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Influence of tributaries on downstream bed sediment grain sizes under flysch conditions

Journal of Mountain Science 2021年第4期18卷 847-862页

作者： SMAZAK Ivan GALLA Tomas department of physical geography and geoecology Faculty of ScienceUniversity of OstravaChittussiho 1071000 OstravaCzech Republic

Tributaries are one of the most important factors contributing to variability in the downstream evolution of bed sediment grain *** primary aim of this work is to evaluate the response of the bed sediment texture in the recipient channel induced by ten tributaries of the?ernáOstravice stream and find reach-scale and catchment-scale parameters that would be able to predict this *** research was based on collecting information on the grain size distributions at sites adjacent to confluence zones.A significant change in sediment texture occurred in the vicinity of five *** the other factors contributing to grain size variability(e.g.,local channel geometry,lithology,and lateral sediment sources),it was assumed that only four of them were associated with a sufficient bedload influx to alter the sediment calibre below the ***,a significant morphological effect in the form of a large confluence bar was observed in one *** tributaries had several common features:(i)they had a larger relative catchment area than that of nonsignificant tributaries;(ii)they were characterized by different bed grain sizes,with some exceptions;and(iii)they had a higher unit stream power close to the confluence in relation to that of the *** characteristics were represented by the proposed relative parameters,including the relative unit stream power and bed material texture,which allowed the best classification of significant and nonsignificant *** their simplified form,the parameters described the transport capacity and grain size distribution,which were generally considered to be primary factors responsible for a redefinition of the sediment texture in the recipient ***,it should be noted that these results are subject to some degree of uncertainty due to the relatively small sample size of only 10 tributaries.

关键词： Tributary Bed sediments Headwater streams Flysch Carpathians

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Assessment of sediment connectivity using modelling and field-based approaches in the Slavíč River catchment(MoravskoslezskéBeskydy Mts,Czech Republic)

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Journal of Mountain Science 2024年第3期21卷 734-753页

作者： MACUROVÁ Tereza ŠKARPICH Václav department of physical geography and geoecology Faculty of ScienceUniversity of OstravaChittussiho 1071000 OstravaCzech Republic

Mountain streams act as conveyors of sediments within the river continuum,where the physical transport of sediments between river reaches through the catchment or between individual parts(e.g.,between hillslopes and channels)of the catchment is *** study focused on sediment connectivity analysis in the SlavíčRiver catchment in the MoravskoslezskéBeskydy Mts in the eastern part of the Czech *** connectivity index and connectivity index target modelling were combined with an analysis of anthropogenic ***,field mapping,grain size of bed sediments and stream power analysis were used to obtain information about connectivity in the *** on the analysis and obtained results,terrain topography is the current main driving factor affecting the connectivity of sediment movement in the SlavíčRiver ***,the modelling provided valuable information about high sediment connectivity despite different recent land use conditions(highly forested area of the catchment)than those in historical times from the 16th to 19th centuries when the SlavíčRiver catchment was highly deforested and sediment connectivity was probably *** analysis of anthropogenic interventions,field mapping,grain size of bed sediments and stream power analysis revealed more deceleration of sediment movement through the catchment,decreased sediment connectivity with bed erosion,and gradual river channel process transformation in some *** mapping has identified various natural formations and human-induced changes impacting the longitudinal and lateral connectivity in the Slavíč*** instance,embankments along 48%of the river's length,both on the right and left banks,significantly hinder lateral sediment supply to the *** power index analysis indicates increased energy levels in the flowing water in the river's upper reaches(up to 404.8 W m^(-2)).This high energy is also observed in certain downstream sections(up to 337.6 W

关键词： Mountain stream Connectivity analysis Modelling Grain size analysis SlavíčRiver MoravskoslezskéBeskydy Mts

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Geomorphic evidence of ancient catastrophic flow type landslides in the mid-mountain ridges of the Western Flysch Carpathian Mountains(Czech Republic)

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International Journal of Sediment Research 2009年第1期24卷 88-98页

作者： T. PNEK J. HRADECKY K. ILHN Assoc. University of Ostrava Faculty of Science Department of Physical Geography and Geoecology Chittussiho 10 71000 Ostrava Czech Republic University of Ostrava Faculty of Science Department of Physical Geography and Geoecology Chittussiho 10 71000 Ostrava Czech Republic

Ancient flow type landslides are relatively frequent fossil forms of the relief in mid-mountain conditions of the Czech Carpathian Mountains. Sixty rather distinctive displays of debris flows,rock avalanches,and debris avalanches have been mapped in the uppermost part of the territory. Unlike contemporary sporadic and low volume debris flows,ancient(Pleistocene and Lower Holocene) accumulations are a few orders of magnitude more extensive and were of considerable geomorphologic significance in forming the steep sections of mountain valleys and slopes. This geomorphic pattern does not hold for flow type slides,the source of which is material released as a consequence of numerous deep-seated landslides. Due to deep disruption of slopes,a few high-magnitude flow type landslides(e.g.,rock avalanches),quite rare in flysch mid-mountain conditions,also occurred in the Late Holocene.

关键词： Debris flows Rock avalanches Deep-seated landslides Flysch Western Carpathian Mountains

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Examining El Nio in the Holocene: implications and challenges

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National Science Review 2018年第6期5卷 807-809页

作者： Zhengyao Lu Zhengyu Liu department of physical geography and Ecosystem Science Lund University department of geography Ohio State University

The El Nio–Southern Oscillation(ENSO) is characterized by year-to-year anomalous surface climate variability over the tropical Pacific. Through atmospheric teleconnections, ENSO can bring droughts and floods worldw... 详细信息

关键词： Examining El Ni implications and challenges o in the Holocene El

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Contribution of biophysical and climate variables to the spatial distribution of wildfires in Iran

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Journal of Forestry Research 2023年第6期34卷 1763-1775页

作者： Kobra Shojaeizadeh Mahmoud Ahmadi Abbasali Dadashi-Roudbari department of physical geography Faculty of Earth SciencesShahid Beheshti UniversityTehranIran department of geography Ferdowsi University of MashhadMashhadIran

This study investigated the relationship between climate and biophysical variables in burned areas in *** fire burned area(FBA)product(Fire CCI 5.1.1),land surface temperature(MOD11C3C),vegetation index(MOD13A1),and climate variables such as temperature,wind speed,relative humidity,and volumetric soil moisture from the ERA5 reanalysis dataset were *** correlation coefficient was used to determine the relationship between biophysical and climate variables and fire *** results show that FBA increased by 1.7 hectares/decade from 2001 to *** high FBA in 2010(the black summer of Iran)was due to high temperatures and significant heatwaves that led to extensive *** anthropogenic activities are considered a significant cause of wildfires,several variables,including increased temperatures,less precipitation,relative humidity,and wind speed and direction,contribute to the extent and occurrence of *** country’s FBA hotspot is in the Arasbaran region during the summer *** and relative humidity are the most significant variables influencing the occurrence of *** results show the vulnerability of Iran s forests and their high potential for *** the frequency of fire occurrences in Iran and the limited equipment,fire prevention plans should be carried out by applying proper management in high-risk regions.

关键词： Wildfire Burned areas Vegetation index(Ⅵ) Air temperature Iran

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The Impact of Topography on Social Factors,a Case Study of Montenegro

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Journal of Mountain Science 2014年第1期11卷 131-141页

作者： TELBISZ Tamás BOTTLIK Zsolt MARI László KOSZEGI Margit department of physical geography Eotvos University department of Regional Science Eotvos University

Relationships between environmental and social factors have long been studied by ***,GIS-aided statistical analysis provides new tools to explore these *** order to detect the impact of topography on social factors,we selected the country of Montenegro as a case example due to its high topographic *** compared the spatial pattern of population,settlements and ethnic minorities to physical geographic factors,especially to topography,but lithology and land cover data were also taken into *** found that certain factors are closely correlated,*** settlement density linearly decreases with elevation,while the characteristic settlement area shows an exponential increase *** population density is not related to absolute elevation,but it is in close correlation with height(*** relative to the local minimum).Population change and illiteracy are also topography-related social *** the contrary,the variable ethnic pattern of Montenegro is influenced by historical,political and economic effects rather than by environmental factors or topographic *** a conclusion we state that in the scale of a country or a region,the environment can strongly impact some social factors.

关键词： Human-environment relations Dinarides GIS Settlements Population Ethnic groups

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Evidence of the formation of landslide-dammed lakes in the Zagros Mountains range,Iran

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Journal of Mountain Science 2019年第10期16卷 2389-2403页

作者： Siyamack SHARAFI Mojtaba YAMANI Mohsen EHTESHAMI-MOINABADI department of physical geography Lorestan UniversityKhorram Abad***Iran department of physical geography University of TehranTehran***Iran department of Sedimentary Basins and Petroleum Shahid Beheshti UniversityTehran***Iran

Alternation of high and low resistance sedimentary beds,active tectonics,large rivers,and slope erosion in valleys consequently resulted in landslide in dammed lakes within the Zagros *** study presents the results in the analysis of geological and topographic data,satellite imageries,morphotectonics and hydrodynamics of drainage networks about the landslide dammed *** are four landslides in central Zagros(Zagros FoldThrust Belt,ZFTB)which have formed five dammed lakes named,Seymareh,Jaidar,Shur,Shimbar,and *** to the results,damming landslides occurred in the active-tectonic regions on the slopes of anticlines and in valleys with undercutting effects of rivers on their slopes consisting of alternations of loose and resistant *** studied landslide dams in narrow valleys are formed as a result of blocking river by sliding debris slopes and rock *** study also indicates the formation of Jaidar and Godar in one stage and the presence of Lake Terrace sequence in Seymareh,Shur and Shimbar *** observed sequences of terrace formation in these lakes are caused by four Seymareh Landslides followed by the three-stage excavation of Shur andShimbar lakes.

关键词： Landslide dams Lake terrace Central Zagros Iran

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The global climate monitor system:from climate data-handling to knowledge dissemination

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International Journal of Digital Earth 2019年第4期12卷 394-414页

作者： Juan Mariano Camarillo-Naranjo José Ignacio Álvarez-Francoso Natalia Limones-Rodríguez María Fernanda Pita-López Mónica Aguilar-Alba department of physical geography and Regional Analysis University of SevilleSevilleSpain department of Human geography University of SevilleSevilleSpain

This paper summarizes our work on building a data model and a geovisualization tool that provides access to global climate data:the Global Climate Monitor Web *** to this viewer,a complete set of climate-environmental indicators capable of displaying climate patterns on a global scale that is accessible to any potential user(scientists and laypeople)will be built and published using the same online *** data currently available correspond to the CRU TS3.21 version of the Climate Research Unit(University of East Anglia)database–a product that provides data at a spatial resolution of half of a degree in latitude and longitude,spanning January 1901 to December 2012,on a monthly *** January 2013,the datasets feeding the system have been the GHCN-CAMS temperature dataset and the Global Precipitation Climatology Centre(GPCC)First Guess precipitation ***,hydrologists,planners and non-experts users such as media workers,policymakers,non-profit organizations,teachers or students,can access useful climatological information through the Global Climate Monitor system.

关键词： Geovisualization climate indicators global climate databases open-source software

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Towards knowledge-based geovisualisation using Semantic Web technologies:a knowledge representation approach coupling ontologies and rules

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International Journal of Digital Earth 2020年第9期13卷 976-997页

作者： Weiming Huang Lars Harrie department of physical geography and Ecosystem Science Lund UniversityLundSweden

Geovisualisation is a knowledge-intensive art in which both providers and users need to possess a wide range of *** syntactic approaches to presenting visualisation information lack semantics on the one hand,and on the other hand are too *** limitations impede the transfer,interpretation,and reuse of the geovisualisation *** this paper,we propose a knowledge-based approach to formally represent geovisualisation knowledge in a semantically-enriched and machine-readable manner using Semantic Web ***,we represent knowledge regarding cartographic scale,data portrayal and geometry source,which are three key aspects of geovisualisation in the contemporary web mapping era,coupling ontologies and semantic *** knowledge base enables inference for deriving the corresponding geometries and portrayals for visualisation under different conditions.A prototype system is developed in which geospatial linked data are used as underlying data,and some geovisualisation knowledge is formalised into a knowledge base to visualise the data and provide rich semantics to *** proposed approach can partially form the foundation for the vision of web of knowledge for geovisualisation.

关键词： Geovisuaisation Semantic Web knowledge representation ontologies semantic rules

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Decreasing nutrient concentrations in soils and trees with increasing elevation across a treelineecotone in Rolwaling Himal, Nepal

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Journal of Mountain Science 2017年第5期14卷 843-858页

作者： Simon DROLLINGER Michael MULLER Timo KOBL Niels SCHWAB Jurgen BOHNER Udo SCHICKHOFF Thomas SCHOLTEN geoecology Department of Geography and Regional Research University of Vienna Vienna Austria Soil Science and Geomorphology Department of Geosciences Uniuersity of Tubingen Tubingen Germany CEN Center for Earth System Research and Sustainability Institute of Geography University of Hamburg Hamburg Germany

At a global scale, tree growth in alpine treeline ecotones is limited by low temperatures. At a local scale, however, tree growth at its upper limit depends on multiple interactions of influencing factors and mechanisms. The aim of our research was to understand local scale effects of soil properties and nutrient cycling on tree growth limitation, and their interactions with other abiotic and biotic factors in a near-natural Himalayan treeline ecotone. Soil samples of different soil horizons, litter, decomposition layers, and foliage samples of standing biomass were collected in four altitudinal zones along three slopes, and were analysed for exchangeable cations and nutrient concentrations, respectively. Additionally, soil and air temperature, soil moisture, precipitation, and tree physiognomy patterns were evaluated. Both soil nutrients and foliar macronutrient concentrations of nitrogen(N), magnesium(Mg), potassium(K), and foliar phosphorus(P) decrease significantly with elevation. Foliar manganese(Mn) concentrations, bycontrast, are extraordinarily high at high elevation sites. Potential constraining factors on tree growth were identified using multivariate statistical approaches. We propose that tree growth, treeline position and vegetation composition are affected by nutrient limitation, which in turn, is governed by low soil temperatures and influenced by soil moisture conditions.

关键词： Foliar nutrients Himalaya Nitrogen Nutrient cycling Podzol Treeline

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