Inference of herder presence from GPS collar data of semi-free range cattle     

Fadzai M. Zengeya  Amon Murwira  Michel de Garine-Witchatitsky 《国际地球制图》2015,30(8):905-918

Although global positioning system (GPS) location data have been used to derive animal movement parameters including step length, rarely have these parameters been used to predict animal responses to human interventions. In this study, we tested whether GPS-derived step length of semi-free range cattle is a function of herder presence. The derived step-length model was used to predict herder presence on independent cattle GPS collar data. We also tested whether cattle foraging behaviour is explained by herder activity and vegetation greenness. We used logistic regression to model herder presence as a function of step length and relate cattle behaviour with herder activity and vegetation greenness. The field-based step length model successfully predicted herder presence on GPS collar data. The average predicted frequency of herder presence for the GPS-collared herds was 31%, whilst the field-based GPS frequency was 27%. Herding activities and vegetation greenness also explained different cattle foraging behaviour.  相似文献   

Contributions of hydrogeophysics to the hydrogeological conceptual model of the Albufeira-Ribeira de Quarteira coastal aquifer in Algarve,Portugal   总被引：1，自引：0，他引：1  

Alain P. Francés  Elsa C. Ramalho  Judite Fernandes  Michel Groen  Rui Hugman  Mohamed A. Khalil  Joel De Plaen  Fernando A. Monteiro Santos 《Hydrogeology Journal》2015,23(7):1553-1572

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华南板块早中生代陆内造山过程——以雪峰山-九岭为例   总被引：3，自引：1，他引：2  

褚杨  林伟  FAURE Michel  王清晨 《岩石学报》2015,31(8):2145-2155

雪峰山-九岭造山带位于华南板块的中心区域,是一条典型的陆内造山带。通过详细的野外地质观察,雪峰山在早中生代经历了3期构造变形:D1为上部指向NW的韧性剪切,D2代表了一期反向褶皱-逆冲构造事件,以及D3期的水平挤压形成的直立的褶皱、劈理和线理。而在九岭,早中生代大规模脆-韧性域构造变形叠加在早古生代韧性变形之上,形成了一系列极性NW逆冲断层和不对称褶皱。雪峰山-九岭陆内造山带形成于早中生代,造山作用可以分为两个阶段,即245~225Ma的挤压变形阶段和225~215Ma的垮塌-岩浆侵位阶段。雪峰山-九岭造山带的构造特点表明,华南板块东南缘古太平洋板块向北西方向的俯冲可能引发了早中生代的陆内造山过程。  相似文献   

Climatic oscillations in central Italy during the Last Glacial–Holocene transition: the record from Lake Accesa     

Michel Magny  Jacques‐Louis de Beaulieu  Ruth Drescher‐Schneider  Boris Vannire  Anne‐Vronique Walter‐Simonnet  Laurent Millet  Gilles Bossuet  Odile Peyron 《第四纪科学杂志》2006,21(4):311-320

This paper presents an event stratigraphy based on data documenting the history of vegetation cover, lake‐level changes and fire frequency, as well as volcanic eruptions, over the Last Glacial–early Holocene transition from a terrestrial sediment sequence recovered at Lake Accesa in Tuscany (north‐central Italy). On the basis of an age–depth model inferred from 13 radiocarbon dates and six tephra horizons, the Oldest Dryas–Bølling warming event was dated to ca. 14 560 cal. yr BP and the Younger Dryas event to ca. 12 700–11 650 cal. yr BP. Four sub‐millennial scale cooling phases were recognised from pollen data at ca. 14 300–14 200, 13 900–13 700, 13 400–13 100 and 11 350–11 150 cal. yr BP. The last three may be Mediterranean equivalents to the Older Dryas (GI‐1d), Intra‐Allerød (GI‐1b) and Preboreal Oscillation (PBO) cooling events defined from the GRIP ice‐core and indicate strong climatic linkages between the North Atlantic and Mediterranean areas during the last Termination. The first may correspond to Intra‐Bølling cold oscillations registered by various palaeoclimatic records in the North Atlantic region. The lake‐level record shows that the sub‐millennial scale climatic oscillations which punctuated the last deglaciation were associated in central Italy with different successive patterns of hydrological changes from the Bølling warming to the 8.2 ka cold reversal. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Expanding the observational foundation for climate studies     

Michel Petit 《Comptes Rendus Geoscience》2005,337(12):1023-1025

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The onset of natural convection in vertical fault planes:consequences for the thermal regime in crystalline basementsand for heat recovery experiments     

Cécile Tournier  Pierre Genthon  & Michel Rabinowicz 《Geophysical Journal International》2000,140(3):500-508

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Mountain building and exhumation processes through time: inferences from nature and models     

Denis Gapais  Florence Cagnard  Frédéric Gueydan  Pierre Barbey  Michel Ballèvre 《地学学报》2009,21(3):188-194

Orogenic belts involving initially hot lithospheres, as exemplified by accretionary-type orogens, commonly show distributed deformation and retrograde PT paths with a concomitant decrease in pressure and temperature. Paths may track geotherms, indicating thermal equilibrium, consistent with slow strain and exhumation rates, limited strain localization, and consequently limited topographical gradients and distributed erosion. Such patterns are more common in Precambrian times than in younger periods of the Earth history. In contrast, orogens involving initially stiff lithospheres show exhumation PT paths that track isothermal decompression reflecting high strain rates along major shear zones, a feature typical of Phanerozoic collision belts. Field evidence, analogue and numerical models emphasize that strain localization has first-order consequences for the tectonic evolution of orogenic zones including structure, metamorphism, exhumation processes, topography, erosion and sedimentation modes.  相似文献   

Formation of the Upper Pleistocene terraces of Lake Van (Turkey)     

Catherine Kuzucuoğlu  Aurélien Christol  Damase Mouralis  Ali‐Fuat Doğu  Ebru Akköprü  Monique Fort  Daniel Brunstein  Halil Zorer  Michel Fontugne  Mustafa Karabiyikoğlu  Stéphane Scaillet  Jean‐Louis Reyss  Hervé Guillou 《第四纪科学杂志》2010,25(7):1124-1137

Sedimentological and geomorphological studies of terraces around Lake Van (1647 m) provided a preliminary framework for lake‐level variations. The elevations of terraces and past lake level were measured with a differential global positioning system. A chronology is developed using ²³⁴U/²³⁰Th dating of travertines, ³⁹Ar/⁴⁰Ar dating of pyroclastites and ¹⁴C dating of organic matter. Facies and stratigraphic correlations identify four transgressions (C1′, C1″, C2′ and C2″), each followed by a regression which ended with low lake levels that caused river incision and terrace formation. Evidence of the oldest transgression (C1′) is found in the uppermost reaches of valleys up to 1755 m, an altitude higher than the present lake threshold (1736 m). This C1′ transgression may be related to pyroclastic flows which dammed an outlet located in the western part of the lake basin and which is dated to before 105 ka. After 100 ka, a second transgression (C1″) reached 1730/1735 m, possibly related to a younger ignimbrite flow, in association with high water inflow (warm and/or wetter conditions). The two younger transgressions reached 1700–1705 m. The first one (C2′) is dated to 26–24.5 cal. ka BP and the second one (C2″) to 21–20 cal. ka BP. Available data suggest that the long‐term lake‐level changes responded mainly to climate oscillations. Additional events such as river captures caused by volcanic falls filling valleys, tectonism, erosion and karstic diversion may have impacted these long‐term lake‐level changes. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Response of testate amoeba assemblages to environmental and climatic changes during the Lateglacial–Holocene transition at Lake Lautrey (Jura Mountains,eastern France)     

Adeline A. J. Wall  Michel Magny  Edward A. D. Mitchell  Boris Vannière  Daniel Gilbert 《第四纪科学杂志》2010,25(6):945-956

We tested the response of lacustrine testate amoebae (thecamoebians) to climate and environmental changes for the Lateglacial–Holocene transition. The palaeoenvironmental history of the study site (Lake Lautrey, Jura Mountains, eastern France) was previously established based on high‐resolution multi‐proxy studies of the same core. The present study is characterised by a high taxonomic resolution (54 taxa), inclusion of small species (down to 25 µm) and high total counts (>500 individuals per sample on average). Changes in the composition of testate amoeba assemblages (dominant species and assemblage structure), as well as in the accumulation rate (tests cm^?2 a^?1), corresponded to major climatic phases (i.e. Oldest Dryas, Bølling–Allerød Interstadial, Younger Dryas, Preboreal) as well as changes in organic matter inputs. Furthermore, decreases in the accumulation rate characterised minor short‐lived cooling events, such as Older Dryas event or Gerzensee oscillation. However, the Preboreal oscillation, which was well registered by other proxies at Lake Lautrey, could not be recognised in the testate amoeba record. This work demonstrates that lacustrine testate amoebae can be used for palaeoclimatic and palaeoecological reconstructions. Nevertheless, a better understanding of the relation between climate, organic matter and lacustrine testate amoebae requires further high‐resolution studies based on multi‐proxy approaches and the development of appropriate modern analogues. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

"Risk-Based Corrective Fiction" by Benjamin Ross     

Michel Martin 《Ground water》2000,38(4):485-485

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