueplac3 (January 2008), operated by the French Polar Institute. Thus, more than 20 000 km of multibeam bathymetric, magnetic and gravimetric profiles, and almost 6 000 km of seismic profiles where acquired during a total of 62 days of survey in the study area. Ifremer's "rapid seismic" system was used, comprised of 4 guns and a 24 trace digital streamer, operated at speeds up to 10 knots. In addition to its use for the Extraplac Program, the data set issued from these surveys gives the opportunity to improve our knowledge of the structure of the Kerguelen Plateau and more particularly of its complex margins. In this poster, we will show the high resolution bathymetry (200 m) data set, that allows us to specify the irregular morphology of the sea floor in the north Kerguelen Plateau, characterised by ridges and volcanoes chains, radial to the plateau, that intersect the oceanic basin on the NE edge of the Kerguelen Plateau. We will also show magnetic and gravity data, which help us to understand the setting up of the oceanic plateau and the kinematics reconstructions. The seismic profiles show that the acoustic basement of the plateau is not much tectonised, and displays a very smooth texture, clearly contrasting it from typical oceanic basement. Both along the edge of the plateau as in the abyssal plain, sediments have variable thicknesses. The sediments on the margin of the plateau are up to 1200 meters thick and display irregular

  14. Evolution of the Southern Guinea Plateau: Implications on Guinea-Demerara Plateau formation using insights from seismic, subsidence, and gravity data

    Science.gov (United States)

    Olyphant, Jared R.; Johnson, Roy A.; Hughes, Amanda N.

    2017-10-01

    The Guinea Plateau (offshore Guinea) and its conjugate, the Demerara Plateau (offshore French Guiana), comprise two of the most prominent passive continental margins in the Atlantic Ocean. The conjugate plateaus formed as a result of two periods of rifting, the Jurassic opening of the Central Atlantic Ocean and the northward-propagating Cretaceous opening of the Southern Atlantic Ocean. Although several studies are published on the Demerara Plateau that explain the evolution of its multi-rift history and the effect of rifting on its distinct geometry, the Guinea Plateau, and in particular its south-eastern margin, remain relatively unexplored in the literature. Here we present interpretations of the structure and evolution of the Guinea Plateau using recent 2-D and 3-D seismic-reflection data collected at the intersection of the southern and eastern margins. We substantiate our study with calculated subsidence curves at four locations along the southern margin, as well as two 2-D gravity forward models along regional seismic-reflection profiles to estimate stretching factors (β) and crustal thicknesses. We combine our results with previous studies concerning the south-western Guinea margin, and compare them to published interpretations regarding the conjugate margins of the Demerara Plateau. The resolved amounts of rift-related volcanism, listric-style normal faults, and moderate stretching factors suggest that a component of upper-crustal asymmetry (simple shear) and depth-dependent stretching may have persisted at the Demerara-Guinea conjugate margins during Cretaceous rifting of the equatorial segment of the Southern Atlantic Ocean.

  15. Understanding a rapid transition in subistence regimes on the Tibetan Plateau

    Science.gov (United States)

    DAlpoim Guedes, J. A.

    2016-12-01

    Moving agriculture into the highlands of the Tibetan Plateau, was a challenging process. Short growing seasons, cold winters and spring frost mean that the Tibetan plateau presented considerable challenges to the movement of domesticates into this region. In this paper, we describe the creation and employment of crop niche models aimed at outlining the constraints associated with practicing a range of different crops on the Tibetan plateau and in the foothills of the Himalayas. These models contribute to explaining a profound change in both settlement patterns and in subsistence regimes on the Eastern Tibetan Plateau when a shift from a millet-based agriculture to wheat and barley based agro-pastoralism took place c. 2000 cal. BC. Using a model that predicts the changing distribution of crop niches across the area, we examine the role that changes in ancient climate could have played in the reversal of subsistence practices in this area. We argue that cooling temperatures at the end of the Holocene climatic optimum made it impossible for early farmers on the margins of the Tibetan Plateau to continue growing millets. It was only when two frost tolerant crops: wheat and barley arrived on the Plateau that agriculture was able to once again become implanted in select river valleys of the Plateau. We also identify the little ice age as a period that likely had a substantial impact on Tibetan agriculture. Using a range of different projected scenarios of climate change, we ask what insights earlier and warmer periods of time may hold for informing new subsistence strategies on the roof of the world.

  16. Combining CHAMP and Swarm Satellite Data to Invert the Lithospheric Magnetic Field in the Tibetan Plateau.

    Science.gov (United States)

    Qiu, Yaodong; Wang, Zhengtao; Jiang, Weiping; Zhang, Bingbing; Li, Fupeng; Guo, Fei

    2017-01-26

    CHAMP and Swarm satellite magnetic data are combined to establish the lithospheric magnetic field over the Tibetan Plateau at satellite altitude by using zonal revised spherical cap harmonic analysis (R-SCHA). These data are integrated with geological structures data to analyze the relationship between magnetic anomaly signals and large-scale geological tectonic over the Tibetan Plateau and to explore the active tectonic region based on the angle of the magnetic anomaly. Results show that the model fitting error is small for a layer 250-500 km high, and the RMSE of the horizontal and radial geomagnetic components is better than 0.3 nT. The proposed model can accurately describe medium- to long-scale lithospheric magnetic anomalies. Analysis indicates that a negative magnetic anomaly in the Tibetan Plateau significantly differs with a positive magnetic anomaly in the surrounding area, and the boundary of the positive and negative regions is generally consistent with the geological tectonic boundary in the plateau region. Significant differences exist between the basement structures of the hinterland of the plateau and the surrounding area. The magnetic anomaly in the Central and Western Tibetan Plateau shows an east-west trend, which is identical to the direction of the geological structures. The magnetic anomaly in the eastern part is arc-shaped and extends along the northeast direction. Its direction is significantly different from the trend of the geological structures. The strongest negative anomaly is located in the Himalaya block, with a central strength of up to -9 nT at a height of 300 km. The presence of a strong negative anomaly implies that the Curie isotherm in this area is relatively shallow and deep geological tectonic activity may exist.

  17. The plateau zokors' learning and memory ability is related to the high expression levels of foxP2 in the brain.

    Science.gov (United States)

    Ma, Ben-Yuan; Wei, Lian; Sun, Sheng-Zhen; Wang, Duo-Wei; Wei, Deng-Bang

    2014-04-25

    Plateau zokor (Myospalax baileyi) is a subterranean mammal. Plateau zokor has high learning and memory ability, and can determine the location of blocking obstacles in their tunnels. Forkhead box p2 (FOXP2) is a transcription factor implicated in the neural control of orofacial coordination and sensory-motor integration, particularly with respect to learning, memory and vocalization. To explore the association of foxP2 with the high learning and memory ability of plateau zokor, the cDNA of foxP2 of plateau zokor was sequenced; by using plateau pika as control, the expression levels of foxP2 mRNA and FOXP2 protein in brain of plateau zokor were determined by real-time PCR and Western blot, respectively; and the location of FOXP2 protein in the brain of plateau zokor was determined by immunohistochemistry. The result showed that the cDNA sequence of plateau zokor foxP2 was similar to that of other mammals and the amino acid sequences showed a relatively high degree of conservation, with the exception of two particular amino acid substitutions [a Gln (Q)-to-His (H) change at position 231 and a Ser (S)-to-Ile (I) change at position 235]. Higher expression levels of foxP2 mRNA (3-fold higher) and FOXP2 protein (>2-fold higher) were detected in plateau zokor brain relative to plateau pika brain. In plateau zokor brain, FOXP2 protein was highly expressed in the cerebral cortex, thalamus and the striatum (a basal ganglia brain region). The results suggest that the high learning and memory ability of plateau zokor is related to the high expression levels of foxP2 in the brain.

  18. Petrogenesis of mafic collision zone magmatism: The Armenian sector of the Turkish-Iranian Plateau

    NARCIS (Netherlands)

    Neill, I.; Meliksetian, K.; Allen, M.B.; Navasardyan, G.; Kuiper, K.F.

    2015-01-01

    The Turkish-Iranian Plateau grew after the Middle Miocene following the initial Paleogene Arabia-Eurasia collision. Authors attribute uplift to break-off of the southern Neo-Tethys slab beneath the Bitlis-Zagros Suture at ~. 15-10. Ma, coupled with continued plate convergence and regional crustal

  19. Effects of biochar addition on evaporation in the five typical Loess Plateau soils

    Science.gov (United States)

    Soil evaporation is the main route of soil moisture loss and often exceeds precipitation in the arid and semi-arid regions of the Loess Plateau. This study was conducted to determine whether biochar addition could reduce soil evaporation in drylands. We measured the evaporative loss in five typical ...

  20. Biogeography of cryoconite bacterial communities on glaciers of the Tibetan Plateau.

    Science.gov (United States)

    Liu, Yongqin; Vick-Majors, Trista J; Priscu, John C; Yao, Tandong; Kang, Shichang; Liu, Keshao; Cong, Ziyuang; Xiong, Jingbo; Li, Yang

    2017-06-01

    Cryoconite holes, water-filled pockets containing biological and mineralogical deposits that form on glacier surfaces, play important roles in glacier mass balance, glacial geochemistry and carbon cycling. The presence of cryoconite material decreases surface albedo and accelerates glacier mass loss, a problem of particular importance in the rapidly melting Tibetan Plateau. No studies have addressed the microbial community composition of cryoconite holes and their associated ecosystem processes on Tibetan glaciers. To further enhance our understanding of these glacial ecosystems on the Tibetan Plateau and to examine their role in carbon cycling as the glaciers respond to climate change, we explored the bacterial communities within cryoconite holes associated with three climatically distinct Tibetan Plateau glaciers using Illumina sequencing of the V4 region of the 16S rRNA gene. Cryoconite bacterial communities were dominated by Cyanobacteria, Chloroflexi, Betaproteobacteria, Bacteroidetes and Actinobacteria. Cryoconite bacterial community composition varied according to their geographical locations, exhibiting significant differences among glaciers studied. Regional beta diversity was driven by the interaction between geographic distance and environmental variables; the latter contributed more than geographic distance to the variation in cryoconite microbial communities. Our study is the first to describe the regional-scale spatial variability and to identify the factors that drive regional variability of cryoconite bacterial communities on the Tibetan Plateau. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Long-term streamflow response to climatic variability in the Loess Plateau, China

    Science.gov (United States)

    Shenping Wang; Zhiqiang Zhang; Ge Sun; Steven G. McNulty; Huayong Zhang; Jianlao Li; Manliang Zhang

    2008-01-01

    The Loess Plateau region in northwestern China has experienced severe water resource shortages due to the combined impacts of climate and land use changes and water resource exploitation during the past decades. This study was designed to examine the impacts of climatic variability on streamflow characteristics of a 12-km2 watershed near Tianshui City, Gansu Province...

  2. Regional assessment of aquifers for thermal energy storage. Volume 1. Regions 1 through 6

    Energy Technology Data Exchange (ETDEWEB)

    1981-06-01

    This volume contains information on the geologic and hydrologic framework, major aquifers, aquifers which are suitable and unsuitable for annual thermal energy storage (ATES) and the ATES potential of the following regions of the US: the Western Mountains; Alluvial Basins; Columbia LAVA Plateau; Colorado Plateau; High Plains; and Glaciated Central Region. (LCL)

  3. Peopling the Tibetan plateau: insights from archaeology.

    Science.gov (United States)

    Aldenderfer, Mark

    2011-01-01

    Recent studies of the genome of modern Tibetans have revealed the existence of genes thought to provide an adaptive advantage for life at high elevation. Extrapolating from this discovery, some researchers now argue that a Tibetan-Han split occurred no more than 2750 yr ago. This date is implausible, and in this paper I review the archaeological data from the Tibetan plateau as one means by which to examine the veracity of this assertion. Following a review of the general state of knowledge of Tibetan prehistory, which is unfortunately only at its beginnings, I first examine the data that speak to the initial peopling of the plateau and assess the evidence that traces of their presence can be seen in modern Tibetans today. Although the data are sparse, both archaeology and genetics suggest that the plateau was occupied in the Late Pleistocene, perhaps as early as 30,000 yr ago, and that these early peoples have left a genetic signature in modern Tibetans. I then turn to the evidence for later migrations and focus on the question of the timing of the establishment of permanent settled villages on the plateau. Three areas of the plateau-northeastern Qinghai, extreme eastern Tibet, and the Yarlung Tsangpo valley-have evidence of permanent settlements dating from ca. 6500, 5900, and 3750 yr ago, respectively. These data are not consonant with the 2750 yr ago date for the split and suggest at a minimum that the plateau has been occupied substantially longer and, further, that multiple migrations at different times and from different places have created a complex mosaic of population history. © Mary Ann Liebert, Inc.

  4. Plateau iris secondary to iridociliary cysts.

    Science.gov (United States)

    Vila-Arteaga, J; Díaz-Céspedes, R A; Suriano, M M

    2015-11-01

    We present a case of plateau iris and glaucoma due to multiple unilateral iridociliary cysts. The patient was treated with iridotomy Nd: YAG laser and 360° iridoplasty, without achieving pressure control. Phacoemulsification improved the hypertension. Dynamic gonioscopy and OCT of the anterior chamber was also performed before and after treatment. Iridociliary cysts are a benign condition that can cause iris plateau configuration, and can produce a difficult to treat ocular hypertension. Cystotomy, peripheral iridoplasty, and other treatments have been proposed. Copyright © 2014 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  5. Plateau-insulator transition in graphene

    Energy Technology Data Exchange (ETDEWEB)

    Amado, M; Diez, E; Caridad, J M [Laboratorio de Bajas Temperaturas, Universidad de Salamanca, E-37008 Salamanca (Spain); Lopez-Romero, D [CT-ISOM, Universidad Politecnica de Madrid, E-28040 Madrid (Spain); Rossella, F; Dionigi, F; Bellani, V [Dipartimento di Fisica ' A Volta' and CNISM, Universita degli studi di Pavia, I-27100 Pavia (Italy); Maude, D K, E-mail: marioam@fis.ucm.e [Laboratoire National des Champs Magnetiques Intenses, F-38042 Grenoble (France)

    2010-05-15

    We investigate the quantum Hall effect (QHE) in a graphene sample with Hall-bar geometry close to the Dirac point at high magnetic fields up to 28 T. We have discovered a plateau-insulator quantum phase transition passing from the last plateau for the integer QHE in graphene to an insulator regime {nu}=-2{yields}{nu}=0. The analysis of the temperature dependence of the longitudinal resistance gives a value for the critical exponent associated with the transition equal to {kappa}=0.58{+-}0.03.

  6. Improvement of Surface skin temperature simulation over the Tibetan Plateau from an energy balance perspective

    Science.gov (United States)

    Zhuo, Haifeng

    2015-04-01

    There has a big cold bias of temperature about reanalysis and simulations over Tibetan Plateau comparing with observations. In order to solve this problem, for the land -- atmosphere interaction in arid and semi-arid region is mainly dominated by heat transfer process, a latest revision of surface sensible heat parameterization introduced by Zeng et al is then used for bare soil in WRFV3 (CLM4) model. Results show that the annual surface skin temperature has approximately up to 2.0 degree improvement on average over Tibetan Plateau. Firstly, the revised scheme changes the energy balance over and around Tibetan Plateau. It significantly reduces the overestimate of surface sensible heat and improves the surface skin temperature simulation, which tends more close to the observation. Secondly, the revised scheme weakens the sensible heat air pump effect of Tibetan Plateau. The diabatic heating reduce and the updraft airflow weaken especially over the southern slope of plateau, meanwhile the clouds thin, the incident solar radiation increases, eventually led to the increase of surface skin temperature in North India in dry season.

  7. Moho topography of the Tibetan Plateau using multi-scale gravity analysis and its tectonic implications

    Science.gov (United States)

    Xu, Chuang; Liu, Ziwei; Luo, Zhicai; Wu, Yihao; Wang, Haihong

    2017-05-01

    Determining the Moho topography of the Tibetan Plateau is crucial to understand the tectonic development. Over the past decades, seismic explorations have obtained profound results about the Moho topography, except in regions where seismic station coverage is poor, especially in the central and western Tibetan Plateau. In comparison, gravity data have the advantage of global homogeneous coverage, which can thus be used to determine the Moho structure beneath the entire Tibetan Plateau. In this paper, a novel approach, the multi-scale gravity analysis method, is developed to extract the gravity signals originated from the Moho undulations and to determine the Moho topography beneath the whole Tibetan Plateau. The inverted Moho topography for the Tibetan Plateau is consistent with that derived from the previous works. In addition, a rich geophysical structure and tectonic development can be revealed from the inverted Moho topography: (1) The Moho depth in the west is deeper than that in the east, and the deepest Moho, which is approximately 77 km, is located beneath the western Qiangtang Block; (2) There is an obvious Moho offset of approximately 5 km beneath the Yarlung-Zangbo Suture at the juncture between the Himalayan and Lhasa Blocks; (3) The Moho fold and low-density channel flow, the directions of which are in agreement with the results of surface movement velocities estimated from Global Positioning System, can be observed from the Moho topography.

  8. O efeito da fragmentação florestal na composição e riqueza de árvores na região da Reserva Morro Grande (Planalto de Ibiúna, SP. The effect of the forest fragmentation in the composition and richness of trees in the region of the Morro Grande Reserve (Ibiúna plateau, SP.

    Directory of Open Access Journals (Sweden)

    Luís Carlos BERNACCI

    2006-12-01

    the species composition and richnessof sites situated in two landscapes at the IbiúnaPlateau (Cotia and Ibiúna municipalities, SP.Both landscapes are situated in similar abioticconditions, but one is predominantly forested (theMorro Grande Forest Reserve – 9,400 ha, wheresix areas were sampled and the other is anagricultural landscape (where were sampled 21fragments, ranging from 0.9 to 275 ha. We usedthe point-centered-quarter method consideringtrees with diameter equal or wider than 5 cm atbreast height and included a total of 2,400individuals in the Reserve and 5,000 individualsin the fragmented landscape. We observed 362species from 171 genus and 71 families. The richestfamilies were Myrtaceae, Lauraceae, Fabaceae,Rubiaceae and Euphorbiaceae. In the set of thefragments has observed differences in the speciescomposition and smallest richness. In thefragments occurred more abundance and richnessof anemochorous and barochorous and of pioneerand initial secondary species. Inversely, in theMorro Grande Reserve occurred more abundanceand richness of final secondary and umbrophilousand of zoochorous species, detaching the importanceof this area for the maintenance of regionalbiodiversity. Despite these clear fragmentationeffects some threatened species or some speciesthat were never observed in the state of São Paulowere sampled exclusively in the forest fragments,highlighting the importance to preservate thosesmall fragments and to restore the forests in thesouth region of the Atlantic Plateau.

  9. Origin and radiative forcing of black carbon transported to the Himalayas and Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    M. Kopacz

    2011-03-01

    Full Text Available The remote and high elevation regions of central Asia are influenced by black carbon (BC emissions from a variety of locations. BC deposition contributes to melting of glaciers and questions exist, of both scientific and policy interest, as to the origin of the BC reaching the glaciers. We use the adjoint of the GEOS-Chem model to identify the location from which BC arriving at a variety of locations in the Himalayas and Tibetan Plateau originates. We then calculate its direct and snow-albedo radiative forcing. We analyze the seasonal variation in the origin of BC using an adjoint sensitivity analysis, which provides a detailed map of the location of emissions that directly contribute to black carbon concentrations at receptor locations. We find that emissions from northern India and central China contribute the majority of BC to the Himalayas, although the precise location varies with season. The Tibetan Plateau receives most BC from western and central China, as well as from India, Nepal, the Middle East, Pakistan and other countries. The magnitude of contribution from each region varies with season and receptor location. We find that sources as varied as African biomass burning and Middle Eastern fossil fuel combustion can significantly contribute to the BC reaching the Himalayas and Tibetan Plateau. We compute radiative forcing in the snow-covered regions and find the forcing due to the BC induced snow-albedo effect to vary from 5–15 W m−2 within the region, an order of magnitude larger than radiative forcing due to the direct effect, and with significant seasonal variation in the northern Tibetan Plateau. Radiative forcing from reduced snow albedo likely accelerates glacier melting. Our analysis may help inform mitigation efforts to slow the rate of glacial melt by identifying regions that make the largest contributions to BC deposition in the Himalayas and Tibetan Plateau.

  10. Modeling CO2 Sequestration in Saline Aquifer and Depleted Oil Reservoir To Evaluate Regional CO2 Sequestration Potential of Ozark Plateau Aquifer System, South-Central Kansas

    Energy Technology Data Exchange (ETDEWEB)

    Watney, W. Lynn [University Of Kansas Center For Research, Inc. Lawrence, KS (United States); Rush, Jason [University Of Kansas Center For Research, Inc. Lawrence, KS (United States); Raney, Jennifer [University Of Kansas Center For Research, Inc. Lawrence, KS (United States)

    2014-09-30

    1. Drilled, cored, and logged three wells to the basement and collecting more than 2,700 ft of conventional core; obtained 20 mi2 of multicomponent 3D seismic imaging and merged and reprocessed more than 125 mi2 of existing 3D seismic data for use in modeling CO2- EOR oil recovery and CO2 storage in five oil fields in southern Kansas. 2. Determined the technical feasibility of injecting and sequestering CO2 in a set of four depleted oil reservoirs in the Cutter, Pleasant Prairie South, Eubank, and Shuck fields in southwest Kansas; of concurrently recovering oil from those fields; and of quantifying the volumes of CO2 sequestered and oil recovered during the process. 3. Formed a consortium of six oil operating companies, five of which own and operate the four fields. The consortium became part of the Southwest Kansas CO2-EOR Initiative for the purpose of sharing data, knowledge, and interest in understanding the potential for CO2-EOR in Kansas. 4. Built a regional well database covering 30,000 mi2 and containing stratigraphic tops from ~90,000 wells; correlated 30 major stratigraphic horizons; digitized key wells, including wireline logs and sample logs; and analyzed more than 3,000 drill stem tests to establish that fluid levels in deep aquifers below the Permian evaporites are not connected to the surface and therefore pressures are not hydrostatic. Connectivity with the surface aquifers is lacking because shale aquitards and impermeable evaporite layers consist of both halite and anhydrite. 5. Developed extensive web applications and an interactive mapping system that do the following: a. Facilitate access to a wide array of data obtained in the study, including core descriptions and analyses, sample logs, digital (LAS) well logs, seismic data, gravity and magnetics maps, structural and stratigraphic maps, inferred fault traces, earthquakes, Class I and II disposal wells, and

  11. The Hubble Flow of Plateau Inflation

    NARCIS (Netherlands)

    Coone, Dries; Roest, Diederik; Vennin, Vincent

    2015-01-01

    In the absence of CMB precision measurements, a Taylor expansion has often been invoked to parametrize the Hubble flow function during inflation. The standard "horizon flow" procedure implicitly relies on this assumption. However, the recent Planck results indicate a strong preference for plateau

  12. Tectonostratigraphic evolution of Falkland (Malvinas) Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Snavely, P.D. III

    1987-05-01

    The Falkland (a.k.a. Malvinas) Plateau, offshore southern Argentina, came into being as the result of the Late Jurassic-Early Cretaceous breakup of west Gondwanaland and the opening of the South Atlantic. As the trailing edge of the South American plate, this continental salient has periodically interacted with the African, Antarctic, Scotia, and Nazca plates, recording the complex history of Mesozoic and Cenozoic plate reorganization in the Southern Hemisphere. The pelagic depositional setting of the plateau following its separation from Africa has resulted in the accumulation of a relatively thin post-rift sedimentary section. This has allowed not only local penetration of the lower Mesozoic section by borehole but also seismic resolution of the pre- and syn-rift strata beyond that generally obtainable from the thick marine basins of the Argentine or South African continental shelves. These subsurface data have been used to compile a relatively complete depositional and tectonic history for the Falkland Plateau which may be applied, by analogy, to sedimentary basins of similar age along the circum-Gondwana perimeter. Three principal tectonic events appear to have influenced the type and orientation of structures and the distribution of stratal patterns presently observed on the Falkland Plateau. These are (1) a Permo-Triassic compressional event (Cape orogeny) that resulted in the formation of a fold-belt running from northwest Argentina through South Africa and across the Falkland Plateau to Antarctica, (2) the two-stage breakup of the Gondwana supercontinent from Late Triassic to Early Cretaceous time, and (3) the Tertiary opening of the Drake Passage and the formation of the Scotia Sea.

  13. Genetic diversity and sex-bias dispersal of plateau pika in Tibetan plateau.

    Science.gov (United States)

    Zhang, Liangzhi; Qu, Jiapeng; Li, Kexin; Li, Wenjing; Yang, Min; Zhang, Yanming

    2017-10-01

    Dispersal is an important aspect in organism's life history which could influence the rate and outcome of evolution of organism. Plateau pika is the keystone species in community of grasslands in Tibetan Plateau. In this study, we combine genetic and field data to character the population genetic pattern and dispersal dynamics in plateau pika (Ochotona curzoniae). Totally, 1,352 individual samples were collected, and 10 microsatellite loci were analyzed. Results revealed that plateau pika possessed high genetic diversity and inbreeding coefficient in a fine-scale population. Dispersal distance is short and restricted in about 20 m. An effective sex-biased dispersal strategy is employed by plateau pika: males disperse in breeding period for mating while females do it after reproduction for offspring and resource. Inbreeding avoiding was shown as the common driving force of dispersal, together with the other two factors, environment and resource. In addition, natal dispersal is female biased. More detailed genetic analyzes are needed to confirm the role of inbreeding avoidance and resource competition as ultimate cause of dispersal patterns in plateau pika.

  14. Geothermic activity and seismotectonics in the altitude of the Tibetan plateau

    Science.gov (United States)

    Xu, Jiren; Zhao, Zhixin

    2009-12-01

    In the present analysis on the relationships among the depth of lithosphere brittle fracture, seismotectonics and geothermal anomalous active in Tibetan plateau were investigated using the seismic dada from ISC and Chinese seismic net and geothermal data. The results suggest that the region of anomalously geothermal activity almost coincides with that of the normal faulting type earthquake. The geothermal anomaly activity region coincides spatially with that of the events deeper than 60 km as well as. The normal faulting earthquakes may be mainly tectonic activity regimes until 110 km deep in the thermal anomaly region. The strike directions of events are likely the N-S direction, coinciding with the strike of the thermal anomaly active belts. The earthquakes align along the normal faults and faulted-depression zone with the N-S direction. The thermal anomaly activity also distributes along the faulted-depression zone. Many events deeper than 60 km exist in the anomalously geothermal activity region in the plateau. Events extend to bottom of the lithosphere of 110 km from the surface, like columnar seismic crowd. The lithosphere extends along the E-W direction due to the E-W extensional stress in the central and southern Tibetan plateau, altitude of the plateau. The tensional stress in the E-W results in the lithosphere fractures and the normal faults striking N-S direction, grabens and faulted-depression zones. Thermal material from the asthenosphere wells upward to the surface along deep seismic fractures and faults through the thick crust. The anomalously thermal activities are attributable to the upwelling thermal material from the mantle in the altitude of Tibetan plateau.

  15. Holocene moisture evolution across the Mongolian Plateau and its surrounding areas: A synthesis of climatic records

    Science.gov (United States)

    Wang, Wei; Feng, Zhaodong

    Based on the review of 26 high-standard Holocene climatic reconstructions (mainly pollen-based) from the Mongolian Plateau and its surrounding areas, temporal and spatial patterns of the Holocene moisture evolution are synthesized. The regionally-averaged moisture history from the summer monsoon-influenced semiarid belt in China (i.e., Region A) demonstrates that the moisture index curve is broadly in agreement with the synthesized East Asian Monsoon Strength curve, both following the general trend of the West Tropical Pacific SST that is in turn the delayed response to the northern hemispheric summer solar insolation. The regionally-averaged moisture indices from the winter monsoon-dominated southern Siberia including Lake Baikal area and the Altai Mountains (i.e., Region B) exhibit a general declining trends since 10.6-9.6 cal. kyr BP, being largely consistent with the trends of the annual precipitation and the warm-season temperature in the Russian Plain. The consistency might be attributable to the Holocene declining trend of the warm-season temperature in North Atlantic region. The predominant feature of the regionally-averaged moisture index from the westerlies-affected northern Xinjiang (i.e., Region C) is a persistent increasing trend since ~ 8 cal. kyr BP. The wetting trend of northern Xinjiang during the past 8000 years might be attributable to the increasing trend of winter insolation and to the associated increasing trend of cold-season temperature in northwestern Europe. The chronological correspondences between dry phases and warm intervals in the arid areas of the Mongolian Plateau (i.e., northern Mongolian Plateau within Mongolia and southern Mongolian Plateau within China, Region D) lend a support to the proposal that the mid-Holocene dry phase was most likely the result of mid-Holocene high warm-season temperature.

  16. Soil water infiltration impacted by maize (zea mays) growth on sloping agricultural land of the loess plateau

    Science.gov (United States)

    Increasing infiltration rates of sloping agricultural land from arid and semiarid regions not only affects water supply and precipitation transformations in soil directly, but also impacts erosion intensity. This is extremely important to the Loess Plateau regions of Northwest China, where a majorit...

  17. Neogene Patagonian plateau lavas: Continental magmas associated with ridge collision at the Chile Triple Junction

    Science.gov (United States)

    Gorring, Matthew L.; Kay, Suzanne M.; Zeitler, Peter K.; Ramos, Victor A.; Rubiolo, Daniel; Fernandez, Marisa I.; Panza, Jose L.

    1997-02-01

    Extensive Neogene Patagonian plateau lavas (46.5° to 49.5°S) southeast of the modern Chile Triple Junction can be related to opening of asthenospheric "slab windows" associated with collisions of Chile Rise segments with the Chile Trench at ≈ 12 Ma and 6 Ma. Support comes from 26 new total-fusion, whole rock 40Ar/39Ar ages and geochemical data from back arc plateau lavas. In most localities, plateau lava sequences consist of voluminous, tholeiitic main-plateau flows overlain by less voluminous, 2 to 5 million year younger, alkalic postplateau flows. Northeast of where the ridge collided at ≈12 Ma, most lavas are syncollisional or postcollisional in age, with eruptions of both sequences migrating northeastward at 50 to 70 km/Ma. Plateau lavas have ages from 12 to 7 Ma in the western back arc and from 5 to 2 Ma farther to the northeast. Trace element and isotopic data indicate main-plateau lavas formed as larger percentage melts of a garnet-bearing, oceanic island basalt (OIB) -like mantle than postplateau lavas. The highest percentage melts erupted in the western and central plateaus. In a migrating slab window model, main-plateau lavas can be explained as melts that formed as upwelling, subslab asthenosphere which flowed around the trailing edge of the descending Nazca Plate and then interacted with subduction-altered asthenospheric wedge and continental lithosphere. Alkaline, postplateau lavas can be explained as melts generated by weaker upwelling of subslab asthenosphere through the open slab window. Thermal problems of high-pressure melt generation of anhydrous mantle can be explained by volatiles (H2O and CO2) introduced by the subduction process into slab window source region(s). An OIB-like, rather than a mid-ocean ridge basalt (MORB) -like source region, and the lack of magmatism northeast of where ridge collision occurred at ≈13 to 14 Ma can be explained by entrainment of "weak" plume(s) or regional variations in an ambient, OIB-like asthenosphere.

  18. Some practical notes on the land surface modeling in the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    K. Yang

    2009-05-01

    Full Text Available The Tibetan Plateau is a key region of land-atmosphere interactions, as it provides an elevated heat source to the middle-troposphere. The Plateau surfaces are typically characterized by alpine meadows and grasslands in the central and eastern part while by alpine deserts in the western part. This study evaluates performance of three state-of-the-art land surface models (LSMs for the Plateau typical land surfaces. The LSMs of interest are SiB2 (the Simple Biosphere, CoLM (Common Land Model, and Noah. They are run at typical alpine meadow sites in the central Plateau and typical alpine desert sites in the western Plateau.

    The identified key processes and modeling issues are as follows. First, soil stratification is a typical phenomenon beneath the alpine meadows, with dense roots and soil organic matters within the topsoil, and it controls the profile of soil moisture in the central and eastern Plateau; all models, when using default parameters, significantly under-estimate the soil moisture within the topsoil. Second, a soil surface resistance controls the surface evaporation from the alpine deserts but it has not been reasonably modeled in LSMs; an advanced scheme for soil water flow is implemented in a LSM, based on which the soil resistance is determined from soil water content and meteorological conditions. Third, an excess resistance controls sensible heat fluxes from dry bare-soil or sparsely vegetated surfaces, and all LSMs significantly under-predict the ground-air temperature gradient, which would result in higher net radiation, lower soil heat fluxes and thus higher sensible heat fluxes in the models. A parameterization scheme for this resistance has been shown to be effective to remove these biases.

  19. Hydrogeology of the Markagunt Plateau, Southwestern Utah

    Science.gov (United States)

    Spangler, Lawrence E.

    2010-01-01

    The Markagunt Plateau, in southwestern Utah, lies at an altitude of about 9,500 feet and is capped primarily by Quaternary-age basalt that overlies Eocene-age freshwater limestone of the Claron Formation. Over large parts of the Markagunt Plateau, dissolution of the Claron limestone and subsequent collapse of the overlying basalt have produced a terrain characterized by sinkholes as much as 1,000 feet across and 100 feet deep. Numerous large springs discharge from the basalt and underlying limestone on the plateau, including Mammoth Spring, one of the largest springs in Utah, with a discharge that can exceed 300 cubic feet per second. Discharge from Mammoth Spring is from the Claron Formation; however, recharge to the spring largely takes place by both focused and diffuse infiltration through the basalt that caps the limestone. Results of dye tracing to Mammoth Spring indicate that recharge originates largely southwest of the spring outside of the Mammoth Creek watershed, as well as from losing reaches along Mammoth Creek. Maximum groundwater travel time to the spring from dye-tracer tests during the snowmelt runoff period was about 1 week. Specific conductance and water temperature data from the spring show an inverse relation to discharge during snowmelt runoff and rainfall events, also indicating short groundwater residence times. Results of major-ion analyses for samples collected from Mammoth and other springs on the plateau indicate calcium-bicarbonate type water containing low (less than 200 mg/L) dissolved-solids concentrations. Investigations in the Navajo Lake area along the southern margin of the plateau have shown that water losing to sinkholes bifurcates and discharges to both Cascade and Duck Creek Springs, which subsequently flow into the Virgin and Sevier River basins, respectively. Groundwater travel times to these springs, on the basis of dye tracing, were about 8.5 and 53 hours, respectively. Similarly, groundwater travel time from Duck Creek

  20. PLATEAUING COSMIC RAY DETECTORS TO ACHIEVE OPTIMUM OPERATING VOLTAGE

    Energy Technology Data Exchange (ETDEWEB)

    Knoff, E.N.; Peterson, R.S.

    2008-01-01

    Through QuarkNet, students across the country have access to cosmic ray detectors in their high school classrooms. These detectors operate using a scintillator material and a photomultiplier tube (PMT). A data acquisition (DAQ) board counts cosmic ray hits from the counters. Through an online e-Lab, students can analyze and share their data. In order to collect viable data, the PMTs should operate at their plateau voltages. In these plateau ranges, the number of counts per minute remains relatively constant with small changes in PMT voltage. We sought to plateau the counters in the test array and to clarify the plateauing procedure itself. In order to most effectively plateau the counters, the counters should be stacked and programmed to record the number of coincident hits as well as their singles rates. We also changed the threshold value that a signal must exceed in order to record a hit and replateaued the counters. For counter 1, counter 2, and counter 3, we found plateau voltages around 1V. The singles rate plateau was very small, while the coincidence plateau was very long. The plateau voltages corresponded to a singles rate of 700–850 counts per minute. We found very little effect of changing the threshold voltages. Our chosen plateau voltages produced good performance studies on the e-Lab. Keeping in mind the nature of the experiments conducted by the high school students, we recommend a streamlined plateauing process. Because changing the threshold did not drastically affect the plateau voltage or the performance study, students should choose a threshold value, construct plateau graphs, and analyze their data using a performance study. Even if the counters operate slightly off their plateau voltage, they should deliver good performance studies and return reliable results.

  1. A new map of permafrost distribution on the Tibetan Plateau

    Science.gov (United States)

    Zou, Defu; Zhao, Lin; Sheng, Yu; Chen, Ji; Hu, Guojie; Wu, Tonghua; Wu, Jichun; Xie, Changwei; Wu, Xiaodong; Pang, Qiangqiang; Wang, Wu; Du, Erji; Li, Wangping; Liu, Guangyue; Li, Jing; Qin, Yanhui; Qiao, Yongping; Wang, Zhiwei; Shi, Jianzong; Cheng, Guodong

    2017-11-01

    The Tibetan Plateau (TP) has the largest areas of permafrost terrain in the mid- and low-latitude regions of the world. Some permafrost distribution maps have been compiled but, due to limited data sources, ambiguous criteria, inadequate validation, and deficiency of high-quality spatial data sets, there is high uncertainty in the mapping of the permafrost distribution on the TP. We generated a new permafrost map based on freezing and thawing indices from modified Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperatures (LSTs) and validated this map using various ground-based data sets. The soil thermal properties of five soil types across the TP were estimated according to an empirical equation and soil properties (moisture content and bulk density). The temperature at the top of permafrost (TTOP) model was applied to simulate the permafrost distribution. Permafrost, seasonally frozen ground, and unfrozen ground covered areas of 1.06 × 106 km2 (0.97-1.15 × 106 km2, 90 % confidence interval) (40 %), 1.46 × 106 (56 %), and 0.03 × 106 km2 (1 %), respectively, excluding glaciers and lakes. Ground-based observations of the permafrost distribution across the five investigated regions (IRs, located in the transition zones of the permafrost and seasonally frozen ground) and three highway transects (across the entire permafrost regions from north to south) were used to validate the model. Validation results showed that the kappa coefficient varied from 0.38 to 0.78 with a mean of 0.57 for the five IRs and 0.62 to 0.74 with a mean of 0.68 within the three transects. Compared with earlier studies, the TTOP modelling results show greater accuracy. The results provide more detailed information on the permafrost distribution and basic data for use in future research on the Tibetan Plateau permafrost.

  2. Quantifying landscape differences across the Tibetan plateau: Implications for topographic relief evolution

    Science.gov (United States)

    Liu-Zeng, J.; Tapponnier, P.; Gaudemer, Y.; Ding, L.

    2008-12-01

    We quantify the bulk topographic characteristics of the Tibet-Qinghai plateau with specific focus on three representative regions: northern, central, and southeastern Tibet. Quantitative landscape information is extracted from Shuttle Radar Topography Mission digital elevation models. We find that the morphology of the Tibetan plateau is nonuniform with systematic regional differences. The northern and central parts of the plateau are characterized by what we suggest to call "positive topography," i.e., a topography in which elevation is positively correlated with relief and mean slope. A major change from the internally drained central part of Tibet to the externally drained part of eastern Tibet is accompanied by a transition from low to high relief and from positive to "negative topography," i.e., a topography where there is an inverse or negative correlation between elevation and relief and between elevation and mean slope. Relief in eastern Tibet is largest along rivers as they cross an ancient, eroded plateau margin at high angle to the major strike-slip faults, the Yalong-Yulong thrust belt, implying strong structural control of regional topography. We propose that the evolution of river systems and drainage efficiency, the ability of rivers to transport sediments out of the orogen, coupled with tectonic uplift, is the simplest mechanism to explain systematic regional differences in Tibetan landscapes. Basin filling due to inefficient drainage played a major role in smoothing out the tectonically generated structural relief. This mode of smoothing started concurrently with tectonic construction of the relief, as most clearly illustrated today in the Qilian Shan-Qaidam region of the northeastern plateau. In the interior of Tibet, further "passive" filling, due to internal drainage only, continued to smooth the local relief millions of years after the cessation of major phases of surface uplift due to crustal shortening. Thus, diachronous beveling at high

  3. Climate processes on the antarctic plateau

    Energy Technology Data Exchange (ETDEWEB)

    Warren, S.G.; Harder, S.L.; Brandt, R.E. (Univ. of Washington, Seattle, WA (United States))

    1993-12-01

    Experiments on the climate processes on the antarctic plateau, begun at the South Pole in the 1990-91 summer season and carried out during the full year December 1991 to December 1992 are summarized in the article. Experiments discussed include the following: Effect of sastrugi on bidirectional reflectance of snow; temperatures in the near-surface snow; atmospheric longwave radiation spectrum; Air snow exchange processes; sampling of falling and surface snow; air sampling; blowing and drifting snow. 8 refs.

  4. The Influence of Arctic Oscillation and ENSO on Snow Cover Days on Qinghai-Tibetan Plateau

    Science.gov (United States)

    Xiao, Tiangui; Wang, Chao; Jia, Lha; Du, Jun; Chen, Qianwen

    2017-04-01

    Based on Qinghai-Tibetan Plateau Snow data, index of NINO sea temperature anomaly, and AO index. The influence from Arctic Oscillation and ENSO to days of snow cover in plateau was studied, and the main conclusions are as follows: 1. Both AO index and NINO index are positively correlated with days of snow cover in plateau, and the correlation coefficients are 0.59, 0.41 respectively (both passed the significant test at0.01 level). There is a positively correlation between NINO index and western plateau, and passed the significant test. But to the eastern plateau, it is uncorrelated. 2. The average of snow cover days in whole plateau is 8.79 d, during 1964-2013. The maximum value of snow cover days is 41.38 d in Nielamu, and the minimum lesser than 1 d in Haiyan. When the AO at positive anomaly, the snow cover days is higher, and the maximum value up to 48.8d at Jiani. At in negative anomaly of AO, the snow cover day is lower. There is a positively correlation between AO and snow cover days. 3. When the AO at positive anomaly with El Nino, the maximum value of snow cover days up to 54.25 d. Influence of AO and El Nino, the snow cover days is higher. When the AO at positive anomaly with La Nina, the maximum value of snow cover days is 46.3 d, and it is lower than the maximum value which is under AO at positive anomaly period. When the AO at negative anomaly whit El Nino, the value range of snow cover days is 0.007-42.86 d. Due to the Influence of El Nino, the value snow cover days is higher, but with smaller region. When the AO at negative anomaly whit La Nina, the snow cover days is lower in whole plateau. the snow cover days was directly affected by AO and ENSO, and the first is more effective than the latter. Key words: AO; ENSO; Qinghai-Tibetan Plateau; snow cover days Acknowledgements This study was supported by National Natural Science Foundation of China Fund Project (91337215, 41575066), National Key Basic Research Program (2013CB733206), Special Fund for

  5. Toward Quantitative Understanding of the Atmospheric Heating over the Tibetan Plateau (Invited)

    Science.gov (United States)

    Koike, T.; Tamura, T.; Rasmy, M.; Seto, R.

    2010-12-01

    contradictory to the Taniguchi and Koike [2007]. The mechanism of the upper tropospheric warming is investigated using the climatology derived from the reanalysis data. Heat budget analysis of the upper troposphere revealed adiabatic subsidence plays an important role for the temperature increase from late April to mid-June. The adiabatic heating is suggested to be derived from the southerly and westerly component of the upper tropospheric circulation. Tamura, Taniguchi and Koike [2009]. To get more quantitative understanding of the atmospheric heating over the Tibetan Plateau, a satellite-based land data assimilation system coupled with a regional atmospheric model was developed.. The result of the system validation for the land surface fluxes and atmospheric parameters shows better consistency with the observed data. The role of land surface on the atmospheric heating can be quantitatively analyzed.

  6. The shape of soap films and Plateau borders

    Energy Technology Data Exchange (ETDEWEB)

    Fortes, M A [Departamento de Engenharia de Materiais and Instituto de Ciencia e Engenharia de Materiais e SuperfIcies, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisbon (Portugal); Teixeira, P I C [Instituto Superior de Engenharia de Lisboa Rua Conselheiro EmIdio Navarro 1, P-1950-062 Lisbon (Portugal); Deus, A M [Departamento de Engenharia de Materiais and Instituto de Ciencia e Engenharia de Materiais e SuperfIcies, Instituto Superior Tecnico, Avenida Rovisco Pais, P-1049-001 Lisbon (Portugal)

    2007-06-20

    We have calculated the shapes of flat liquid films, and of the transition region to the associated Plateau borders (PBs), by integrating the Laplace equation with a position-dependent surface tension {gamma}(x), where 2x is the local film thickness. We discuss films in either zero or non-zero gravity, using standard {gamma}(x) potentials for the interaction between the two bounding surfaces. We have investigated the effects of the film flatness, liquid underpressure, and gravity on the shape of films and their PBs. Films may exhibit 'humps' and/or 'dips' associated with inflection points and minima of the film thickness. Finally, we propose an asymptotic analytical solution for the film width profile.

  7. The shape of soap films and Plateau borders.

    Science.gov (United States)

    Fortes, M A; Teixeira, P I C; Deus, A M

    2007-06-20

    We have calculated the shapes of flat liquid films, and of the transition region to the associated Plateau borders (PBs), by integrating the Laplace equation with a position-dependent surface tension γ(x), where 2x is the local film thickness. We discuss films in either zero or non-zero gravity, using standard γ(x) potentials for the interaction between the two bounding surfaces. We have investigated the effects of the film flatness, liquid underpressure, and gravity on the shape of films and their PBs. Films may exhibit 'humps' and/or 'dips' associated with inflection points and minima of the film thickness. Finally, we propose an asymptotic analytical solution for the film width profile.

  8. Middle Pleistocene infill of Tibetan Plateau margin rivers, Zanskar, India

    Science.gov (United States)

    Munack, Henry; Blöthe, Jan; Korup, Oliver; Fülöp, Réka-Hajnalka; Codilean, Alexandru T.; Fink, David

    2015-04-01

    The Indus, one of Asia's premier rivers, drains the NW Himalaya and the Transhimalayan ranges that fringe the western Tibetan Plateau margin. There, upstream of the western Himalayan syntaxis, river valleys alternate between deeply incised bedrock gorges and broad alluviated reaches, while average denudation rates decrease by an order of magnitude towards the Tibetan Plateau margin to rates of ~10 mm ka-1. Vast fill terrace staircases, the highest of them located up to 400 m above current river level, and intercalated lake sediments indicate alternating phases of incision and aggradation within the region, underlining the high landform preservation potential in the rain shadow of the High Himalaya. However, despite a broad interest in a better understanding of mechanisms that modulate plateau erosion, age constraints on the generation of these impressive features are sparse, though indicate mainly Pleistocene formation ages. We present new age constraints from the More Plains section in the headwaters of the Zanskar River, a major tributary to the upper Indus. The vast sedimentary successions of the More Plains originally belonged to a former endorheic basin that has been tapped by the Zanskar River, today revealing exposures of >250 m of sedimentary fill that continues to smother a previously dissected alpine headwater landscape. We combine 10Be surface exposure dating and catchment-averaged denudation rates, morphometric analysis and field observation to constrain the late Quaternary history of this section. Analysis of a 10Be depth profile on top of the More Plains, together with the dating of nearby amalgamated surface samples, indicate a surface exposure of ~170 +/- 20 ka such that deposition of this valley fill ceased during a Middle Pleistocene cold stage (MIS 6). Using GIS-based algorithms we estimate that ~3.6 km3 was removed from this section by fluvial erosion, requiring a specific sediment yield of >130 t km-2 yr-1 averaged over the past 170 ka. This

  9. Pv rural electrification programme at the Bolivian high plateau

    Energy Technology Data Exchange (ETDEWEB)

    Lorenzo, E.; Aguilera, J. [Instituto de Energia Solar, ETSI Telecomunicacion, (Spain)

    1995-12-31

    Since 1988 the Institute of Solar Energy of the Universidad Politecnica de Madrid is carrying out a pv rural electrification programme at the Bolivian high plateau. This programme has been focused in three aspects: the domestic electrification, users participation and transfer technology. At present, there are about 1,500 electrified dwellings distributed in the Bolivian high plateau. We have got deep knowledge about life style and organization of the aymara Indians who are the inhabitants of the working zone. We think that this knowledge can be very useful for a large scale introduction of PV solar energy in this region. Finally, we present a new way to transfer PV technology to developing countries. Thanks to this programme a group of aymara Indians is able to manufacture charge regulators and electronic ballast to use in the PV installations of the programme. [Espanol] Desde 1988 el Instituto de Energia Solar de la Universidad Politecnica de Madrid esta llevando a cabo un programa fotovoltaico de electrificacion rural en la altiplanicie Boliviana. Este programa ha sido enfocado a tres aspectos: la electrificacion domestica, la participacion de los usuarios y la transferencia de la tecnologia. Actualmente, hay alrededor de 1500 conjuntos habitacionales electrificados distribuidos en la altiplanicie Boliviana. Hemos obtenido un profundo conocimiento del estilo de vida y de la organizacion de los indios aymara que son los habitantes de la zona de trabajo. Pensamos que este conocimiento puede ser muy util para una introduccion en gran escala de la energia solar fotovoltaica en esta region. Finalmente, presentamos una nueva forma de transferir la tecnologia fotovoltaica a paises en desarrollo. Gracias a este programa un grupo de indios aymara pueden fabricar reguladores de carga y balastros electronicos para ser usados en instalaciones fotovoltaicas del programa.

  10. Mapping of lithologic and structural units using multispectral imagery. [Afar-Triangle/Ethiopia and adjacent areas (Ethiopian Plateau, Somali Plateau, and parts of Yemen and Saudi Arabia)

    Science.gov (United States)

    Kronberg, P. (Principal Investigator)

    1974-01-01

    The author has identified the following significant results. ERTS-1 MSS imagery covering the Afar-Triangle/Ethiopia and adjacent regions (Ethiopian Plateau, Somali Plateau, and parts of Yemen and Saudi Arabi) was applied to the mapping of lithologic and structural units of the test area at a scale 1:1,000,000. Results of the geological evaluation of the ERTS-1 imagery of the Afar have proven the usefullness of this type of satellite data for regional geological mapping. Evaluation of the ERTS images also resulted in new aspects of the structural setting and tectonic development of the Afar-Triangle, where three large rift systems, the oceanic rifts of the Red Sea and Gulf of Aden and the continental East African rift system, seem to meet each other. Surface structures mapped by ERTS do not indicate that the oceanic rift of the Gulf of Aden (Sheba Ridge) continues into the area of continental crust west of the Gulf of Tadjura. ERTS data show that the Wonji fault belt of the African rift system does not enter or cut through the central Afar. The Aysha-Horst is not a Horst but an autochthonous spur of the Somali Plateau.

  11. New insights into trace elements deposition in the snow packs at remote alpine glaciers in the northern Tibetan Plateau, China.

    Science.gov (United States)

    Dong, Zhiwen; Kang, Shichang; Qin, Xiang; Li, Xiaofei; Qin, Dahe; Ren, Jiawen

    2015-10-01

    Trace element pollution resulting from anthropogenic emissions is evident throughout most of the atmosphere and has the potential to create environmental and health risks. In this study we investigated trace element deposition in the snowpacks at two different locations in the northern Tibetan Plateau, including the Laohugou (LHG) and the Tanggula (TGL) glacier basins, and its related atmospheric pollution information in these glacier areas, mainly focusing on 18 trace elements (Li, Be, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Nb, Mo, Cd, Sb, Cs, Ba, Tl, and Pb). The results clearly demonstrate that pronounced increases of both concentrations and crustal enrichment factors (EFs) are observed in the snowpack at the TGL glacier basin compared to that of the LHG glacier basin, with the highest EFs for Sb and Zn in the TGL basin, whereas with the highest EFs for Sb and Cd in the LHG basin. Compared with other studies in the Tibetan Plateau and surrounding regions, trace element concentration showed gradually decreasing trend from Himalayan regions (southern Tibetan Plateau) to the TGL basin (central Tibetan Plateau), and to the LHG basin (northern Tibetan Plateau), which probably implied the significant influence of atmospheric trace element transport from south Asia to the central Tibetan Plateau. Moreover, EF calculations at two sites showed that most of the heavy metals (e.g., Cu, Zn, Mo, Cd, Sb, and Pb) were from anthropogenic sources and some other elements (e.g., Li, Rb, and Ba) were mainly originated from crustal sources. MODIS atmospheric optical depth (AOD) fields derived using the Deep Blue algorithm and CALIOP/CALIPSO transect showed significant influence of atmospheric pollutant transport from south Asia to the Tibetan Plateau, which probably caused the increased concentrations and EFs of trace element deposition in the snowpack on the TGL glacier basin. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Magnetization Process of the Spin-1/2 Triangular-Lattice Heisenberg Antiferromagnet with Next-Nearest-Neighbor Interactions — Plateau or Nonplateau —

    Science.gov (United States)

    Nakano, Hiroki; Sakai, Tôru

    2017-11-01

    An S = 1/2 triangular-lattice Heisenberg antiferromagnet with next-nearest-neighbor (NNN) interactions is investigated under a magnetic field by the numerical-diagonalization method. It is known that, in both cases of weak and strong NNN interactions, this system reveals a magnetization plateau at one-third of the saturated magnetization. We examine the stability of this magnetization plateau when the amplitude of NNN interactions is varied. We find that a nonplateau region appears between the plateau phases in the cases of weak and strong NNN interactions.

  13. Palaeogene growth of the northeastern Tibetan Plateau: Detrital fission track and sedimentary analysis of the Lanzhou basin, NW China

    Science.gov (United States)

    Wang, Xiuxi; Deng, Lizheng; Zattin, Massimiliano; Ji, Minxiao; Li, Jijun

    2017-10-01

    The Palaeogene evolution of the northeastern Tibetan Plateau remains elusive, because of the paucity of well-dated long-lasting and continuous sedimentary records. In this work, we present a detailed detrital apatite fission track thermochronology and stratigraphic study in the Lanzhou basin, located on the eastern-most margin of northeastern Tibet, where Eocene to middle Miocene sediments are well preserved. Combining the analysis of sedimentology records and synsedimentary tectonic structures, four regional tectonic phases are deciphered (52-47 Ma, 40-32 Ma, 23-20 Ma and modern northeastern portion of the Tibetan Plateau has been buildup since then. Thereafter, the growth of the northeastern Tibetan Plateau was dominated by a tectonic activity/inactivity cycle until late Miocene. Thus, the regional growth history appears to have been episodic in nature during the Cenozoic.

  14. Insights into the crustal structure and magmatic evolution of the High and Western Plateau of the Manihiki Plateau, Central Pacific

    Science.gov (United States)

    Hochmuth, Katharina; Gohl, Karsten; Uenzelmann-Neben, Gabriele

    2014-05-01

    The Manihiki Plateau is a Large Igneous Province (LIP) located in the Central Pacific. It is assumed, that the formation of the Manihiki Plateau took place during the early Cretaceous in multiple volcanic stages as part of the "Super-LIP" Ontong-Java-Nui. The plateau consists of several sub-plateaus of which the Western Plateau und High Plateau are the largest. In addressing the plateau's magmatic evolutionary history, one of the key questions is whether all sub-plateaus experienced the same magmatic history or if distinct phases of igneous or tectonic processes led to its fragmentation. During the RV Sonne cruise SO-224 in 2012; we collected two deep crustal seismic refraction/wide-angle reflection lines, crossing the two main sub-plateaus. Modeling of P- and S-wave phases reveals the different crustal nature of both sub-plateaus. On the High Plateau, the 20 km thick crust is divided into four seismic units, interpreted to range from basaltic composition in the uppermost crust to peridotitic composition in the middle and lower crust. The Western Plateau on the other hand shows multiple rift structures and no indications of basalt flows. With a maximum of 17 km crustal thickness, the Western Plateau is also thinner than the High Plateau. The upper basement layers show relatively low P-wave velocities (3.0 - 5.0 km/s), which infers that on the Western Plateau these layers consist of volcanoclastic and carbonatic rocks rather than basaltic flow units. Later volcanic stages may be restricted to the High Plateau with a possible eastward trend in the center of volcanic activity. Extensive secondary volcanism does not seem to have occurred on the Western Plateau, and its later deformation is mainly caused by tectonic extension and rifting.

  15. Estimates of grassland biomass and turnover time on the Tibetan Plateau

    Science.gov (United States)

    Xia, Jiangzhou; Ma, Minna; Liang, Tiangang; Wu, Chaoyang; Yang, Yuanhe; Zhang, Li; Zhang, Yangjian; Yuan, Wenping

    2018-01-01

    The grassland of the Tibetan Plateau forms a globally significant biome, which represents 6% of the world’s grasslands and 44% of China’s grasslands. However, large uncertainties remain concerning the vegetation carbon storage and turnover time in this biome. In this study, we quantified the pool size of both the aboveground and belowground biomass and turnover time of belowground biomass across the Tibetan Plateau by combining systematic measurements taken from a substantial number of surveys (i.e. 1689 sites for aboveground biomass, 174 sites for belowground biomass) with a machine learning technique (i.e. random forest, RF). Our study demonstrated that the RF model is effective tool for upscaling local biomass observations to the regional scale, and for producing continuous biomass estimates of the Tibetan Plateau. On average, the models estimated 46.57 Tg (1 Tg = 1012g) C of aboveground biomass and 363.71 Tg C of belowground biomass in the Tibetan grasslands covering an area of 1.32 × 106 km2. The turnover time of belowground biomass demonstrated large spatial heterogeneity, with a median turnover time of 4.25 years. Our results also demonstrated large differences in the biomass simulations among the major ecosystem models used for the Tibetan Plateau, largely because of inadequate model parameterization and validation. This study provides a spatially continuous measure of vegetation carbon storage and turnover time, and provides useful information for advancing ecosystem models and improving their performance.

  16. Vegetation Restoration, Soil Erosion and Sediment Yield on the Loess Plateau After "GFG" Project

    Science.gov (United States)

    Jiao, Juying

    2017-04-01

    Soil erosion is an increasing environmental problem globally, and the Chinese Loess Plateau suffers the most severe soil erosion in the world. To control soil and water losses and improve ecosystem of the Loess Plateau, significant efforts have been made since the 1950s, especially the implementation of "Grain for Green (GFG)" policy in 1999 on a large scale. After about 15 years of "GFG" implementation, vegetation restored evidently, and soil erosion and sediment yield reduced markedly on the Loess Plateau region. However, for the lager-scale afforestation on the Loess Plateau, the relationship between afforestation and soil water carrying capacity, the sustainability of afforestation and ecosystem should be considered. Although the comprehensive practices have achieved remarkable soil erosion control, soil erosion is still likely to be very severe during heavy rainstorms, especially in gully slope. Attention should be paid in strengthening the storage and drainage measures in the inter-gully to prevent gravitational erosion by reducing the slope runoff flowing down the gully. Proper and rational control measures and management methods in different sections must be investigated further and focused on preventing soil erosion at the sources rather than intercepting sediment with potential risk to the watershed.

  17. Geologic field-trip guide to the volcanic and hydrothermal landscape of the Yellowstone Plateau

    Science.gov (United States)

    Morgan Morzel, Lisa Ann; Shanks, W. C. Pat; Lowenstern, Jacob B.; Farrell, Jamie M.; Robinson, Joel E.

    2017-11-20

    Yellowstone National Park, a nearly 9,000 km2 (~3,468 mi2) area, was preserved in 1872 as the world’s first national park for its unique, extraordinary, and magnificent natural features. Rimmed by a crescent of older mountainous terrain, Yellowstone National Park has at its core the Quaternary Yellowstone Plateau, an undulating landscape shaped by forces of late Cenozoic explosive and effusive volcanism, on-going tectonism, glaciation, and hydrothermal activity. The Yellowstone Caldera is the centerpiece of the Yellowstone Plateau. The Yellowstone Plateau lies at the most northeastern front of the 17-Ma Yellowstone hot spot track, one of the few places on Earth where time-transgressive processes on continental crust can be observed in the volcanic and tectonic (faulting and uplift) record at the rate and direction predicted by plate motion. Over six days, this field trip presents an intensive overview into volcanism, tectonism, and hydrothermal activity on the Yellowstone Plateau (fig. 1). Field stops are linked directly to conceptual models related to monitoring of the various volcanic, geochemical, hydrothermal, and tectonic aspects of the greater Yellowstone system. Recent interest in young and possible future volcanism at Yellowstone as well as new discoveries and synthesis of previous studies, (for example, tomographic, deformation, gas, aeromagnetic, bathymetric, and seismic surveys), provide a framework in which to discuss volcanic, hydrothermal, and seismic activity in this dynamic region.

  18. Assessing Orographic Variability in Glacial Thickness Changes at the Tibetan Plateau Using ICESat Laser Altimetry

    Directory of Open Access Journals (Sweden)

    Vu Hien Phan

    2017-02-01

    Full Text Available Monitoring glacier changes is essential for estimating the water mass balance of the Tibetan Plateau. In this study, we exploit ICESat laser altimetry data in combination with the SRTM DEM and the GLIMS glacier mask to estimate trends in change in glacial thickness between 2003 and 2009 on the whole Tibetan Plateau. Considering acquisition conditions of ICESat measurements and terrain surface characteristics, annual glacier elevation trends were estimated for 15 different settings with respect to terrain slope and roughness. In the end, we only included ICESat elevations acquired over terrain with a slope below 20° and a roughness at the footprint scale below 15 m. With this setting, 90 glaciated areas could be distinguished. The results show that most of observed glaciated areas on the Tibetan Plateau are thinning, except for some glaciers in the northwest. In general, glacier elevations on the whole Tibetan Plateau decreased at an average rate of -0.17±  0.47 m per year (m a-1 between 2003 and 2009, taking together glaciers of any size, distribution, and location of the observed glaciated area. Both rate and rate error estimates are obtained by accumulating results from individual regions using least squares techniques. Our results notably show that trends in glacier thickness change indeed strongly depend on the relative position in a mountain range.

  19. Seismic imaging of a mid-lithospheric discontinuity beneath Ontong Java Plateau

    Science.gov (United States)

    Tharimena, Saikiran; Rychert, Catherine A.; Harmon, Nicholas

    2016-09-01

    Ontong Java Plateau (OJP) is a huge, completely submerged volcanic edifice that is hypothesized to have formed during large plume melting events ∼90 and 120 My ago. It is currently resisting subduction into the North Solomon trench. The size and buoyancy of the plateau along with its history of plume melting and current interaction with a subduction zone are all similar to the characteristics and hypothesized mechanisms of continent formation. However, the plateau is remote, and enigmatic, and its proto-continent potential is debated. We use SS precursors to image seismic discontinuity structure beneath Ontong Java Plateau. We image a velocity increase with depth at 28 ± 4 km consistent with the Moho. In addition, we image velocity decreases at 80 ± 5 km and 282 ± 7 km depth. Discontinuities at 60-100 km depth are frequently observed both beneath the oceans and the continents. However, the discontinuity at 282 km is anomalous in comparison to surrounding oceanic regions; in the context of previous results it may suggest a thick viscous root beneath OJP. If such a root exists, then the discontinuity at 80 km bears some similarity to the mid-lithospheric discontinuities (MLDs) observed beneath continents. One possibility is that plume melting events, similar to that which formed OJP, may cause discontinuities in the MLD depth range. Plume-plate interaction could be a mechanism for MLD formation in some continents in the Archean prior to the onset of subduction.

  20. Chemical erosion and hydrologic budget for the Susure karst plateau

    Directory of Open Access Journals (Sweden)

    Nikić Zoran

    2010-01-01

    Full Text Available The karst plateau of Susure, about 4.5 km2 in surface area, is situated on the Jadovnik eastern offset, western Serbia. The plateau is a morphologic unit higher 15 m to 30 m than the surrounding terrain. The unit consists of crushed and karstified Middle Triassic limestones. Numerous hydrogeological and geomorphologic features of the plateau are attractive for visitors in this economically underdeveloped country. Rocks building up the surrounding terrain are largely peridotites. Surface streams flow neither into nor off the plateau. Atmospheric precipitations discharge to evapotanspiration and filtration underground. More than eighteen constant springs at the limestone/peridotite tectonic contact drain fracture aquifers on the karst plateau border. Measured precipitations and springflows were the input and output data for accounting water budget of an aquifer of Middle Triassic limestones in the Susure plateau.

  1. The Characters of Dry Soil Layer on the Loess Plateau in China and Their Influencing Factors

    Science.gov (United States)

    Yan, Weiming; Deng, Lei; Zhong, Yangquanwei; Shangguan, Zhouping

    2015-01-01

    A dry soil layer (DSL) is a common soil desiccation phenomenon that generally forms at a particular depth in the soil profile because of climatic factors and poor land management, and this phenomenon can influence the water cycle and has been observed on the Loess Plateau of China and other similar regions around the world. Therefore, an investigation of the DSL formation depth (DSLFD), thickness (DSLT) and mean water content (MWDSL) on the Loess Plateau can provide valuable information. This paper synthesized 69 recent publications (1,149 observations of DSLs from 73 sites) that focused on DSLs in this region, and the results indicated that DSLs are significantly affected by climatic and vegetation factors. The mean annual precipitation had a significant positive relationship with DSLFD (p = 0.0003) and MWDSL (paffecting DSLs will provide information for use in guidelines for the sustainable development of economies and restoration of natural environments experiencing water deficiencies. PMID:26241046

  2. CASE-IPY: autonomous seismic stations newly deployed on the East Antarctic Plateau

    Science.gov (United States)

    Leveque, Jean-Jacques; Maggi, Alessia; Souriau, Annie; Wittlinger, Gerard

    2010-05-01

    The Concordia Seismic Experiment CASE-IPY, set up for the International Polar Year, aims at deploying 5 to 8 autonomous seismic stations on the East Antarctic Plateau between Concordia (Dome C) and Vostok. It is part of the international POLENET initiative, and is coordinated with the GAMSEIS (USA-China-Japan) deployment in the region of Gamburtsev mountains. The general purpose of these projects is both to dramatically improve the coverage of the plateau to get a better knowledge of the underlying crustal and lithospheric structures, and to record waves travelling through the inner core along polar paths, that are rare, though critical for core studies. After a phase of preliminary tests, and delays due to logistical possibilities in the region, several stations have been deployed in January 2010. We will present the first results obtained from signal recorded up to now on these stations and from other signals recorded similarly on seismometers lying over several kilometers of ice.

  3. Hydrogeology - MO 2014 Thermoclines Springfield Plateau Aquifer (SHP)

    Data.gov (United States)

    NSGIC State | GIS Inventory — Springfield Plateau aquifer thermo cline correlates the temperature data throughout the state in the upper Mississippian Subsystem, from the Ste. Genevieve Limestone...

  4. Species interactions slow warming-induced upward shifts of treelines on the Tibetan Plateau

    OpenAIRE

    Liang, Eryuan

    2016-01-01

    The alpine treeline is commonly regarded as being sensitive to climatic warming because regeneration and growth of trees at treeline generally are limited by low temperature. The alpine treelines of the Tibetan Plateau (TP) occur at the highest elevations (4,900 m above sea level) in the Northern Hemisphere. Ongoing climatic warming is expected to shift treelines upward. Studies of treeline dynamics at regional and local scales, however, have yielded conflicting results, indicating either unc...

  5. Recent aeolian erosion and deposition in the north polar plateau of Mars.

    OpenAIRE

    Bourke, Mary

    2007-01-01

    PUBLISHED Background: Planum Boreum, the north polar plateau of Mars, displays four extensive low-albedo regions covered with widespread se dimentary deposits that are thick enough to partly or completely suppress the signature of the residual water ice that forms the uppermost zone of the polar layered deposits. These sedi mentary deposits appear to have a source primarily in a buried sedimentary layer preferentially exposed along the wall s and floors of som...

  6. Therapeutical Management of the Tibial Plateau Fractures

    Directory of Open Access Journals (Sweden)

    Obada B.

    2016-11-01

    Full Text Available The study was aimed to identify the role of surgical treatment of tibial plateau fractures, its functional outcome and complications. Demographic data for the patients and details of current clinical and radiological follow-up findings were obtained to assess range of motion, clinical stability, alignment of the knee, and posttraumatic arthrosis (Kellgren/Lawrence score. 64 cases of tibial plateau fractures treated by different surgical methods and variuos implants type were studied from 2013 to 2015 and followed-up for minimum period of 6 months. The systematisation of the casuitry was made using Schatzker and AO classifications. The treatment methods consist of: percutaneous cannulated cancellous screws, ORIF with buttress plate with or without bone grafting, locking or nonlocking plates, external fixator. As complications we found: redepression 4 case, malunion 2 cases, knee stiffness 9, wound dehiscence in 1 cases and non-union or infection in none of our cases. The average flexion of the injured knee was significantly lower in comparison with the contralateral side (124.9°/135.2°. Knee stability did not differ statistically significantly. There were no signs of posttraumatic arthrosis in 45% of cases, mild signs in 30%, clear signs in 18%, and severe signs in 7%. As conclusion we found that surgical management of tibial plateau fractures will give excellent anatomical reduction and rigid fixation to restore articular congruity, facilitate early motion and reduce arthrosis risk and hence to achieve optimal knee function. The choice of optimal surgical methods, proper approach and implant is made in relation to fracture type according Schatzker and AO classification.

  7. Operative results of closed tibial plateau fractures

    Directory of Open Access Journals (Sweden)

    Mathur Hitin

    2005-01-01

    Full Text Available Background: Management of tibial plateau fractures remains challenging because of their number, variety and associated soft tissue injuries that further augment their complexity. Comparison of operative results in recent reports has been difficult due to a lack of standard fracture classification scheme and uniform standardized objective criteria for evaluating results. Methods: Between August 1998 to December 2002, 27 closed tibial plateau fractures were treated operatively using methods and principles advocated by AO/ASIF and followed up for an average of 35.74 months (range 24-68 months. Fractures were classified according to Schatzker′s staging system and results evaluated using Rasmussen′s 30-point clinical grading system and Rasmussen′s radiological evaluation of the knee at a minimum follow up of 2 years. Results: Type II was the most common fracture type (9 cases followed by type I (6 cases. There were 37% excellent and 51.85% good functional results with only 3 patients having unacceptable results. The mean Rasmussen′s functional score was 25.062 (range 15-30. Minimal fixation in comminuted or depressed fractures as compared to rigid fixation was the cause of unacceptable results. Loss of knee range of motion in a few cases was attributed to delayed knee mobilization in these cases. Using Rasmussen′s radiological grading, 2 patients had excellent results and 81.48 % patients had good results. Only 3 patients had poor radiological results. The mean Rasmussen′s radiological score was 15.33 (range 10-18. Moreover, clinical evaluation did not correlate with the follow up radiograph. Conclusion: Anatomic reduction and rigid internal fixation followed by early knee motion and partial weight bearing during bone healing are the cornerstones in the treatment of tibial plateau fractures. Standard fracture classification, uniform reporting and evaluating criteria, along with detailed analysis of uniform treatment methods, has helped us

  8. Subtropical circulation, Tibetan Plateau, and Asian Summer Monsoon

    Science.gov (United States)

    Wu, G. X.

    2015-12-01

    The characteristics of the land-air-sea interaction in summer subtropics and their impacts on climate were revealed. It was shown that different kind of diabatic heating plays different roles in the formation of the subtropical circulation where the surface sensible heating associated with the land-sea distribution plays a fundamentally important role, and the three spatial- scales of atmospheric forcing contribute in various ways to the formation of aridity/desert over the western parts of continents and wet/monsoon over the eastern parts. Thus monsoon and desert coexist as twin features. It was identified that the onset of the Asian summer monsoon (ASM) consists of three dynamically consequential stages: the onset first occurs over the eastern Bay of Bengal (BOB) in early May, which is followed by the onset over the South China Sea in mid-May, and the Indian Monsoon onset in early June. During such an onset progression, the formation, maintenance and evolution of the South Asian High (SAH) play a significant role in generating the upper tropospheric dumping. In the lower troposphere, the development of the BOB monsoon onset vortex, the ASM onset barrier, the cross equatorial SST gradient and the forced convection over the eastern Arabian Sea also regulate the onset evolution. In winter the Tibetan Plateau (TP) can inspire a stationary dipole-type atmospheric wave, forming a specific climate pattern in Asia. In spring, such a dipole circulation forms the unique persistent rainfall over Southern China. The TP forcing can also anchor the ASM onset over the BOB by generating the unique short- life BOB SST warm pool and modulating the SAH in the upper troposphere. In summer the thermal forcing of the Tibetan-Iranian Plateau plays a significant role in controlling the Asian monsoon by transporting water vapor from the sea to the land for the genesis of continental monsoon. The TP thermal forcing also modulates the regional climate variability in different time scales.

  9. Measurements of Isotopic Composition of Vapour on the Antarctic Plateau

    Science.gov (United States)

    Casado, M.; Landais, A.; Masson-Delmotte, V.; Genthon, C.; Prie, F.; Kerstel, E.; Kassi, S.; Arnaud, L.; Steen-Larsen, H. C.; Vignon, E.

    2015-12-01

    The oldest ice core records are obtained on the East Antarctic plateau. The composition in stable isotopes of water (δ18O, δD, δ17O) permits to reconstruct the past climatic conditions over the ice sheet and also at the evaporation source. Paleothermometer accuracy relies on good knowledge of processes affecting the isotopic composition of surface snow in Polar Regions. Both simple models such as Rayleigh distillation and global atmospheric models with isotopes provide good prediction of precipitation isotopic composition in East Antarctica but post deposition processes can alter isotopic composition on site, in particular exchanges with local vapour. To quantitatively interpret the isotopic composition of water archived in ice cores, it is thus essential to study the continuum water vapour - precipitation - surface snow - buried snow. While precipitation and snow sampling are routinely performed in Antarctica, climatic conditions in Concordia, very cold (-55°C in average) and very dry (less than 1000ppmv), impose difficult conditions to measure the water vapour isotopic composition. New developments in infrared spectroscopy enable now the measurement of isotopic composition in water vapour traces (down to 20ppmv). Here we present the results of a campaign of measurement of isotopic composition in Concordia in 2014/2015. Two infrared spectrometers have been deployed or the first time on top of the East Antarctic Plateau allowing a continuous vapour measurement for a month. Comparison of the results from infrared spectroscopy with cryogenic trapping validates the relevance of the method to measure isotopic composition in dry conditions. Identification of different behaviour of isotopic composition in the water vapour associated to turbulent or stratified regime indicates a strong impact of meteorological processes in local vapour/snow interaction.

  10. Relationship between gullying and landslides within the Barlad Plateau, Romania

    Science.gov (United States)

    Niacsu, Lilian; Ionita, Ion

    2016-04-01

    Located in the eastern Romania and extending on 8200 km2 the Barlad Plateau is considered the most typical subunit of the Moldavian Plateau. The sedimentary Miocene-Pliocene clay-sandy layers, inter-bedded with shallow sandstone and limestone are gently dipping toward S-SE as homoclinal structure. Land degradation through soil erosion, gullying and landslides represent the most important environmental threat in the region. By using both the classical research methods such as repeated field surveys and mapping, mathematical-statistical processing as well as the present-day methods based on the GIS software it was possible to precisely measure and evaluate the gully erosion rates and triggered landslides during the last two centuries, especially with a very high accuracy since 1960. Results have indicated that the landslide development is strongly controlled by gullying. Generally, by combining the areal growth of both gullying and new landslides within the selected study catchments, it is noticeable that 62 % of the total recent land degradation occurred during the last 55 years, with the remainder pre-1960. In addition, half of the gully areal growth occurred since 1961 but the new triggered landslides amount over three-quarters of the total area under landslides. This asymmetrical distribution reveals that usually a preparing time lag of tens of years is required for triggering landslides by gullying and this pattern depicts the common mechanism for landslide development. Acknowledgements: This work was partly supported by a grant from the Romanian National Authority for Scientific Research, CNDI-UEFISCDI, Project number PN-II-PT-PCCA-2011-3.2-0975.

  11. Sources, atmospheric transport and deposition mechanism of organochlorine pesticides in soils of the Tibetan Plateau.

    Science.gov (United States)

    Chen, Laiguo; Feng, Qianhua; He, Qiusheng; Huang, Yumei; Zhang, Yu; Jiang, Guo; Zhao, Wei; Gao, Bo; Lin, Kui; Xu, Zhencheng

    2017-01-15

    Because of mountain cold-trapping, the soil in the Tibetan Plateau may be an important global sink of organochlorine pesticides (OCPs). However, there are limited data on OCPs in the soils of the Tibetan Plateau. In addition, the atmospheric transport and deposition mechanisms of OCPs also need to be further studied. In this study, the sampling area covered most regions of the Tibetan Plateau. The detection frequencies of ΣChlordane (sum of trans-chlordane, cis-chlordane and oxychlordane), HCB, ΣNonachlor (sum of trans- and cis-nonachlor), DDTs, ΣEndo (sum of endosulfan-I, endosulfan-II and endosulfate), aldrin, HCHs, ΣHeptachlor (sum of heptachlor and heptachlor epoxide), mirex and dieldrin were 100%, 98.3%, 96.6%, 94.8%, 89.7%, 87.9%, 62.1%, 55.2%, 32.8% and 6.9%, respectively. DDTs (with arithmetic mean values of 1050ngkg-1 dw) and HCHs (393ngkg-1) were the principal OCPs in cultivated soils, whereas ΣEndo (192ngkg-1) and ΣChlordane (152ngkg-1) were the principal OCPs in non-cultivated soils. Local use of DDTs, dicofol and HCHs may be an important source of OCP accumulation in the soil of the Tibetan Plateau. Aldrin and endosulfan are considered to be good indicators for studying atmospheric transport and deposition of OCPs from South Asia and Southeast Asia. Two zones with high OCP levels were found in the southeast and northwest of the Tibetan Plateau. The zones have dissimilar pollution sources of OCPs and are influenced by different factors that affect their precipitation scavenging efficiency. The amount of precipitation was the dominant factor in the southeast, whereas large differences in temperature and wind speed were the dominant factors in the northwest. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. 3-D imaging of two episodes of Hikurangi Plateau subduction in the southern South Island of New Zealand

    Science.gov (United States)

    Eberhart-Phillips, D. M.; Reyners, M.; Upton, P.; Gubbins, D.

    2016-12-01

    The Hikurangi Plateau (originally part of the Ontong Java large igneous province) has been subducted beneath New Zealand twice - firstly at ca. 108-105 Ma during north-south convergence with Gondwana, and currently during east-west convergence between the Pacific and Australian plates. We have investigated the southern limit of this subducted plateau by supplementing the sparse GeoNet permanent seismograph network in the southeastern South Island with a forty-station broadband portable seismograph network. We have then used local earthquake tomography to determine detailed 3-D Vp and Vp/Vs structure in the southern South Island. We track a region of Vp 8.5 km/s (which has previously been associated with an eclogite layer at the base of the Hikurangi Plateau from studies in the North Island) across most of the southwestern South Island. Its southeastern edge runs diagonally from near Christchurch to northern Fiordland. It dips both to the northwest and the southwest, and impacts the subducted Australian plate in northern Fiordland, where it currently bends the subducted Australian slab to vertical. The plateau and its leading oceanic crust are distinguished by low Vp/Vs, consistent with extensive dehydration of the thick (ca. 35 km), buoyant plateau during ca. 500 km of flat subduction at the Gondwana margin. The plateau is also revealed by dipping zones of relocated earthquakes. The backstop of Gondwana subduction appears to be the ophiolitic Maitai terrane, which extends through the crust and forms the trenchward boundary of the ca. 60-65 km-thick Median Batholith. We image the low Vp crustal root associated with orogeny at the Gondwana margin in the southeastern South Island, as well as the crustal root resulting from the current convergent episode in the western South Island. The shapes of both crustal roots are controlled by the Hikurangi Plateau.

  13. Annual runoff and evapotranspiration of forestlands and non-forestlands in selected basins of the Loess Plateau of China.

    Science.gov (United States)

    Yanhui Wang; Pengtao Yu; Karl-Heinz Feger; Xiaohua Wei; Ge Sun; et al

    2011-01-01

    Large-scale forestation has been undertaken over decades principally to control the serious soil erosion in the Loess Plateau of China. A quantitative assessment of the hydrological effects of forestation, especially on basin water yield, is critical for the sustainable forestry development within this dry region. In this study, we constructed the multi-annual water...

  14. Long and short term changes in the forests of the Cumberland Plateau and Mountains using large scale forest inventory data

    Science.gov (United States)

    Christopher M. Oswalt; Andrew J. Hartsell

    2012-01-01

    The Cumberland Plateau and Mountains (CPM) are a significant component of the eastern deciduous forest with biological and cultural resources strongly connected to and dependent upon the forest resources of the region. As a result, continuous inventory and monitoring is critical. The USDA Forest Service Forest Inventory and Analysis (FIA) program has been collecting...

  15. Sediment yield dynamics during the 1950s multi-year droughts from two ungauged basins in the Edwards Plateau, Texas

    Science.gov (United States)

    Sediment yield dynamics on the Edwards Plateau region of Texas was dramatically influenced by a multi-year drought that occurred there during the 1950s. To assess the effect of this drought on sediment yield, we used the Soil and Water Assessment Tool (SWAT) to identify the factors that contributed...

  16. Biophysical controls on canopy transpiration in a black locust ( Robinia pseudoacacia ) plantation on the semi-arid Loess Plateau, China

    Science.gov (United States)

    Lei Jiao; Nan Lu; Ge Sun; Eric J. Ward; Bojie Fu

    2015-01-01

    In the semi-arid Loess Plateau of China, black locust (Robinia pseudoacacia) was widely planted for soil conservation and afforestation purposes during the past three decades. Investigating biophysical controls on canopy transpiration (Ec) of the plantations is essential to understanding the effects of afforestation on watershed hydrology and regional water resources....

  17. A stable isotope record of orographic precipitation and continental evaporation across the Central Anatolian Plateau

    Science.gov (United States)

    Schemmel, Fabian; Mikes, Tamas; Rojay, Bora; Mulch, Andreas

    2013-04-01

    The Central Anatolian Plateau (CAP) in central Turkey, much like its larger counterparts in Tibet or the Andes, has a clear influence on regional atmospheric circulations and thus creates a distinct pattern of orographic rainout and rainshadow. Reconstructing these patterns over geological time is a major challenge for understanding the interplay of tectonic and Earth surface processes and their subsequent impact on atmospheric circulation and regional hydrology and ultimately on changes in biodiversity and ecosystems over time. Here we present the first large-scale characterization of hydrogen (δD) and oxygen (δ18O) stable isotopes in precipitation from more than 480 spring and surface water samples from the CAP as well as its northern (Pontic Mts.) and southern (Taurus Mts.) margins. The aim of this study is to quantify the influence of orographic rainout and secondary evaporation on the stable isotopic composition of these meteoric waters and further to establish a robust first-order isotopic template against which continental paleoclimate proxy data can be interpreted. The CAP is bordered by two E-W trending mountain ranges: the Pontic Mountains at the Black Sea coast and the Taurus Mountains at the Mediterranean coast that both serve as major orographic barriers to the transport of moisture, hence developing semi-humid climatic conditions on their windward flanks and arid conditions over the plateau interior. Differences in δD and δ18O values on the northern and southern plateau margins indicate different source regions and are in agreement with observed air parcel trajectories. The orographic rainout on the windward flanks of the Pontic Mountains exhibits isotopic lapse rates of -19 ‰/km for δD and -2.6 ‰/km for δ18O whereas the lapse rates of the Taurus Mountains are slightly higher with -20 ‰/km for δD and -2.9 ‰/km for δ18O across an elevation range of nearly 3000 m. The δD and δ18O values immediate lee of both mountain ranges attain the

  18. Spring maize yield, soil water use and water use efficiency under plastic film and straw mulches in the Loess Plateau

    OpenAIRE

    Lin, Wen; Liu, Wenzhao; Xue, Qingwu

    2016-01-01

    To compare the soil water balance, yield and water use efficiency (WUE) of spring maize under different mulching types in the Loess Plateau, a 7-year field experiment was conducted in the Changwu region of the Loess Plateau. Three treatments were used in this experiment: straw mulch (SM), plastic film mulch (PM) and conventional covering without mulch (CK). Results show that the soil water change of dryland spring maize was as deep as 300?cm depth and hence 300?cm is recommended as the minimu...

  19. Joint analysis of changes in temperature and precipitation on the Loess Plateau during the period 1961-2011

    Science.gov (United States)

    Miao, Chiyuan; Sun, Qiaohong; Duan, Qingyun; Wang, Yafeng

    2016-11-01

    The Loess Plateau is particularly sensitive to climate change owing to its fragile ecological environment and geographic features. Here, we present a comprehensive analysis of the joint probabilistic characteristics and tendencies for bivariate and trivariate precipitation and temperature indices across the plateau, based on copula theory. The results show that the southeast region of the plateau had a higher potential for flooding: the 10-year return levels for the number of days with heavy and very heavy precipitation (R10mm, R20mm) and for the maximum 5-day precipitation value (RX5day) were higher in this region. The northwest region of the plateau, however, had a higher potential for drought, as reflected in the high and increasing 10-year return levels for the number of consecutive dry days (CDD) and the number of days with low precipitation (R1mm). In a joint analysis of precipitation indices, large areas of the Loess Plateau showed a relatively high risk of concurrent extreme precipitation events. However, the risk of concurrent extreme wet and dry events did not increase over the past half century, as demonstrated by nonsignificant changes in the probability of concurrently long CDD and long consecutive wet days (CWD). A trivariate copula analysis showed that some grid locations in the southeast of the plateau had an increasing risk of extreme precipitation events occurring at a high frequency and a high intensity, and forming a large percentage of the annual precipitation. Joint analysis of precipitation and temperature indices showed that the risk of higher temperatures and longer spells of consecutive dry days had increased over the past 50 years in grid locations scattered in the northern and southern regions: there were negative trends in the bivariate return periods for warm days (TX90p) and CDD. In addition, there was a decreased probability of concurrent long spells of consecutive wet days and colder temperatures, as demonstrated by the positive

  20. The quest for peace in Nigeria's Plateau | Odubajo | Africa Insight

    African Journals Online (AJOL)

    Jos, the capital of Plateau State, was the centre of attraction for locals and foreigners alike, as a consequence of its moderate weather, cosmopolitan outlook and tendency for accommodating diversity. For over a decade, however, Jos and various parts of rural Plateau State became theatres of war. The incessant violent ...

  1. Removal of pinyon-juniper woodlands on the Colorado Plateau

    Science.gov (United States)

    Michael Peters; Neil S. Cobb

    2008-01-01

    (Please note, this is an abstract only) Pinyon-Juniper (PJ) woodland is the 3rd largest vegetation type in the United States, covering 35.5% of the Colorado Plateau, it is the largest vegetation type administered by the Bureau of Land Management (BLM) on the Colorado Plateau. These woodlands have been increasing dramatically in density and extent over the last 100...

  2. Orbital measurements among the ethnic groups of Plateau State ...

    African Journals Online (AJOL)

    The aim of this study is to provide a baseline measurements of these orbital parameters for plateau state indigenes of various ethnic groups and to compare with other studies in Nigeria and other countries. The subjects used in this study were 213 medical students of Plateau state studying at University of Jos. Out of the four ...

  3. Plateau Waves of Intracranial Pressure and Multimodal Brain Monitoring.

    Science.gov (United States)

    Dias, Celeste; Maia, Isabel; Cerejo, Antonio; Smielewski, Peter; Paiva, José-Artur; Czosnyka, Marek

    2016-01-01

    The aim of this study was to describe multimodal brain monitoring characteristics during plateau waves of intracranial pressure (ICP) in patients with head injury, using ICM+ software for continuous recording. Plateau waves consist of an abrupt elevation of ICP above 40 mmHg for 5-20 min. This is a prospective observational study of patients with head injury who were admitted to a neurocritical care unit and who developed plateau waves. We analyzed 59 plateau waves that occurred in 8 of 18 patients (44 %). At the top of plateau waves arterial blood pressure remained almost constant, but cerebral perfusion pressure, cerebral blood flow, brain tissue oxygenation, and cerebral oximetry decreased. After plateau waves, patients with a previously better autoregulation status developed hyperemia, demonstrated by an increase in cerebral blood flow and brain oxygenation. Pressure and oxygen cerebrovascular reactivity indexes (pressure reactivity index and ORxshort) increased significantly during the plateau wave as a sign of disruption of autoregulation. Bedside multimodal brain monitoring is important to characterize increases in ICP and give differential diagnoses of plateau waves, as management of this phenomenon differs from that of regular ICP.

  4. Users Satisfaction with Library and Information Service in Plateau ...

    African Journals Online (AJOL)

    The study investigated Users Satisfaction with Library and Information Service in Plateau State Special Education Institution. Survey research method was adopted for the study and the population of the study consists of staff and students of the special educational institutions in Plateau State. The three selected institutions ...

  5. Tibetan Plateau capacitor effect during the summer preceding ENSO: from the Yellow River climate perspective

    Science.gov (United States)

    Jin, Rui; Wu, Zhiwei; Zhang, Peng

    2017-09-01

    It is well recognized that El Niño-Southern Oscillation (ENSO) may exert a direct impact on the East Asian summer monsoon rainfall through modulating the Philippine Sea anticyclone variability. Such ENSO associated influence is evident in the monsoon region, i.e., Southeast China, the Yangtze River, Korean Peninsula and Japan. It remains unclear whether and how this ENSO related effect can reach the Yellow River region, a monsoon/arid transition region. In this study, results show that the year-to-year variations of the Yellow River summer rainfall can be indirectly influenced by ENSO, during its developing phase. The western Tibetan Plateau snow cover (WTPSC) may act as a "capacitor", helping ENSO signal to reach the Yellow River region. During the El Niño developing spring, the associated diabatic heating in Pacific region can excite an anomalous cyclone over the plateau and anomalous upward flows over the western plateau. Such circulation configuration favors an excessive WTPSC anomaly in spring. The more WTPSC may increase the surface albedo, decrease the absorbed net shortwave radiation and in turn intensify the WTPSC. Through such snow-albedo feedback process, the excessive WTPSC anomaly may strengthen and persist through summer, which may induce two noticeable wave trains in the upper and lower troposphere propagating northeastward to the Yellow River region. Associated with the wave trains, a low pressure anomaly prevails over northeast China. To the southwest side of the anomalous low pressure, the abnormal northerly wind may bring large volumes of dry cold air with little moisture to the Yellow River region, leading to the anomalous drought there. During the La Niña developing summer, the situation tends to be opposite. As such, the ENSO associated influence is tied to the interannual variations of the following summer Yellow River precipitation, with the development of ENSO from spring.

  6. Parhelic-like circle from light scattering in Plateau borders

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, A., E-mail: tufaile@usp.br; Tufaile, A.P.B.

    2015-03-06

    We are reporting a new simple optical element to generate halos. We have observed interesting patterns of light scattering in Plateau borders in foams. In analogy to the atmospheric phenomena known as parhelic circle, sun dogs, and sun pillars, we have named the features of the patterns observed as parlaseric circle, laser dogs, and laser pillars. The triangular symmetry of the Plateau borders is analogous to the hexagonal symmetry of ice crystals which produce these atmospheric phenomena. Working with one Plateau border at a time, we have observed wave optics phenomena that are not perceived in the atmospheric phenomena, such as diffraction and interference. - Highlights: • We obtained halo formation from light scattering in a Plateau border using an experiment. • We explained halo formation using geometrical theory of diffraction. • An optical element based on a Plateau border is proposed. • We compared some aspects of the parhelic circle with the parlaseric circle.

  7. Magnetolluric Imaging of the Lithosphere beneath the Tibetan Plateau: A Synoptic View

    Science.gov (United States)

    Dong, H.; Wei, W.; Jin, S.; Ye, G.; Jing, J.; Zhang, L.; Jones, A. G.; Xie, C.; Yin, Y.

    2016-12-01

    To better understand the collision and convergence process between India and Asia continent, magnetotelluric (MT) data have been used to image crustal electrical resistivity and to estimate the rheological structure in the south, east and north margin of Tibetan Plateau in the last decades. However, most of these MT data were collected as isolated profiles and insufficient to convey a synoptic view of the Plateau. Recently, the MT data coverage is greatly improved from the 1 by 1 degree SINOPROBE MT array data from 2011-2013. In this study, a three-dimensional (3D) geo-electrical model of the crust and uppermost mantle is derived from the combined broadband and long period array dataset. The resulting model features broadly resistive structure in the upper crust, with the exception of small scale conductors lining along the Yarlung-Zangbo Suture (YZS) and Bangong-Nujiang Suture (BNS). The lower crust consists of widely spread high conductive structures beneath Lhasa and Qiangtang Block except for the southeast part of Tibetan Plateau. Instead of the previous proposed homogenous high conductive layer, these lower crustal conductors are generally N-S directed and perpendicular to the above Cenozoic and Mesozoic sutures. While the lower crustal structures probably indicate partial melts induced by radiogenic heat from the thickened crust, the conductor along the suture zones in the upper crust might imply pathways for deep fluids into the shear zones of YZS and BNS. One of the most prominent feature revealed is the upper mantle conductive sturcture in the central part of Tibet Plateau (85-92°E) accompanied by two resistive regions in the southeast and southwest part of the Plateau. While the southwest resistive zone is broadly consistent with the "flat subduction" region of Indian lithosphere revealed by seismic receiver function study, the conductive middle part of Tibetan Plateau might represent the upper mantle melts induced by the water carried by the steeper

  8. Evaluating the coupling effects of climate aridity and vegetation restoration on soil erosion over the Loess Plateau in China.

    Science.gov (United States)

    Zhang, Baoqing; He, Chansheng; Burnham, Morey; Zhang, Lanhui

    2016-01-01

    In this study, the coupling effects of climate aridity and vegetation restoration on runoff and sediment yield over the Loess Plateau were examined and characterized. To take into consideration the complexity of drought, as well as the varied strengths and weaknesses of different drought measures, two drought indices are selected to identify and evaluate drought variability. The Normalized Difference Vegetation Index (NDVI) data were obtained to monitor and express spatiotemporal variations in vegetation cover. The results show that most regions of the Loess Plateau experienced increasingly severe droughts over the past 40years, and these regions comprise the major source of the Yellow River sediment. Climatic drying initially occurred in the 1990s, and became statistically significant in 2000s. The increasingly severe droughts could negatively impact surface and groundwater supplies as well as soil water storage, but may also minimize surface runoff yield, which is one of the major causes of soil erosion on the Loess Plateau. Vegetation cover on the Loess Plateau was significantly improved after the implementation of "Grain for Green" project, which were helpful for controlling severe soil erosion. With the impacts of the construction of check dams, terraces and large reservoirs, runoff and sediment yield over the Loess Plateau initially exhibited downward trends between 1970 and 1990. After 1990, with the effects of the climate warming and drying, a second sharp reduction in runoff and sediment yield occurred. The coupling effects of climate aridity and vegetation restoration have led to a third significant decrease in runoff and sediment yield over the Loess Plateau after 2000. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. The Colorado Plateau V: research, environmental planning, and management for collaborative conservation

    Science.gov (United States)

    Villarreal, Miguel L.; van Riper, Carena J.; Johnson, Matthew J.; van Riper, Charles

    2012-01-01

    Roughly centered on the Four Corners region of the southwestern United States, the Colorado Plateau covers some 130,000 square miles of sparsely vegetated plateaus, mesas, canyons, arches, and cliffs in Arizona, Utah, Colorado, and New Mexico. With elevations ranging from 3,000 to 14,000 feet, the natural systems found within the plateau are dramatically varied, from desert to alpine conditions. This volume, the fifth from the University of Arizona Press and the tenth overall, focuses on adaptation of resource management and conservation to climate change and water scarcity, protecting biodiversity through restructured energy policies, ensuring wildlife habitat connectivity across barriers, building effective conservation networks, and exploring new opportunities for education and leadership in conservation science. An informative read for people interested in the conservation and natural history of the region, the book will also serve as a valuable reference for those people engaged in the management of cultural and biological resources of the Colorado Plateau, as well as scientists interested in methods and tools for land and resource management throughout the West.

  10. Petrologic Evolution of Karayazı Basaltic Plateau: Mixture of melts-derived from both spinel and garnet lherzolite

    Science.gov (United States)

    Oyan, Vural; Özdemir, Yavuz; Jourdan, Fred

    2016-04-01

    Collision-related volcanism in Eastern Anatolia spreads in a wide zone from the Erzurum-Kars Plateau in the northeast to the Karacadaǧ in the south. Volcanic activity in the region started 15 Ma ago (Middle Miocene) in the south of region following the continent-continent collision between Arabian and Eurasia plates, and continued up to historical times. Voluminous basaltic lava plateaus and basaltic lavas from local eruption centers occurred as a result of high production level of volcanism during the Pliocene time interval. Karayazı basatic lava area located in the Northeast of Turkey is one of the most important and largest basaltic plateau in the East Anatolia. This area which is named to be Karayazı basaltic plateau has covered an area of approximately 200 km2. Lavas of the Karayazı basaltic plateau are characterized with alkali and subalkali basalt erupted from different centers up to from Miocene to Quaternary times. Lavas of the Karayazı basaltic plateau is characterized by alkali olivine basalts and subalkali basalts. These lavas are composed of olivine, plagioclase, augite and titanoaugite crystals and display porphyritic to aphyric textures. Sr, Nd and Hf isotopic compositions of the basaltic plateau vary between 0.703396-0.704976, 0.512730-0.512918 ve 0.282002-0.283029, respectively. MORB pattern of the lavas and isotopic composition imply that alkali and subalkali basalts erupted from Karayazı plateau could have been derived from a mantle source that had previously been enriched by a distinct subduction component. A partial melting model was conducted to evaluate partial melting processes in mantle source of the alkali and subalkali basalts. Results of this model suggest the presence of both strongly spinel and slightly garnet peridotite in the source, a partial melting degree of 2-10 % and mixing of the derivative melts from them in the genesis of the Karayazı basaltic volcanism. All these findings indicate that the source region of the Karayaz

  11. Soil erosion assessment in the core area of the Loss Plateau

    Science.gov (United States)

    Yang, Bo; Wang, Quanjiu

    2017-11-01

    In order to explore the spatiotemporal evolution of erosion and sediment yield before and after Grain for Green Project in the Loss Plateau. The soil loss of Yulin is estimated by Chinese Water Erosion on Hill Slope Prediction Model. The result shows that the spatiotemporal variations of soil erosion are largely related to rainfall erosion distribution, slope, and land use type. The overall soil erosion categories in the south region are higher than that of the northwest. Mid slopes and valleys are the major topographical contributors to soil erosion. With the growth of slope gradient, soil erosion significantly increased. The soil loss has a decreasing tendency after Grain for Green Project. The results indicate that the vegetation restoration as part of the Grain for Green Project on the Loess Plateau is effective.

  12. Ozone and hydrogen peroxide during summer smog episodes over the Swiss Plateau: Measurements and model simulations

    Science.gov (United States)

    Dommen, Josef; Neftel, Albrecht; Sigg, Andreas; Jacob, Daniel J.

    1995-05-01

    As part of the POLLUMET (Pollution and Meteorology in Switzerland) study, measurements of O3, NO2, and H2O2 were made at ground stations, by aircraft, and manned hydrogen balloons to characterize the photochemical processes prevailing during times of high ozone production. During summer smog episodes, elevated ozone concentrations were found over the whole area of the Swiss Plateau, which is a densely populated and industrialized region. However, NO2 concentrations were generally at a low level in the afternoon. An increase of hydrogen peroxide concentration in the mixing layer during photochemical episodes was observed. To understand better the photochemical processes which control ozone formation over the Swiss Plateau, calculations with the Harvard photochemical model and the Harwell photochemical trajectory model were conducted. A comparison of model results with measurements of the triad O3, NO2, and H2O2 indicates an ozone formation under low NOx conditions.

  13. Influence of the Tibetian Plateau on cumulative and diurnal changes of weather and climate in summer

    Science.gov (United States)

    Kuo, H. L.; Qian, Y. F.

    1981-01-01

    An investigation of the dynamic and thermodynamic influences of the Tibetian Plateau on the monsoon circulation in southeastern Asia and China is reported. A five-day primitive equation numerical model was used to simulate the influences of the high mountains in the 0-180 deg E and 25-55 deg N region on a typical July day. The equations predicted horizontal motion, heat, the water vapor mixing ratio, and surface pressure. Consideration was given to solar and longwave radiation and the release of latent heat by deep cumulus clouds. A net warming over the Plateau as opposed to the surrounding areas was found to lead to vertical air ascent and the establishment of strong summer monsoon circulation to the south. It is noted that the grid was too coarse to adequately describe the distribution of precipitation on the steep mountains.

  14. Loess Plateau storage of Northeastern Tibetan Plateau-derived Yellow River sediment.

    Science.gov (United States)

    Nie, Junsheng; Stevens, Thomas; Rittner, Martin; Stockli, Daniel; Garzanti, Eduardo; Limonta, Mara; Bird, Anna; Andò, Sergio; Vermeesch, Pieter; Saylor, Joel; Lu, Huayu; Breecker, Daniel; Hu, Xiaofei; Liu, Shanpin; Resentini, Alberto; Vezzoli, Giovanni; Peng, Wenbin; Carter, Andrew; Ji, Shunchuan; Pan, Baotian

    2015-10-09

    Marine accumulations of terrigenous sediment are widely assumed to accurately record climatic- and tectonic-controlled mountain denudation and play an important role in understanding late Cenozoic mountain uplift and global cooling. Underpinning this is the assumption that the majority of sediment eroded from hinterland orogenic belts is transported to and ultimately stored in marine basins with little lag between erosion and deposition. Here we use a detailed and multi-technique sedimentary provenance dataset from the Yellow River to show that substantial amounts of sediment eroded from Northeast Tibet and carried by the river's upper reach are stored in the Chinese Loess Plateau and the western Mu Us desert. This finding revises our understanding of the origin of the Chinese Loess Plateau and provides a potential solution for mismatches between late Cenozoic terrestrial sedimentation and marine geochemistry records, as well as between global CO2 and erosion records.

  15. Plateau inflation in SUGRA-MSSM

    Directory of Open Access Journals (Sweden)

    Girish Kumar Chakravarty

    2016-09-01

    Full Text Available We explored a Higgs inflationary scenario in the SUGRA embedding of the MSSM in Einstein frame where the inflaton is contained in the SU(2 Higgs doublet. We include all higher order non-renormalizable terms to the MSSM superpotential and an appropriate Kähler potential which can provide slow-roll inflaton potential in the D-flat direction. In this model, a plateau-like inflation potential can be obtained if the imaginary part of the neutral Higgs acts as the inflaton. The inflationary predictions of this model are consistent with the latest CMB observations. The model represents a successful Higgs inflation scenario in the context of Supergravity and it is compatible with Minimal Supersymmetric extension of the Standard Model.

  16. Behavioral mechanisms of male sterilization on plateau pika in the Qinghai-Tibet plateau.

    Science.gov (United States)

    Liu, Ming; Qu, Jiapeng; Wang, Zengli; Wang, Yan-Ling; Zhang, Yanming; Zhang, Zhibin

    2012-03-01

    Fertility control is an alternative non-lethal method in the management of rodents. Previous modeling suggests that the efficacy of male sterilization depends on mating systems of animals, but behavioral mechanisms of male sterilization have not been investigated. Here we investigated the behavioral mechanism of the sterilant quinestrol in reducing the fertility of plateau pika (Ochotona curzoniae) inhabiting the Qinghai-Tibet plateau. Male pikas treated with quinestrol showed reduced aggression compared to control males, but they showed significantly higher levels of territorial behavior such as long-calls and long-chases. Levels of long-call and long-chase were negatively correlated with the number of newborn pikas in the family. Single-baiting of quinestrol effectively sterilized male pikas and reduced the pregnancy rate of female pikas; this was likely achieved by increased territorial behavior of sterilized pikas which resulted in unsuccessful invasions by fertile adult male pikas. Our study reveals a novel behavioral mechanism, increased territoriality in sterilized males, in the fertility control of plateau pikas. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Integrated Research Plan on the Tibetan Plateau Land-Air Coupled System and Its Impact on Global Climate Change

    Science.gov (United States)

    Wu, G. X.; Zhou, X.; Cai, Y.; Liu, Y.; Zhang, C.

    2016-12-01

    The Tibetan Plateau (TP) accounts for nearly one-quarter of the total land area of China and is known as the highest plateau in the world with an average elevation of four kilometers. The mechanical and thermal effects of the giant plateau, together with the in situ land-air coupled system, plays an important role in the formation of the general circulation pattern, the regional weather and climate regimes, the multi-scale variability of the Asian summer monsoon, and even the global atmospheric energy and water cycle. However, due to the lack of observational data, the defects in the existing land and atmosphere models, and the poor knowledge of interactions between land surface and atmosphere over the TP, our understanding on the complicated energy and water cycles over the TP and their effects on regional and global weather and climate is limited, the prediction skill of high-impact weather over the plateau and its surrounding regions is still unsatisfactory, and the Asian monsoon area suffers from the largest climate prediction errors. In 2012, the Chinese Meteorological Administration (CMA) launched an ambitious 10-year program aiming at improving the meteorological observation systems over the TP and its surrounding provinces. Accordingly, a 10-year national research program beginning from 2013 and entitled "Land-Air coupled System over the Tibetan Plateau and its Impacts on global Climate (LASTPIC)" has been launched by the National Natural Science Foundation of China (NSFC). The overall scientific goals of this program includes: to further understand the land-air coupling processes; to develop a land-air data assimilation system in the TP domain and establish the corresponding data bank; to improve the regional and global climate models; and to explore the mechanism of the TP weather and climate impacts. The introduction of this NSFC program will be presented.

  18. Accumulation and erosion of aeolian sediments in the northeastern Qinghai-Tibetan Plateau and implications for provenance to the Chinese Loess Plateau

    Science.gov (United States)

    Liu, Xiang-Jun; Xiao, Guoqiao; E, Chongyi; Li, Xiangzhong; Lai, Zhongping; Yu, Lupeng; Wang, Zhong

    2017-03-01

    The northern and northeastern Qinghai-Tibetan Plateau (QTP) is regarded as one important source region of the Chinese Loess Plateau (CLP). However, how the fine grain sediments in this region were transported to the CLP remains debatable. In this study, we dated aeolian sediments, alluviums, beach sediments, and sand wedges in the northeastern QTP using optical dating, combined with previously reported ages, explored the aeolian sediment deposition patterns in this region. The dating results shown that aeolian sediments mainly accumulated during the marine isotope stage (MIS) 3 and since the last deglaciation, alluvial sediments mainly deposited during the middle to late MIS 3 (between ∼40 ka and 22 ka), and sand wedges formed during the MIS 4 and MIS 2 cold intervals. Based on the sedimentary stratigraphic characteristics and existing optical dating chronologies, we propose that fine grain sediments in the northern and northeastern QTP were eroded and carried to the CLP by westerly wind during last glacial and stadial cold stages. However, during last interglacial and interstadial warm stages, aeolian sediments deflated from western barren lands and deserts were mainly trapped in the northeastern QTP, and some were transported to the Alax arid zone or Yinchuan-Hetao plain by rivers that flow out of QTP, then transported to the CLP by northwesterly Asian winter monsoon (AWM). This cold stage westerly wind transport, warm stage rivers plus AWM transport pattern has existed at least since the late middle Pleistocene.

  19. Two distinct patterns of seasonal variation of airborne black carbon over Tibetan Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Mo; Xu, Baiqing; Wang, Ninglian; Cao, Junji; Tie, Xuexi; Wang, Hailong; Zhu, Chongshu; Yang, Wei

    2016-12-01

    Airborne black carbon (BC) mass concentrations were measured from November 2012 to June 2013 at Ranwu and Beiluhe, located in the southeastern and central Tibetan Plateau, respectively. Monthly mean BC concentrations showawinter (November–February) high (413.2 ng m$-$3) and spring (March–June) low(139.1 ng m$-$3) at Ranwu, but in contrast awinter lowand spring high at Beiluhe (204.8 and 621.6 ng m$-$3, respectively). By examining the meteorological conditions at various scales, we found that themonthly variation of airborne BC over the southeastern Tibetan Plateau (TP) was highly influenced by regional precipitation and over the hinterland by winds. Local precipitation at both sites showed little impact on the seasonal variation of airborne BC concentrations. Potential BC source regions are identified using air mass backward trajectory analysis. At Ranwu, BC was dominated by the air masses from the northeastern India and Bangladesh in both winter and spring, whereas at Beiluhe it was largely contributed by air masses from the south slope of Himalayas in winter, and from the arid region in the north of the TP in spring. Thewinter and spring seasonal peak of BC in the southern TP is largely contributed by emissions from South Asia, and this seasonal variation is heavily influenced by the regional monsoon. In the northern TP, BC had high concentrations during spring and summer seasons, which is very likely associated with more efficient transport of BC over the arid regions on the north of Tibetan Plateau and in Central Asia. Airborne BC concentrations at the Ranwusampling site showed a significant diurnal cyclewith a peak shortly after sunrise followed by a decrease before noon in both winter and spring, likely shaped by local human activities and the diurnal variation of wind speed. At the Beiluhe sampling site, the diurnal variation of BC is different and less distinct.

  20. Pliocene onset of widespread normal faulting in the southern Puna Plateau, southern central Andes, NW Argentina

    Science.gov (United States)

    Montero Lopez, M. C.; Hongn, F. D.; Marrett, R.; Seggiaro, R.; Strecker, M. R.

    2009-12-01

    Normal faults are often observed in many compressional Cenozoic mountain belts and paleotectonic settings and have been associated with a late-stage development in orogen evolution. Often, such normal faults are found in high-elevation sectors in the orogen interior and may form graben, closely spaced arrays or they are kinematically linked with strike-slip faults. In contrast, at lower elevations and in the adjacent foreland regions coeval shortening may be sustained. This situation typifies the active tectonics of the southern central Andes of NW Argentina characterized by the Puna Plateau (22° to 27° S lat), the world’s second largest orogenic plateau with an average elevation of 3.7 km and the adjacent Andean foreland. The Puna contains neotectonic landforms that host widespread active normal faults, closely associated with mafic centres. In contrast, the shortening continued in the foreland. The onset of the extensional kinematic in the Puna has been inferred to be Quaternary in age as many mafic volcanic manifestations were generated during the ultimate 2 Ma. However, our new structural observations and Ar/Ar dating of volcanic deposits and dykes suggests that widespread extension in the Puna started much earlier. We are able to show that the southern margin of the Puna is characterized by extensional structures at different length scales, including extensional fractures, sometimes hosting dykes, as well as normal fault arrays that cut volcanic edifices and flows, visible on satellite imagery. Fault kinematic analysis and an assessment of dyke and fracture orientations documents that the region at about 27°S lat is affected by N-S extension. This must be a regional phenomenon as similar observations can be made in areas farther north as well. Our geochronology work on lava flows and dykes in this region suggests that an extensional regime may have been in existence by 7-6 Ma and extensional processes were well underway by 4 Ma. The often observed

  1. The seismic wave speed structure of the Ontong Java Plateau determined from joint ambient noise and earthquake waveform data

    Science.gov (United States)

    Covellone, B. M.; Savage, B. K.; Shen, Y.

    2014-12-01

    The Ontong Java Plateau (OJP) represents the result of a significant event in the Earth's geologic history. Limited geophysical and geochemical data, as well as the plateau's relative isolation in the Pacific Ocean, have made interpretation of the modern day geologic structure and its 120 Ma formation history difficult. Here we present the highest resolution images to date of the wave speed structure of the OJP region. We use an iterative finite-frequency tomography methodology and a unique data set that combines empirical Green's functions extracted from ambient noise and earthquake waveforms. The uniqueness and combination of datasets allow us to best exploit the limited station distribution in the Pacific and image wave speed structures between 35 km and greater than 250 km into the Earth. We image a region of fast shear wave speeds, greater than 4.75 km/s, that extends to greater than 100 km beneath the plateau. The wave speeds are similar to as observed in cratonic environments and are consistent with a compositional anomaly likely a result of eclogite entrainment during the plateau's formation.

  2. Monitoring of aeolian desertification on the Qinghai-Tibet Plateau from the 1970s to 2015 using Landsat images.

    Science.gov (United States)

    Zhang, Chun-Lai; Li, Qing; Shen, Ya-Ping; Zhou, Na; Wang, Xue-Song; Li, Jiao; Jia, Wen-Ru

    2017-10-21

    Aeolian desertification, one of the most serious environmental issues, has hampered socioeconomic development on the Qinghai-Tibet Plateau (QTP). However, research on aeolian desertification in this region has been limited. To develop a set of science-based preventive measures to mitigate desertification in this region, it is first necessary to clarify the status, evolution, and driving factors of aeolian desertification. In this study, based on extensive field investigations and a current classification system for aeolian desertification, we established a new system for interpreting aeolian desertified land (ADL) on the plateau using Landsat images from 1977, 1990, 2000, 2010, and 2015 and obtained the distribution of ADL through visual interpretation of the images. The results showed that ADL covered 392,914km2 (15.1% of the study area) in 2015, including gravel ADL, sandy ADL, and aeolian monadnocks. Controlled by climate, landforms, the type of Quaternary deposit, and human activities, ADL is scattered throughout the plateau but is concentrated mostly in the western and northern parts. Aeolian desertification on the plateau expanded from 1977 to 2000 and then began to reverse. The evolution during the study period is the result of the combined effects of natural and human factors. Irrational human activities were the dominant factor responsible for the expansion of ADL prior to 2000, whereas the subsequent reversal was mainly caused by climate change combined with large ecological restoration projects. Copyright © 2017. Published by Elsevier B.V.

  3. Depth-dependent seismic anisotropy beneath the Turkish-Anatolian Plateau from SKS and Ps splitting analysis

    Science.gov (United States)

    Kaviani, Ayoub; Rumpker, Georg

    2017-04-01

    In this study we investigate seismic anisotropy across the Turkish-Anatolian Plateau by joint analysis of shear-wave splitting of SKS and Moho-converted P-to-S phases. With this approach we are able to decipher the different contributions of crustal and mantle anisotropy. We process SKS waveforms and teleseismic receiver functions at more than 120 broad-band stations operated across the Turkish-Anatolian Plateau during the last decade. The complete data set and the joint approach allow for the investigation of lateral and depth variations of seismic anisotropy across this tectonically active region. The results of the SKS splitting analysis illustrate systematic azimuthal variations in splitting parameters at many stations. Furthermore, the Ps splitting analysis of receiver functions at some stations reveals significant crustal anisotropy. By correcting for the influence of crustal anisotropy on the SKS splitting, we obtain splitting parameters that are directly linked to the mantle anisotropy. The crustal anisotropy show significant lateral variations across the tectonic boundaries between different crustal fragments in the plateau. This pattern implies the signature of tectonic structures. The corrected mantle anisotropy shows a relatively uniform pattern across the plateau implying that the main part of the mantle anisotropy is caused by the relative motion of the lithospheric plate over the underlying asthenosphere. We intend to extend this approach to cover the entire region of the Middle East.

  4. Strontium isotope evidence for a highly mobile population on the Pamir Plateau 2500 years ago

    Science.gov (United States)

    Wang, Xueye; Tang, Zihua; Wu, Jing; Wu, Xinhua; Wu, Yiqun; Zhou, Xinying

    2016-10-01

    Archeological researches have proposed arguments for human mobility and long-distance trading over the Eurasia before the Silk Roads. Here we utilize biologically available strontium isotope analysis to assess the extent of pre-Silk Road population movements and cultural communications across the Asian interior. From an early Iron Age cemetery (ca. 2500 yr B.P.) on the eastern Pamir Plateau, mean 87Sr/86Sr ratios from 34 individuals display considerable isotopic variability, and 10 individuals are distinguished as migrants based on the local strontium isotope range of 0.710296-0.710572 defined by 12 ovicaprine bones. Comparison of the proportion (10/34) with the regional census data completed in 1909 A.D. (3% non-locals) suggests a highly migratory behavior on the plateau 2500 years ago. Furthermore, exotic mortuary objects, such as silk fabrics from eastern China and angular harp originated from the Near East, clearly demonstrate an interaction between different cultures on the plateau before the establishment of the Silk Road.

  5. Qinghai-Tibet Plateau crustal thickness derived from EGM2008 and CRSUT2.0

    Directory of Open Access Journals (Sweden)

    Zhou Hao

    2014-11-01

    Full Text Available Qinghai-Tibet Plateau is the most complex region for crustal thickness inversion, while high-resolution earth gravity model (EGM makes it possible to obtain high precision gravity anomaly, which is a key parameter to depict the Earth’s inner structure in geodesy domain. On the basis of this principle, we calculated the Bouguer gravity anomalies in Qinghai-Tibet Plateau with EGM2008 and SRTM6. 0 by efficient high-degree spherical harmonic synthesis algorithm. In order to obtain the gravity anomaly caused by Moho density mutant, the noises caused by the topography was removed by wavelet details. Then, the crustal thickness was corrected on the basis of CRUST 2. 0 with the deep-large-scale single density interface formula. The inversion result indicates that the crustal thickness in Qinghai-Tibet Plateau is between 50 km and 75 km, which is in correspondence with the recent science research result. Compared with the 2 degree CRUST 2. 0 model, the spatial resolution of crustal thickness in our research can reach 40 arc minutes. In addition, there is a positive relationship between the inversed crustal thickness and topography, which can prove the effectiveness of Airy-Heiskanen isostatic model in gravity reduction.

  6. Modeling and Mapping Soil Moisture of Plateau Pasture Using RADARSAT-2 Imagery

    Directory of Open Access Journals (Sweden)

    Xun Chai

    2015-01-01

    Full Text Available Accurate soil moisture retrieval of a large area in high resolution is significant for plateau pasture. The object of this paper is to investigate the estimation of volumetric soil moisture in vegetated areas of plateau pasture using fully polarimetric C-band RADARSAT-2 SAR (Synthetic Aperture Radar images. Based on the water cloud model, Chen model, and Dubois model, we proposed two developed algorithms for soil moisture retrieval and validated their performance using experimental data. We eliminated the effect of vegetation cover by using the water cloud model and minimized the effect of soil surface roughness by solving the Dubois equations. Two experimental campaigns were conducted in the Qinghai Lake watershed, northeastern Tibetan Plateau in September 2012 and May 2013, respectively, with simultaneous satellite overpass. Compared with the developed Chen model, the predicted soil moisture given by the developed Dubois model agreed better with field measurements in terms of accuracy and stability. The RMSE, R2, and RPD value of the developed Dubois model were (5.4, 0.8, 1.6 and (3.05, 0.78, 1.74 for the two experiments, respectively. Validation results indicated that the developed Dubois model, needing a minimum of prior information, satisfied the requirement for soil moisture inversion in the study region.

  7. Observational Evidence of EHP Effects on the Melting of Snowpack over the Tibetan Plateau

    Science.gov (United States)

    Kim, Maeng-Ki; Lau, William K. M.; Kim, Kyu-Myong; Lee, Woo-Seop

    2012-01-01

    Observational evidences are presented showing that the Indo-Gangetic Plain (IGP) regions, bounded by the high altitude Himalayan mountains, are subject to heavy loading of absorbing aerosols, i.e., black carbon and dust, which can lead to widespread enhancement warming over the Tibetan Plateau and accelerated snowmelt in the western Tibetan Plateau (WTP) and Himalayas. The two pre-monsoon seasons of 2004 and 2005 were strikingly contrasting in terms of the aerosol loading over IGP. The warming of the TP in 2004 relative to 2005 was widespread, covering most of the WTP and Himalayas. This warming is closely linked to patterns of the snow melt. Consistent with the Elevated Heat Pump hypothesis, we find that increased loading of absorbing aerosols over IGP in the pre-monsoon season is associated with increased heating of the upper troposphere by dynamical feedback induced by aerosol heating, and enhances the rate of snowmelt over Himalayas and the WTP in April-May. Composite analysis with more contrasting years also shows that the heating of the troposphere by elevated dust and black carbon aerosols in the boreal spring can lead to widespread enhanced land-atmosphere warming, and accelerated snow melt in the Himalayas and Tibetan Plateau.

  8. Indices for estimating fractional snow cover in the western Tibetan Plateau

    Science.gov (United States)

    Shreve, Cheney M.; Okin, Gregory S.; Painter, Thomas H.

    Snow cover in the Tibetan Plateau is highly variable in space and time and plays a key role in ecological processes of this cold-desert ecosystem. Resolution of passive microwave data is too low for regional-scale estimates of snow cover on the Tibetan Plateau, requiring an alternate data source. Optically derived snow indices allow for more accurate quantification of snow cover using higher-resolution datasets subject to the constraint of cloud cover. This paper introduces a new optical snow index and assesses four optically derived MODIS snow indices using Landsat-based validation scenes: MODIS Snow-Covered Area and Grain Size (MODSCAG), Relative Multiple Endmember Spectral Mixture Analysis (RMESMA), Relative Spectral Mixture Analysis (RSMA) and the normalized-difference snow index (NDSI). Pearson correlation coefficients were positively correlated with the validation datasets for all four optical snow indices, suggesting each provides a good measure of total snow extent. At the 95% confidence level, linear least-squares regression showed that MODSCAG and RMESMA had accuracy comparable to validation scenes. Fusion of optical snow indices with passive microwave products, which provide snow depth and snow water equivalent, has the potential to contribute to hydrologic and energy-balance modeling in the Tibetan Plateau.

  9. Integrated assessment on the vulnerability of animal husbandry to snow disasters under climate change in the Qinghai-Tibetan Plateau

    Science.gov (United States)

    Wei, Yanqiang; Wang, Shijin; Fang, Yiping; Nawaz, Zain

    2017-10-01

    Animal husbandry is a dominant and traditional source of livelihood and income in the Qinghai-Tibetan Plateau. The Qinghai-Tibetan Plateau is the third largest snow covered area in China and is one of the main snow disaster regions in the world. It is thus imperative to urgently address the issue of vulnerability of the animal husbandry sector to snow disasters for disaster mitigation and adaptation under growing risk of these disasters as a result of future climate change. However, there is very few literature reported on the vulnerability of animal husbandry in the Qinghai-Tibetan Plateau. This assessment aims at identifying vulnerability of animal husbandry at spatial scale and to identify the reasons for vulnerability for adaptive planning and disaster mitigation. First, historical snow disaster characteristics have been analyzed and used for the spatial weight for vulnerability assessment. Second, indicator-based vulnerability assessment model and indicator system have been established. We combined risk of snow hazard, sensitivity of livestock to disaster, physical exposure to disaster, and community capacity to adapt to snow disaster in an integrated vulnerability index. Lastly, vulnerability of animal husbandry to snow disaster on the Qinghai-Tibetan Plateau has been evaluated. Results indicate that high vulnerabilities are mainly concentrated in the eastern and central plateau and that vulnerability decreases gradually from the east to the west. Due to global warming, the vulnerability trend has eased to some extent during the last few decades. High livestock density exposure to blizzard-prone regions and shortages of livestock barn and forage are the main reasons of high vulnerability. The conclusion emphasizes the important role of the local government and community to help local pastoralists for reducing vulnerability to snow disaster and frozen hazard. The approaches presented in this paper can be used for snow disaster mitigation, resilience

  10. Temporal and spatial evolution of the standardized precipitation evapotranspiration index (SPEI) in the Loess Plateau under climate change from 2001 to 2050.

    Science.gov (United States)

    Gao, Xuerui; Zhao, Qi; Zhao, Xining; Wu, Pute; Pan, Wenxiang; Gao, Xiaodong; Sun, Miao

    2017-10-01

    Loess Plateau has great uncertainty on drought occurrence due to climate change. This paper analyzes the evolution of precipitation, potential evapotranspiration and standardized precipitation evapotranspiration index (SPEI) based on the Coupled Model Inter-comparison Project Phase 5 (CMIP5) data and regional downscaling model (RegCM4.0). Results indicate that, under RCP2.6 Scenario, the precipitation will increase significantly (5% confidence level) at the rate of 16.40mm/10a. However, the potential evapotranspiration is showing non-significant decreasing trend at the rate of 2.16mm/10a. Moreover, the SPEI will decrease in the south and northernmost area and increase in the central northern area of Loess Plateau. Under RCP8.5 Scenario, the precipitation will increase significantly (5% confidence level) at the rate of 19.12mm/10a. The potential evapotranspiration will non-significantly decrease at the rate of 2.16mm/10a and the SPEI is showing increasing trend almost in the whole Loess Plateau. Generally, Loess Plateau is becoming wetter in the central part under RCP2.6 Scenario and the wet area will be enlarged to almost the whole plateau under RCP8.5 Scenario. Based on the results, the water resources will increase under global warming, which may alleviate the water scarcity issue in the Loess Plateau. Copyright © 2017. Published by Elsevier B.V.

  11. Evolutionary diversifications of plants on the Qinghai-Tibetan Plateau

    Science.gov (United States)

    Wen, Jun; Zhang, Jian-Qiang; Nie, Ze-Long; Zhong, Yang; Sun, Hang

    2014-01-01

    The Qinghai-Tibetan Plateau (QTP) is the highest and one of the most extensive plateaus in the world. Phylogenetic, phylogeographic, and ecological studies support plant diversifications on the QTP through multiple mechanisms such as allopatric speciation via geographic isolation, climatic oscillations and divergences, pollinator-mediated isolation, diploid hybridization and introgression, and allopolyploidy. These mechanisms have driven spectacular radiations and/or species diversifications in various groups of plants such as Pedicularis L., Saussurea DC., Rhododendron L., Primula L., Meconopsis Vig., Rhodiola L., and many lineages of gymnosperms. Nevertheless, much work is needed toward understanding the evolutionary mechanisms of plant diversifications on the QTP. Well-sampled biogeographic analyses of the QTP plants in the broad framework of the Northern Hemisphere as well as the Southern Hemisphere are still relatively few and should be encouraged in the next decade. This paper reviews recent evidence from phylogenetic and biogeographic studies in plants, in the context of rapid radiations, mechanisms of species diversifications on the QTP, and the biogeographic significance of the QTP in the broader context of both the Northern and Southern Hemisphere biogeography. Integrative multidimensional analyses of phylogeny, morphological innovations, geography, ecology, development, species interactions and diversifications, and geology are needed and should shed insights into the patterns of evolutionary assembly and radiations in this fascinating region. PMID:24575120

  12. Land surface changes enhanced drought over the Loess Plateau

    Science.gov (United States)

    Xu, Xianli; Liu, Meixian

    2017-04-01

    In order to prevent the severe soil-water erosion over the Loess Plateau (LP), the Chinese Government initiated large scale ecological restoration (ER) in the past half century. The ER had successfully reduced soil erosion however also changed the land surface and altered the regional water-energy balance and consequently the dryness/wetness conditions, which in turn affects the vegetation. Knowledge of the impacts of the ER on dryness/wetness conditions is essential for developing future effective ER measures. For this purpose, a new drought index, the standardized wetness index (SWI), was proposed. The SWI can represent the dryness/wetness brought by solely climate change (denoted as SWIf in this case), and the dryness/wetness brought by the joint effects of climate change and land surface change (SWI_m). A total of 13 main catchments were selected to investigate the effects of ER on dryness/wetness conditions during 1961-2009 over LP. Results showed that the overall increasing parameter n (a parameter of the Budyko formulae) could be well explained by the ER measures (R^2=1) in these catchments. The SWIf and SWIm had similar fluctuating features and exhibited downward trends. However, the SWIm had larger negative trends than the SWI_f, implying that ER actions enhanced the drought conditions over the drying LP in the past decades. Therefore, we suggest that the government should manage and maintain the existing achievements but not further expand revegetation because of unintended consequences on drought vulnerability.

  13. Early villages and prehistoric sites in the Abharroud Basin, northwest of the Iranian Central Plateau

    Directory of Open Access Journals (Sweden)

    Sajjad Alibaigi

    2012-12-01

    Full Text Available The Abharroud basin is an important region in archaeological studies of the northwestern outskirts of the central plateau, and the west and northwest of Iran. Considering its environmental capabilities and geographical location, studying the region can leads us to a better understanding of regional relations and also inter-regional interaction between the cultural-geographical regions. During the two seasons of archaeological survey, 257 archaeological sites were discovered, dating from the lower Palaeolithic to recent ages. Of these, 34 sites contained prehistoric remains. Most of the identified sites are the remains of scattered villages and seasonal camps in different areas of the basin, on the plain and also impassable heights.

  14. Climatic Changes on Tibetan Plateau Based on Ice Core Records

    Science.gov (United States)

    Yao, T.

    2008-12-01

    Climatic changes have been reconstructed for the Tibetan Plateau based on ice core records. The Guliya ice core on the Tibetan Plateau presents climatic changes in the past 100,000 years, thus is comparative with that from Vostok ice core in Antarctica and GISP2 record in Arctic. These three records share an important common feature, i.e., our climate is not stable. It is also evident that the major patterns of climatic changes are similar on the earth. Why does climatic change over the earth follow a same pattern? It might be attributed to solar radiation. We found that the cold periods correspond to low insolation periods, and warm periods to high insolation periods. We found abrupt climatic change in the ice core climatic records, which presented dramatic temperature variation of as much as 10 °C in 50 or 60 years. Our major challenge in the study of both climate and environment is that greenhouse gases such as CO2, CH4 are possibly amplifying global warming, though at what degree remains unclear. One of the ways to understand the role of greenhouse gases is to reconstruct the past greenhouse gases recorded in ice. In 1997, we drilled an ice core from 7100 m a.s.l. in the Himalayas to reconstruct methane record. Based on the record, we found seasonal cycles in methane variation. In particular, the methane concentration is high in summer, suggestiing active methane emission from wet land in summer. Based on the seasonal cycle, we can reconstruct the methane fluctuation history in the past 500 years. The most prominent feature of the methane record in the Himalayan ice core is the abrupt increase since 1850 A.D.. This is closely related to the industrial revolution worldwide. We can also observe sudden decrease in methane concentration during the World War I and World War II. It implies that the industrial revolution has dominated the atmospheric greenhouse gas emission for about 100 years. Besides, the average methane concentration in the Himalayan ice core is

  15. Climate change and its impacts on vegetation distribution and net primary productivity of the alpine ecosystem in the Qinghai-Tibetan Plateau.

    Science.gov (United States)

    Gao, Qingzhu; Guo, Yaqi; Xu, Hongmei; Ganjurjav, Hasbagen; Li, Yue; Wan, Yunfan; Qin, Xiaobo; Ma, Xin; Liu, Shuo

    2016-06-01

    Changes in climate have caused impacts on ecosystems on all continents scale, and climate change is also projected to be a stressor on most ecosystems even at the rate of low- to medium-range warming scenarios. Alpine ecosystem in the Qinghai-Tibetan Plateau is vulnerable to climate change. To quantify the climate change impacts on alpine ecosystems, we simulated the vegetation distribution and net primary production in the Qinghai-Tibetan Plateau for three future periods (2020s, 2050s and 2080s) using climate projection for RCPs (Representative Concentration Pathways) RCP4.5 and RCP8.5 scenarios. The modified Lund-Potsdam-Jena Dynamic Global Vegetation Model (LPJ model) was parameter and test to make it applicable to the Qinghai-Tibetan Plateau. Climate projections that were applied to LPJ model in the Qinghai-Tibetan Plateau showed trends toward warmer and wetter conditions. Results based on climate projections indicated changes from 1.3°C to 4.2°C in annual temperature and changes from 2% to 5% in annual precipitation. The main impacts on vegetation distribution was increase in the area of forests and shrubs, decrease in alpine meadows which mainly replaced by shrubs which dominated the eastern plateau, and expanding in alpine steppes to the northwest dominated the western and northern plateau. The NPP was projected to increase by 79% and 134% under the RCP4.5 and RCP8.5. The projected NPP generally increased about 200gC·m(-2)·yr(-1) in most parts of the plateau with a gradual increase from the eastern to the western region of the Qinghai-Tibetan Plateau at the end of this century. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Soil Nitrogen Storage, Distribution, and Associated Controlling Factors in the Northeast Tibetan Plateau Shrublands

    Directory of Open Access Journals (Sweden)

    Xiuqing Nie

    2017-11-01

    Full Text Available Although the soils in the Tibetan Plateau shrublands store large amounts of total nitrogen (N, the estimated values remain uncertain because of spatial heterogeneity and a lack of field observations. In this study, we quantified the regional soil N storage, spatial and vertical density distributions, and related climatic controls using 183 soil profiles sampled from 61 sites across the Northeast Tibetan Plateau shrublands during the period of 2011–2013. Our analysis revealed a soil N storage value of 132.40 Tg at a depth of 100 cm, with an average density of 1.21 kg m−2. Soil N density was distributed at greater levels in alpine shrublands, compared with desert shrublands. Spatially, soil N densities decreased from south to north and from east to west, and, vertically, the soil N in the upper 30 and 50 cm accounted for 42% and 64% of the total soil N stocks in the Tibetan Plateau. However, compared with desert shrublands, the surface layers in alpine shrublands exhibited a larger distribution of soil N stocks. Overall, the soil N density in the top 30 cm increased significantly with the mean annual precipitation (MAP and tended to decrease with the mean annual temperature (MAT, although the dominant climatic controls differed among shrubland types. Specifically, MAP in alpine shrublands, and MAT in desert shrubland, had a weak effect on N density. Soil pH can significant affect soil N density in the Tibetan Plateau shrublands. In conclusion, changes in soil N density should be monitored over the long term to provide accurate information about the effects of climatic factors.

  17. Taos Plateau Volcanic Project: A Vehicle for Integration of Concepts in Igneous Petrology

    Science.gov (United States)

    Henry, D.; Dutrow, B.

    2003-12-01

    Integrating concepts of igneous petrology is generally a challenge, but can be effective in the context of a project based on actual field, geochemical and geochronological data. The final lab project in the igneous portion of petrology involves a series of volcanic and associated rock samples that were collected from the Taos Plateau Volcanic Field, New Mexico, USA. Samples were collected over an area of several tens of km2 throughout the Plateau and represent a spatially and temporally correlated rock suite related to continental rifting. Rift-related magmatism encompasses much of the diversity of terrestrial magma types. Compositions of mafic magmas range from tholeiite to some of the most silica-undersaturated magmas found on the continents. Large effusive eruptions from fissures are typical of some rifts, whereas others may be dominated by central vent cones or even silicic caldera complexes. The injection of mantle-derived magma in extending crust may have a profound effect on the rheology of the crust and, therefore, the style of deformation associated with extension. Most of these aspects of rift volcanism and a wide range of mafic to silicic magma compositions are represented in the Rio Grande rift and the volcanic rocks of the Taos Plateau. In addition, much published data exists for whole rock and trace element geochemistry as well as geochronology. Rock samples and associated information are presented so that the student must integrate multiple lines of evidence, petrographic, petrologic, geochemical and geochronological data in a geospatial framework, to establish a geologic history of the region. The student must also draw on skills learned in mineralogy and structural geology furthering core geoscience education. Subsequent to the petrology course, the students visit the Taos Plateau Volcanic Field during their required field camp, thus reinforcing the linkage between the classroom setting and geologic reality.

  18. Adjusting the M8 algorithm to earthquake prediction in the Iranian plateau

    Science.gov (United States)

    Mojarab, Masoud; Memarian, Hossein; Zare, Mehdi; Kossobokov, Vladimir

    2017-07-01

    Earthquake prediction is one of the challenging problems of seismology. The present study intended to setup a routine prediction of major earthquakes in the Iranian plateau using a modification of the intermediate-term middle-range algorithm M8, in which original version has demonstrated high performance in a real-time Global Test over the last two decades. An investigation of earthquake catalog covering the entire the Iranian plateau through 2012 has shown that a modification of the M8 algorithm, adjusted for a rather low level of earthquake occurrence reported in the region, is capable for targeting magnitude 7.5+ events. The occurrence of the April 16, 2013, M7.7 Saravan and the September 24, 2013, M7.7 Awaran earthquakes at the time of writing this paper (14 months before Saravan earthquake occurrence) confirmed the results of investigation and demonstrated the need for further studies in this region. Earlier tests, M8 application in all over the Iran, showed that the 2013 Saravan and Awaran earthquakes may precede a great earthquake with magnitude 8+ in Makran region. To verify this statement, the algorithm M8 was applied once again on an updated catalog to September 2013. The result indicated that although the study region recently experienced two magnitude 7.5+ earthquakes, it remains prone to a major earthquake. The present study confirms the applicability of M8 algorithm for predicting earthquakes in the Iranian plateau and establishes an opportunity for a routine monitoring of seismic activity aimed at prediction of the largest earthquakes that can play a significant role in mitigation of damages due to natural hazard.

  19. Ti-bearing aenigmatite from Djinga Tadorgal (Adamawa plateau ...

    African Journals Online (AJOL)

    Ti-bearing aenigmatite from Djinga Tadorgal (Adamawa plateau) and Sao Tomé (Cameroon Line) phonolites: geochemical implications and application of the QUILF thermobarometer for the crystallization conditions.

  20. Coccidioidomycosis in Chicken Pullets in Jos, Plateau State, Nigeria ...

    African Journals Online (AJOL)

    Coccidioidomycosis in Chicken Pullets in Jos, Plateau State, Nigeria: A Case Report. AR Jambalang, IN Ogo, JO Ibu, M Gisilanbe, W Bertu, L Jwander, B Benjamin, S Chukwukere, Y Nasir, N Sanda, A Benshak, GOA Agada, M Kubo ...

  1. Surface Wave Attenuation in the Tibetan Plateau from Ambient Noise

    Science.gov (United States)

    2015-08-31

    AFRL-RV-PS- TR-2015-0150 AFRL-RV-PS- TR-2015-0150 SURFACE WAVE ATTENUATION IN THE TIBETAN PLATEAU FROM AMBIENT NOISE University of Illinois at...DATES COVERED (From - To) 01 May 2012 to 31 Aug 2015 4. TITLE AND SUBTITLE Surface Wave Attenuation in the Tibetan Plateau from Ambient Noise 5a...extract amplitude information from the empirical Green functions (EGF) derived from ambient noise correlations and to map the attenuation of the

  2. Return to sport following tibial plateau fractures: A systematic review

    OpenAIRE

    Robertson, Greg A J; Wong, Seng J; Wood, Alexander M.

    2017-01-01

    AIM To systemically review all studies reporting return to sport following tibial plateau fracture, in order to provide information on return rates and times to sport, and to assess variations in sporting outcome for different treatment methods. METHODS A systematic search of CINAHAL, Cochrane, EMBASE, Google Scholar, MEDLINE, PEDro, Scopus, SPORTDiscus and Web of Science was performed in January 2017 using the keywords ?tibial?, ?plateau?, ?fractures?, ?knee?, ?athletes?, ?sports?, ?non-oper...

  3. The burying and grazing effects of plateau pika on alpine grassland are small: a pilot study in a semiarid basin on the Qinghai-Tibet Plateau

    Directory of Open Access Journals (Sweden)

    S. Yi

    2016-11-01

    Full Text Available There is considerable controversy about the effects of plateau pika (Ochotona curzoniae, hereafter pika on alpine grassland on the Qinghai-Tibet Plateau (QTP. On the one hand, pika is considered a keystone species. On the other hand, it is being poisoned. Although significant efforts have been made to study the effects of pika at a quadrat scale ( ∼  m2, our knowledge about its distribution and effects at a larger scale is very limited. In this study, we investigated the direct effects, i.e., burying and grazing, of pika by upscaling field sampling at a quadrat scale to a plot scale ( ∼  1000 m2 by aerial photographing. Altogether 168 plots were set on four different types of alpine grassland in a semiarid basin on the QTP. Results showed that (1 the effects of pika pile burying on the reduction of vegetation cover, biomass, soil carbon, and nitrogen were less than 10 %, which was much smaller than the effects of bald patches; and (2 pika consumed 8–21 % of annual net primary production of grassland. We concluded that the direct burying and grazing effects of pika on alpine grassland were minor in this region. The quadcopter is an efficient and economic tool for long-term repeated monitoring over large regions for further understanding the role of pika.

  4. Reworked loess and Yellow River sediment as the main sources of the Chinese Loess Plateau

    Science.gov (United States)

    Licht, Alexis; Pullen, Alex; Kapp, Paul; Abell, jordan; Giesler, Dominique

    2016-04-01

    The Quaternary aeolian dust deposits of the Chinese Loess Plateau have been attributed to spring and winter monsoonal storms sweeping clastic material from the deserts of the Asian interior into central China. Recent U-Pb geochronological studies of aeolian zircons have emphasized the existence of two major wind pathways: from the north, throughout the Tengger, and Mu Us deserts during interglacials, and from the west, through the Qaidam Basin during glacials. Others have emphasized the importance of Yellow River supply in the Loess Plateau sediment budget. However, tracking dust source regions through U-Pb dating is particularly complex, given the paucity of data in many potential sources regions and the similar ages peak in the age probability distributions of western and Northern deserts in central China. Here, we present an extended dataset of U-Pb ages covering all the potential provenance areas for the aeolian dust in central Asia and including 2400 new ages from loess, paleosols, modern sand dunes and fluvial deposits. We then propose a new mixture modeling technique to statistically address the contribution of these different sources to the Loess Plateau sedimentary budget. Our contribution estimates indicate that aeolian supply is dominated (60-70 %) by reworking of Yellow River sediment. Moreover, evidence of Qaidam Basin sourced zircons (15-20 %) in both loess (glacial) and paleosols (interglacial) layers corroborates the existence of an erosive wind pathway from the west during glacials and implies that a substantial portion of the interglacial dust is recycled from older glacial loess. We propose that sediment reworking of Yellow River sediment and older loesses by wind homogenizes aeolian zircon populations on the Chinese Loess Plateau toward a glacial provenance due to higher dust accumulation rates during glacials. These findings indicate that the Loess Plateau has evolved as a more dynamic landform than previous thought where wind deflation

  5. Investigations of the gravity profile below the Tibetan plateau

    Science.gov (United States)

    Shen, W. B.; Han, J. C.

    2012-04-01

    Scientists pay great attention to the structure and dynamics of the Tibetan plateau due to the fact that it is a natural experiment site for geoscience studies. The gravity profiles below the Tibetan plateau with successive high-accuracy play more and more significant role in studying the structure and evolution of the Tibetan plateau. This study focuses on determining the inner gravity field of the Tibetan plateau until to the depth of D and interpret possible mechanism of the gravity profile below the Tibetan plateau, especially reinvestigating the isostasy problem (Pratt hypothesis and Airy hypothesis). The inner gravity field below the Tibetan plateau is determined based on a simple technique (i.e. a combination of Newtonian integral, downward continuation of gravity field, and "remove-restore" scheme) and the following datasets: the external Earth gravitational model EGM2008 and the digital topographic model DTM2006.0 released by NGA (National Geospatial-Intelligence Agency, USA), and the crust density distribution model CRUST2.0 released by NGS (National Geological Survey, USA). This study is supported by Natural Science Foundation China (grant No.40974015; No.41174011).

  6. Environmental analysis report for Le Plateau SRI Wind Energy Centre's Le Plateau wind turbine array project on Ruisseau-Ferguson non-organized territory; Rapport d'analyse environnementale pour le projet de parc eolien Le Plateau sur le territoire non organise de Ruisseau-Ferguson par le Centre d'energie eolienne Le Plateau SRI

    Energy Technology Data Exchange (ETDEWEB)

    Messely, L.; Theberge, M.C.; Blouin, C.; Roberge, R.

    2009-10-28

    Hydro-Quebec Distribution (HQ-D) has retained Le Plateau SRI Wind Energy Centre to construct a 2000 MW wind turbine array in the Avignon county in the Gaspe region, more specifically on the territory of Ruisseau-Ferguson. The territory consists primarily of public land and private territory under forest trust. The proposed project involves the construction of 60 wind turbines with a total installed capacity of 138.6 MW. An environmental impact study was conducted to evaluate the visual impact, the noise levels as well as the local and regional economical implications of the project. A follow-up study will be conducted once the project is completed to determine the impact on migratory birds and bats, particularly in terms of nesting periods. Le Plateau SRI Wind Energy Centre requires that 51 per cent of the costs of the project be invested in the region. HQ-D requires that 30 per cent of turbine costs be invested in the region. The project was approved in view of Quebec's new energy bill that promotes clean and renewable power. The environmental plan was also approved provided that certain conditions are met. 28 refs., 2 figs.

  7. Intercropping competition between apple trees and crops in agroforestry systems on the Loess Plateau of China.

    Science.gov (United States)

    Gao, Lubo; Xu, Huasen; Bi, Huaxing; Xi, Weimin; Bao, Biao; Wang, Xiaoyan; Bi, Chao; Chang, Yifang

    2013-01-01

    Agroforestry has been widely practiced in the Loess Plateau region of China because of its prominent effects in reducing soil and water losses, improving land-use efficiency and increasing economic returns. However, the agroforestry practices may lead to competition between crops and trees for underground soil moisture and nutrients, and the trees on the canopy layer may also lead to shortage of light for crops. In order to minimize interspecific competition and maximize the benefits of tree-based intercropping systems, we studied photosynthesis, growth and yield of soybean (Glycine max L. Merr.) and peanut (Arachis hypogaea L.) by measuring photosynthetically active radiation, net photosynthetic rate, soil moisture and soil nutrients in a plantation of apple (Malus pumila M.) at a spacing of 4 m × 5 m on the Loess Plateau of China. The results showed that for both intercropping systems in the study region, soil moisture was the primary factor affecting the crop yields followed by light. Deficiency of the soil nutrients also had a significant impact on crop yields. Compared with soybean, peanut was more suitable for intercropping with apple trees to obtain economic benefits in the region. We concluded that apple-soybean and apple-peanut intercropping systems can be practical and beneficial in the region. However, the distance between crops and tree rows should be adjusted to minimize interspecies competition. Agronomic measures such as regular canopy pruning, root barriers, additional irrigation and fertilization also should be applied in the intercropping systems.

  8. Results of Gravity Observations Using a Superconducting Gravimeter at the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Heping Sun

    2013-01-01

    Full Text Available The tidal and nontidal gravity change characteristics in the Tibetan Plateau region were investigated using the continuous gravity measurements recorded with a superconducting gravimeter (SG installed in Lhasa from December 8, 2009 to September 30, 2011. The results indicated that the precision of the tidal gravity observations with the SG in Lhasa was very high. The standard deviation of the harmonic analysis for the gravity tides was 0.498 nm s-2, and the uncertainties of amplitude factors in the four main tidal waves (i.e., O1, K1, M2 and S2 were better than 0.002%. In addition, the diurnal gravity tide observations clearly revealed a pattern of nearly diurnal resonance. As a result, it is affirmed that the station should act as a local tidal gravity reference in the Tibetan Plateau and its adjacent regions. The load effects of oceanic tides are so weak that the resulting perturbation in the gravimetric factors is less than 0.6%. However, the load effects of the local atmosphere on either the tidal or the nontidal gravity observations are significant, although no seasonal variations have been found. After removing the atmospheric effects, the standard deviation of the harmonic analysis for the gravity tides decreased obviously from 4.160 to 0.498 nm s-2. Having removed the load effects of oceanic tides and local atmosphere, it is found that the tidal gravity observations are significantly different from those expected theoretically, which may be related to active tectonic movement and extremely thick crust in the Tibetan Plateau region. In addition, the Earth¡¦s free oscillations excited by 2011 Tohoku-Oki Mw 9.0 Earthquake were successfully detected.

  9. Paleolithic Y-haplogroup heritage predominates in a Cretan highland plateau.

    Science.gov (United States)

    Martinez, Laisel; Underhill, Peter A; Zhivotovsky, Lev A; Gayden, Tenzin; Moschonas, Nicholas K; Chow, Cheryl-Emiliane T; Conti, Simon; Mamolini, Elisabetta; Cavalli-Sforza, L Luca; Herrera, Rene J

    2007-04-01

    The island of Crete, credited by some historical scholars as a central crucible of western civilization, has been under continuous archeological investigation since the second half of the nineteenth century. In the present work, the geographic stratification of the contemporary Cretan Y-chromosome gene pool was assessed by high-resolution haplotyping to investigate the potential imprints of past colonization episodes and the population substructure. In addition to analyzing the possible geographic origins of Y-chromosome lineages in relatively accessible areas of the island, this study includes samples from the isolated interior of the Lasithi Plateau--a mountain plain located in eastern Crete. The potential significance of the results from the latter region is underscored by the possibility that this region was used as a Minoan refugium. Comparisons of Y-haplogroup frequencies among three Cretan populations as well as with published data from additional Mediterranean locations revealed significant differences in the frequency distributions of Y-chromosome haplogroups within the island. The most outstanding differences were observed in haplogroups J2 and R1, with the predominance of haplogroup R lineages in the Lasithi Plateau and of haplogroup J lineages in the more accessible regions of the island. Y-STR-based analyses demonstrated the close affinity that R1a1 chromosomes from the Lasithi Plateau shared with those from the Balkans, but not with those from lowland eastern Crete. In contrast, Cretan R1b microsatellite-defined haplotypes displayed more resemblance to those from Northeast Italy than to those from Turkey and the Balkans.

  10. Proposed biodiversity conservation areas: gap analysis and spatial prioritization on the inadequately studied Qinghai Plateau, China

    Directory of Open Access Journals (Sweden)

    Renqiang Li

    2018-01-01

    Full Text Available Global biodiversity priorities are primarily addressed through the establishment or expansion of conservation areas (CAs. Spatial prioritization of these CAs can help minimize biodiversity loss by accounting for the uneven distribution of biodiversity and conservation considerations (e.g., accessibility, cost, and biodiversity threats. Furthermore, optimized spatial priorities can help facilitate the judicious use of limited conservation resources by identifying cost effective CA designs. Here, we demonstrate how key species and ecosystems can be incorporated into systematic conservation planning to propose the expansion and addition of new CAs in the biodiversity-unique and data-poor region of Qinghai Plateau, China. We combined species distribution models with a systematic conservation planning tool, MARXAN to identify CAs for biodiversity on Qinghai Plateau. A set of 57 optimal CAs (273,872 km2, 39.3 % of this Province were required to achieve the defined conservation targets in Qinghai Province. We also identified 29 new CAs (139,216 km2, 20% of Qinghai Province outside the existing nature reserve (NRs that are necessary to fully achieve the proposed conservation targets. The conservation importance of these 29 new CAs was also indicated, with 10 labeled as high priority, 11 as medium priority, and 8 as low priority. High priority areas were more abundant in the eastern and southeastern parts of this region. Our results suggest that many species remain inadequately protected within the Qinghai Plateau, with conservation gaps in eastern and northwestern regions. The proposed more representative and effective CAs can provide useful information for adjusting the existing NRs and developing the first National Park in China.

  11. Widespread Neogene and Quaternary Volcanism on Central Kerguelen Plateau, Southern Indian Ocean

    Science.gov (United States)

    Duncan, R. A.; Falloon, T.; Quilty, P. G.; Coffin, M. F.

    2016-12-01

    We report new age determinations and compositions for rocks from 18 dredge hauls collected from eight submarine areas across Central Kerguelen Plateau (CKP). Sea knolls and volcanic fields with multiple small cones were targeted over a 125,000 km2 region that includes Heard and McDonald islands. Large early Miocene (16-22 Ma) sea knolls rise from the western margin of the CKP and are part of a NNW-SSE line of volcanic centers that lie between Îles Kerguelen and Heard and McDonald islands. A second group of large sea knolls is aligned E-W across the center of this region. We see evidence of much younger activity (5 Ma to present) in volcanic fields to the north of, and up to 300 km NE of Heard Island. Compositions include basanite, basalt, and trachybasalt, that are broadly similar to plateau lava flows from nearby Ocean Drilling Program (ODP) Site 1138, lower Miocene lavas at Îles Kerguelen, dredged rocks from the early Miocene sea knolls, and Big Ben lavas from Heard Island. Geochemical data indicate decreasing fractions of mantle source melting with time. The western line of sea knolls has been related to hotspot activity now underlying the Heard Island area. In view of the now recognized much larger area of young volcanic activity, we propose that a broad region of CKP became volcanically active in Neogene time due to incubation of plume material at the base of the relatively stationary overlying plateau. The presence of pre-existing crustal faults promotes access for melts from the Heard mantle plume to rise to the surface.

  12. A retrospective study of tibial plateau translation following tibial plateau levelling osteotomy stabilisation using three different plate types.

    Science.gov (United States)

    Woodbridge, N; Corr, S A; Grierson, J; Arthurs, G

    2011-01-01

    To retrospectively evaluate mediolateral translation of the proximal tibial segment (tibial plateau) after tibial plateau levelling osteotomy (TPLO), stabilised with three types of plate. Pre- and postoperative radiographs of 79 dogs that had TPLO surgery using three different types of plates were reviewed. Two plate types incorporated non-locking screws: Slocum (22 cases) and Orthomed Delta (33 cases) plates. The third plate type incorporated locking screws: Synthes TPLO Locking Compression Plate (LCP) (24 cases). The radiographs were viewed by three Diplomate surgeons who were blinded to the type of implant used. Medial or lateral translation of the proximal tibial plateau relative to the tibial diaphysis was assessed and measured at the lateral tibial cortex at the osteotomy site. Mean lateral translation of the tibial plateau was significantly greater when using the Synthes TPLO LCP with locking screws (+2.1 mm) compared to the non-locking Slocum (+0.4 mm) or Orthomed Delta (0.0 mm) plates. The use of the Synthes TPLO LCP will maintain a malalignment of the tibial plateau. Accurate alignment of the tibial plateau must be ensured prior to application of the Synthes TPLO LCP.

  13. The Change in the area of various land covers on the Tibetan Plateau during 1957-2015

    Science.gov (United States)

    Cuo, Lan; Zhang, Yongxin

    2017-04-01

    With average elevation of 4000 m and area of 2.5×106 km2, Tibetan Plateau hosts various fragile ecosystems such as perennial alpine meadow, perennial alpine steppe, temperate evergreen needleleaf trees, temperate deciduous trees, temperate shrub grassland, and barely vegetated desert. Perennial alpine meadow and steppe are the two dominant vegetation types on the heartland of the plateau. MODIS Leaf Area Index (LAI) ranges from 0 to 2 in most part of the plateau. With climate change, these ecosystems are expected to undergo alteration. This study uses a dynamic vegetation model - Lund-Potsdam-Jena (LPJ) to investigate the change of the barely vegetated area and other vegetation types caused by climate change during 1957-2015 on the Tibetan Plateau. Model simulated foliage projective coverage (FPC) and plant functional types (PFTs) are selected for the investigation. The model is evaluated first using both field surveyed land cover map and MODIS LAI images. Long term trends of vegetation FPC is examined. Decadal variations of vegetated and barely vegetated land are compared. The impacts of extreme precipitation, air temperature and CO2 on the expansion and contraction of barely vegetated and vegetated areas are shown. The study will identify the dominant climate factors in affecting the desert area in the region.

  14. Zero temperature non-plateau magnetization and magnetocaloric effect in an Ising-XYZ diamond chain structure

    Energy Technology Data Exchange (ETDEWEB)

    Torrico, J. [Instituto de Fisica, Universidade Federal de Alagoas, 57072-970, Maceió, AL (Brazil); Rojas, M.; Souza, S.M. de [Departamento de Fisica, Universidade Federal de Lavras, 37200-000, Lavras, MG (Brazil); Rojas, Onofre, E-mail: ors@dfi.ufla.br [Departamento de Fisica, Universidade Federal de Lavras, 37200-000, Lavras, MG (Brazil)

    2016-10-23

    Zero temperature non-plateau magnetization is a peculiar property of a quantum spin chain and it sometimes appears due to different gyromagnetic factors. In this study, we illustrate a quite unusual non-plateau magnetization property driven by XY-anisotropy in an Ising-XYZ diamond chain. Two particles with spin-1/2 are bonded by XYZ coupling and they are responsible for the emergence of non-plateau magnetization. These two quantum operator spins are bonded to two nodal Ising spins and this process is repeated infinitely to yield a diamond chain structure. Due to the non-plateau magnetization property, we focus our discussion on the magnetocaloric effect of this model by presenting the isentropic curves and the Grüneisen parameters, as well as showing the regions where the model exhibits an efficient magnetocaloric effect. Due to the existence of two phases located very close to each other, the strong XY-anisotropy exhibits a particular behavior with a magnetocaloric effect, with a wider interval in the magnetic field, where the magnetocaloric effect is efficient.

  15. Earliest tea as evidence for one branch of the Silk Road across the Tibetan Plateau

    Science.gov (United States)

    Lu, Houyuan; Zhang, Jianping; Yang, Yimin; Yang, Xiaoyan; Xu, Baiqing; Yang, Wuzhan; Tong, Tao; Jin, Shubo; Shen, Caiming; Rao, Huiyun; Li, Xingguo; Lu, Hongliang; Fuller, Dorian Q.; Wang, Luo; Wang, Can; Xu, Deke; Wu, Naiqin

    2016-01-01

    Phytoliths and biomolecular components extracted from ancient plant remains from Chang’an (Xi’an, the city where the Silk Road begins) and Ngari (Ali) in western Tibet, China, show that the tea was grown 2100 years ago to cater for the drinking habits of the Western Han Dynasty (207BCE-9CE), and then carried toward central Asia by ca.200CE, several hundred years earlier than previously recorded. The earliest physical evidence of tea from both the Chang’an and Ngari regions suggests that a branch of the Silk Road across the Tibetan Plateau, was established by the second to third century CE.

  16. THE SOMEŞAN PLATEAU LAKES: GENESIS, EVOLUTION AND TERRITORIAL REPARTITION

    OpenAIRE

    Victor SOROCOVSCHI; Gheorghe ŞERBAN

    2010-01-01

    The present paper analyzes the genesis of the lake depressions in the Someşan Plateau and the way they evolved in time and space, as well as the morphometric elements characteristic of the different genetic types of lakes. The natural lakes in this region are few and their dimensions are small; they generally appear solitarily and only rarely as lake complexes. In this category have been included the valley lakes, the lakes formed in abandoned meanders and the lakes formed in areas with lands...

  17. Biomass burning and urban air pollution over the Central Mexican Plateau

    Directory of Open Access Journals (Sweden)

    P. O. Wennberg

    2009-07-01

    Full Text Available Observations during the 2006 dry season of highly elevated concentrations of cyanides in the atmosphere above Mexico City (MC and the surrounding plains demonstrate that biomass burning (BB significantly impacted air quality in the region. We find that during the period of our measurements, fires contribute more than half of the organic aerosol mass and submicron aerosol scattering, and one third of the enhancement in benzene, reactive nitrogen, and carbon monoxide in the outflow from the plateau. The combination of biomass burning and anthropogenic emissions will affect ozone chemistry in the MC outflow.

  18. Topographic Analyses of the Vestalia Terra plateau, Vesta (Invited)

    Science.gov (United States)

    Buczkowski, D.; Wyrick, D. Y.; Williams, D. A.; Preusker, F.; Roatsch, T.; DeSanctis, M. C.; Raymond, C. A.; Russell, C. T.

    2013-12-01

    The identification of Vestalia Terra, a topographically high region of Vesta bound by steep scarps, is itself a direct result of topographic analysis of the asteroid. However, additional analysis of the topography of the plateau has yielded important scientific discoveries. While most equatorial regions on Vesta display numerous wide and flat-floored troughs, Vestalia Terra does not. There are, however, three long pit crater chains on top of the plateau that are roughly aligned with the equatorial flat-floor troughs. Pit crater chains are a type of feature that have been observed on several planetary bodies and have been described as lines of circular to elliptical depressions which lack an elevated rim, ejecta deposits, or lava flows. Individual pits most commonly have a conical shape, sometimes with a flat floor, but in some cases they are elliptical in shape, with the long axis parallel to the chain orientation. Pit craters can in many cases coalesce into linear troughs, but the pits are often bordered by a graben (a down-dropped block bounded by normal faults) even before this coalesence. While pits are generally agreed to have formed by collapse into a subsurface cavity, the exact formation mechanisms hypothesized can vary from planet to planet. However, several researchers have suggested that pit crater chains on small bodies such as Phobos, Eros, Lutetia and Enceladus are formed by the drainage of a loose cover material into subsurface voids formed by dilation of a subsurface normal fault, a method described in extensive detail for pit crater chains on Mars. This formation hypothesis is strengthened by the strong correlation between pit crater chains and fault-bounded graben that has been observed and by the fact that pit chains are often in alignment with a regional fault and fracture system. There are two fundamental controls on the maximum size a pit can attain: the thickness of the overlying regolith and the amount of subsurface accommodation space. The

  19. Soil temperature change on the Tibetan Plateau

    Science.gov (United States)

    Zhu, F.; Cuo, L.; Zhang, Y.; Luo, J. J.

    2015-12-01

    Increased radiative forcing has resulted in the global warming that includes the warming in air and soil over the past decades. The warming at the Earth's surface propagates or conducts downward into the ground and modifies the ambient ground thermal regime. In addition to the surface radiation that directly heats the soil, the other soil heat fluxes associated with atmospheric circulations of various scales are important mechanisms as well. The quantification of the causal relationships between the radiation, large scale atmospheric circulations and soil temperature change in the upper few meters on the Tibetan Plateau (TP) is the objective of this study. Daily soil temperature data during 1980-2013 at various depths from surface down to 3.2 m depth at 88 stations located on the TP obtained from China Meteorological Administration are used to investigate the changes in soil temperature. After the quality control, the Mann-Kendall trend, EOF and regression analyses are applied to analyze the soil temperature and radiation data. The Mann-Kendall test shows that soil temperature at layers above 3.2-m-depth increases from 1980 to 2013 at most stations on the TP, although the warming rate varies among stations. Time series of the EOF analysis shows that a hiatus in the soil temperature warming has occurred since 2004 on the TP, which is several years behind the hiatus of the global warming but is similar to the air temperature change on the TP. Besides, we do not find a clear phase delay from the surface to the 3.2m level. Net surface solar radiation, long wave radiation that partly reflects the greenhouse gases forcing, latent and sensible heat fluxes are examined to understand the underlying mechanisms for the distinct warming of the soil on the TP. Contributions of the atmospheric circulation changes, induced by either internal variability or external forcing or both of the two factors, are also examined. The above analysis results will be presented at the

  20. Extended Anterolateral Approach for Complex Lateral Tibial Plateau Fractures.

    Science.gov (United States)

    Kfuri, Mauricio; Schatzker, Joseph; Castiglia, Marcello Teixeira; Giordano, Vincenzo; Fogagnolo, Fabricio; Stannard, James P

    2017-03-01

    Complex fractures of the lateral tibial plateau may extend to the posterior rim of the knee and to the tibial spines. Displaced fractures of the posterolateral corner of the tibial plateau may result in joint incongruity and instability, especially with the knee in flexion. Anatomical reduction of the joint surface and containment of the tibial rim are the primary goals of the treatment in such cases. Dedicated surgical approaches including dissection of the peroneal nerve, sometimes in association with an osteotomy of the fibular head are typically used to address these injuries. Some techniques require special positioning of the patient on the operative table. Anatomical studies of the knee allowed us to conclude that an osteotomy of the lateral epicondyle of the femur may be a natural extension of the standard anterolateral approach to the tibial plateau. The main advantage of this approach is the broad exposure of the lateral joint surface, allowing its anatomical reduction. It does not violate the proximal tibiofibular joint or pose a risk to the peroneal nerve. The main limitation is the lack of visualization of the posterior metaphysis of the tibia, preventing the application of a buttress plate parallel to the plane of fracture split. To overcome this limitation, we describe a method to support the posterior tibial plateau rim, in cases of bicondylar tibial plateau fractures, combining the extended anterolateral with the posteromedial approach. For selected cases, with a significant compromise of the posterolateral and anterolateral quadrants of the tibial plateau, including the tibial spines, the extended anterolateral approach may be complemented by a planned detachment of the anterior horn of the lateral meniscus. In such variant, a complete exposure of the entire surface of the lateral tibial plateau and tibial spines is achievable, assuring optimal conditions for an anatomical reduction of the articular surface. Thieme Medical Publishers 333 Seventh

  1. Intraseasonal variability of winter precipitation over central asia and the western tibetan plateau from 1979 to 2013 and its relationship with the North Atlantic Oscillation

    Science.gov (United States)

    Liu, Heng; Liu, Xiaodong; Dong, Buwen

    2017-09-01

    Winter precipitation over Central Asia and the western Tibetan Plateau (CAWTP) is mainly a result of the interaction between the westerly circulation and the high mountains around the plateau. Empirical Orthogonal Functions (EOFs), Singular Value Decomposition (SVD), linear regression and composite analysis were used to analyze winter daily precipitation and other meteorological elements in this region from 1979 to 2013, in order to understand how interactions between the regional circulation and topography affect the intraseasonal variability in precipitation. The SVD analysis shows that the winter daily precipitation variability distribution is characterized by a dipole pattern with opposite signs over the northern Pamir Plateau and over the Karakoram Himalaya, similar to the second mode of EOF analysis. This dipole pattern of precipitation anomaly is associated with local anomalies in both the 700 hPa moisture transport and the 500 hPa geopotential height and is probably caused by oscillations in the regional and large-scale circulations, which can influence the westerly disturbance tracks and water vapor transport. The linear regression shows that the anomalous mid-tropospheric circulation over CAWTP corresponds to an anti-phase variation of the 500 hPa geopotential height anomalies over the southern and northern North Atlantic 10 days earlier (at 95% significance level), that bears a similarity to the North Atlantic Oscillation (NAO). The composite analysis reveals that the NAO impacts the downstream regions including CAWTP by controlling south-north two branches of the middle latitude westerly circulation around the Eurasian border. During the positive phases of the NAO, the northern branch of the westerly circulation goes around the northwest Tibetan Plateau, whereas the southern branch encounters the southwest Tibetan Plateau, which leads to reduced precipitation over the northern Pamir Plateau and increased precipitation over the Karakoram Himalaya, and

  2. Variability of the Antarctic Circumpolar Current transport through the Fawn Trough, Kerguelen Plateau

    Science.gov (United States)

    Vivier, Frédéric; Park, Young-Hyang; Sekma, Hela; Le Sommer, Julien

    2015-04-01

    The Kerguelen Plateau is a major topographic obstacle to the eastward flowing Antarctic Circumpolar Current (ACC). While approximately two-third of the ACC transport is diverted to the North, most of the remaining flow engulfs in the Fawn Trough, the only deep passage across the plateau. As part of the TRACK (TRansport ACross the Kerguelen plateau) project, three mooring lines of current meters were deployed in the Fawn Trough for one year in February 2009, underneath ground-track 94 of the Jason-2 satellite altimeter. Full depth CTD-LADCP casts carried out during the deployment cruise were previously analyzed to provide a comprehensive description of the regional circulation, featuring in particular a volume transport of ~43 Sv across the Fawn Trough (Park et al., 2009). Here we present a time series of the transport in the Fawn Trough estimated from current meter observations, featuring a mean eastward transport of 34 Sv (possibly biased low by at most 5 Sv) and a root mean squared variability of 6 Sv, consistent with LADCP estimates (43 Sv in February 2009 and 38 Sv in January 2010). In addition, we analyze to what extent the transport can be directly monitored from along-track satellite altimeter data, which would enable study of the variability of the Fawn Trough Current from a now 20-year long archive. The ability to reconstruct the flow from a limited set of moored instruments as well as from altimeter-derived surface geostrophic velocity is further assessed from synthetic data extracted from a high-resolution peri-Antarctic simulation. While a canonical method to derive transport from altimetry, previously applied to the Malvinas Current, gives here unsatisfactory comparisons with in situ estimates, an ad hoc approach using only the two northernmost mooring lines yields an estimate well correlated (~0.8) with in situ transport at subseasonal time scales during the one year period of observations. At interannual time scales, however, both methods provide

  3. A new phasmid gecko (Squamata: Diplodactylidae: Strophurus) from the Arnhem Plateau: more new diversity in rare vertebrates from northern Australia.

    Science.gov (United States)

    Oliver, Paul M; Parkin, Tom

    2014-10-22

    The Arnhem Plateau is a rugged expanse of sandstone escarpment in the Australian Monsoonal Tropics with a highly endemic biota. Here we describe a new species of small spinifex dwelling Strophurus (phasmid gecko) that also appears to be endemic to this region. Strophurus horneri sp. nov. can be diagnosed from all congeners by aspects of size, coloration and scalation. Even with the description of this new species, however, levels of morphological and genetic diversity within Strophurus from the stone country of the Northern Territory suggest additional divergent lineages are present. A number of recent studies have now provided preliminary evidence of evolutionary diversity within the Arnhem Plateau, but data remains scant and almost nothing is known about how topography and historical processes have shaped the endemic biota of this region

  4. Understanding of Grassland Ecosystems under Climate Change and Economic Development Pressures in the Mongolia Plateau

    Science.gov (United States)

    Qi, J.; Chen, J.; Shan, P.; Pan, X.; Wei, Y.; Wang, M.; Xin, X.

    2011-12-01

    The land use and land cover change, especially in the form of grassland degradation, in the Mongolian Plateau, exhibited a unique spatio-temporal pattern that is a characteristic of a mixed stress from economic development and climate change of the region. The social dimension of the region played a key role in shaping the landscape and land use change, including the cultural clashes with economic development, conflicts between indigenous people and business ventures, and exogenous international influences. Various research projects have been conducted in the region to focus on physical degradation of grasslands and/or on economic development but there is a lack of understanding how the social and economic dimensions interact with grassland ecosystems and changes. In this talk, a synthesis report was made based on the most recent workshop held in Hohhot, Inner Mongolia, of China, that specifically focused on climate change and grassland ecosystems. The report analyzed the degree of grassland degradation, its climate and social drivers, and coupling nature of economic development and conservation of traditional grassland values. The goal is to fully understand the socio-ecological-economic interactions that together shape the trajectory of the grassland ecosystems in the Mongolia Plateau.

  5. Heat flow in the Ozark Plateau, Arkansas and Missouri: relationship to groundwater flow

    Science.gov (United States)

    Meert, Joseph G.; Smith, Douglas L.; Fishkin, Len

    1991-09-01

    Heat flow values were calculated from direct measurements of temperature and thermal conductivity at thirteen sites in the Arkansas-Missouri Ozark Plateau region. These thirteen values are augmented by 101 estimates of heat flow, based on thermal conductivity measurements and temperature gradients extrapolated from bottom-hole temperatures. The regional heat flow profile ranges from 9 mW m -2 to over 80 mW m -2, but at least two distinct thermal regimes have been identified. Seven new heat flow determinations are combined with three previously published values for the St. Francois Mountains (SFM), a Precambrian exposure of granitic and rhyolitic basement rocks, average 47 mW m -2. Radioactive heat production of 76 samples of the exposed rocks in the SFM averages 2.4 μW m -2 and a typical continental basement contribution of 14 mW m -2 is implied. Conversely, the sedimentary rock sequence of the plateau is characterized by an anomalously low heat flow, averaging approximately 27 mW m -2. Groundwater transmissivity values that are based on data from 153 wells in deep regional aquifers demonstrate an inverse relationship to the observed heat flow patterns. The areas of high transmissivity that correspond to areas of low total heat flux suggest that the non-conservative vertical heat flow within the Ozark sedimentary sequence can be attributed to the effects of groundwater flow.

  6. Screening for contaminants of emerging concern in Northern Colorado Plateau Network waters: 2015 surface-water data

    Science.gov (United States)

    Weissinger, R; Battaglin, William A.; Bradley, Paul M.

    2016-01-01

    In 2015, as part of an on-going screening program for contaminants of emerging concern (CECs) in conjunction with the Environmental Protection Agency (EPA) Region 8, surface waters at 18 locations in or near seven national park units within the Northern Colorado Plateau Network (NCPN) were sampled for pesticides and pesticide degradation products, pharmaceuticals and personal care products, hormones, organic-wastewater-indictor chemicals, and nutrients. Most sites were sampled in spring (May or June) and fall (September).

  7. The effect of the Asian Monsoon to the atmospheric boundary layer over the Tibetan Plateau

    Science.gov (United States)

    Li, Maoshan; Su, Zhongbo; Chen, Xuelong; Zheng, Donghai; Sun, Fanglin; Ma, Yaoming; Hu, Zeyong

    2016-04-01

    needed temporal and spatial coupling and means for validation of mesoscale model simulations (Zhong et al., 2009, 2011). When these time series are integrated into energy balance analyses methods (Su, 2002, 2005) with reanalysis data, plateau scale diurnal radiative and turbulence fluxes can be generated (Oku et al., 2005; Su et al., 2010) for the study of the boundary layer atmospheric structures at plateau scale. As such regional land-atmosphere feedbacks and atmospheric boundary layer structures can be studied. The quantification of the multi-scale atmospheric boundary layer and land surface processes over the heterogeneous underlying surface of the Tibetan Plateau is a challenging problem that remains unsettled despite many years of efforts. Using field observation, truth investigation, land surface process parameterization and meso-scale simulation, the dynamical and thermal uniform function of the atmospheric boundary layer and its effect to the atmospheric boundary layer will be analyzed in this research. Results The different characteristics of the Boundary layer with Asia monsoon season exchange over TP The height of atmospheric boundary layer was higher before monsoon season than it in summer. It was around 3-4 km above the ground in spring, while it was 1-2 km during monsoon season. It due to sensible heat flux was stronger in spring than it in summer. Using wavelet analysis method, we decomposed the wind include horizontal and vertical velocity from radiosounding observational data. The reason of high boundary layer height was disclosed. Compared to the observation, the output of model was underestimation during spring, while it was reasonable in summer monsoon. The effect of the Asian Monsoon to the precipitation on the TP Numerical simulation of climate on the TP was implemented for the whole year of 2008 using WRF-Noah model. The output of the WRF model is compared to TRMM data set for precipitation and ERA-interim land product for soil moisture. Modeled

  8. Spontaneous collapse of the tibial plateau: radiological staging

    Energy Technology Data Exchange (ETDEWEB)

    Carpintero, P.; Leon, F.; Zafra, M. [University Hospital ' ' Reina Sofia' ' , Orthopaedic Department, Cordoba (Spain); Montero, R.; Carreto, A. [University Hospital ' ' Reina Sofia' ' , Radiology Department, Cordoba (Spain)

    2005-07-01

    This paper proposes a radiological staging system for necrosis of the tibial plateau, similar to those already developed for the hip and the medial femoral condyle. We retrospectively studied the clinical case histories and radiographic findings of 14 patients (15 affected knees) with histologically proven osteonecrosis of the tibial plateau. Stage I was marked by normal radiograph, but increased uptake in bone scan and subchondral areas of abnormal marrow signal intensity in magnetic resonance imaging (MRI), as reported in other osteonecrosis sites. Stage II was characterised by cystic and sclerotic changes, and stage III fracture of the medial rim of the medial tibial plateau and tibial plateau collapse were present. Stage IV was marked by joint narrowing. These changes appeared earlier and were more pronounced when there was genu varum/valgum or involvement of the lateral tibial plateau. The radiological evolution of the disease appears to follow a four-stage course over a period of roughly one year from the onset of symptoms. (orig.)

  9. Environmental control on the paleo- and environmental magnetic record on the Yermak Plateau, Arctic Ocean

    Science.gov (United States)

    Wiers, Steffen; Snowball, Ian; O'Regan, Matt; Almqvist, Bjarne

    2017-04-01

    The Yermak Plateau, situated north of Svalbard, has been recognized as one of several places in the Arctic Ocean where paleomagnetism yields controversial results. Despite low sedimentation rates, excursional paleomagnetic directions have been reconstructed from many cores in the region. Commonly reported geomagnetic excursions, i.e. Laschamp, Norwegian-Greenland-Sea and Blake, show considerably longer durations and younger ages compared to established short-lived geomagnetic polarity microchrons. An environmental control on the paleomagnetic record, connected to self-reversal during maghemitization of titanomagnetite has been proposed as one explanation for the wide occurrence of anomalous paleomagnetic data in the Arctic Ocean, but it remains unclear what mechanisms are responsible. Without independent stratigraphic control and independent dating it is difficult to distinguish between true and false records of the paleomagnetic field. Here we present a paleo- and environmental magnetic record from an 8.6 m long oriented Kasten core (PS92/39-02) collected at 1464 m water depth on the Yermak Plateau (81.94°N 13.82°E). The density and magnetic susceptibility fit well into the regional stratigraphy and allow for correlation of different parameters with independently dated records. During AF demagnetization zones with a weak-medium gyro-remanence and/or spurious ARM acquisition were observed at fields above 70 mT, but in some instances above 50 mT, coinciding with shallow to positive inclination zones. Based on a gyro-cleaned record the initial paleomagnetic age model fits well into the regional constraints. The top of the core was assigned to be recent, the first observed excursion was assigned to Laschamp (ca. 41ka), the second to Norwegian-Greenland Sea (ca. 70-80 ka) and the top of the third to Blake (ca. 110 ka). With no excursions observed below Blake, the bottom of the sediment sequence was assumed to be younger than 180 ka (the age of the Iceland Basin

  10. Oligocene Laccoliths on the Colorado Plateau: A Key to Understanding Cenozoic Rock Cooling and Exhumation

    Science.gov (United States)

    Murray, K. E.; Reiners, P. W.; Thomson, S. N.

    2014-12-01

    The Colorado Plateau is an exceptional region of high elevation, extensive canyonlands, and minor crustal deformation in the North American Cordillera. Numerous low-temperature thermochronology studies have attempted to constrain the timing and rate(s) at which this enigmatic Cenozoic landscape developed. However, such studies have struggled to robustly interpret the thermal histories of the Plateau's rocks because most contain detrital crystals with diverse time-temperature histories that are partially reset, which confounds efforts to see clear thermochronologic signals of Cenozoic erosion. To overcome this challenge, we targeted sample collection from places on the Plateau where rock thermal histories were reset by Oligocene magmatism: the thermal aureoles of laccolith-cored Henry, La Sal, and Abajo mountains. There, shallow plutons (i.e., laccoliths) heated the late Paleozoic and Mesozoic sedimentary rocks ca. 26 Ma, locally resetting apatite fission track and (U-Th)/He ages so they record subsequent Miocene-Quaternary cooling. Sandstone samples from each mountain range yield single-crystal apatite He ages that vary with effective U concentration (eU). In these key samples, minimum He ages are ~5 Ma with eU 60 ppm. We model and interpret these age-eU patterns together with (1) stratigraphic constraints, (2) the timing of magmatic heating constrained by zircon U/Pb laccolith geochronology, and (3) the extent of resetting temperatures >100 ˚C by apatite fission track analysis. Results require prolonged sample residence in the apatite He partial retention zone (40-60 ˚C) from 25 to 1 km/Myr in parts of the Henry and Abajo mountains. The Plio-Pleistocene was a time of change both regionally and globally, as Colorado River base level dropped with its final integration through the Grand Canyon ca. 5.3 Ma and global climate cooling possibly enhanced erosion rates on the Plateau's high-relief mountain ranges. Ongoing work evaluates the relationship between the

  11. Fraturas do planalto tibial Tibial plateau fractures

    Directory of Open Access Journals (Sweden)

    Maurício Kfuri Júnior

    2009-01-01

    Full Text Available As fraturas do planalto tibial são lesões articulares cujos princípios de tratamento envolvem a redução anatômica da superfície articular e a restauração funcional do eixo mecânico do membro inferior. Contribuem para a tomada de decisões no tratamento dessas fraturas o perfil do paciente, as condições do envelope de tecidos moles, a existência de outros traumatismos associados e a infraestrutura disponível para abordagens cirúrgicas. Para as fraturas de alta energia, o tratamento estagiado, seguindo o princípio do controle de danos, tem como prioridade a manutenção do alinhamento do membro enquanto se aguarda a resolução das más condições de tecidos moles. Já nos traumas de baixa energia, desde que os tecidos moles não sejam um fator adverso, o tratamento deve ser realizado em tempo único, com osteossíntese definitiva. Fixação estável e movimento precoce são variáveis diretamente relacionadas com os melhores prognósticos. Desenvolvimentos recentes, como os implantes com estabilidade angular, substitutos ósseos e imagens tridimensionais para controle intraoperatório, deverão contribuir para cirurgias menos invasivas e melhores resultados.Tibial plateau fractures are joint lesions that require anatomical reduction of joint surface and functional restoration of mechanical axis of a lower limb. Patient profile, soft tissue conditions, presence of associated injuries and the available infrastructure for the treatment all contribute to the decision making about the best treatment for these fractures. High-energy fractures are usually approached in a staged manner respecting the principle of damage control, and are primarily targeted to maintain limb alignment while the resolution unfavorable soft tissue conditions is pending. Low-energy trauma can be managed on a single-stage basis, provided soft tissues are not an adverse factor, with open reduction and internal f-ixation. Stable fixation and early painless joint

  12. Phylogeographic investigation and ecological niche modelling of the endemic frog species Nanorana pleskei revealed multiple refugia in the eastern Tibetan Plateau.

    Science.gov (United States)

    Wang, Bin; Xie, Feng; Li, Jiannan; Wang, Gang; Li, Cheng; Jiang, Jianping

    2017-01-01

    The largest plateau Tibetan Plateau supplied an excellent opportunity to investigate the influence of the Pleistocene events on the high-elevation species. To test for the alternative hypotheses of Pleistocene glacial refugia, we used partial sequences of two mitochondrial genes and one nuclear gene to examine the phylogeographic patterns of the endemic frog species Nanorana pleskei across its known range in the eastern Tibetan Plateau, and conducted species distribution modelling (SDM) to explore changes of its distribution range through current and paleo periods. In all data sets, the species was divided into lineage north occupying open plateau platform and lineage south colonizing the mountainous plateau. The divergence of two major clades was estimated at the early Pleistocene. In mtDNA, lineage north contained northeastern and northwestern sublineages, and lineage south had two overlapping-distributed sublineages. Different lineages possessed distinct demographic characteristics, i.e., subdivision in the northeastern sublineage, historical bottleneck effects and recent expansions in the northwestern sublineage and the southeastern sublineage. SDMs depicted that stable suitable habitats had existed in the upper-middle streams of the Yellow River, Dadu River, Jinsha River and Yalong River. These regions were also recognized as the ancestral areas of different lineages. In conclusion, Nanorana pleskei lineages have probably experienced long-term separations. Stable suitable habitats existing in upper-middle streams of major rivers on the eastern Tibetan Plateau and distinct demographic dynamics of different lineages indicated that the lineages possessed independent evolutionary processes in multiple glacial refugia. The findings verified the profound effects of Pleistocene climatic fluctuations on the plateau endemic species.

  13. Phylogeographic investigation and ecological niche modelling of the endemic frog species Nanorana pleskei revealed multiple refugia in the eastern Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Bin Wang

    2017-09-01

    Full Text Available The largest plateau Tibetan Plateau supplied an excellent opportunity to investigate the influence of the Pleistocene events on the high-elevation species. To test for the alternative hypotheses of Pleistocene glacial refugia, we used partial sequences of two mitochondrial genes and one nuclear gene to examine the phylogeographic patterns of the endemic frog species Nanorana pleskei across its known range in the eastern Tibetan Plateau, and conducted species distribution modelling (SDM to explore changes of its distribution range through current and paleo periods. In all data sets, the species was divided into lineage north occupying open plateau platform and lineage south colonizing the mountainous plateau. The divergence of two major clades was estimated at the early Pleistocene. In mtDNA, lineage north contained northeastern and northwestern sublineages, and lineage south had two overlapping-distributed sublineages. Different lineages possessed distinct demographic characteristics, i.e., subdivision in the northeastern sublineage, historical bottleneck effects and recent expansions in the northwestern sublineage and the southeastern sublineage. SDMs depicted that stable suitable habitats had existed in the upper-middle streams of the Yellow River, Dadu River, Jinsha River and Yalong River. These regions were also recognized as the ancestral areas of different lineages. In conclusion, Nanorana pleskei lineages have probably experienced long-term separations. Stable suitable habitats existing in upper-middle streams of major rivers on the eastern Tibetan Plateau and distinct demographic dynamics of different lineages indicated that the lineages possessed independent evolutionary processes in multiple glacial refugia. The findings verified the profound effects of Pleistocene climatic fluctuations on the plateau endemic species.

  14. Soil Moisture and Temperature Measuring Networks in the Tibetan Plateau and Their Hydrological Applications

    Science.gov (United States)

    Yang, Kun; Chen, Yingying; Qin, Jun; Lu, Hui

    2017-04-01

    Multi-sphere interactions over the Tibetan Plateau directly impact its surrounding climate and environment at a variety of spatiotemporal scales. Remote sensing and modeling are expected to provide hydro-meteorological data needed for these process studies, but in situ observations are required to support their calibration and validation. For this purpose, we have established two networks on the Tibetan Plateau to measure densely two state variables (soil moisture and temperature) and four soil depths (0 5, 10, 20, and 40 cm). The experimental area is characterized by low biomass, high soil moisture dynamic range, and typical freeze-thaw cycle. As auxiliary parameters of these networks, soil texture and soil organic carbon content are measured at each station to support further studies. In order to guarantee continuous and high-quality data, tremendous efforts have been made to protect the data logger from soil water intrusion, to calibrate soil moisture sensors, and to upscale the point measurements. One soil moisture network is located in a semi-humid area in central Tibetan Plateau (Naqu), which consists of 56 stations with their elevation varying over 4470 4950 m and covers three spatial scales (1.0, 0.3, 0.1 degree). The other is located in a semi-arid area in southern Tibetan Plateau (Pali), which consists of 25 stations and covers an area of 0.25 degree. The spatiotemporal characteristics of the former network were analyzed, and a new spatial upscaling method was developed to obtain the regional mean soil moisture truth from the point measurements. Our networks meet the requirement for evaluating a variety of soil moisture products, developing new algorithms, and analyzing soil moisture scaling. Three applications with the network data are presented in this paper. 1. Evaluation of Current remote sensing and LSM products. The in situ data have been used to evaluate AMSR-E, AMSR2, SMOS and SMAP products and four modeled outputs by the Global Land Data

  15. Fukushima nuclear accident recorded in Tibetan Plateau snow pits.

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    Ninglian Wang

    Full Text Available The β radioactivity of snow-pit samples collected in the spring of 2011 on four Tibetan Plateau glaciers demonstrate a remarkable peak in each snow pit profile, with peaks about ten to tens of times higher than background levels. The timing of these peaks suggests that the high radioactivity resulted from the Fukushima nuclear accident that occurred on March 11, 2011 in eastern Japan. Fallout monitoring studies demonstrate that this radioactive material was transported by the westerlies across the middle latitudes of the Northern Hemisphere. The depth of the peak β radioactivity in each snow pit compared with observational precipitation records, suggests that the radioactive fallout reached the Tibetan Plateau and was deposited on glacier surfaces in late March 2011, or approximately 20 days after the nuclear accident. The radioactive fallout existed in the atmosphere over the Tibetan Plateau for about one month.

  16. Moho offset across the northern margin of the tibetan plateau

    Science.gov (United States)

    Zhu; Helmberger

    1998-08-21

    Anomalous double-pulse teleseismic P-wave arrivals were observed at one station near the northern margin of the Tibetan Plateau. The azimuthal dependence of the waveform distortion and its absence at nearby stations indicated that the distortion was produced by receiver-side crustal heterogeneity. Modeling of the three-component data revealed a 15- to 20-kilometer Moho offset that occurs over a narrow lateral range of less than 5 kilometers. This east-west-striking offset separates the thick Tibetan Plateau crust from the Qaidam Basin crust. Such a sharp crustal thickness change implies a weak Tibetan Plateau crust that thickens vertically in response to penetration by India from the south and to blockage caused by a strong Qaidam Basin crust to the north.

  17. An avifaunal case study of a plateau from Goa, India: an eye opener for conservation of plateau ecosystems

    Directory of Open Access Journals (Sweden)

    Minal Desai

    2012-03-01

    Full Text Available The lateritic plateaux typical of the midlands between the Western Ghats and the coastal plains of the Arabian Sea are known to be a unique ecosystem with a sizeable endemic flora. However, there is a total lack of studies on the faunal diversity of these plateaux, which are currently experiencing enormous anthropogenic pressures. We conducted a year-long study on the avifauna of the Taleigao Plateau, Goa. The Taleigao Plateau harbours 114 species of birds, accounting for 37% of the avifaunal diversity of the state. The resident bird population did not vary significantly through the seasons. Among the migrant birds, Rosy Starling Sturnus roseus was particularly partial to the plateau. Besides, five species of larks, grassland specialists were also recorded on the plateau. However, the absence of forest birds like the Malabar Pied Hornbill and the Indian Grey Hornbill (recorded earlier and the predominance of habitat generalists like the House Crow and the Jungle Myna seemed to be the offshoot of heavy anthropogenic pressures on the plateau. It is recommended that at least some plateaux in the belt deserve to be protected from the impact of unsustainable developmental process

  18. Pollen and plant macrofossils at Lac de Fully (2135 m a.s.l.): Holocene forest dynamics on a highland plateau in the Valais, Switzerland

    NARCIS (Netherlands)

    Finsinger, W.; Tinner, W.

    2007-01-01

    We use pollen, stomata and plant-macrofossil records to infer Holocene timberline fluctuations and changes in forest composition at Lac Supérieur de Fully (2135 m a.s.l.), a small lake located near the modern regional timberline on a highland plateau in the Central Alps. Our records suggest that

  19. Transport in the plateau regime in a tokamak pedestal

    Science.gov (United States)

    Seol, J.; Shaing, K. C.

    2012-07-01

    In a tokamak H-mode, a strong E × B flow shear is generated during the L-H transition. Turbulence in a pedestal is suppressed significantly by this E × B flow shear. In this case, neoclassical transport may become important. The neoclassical fluxes are calculated in the plateau regime with the parallel plasma flow using their kinetic definitions. In an axisymmetric tokamak, the neoclassical particles fluxes can be decomposed into the banana-plateau flux and the Pfirsch-Schlüter flux. The banana-plateau particle flux is driven by the parallel viscous force and the Pfirsch-Schlüter flux by the poloidal variation of the friction force. The combined quantity of the radial electric field and the parallel flow is determined by the flux surface averaged parallel momentum balance equation rather than requiring the ambipolarity of the total particle fluxes. In this process, the Pfirsch-Schlüter flux does not appear in the flux surface averaged parallel momentum equation. Only the banana-plateau flux is used to determine the parallel flow in the form of the flux surface averaged parallel viscosity. The heat flux, obtained using the solution of the parallel momentum balance equation, decreases exponentially in the presence of sonic Mp without any enhancement over that in the standard neoclassical theory. Here, Mp is a combination of the poloidal E × B flow and the parallel mass flow. The neoclassical bootstrap current in the plateau regime is presented. It indicates that the neoclassical bootstrap current also is related only to the banana-plateau fluxes. Finally, transport fluxes are calculated when Mp is large enough to make the parallel electron viscosity comparable with the parallel ion viscosity. It is found that the bootstrap current has a finite value regardless of the magnitude of Mp.

  20. Active shortening and intermontane basin formation in the central Puna Plateau: Salar de Pocitos, NW Argentina (24°37'S, 67°03'W)

    Science.gov (United States)

    Strecker, Manfred; Bookhagen, Bodo; Freymark, Jessica; Pingel, Heiko; Alonso, Ricardo N.

    2015-04-01

    Similar to other Cenozoic orogenic plateaus, extensional tectonics associated with mafic volcanism typifies the Altiplano-Puna of the southern Central Andes, while the flanks of the plateau and adjacent foreland areas experience shortening. Extensional tectonism in the plateau region since the late Miocene has been explained with delamination of lithospheric mantle. However, new evidence for protracted basin-wide shortening in the Salar de Pocitos region in the south-central Puna documents that the kinematic changeover from shortening to extension is highly diachronous. In this study we assess the deformation and geomorphic history of the Salar de Pocitos region using DGPS surveys, CRN dating of deformed pediment surfaces, and U/Pb dating of volcanic ash horizons in deformed strata. With average elevations of about 3.7 km the Altiplano-Puna is a first-order morphotectonic province of the southern central Andes and constitutes the world's second largest orogenic plateau. With few exceptions the Andean plateau consists of internally drained, partly coalesced sedimentary basins that are mainly bordered by reverse-fault bounded ranges, 5 to 6 km high. While there are many unifying plateau characteristics in the Altiplano (north) and Puna (south), including internal drainage, semi-arid to arid climate and associated deposition of evaporites, there are notable differences between both plateau sectors. In contrast to the vast Altiplano basin of Bolivia, the Argentine Puna comprises numerous, smaller and partly coalesced basins that reflect continued comparmentalization by the combined effects of tectonism and volcanic activity. The N-S oriented Salar de Pocitos basin is the vestige of a formerly contiguous sedimentary basin within the Puna interior. Unlike many other basins in this region it is bordered by the limb of an anticline developed in Tertiary sedimentary rocks on the west, while the eastern border is a reverse-faulted range front. To the north and south the

  1. Geodetic Constraints on the Qinghai-Tibetan Plateau Present-Day Geophysical Processes

    Directory of Open Access Journals (Sweden)

    Kamil Erkan

    2011-01-01

    Full Text Available The Qinghai-Tibetan Plateau is the largest and the highest area in the world with distinct and competing surface and subsurface processes. The entire Plateau has been undergoing crustal deformation and accompanying isostatic uplift as a result of the Cenozoic collision of the Indian and Eurasian continents. Regional secular surface mass changes include the melting of mountain glaciers and ice caps, and permafrost layer degradation due to global warming. There is also a plausible effect of glacial isostatic adjustment due to the removal of a possible Pleistocene ice-sheet. In this article, we present an assessment of the sizes and extents of these competing interior and exterior dynamical processes, and their possible detections using contemporary space geodetic techniques. These techniques include, in addition to GPS, satellite radar altimetry over land, and temporal gravity field measurements from the Gravity Recovery and Climate Experiment (GRACE satellite mission. These techniques are complementary: land satellite altimetry, similar to GPS, is sensitive only to surface uplift, whereas GRACE is sensitive to both surface uplift and mass changes inside the Earth. Each process may dominate the others in a particular region. Our analysis shows that GRACE data are more sensitive (than GPS or land altimetry to hydrologic and meteorology signals, some of which are larger than the combined effect of geodynamic processes and permafrost degradation.

  2. Comparative study on PCDD/F pollution in soil from the Antarctic, Arctic and Tibetan Plateau.

    Science.gov (United States)

    Jia, Shenglan; Wang, Qiang; Li, Li; Fang, Xuekun; Shi, Yehong; Xu, Weiguang; Hu, Jianxin

    2014-11-01

    The concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) in 35 soil samples collected from Fildes Peninsula in the Antarctic, Ny-Ålesund in the Arctic, and Zhangmu-Nyalam in the Tibetan Plateau were reported in this study. A comparison of the total concentration and TEQ of PCDD/Fs at the Three Poles was conducted. Both the total concentration and TEQ of PCDD/Fs demonstrates a decreasing trend in the order of Zhangmu-Nyalam (mean: 26.22 pg/g, 0.37 pg I-TEQ/g)>Ny-Ålesund (mean: 9.97 pg/g, 0.33 pg I-TEQ/g)>Fildes Peninsula (mean: 2.18 pg/g, 0.015 pg I-TEQ/g) (p<0.05). In all samples, the congener and homologue profiles dominated with higher (seven and eight) chlorinated PCDD/Fs (more than 85% of the total mass percentage of PCDD/Fs) at the Three Poles. Finally, a FLEXPART backward simulation was used to preliminarily identify the potential local and regional anthropogenic sources of PCDD/Fs. The results imply that the air masses passing over surrounding regions with significant PCDD/F emissions might contribute to the occurrence of PCDD/Fs in both the Arctic and Tibetan Plateau. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. A Field Trip Guide to the Petrology of Quaternary Volcanism on the Yellowstone Plateau

    Science.gov (United States)

    Vazquez, Jorge A.; Stelten, Mark; Bindeman, Ilya N.; Cooper, Kari M

    2017-12-19

    The Yellowstone Plateau is one of the largest manifestations of silicic volcanism on Earth, and marks the youngest focus of magmatism associated with the Yellowstone Hot Spot. The earliest products of Yellowstone Hot Spot volcanism are from ~17 million years ago, but may be as old as ~32 Ma, and include contemporaneous eruption of voluminous mafic and silicic magmas, which are mostly located in the region of northwestern Nevada and southeastern Oregon. Since 17 Ma, the main locus of Yellowstone Hot Spot volcanism has migrated northeastward producing numerous silicic caldera complexes that generally remain active for ~2–4 million years, with the present-day focus being the Yellowstone Plateau. Northeastward migration of volcanism associated with the Yellowstone Hot Spot resulted in the formation of the Snake River Plain, a low relief physiographic feature extending ~750 kilometers from northern Nevada to eastern Idaho. Most of the silicic volcanic centers along the Snake River Plain have been inundated by younger basalt volcanism, but many of their ignimbrites and lava flows are exposed in the extended regions at the margins of the Snake River Plain. 

  4. Impacts of Tibetan Plateau uplift on atmospheric dynamics and associated precipitation δ18O

    Science.gov (United States)

    Botsyun, Svetlana; Sepulchre, Pierre; Risi, Camille; Donnadieu, Yannick

    2016-06-01

    Palaeoelevation reconstructions of mountain belts have become a focus of modern science since surface elevation provides crucial information for understanding both geodynamic mechanisms of Earth's interior and the influence of mountain growth on climate. Stable oxygen isotopes palaeoaltimetry is one of the most popular techniques nowadays, and relies on the difference between δ18O of palaeo-precipitation reconstructed using the natural archives, and modern measured values for the point of interest. Our goal is to understand where and how complex climatic changes linked with the growth of mountains affect δ18O in precipitation. For this purpose, we develop a theoretical expression for the precipitation composition based on the Rayleigh distillation and the isotope-equipped atmospheric general circulation model LMDZ-iso outputs. Experiments with reduced height over the Tibetan Plateau and the Himalayas have been designed. Our results show that the isotopic composition of precipitation is very sensitive to climate changes related to the growth of the Himalayas and Tibetan Plateau. Specifically our simulations suggest that only 40 % of sampled sites for palaeoaltimetry depict a full topographic signal, and that uplift-related changes in relative humidity (northern region) and precipitation amount (southern region) could explain absolute deviations of up to 2.5 ‰ of the isotopic signal, thereby creating biases in palaeoelevation reconstructions.

  5. Two Prehistoric Silver Votive Plaques from the Šentviška Planota Plateau

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    Boštjan Laharnar

    2014-07-01

    Full Text Available The paper presents two silver votive plaques found on the sites Vrh Gradu and Berlotov Rob on the Šentviška Planota plateau in the Tolmin region, Slovenia. Vrh Gradu is a narrow ridge situated on the edge of the plateau, high above the gorge of the Idrijca River. The site has yielded a considerable quantity of archaeological finds, dating from Late Bronze Age to the Late Roman period. Among the prehistoric and Roman items there stands out a silver plaque bearing a Venetic inscription. A few kilometres to the east lies the Berlotov Rob site. This rocky, dome-like hill, furrowed by karstic phenomena, already seems to have impressed prehistoric inhabitants as it has yielded numerous archaeological items dating between the 5th  century BC and the beginning of the Roman period. An exceptional find is a silver circular plaque bearing astral symbols. The two items under discussion importantly further our understan- ding of the pre-Roman community in the Soča region. They strongly argue for the use of writing and of time measurement, and possibly for lunar standstill orientations of the sites.

  6. Integrated risk governance in the Yungui Plateau, China: The 2008 ice-snow storm disaster

    Directory of Open Access Journals (Sweden)

    Qian Ye

    2012-05-01

    Full Text Available Yungui Plateau in Southwestern China is regarded as one of the major bio- and cultural diversity centers in the world because it contains a remarkable variety of ecological niches and ethnic groups. Due to its unique mountain geographic landscape and domination by a monsoon climate, it has high vulnerabilities and is frequently hit by various climatic and geological hazards such as droughts, floods, earthquakes, and landslides. In the past two decades, while the region has enjoyed rapid social and economic development, vegetation degradation, water pollution and soil loss, as well as other environmental problems, have become major concerns in the region. In January 2008, nearly half of China was hit by an unprecedented series of hazards of low temperature, persistent rain, snow, and a series of ice storms with South China suffering the most. In this paper, with a comprehensive overview of the causes and consequences of the disaster, a disaster chain in Yungui Plateau is identified and environmental, social, economic and political factors are analyzed under a framework of integrated risk governance.

  7. A field trip guide to the petrology of Quaternary volcanism on the Yellowstone Plateau

    Science.gov (United States)

    Vazquez, Jorge A.; Stelten, Mark; Bindeman, Ilya N.; Cooper, Kari

    2017-12-19

    The Yellowstone Plateau is one of the largest manifestations of silicic volcanism on Earth, and marks the youngest focus of magmatism associated with the Yellowstone Hot Spot. The earliest products of Yellowstone Hot Spot volcanism are from ~17 million years ago, but may be as old as ~32 Ma, and include contemporaneous eruption of voluminous mafic and silicic magmas, which are mostly located in the region of northwestern Nevada and southeastern Oregon. Since 17 Ma, the main locus of Yellowstone Hot Spot volcanism has migrated northeastward producing numerous silicic caldera complexes that generally remain active for ~2–4 million years, with the present-day focus being the Yellowstone Plateau. Northeastward migration of volcanism associated with the Yellowstone Hot Spot resulted in the formation of the Snake River Plain, a low relief physiographic feature extending ~750 kilometers from northern Nevada to eastern Idaho. Most of the silicic volcanic centers along the Snake River Plain have been inundated by younger basalt volcanism, but many of their ignimbrites and lava flows are exposed in the extended regions at the margins of the Snake River Plain. 

  8. Internal Plateau in Short GRBs and Quark Stars

    Science.gov (United States)

    Li, Ang

    I summarize our recent calculations on quark stars (QSs), for the purpose of explaining some short gamma-ray bursts characterized by internal plateau in their early X-ray afterglow. According to the present plateau sample, the QS central engine model is demonstrated to more preferred than the original neutron star (NS) one. New QS equation of states (PMQS1, PMQS2, PMQS3) are then proposed, respecting fully the observed burst data and the mass distribution of the Galactic NS-NS systems.

  9. Seismology Across the Northeastern Edge of the Tibetan Plateau

    Science.gov (United States)

    Zhao, W.; Brown, L.; Wu, Z.; Klemperer, S. L.; Shi, D.; Mechie, J.; Su, H.; Tilmann, F.; Karplus, M. S.; Makovsky, Y.

    2008-11-01

    On 12 May, a great earthquake (Ms = 8.0) on the Longmenshan thrust fault rumbled through China's Sichuan province, killing more than 69,000 people and injuring 374,000. The Longmenshan thrust is part of the eastern border of the Tibetan Plateau, but it is not the plateau's only restless margin. An even larger earthquake (Ms = 8.1) on the Kunlun fault shook northeastern Tibet in 2001, fortunately in a sparsely populated area. These massive quakes underscore the importance of understanding the tectonic response of Asia to collision by India.

  10. Fractional Quantum Hall Plateau Transitions and Composite Fermi Liquids

    Science.gov (United States)

    Cho, Gil Young; Moon, Eun-Gook; Fradkin, Eduardo

    We will investigate relationship between the fractional quantum Hall plateau transition from Laughlin state at ν =1/2 n + 1 to a trivial insulator, and composite Fermi liquid at ν =1/2 (2 n + 1) . We use the recently-developed quantum field theoretic technique, 3d dualities, in combinations with the coupled-wire descriptions for quantum Hall states. We will show that we can also access various other phases, including non-abelian paired states at ν =1/2 (2 n + 1) , from the plateau transition. This work is supported by the Brain Korea 21 PLUS Project of Korea Government and KAIST start-up funding (GYC & EGM).

  11. Radiogenic and Stable Isotope and Hydrogeochemical Investigation of Groundwater, Pajarito Plateau and Surrounding Areas, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Patrick Longmire, Michael Dale, Dale Counce, Andrew Manning, Toti Larson, Kim Granzow, Robert Gray, and Brent Newman

    2007-07-15

    From October 2004 through February 2006, Los Alamos National Laboratory, the New Mexico Environment Department-Department of Energy Oversight Bureau, and the United States Geological Survey conducted a hydrochemical investigation. The purpose of the investigation was to evaluate groundwater flow paths and determine groundwater ages using tritium/helium-3 and carbon-14 along with aqueous inorganic chemistry. Knowledge of groundwater age and flow paths provides a technical basis for selecting wells and springs for monitoring. Groundwater dating is also relevant to groundwater resource management, including aquifer sustainability, especially during periods of long-term drought. At Los Alamos, New Mexico, groundwater is either modern (post-1943), submodern (pre-1943), or mixed (containing both pre- and post-1943 components). The regional aquifer primarily consists of submodern groundwater. Mixed-age groundwater results from initial infiltration of surface water, followed by mixing with perched alluvial and intermediate-depth groundwater and the regional aquifer. No groundwater investigation is complete without using tritium/helium-3 and carbon-14 dating methods to quantify amounts of modern, mixed, and/or submodern components present in samples. Computer models of groundwater flow and transport at Los Alamos should be calibrated to groundwater ages for perched intermediate zones and the regional aquifer determined from this investigation. Results of this study clearly demonstrate the occurrence of multiple flow paths and groundwater ages occurring within the Sierra de los Valles, beneath the Pajarito Plateau, and at the White Rock Canyon springs. Localized groundwater recharge occurs within several canyons dissecting the Pajarito Plateau. Perched intermediate-depth groundwater and the regional aquifer beneath Pueblo Canyon, Los Alamos Canyon, Sandia Canyon, Mortandad Canyon, Pajarito Canyon, and Canon de Valle contain a modern component. This modern component consists

  12. Deformation Mechanism of the Northern Tibetan Plateau as Revealed by Magnetotelluric Data

    Science.gov (United States)

    Zhang, Letian; Wei, Wenbo; Jin, Sheng; Ye, Gaofeng; Xie, Chengliang

    2017-04-01

    As a unique geologic unit on the northern margin of the Tibetan Plateau, the Qaidam Basin plays a significant role in constraining the vertical uplift and horizontal expansion of the northern and northeastern Tibetan Plateau. However, due to its complex evolution history and difficult logistic condition, deformation mechanism of the lithosphere beneath the Qaidam Basin is still highly debated. To better understand the lithospheric electrical structure and deformation mechanism of the Qaidam Basin, A 250 km long, NE-SW directed Magnetotelluric (MT) profile was finished in the northern portion of the Basin, which is roughly perpendicular to the thrust fault systems on the western and eastern margins of the Basin, as well as anticlinorium systems within the Basin. The profile consists of 20 broad-band MT stations and 5 long-period MT stations. Original time series data is processed with regular robust routines. Dimensionality and regional strike direction are determined for the dataset through data analysis. Based on the analysis results, 2D inversions were performed to produce a preferred model of the lithospheric electrical structure beneath the northern Qaidam Basin. Uncertainty analysis of the 2D inversion model was also conducted based on a data resampling approach. The outcome 2D electrical model was further used to estimate the distribution of temperature and melt fraction in the upper mantle based on laboratory-determined relationships between the electrical conductivity and temperature of nominally anhydrous minerals and basaltic melt by using the mixing law of Hashin-Shtrikman's bounds. All these results suggest that: (1) the crust-mantle boundary is imaged as a conductive layer beneath the western Qaidam Basin, with its temperature estimated to be 1200-1300 °C and melt fraction 5-8%, indicating decoupling deformation of the crust and upper mantle. (2) A large-scale east-dipping conductor is imaged beneath the eastern Qaidam Basin. This conductor extends

  13. The long-term trends (1982-2006) in vegetation greenness of the alpine ecosystem in the Qinghai-Tibetan Plateau

    Science.gov (United States)

    Zhang, Li; Guo, Huadong; Wang, Cuizhen; Ji, Lei; Li, Jing; Wang, Kun; Dai, Lin

    2014-01-01

    The increased rate of annual temperature in the Qinghai-Tibetan Plateau exceeded all other areas of the same latitude in recent decades. The influence of the warming climate on the alpine ecosystem of the plateau was distinct. An analysis of alpine vegetation under changes in climatic conditions was conducted in this study. This was done through an examination of vegetation greenness and its relationship with climate variability using the Advanced Very High Resolution Radiometer satellite imagery and climate datasets. Vegetation in the plateau experienced a positive trend in greenness, with 18.0 % of the vegetated areas exhibiting significantly positive trends, which were primarily located in the eastern and southwestern parts of the plateau. In grasslands, 25.8 % of meadows and 14.1 % of steppes exhibited significant upward trends. In contrast, the broadleaf forests experienced a trend of degradation. Temperature, particularly summer temperature, was the primary factor promoting the vegetation growth in the plateau. The wetter and warmer climate in the east contributed to the favorable conditions for vegetation. The alpine meadow was mostly sensitive to temperature, while the steppes were sensitive to both temperature and precipitation. Although a warming climate was expected to be beneficial to vegetation growth in the alpine region, the rising temperature coupled with reduced precipitation in the south did not favor vegetation growth due to low humidity and poor soil moisture conditions.

  14. 40Ar/39Ar dating of Quaternary lavas in northwest Iran: constraints on the landscape evolution and incision rates of the Turkish-Iranian plateau

    Science.gov (United States)

    Allen, Mark B.; Mark, Darren F.; Kheirkhah, Monireh; Barfod, Dan; Emami, Mohammad H.; Saville, Christopher

    2011-06-01

    We report five new 40Ar/39Ar ages for basaltic lavas in the Maku region of northwest Iran, between ca. 1.87 and 0.40 Ma, which help constrain the tectonic and landscape evolution of this part of the Turkish-Iranian plateau. Flows originated from the composite volcanoes Ararat (Agri Dagi), Tendürek and Yigit Dagi, in eastern Turkey (Anatolia). These volcanoes are within the Turkish-Iranian plateau, which is a consequence of the Arabia-Eurasia collision, but has a poorly constrained evolution and surface uplift history. Current plateau elevations are typically 1.5-2 km, and relief between non-volcanic summits and basins is typically on the scale of ˜1 km. Samples are from flows that passed along pre-existing river valleys. Gorges were cut by re-established rivers after the eruptions, but the great majority of the local relief (˜95 per cent) lies above the sampled flows and so most likely pre-dates the volcanism. Gorge depths and lava ages allow local Quaternary fluvial incision rates to be calculated, which are ˜0.01 to 0.05 mm yr-1. These rates imply slow surface uplift of this part of the Turkish-Iranian plateau during the Quaternary. We therefore constrain the generation of the great majority of relief in the study area to be pre-Quaternary, and caused by the tectonic construction of the plateau, rather than a subcrustal origin related to the Quaternary magmatism.

  15. The response of Asian summer monsoon to the Tibetan plateau heating simulated by ECHAM5/MPIOM and COSMOS-CLM

    Science.gov (United States)

    Fallah, Bijan; Sodoudi, Sahar; Cubasch, Ulrich

    2014-05-01

    The role of Tibetan plateau in driving the Asian summer monsoon system is still debating. In this study the physical climate model ECHAM5 (European Center, HAMburg) version 5.4.01 /MPIOM (Max Planck Institute Ocean Model) version 1.3.1 is used to study the potential role of Tibetan Plateau on Asian summer monsoon. The ECHAM5 model was integrated at T31 resolution with 19 levels and the MPI-OM ocean model at GR30 resolution with 40 levels for a period of 500 years (1500-2000 AD) for two experiments: a) with recent standard orography and b) with no Tibetan plateau. In the sensitivity simulation, we flattened the Tibetan plateau in 10-year time-steps to the final threshold of 500 meters. The subgrid-scale orographic drag was also considered by applying the parameterization scheme from Lott and Miller, 1996. Shallow ocean in the sensitivity simulation reached the equilibrium state after 300 years of integration. Deep ocean did not show an equilibrium state in the simulation with flattened Tibet. The large scale patterns of Asian summer monsoon are mostly unaffected by removing the Tibetan plateau, except a decrease of precipitation for the East China. Spatial pattern of summer surface temperature shows a decrease (up to -10 °C) over North Atlantic Ocean and a remarkable increase (up to 15 °C) over Tibetan plateau. Therefore, Tibet affects the atmospheric teleconnetion between the North Atlantic and the Asian monsoon system. In order to study the local orographically-induced effects on monsoon system, we have further applied the high resolution (horizontal grid spacing of 0.5 ) non-hydrostatic regional COSMO model in CLimate Mode (COSMO-CLM or CCLM) version 4.8_clm17 developed by the German Weather Service. The lateral boundary conditions were derived from the previous Atmosphere-Ocean General Circulation Model (AOGCM) simulations. Regional climate model simulations were started from initial conditions on 1 January 1979 for a period of 20 years. In the next step

  16. Tracing Altiplano-Puna plateau surface uplift via radiogenic isotope composition of Andean arc lavas

    Science.gov (United States)

    Scott, E. M.; Allen, M. B.; Macpherson, C.; McCaffrey, K. J. W.; Davidson, J.; Saville, C.

    2016-12-01

    We have compiled published geochemical data for Jurassic to Holocene Andean arc lavas from 5oN to 47oS, covering the current extent of the northern, central and southern volcanic zones. Using this dataset we evaluate the spatial and temporal evolution of age corrected Sr- and Nd-radiogenic isotopes in arc lavas at a continental-scale, in order to understand the tectonic and surface uplift histories of the Andean margin. It has long been noted that baseline 87Sr/86Sr and 143Nd/144Nd ratios of Quaternary lavas from the central volcanic zone, located within the Altiplano-Puna plateau, are distinct from volcanic rocks to the north and south. This is commonly attributed to greater crustal thickness, which increases to roughly twice that of the average continental crust within the Altiplano-Puna plateau. By comparing 87Sr/86Sr and 143Nd/144Nd ratios in Quaternary lavas to published crustal thickness models, present day topography and the compositions of basement terranes, we note that Sr- and Nd-isotope values of Quaternary lavas are an effective proxy for present day regional elevation. In contrast, variation in basement terranes has only a small, second order effect on isotopic composition at the scale of our study. Using this isotopic proxy, we infer the spatial extent of the plateau and its surface uplift history from the Jurassic to the present. Our results concur with a crustal thickening model of continued surface uplift, which initiated in the Altiplano, with deformation propagating southwards into the Puna throughout the Neogene and then continuing in central Chile and Argentina up to the present day.

  17. Loess and Loess-like Sediments on the Tibetan Plateau: New Results and Findings

    Science.gov (United States)

    Lehmkuhl, F.

    2014-12-01

    Aeolian, loess-like sediments distributed as mantles of silt covering the bedrock and debris are widespread depositions in the Qilain Shan and on the Tibetan Plateau (Lehmkuhl 1997). Up to now little is known about the timing and distribution of these late Quaternary sediments originated from far and local transported aeolian dust and sand. They represent valuable archives about environmental change during the late Quaternary. In addition, this fine material is important for growth of the vegetation cover and for water storage and nomadic life. Radiocarbon and luminescence dating provide information concerning their timing to the end of the last glacial cycle and especially to the Holocene, as some of them include loess-paleosol sequences. In addition, valuable information on paleoenvironmental conditions was acquired by grain-size distribution and geochemical analyses (e.g. Nottebaum et al. 2014, Lehmkuhl et. al. 2014). This contribution mainly focuses on the Qilian Shan, the northeastern and southern Tibetan Plateau. Lehmkuhl F. (1997). The spatial distribution of loess and loess-like sediments in the mountain areas of Central and High Asia, Zeitschrift für Geomorphologie, N.F., Suppl.-Bd. 111, 97-116. Lehmkuhl F., Schulte P., Zhao H., Hülle D., Protze J., Stauch G. (2014). Timing and spatial distribution of loess and loess-like sediments in the mountain areas of the northeastern Tibetan Plateau, Catena 117, 22-33. Nottebaum V., Lehmkuhl F., Stauch G., Hartmann K., Wünnemann B, Schimpf S, Lu H. (2014): Regional grain size variations in aeolian sediments along the transition between Tibetan highlands and northwestern Chinese deserts: The influence of geomorphological settings on aeolian transport pathways, Earth Surface Processes and Landforms, in press. DOI: 10.1002/esp.3590

  18. Monotony, Isolation and Backward Agriculture. Travel Accounts of 19th Century and Agrarian History of Bogota Plateau (Colombia

    Directory of Open Access Journals (Sweden)

    Katherinne Giselle Mora Pacheco

    2015-07-01

    Full Text Available Different works of Agrarian History reproduce a similar description of Bogota Plateau (Colombia throughout the nineteenth century: agricultural use since colonial times; vast fields of wheat and barley; abrupt replacement of crops by cattle; agricultural crisis linked to the agro-export booms and the demand for tropical products that could not be obtained above 2000 meters. This paper discusses how this approach has perpetuated descriptions of travelers who visited the region during the nineteenth century and wrote up their notebooks based on their origins, objectives, political and economic interests, or from affirmations of their guides and informants. This article rebuilds a profile of travelers that are most often quoted by historians, their views about the Plateau landscape and its farming and ranching, and their influence on today reconstructions of the agrarian history of Bogota Plateau along nineteenth century. This text invites to contrast the travel accounts among themselves and with another sources, and also to incorporate the results of the research about the Colonial period and the biophysical conditions of the regions under study in the analysis.

  19. Retrogressive thaw slumps temper dissolved organic carbon delivery to streams of the Peel Plateau, NWT, Canada

    Directory of Open Access Journals (Sweden)

    C. A. Littlefair

    2017-12-01

    Full Text Available In Siberia and Alaska, permafrost thaw has been associated with significant increases in the delivery of dissolved organic carbon (DOC to recipient stream ecosystems. Here, we examine the effect of retrogressive thaw slumps (RTSs on DOC concentration and transport, using data from eight RTS features on the Peel Plateau, NWT, Canada. Like extensive regions of northwestern Canada, the Peel Plateau is comprised of thick, ice-rich tills that were deposited at the margins of the Laurentide Ice Sheet. RTS features are now widespread in this region, with headwall exposures up to 30 m high and total disturbed areas often exceeding 20 ha. We find that intensive slumping on the Peel Plateau is universally associated with decreasing DOC concentrations downstream of slumps, even though the composition of slump-derived dissolved organic matter (DOM; assessed using specific UV absorbance and slope ratios is similar to permafrost-derived DOM from other regions. Comparisons of upstream and downstream DOC flux relative to fluxes of total suspended solids suggest that the substantial fine-grained sediments released by RTS features may sequester DOC. Runoff obtained directly from slump rill water, above entry into recipient streams, indicates that the deepest RTS features, which thaw the greatest extent of buried, Pleistocene-aged glacial tills, release low-concentration DOC when compared to paired upstream, undisturbed locations, while shallower features, with exposures that are more limited to a relict Holocene active layer, have within-slump DOC concentrations more similar to upstream sites. Finally, fine-scale work at a single RTS site indicates that temperature and precipitation serve as primary environmental controls on above-slump and below-slump DOC flux, but it also shows that the relationship between climatic parameters and DOC flux is complex for these dynamic thermokarst features. These results demonstrate that we should expect clear variation in

  20. Retrogressive thaw slumps temper dissolved organic carbon delivery to streams of the Peel Plateau, NWT, Canada

    Science.gov (United States)

    Littlefair, Cara A.; Tank, Suzanne E.; Kokelj, Steven V.

    2017-12-01

    In Siberia and Alaska, permafrost thaw has been associated with significant increases in the delivery of dissolved organic carbon (DOC) to recipient stream ecosystems. Here, we examine the effect of retrogressive thaw slumps (RTSs) on DOC concentration and transport, using data from eight RTS features on the Peel Plateau, NWT, Canada. Like extensive regions of northwestern Canada, the Peel Plateau is comprised of thick, ice-rich tills that were deposited at the margins of the Laurentide Ice Sheet. RTS features are now widespread in this region, with headwall exposures up to 30 m high and total disturbed areas often exceeding 20 ha. We find that intensive slumping on the Peel Plateau is universally associated with decreasing DOC concentrations downstream of slumps, even though the composition of slump-derived dissolved organic matter (DOM; assessed using specific UV absorbance and slope ratios) is similar to permafrost-derived DOM from other regions. Comparisons of upstream and downstream DOC flux relative to fluxes of total suspended solids suggest that the substantial fine-grained sediments released by RTS features may sequester DOC. Runoff obtained directly from slump rill water, above entry into recipient streams, indicates that the deepest RTS features, which thaw the greatest extent of buried, Pleistocene-aged glacial tills, release low-concentration DOC when compared to paired upstream, undisturbed locations, while shallower features, with exposures that are more limited to a relict Holocene active layer, have within-slump DOC concentrations more similar to upstream sites. Finally, fine-scale work at a single RTS site indicates that temperature and precipitation serve as primary environmental controls on above-slump and below-slump DOC flux, but it also shows that the relationship between climatic parameters and DOC flux is complex for these dynamic thermokarst features. These results demonstrate that we should expect clear variation in thermokarst

  1. The Deep Atmospheric Boundary Layer and Its Significance to the Stratosphere and Troposphere Exchange over the Tibetan Plateau

    Science.gov (United States)

    Chen, Xuelong; Añel, Juan A.; Su, Zhongbo; de la Torre, Laura; Kelder, Hennie; van Peet, Jacob; Ma, Yaoming

    2013-01-01

    In this study the depth of the atmospheric boundary layer (ABL) over the Tibetan Plateau was measured during a regional radiosonde observation campaign in 2008 and found to be deeper than indicated by previously measurements. Results indicate that during fair weather conditions on winter days, the top of the mixed layers can be up to 5 km above the ground (9.4 km above sea level). Measurements also show that the depth of the ABL is quite distinct for three different periods (winter, monsoon-onset, and monsoon seasons). Turbulence at the top of a deep mixing layer can rise up to the upper troposphere. As a consequence, as confirmed by trajectory analysis, interaction occurs between deep ABLs and the low tropopause during winter over the Tibetan Plateau. PMID:23451108

  2. Foam drainage on the microscale - II. Imaging flow through single Plateau borders

    NARCIS (Netherlands)

    Koehler, S.A.; Hilgenfeldt, Sascha; Weeks, E.R.; Stone, H.A.

    2004-01-01

    The liquid in foam forms an interconnected network, which is composed of Plateau borders, nodes, and films. One of the dominant pathways for foam drainage is flow through Plateau borders, and we use confocal microscopy to obtain experimental results for the flow fields inside individual Plateau

  3. lateritic weathering of granite-gneiss in obudu plateau, south ...

    African Journals Online (AJOL)

    DJFLEX

    This paper reports the chemical, mineralogical and textural changes involved in the lateritization of granite-gneiss in. Obudu plateau and establishes that the susceptibility of constituent minerals to lateritic weathering is in the sequence; feldspar, Hornblende, Biotite, Quartz. Most of the chemical constituents of the basement ...

  4. Predictors of Male Condom Utilization in Plateau State, Nigeria ...

    African Journals Online (AJOL)

    This study aimed to assess the condom utilization and predictors of condom use among male respondents in Plateau State. Methodology: An analysis of secondary data of the 2013 Nigeria Demographic Health Survey dataset was done. Data were collected through a cross‑sectional study using multistage cluster sampling ...

  5. Protozoan Diversity in a productive fishpond of a tropical plateau ...

    African Journals Online (AJOL)

    A survey of the Protozoan species diversity in a productive fishpond of the Jos Plateau, Nigeria was investigated at 7 day interval over a period of 11 months. Samples were collected from water column and sediment. Protozoans were found to compose of the flagellates sarcodines and cilliates. There was a significant ...

  6. Outcome of cataract surgeries in Plateau State, Nigeria | Odugbo ...

    African Journals Online (AJOL)

    Aim: To evaluate the outcome of cataract surgeries in terms of restoration of visual function in the operated eye in Plateau State, Nigeria. Method: Four centres were selected using stratified random sampling technique. Consecutive patients, who had cataract extraction from 1st October 2002 - 31st March 2003, were ...

  7. Common Leg Aliment Of Poultry In Plateau State, Nigeria | Ogbe ...

    African Journals Online (AJOL)

    ... cockerels 17(18.68 %), guinea fowls 15(39.47 %) and ostriches2(5.26 %). Curled toes, mange, Newcastle disease, Mareks disease and Clostridia infections resulting in leg ailments were also observed. Keywords: Leg ailments, Poultry, Implication, Plateau State Animal Research International Vol. 1 (3) 2004 pp. 208-211 ...

  8. The structure of foam cells: isotropic plateau polyhedra

    NARCIS (Netherlands)

    Hilgenfeldt, Sascha; Kraynik, A.M.; Reinelt, D.A.; Sullivan, J.M.

    2004-01-01

    A mean-field theory for the geometry and diffusive growth rate of soap bubbles in dry 3D foams is presented. Idealized foam cells called isotropic Plateau polyhedra (IPPs), with F identical spherical-cap faces, are introduced. The geometric properties (e.g., surface area S, curvature R, edge length

  9. Eddy formation around South West Mascarene Plateau (Indian Ocean)

    African Journals Online (AJOL)

    Acoustic Doppler Current Profiler (ADCP) measurements undertaken through the hydrographic survey by RRS Charles Darwin in June-July 2002. They described these current systems as a 'northern and southern core', with the northern core passing through the Plateau in between Saya de Malha and. Nazareth Banks ...

  10. Deep mantle forces and the uplift of the Colorado Plateau

    Energy Technology Data Exchange (ETDEWEB)

    Moucha, R; Forte, A M; Rowley, D B; Mitrovica, J X; Simmons, N A; Grand, S P

    2009-06-23

    Since the advent of plate tectonics, it has been speculated that the northern extension of the East Pacific Rise, specifically its mantle source, has been over-ridden by the North American Plate in the last 30 Myrs. Consequently, it has also been postulated that the opening of the Gulf of California, the extension in the Basin and Range province, and the uplift of the Colorado Plateau are the resulting continental expressions of the over-ridden mantle source of the East Pacific Rise. However, only qualitative models based solely on surface observations and heuristic, simplified conceptions of mantle convection have been used in support or against this hypothesis. We introduce a quantitative model of mantle convection that reconstructs the detailed motion of a warm mantle upwelling over the last 30 Myrs and its relative advance towards the interior of the southwestern USA. The onset and evolution of the crustal uplift in the central Basin and Range province and the Colorado Plateau is determined by tracking the topographic swell due to this mantle upwelling through time. We show that (1) the extension and magmatism in the central Basin and Range province between 25 and 10 Ma coincides with the reconstructed past position of this focused upwelling, and (2) the southwestern portion of the Colorado Plateau experienced significant uplift between 10 Ma and 5 Ma that progressed towards the northeastern portion of the plateau. These uplift estimates are consistent with a young, ca. 6 Ma, Grand Canyon model and the recent commencement of mafic magmatism.

  11. Lateritic weathering of granite-gneiss in Obudu Plateau, south ...

    African Journals Online (AJOL)

    Obudu Plateau (Latitudes 60 30`N, 6045`N and Longitudes 9015`E, 10000`E) is a basement Horst bordered in the East by the Cameroun volcanic line, both of which form the Bamenda massif. This is a zone of migmatite-gneissschist complex with subordinate occurrence of amphibolites, charnockites and minor intrusive of ...

  12. Farmers' reason for going into poultry production in Plateau state ...

    African Journals Online (AJOL)

    Those in poultry production have reasons for going into the business. This study aimed at investigating the effect of the reasons for going into poultry production on the profit of poultry farmers in Plateau State. Random sampling technique was used to select 60 respondents from 4 Local Government Areas of the state.

  13. Is there seasonality in deliveries on the Plateau? | Daru | Tropical ...

    African Journals Online (AJOL)

    Objective- To determine if there are seasonal variations in delivery rates in JUTH, Jos, Plateau state, Nigeria Material and Methods- This is a retrospective descriptive study carried out in JUTH, Jos, Nigeria. The monthly delivery records from 1985-2011 (26 years) were extracted from the labour ward delivery record.

  14. Shade tolerance of selected afforestation species on Loess Plateau, China

    Science.gov (United States)

    Naijiang Wang; Yong Wang; Callie J. Schweitzer

    2011-01-01

    To select tree and vegetation species for afforestation on Loess Plateau of China, we tested the shade tolerance of nine tree and one vine species. We planted 3-year-old seedlings in the greenhouse of the Seedling Nursery at Northwest Agriculture and Forest University in China.

  15. Testicular torsion on the Jos Plateau | Ugwu | West African Journal ...

    African Journals Online (AJOL)

    Testicular pain, retraction and scrotal swelling were the most common presenting complaints. The highest incidence 65%) occurred between November and February when the weather on the Jos plateau is coldest. At surgery, 34 (60%) patients were found to have associated congenital anomalies; in 22 (39%) patients, the ...

  16. Geochemistry of Schists of Northwest Obudu Plateau, Southeastern ...

    African Journals Online (AJOL)

    Precambrian, highly foliated, fine – medium grained schists, which comprise migmatitic schist (MS), quartz mica schist (QMS), biotite mica schist (BMS) and hornblende biotite schist (HBS) constitute important lithological unit in Northwest Obudu Plateau. The schists are associated with gneisses, amphibolites and ...

  17. Checklist of Phytoplankton of Shendam Reserviour in Plateau State ...

    African Journals Online (AJOL)

    A qualitative study of phytoplankton flora was carried out in Shendam reservoir, Plateau state of Nigeria. Seventy one species were recorded indicating a fairly low species number when compared to other Nigerian waters. The major groups of phytoplankton found were chlorophyceae, bacilliarophyceae, cyanophyceae and ...

  18. An attempt to understand the observed plateau of the magnetization ...

    Indian Academy of Sciences (India)

    The next-nearest-neighbour (NNN) effect in tetranuclear iron(II) complexes of thiacalixarene macrocycles using the isotropic Heisenberg model has been investigated in order to understand its effects on the observed plateau of magnetization. Although NNN effect is generally very weak in these kinds of systems, it was ...

  19. Rainfall Erosivity Factor for Uasin Gishu Plateau, Kenya | Kariaga ...

    African Journals Online (AJOL)

    Runoff plots were established on bare soil classified as Dystric Nitosols (Typic Rhodudults) at Moi University Main Campus, on Uasin Gishu Plateau, Kenya. The objective of the study was to determine the best erosivity factor for the area. This was found to be EI30, defined as the product of the rainstorm's kinetic energy and ...

  20. Constraining the timing of Shillong Plateau uplift from a study of the palaeo-Brahmaputra deposits, Siwalik Group, Samdrup Jongkhar, Eastern Bhutan

    Science.gov (United States)

    Govin, G.; Najman, Y.; Grujic, D.; Van Der Beek, P.; Davenport, J.; Huyghe, P.

    2015-12-01

    The ~400 km long and two km high Shillong Plateau is the only major raised topography in the Himalayan foreland. Debates over the timing of uplift and implication for erosion-climate-tectonic couplings, strain partitioning within the Himalaya and the palaeodrainage history of the palaeo-Brahmaputra are important. Grujic et al, (2006) proposed that the uplift of the plateau has affected the exhumation of Himalayan rocks to the north in Bhutan, due to the creation of a regional climatic change in the plateau's rain shadow. By contrast, Coutand et al. (2014) suggest that the local decrease in erosion rates in the eastern Bhutan Himalaya is best explained by the decrease in overthrusting rates at 5-6 Ma, which might be potentially related to late Miocene to Pliocene changes in the India-southern Eurasia convergence partitioning, with shortening taken up by faults bounding the Shillong Plateau, i.e. by its uplift. The exhumation of the Shillong Plateau has been proposed to initiate by 8-15 Ma (Biswas et al, 2007; Clark & Bilham, 2008) whilst surface uplift, decoupled from exhumation, of Miocene (Chirouze et al 2013), Pliocene (Johnson and Nur Alam 1991; Biswas et al., 2007) and Early Quaternary (Najman et al, in review) have been proposed. Our study uses the foreland basin Siwalik sedimentary record preserved to the north of the Shillong Plateau in Bhutan, to constrain the plateau's uplift history. Provenance is characterized by U-Pb dating on detrital zircons, which allows specifically documenting an Indus-Yarlung suture-zone and therefore paleo-Brahmaputra signature. We document the timing that the palaeo-Brahmaputra was shunted north and west by the rising plateau, using this U/Pb provenance technique to detect first appearance of the river and to a minor degree the Namche Barwa syntaxe signature. The results allow to better constrain the period of uplifting of the Shillong Plateau and thus better inform the implications through a study of the palaeodrainage of the

  1. A Study about the Influence of Plateau Shear Line on Abnormal Precipitation in the Area to the East of the Tibetan Plateau

    Science.gov (United States)

    Xiao, T.; Wang, L.; Jia, L.; Chen, Y.

    2016-12-01

    Based on the activity characteristics of 571 Tibetan plateau shear line processes in 1998-2013, this paper studies the difference of circulation feature between the plateau shear line which has and has not moved out of the plateau area, and the relationship between it and plateau atmospheric low-frequency signal transmission,water vapor channel, energy transmission and conversion due to the influence of eastward-moving of plateau shear line on abnormal precipitation in Sichuan Basin. (1) The 571 plateau shear lines include 519 transverse shear lines and 52 vertical shear lines, of which 92 shear lines move out of the plateau area.Composite analysis discovered that the circulation feature of two-through and one-ridge type is in favor of moving-out of transverse plateau shear lines; the multiple fluctuations circulation type are in favor of moving-out of vertical plateau shear lines. Deepening of Baikal deep trough, weakening of high ridge before the deep trough, weakening of East Asia deep trough, invasion of warm advection and positive vorticity advection, western extension of subtropical high and reinforcement of south Asia high are all in favor of reinforcement and moving-out of vertical plateau shear lines. The Butterworth band-pass filtering signal shows that the plateau shear lines mainly appear in the place near peaks and troughs with zonal wind oscillatory for 30-60d. (2) By using HYSPLIT backward trajectory model to track the water vapor transmission path of precipitation in Sichuan Basin which is formed by eastward-moving of transverse plateau shear lines and vertical plateau shear lines, it shows that the influence of transverse plateau shear lines on the basin is from two water vapor channels,the influence of vertical plateau shear lines is from a channel. Plateau shear lines are different in water vapor convergence and and divergence and trajectory in different phases and at different altitudes. (3)the wave-packet propagation diagnosis shows that

  2. Dust emissions from unpaved roads on the Colorado Plateau

    Science.gov (United States)

    Duniway, M.; Flagg, C.; Belnap, J.

    2013-12-01

    On the Colorado Plateau, elevated levels of aeolian dust have become a major land management and policy concern due to its influence on climate, weather, terrestrial ecosystem dynamics, landscape development and fertility, melting of snow and ice, air quality, and human health. Most desert soil surfaces are stabilized by plants, rocks, and/or physical or biological soil crusts, but once disturbed, sediment production from these surfaces can increase dramatically. Road development and use is a common surface disturbing activity in the region. The extent and density of roads and road networks is rapidly increasing due to continued energy exploration, infrastructure development, and off-highway recreation activities. Though it is well known that unpaved roads produce dust, the relative contribution of dust from existing roads or the implications of future road development to regional dust loading is unknown. To address this need, we have initiated a multifaceted research effort to evaluating dust emissions from unpaved roads regionally. At 34 sites arranged across various road surfaces and soil textures in southeastern Utah, we are: 1) monitoring dust emissions, local wind conditions, and vehicle traffic and 2) evaluating fugitive dust potential using a portable wind tunnel and measuring road characteristics that affect dust production. We will then 3) develop a GIS-based model that integrates results from 1 & 2 to estimate potential dust contributions from current and future scenarios of regional road development. Passive, horizontal sediment traps were installed at three distances downwind from the road edge. One control trap was placed upwind of the samplers to account for local, non-road dust emissions. An electronic vehicle counter and anemometer were also installed at monitoring sites. Dust samples were collected every three months at fixed heights, 15 cm up to 100 cm above the soil surface, from March 2010 to the present. Threshold friction velocities (TFV

  3. New data on the structure of Permian-Triassic Complex of the Ustyurt Plateau, Uzbekistan

    Science.gov (United States)

    Krylov, N. A.; Grizik, A. Ya.

    2015-07-01

    The tectonic features of the Permian-Triassic Complex in the Ustyurt Plateau are considered on the basis of up-to-date seismic exploration methods against the background of a regional structural review. The peculiar structural style of the complex under consideration is characterized by the following attributes: the widespread Permian-Triassic faults that control block tectonics; the leading role of grabens various in morphology among negative paleostructures; the critical role of pre-Upper Permian rejuvenated faults in localization of grabens; the predominant extension of the Earth's crust during origin and development of grabens and subsequent shortening; the appearance of an inversion of the Permian-Triassic graben, deepest in region; the posthumous local uplifts formed in Permian-Triassic and Jurassic-Cenozoic. The morphological typification of graben-like paleotroughs of the transitional stage has been proposed. This stage predates typical platform regime at the young platforms.

  4. Erosion and deposition on the Pajarito Plateau, New Mexico, and implications for geomorphic responses to late Quaternary climatic changes

    Energy Technology Data Exchange (ETDEWEB)

    Reneau, S.L.; McDonald, E.V.; Gardner, J.N.; Longmire, P.A. [Los Alamos National Lab., NM (United States); Kolbe, T.R. [Woodward-Clyde Federal Services, Oakland, CA (United States); Carney, J.S. [Kent State Univ., OH (United States). Dept. of Geology; Watt, P.M. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Earth and Planetary Sciences

    1996-04-01

    The Pajarito Plateau of northern New Mexico contains a rich and diverse record of late Quaternary landscape changes in a variety of geomorphic settings that include gently-sloping mesa tops, steep canyon walls, and canyon bottoms. A broad range of investigations during the past decade, motivated by environmental and seismic hazard concerns, have resulted in examination of the characteristics, stratigraphy, and age of sediments and soils at numerous locations throughout the Plateau. Geochronologic control is provided by >140 radiocarbon dates supplemented by soil characterization and tephrochronology. In this paper we first summarize some of the results of recent and ongoing work on late Quaternary deposits on the Pajarito Plateau, illustrating both the complexity of the geomorphic record and some common elements that have been observed in multiple locations. We then use these observations, in combination with other work in the Southwest, to make some inferences about the local geomorphic response to regional climatic changes. Because the geomorphic and paleoclimatic records are fragmentary, and because the relations between large scale climate changes and local variations in precipitation, vegetation, and geomorphic processes are not fully understood, many uncertainties exist concerning the response of the local landscape to past climatic fluctuations. In addition, variations in local landscape sensitivity related to prior erosional history and spatial variations in vegetation, and the localized nature of many storms, probably contribute to the complexity of the geomorphic record. Nevertheless, the work discussed in this paper suggests a strong relation between regional climatic changes and local geomorphic history, and provides a framework for considering relations between modem processes, the record of past landscape changes, and future erosion and deposition on the Plateau and in surrounding areas.

  5. A late glacial and Holocene lake record from the eastern Tibetan Plateau and inferences of lake, glacier and climate evolution

    Science.gov (United States)

    Zhang, C.; Mischke, S.

    2008-12-01

    A 12.81 m sediment core from Lake Ximencuo provides insight into the late glacial and Holocene evolution of the lake and the Nianbaoyeze glacier in its catchment, and the regional climate history since ~19 ka. Lake Ximencuo was a permanent deep lake throughout its history. In contrast to numerous lakes on the Tibetan Plateau which experienced shallow lake levels or even desiccation during the late glacial, Lake Ximencuo was fed by large meltwater quantities in the late glacial. The existence of glaciated upper catchment areas seems to have been a prerequisite for lakes on the Tibetan Plateau which maintained relatively high water levels during the generally cold and dry period following the global LGM (~21 ka). A minor re-advance of the Nianbaoyeze glacier was recorded during the latter half of the Oldest Dryas (~16.4 and 14.5 ka), followed by rapid Bolling/Allerod warming. Most favourable conditions were recorded at Lake Ximencuo during the early Holocene which was punctured by a remarkable pulse of climate deterioration around 8.3 ka. This spell represents the 8.2 ka event of the North Atlantic region and proves that it had a significant impact on the Tibetan Plateau. Less favourable conditions of longer duration occurred from 4.7-3.7 ka, apparently in phase with numerous records signalling colder and drier conditions on the Tibetan Plateau. Two minor spells of less favourable conditions and probably catchment erosion were recorded in the late Holocene between 2.0 and 1.4 ka and between 0.5 and 0.1 ka with the latter representing the Little Ice Age. It remains open, whether human activities may have accelerated or even solely triggered the late Holocene erosion events.

  6. Reassessment of soil erosion on the Chinese loess plateau: were rates overestimated?

    Science.gov (United States)

    Zhao, Jianlin; Govers, Gerard

    2014-05-01

    Several studies have estimated regional soil erosion rates (rill and interrill erosion) on the Chinese loess plateau using an erosion model such as the RUSLE (e.g. Fu et al., 2011; Sun et al., 2013). However, the question may be asked whether such estimates are realistic: studies have shown that the use of models for large areas may lead to significant overestimations (Quinton et al., 2010). In this study, soil erosion rates on the Chinese loess plateau were reevaluated by using field measured soil erosion data from erosion plots (216 plots and 1380 plot years) in combination with a careful extrapolation procedure. Data analysis showed that the relationship between slope and erosion rate on arable land could be well described by erosion-slope relationships reported in the literature (Nearing, 1997). The increase of average erosion rate with slope length was clearly degressive, as could be expected from earlier research. However, for plots with permanent vegetation (grassland, shrub, forest) no relationship was found between erosion rates and slope gradient and/or slope length. This is important, as it implies that spatial variations of erosion on permanently vegetated areas cannot be modeled using topographical functions derived from observations on arable land. Application of relationships developed for arable land will lead to a significant overestimation of soil erosion rates. Based on our analysis we estimate the total soil erosion rate in the Chinese Loess plateau averages ca. 6.78 t ha-1 yr-1 for the whole loess plateau, resulting in a total sediment mobilisation of ca. 0.38 Gt yr-1. Erosion rates on arable land average ca. 15.10 t ha-1 yr-1. These estimates are 2 to 3 times lower than previously published estimates. The main reason why previous estimates are likely to be too high is that the values of (R)USLE parameters such as K, P and LS factor were overestimated. Overestimations of the K factor are due to the reliance of nomograph calculations, resulting

  7. The biogeography of soil archaeal communities on the eastern Tibetan Plateau

    Science.gov (United States)

    Shi, Yu; Adams, Jonathan M.; Ni, Yingying; Yang, Teng; Jing, Xin; Chen, Litong; He, Jin-Sheng; Chu, Haiyan

    2016-12-01

    The biogeographical distribution of soil bacterial communities has been widely investigated. However, there has been little study of the biogeography of soil archaeal communities on a regional scale. Here, using high-throughput sequencing, we characterized the archaeal communities of 94 soil samples across the eastern Tibetan Plateau. Thaumarchaeota was the predominant archael phylum in all the soils, and Halobacteria was dominant only in dry soils. Archaeal community composition was significantly correlated with soil moisture content and C:N ratio, and archaeal phylotype richness was negatively correlated with soil moisture content (r = -0.47, P < 0.01). Spatial distance, a potential measure of the legacy effect of evolutionary and dispersal factors, was less important than measured environmental factors in determining the broad scale archaeal community pattern. These results indicate that soil moisture and C:N ratio are the key factors structuring soil archaeal communities on the eastern Tibetan Plateau. Our findings suggest that archaeal communities have adjusted their distributions rapidly enough to reach range equilibrium in relation to past environmental changes e.g. in water availability and soil nutrient status. This responsiveness may allow better prediction of future responses of soil archaea to environmental change in these sensitive ecosystems.

  8. No evidence of widespread decline of snow cover on the Tibetan Plateau over 2000-2015.

    Science.gov (United States)

    Wang, Xiaoyue; Wu, Chaoyang; Wang, Huanjiong; Gonsamo, Alemu; Liu, Zhengjia

    2017-11-07

    Understanding the changes in snow cover is essential for biological and hydrological processes in the Tibetan Plateau (TP) and its surrounding areas. However, the changes in snow cover phenology over the TP have not been well documented. Using Moderate Resolution Imaging Spectroradiometer (MODIS) daily snow products and the Interactive Multi-sensor Snow and Ice Mapping System (IMS) data, we reported daily cloud-free snow cover product over the Tibetan Plateau (TP) for 2000-2015. Snow cover start (SCS), melt (SCM) and duration (SCD) dates were calculated for each hydrological year, and their spatial and temporal variations were analyzed with elevation variations. Our results show no widespread decline in snow cover over the past fifteen years and the trends of snow cover phenology over the TP has high spatial heterogeneity. Later SCS, earlier SCM, and thus decreased SCD mainly occurred in the areas with elevation below 3500 m a.s.l., while regions in central and southwestern edges of the TP showed advanced SCS, delayed SCM and consequently longer SCD. The roles of temperature and precipitation on snow cover penology varied in different elevation zones, and the impact of both temperature and precipitation strengthened as elevation increases.

  9. CSSP MESETA : Simulation of the East Asian Summer Monsoon with idealized Tibetan Plateau orography

    Science.gov (United States)

    Wong, Kai Chi; Turner, Andrew

    2017-04-01

    Contrary to the traditional view on monsoon dynamics, recent modelling studies have shown that orographic blocking from the Himalayas is perhaps more important than the elevated heating from the Tibetan Plateau (TP) in maintaining the South Asian summer monsoon (SASM). For the East Asian summer monsoon (EASM), the mechanism is less clear. The CSSP MESETA project aims to further investigate the TP's orographic forcing on the dynamic and thermodynamic structures of regional and downstream climate. Using the UK Met Office HadGEM3 model in its atmosphere only configuration, various experiments with idealised orography were performed to assess the orographic forcing exerted by the TP, Himalayas (HM) and Iranian Plateau (IP). Our results confirm that elevated heating from the TP is indeed not required to maintain the SASM while the HM and IP are both important in sheltering the Indian landmass from the cooler extratropical airmass. Meanwhile, the EASM weakens in all simulations that removed the TP. Whether this is due to the lack of elevated heating or orographic blocking will be the focus of future investigation. This work contributes to the goals of the Global Monsoon Model Intercomparison Project (GMMIP), an endorsed component of CMIP6.

  10. Origins of plateau formation in ion energy spectra under target normal sheath acceleration

    Science.gov (United States)

    DuBois, Timothy C.; Siminos, Evangelos; Ferri, Julien; Gremillet, Laurent; Fülöp, Tünde

    2017-12-01

    Target normal sheath acceleration (TNSA) is a method employed in laser-matter interaction experiments to accelerate light ions (usually protons). Laser setups with durations of a few 10 fs and relatively low intensity contrasts observe plateau regions in their ion energy spectra when shooting on thin foil targets with thicknesses of the order of 10 μm. In this paper, we identify a mechanism which explains this phenomenon using one-dimensional particle-in-cell simulations. Fast electrons generated from the laser interaction recirculate back and forth through the target, giving rise to time-oscillating charge and current densities at the target backside. Periodic decreases in the electron density lead to transient disruptions of the TNSA sheath field: peaks in the ion spectra form as a result, which are then spread in energy from a modified potential driven by further electron recirculation. The ratio between the laser pulse duration and the recirculation period (dependent on the target thickness, including the portion of the pre-plasma which is denser than the critical density) determines if a plateau forms in the energy spectra.

  11. A seven-million-year hornblende mineral record from the central Chinese Loess Plateau.

    Science.gov (United States)

    He, Tong; Liu, Lianwen; Chen, Yang; Sheng, Xuefen; Ji, Junfeng

    2017-05-24

    Previous studies of the late Cenozoic erosion rate have yielded different views-long-term stable rates or a significant increase at climate transitions-leading to uncertainty concerning the hypothesized global erosion rate controlled by either tectonic uplift or climatic changes. Here, we present a seven-million-year hornblende mineral record along the Lingtai section of the Chinese Loess Plateau. By examining the spatial distribution of hornblende minerals in seven desert basins, which are potential loess source areas, we constructed a ratio of hornblende versus total heavy minerals to reflect past changes in physical/chemical weathering strength. Our results demonstrate that the ratio has generally increased since 7 Ma, with three significant shifts recorded at 2.6 Ma, 1.4 Ma and 0.5 Ma linked to the onset, continuation and expansion of the Northern Hemisphere glaciation, respectively. Given that chemical weathering during the diagenetic history produces a trend of smoothly increasing hornblende migrating upwards, the three shifts at these boundaries can be interpreted as changes in the bedrock erosion rate on the northern Tibetan Plateau, which may be related to tectonic uplift events and incision of the Yellow River. Evidence presented here supports the idea of coupling between climate change, tectonic uplift and regional erosion.

  12. Evapotranspiration Trend and Its Relationship with Precipitation over the Loess Plateau during the Last Three Decades

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    Zesu Yang

    2016-01-01

    Full Text Available There have been few studies conducted on the changes in actual ET over the Loess Plateau, due to the lack of reliable ET data. Based on ET data simulated by the Community Land Model, the present study analyzed the changes in ET over the Loess Plateau. The results showed the domain-average ET to have decreased in the past 31 years, at a rate of 0.78 mm year−1. ET fluctuated much more strongly in the 1990s than in the 1980s and 2000s, and, apart from in autumn, ET decreased in all seasons. In particular, ET in summer comprised about half of the annual ET trend and had the sharpest trend, dominating the interannual decline. ET also decreased more sharply in the semiarid than semihumid regions. The declining trend of ET was attributed to declining precipitation and air humidity. Locally, the ET trend was closely related to local mean annual precipitation: in areas with precipitation less than 400 mm, ET showed a decreasing trend; in areas with precipitation larger than 600 mm, ET showed an increasing trend; and in areas with precipitation in the range of 400–600 mm could be classified as a transitional zone.

  13. Survival Rate of Short, Locking Taper Implants with a Plateau Design: A 5-Year Retrospective Study

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    Kemal Özgür Demiralp

    2015-01-01

    Full Text Available Background. Short implants have become popular in the reconstruction of jaws, especially in cases with limited bone height. Shorter implants, those with locking tapers and plateau root shapes, tend to have longer survival times. We retrospectively investigated the cumulative survival rates of Bicon short implants (<8 mm according to patient variables over a 5-year period. Materials and Methods. This study included 111 consecutively treated patients with 371 implants supporting fixed or removable prosthetics. Data were evaluated to acquire cumulative survival rates according to gender, age, tobacco use, surgical procedure, bone quality, and restoration type. Statistics were performed using chi-square, Mann-Whitney, and Kruskal Wallis H tests. Results. The survival rate was 97.3% with, on average, 22.8 months of follow-up. Patients older than 60 years had higher failure rate than the other age groups (P<0.05. Placed region, age, and bone quality had adverse effects on survival rate in the <8 mm implant group with statistically significant difference (P<0.05. Conclusions. Approximately 23-month follow-up data indicate that short implants with locking tapers and plateau-type roots have comparable survival rates as other types of dental implants. However, due to limitations of study, these issues remain to be further investigated in future randomized controlled clinical trials.

  14. Changes in vegetation phenology on the Mongolian Plateau and their climatic determinants.

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    Lijuan Miao

    Full Text Available Climate change affects the timing of phenological events, such as the start, end, and length of the growing season of vegetation. A better understanding of how the phenology responded to climatic determinants is important in order to better anticipate future climate-ecosystem interactions. We examined the changes of three phenological events for the Mongolian Plateau and their climatic determinants. To do so, we derived three phenological metrics from remotely sensed vegetation indices and associated these with climate data for the period of 1982 to 2011. The results suggested that the start of the growing season advanced by 0.10 days yr-1, the end was delayed by 0.11 days yr-1, and the length of the growing season expanded by 6.3 days during the period from 1982 to 2011. The delayed end and extended length of the growing season were observed consistently in grassland, forest, and shrubland, while the earlier start was only observed in grassland. Partial correlation analysis between the phenological events and the climate variables revealed that higher temperature was associated with an earlier start of the growing season, and both temperature and precipitation contributed to the later ending. Overall, our findings suggest that climate change will substantially alter the vegetation phenology in the grasslands of the Mongolian Plateau, and likely also in biomes with similar environmental conditions, such as other semi-arid steppe regions.

  15. Elevation Pattern in Growth Coherency on the Southeastern Tibetan Plateau

    Science.gov (United States)

    Lyu, Lixin; Deng, Xu; Zhang, Qi-Bin

    2016-01-01

    It is generally expected that inter-annual changes in radial growth among trees would be similar to the increase in altitude due to the limitation of increasingly harsher climatic factors. Here, we examine whether this pattern exists in alpine forests on the southeastern Tibetan Plateau. Increment cores were collected from mature trees at the lower, middle and upper limits of balfour spruce (Picea likiangensis var. balfouriana (Rehd. et Wils.) Hillier ex Slsvin) forests at the Buze and Yela Mountains in Basu County, Changdu Prefecture of Tibet, China. The treeline elevations are 4320 m and 4510 m a.s.l. for Buze and Yela, respectively. Tree-ring widths were measured, crossdated, and detrended to obtain a sequence of ring-width indices for each individual sample. Annual growth rate, climate sensitivity, growth-climate relationships, and growth synchrony among trees were calculated and compared across altitudes. In Buze Mountain, the annual growth rate of trees has no significant difference across altitudes. The mean sensitivity of trees is lower at the treelines than at lower elevations. Tree growth has stronger correlation with winter temperature at upper elevations than at lower elevations, has significant correlation with moisture, not temperature, in the growing season, and the growth response to moisture is lower at the treeline than at lower elevations. The correlation among individual tree-ring sequences is lower at the treeline than at sites at lower elevation. In Yela Mountain, the characterisitics of annual growth rate, mean sensitivity, tree growth-climate relationships, and inter-serial correlation are similar to those in Buze, but their differences along altitudinal gradients are less significant as those in Buze. Our data do not support the general expectation of growth convergence among individuals with increasing altitude. We conclude that individual heterogeneity and microhabitat diversity are important features for treeline trees that may dampen

  16. Elevation Pattern in Growth Coherency on the Southeastern Tibetan Plateau.

    Directory of Open Access Journals (Sweden)

    Lixin Lyu

    Full Text Available It is generally expected that inter-annual changes in radial growth among trees would be similar to the increase in altitude due to the limitation of increasingly harsher climatic factors. Here, we examine whether this pattern exists in alpine forests on the southeastern Tibetan Plateau. Increment cores were collected from mature trees at the lower, middle and upper limits of balfour spruce (Picea likiangensis var. balfouriana (Rehd. et Wils. Hillier ex Slsvin forests at the Buze and Yela Mountains in Basu County, Changdu Prefecture of Tibet, China. The treeline elevations are 4320 m and 4510 m a.s.l. for Buze and Yela, respectively. Tree-ring widths were measured, crossdated, and detrended to obtain a sequence of ring-width indices for each individual sample. Annual growth rate, climate sensitivity, growth-climate relationships, and growth synchrony among trees were calculated and compared across altitudes. In Buze Mountain, the annual growth rate of trees has no significant difference across altitudes. The mean sensitivity of trees is lower at the treelines than at lower elevations. Tree growth has stronger correlation with winter temperature at upper elevations than at lower elevations, has significant correlation with moisture, not temperature, in the growing season, and the growth response to moisture is lower at the treeline than at lower elevations. The correlation among individual tree-ring sequences is lower at the treeline than at sites at lower elevation. In Yela Mountain, the characterisitics of annual growth rate, mean sensitivity, tree growth-climate relationships, and inter-serial correlation are similar to those in Buze, but their differences along altitudinal gradients are less significant as those in Buze. Our data do not support the general expectation of growth convergence among individuals with increasing altitude. We conclude that individual heterogeneity and microhabitat diversity are important features for treeline trees

  17. Elevation Pattern in Growth Coherency on the Southeastern Tibetan Plateau.

    Science.gov (United States)

    Lyu, Lixin; Deng, Xu; Zhang, Qi-Bin

    It is generally expected that inter-annual changes in radial growth among trees would be similar to the increase in altitude due to the limitation of increasingly harsher climatic factors. Here, we examine whether this pattern exists in alpine forests on the southeastern Tibetan Plateau. Increment cores were collected from mature trees at the lower, middle and upper limits of balfour spruce (Picea likiangensis var. balfouriana (Rehd. et Wils.) Hillier ex Slsvin) forests at the Buze and Yela Mountains in Basu County, Changdu Prefecture of Tibet, China. The treeline elevations are 4320 m and 4510 m a.s.l. for Buze and Yela, respectively. Tree-ring widths were measured, crossdated, and detrended to obtain a sequence of ring-width indices for each individual sample. Annual growth rate, climate sensitivity, growth-climate relationships, and growth synchrony among trees were calculated and compared across altitudes. In Buze Mountain, the annual growth rate of trees has no significant difference across altitudes. The mean sensitivity of trees is lower at the treelines than at lower elevations. Tree growth has stronger correlation with winter temperature at upper elevations than at lower elevations, has significant correlation with moisture, not temperature, in the growing season, and the growth response to moisture is lower at the treeline than at lower elevations. The correlation among individual tree-ring sequences is lower at the treeline than at sites at lower elevation. In Yela Mountain, the characterisitics of annual growth rate, mean sensitivity, tree growth-climate relationships, and inter-serial correlation are similar to those in Buze, but their differences along altitudinal gradients are less significant as those in Buze. Our data do not support the general expectation of growth convergence among individuals with increasing altitude. We conclude that individual heterogeneity and microhabitat diversity are important features for treeline trees that may dampen

  18. Shiga Toxin-Producing Escherichia coli in Plateau Pika (Ochotona curzoniae on the Qinghai-Tibetan Plateau, China

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    Xiangning eBAI

    2016-03-01

    Full Text Available Shiga toxin-producing Escherichia coli (STEC are an emerging group of zoonotic pathogens. Ruminants are the natural reservoir of STEC. In this study we determined the prevalence and characteristics of the STEC in plateau pika (Ochotona curzoniae on the Qinghai-Tibetan Plateau, China. A total of 1116 pika samples, including 294 intestinal contents samples, 317 fecal samples, and 505 intestinal contents samples, were collected from May to August in the years 2012, 2013 and 2015, respectively. Twenty-one samples (1.88% yielded at least one STEC isolate; in total, 22 STEC isolates were recovered. Thirteen different O serogroups and 14 serotypes were identified. One stx1 subtype (stx1a and three stx2 subtypes (stx2a, stx2b and stx2d were present in the STEC isolates. Fifteen, fourteen and three STEC isolates harbored the virulence genes ehxA, subA, and astA, respectively. Adherence-associated genes iha and saa were respectively present in 72.73% and 68.18% of the STEC isolates. Twenty antibiotics were active against all the STEC isolates; all strains were resistant to penicillin G, and some to cephalothin or streptomycin. The 22 STEC isolates were divided into 16 PFGE patterns and 12 sequence types. Plateau pikas may play a role in the ongoing circulation of STEC in the Qinghai-Tibetan plateau. This study provides the first report on STEC in plateau pikas and new information about STEC reservoirs in wildlife. Based on the serotypes, virulence gene profiles and MLST analysis, the majority of these pika STECs may pose a low public health risk.

  19. Groundwater storage changes in the Tibetan Plateau and adjacent areas revealed from GRACE satellite gravity data

    Science.gov (United States)

    Xiang, Longwei; Wang, Hansheng; Steffen, Holger; Wu, Patrick; Jia, Lulu; Jiang, Liming; Shen, Qiang

    2016-09-01

    Understanding groundwater storage (GWS) changes is vital to the utilization and control of water resources in the Tibetan Plateau. However, well level observations are rare in this big area, and reliable hydrology models including GWS are not available. We use hydro-geodesy to quantitate GWS changes in the Tibetan Plateau and surroundings from 2003 to 2009 using a combined analysis of satellite gravity and satellite altimetry data, hydrology models as well as a model of glacial isostatic adjustment (GIA). Release-5 GRACE gravity data are jointly used in a mascon fitting method to estimate the terrestrial water storage (TWS) changes during the period, from which the hydrology contributions and the GIA effects are effectively deducted to give the estimates of GWS changes for 12 selected regions of interest. The hydrology contributions are carefully calculated from glaciers and lakes by ICESat-1 satellite altimetry data, permafrost degradation by an Active-Layer Depth (ALD) model, soil moisture and snow water equivalent by multiple hydrology models, and the GIA effects are calculated with the new ICE-6G_C (VM5a) model. Taking into account the measurement errors and the variability of the models, the uncertainties are rigorously estimated for the TWS changes, the hydrology contributions (including GWS changes) and the GIA effect. For the first time, we show explicitly separated GWS changes in the Tibetan Plateau and adjacent areas except for those to the south of the Himalayas. We find increasing trend rates for eight basins: + 2.46 ± 2.24 Gt/yr for the Jinsha River basin, + 1.77 ± 2.09 Gt/yr for the Nujiang-Lancangjiang Rivers Source Region, + 1.86 ± 1.69 Gt/yr for the Yangtze River Source Region, + 1.14 ± 1.39 Gt/yr for the Yellow River Source Region, + 1.52 ± 0.95 Gt/yr for the Qaidam basin, + 1.66 ± 1.52 Gt/yr for the central Qiangtang Nature Reserve, + 5.37 ± 2.17 Gt/yr for the Upper Indus basin and + 2.77 ± 0.99 Gt/yr for the Aksu River basin. All these

  20. Exploring the undulating plateau: the future of global oil supply.

    Science.gov (United States)

    Jackson, Peter M; Smith, Leta K

    2014-01-13

    In this paper, we analyse the factors that will influence long-term oil supply and describe the future form of the global oil supply profile as an 'undulating plateau' rather than an irreversible, short-term peak or an ever upward trend of increasing production. The ultimate transition from a world of relatively plentiful and cheap oil to one of tight supply and high cost will be slow and challenging. An understanding of the signposts for the future path of supply and the drivers of that profile will be critical to managing the transition. The ultimate form of the global supply curve may well be dictated by demand evolution rather than a limited resource endowment in the longer term. Several factors will probably control future global oil supply. We believe that the scale of global oil resource will not constitute a physical supply limit for at least the next two or three decades. However, all categories of oil resources are already more expensive to develop than in the past, requiring high oil prices to stimulate supply growth. Lower rates of oil demand growth relative to economic growth, combined with more challenging supply growth, will probably lead to an undulating plateau sometime after 2040, with demand from non-Organization for Economic Cooperation and Development states continuing to dominate. Upstream investment requirements and oil price volatility will increase towards and beyond the undulating production plateau. In this new world, high oil prices will induce demand destruction, fuel substitution and ever increasing energy efficiency. As we discuss below, the fundamental differences between the IHS Cambridge Energy Research Associates' (IHS CERA) view of the future of oil supply and many peak oil supply models are the timing of the onset of a dramatic slowdown in the rate of growth of supply and the existence or otherwise of a production plateau. We do not dispute that supply will plateau and eventually fall; the question is when, how and at what price

  1. [The epidemiology and etiology research of Tibetan sheep plague in Qinghai plateau].

    Science.gov (United States)

    Wei, Baiqing; Xiong, Haoming; Yang, Xiaoyan; Yang, Yonghai; Qi, Meiying; Jin, Juan; Xin, Youquan; Li, Xiang; Yang, Hanqing; Han, Xiumin; Dai, Ruixia

    2015-03-01

    To identify the epidemiology and etiology characteristics of Tibetan sheep plague in Qinghai plateau. The background materials of Qinghai Tibetan sheep plague found during 1975 to 2009 were summarized, the regional, time and interpersonal distribution, infection routes, ecological factors for the spread were used to analyze; followed by choosing 14 Yersinia pestis strains isolated from such sheep for biochemical test, toxicity test, virulence factors identification, plasmid analysis, and DFR genotype. From 1975 to 2009, 14 Yersinia pestis strains were isolated from Tibetan sheep in Qinghai province. Tibetan sheep, as the infection source, had caused 10 cases of human plague, 25 plague patients, and 13 cases of death. All of the initial cases were infected due to eating Tibetan sheep died of plague; followed by cases due to contact of plague patients, while all the initial cases were bubonic plague. Cases of bubonic plague developed into secondary pneumonic plague and septicemia plague were most popular and with high mortality. Most of the Tibetan sheep plague and human plague occurred in Gannan ecological zone in southern Gansu province, which was closely related to its unique ecological and geographical landscape. Tibetan sheep plague coincided with human plague caused by Tibetan sheep, especially noteworthy was that November (a time for marmots to start their dormancy) witnesses the number of Yersinia pestis strains isolated from Tibetan sheep and human plague cases caused by Tibetan sheep. This constituted the underlying cause that the epidemic time of Tibetan sheep plague lags obviously behind that of the Marmot plague. It was confirmed in the study that all the 14 strains were of Qinghai-Tibet Plateau ecotype, with virulence factors evaluation and toxicity test demonstrating strains as velogenic. As found in the (Different Region) DFR genotyping, the strains isolated from Yushu county and Zhiduo county were genomovar 5, the two strain isolated from Nangqian

  2. GIS-Based Synthetic Measurement of Sustainable Development in Loess Plateau Ecologically Fragile Area—Case of Qingyang, China

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    Chenyu Lu

    2015-02-01

    Full Text Available Synthetic measurement of regional sustainable development has been one of the key issues in the research field of sustainability. In this paper, Qingyang City located in the Loess Plateau ecologically fragile area of Northwest China is used for a case study, and the present study aims to investigate the degree of sustainable development by conducting temporal- and spatial-scale based analysis, with the assessment index system, assessment model and GIS approach well integrated. The results show that the development pattern of Qingyang generally fits the mode of unsustainable development, even in the presence of certain levels of spatial differences. The sustainable development state in ecologically fragile area of China’s Loess Plateau is non-optimistic, which is an uncoordinated status among subsystems of regional sustainable development. Although the level and tendency of regional sustainable development keeps increasing, such enhancement is abnormal. With the rapid deterioration of environmental and natural resources, their inhibitory effect on the economy and society would expand, eventually leading to the slow development rate or the recession of the entire system. The only solution is to change the traditional mode of economic development, to follow the guide of ecological economic conception so that the goal of achieving regional sustainable development strategies could be met ultimately. Meanwhile, the characteristics of different regions should be taken into account in order to achieve optimal spatial structure.

  3. Evidence for an abrupt climatic reversal during the Last Interglacial on the northeast Qinghai-Tibetan Plateau

    NARCIS (Netherlands)

    Lu, H.; Vandenberghe, J.; Miao, X.; Tan, H.; Ma, H.

    2006-01-01

    Climatic change over Qinghai-Tibetan Plateau is controlled by alternation of the plateau summer and winter monsoon circulation, which is triggered by thermodynamic and kinetic effects of the high plateau morphology. Loess-paleosol sequences in northeast Qinghai-Tibetan Plateau are investigated to

  4. Constrasting styles of erosion along the western slope of the Central Andean Plateau

    Science.gov (United States)

    Hoke, G. D.; Isacks, B. L.; Jordan, T. E.

    2002-12-01

    We examine the western slope of the central Andes Mountains between 17S and 30S in an effort to elucidate the effects of along strike climate variability on landscape process and form. This region is most opportune for study because the mountain front is, to a first order, a relatively simple monoclinal structure and several lines of evidence point towards the general stability of today's observed climatic zones since 15 Ma. In the central part of the study region (22-25S), relict landscape preservation is extremely good, much of the relict middle Miocene surface (erosional and depositional) between 18S and 25S remains intact. This surface becomes progressively more dissected moving north and south of the central segment. We present data from satellite imagery and geomorphic analyses of a 90 m digital elevation model, which suggest that three independent erosion styles exist in the study area (excluding the central region where no significant rivers exist). The first order differences in erosional style are accounted for predominantly by where precipitation is falling. In southern Peru and northern Chile, almost all moisture is in the form of high elevation, easterly-sourced precipitation falling on the Altiplano Plateau and Western Cordillera. This results in groundwater controlled drainage networks in northern Chile and the existence of a large active salar, the Salar de Atacama, which apparently has trapped groundwater originating from the plateau. Available geologic evidence shows that these features are of greater antiquity than the Pleistocene glacial period in the Central Andes. South of 27S, westerly derived, orographically enhanced precipitation falls directly on the mountain front producing an erosional regime more typical of actively eroding mountain fronts.

  5. Provenance of the upper Miocene-Pliocene Red Clay deposits of the Chinese loess plateau

    Science.gov (United States)

    Nie, Junsheng; Peng, Wenbin; Möller, Andreas; Song, Yougui; Stockli, Daniel F.; Stevens, Thomas; Horton, Brian K.; Liu, Shanpin; Bird, Anna; Oalmann, Jeffrey; Gong, Hujun; Fang, Xiaomin

    2014-12-01

    A clear understanding of the provenance of late Cenozoic Chinese loess and the underlying Red Clay deposits will shed light on the history and mechanisms of Asian aridification. Although much progress has been made in understanding the source of Quaternary loess on the Chinese Loess Plateau (CLP), the provenance of the underlying upper Miocene-Pliocene Red Clay sequence is largely unknown. Here we present the first provenance history of the Red Clay sequence based on zircon U-Pb ages from the central CLP. Visual and statistical analyses of the U-Pb age populations and comparison with results from potential source regions reveals that (1) the lowermost Red Clay of the late Miocene (depositional age of ∼8 Ma) is likely sourced from the nearby Liupan Mountains and the Qaidam Basin; (2) the middle Red Clay (5.5-4 Ma) of the early-mid Pliocene is sourced mainly from the Taklamakan desert, transported via lower-level westerly winds; (3) the upper Red Clay of the late Pliocene (∼3 Ma) is sourced from mixed areas, although western source materials from middle-northern Tibetan plateau (including Qaidam Desert sediments and materials eroded from the Qilian Mountains) sediments appear to dominate; and (4) the Quaternary loess is also sourced from mixed source regions, albeit with dominant northern CLP proximal desert sediments transported via winter monsoon winds, which in turn may be transported from mountain source regions of the northeastern Tibet and Gobi Altai via major river systems. This long term shift in sources suggests a progressive eastward aridification during the Pliocene in Asia with the specific timing of provenance shifts synchronous with large-scale climatic transitions and Tibetan uplift, demonstrating that Asian desertification is controlled by both factors.

  6. Atmospheric brown clouds reach the Tibetan Plateau by crossing the Himalayas

    Directory of Open Access Journals (Sweden)

    Z. L. Lüthi

    2015-06-01

    Full Text Available The Himalayas and the Tibetan Plateau region (HTP, despite being a remote and sparsely populated area, is regularly exposed to polluted air masses with significant amounts of aerosols including black carbon. These dark, light-absorbing particles are known to exert a great melting potential on mountain cryospheric reservoirs through albedo reduction and radiative forcing. This study combines ground-based and satellite remote sensing data to identify a severe aerosol pollution episode observed simultaneously in central Tibet and on the southern side of the Himalayas during 13–19 March 2009 (pre-monsoon. Trajectory calculations based on the high-resolution numerical weather prediction model COSMO are used to locate the source regions and study the mechanisms of pollution transport in the complex topography of the HTP. We detail how polluted air masses from an atmospheric brown cloud (ABC over South Asia reach the Tibetan Plateau within a few days. Lifting and advection of polluted air masses over the great mountain range is enabled by a combination of synoptic-scale and local meteorological processes. During the days prior to the event, winds over the Indo-Gangetic Plain (IGP are generally weak at lower levels, allowing for accumulation of pollutants and thus the formation of ABCs. The subsequent passing of synoptic-scale troughs leads to southwesterly flow in the middle troposphere over northern and central India, carrying the polluted air masses across the Himalayas. As the IGP is known to be a hotspot of ABCs, the cross-Himalayan transport of polluted air masses may have serious implications for the cryosphere in the HTP and impact climate on regional to global scales. Since the current study focuses on one particularly strong pollution episode, quantifying the frequency and magnitude of similar events in a climatological study is required to assess the total impact.

  7. Alpine grassland fPAR change over the Northern Tibetan Plateau from 2002 to 2011

    Directory of Open Access Journals (Sweden)

    Bao-Xiong Chen

    2017-06-01

    Full Text Available In this study, two different methods including Digital Camera and Reference Panel (DCRP and traditional in situ fPAR observation for measuring the in situ point fPAR of very short alpine grass vegetation were compared, and the Moderate Resolution Imaging Spectroradiometer (MODIS fPAR products were evaluated and validated by in situ point data on the alpine grassland over the Northern Tibetan Plateau, which is sensitive to climate change and vulnerable to anthropogenic activities. Results showed that the MODIS alpine grassland fPAR product, examined by using DCRP, and traditional in situ fPAR observation had a significant relationship at the spatial and temporal scales. The decadal MODIS fPAR trend analysis showed that, average growing season fPAR increased by 1.2 × 10−4 per year and in total increased 0.86% from 2002 to 2011 in alpine grassland, when most of the fPAR increments occurred in southeast and center of the Northern Tibetan Plateau, the alpine grassland tended to recover from degradation slightly. However, climatic factors have influenced the various alpine grassland vegetation fPAR over a period of 10 years; precipitation significantly affected the alpine meadow fPAR in the eastern region, whereas temperature considerably influenced the alpine desert steppe fPAR in the west region. These findings suggest that the regional heterogeneity in alpine grassland fPAR results from various environmental factors, except for vegetation characteristics, such as canopy structure and leaf area.

  8. The permafrost carbon inventory on the Tibetan Plateau: a new evaluation using deep sediment cores

    Science.gov (United States)

    Yang, Y.; Ding, J.; Li, F.; Yang, G.; Chen, L.

    2016-12-01

    The permafrost organic carbon (OC) stock is of global significance because of its large pool size and potential positive feedback to climate warming. However, due to the lack of systematic field observations and appropriate upscaling methodologies, substantial uncertainties exist in the permafrost OC budget, which limits our understanding on the fate of frozen carbon in a warming world. In particular, the lack of comprehensive estimation of OC stock across alpine permafrost means that the current knowledge on this issue remains incomplete. Here we evaluated the pool size and spatial variations of permafrost OC stock to 3 meters depth on the Tibetan Plateau by combining systematic measurements from a substantial number of pedons (i.e., 342 three-meter-deep cores and 177 50-cm-deep pits) with a machine learning technique (i.e., support vector machine, SVM). We also quantified uncertainties in permafrost carbon budget by conducting Monte Carlo simulation. Our results revealed that the combination of systematic measurements with the SVM model allowed spatially explicit estimates. The OC density (OC amount per unit area, OCD) exhibited a decreasing trend from the southeastern to the northwestern plateau, with the exception that OCD in the swamp meadow was substantially higher than that in surrounding regions. Our results also demonstrated that Tibetan permafrost stored a large amount of OC in the top 3 meters, with the median OC pool size being 15.31 Pg C (interquartile range: 13.03-17.77 Pg C). Of them, 44% occurred in deep layers (i.e., 100-300 cm), close to the proportion observed across the northern circumpolar permafrost region. The large carbon pool size, together with significant permafrost thawing implies a risk of carbon emissions and positive climate feedback across the Tibetan alpine permafrost region.

  9. Variations in Vegetation Net Primary Production in the Qinghai-Xizang Plateau, China, from 1982 to 1999

    Energy Technology Data Exchange (ETDEWEB)

    Piao, S.; Fang, J.; He, J. [Department of Ecology, College of Environmental Science, and Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing, 100871 (China)

    2006-01-15

    Vegetation net primary production (NPP) derived from a carbon model (Carnegie-Ames-Stanford Approach, CASA) and its interannual change in the Qinghai-Xizang (Tibetan) Plateau were investigated in this study using 1982-1999 time series data sets of normalized difference vegetation index (NDVI) and paired ground-based information on vegetation, climate, soil, and solar radiation. The 18-year averaged annual NPP over the plateau was 125 g C m-2 yr-1, decreasing from the southeast to the northwest, consistent with precipitation and temperature patterns. Total annual NPP was estimated between 0.183 and 0.244 Pg C over the 18 years, with an average of 0.212 Pg C (1 Pg = 1015 g). Two distinct periods (1982-1990 and 1991-1999) of NPP variation were observed, separated by a sharp reduction during 1990-1991. From 1982 to 1990, annual NPP did not show a significant trend, while from 1991 to 1999 a marked increase of 0.007 Pg C yr-2 was observed. NPP trends for most vegetation types resembled that of the whole plateau. The largest annual NPP increase during 1991-1999 appeared in alpine meadows, accounting for 32.3% of the increment of the whole region. Changes in solar radiation and temperature significantly influenced NPP variation, suggesting that solar radiation may be one of the major factors associated with changes in NPP.

  10. Roots of forbs sense climate fluctuations in the semi-arid Loess Plateau: Herb-chronology based analysis.

    Science.gov (United States)

    Shi, Songlin; Li, Zongshan; Wang, Hao; von Arx, Georg; Lü, Yihe; Wu, Xing; Wang, Xiaochun; Liu, Guohua; Fu, Bojie

    2016-06-21

    Growth of herbaceous plants responds sensitively and rapidly to climate variability. Yet, little is known regarding how climate warming influences the growth of herbaceous plants, particularly in semi-arid sites. This contrasts with widely reported tree growth decline and even mortality in response to severe water deficits due to climate warming around the world. Here, we use the relatively novel approach of herb-chronology to analyze the correlation between climatic factors and annual ring width in the root xylem of two perennial forb species (Medicago sativa, Potentilla chinensis) in the Loess Plateau of China. We show that warming-induced water deficit has a significant negative effect on the growth of herbaceous plants in the Loess Plateau. Our results indicate that the growth of forbs responds rapidly and sensitively to drought variability, implying that water availability plays a dominant role in regulating the growth of herbaceous plants in semi-arid areas. If warming and drying in the Loess Plateau continue in the future, further affects the growth of herbaceous plants, potentially driving regional changes in the relationship between herbaceous vegetation and climate.

  11. Termination of fluvial-alluvial sedimentation in the Xining Basin, NE Tibetan Plateau, and its subsequent geomorphic evolution

    Science.gov (United States)

    Weilin, Zhang; Tao, Zhang; Chunhui, Song; Appel, Erwin; Ziqiang, Mao; Yahui, Fang; Yin, Lu; Qingquan, Meng; Rongsheng, Yang; Dawen, Zhang; Bingshuai, Li; Jiao, Li

    2017-11-01

    The Xining Basin in northern China lies topographically in the transitional zone between the Tibetan Plateau and the Loess Plateau, and climatically in the transitional zone between humid East Asia and the arid Asian interior. During the Cenozoic, the basin accumulated a thick, continuous sequence of fluviolacustrine-dominated red beds and subsequent eolian loess. The termination of sediment deposition in the Xining Basin is the key to understanding its subsequent evolution, the development of the modern Yellow River, and the history of dust deposition. Here we present the results of a detailed paleomagnetic study of the upper sedimentary sequence of the Xining Basin below the river terraces, and in addition we review previous studies of river evolution development. Our results indicate that the age of the uppermost part of the continuous sequence of fluviolacustrine-dominated red beds in the Xining Basin ranges from ca. 20 Ma to 4.8 Ma, suggesting that basin sedimentation ended at the earliest at 4.8 Ma, and they also provide an earliest age constraint for the subsequent river terrace development and eolian dust deposition. In addition, these results demonstrate that the termination of sedimentation in the Xining Basin and the nearby Linxia Basin was approximately coeval, suggesting the rapid regional tectonic uplift of the NE Tibetan Plateau and resulting reorganization of the landforms and development of the paleo-Yellow River in the late Pliocene.

  12. “Grain for Green” driven land use change and carbon sequestration on the Loess Plateau, China

    Science.gov (United States)

    Deng, Lei; Shangguan, Zhou-ping; Sweeney, Sandra

    2014-01-01

    Land-use change is widely considered to be a major factor affecting soil carbon (C) sequestration (ΔCs). This paper studied changes to soil C stocks (Cs) following the conversion of farmland to forest, shrub and grassland across the key area for implementing China's “Grain for Green” — the Loess Plateau. The results are based on a synthesis of 44 recent publications (including 424 observations at 70 sites) which has allowed us to further refine our understanding of the mechanisms driving the increase in Cs following farmland conversion. This synthesis suggests that the ΔCs potential of the Loess Plateau could reach 0.59 Tg yr−1 based on an estimated annual average ΔCs rate of 0.29 Mg ha−1 yr−1. In the region's different rainfall zones both the main contributing factors and Cs dynamics varied. Across the entire Loess Plateau, Cs showed first an increasing (10 yr) yet again. In addition, the ΔCs rates depended primarily on restoration age. This synthesis demonstrates that both the initial s Cs and the average annual temperature have a significant effect on ΔCs while the effect of land-use conversion type, rainfall zone, and average annual precipitation were minimal. PMID:25391219

  13. Tectonic Uplift vs. Climatic Change Controlled Denudation: Evidence from Synthesized Basin and Thermochronology of the NE Tibetan Plateau

    Science.gov (United States)

    Fang, X.; Song, C.; Yan, M.; Zhang, T.; Zhang, W.

    2016-12-01

    Denudation history and its driving forces are crucial to understand the roles of tectonics and climate, especially the role of the Tibetan Plateau in global weathering and climate change. However, it is very hard to distinguish each role of tectonics and climate. Here we reviewed and synthesized Cenozoic denudation and tectonic deformation and uplift histories of the NE Tibetan Plateau from detailed basin analyses and thermochronology. A simultaneous increase of sedimentation rate in all reviewed basins in the NE Tibetan Plateau is regarded as denudation event. Nine denudation events occurring at about 46-40Ma, 36-30Ma, 28-27Ma, 24-21Ma, 19-17Ma, 14-12Ma, 10-6Ma and 4-1Ma were found. These events, except those at 28-27Ma and 19-17Ma, are all synchronous in tectonic time scale with rapid cooling (denudation) events revealed by fission tract and U-Th/He dates of apatite grains in basin sediments and mountain rocks at different heights. We compare these denudation events with the tectonic uplift events summarized from occurrences of unconformity and growth strata and the rotation and shortening of basin and the global and regional climate records. It is found that the denudation events all match tectonic events, rather than climatic records. Therefore, we argue that tectonic uplift rather than climate places a major role in controlling mountain denudation.

  14. Roots of forbs sense climate fluctuations in the semi-arid Loess Plateau: Herb-chronology based analysis

    Science.gov (United States)

    Shi, S.

    2016-12-01

    Growth of herbaceous plants responds sensitively and rapidly to climate variability. Yet, little is known regarding how climate warming influences the growth of herbaceous plants, particularly in semi-arid sites. This contrasts with widely reported tree growth decline and even mortality in response to severe water deficits due to climate warming around the world. Here, we use the relatively novel approach of herb-chronology to analyze the correlation between climatic factors and annual ring width in the root xylem of two perennial forb species (Medicago sativa, Potentilla chinensis) in the Loess Plateau of China. We show that warming-induced water deficit has a significant negative effect on the growth of herbaceous plants in the Loess Plateau. Our results indicate that the growth of forbs responds rapidly and sensitively to drought variability, implying that water availability plays a dominant role in regulating the growth of herbaceous plants in semi-arid areas. If warming and drying in the Loess Plateau continue in the future, further affects the growth of herbaceous plants, potentially driving regional changes in the relationship between herbaceous vegetation and climate.

  15. Variations in extreme precipitation on the Loess Plateau using a high-resolution dataset and their linkages with atmospheric circulation indices

    Science.gov (United States)

    Zhao, Guangju; Zhai, Jianqing; Tian, Peng; Zhang, Limei; Mu, Xingmin; An, Zhengfeng; Han, Mengwei

    2017-08-01

    Assessing regional patterns and trends in extreme precipitation is crucial for facilitating flood control and drought adaptation because extreme climate events have more damaging impacts on society and ecosystems than simple shifts in the mean values. In this study, we employed daily precipitation data from 231 climate stations spanning 1961 to 2014 to explore the changes in precipitation extremes on the Loess Plateau, China. Nine of the 12 extreme precipitation indices suggested decreasing trends, and only the annual total wet-day precipitation (PRCPTOT) and R10 declined significantly: - 0.69 mm/a and - 0.023 days/a at the 95% confidence level. The spatial patterns in all of the extreme precipitation indices indicated mixed trends on the Loess Plateau, with decreasing trends in the precipitation extremes at the majority of the stations examined in the Fen-Wei River valley and high-plain plateau. Most of extreme precipitation indices suggested apparent regional differences, whereas R25 and R20 had spatially similar patterns on the Loess Plateau, with many stations revealing no trends. In addition, we found a potential decreasing trend in rainfall amounts and rainy days and increasing trends in rainfall intensities and storm frequencies in some regions due to increasing precipitation events in recent years. The relationships between extreme rainfall events and atmospheric circulation indices suggest that the weakening trend in the East Asia summer monsoon has limited the northward extension of the rainfall belt to northern China, thereby leading to a decrease in rainfall on the Loess Plateau.

  16. Are the Columbia River Basalts, Columbia Plateau, Idaho, Oregon, and Washington, USA, a viable geothermal target? A preliminary analysis

    Science.gov (United States)

    Burns, Erick R.; Williams, Colin F.; Tolan, Terry; Kaven, Joern Ole

    2016-01-01

    The successful development of a geothermal electric power generation facility relies on (1) the identification of sufficiently high temperatures at an economically viable depth and (2) the existence of or potential to create and maintain a permeable zone (permeability >10-14 m2) of sufficient size to allow efficient long-term extraction of heat from the reservoir host rock. If both occur at depth under the Columbia Plateau, development of geothermal resources there has the potential to expand both the magnitude and spatial extent of geothermal energy production. However, a number of scientific and technical issues must be resolved in order to evaluate the likelihood that the Columbia River Basalts, or deeper geologic units under the Columbia Plateau, are viable geothermal targets.Recent research has demonstrated that heat flow beneath the Columbia Plateau Regional Aquifer System may be higher than previously measured in relatively shallow (10-14 m2) interflows are documented at depths up to ~1,400 m. If the elevated permeability in these zones persists to greater depths, they may provide natural permeability of sufficient magnitude to allow their exploitation as conventional geothermal reservoirs. Alternatively, if the permeability in these interflow zones is less than 10-14 m2 at depth, it may be possible to use hydraulic and thermal stimulation to enhance the permeability of both the interflow zones and the natural jointing within the low-permeability interior portions of individual basalt flows in order to develop Enhanced/Engineered Geothermal System (EGS) reservoirs. The key challenge for an improved Columbia Plateau geothermal assessment is acquiring and interpreting comprehensive field data that can provide quantitative constraints on the recovery of heat from the Columbia River Basalts at depths greater than those currently tested by deep boreholes.

  17. Phylogeography of Cephalotaxus oliveri (Cephalotaxaceae) in relation to habitat heterogeneity, physical barriers and the uplift of the Yungui Plateau.

    Science.gov (United States)

    Wang, C B; Wang, T; Su, Y J

    2014-11-01

    Habitat heterogeneity, physical barriers, and the uplift of the Yungui Plateau were found to deeply affect the phylogeographic pattern and evolutionary history of Cephalotaxus oliveri, a perennial conifer endemic to China. In this study, we explored the phylogeography using three chloroplast sequences (trnL-trnF, trnT-trnD and atpB-rbcL) in 22 natural populations of C. oliveri distributed throughout its range. The Yungui Plateau populations of C. oliveri were revealed to origin ca. 9.15Ma by molecular clock estimation, which is consistent with rapid uplift of the Qinghai-Tibetan Plateau (QTP) ca. 8-10Ma. Additionally, geological effects of the Yungui Plateau were suggested to promote the rapid intra-specific differentiation of C. oliveri in the Pliocene and Early Pleistocene. The relatively low level of genetic diversity (h=0.719, θ=1.17×10(-3)) and high population differentiation (NST=0.771 and GST=0.642) implied restricted gene flow among populations, which was confirmed by the Nested Clade Analysis (NCA). Mismatch distribution and haplotypes network provided evidences of recent demographic population expansion. Furthermore, the statistical dispersal-vicariance analysis indicated that the center of origin was in Central China. The comparison of haplotype distribution patterns indicated that the regions of HNHPS and HBLD were the potential refugia during the Pleistocene ice ages. Our results highlighted that habitat heterogeneity and physical barriers presenting in a species range can predict genetic patterns. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. Three Dimensional Lithospheric Electrical Structure of the Tibetan Plateau as Revealed by SinoProbe Long Period Magnetotelluric Array Data

    Science.gov (United States)

    Wei, Wenbo; Zhang, Letian; Jin, Sheng; Ye, Gaofeng; Jing, Jianen; Dong, Hao; Xie, Chengliang; Yin, Yaotian

    2017-04-01

    The on-going continent-continent collision between the Indian and Eurasian plates since 55 Ma has created the spectacular topography of the Tibetan plateau. However, many first order questions remain to be answered as to the mechanisms behind this young orogenic process. Under the auspices of the SinoProbe Project, a three dimensional (3-D) Magnetotelluric (MT) array have been deployed on the Tibetan Plateau from 2010 to 2013 to better understand this orogeny. By the end of 2013, 1099 MT stations have been completed, including 102 combined broadband MT (BBMT) and long period MT (LMT) stations. In this study, MT data of these 102 combined stations have been used to investigate the deep lithospheric electrical structure of the Tibetan Plateau. MT impedances within the period range of 10 - 50000 s were extracted to be used for 3-D inversions with the ModEM code using the standard NLCG algorithm. The resulting lithospheric electrical structure of the Tibetan Plateau shows a distinct pattern of strong variation not only vertically, but also horizontally. Conductors are found to be widespread in the middle to lower crust. But their geometries are quite complex, and not obviously consistent with the hypothesis of continuous eastward channel flow. Instead, most crustal conductors in central and southern Tibet display a pattern of N-S extension. In the depth range of the upper mantle, two more conductive regions can be identified in the southern Qiangtang Terrane and in the central Lhasa Terrane. Resistor associated with the underthrust Inidan plate can be traced beneath the Bangong-Nujiang suture in western Tibet, but only beneath the central Lhasa terrane in central Tibet. * This work was jointly supported by the grants from Project SinoProbe-01 and National Natural Science Foundation of China (41404060).

  19. Eutrophication in the Yunnan Plateau lakes: the influence of lake morphology, watershed land use, and socioeconomic factors.

    Science.gov (United States)

    Liu, Wenzhi; Li, Siyue; Bu, Hongmei; Zhang, Quanfa; Liu, Guihua

    2012-03-01

    Lakes play an important role in socioeconomic development and ecological balance in China, but their water quality has deteriorated considerably in recent decades. In this study, we investigated the spatial-temporal variations of eutrophication parameters (secchi depth, total nitrogen, total phosphorus, chemical oxygen demand, chlorophyll-a, trophic level index, and trophic state index) and their relationships with lake morphology, watershed land use, and socioeconomic factors in the Yunnan Plateau lakes. Results indicated that about 77.8% of lakes were eutrophic according to trophic state index. The plateau lakes showed spatial variations in water quality and could be classified into high-nutrient and low-nutrient groups. However, because watersheds were dominated by vegetation, all eutrophication parameters except chlorophyll-a showed no significant differences between the wet and dry seasons. Lake depth, water residence time, volume, and percentage of built-up land were significantly related to several eutrophication parameters. Agricultural land use and social-economic factors had no significant correlation with all eutrophication parameters. Stepwise regression analyses demonstrated that lake depth and water residence time accounted for 73.8% to 87.6% of the spatial variation of single water quality variables, respectively. Redundancy analyses indicated that lake morphology, watershed land use, and socioeconomic factors together explained 74.3% of the spatial variation in overall water quality. The results imply that water quality degradation in the plateau lakes may be mainly due to the domestic and industrial wastewaters. This study will improve our understanding of the determinants of lake water quality and help to design efficient strategies for controlling eutrophication in the plateau region.

  20. Effect of Training on Primary Healthcare Workers in Plateau State ...

    African Journals Online (AJOL)

    Correspondance: Dr Lar, LA (luret _ shown@yahoo.com). Département de médecine communautaire, Jos hôpital d'enseignement de l'Université, Jos, État de Plateau, au. Nigeria P.M. B. 2076. Integrated disease survellance and response reporting. Lar LA. et al. Res. J. of Health Sci. Vol 2(4), Oct./Dec. 2014. 233 ...

  1. Transcranial Doppler Monitoring of Intracranial Pressure Plateau Waves.

    Science.gov (United States)

    Cardim, Danilo; Schmidt, Bernhard; Robba, Chiara; Donnelly, Joseph; Puppo, Corina; Czosnyka, Marek; Smielewski, Peter

    2017-06-01

    Transcranial Doppler (TCD) has been used to estimate ICP noninvasively (nICP); however, its accuracy varies depending on different types of intracranial hypertension. Given the high specificity of TCD to detect cerebrovascular events, this study aimed to compare four TCD-based nICP methods during plateau waves of ICP. A total of 36 plateau waves were identified in 27 patients (traumatic brain injury) with TCD, ICP, and ABP simultaneous recordings. The nICP methods were based on: (1) interaction between flow velocity (FV) and ABP using a "black-box" mathematical model (nICP_BB); (2) diastolic FV (nICP_FV d ); (3) critical closing pressure (nICP_CrCP), and (4) pulsatility index (nICP_PI). Analyses focused on relative changes in time domain between ICP and noninvasive estimators during plateau waves and the magnitude of changes (∆ between baseline and plateau) in real ICP and its estimators. A ROC analysis for an ICP threshold of 35 mmHg was performed. In time domain, nICP_PI, nICP_BB, and nICP_CrCP presented similar correlations: 0.80 ± 0.24, 0.78 ± 0.15, and 0.78 ± 0.30, respectively. nICP_FV d presented a weaker correlation (R = 0.62 ± 0.46). Correlations between ∆ICP and ∆nICP were better represented by nICP_CrCP and BB, R = 0.48, 0.44 (p waves were replicated by nICP methods with strong correlations. In addition, the methods presented high performance for detection of intracranial hypertension. However, absolute accuracy for noninvasive ICP assessment using TCD is still low and requires further improvement.

  2. Individual particles of cryoconite deposited on the mountain glaciers of the Tibetan Plateau: Insights into chemical composition and sources

    Science.gov (United States)

    Dong, Zhiwen; Qin, Dahe; Kang, Shichang; Liu, Yajun; Li, Yang; Huang, Jie; Qin, Xiang

    2016-08-01

    Cryoconite deposited on mountain glacier surfaces is significant for understanding regional atmospheric environments, which could influence the albedo and energy balance of the glacier basins, and maintain the glacial microbiology system. Field observations were conducted on the glaciers of western China, including Laohugou Glacier No.12 (LHG), Tanggula Dongkemadi Glacier (TGL), Zhadang Glacier (ZD), and Baishui Glacier No.1 in the Yulong Mountains (YL), as well as Urumqi Glacier No.1 in the Tianshan Mountains (TS) for comparison with locations in the Tibetan Plateau, in addition to laboratory TEM-EDX analysis of the individual cryoconite particles filtered on lacey carbon (LC) and calcium-coated carbon (Ca-C) TEM grids. This work provided information on the morphology and chemical composition, as well as a unique record of the particle's physical state, of cryoconite deposition on the Tibetan Plateau. The result showed that there is a large difference in the cryoconite particle composition between various locations on the Tibetan Plateau. In total, mineral dust particles were dominant (>50%) in the cryoconite at all locations. However, more anthropogenic particles (e.g., black carbon (BC) and fly ash) were found in YL (38%) and ZD (22%) in the Ca-C grids in the southern locations. In TGL, many NaCl and MCS particles (>10%), as well as few BC and biological particles (Asia to the Tibetan Plateau. Cryoconite in the northern locations (e.g., TGL, LHG, and TS) with higher dust and salt particle ratio are influenced by large deserts in central Asia. Therefore, the transport and deposition of cryoconite is of great significance for understanding regional atmospheric environment and circulation. Large amounts of biological, NaCl and MCS particles were observed in the cryoconite, implying that in addition to dust and BC, many types of light absorbing impurities (LAI) together could influence the glacier albedo change and induce ice melting in the mountain glaciers of the

  3. Using remote sensing data to evaluate the impacts of re-vegetation on soil moisture of the Loess Plateau

    Science.gov (United States)

    Rui, Li

    2017-04-01

    A large-scale re-vegetation supported by the Grain for Green Project (GGP) has greatly changed local eco-hydrological systems of Loess Plateau, in the meantime, with an impact on soil moisture conditions . It is important to know how exactly re-vegetation influences soil moisture condition, which not only crucially constraint growth and distribution of vegetation, and hence, further re-vegetation in the region but also determine the degree of soil desiccation and thus erosion risk. In this study, three eco-environmental factors, which are soil water index (SWI), the Normalized Difference Vegetation Index (NDVI) and precipitation, were used to analyze the response of soil moisture in the 1-metre layer of top soil to the re-vegetation. SWI was estimated based on the back-scatter coefficient produced by the European Remote Sensing Satellite (ERS-1/2) and Meteorological Operational satellite program (MetOp) while NDVI was derived from SPOT imagery. Two separate periods, which are 1998-2000 and 2008-2010, were selected to examine the spatio-temporal pattern of the chosen eco-environmental factors. It has been shown that the amount of precipitation in 1998-2000 was close to that of 2008-2010 (the difference being 13.10 mm). From 1998-2000 to 2008-2010, the average annual NDVI increased for 80.99%, while the SWI decreased for 72.64% of the area on the Loess Plateau. More specifically, 57.65% of the area on the Loess Plateau experienced an increased NDVI and decreased SWI. These results indicate that re-vegetation and climate changes have impacts on soil moisture. However, re-vegetation may be the major factor for soil moisture change in most areas of the Loess Plateau. It is ,therefore, suggested that soil moisture content (SMC) should be kept in mind when carrying out re-vegetation in the arid and semi-arid regions. Keywords: Grain for Green Project (GGP), soil water index (SWI) ,Normalized Difference Vegetation Index (NDVI), Loess Plateau, remote sensing

  4. Bicondylar tibial plateau fracture after posterior cruciate ligament reconstruction.

    Science.gov (United States)

    Griesser, Michael J; McCoy, Brett W; Hussain, Waqas M; Saluan, Paul

    2015-03-01

    The authors present a report of a bicondylar tibial plateau fracture in an adolescent athlete after posterior cruciate ligament (PCL) reconstruction. The procedure was performed via arthroscopic transtibial PCL reconstruction with quadrupled semi-tendinosus and gracilis autograft. The patient recovered uneventfully postoperatively and was able to participate in high-level sports activity, such as baseball and track, with no limitations, no subjective complaints, and no episodes of instability. He continued to be asymptomatic up to 3.5 years postoperatively. Almost 4 years postoperatively, the patient reinjured the left knee during recreational noncontact football and was seen emergently. Plain radiographs, magnetic resonance image scan, and computed tomography scan at the time of injury showed a bicondylar tibial plateau fracture with intra-articular involvement. Operative intervention was undertaken for open reduction and internal fixation of the bicondylar tibial plateau fracture. A plate was placed along the medial aspect of the tibia with locking and nonlocking screws, and the joint line was restored appropriately. The patient recovered uneventfully and at the most recent follow-up had full active and passive range of motion, had no subjective or objective evidence of instability, and had returned to full activity with no restrictions. The patient had no history of multiple fractures or any medical or pharmacologic history that predisposed him to decreased bone density. This case shows a unique possible complication after transtibial PCL reconstruction in an adolescent patient. Copyright 2015, SLACK Incorporated.

  5. Plateau inflation in R-parity violating MSSM

    Directory of Open Access Journals (Sweden)

    Girish Kumar Chakravarty

    2016-12-01

    Full Text Available Inflation with plateau potentials give the best fit to the CMB observables as they predict tensor to scalar ratio stringently bounded by the observations from Planck and BICEP2/Keck. In supergravity models it is possible to obtain plateau potentials for scalar fields in the Einstein frame which can serve as the inflation potential by considering higher dimensional Planck suppressed operators and by the choice of non-canonical Kähler potentials. We construct a plateau inflation model in MSSM where the inflation occurs along a sneutrino-Higgs flat direction. A hidden sector Polonyi field is used for the breaking of supersymmetry after the end of the inflation. The proper choice of superpotential leads to strong stabilization of the Polonyi field, mZ2≫m3/22, which is required to solve the cosmological moduli problem. Also, the SUSY breaking results in a TeV scale gravitino mass and scalar masses and gives rise to bilinear and trilinear couplings of scalars which can be tested at the LHC. The sneutrino inflation field can be observed at the LHC as a TeV scale diphoton resonance like the one reported by CMS and ATLAS.

  6. Mixing on the Heard Island Plateau during HEOBI

    Science.gov (United States)

    Robertson, R.

    2016-12-01

    On the plateau near Heard and McDonald Islands, the water column was nearly always well mixed. Typically, temperature differences between the surface and the bottom, 100-200 m, were less than 0.2oC and often less that 0.1oC. Surface stratification developed through insolation and deep primarily through a combination of upwelling from canyons and over the edge of the plateau and tidal advection. This stratification was primarily removed by a combination of wind and tidal mixing. Persistent winds of 30 knots mixed the upper 20-50 m. Strong wind events, 40-60 knots, mixed the water column to 100-200 m depth, which over the plateau, was often the entire water column. Benthic tidal friction mixed the bottom 30-50 m. Although the water column was unstratified at the two plume sites intensively investigated, tidal velocities were baroclinic, probably due to topographic controls. Tidal advection changed the bottom temperatures by 0.5oC within 8 hours, more than doubling the prior stratification. Wind mixing quickly homogenized the water column, resulting in the surface often showing the deeper upwelling and advective events. Although acoustic plumes with bubbles were observed in the water column, there was no evidence of geothermal vents or geothermal influence on temperatures. Mixing by bubbles rising in the water column was indistinguishable from the wind and tidal mixing, although the strongest upward vertical velocities were observed at the sites of these acoustic/bubble plumes.

  7. Velocity spectrum for the Iranian plateau

    Science.gov (United States)

    Bastami, Morteza; Soghrat, M. R.

    2017-09-01

    Peak ground acceleration (PGA) and spectral acceleration values have been proposed in most building codes/guidelines, unlike spectral velocity (SV) and peak ground velocity (PGV). Recent studies have demonstrated the importance of spectral velocity and peak ground velocity in the design of long period structures (e.g., pipelines, tunnels, tanks, and high-rise buildings) and evaluation of seismic vulnerability in underground structures. The current study was undertaken to develop a velocity spectrum and for estimation of PGV. In order to determine these parameters, 398 three-component accelerograms recorded by the Building and Housing Research Center (BHRC) were used. The moment magnitude (Mw) in the selected database was 4.1 to 7.3, and the events occurred after 1977. In the database, the average shear-wave velocity at 0 to 30 m in depth (Vs30) was available for only 217 records; thus, the site class for the remaining was estimated using empirical methods. Because of the importance of the velocity spectrum at low frequencies, the signal-to-noise ratio of 2 was chosen for determination of the low and high frequency to include a wider range of frequency content. This value can produce conservative results. After estimation of the shape of the velocity design spectrum, the PGV was also estimated for the region under study by finding the correlation between PGV and spectral acceleration at the period of 1 s.

  8. Three decades of elevation change of the Geikie Plateau ice cap, East Greenland

    DEFF Research Database (Denmark)

    Ahlstrom, A. P.; Forsberg, René; Skourup, Henriette

    The Geikie Plateau is a major marine-terminating local ice cap located in central East Greenland just south of Scoresby Sund, covering approx. 7,500 sqkm. South of this region, the Greenland ice sheet has experienced dramatic ice loss over the recent decade, whereas the response has been less...... change. In this work we will compare remotely sensed elevation data collected over more than three decades from the Geikie Ice Cap to evaluate volume change. Elevation data was obtained from aerial stereophotogrammetry based on orthophotos from 1981, spaceborne laser altimetry from ICESat over the period...... 2002-2009, aerial laser altimetry by the NASA IceBridge campaign 2010-2012 and aerial laser altimetry by the Technical University of Denmark and the Danish Geodata Agency covering 1996-2012. The comparison will facilitate an enhanced understanding of recent mass loss from ice caps and glaciers in East...

  9. Elemental composition of Tibetan Plateau top soils and its effect on evaluating atmospheric pollution transport.

    Science.gov (United States)

    Li, Chaoliu; Kang, Shichang; Zhang, Qianggong

    2009-01-01

    The Tibetan Plateau (TP) is an ideal place for monitoring the atmospheric environment of low to mid latitudes. In total 54 soil samples from the western TP were analyzed for major and trace elements. Results indicate that concentrations of some typical "pollution" elements (such as As) are naturally high here, which may cause incorrect evaluation for the source region of these elements, especially when upper continental crust values are used to calculate enrichment factors. Because only particles elemental concentrations of this fraction of the TP soils are more reliable for the future aerosol related studies over the TP. In addition, REE compositions of the TP soils are unusual, highly characteristic and can be used as an effective index for identifying dust aerosol from the TP.

  10. What controls the partitioning between baseflow and mountain block recharge in the Qinghai-Tibet Plateau?

    Science.gov (United States)

    Yao, Yingying; Zheng, Chunmiao; Andrews, Charles; Zheng, Yi; Zhang, Aijing; Liu, Jie

    2017-08-01

    Mountainous areas are referred to as "water towers" since they are the source of water for many low-lying communities. The hydrologic budgets of these areas, which are particularly susceptible to climate change, are typically poorly constrained. To address this, we analyzed the partitioning between baseflow and mountain block recharge (MBR) using a regional groundwater model of the northern Qinghai-Tibet Plateau run with multiple scenarios. We found that 19% of precipitation is recharged, approximately 35% of which becomes MBR, while 65% discharges as baseflow. This partitioning is relatively independent of the recharge rate but is sensitive to exponential depth decrease of hydraulic conductivity (K). The MBR is more sensitive to this exponential decrease in K than baseflow. The proportion of MBR varies from twice to half of baseflow as the decay exponent increases by more than fivefold. Thus, the depth dependence of K is critical for quantifying hydrologic partitioning in these sensitive areas.

  11. Regional tectonic trends on the inner continental shelf off Konkan and central west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Ramana, M.V.

    Satellite imagery and offshore magnetic data were analysed to correlate regional tectonic elements on the inner continental shelf off Konkan and the adjacent Deccan plateau. Three statistically important lineament trends N-S, WNW-ESE and ENE...

  12. Rocky Mountain Regional CO{sub 2} Storage Capacity and Significance

    Energy Technology Data Exchange (ETDEWEB)

    Laes, Denise; Eisinger, Chris; Esser, Richard; Morgan, Craig; Rauzi, Steve; Scholle, Dana; Matthews, Vince; McPherson, Brian

    2013-08-30

    The purpose of this study includes extensive characterization of the most promising geologic CO{sub 2} storage formations on the Colorado Plateau, including estimates of maximum possible storage capacity. The primary targets of characterization and capacity analysis include the Cretaceous Dakota Formation, the Jurassic Entrada Formation and the Permian Weber Formation and their equivalents in the Colorado Plateau region. The total CO{sub 2} capacity estimates for the deep saline formations of the Colorado Plateau region range between 9.8 metric GT and 143 metric GT, depending on assumed storage efficiency, formations included, and other factors.

  13. Patterns of cave biodiversity and endemism in the Appalachians and Interior Plateau of Tennessee, USA.

    Science.gov (United States)

    Niemiller, Matthew L; Zigler, Kirk S

    2013-01-01

    Using species distribution data, we developed a georeferenced database of troglobionts (cave-obligate species) in Tennessee to examine spatial patterns of species richness and endemism, including >2000 records for 200 described species. Forty aquatic troglobionts (stygobionts) and 160 terrestrial troglobionts are known from caves in Tennessee, the latter having the greatest diversity of any state in the United States. Endemism was high, with 25% of terrestrial troglobionts (40 species) and 20% of stygobionts (eight species) known from just a single cave and nearly two-thirds of all troglobionts (130 species) known from five or fewer caves. Species richness and endemism were greatest in the Interior Plateau (IP) and Southwestern Appalachians (SWA) ecoregions, which were twice as diverse as the Ridge and Valley (RV). Troglobiont species assemblages were most similar between the IP and SWA, which shared 59 species, whereas the RV cave fauna was largely distinct. We identified a hotspot of cave biodiversity with a center along the escarpment of the Cumberland Plateau in south-central Tennessee defined by both species richness and endemism that is contiguous with a previously defined hotspot in northeastern Alabama. Nearly half (91 species) of Tennessee's troglobiont diversity occurs in this region where several cave systems contain ten or more troglobionts, including one with 23 species. In addition, we identified distinct troglobiont communities across the state. These communities corresponded to hydrological boundaries and likely reflect past or current connectivity between subterranean habitats within and barriers between hydrological basins. Although diverse, Tennessee's subterranean fauna remains poorly studied and many additional species await discovery and description. We identified several undersampled regions and outlined conservation and management priorities to improve our knowledge and aid in protection of the subterranean biodiversity in Tennessee.

  14. Patterns of cave biodiversity and endemism in the Appalachians and Interior Plateau of Tennessee, USA.

    Directory of Open Access Journals (Sweden)

    Matthew L Niemiller

    Full Text Available Using species distribution data, we developed a georeferenced database of troglobionts (cave-obligate species in Tennessee to examine spatial patterns of species richness and endemism, including >2000 records for 200 described species. Forty aquatic troglobionts (stygobionts and 160 terrestrial troglobionts are known from caves in Tennessee, the latter having the greatest diversity of any state in the United States. Endemism was high, with 25% of terrestrial troglobionts (40 species and 20% of stygobionts (eight species known from just a single cave and nearly two-thirds of all troglobionts (130 species known from five or fewer caves. Species richness and endemism were greatest in the Interior Plateau (IP and Southwestern Appalachians (SWA ecoregions, which were twice as diverse as the Ridge and Valley (RV. Troglobiont species assemblages were most similar between the IP and SWA, which shared 59 species, whereas the RV cave fauna was largely distinct. We identified a hotspot of cave biodiversity with a center along the escarpment of the Cumberland Plateau in south-central Tennessee defined by both species richness and endemism that is contiguous with a previously defined hotspot in northeastern Alabama. Nearly half (91 species of Tennessee's troglobiont diversity occurs in this region where several cave systems contain ten or more troglobionts, including one with 23 species. In addition, we identified distinct troglobiont communities across the state. These communities corresponded to hydrological boundaries and likely reflect past or current connectivity between subterranean habitats within and barriers between hydrological basins. Although diverse, Tennessee's subterranean fauna remains poorly studied and many additional species await discovery and description. We identified several undersampled regions and outlined conservation and management priorities to improve our knowledge and aid in protection of the subterranean biodiversity in

  15. Investigating water budget dynamics in 18 river basins across the Tibetan Plateau through multiple datasets

    Science.gov (United States)

    Liu, Wenbin; Sun, Fubao; Li, Yanzhong; Zhang, Guoqing; Sang, Yan-Fang; Lim, Wee Ho; Liu, Jiahong; Wang, Hong; Bai, Peng

    2018-01-01

    The dynamics of basin-scale water budgets over the Tibetan Plateau (TP) are not well understood nowadays due to the lack of in situ hydro-climatic observations. In this study, we investigate the seasonal cycles and trends of water budget components (e.g. precipitation P, evapotranspiration ET and runoff Q) in 18 TP river basins during the period 1982-2011 through the use of multi-source datasets (e.g. in situ observations, satellite retrievals, reanalysis outputs and land surface model simulations). A water balance-based two-step procedure, which considers the changes in basin-scale water storage on the annual scale, is also adopted to calculate actual ET. The results indicated that precipitation (mainly snowfall from mid-autumn to next spring), which are mainly concentrated during June-October (varied among different monsoons-impacted basins), was the major contributor to the runoff in TP basins. The P, ET and Q were found to marginally increase in most TP basins during the past 30 years except for the upper Yellow River basin and some sub-basins of Yalong River, which were mainly affected by the weakening east Asian monsoon. Moreover, the aridity index (PET/P) and runoff coefficient (Q/P) decreased slightly in most basins, which were in agreement with the warming and moistening climate in the Tibetan Plateau. The results obtained demonstrated the usefulness of integrating multi-source datasets to hydrological applications in the data-sparse regions. More generally, such an approach might offer helpful insights into understanding the water and energy budgets and sustainability of water resource management practices of data-sparse regions in a changing environment.

  16. On the brink of change: plant responses to climate on the Colorado Plateau

    Science.gov (United States)

    Munson, Seth M.; Belnap, Jayne; Schelz, Charles D.; Moran, Mary; Carolin, Tara W.

    2011-01-01

    The intensification of aridity due to anthropogenic climate change in the southwestern U.S. is likely to have a large impact on the growth and survival of plant species that may already be vulnerable to water stress. To make accurate predictions of plant responses to climate change, it is essential to determine the long-term dynamics of plant species associated with past climate conditions. Here we show how the plant species and functional types across a wide range of environmental conditions in Colorado Plateau national parks have changed with climate variability over the last twenty years. During this time, regional mean annual temperature increased by 0.18°C per year from 1989–1995, 0.06°C per year from 1995–2003, declined by 0.14°C from 2003–2008, and there was high interannual variability in precipitation. Non-metric multidimensional scaling of plant species at long-term monitoring sites indicated five distinct plant communities. In many of the communities, canopy cover of perennial plants was sensitive to mean annual temperature occurring in the previous year, whereas canopy cover of annual plants responded to cool season precipitation. In the perennial grasslands, there was an overall decline of C3 perennial grasses, no change of C4 perennial grasses, and an increase of shrubs with increasing temperature. In the shrublands, shrubs generally showed no change or slightly increased with increasing temperature. However, certain shrub species declined where soil and physical characteristics of a site limited water availability. In the higher elevation woodlands, Juniperus osteosperma and shrub canopy cover increased with increasing temperature, while Pinus edulis at the highest elevation sites was unresponsive to interannual temperature variability. These results from well-protected national parks highlight the importance of temperature to plant responses in a water-limited region and suggest that projected increases in aridity are likely to promote

  17. Nonlinear analysis of drainage systems to examine surface deformation: an example from Potwar Plateau (Northern Pakistan

    Directory of Open Access Journals (Sweden)

    F. Shahzad

    2010-03-01

    Full Text Available We devise a procedure in order to characterize the relative vulnerability of the Earth's surface to tectonic deformation using the geometrical characteristics of drainage systems. The present study focuses on the nonlinear analysis of drainage networks extracted from Digital Elevation Models in order to localize areas strongly influenced by tectonics. We test this approach on the Potwar Plateau in northern Pakistan. This area is regularly affected by damaging earthquakes. Conventional studies cannot pinpoint the zones at risk, as the whole region is characterized by a sparse and diffuse seismicity. Our approach is based on the fact that rivers tend to linearize under tectonic forcing. Thus, the low fractal dimensions of the Swan, Indus and Jehlum Rivers are attributed to neotectonic activity. A detailed textural analysis is carried out to investigate the linearization, heterogeneity and connectivity of the drainage patterns. These textural aspects are quantified using the fractal dimension, as well as lacunarity and succolarity analysis. These three methods are complimentary in nature, i.e. objects with similar fractal dimensions can be distinguished further with lacunarity and/or succolarity analysis. We generate maps of fractal dimensions, lacunarity and succolarity values using a sliding window of 2.5 arc minutes by 2.5 arc minutes (2.5'×2.5'. These maps are then interpreted in terms of land surface vulnerability to tectonics. This approach allowed us to localize several zones where the drainage system is highly structurally controlled on the Potwar Plateau. The region located between Muree and Muzaffarabad is found to be prone to destructive events whereas the area westward from the Indus seems relatively unaffected. We conclude that a nonlinear analysis of the drainage system is an efficient additional tool to locate areas likely to be affected by massive destructing events affecting the Earth's surface and therefore threaten human

  18. Conservation Tillage on the Loess Plateau, China: Food security, Yes; Carbon sequestration, No?

    Science.gov (United States)

    Kuhn, Nikolaus; Hu, Yaxian; Xiao, Liangang; Greenwood, Phil; Bloemertz, Lena

    2015-04-01

    Climate change is expected to affect food security globally and increase the variability in food supply. At the same time, agricultural practices offer a great potential for mitigating and adapting to climate change. In China, food security has increased in the last decades with the number of undernourished people declining from 21% in 1990 to 12% today. However, the limited relative amount of arable land and scarce water supplies will remain a challenge. The Loess Plateau of China, located in the mid-upper reaches of the Yellow River and has an area of some 630000 km2 with a high agricultural potential. However, due to heavy summer rainstorms, steep slopes, low vegetation cover, and highly erodible soils, the Loess Plateau has become one of the most severely eroded areas in the world. Up to 70% of arable land is affected by an annual soil loss of 20-25 ton ha-1, far exceeding the threshold for sustainable use (10 ton ha-1). Rainfed farming systems are dominant on the Loess Plateau, and the farmers in this area have been exposed to a steadily increasing temperature as well as an erratic, but slightly decreasing rainfall since 1970. Therefore, adaptation of the regional agriculture is required to adapt to climate change and may be even engaged in mitigation. This study analyzed the potential contribution of conservation tillage to adaptation and mitigation of climate change on the Loess Plateau. In total, 15 papers published in English were reviewed, comparing two tillage practices, conventional tillage (CT) and conservation tillage typically represented by no-tillage (NT). Soil organic carbon (SOC) stock across soil depths as well yields and the inter-annual variations with regards to and their annual rainfall precipitation were compared for NT and CT. Our results show that: 1) The benefit of NT compared to CT in terms of increasing total SOC stocks diminishes with soil depth, questioning the use of average SOC stocks observed in topsoil to estimate the potential

  19. Late Cenozoic tectonic evolution of the Ailao Shan-Red River fault (SE Tibet): implications for kinematic change during Plateau growth

    Science.gov (United States)

    Wang, Yang; Zhang, Bo; Schoenbohm, Lindsay; Zhang, Jinjiang; Zhou, Renjie; Hou, Jianjun

    2016-04-01

    The India-Eurasia continental collision has created the Tibetan Plateau, a spectacular example of continental plateaus. Along its southeastern margin, surface uplift, river incision, shear-zone exhumation and displacement along active faults have all interacted to shape the landscape. The Ailao Shan-Red River fault, a continental-scale strike-slip fault striking over 1000 km from the Tibetan Plateau to South China Sea, is an excellent recorder for those processes, providing important insights into the evolution of the southeastern plateau margin. However, its late Cenozoic tectonic evolution still remains elusive. This work presents new structural and stratigraphic data from the Miocene basin in the bend area and apatite (U-Th)/He thermochronological data from the shear zone to put constraints on the timing and nature of structural and geomorphic evolution of the Ailao Shan-Red River fault region. Our observations indicate that the major bend in the fault was a releasing bend in the early Miocene, but became a restraining bend after the late Miocene reversal of displacement. The strata preserved in bend area record the nature and timing of exhumation of the shear zone. Apatite (U-Th)/He data show two phases of rapid exhumation in the Miocene. The first rapid exhumation occurred before 16 Ma, the timing of which is supported by the early Miocene sedimentary record and previous geochronologic results. It may have ended before the formation of a low-relief erosion surface. The second episode of rapid exhumation began at ~14-13 Ma, lasting 2-3Myr. During this interval, the Ailao Shan range may have uplift to the modern elevation and the high relief may have developed along the range due to river incision. Metamorphic clasts from the shear zone were deposited in the Red River valley. Regional compilation reveals a coincidence of tectonic events in the Tibetan Plateau and its surroundings in the middle-late Miocene, indicating dramatic kinematic change during the course

  20. Investigation of the geology and hydrology of the Coconino Plateau of northern Arizona: a project of the Arizona Rural Watershed Initiative

    Science.gov (United States)

    Flynn, Marilyn E.; Bills, Donald J.

    2002-01-01

    The water resources of the Coconino Plateau in northern Arizona are under increasing demand as a result of development. The population of this arid region continues to grow, and the number of visitors to the many national and state parks and monuments in the region has increased annually. The sustainability, protection, and maintenance of springs and seeps and associated riparian habitat on the Coconino Plateau are major issues that have broad public and governmental support. Regional stakeholders agree that an improved understanding of the regional hydrogeologic system is needed to address the concerns of water supply and ground-water sustainability. The base of information required to adequately describe the hydrogeology of the Coconino Plateau currently does not exist. Hydrogeologic data is most abundant for large population centers like Flagstaff and Sedona, but is sparse for less populated areas like Williams, Tusayan, Valle, and Cameron. There are still large parts of the Coconino Plateau for which there is no basic geologic or hydrologic information available. In order to develop a hydrogeologic framework for the Coconino Plateau, a comprehensive effort is needs to compile existent data and collect additional data to fill in data gaps and reinforce limited information. In 1999, the U.S. Geological Survey (USGS) began an assessment of the hydrogeology of the Coconino Plateau in cooperation with the Arizona Department of Water Resources (ADWR) as part of the Rural Watershed Initiative, a program established by the State of Arizona and managed by the ADWR. Assessments also are underway in the upper-middle Verde River watershed (Woodhouse and others, 2002) to the south and in the Mogollon Highlands to the southeast (Parker and Flynn, 2000). Each study has as its objectives: (1) the collection, compilation, and evaluation of all existing geologic, hydrologic, and related data pertaining to the study area and the creation of a database that is readily accessible

  1. Insights into elevation-dependent warming in the Tibetan Plateau-Himalayas from CMIP5 model simulations

    Science.gov (United States)

    Palazzi, Elisa; Filippi, Luca; von Hardenberg, Jost

    2017-06-01

    We use the output of twenty-seven Global Climate Models participating in the Coupled Model Intercomparison Project phase 5 (CMIP5) to investigate the temperature changes and their dependence on the elevation in the Tibetan Plateau, Himalaya and Karakoram mountains and in the surrounding areas in historical model simulations and in future projections. The aim of this study is to explore if and to what extent the CMIP5 models show elevation-dependent warming (EDW) in this part of the globe and to investigate what are the driving factors at play and their relative importance. Our results indicate that the models show enhanced rates of warming at higher elevations in the Tibetan Plateau-Himalayan region in the twentieth century, and this phenomenon is projected to strengthen by the end of the twenty-first century under a high-emission scenario. We find a nonlinear relationship between the warming rates and the elevation, for both the minimum and the maximum temperature: regions with temperatures below the freezing level of water show more warming than the regions with temperatures above, likely suggesting a key role of mechanisms involving water phase changes, the presence/absence of snow and the snow-albedo feedback. We consider the main variables simulated by the CMIP5 models whose change may be related to temperature changes at higher elevations. We find that changes in surface albedo, atmospheric humidity and downward longwave radiation are relevant factors for EDW in the Tibetan Plateau-Himalayas, with surface albedo being the leading driver.

  2. Plateau iris Íris em platô

    Directory of Open Access Journals (Sweden)

    Alberto Diniz Filho

    2008-10-01

    Full Text Available The term plateau iris was first coined in 1958 to describe the iris configuration of a patient. Two years later the concept of plateau iris was published. In 1977, the plateau iris configuration was classically defined as presurgical changes of an eye with a relative normal central anterior chamber depth, flat iris by conventional biomicroscopy, but displaying an extremely narrow or closed angle on gonioscopic examination. On the other hand, the plateau iris syndrome was defined as an acute glaucoma crisis in one eye with a relative normal central anterior chamber depth and patent iridotomy on direct examination, presenting angle closure confirmed by gonioscopic examination after mydriasis. In 1992, the anatomic aspects of plateau iris were studied using ultrasound biomicroscopy. Finally, plateau iris has been considered an anatomic variant of iris structure in which the iris periphery angulates sharply forward from its insertion point and then again angulates sharply and centrally backward, along with an anterior positioning of the ciliary processes seen on ultrasound biomicroscopy. The clinical treatment of plateau iris syndrome is carried out with topical use of pilocarpine. However, the definitive treatment should be fulfilled by performing an argon laser peripheral iridoplasty.O termo íris em platô foi primeiramente inventado em 1958 para descrever a configuração da íris de um paciente. Dois anos depois o conceito de íris em platô foi publicado. Em 1977, a configuração de íris em platô foi classicamente definida como alterações pré-cirúrgicas de um olho com uma profundidade de câmara anterior relativamente normal, íris plana pela biomicroscopia convencional, mas mostrando um ângulo extremamente estreito ou fechado pela gonioscopia. Por outro lado, a síndrome de íris em platô foi definida como uma crise de glaucoma agudo em um olho com uma profundidade de câmara anterior relativamente normal e uma iridectomia patente ao

  3. Early Human Occupation on the Northeast Tibetan Plateau

    Science.gov (United States)

    Rhode, D.; Madsen, D.; Brantingham, P.; Perrault, C.

    2010-12-01

    The Tibetan Plateau presents great challenges for human occupation: low oxygen, high ultraviolet radiation, harsh seasonal climate, low overall biological productivity. How and when early humans were able to cope physiologically, genetically, and behaviorally with these extremes is important for understanding the history of human adaptive flexibility. Our investigations of prehistoric human settlement on the northeast Tibetan Plateau focus on (a) establishing well-dated evidence for occupation of altitudes >3000 m, (b) the environmental context of high altitude adaptation, and (c) relations of hunting and pastoralism to lower-altitude agrarian systems. We observe two major prehistoric settlement patterns in the Qinghai Lake area. The earliest, ~15,000-7500 yr old, consists of small isolated firehearths with sparse associated stone tools and wild mammal remains (1). Numerous hearths often occur in the same localities, indicating repeated short-duration occupations by small hunting parties. A second pattern, ~9000-4000 yr old, was established during the Holocene climatic optimum. These sites represent prolonged seasonal residential occupation, containing dark anthropogenic midden, hearth and pit constructions, abundant stone tools, occasional ceramics, and abundant diverse faunal remains (including medium-large mammals but lacking domestic sheep/yak)(2). These Plateau-margin base camps allowed greater intensity of use of the high Plateau. Residential occupation was strongly influenced by nearby lower-altitude farming communities; development of the socioeconomic landscape along the Yellow River likely played at least as great a role in Plateau occupation patterns as did Holocene environmental changes. Holocene vegetation changes in the NE Tibetan Plateau have been attributed to climate (3) or anthropogenic modification (4). Our results document changes in shrub/tree presence from ~12,000-4000 BP, similar to pollen records, that likely reflect climate rather than

  4. Active shortening and intermontane basin formation in the central Puna Plateau: Salar de Pocitos, NW Argentina (24° 37S, 67° 03W)

    Science.gov (United States)

    Strecker, M. R.; Bookhagen, B.; Alonso, R.

    2012-12-01

    With average elevations of about 3.7 km, the semi-arid to arid Puna Plateau is a first-order morphotectonic province of the southern central Andes and is an integral part of the world's second largest orogenic plateau. With few exceptions, this region consists of internally drained, partly coalesced sedimentary basins that are mainly bordered by 5- to 6-km high reverse-fault bounded basement ranges or volcanic edifices. The basins contain continental evaporites, volcanic and clastic deposits, typically between 3 and 5 km thick, and record protracted sedimentation since the Eo-Oligocene. While these basins and ranges are related to contraction, extensional tectonics associated with mafic volcanism characterizes the eastern and southern sectors of the Puna Plateau, while the eastern flanks of the plateau and the adjacent foreland are subjected to shortening. The changeover from contraction to extension in the Puna appears to have been diachronous. Along the SE plateau margin the changeover based on previously published age dating took place between 7 and 5 Ma, while areas in the central and northern Puna document shortening until 6 and 9 Ma, respectively. In the latter two areas, however, evidence for extension comparable to the eastern and southeastern plateau is scarce. This is compatible with our new observations from the Salar de Pocitos area in the western interior of the plateau, which has been characterized by protracted shortening from the Tertiary to the present-day. The N-S oriented Salar de Pocitos basin (435 km2) is the vestige of a formerly contiguous sedimentary basin that extended to the Salar de Arizaro in the west. Unlike many other basins in this region, the Pocitos basin is bordered by the limb of an anticline developed in Tertiary sedimentary rocks on the west, while the east side comprises the reverse-faulted range front of Sierra Qda. Honda. To the north the basin is closed by transverse-oriented late Miocene volcanic edifices, and to the south

  5. Co-seismic strain changes of Wenchuan Mw7. 9 earthquake recorded by borehole strainmeters on Tibetan plateau

    Directory of Open Access Journals (Sweden)

    Fu Guangyu

    2011-08-01

    Full Text Available Co-seismic strain changes of the Wenchuan Mw7. 9 earthquake recorded with three four-component borehole strainmeters showed NW-SE and roughly EW extensions, respectively, at two locations in the interior and northern part of Tibetan plateau, and NS shortening at a location south of the epicenter, in agreement with the tectonic stress field of this region. The observed values of as much as 10−7 are, however, larger than theoretical values obtained with half-space and spherical-earth dislocation theories, implying the existence of other effects, such as local crustal structure and initial stress.

  6. Organic carbon isotope and molecular fossil records of vegetation evolution in central Loess Plateau since 450 kyr

    OpenAIRE

    Zhou, Bin; Wali, Guzalnur; Peterse, Francien; Bird, Michael I.

    2016-01-01

    Significant uncertainties remain regarding the temporal evolution of natural vegetation during the Quaternary, and drivers of past vegetation change, on the Chinese Loess Plateau (CLP). This study presents analyses of total organic carbon isotopic composition (TOC) and n-alkane ratios (C31/C27) from the Lingtai loess-palaeosol sequence on the central CLP over the last 450 kyr. The results demonstrate that the vegetation in this region comprised a mix of C3 and C4 plants of herb and woody grow...

  7. Seismic reflection data support episodic and simultaneous growth of the Tibetan Plateau since 25 Myr.

    Science.gov (United States)

    Jiang, Xiao-Dian; Li, Zheng-Xiang

    2014-11-13

    The spectacular topography of the Tibetan Plateau is the result of collision between India and Eurasia over some 50 Myr, but how the plateau grew to its present size remains a topic of debate. Work along its eastern margin suggests a two-stage uplift (thus growth of the plateau) since 30-25 Myr. Here we report high-resolution seismic reflection and drill core results from the southern Tarim Basin that indicate a similar pattern for the northern margin of the plateau. The data suggest that uplift in northern Tibet started at ~23 Myr from near sea level, with the first episode finished by ~10 Myr, followed by a post-5-Myr episode of rapid uplift along the present plateau margin. The growth of the Tibetan Plateau after the Eocene thus appears to have been episodic in nature, and near-synchronous along both eastern and northern margins.

  8. Climate impact and adaptation of husbandry on the Mongolian plateau: A review

    Science.gov (United States)

    Miao, L.; Cui, X.

    2015-12-01

    There has been an evolution in the treatment of regional aspects of climate and land use change: from a patchwork of case examples towards a more systematic coverage of regional issues at continental and sub-continental scales in the latest Intergovernmental panel on climate change, especially in arid and semi-arid areas. The region of Inner Asia has long been characterised by important cultural, economic, and ecological ties that transcend international borders, including a common steppe environment, a long history of mobile pastoralism, as well as comparable experiences of socialist and postsocialist transformation. In this research, we focused on the study of the Mongolian Plateau located in eastern Inner Asia, since climate change has already had large impacts on grassland and local households. We explored how the vegetation and animal husbandry responses to climate change in comparison between Inner Mongolia and Mongolia. Our central question then was: how are people in different parts of Inner Mongolia and the Republic of Mongolia are experiencing and responding to climate change across a common grassland environment as a result of the differing social, economic, political, and ecological conditions within each particular state? We believe that comparative and interdisciplinary investigation offers the best prospect for the evaluation of the differing trajectories currently being followed by each Inner Asian state, and the anticipation of the likely effects on the societies and environment of the region in the future.

  9. Plateau iris in Japanese patients with primary angle closure and primary angle closure glaucoma.

    Science.gov (United States)

    Mizoguchi, Takanori; Ozaki, Mineo; Wakiyama, Harumi; Ogino, Nobuchika

    2015-01-01

    To determine the prevalence of plateau iris in Japanese patients with primary angle closure (PAC) and primary angle closure glaucoma (PACG) and analyze the biometric parameters in patients with plateau iris using ultrasound biomicroscopy (UBM). In this cross-sectional observational study, subjects aged >50 years with PAC and PACG who had previously undergone a patent laser peripheral iridotomy underwent UBM in one eye. UBM images were qualitatively analyzed using standardized criteria. Plateau iris in a quadrant was defined by anteriorly directed ciliary body, absent ciliary sulcus, steep iris root from its point of insertion followed by a downward angulation, flat iris plane, and irido-angle contact. At least two quadrants had to fulfill these UBM criteria for an eye to be classified as having plateau iris. A-scan biometry was used to measure anterior segment parameters. Ninety-one subjects with PAC (58 subjects) or PACG (33 subjects) and 68 normal controls were recruited. The mean (standard deviation) ages of PAC and PACG patients and normal controls were 73.5 (6.2) and 72.6 (7.3), respectively. Based on UBM criteria, plateau iris was found in 16 eyes (17.6%) of 91 eyes. In these 16 eyes, quadrant-wise analysis showed ten eyes (62.5%) had plateau iris in two quadrants; four eyes (25%) had plateau iris in three quadrants; and two eyes (12.5%) had plateau iris in four quadrants. Anterior chamber depth, lens thickness, axial length, lens position, and relative lens position were not statistically significant between the group having plateau iris and that not having plateau iris, respectively. Approximately 20% of Japanese subjects with PAC and PACG with a patent laser peripheral iridotomy were found to have plateau iris on UBM. No morphological difference was noted in the anterior segment of the eye between those with or without plateau iris.

  10. Spiny Neurons of Amygdala, Striatum and Cortex Use Dendritic Plateau Potentials to Detect Network UP States

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    Katerina D Oikonomou

    2014-09-01

    Full Text Available Spiny neurons of amygdala, striatum, and cerebral cortex share four interesting features: [1] they are the most abundant cell type within their respective brain area, [2] covered by thousands of thorny protrusions (dendritic spines, [3] possess high levels of dendritic NMDA conductances, and [4] experience sustained somatic depolarizations in vivo and in vitro (UP states. In all spiny neurons of the forebrain, adequate glutamatergic inputs generate dendritic plateau potentials (dendritic UP states characterized by (i fast rise, (ii plateau phase lasting several hundred milliseconds and (iii abrupt decline at the end of the plateau phase. The dendritic plateau potential propagates towards the cell body decrementally to induce a long-lasting (longer than 100 ms, most often 200 – 800 ms steady depolarization (~20 mV amplitude, which resembles a neuronal UP state. Based on voltage-sensitive dye imaging, the plateau depolarization in the soma is precisely time-locked to the regenerative plateau potential taking place in the dendrite. The somatic plateau rises after the onset of the dendritic voltage transient and collapses with the breakdown of the dendritic plateau depolarization. We hypothesize that neuronal UP states in vivo reflect the occurrence of dendritic plateau potentials (dendritic UP states. We propose that the somatic voltage waveform during a neuronal UP state is determined by dendritic plateau potentials. A mammalian spiny neuron uses dendritic plateau potentials to detect and transform coherent network activity into a ubiquitous neuronal UP state. The biophysical properties of dendritic plateau potentials allow neurons to quickly attune to the ongoing network activity, as well as secure the stable amplitudes of successive UP states.

  11. The dating and interpretation of Chusang indicates permanent human occupation of the interior of the Tibetan Plateau in the early Holocene

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    Meyer, Michael; Aldenderfer, Mark; Wang, Zhijun; Hoffmann, Dirk; Dahl, Jenny; Degering, Detlev; Haas, Randy; Schlütz, Frank; Gliganic, Luke; May, Jan-Hendrik

    2017-04-01

    central plateau. We suggest that migration onto the plateau during the early Holocene was enabled by the wetter regional climate at that time. These findings challenge (i) current models of the occupation of the Tibetan Plateau and (ii) the original dating of Chusang that - based on OSL multi-grain dating - suggests and an age for the imprints of ca. 20 ka. 1. Aldenderfer, M. (2011): Peopling the Tibetan plateau: Insights from archaeology. High Alt. Med. Biol. 12, 141-147. 2. Chen, F. H. et al. (2015): Agriculture facilitated permanent human occupation of the Tibetan Plateau after 3600 B.P. Science 347, 248-250. 3. Meyer, M.C. et al. (2017): Permanent human occupation of the central Tibetan Plateau in the early Holocene. Science 355, 64-67. 4. Lu, D. et al. (2016): Ancestral Origins and Genetic History of Tibetan Highlanders. The American Journal of Human Genetics 99, 580-594. 5. Xiang, K. et al. (2013): Identification of a Tibetan-specific mutation in the hypoxic gene EGLN1 and its contribution to high-altitude adaptation. Molecular biology and evolution 30, 1889-1898.

  12. Summary of the mineralogy of the Colorado Plateau uranium ores

    Science.gov (United States)

    Weeks, Alice D.; Coleman, Robert Griffin; Thompson, Mary E.

    1956-01-01

    In the Colorado Plateau uranium has been produced chiefly from very shallow mines in carnotite ores (oxidized vanadiferous uranium ores) until recent deeper mining penetrated black unoxidized ores in water-saturated rocks and extensive exploration has discovered many deposits of low to nonvanadiferous ores. The uranium ores include a wide range from highly vanadiferous and from as much as one percent to a trace of copper, and contain a small amount of iron and traces of lead, zinc, molybdenum, cobalt, nickel, silver, manganese, and other metals. Recent investigation indicates that the carnotite ores have been derived by progressive oxidation of primary (unoxidized) black ores that contain low-valent uranium and vanadium oxides and silicates. The uranium minerals, uraninite and coffinite, are associated with coalified wood or other carbonaceous material. The vanadium minerals, chiefly montroseite, roscoelite, and other vanadium silicates, occur in the interstices of the sandstone and in siltstone and clay pellets as well as associated with fossil wood. Calcite, dolomite, barite and minor amounts of sulfides, arsenides, and selenides occur in the unoxidized ore. Partially oxidized vanadiferous ore is blue black, purplish brown, or greenish black in contrast to the black or dark gray unoxidized ore. Vanadium combines with uranium to form rauvite. The excess vanadium is present in corvusite, fernandinite, melanovanadite and many other quadrivalent and quinquevalent vanadium minerals as well as in vanadium silicates. Pyrite and part or all of the calcite are replaced by iron oxides and gypsum. In oxidized vanadiferous uranium ores the uranium is fixed in the relatively insoluble minerals carnotite and tyuyamunite, and the excess vanadium commonly combines with one or more of the following: calcium, sodium, potassium, magnesium, aluminum, iron, copper, manganese, or barium, or rarely it forms the hydrated pentoxide. The relatively stable vanadium silicates are little

  13. Land Use Changing SOC pool: A Field Investigation from Six Catchments on the Loess Plateau in China

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    Guo, S.; Wang, R.; Hu, Y.

    2016-12-01

    The Loess Plateau in China has long been known for severe erosion, degraded ecosystem and heavy sediment delivery to the Yellow River. Besides the highly erodible loess soil and the hilly geomorphology nature, intensive cultivation has been accused as one of the most destructive anthropogenic activities undermining erosion situation on the Loess Plateau. This made the Loess Plateau once the least fertile region in China with extreme poverty. To preserve soil fertility and ecosystem sustainability, a magnificent national-level project was launched in 1990s to encourage land use changes via afforestation or conversion cropland back to grassland or woodland. After nearly three decades, SOC pool must have been substantially changed following land use conversions. However, climate conditions, geomorphic types and soil properties were spatially distinctive across the Loess Plateau. Their individual as well interactive impacts on changes of soil carbon pool during land use conversions must be properly accounted for. In this study, six watersheds well distributed on the Loess Plateau were investigated. The six watersheds mainly represented three geomorphic types (wide gully, loess ridge, and round knoll), each with three land use types (cropland, grassland and woodland). In total, 695 soil samples were taken from the top 20 cm of the six watersheds during 2010 and 2011. Our results show: 1) Degrees of erosion hugely differed among the six watersheds, with Huangfuchuan having three times more erosion modulus than the least eroded Gaoquangou (21000 vs. 6120 t km-2 per year). 2) The increasing SOC content from 4 mg g-1 at Huangfuchuan to 8.1 mg g-1 at Gaoquangou agreed well with their decreasing erosion modulus, suggesting that geomorphology induced erosion history was the predominant factor to set the general level of watershed-scale SOC reservoir. 3) Within each watershed, grassland and woodland consistently had at least 34% more SOC than cropland, demonstrating the

  14. Spatial variations of seismic attenuation in the North West of Iranian plateau from analysis of coda waves

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    Naghavi, M.; Rahimi, H.; Moradi, A.; Mukhopadhyay, S.

    2017-06-01

    In this study, spatial variation of coda wave attenuation in the north western (NW) Iranian Plateau is explored using local earthquakes. Single backscattering method is used to map the spatial variations of coda Q (Qc) using 14,969 earthquakes which are recorded digitally by sixteen permanent stations. Observed spatial attenuation maps are well correlated with geological setting of study area. North West of Iranian plateau is dominated with high attenuation which is well correlated with Quaternary deposits as well as the Sahnad, Sabalan volcanic zone and Tabriz fault. These observation is in accordance with numerous 2D velocity tomograms which have shown very low velocity in the NW Iran. The region characterized by volcanic structures exhibits mainly higher seismic attenuation than the surrounding regions whereas, Paleo Tethys basin in the eastern part of covered area are categorized by smaller attenuation than the other zone. Our observation shows good correlation with reported lower crustal low-velocity region beneath the Sahand and Sabalan volcanos. The Sahand and Sabalan volcanoes are very large structures and they dominate the Pliocene-Quaternary magmatic landscape of NW Iran. In addition, our observation has clearly shown existence of a probable fault zone trending in NE - SW direction between Tabriz city and Urmia Lake which is consistent with the trend of meizoseismal zone of the Deh-Khareqan (modern Azarshahr) earthquake (M 6.8) in 1641.

  15. Human-Induced Landcover Changes Drive a Diminution of Land Surface Albedo in the Loess Plateau (China

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    Jun Zhai

    2015-03-01

    Full Text Available A large decrease in the land surface albedo of the Loess Plateau was observed from 2000 to 2010, as measured using satellite imagery. In particular, ecological restoration program regions experienced a decrease in peak season land surface albedo exceeding 0.05. In this study, we examined the spatial and temporal patterns of variation during the peak season albedo in the Loess Plateau and analyzed its relationships with changes of anthropogenic and natural factors at the pixel level. Our analysis revealed that increasing grassland coverage due to returning rangeland to grassland could lead to a maximum albedo decrease of 0.030 in peak season. This result highlighted the human-induced land use change in driving the decreasing albedo on an annual scale. There was no significant correlation between precipitation change and albedo reduction. Precipitation could influence the spatial pattern of albedo in drought years by influencing the natural vegetation water requirement. However, the role of precipitation was not obvious in the ecological restoration program regions. This article demonstrates the substantial role that land use change could play in regional-scale albedo change and climate. Finally, some implications for the radiative forcing of land use change are discussed.

  16. Hydrologic feasibility of artificial forestation in the semi-arid Loess Plateau of China

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    T. T. Jin

    2011-08-01

    Full Text Available Hydrologic viability, in terms of moisture availability, is fundamental to ecosystem sustainability in arid and semi-arid regions. In this study, we examine the spatial distribution and after-planting variations of soil moisture content (SMC in black locust tree (Robinia pseudoacacia L. plantings in the Loess Plateau of China at a regional scale. Thirty sites (5 to 45 yr old were selected, spanning an area of 300 km by 190 km in the northern region of the Shaanxi Province. The SMC was measured to a depth of 100 cm at intervals of 10 cm. Geographical, topographic and vegetation information was recorded, and soil organic matter was evaluated. The results show that, at the regional scale, SMC spatial variability was most highly correlated with rainfall. The negative relationship between the SMC at a depth of 20–50 cm and the stand age was stronger than at other depths, although this relationship was not significant at a 5 % level. Watershed analysis shows that the after-planting SMC variation differed depending upon precipitation. The SMC of plantings in areas receiving sufficient precipitation (e.g., mean annual precipitation (MAP of 617 mm may increase with stand age due to improvements in soil water-holding capacity and water-retention abilities after planting. For areas experiencing water shortages (e.g., MAP = 509 mm, evapotranspiration may cause planting soils to dry within the first 20 yr of growth. It is expected that, as arid and semi-arid plantings age, evapotranspiration will decrease, and the soil profile may gradually recover. In extremely dry areas (e.g., MAP = 352 mm, the variation in after-planting SMC with stand age was found to be negligible. The MAP can be used as an index to divide the study area into different ecological regions. Afforestation may sequentially exert positive, negative and negligible effects on SMCs with a decrease in the MAP. Therefore, future restoration measures should correspond to the local climate

  17. Enhancing the early differential diagnosis of plateau iris and pupillary block using a-scan ultrasonography.

    Science.gov (United States)

    Chen, Yu-Yen; Chu, Dachen; Chou, Pesus

    2015-01-01

    To distinguish the frequently misdiagnosed plateau iris eyes from pupillary block group and normal group, we compared the ocular biometrical parameters of them by A-scan ultrasongraphy. In total, we retrospectively reviewed general characteristics and ocular findings including ocular biometric measurements of 71 normal, 39 plateau iris, and 83 pupillary block eyes. The normal controls, plateau iris group and pupillary block group were significantly different in age, but not in gender. The anterior chamber depth tended to decrease and the lens thickness tended to increase from normal to plateau iris to pupillary block eyes. Compared to those of plateau iris group, the pupillary block group had significantly shallower anterior chamber depth (2.90mm vs. 2.33mm; piris and normal eyes, only axial length and lens/axial length factor were significantly different (23.16 vs. 23.54; pbiometrics of plateau iris were significantly different from those of pupillary block eyes. However, our A-scan ultrasongraphy generally found no significant biometric differences between plateau iris and normal eyes. These findings suggest that while A-scan ultrasonography might be used as a practical tool for differentiating plateau iris and papillary block eyes, a more meticulous gonioscopy and other assessments may be necessary to distinguish plateau iris from normal eyes.

  18. Medial tibial plateau morphology and stress fracture location: A magnetic resonance imaging study.

    Science.gov (United States)

    Yukata, Kiminori; Yamanaka, Issei; Ueda, Yuzuru; Nakai, Sho; Ogasa, Hiroyoshi; Oishi, Yosuke; Hamawaki, Jun-Ichi

    2017-06-18

    To determine the location of medial tibial plateau stress fractures and its relationship with tibial plateau morphology using magnetic resonance imaging (MRI). A retrospective review of patients with a diagnosis of stress fracture of the medial tibial plateau was performed for a 5-year period. Fourteen patients [three female and 11 male, with an average age of 36.4 years (range, 15-50 years)], who underwent knee MRI, were included. The appearance of the tibial plateau stress fracture and the geometry of the tibial plateau were reviewed and measured on MRI. Thirteen of 14 stress fractures were linear, and one of them stellated on MRI images. The location of fractures was classified into three types. Three fractures were located anteromedially (AM type), six posteromedially (PM type), and five posteriorly (P type) at the medial tibial plateau. In addition, tibial posterior slope at the medial tibial plateau tended to be larger when the fracture was located more posteriorly on MRI. We found that MRI showed three different localizations of medial tibial plateau stress fractures, which were associated with tibial posterior slope at the medial tibial plateau.

  19. Magma storage and evolution of the Central Plateau Member Rhyolites, Yellowstone caldera, USA

    Science.gov (United States)

    Befus, K. S.

    2015-12-01

    We use volatile and trace element contents from quartz-hosted melt inclusions to place constraints on the pre-eruptive storage and evolution of 6 lavas and 3 tuffs from the Central Plateau Member Rhyolites, Yellowstone. Overall, inclusions contain 1.0-2.5% H2O and 50-600 ppm CO2. Individual units have more restricted volatile contents, and define regions in H2O and CO2 space with internal variability of ±0.5 wt.% and ±100 ppm, respectively. Water contents in both lavas and pyroclastic units are similar, but CO2 contents vary and can be used to separate the units as CO2-rich and CO2-poor. CO2-rich units contain 300 to 600 ppm CO2 (Tuff of Bluff Point, Pitchstone Plateau, Trischmann Knob, Buffalo Lake, Summit Lake). CO2-poor units contain 50 to 200 ppm CO2 (Solfatara Plateau, West Yellowstone, Tuff of Cold Mountain Creek, unnamed tuff on Douglas Knob). Volatile contents do not correlate with eruption age, volume, or style. Inclusions from individual units contain incompatible trace-element concentrations that range from primitive to evolved. Incompatible elements within each unit increase systematically from primitive inclusions (units differ by <20%), to more evolved inclusions, and finally to highly evolved matrix. The inclusions preserve a systematic evolution produced by crystal fractionation, which we estimate to range from 38±8 wt.% to 54±11 wt.%. Inclusions from the Tuffs of Bluff Point and Cold Mountain Creek display similar evolution, except that matrix glass in those tuffs is less evolved than the inclusions. We infer the magmas were volatile-saturated at depth because H2O and CO2 do not correlate positively with incompatible elements. If true, then the CO2-rich magmas were stored at 90 to 150 MPa and contained a fluid that was 60-75 mol.% CO2, whereas CO2-poor magmas were stored at 50 to 70 MPa and contained a more H2O-rich fluid (XCO2 = 40-60%). The variations in pressure/depth suggest the magmas were at least temporarily stored as separate batches