Moving beyond the catchment scale: Value and opportunities in large-scale hydrology to understand our changing world     

Daniel G. Kingston  Nicolas Massei  Bastien Dieppois  David M. Hannah  Andreas Hartmann  David A. Lavers  Jean-Philippe Vidal 《水文研究》2020,34(10):2292-2298

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GIS Investigation of the relationship of sex and season on the population distribution of common bottlenose dolphins (Tursiops truncatus) in Charleston,South Carolina     

Hannah Bouchillon  Norman S. Levine  Patricia A. Fair 《International journal of geographical information science》2020,34(8):1552-1566

ABSTRACT

The Charleston Estuarine System Stock (CESS) of common bottlenose dolphins (Tursiops truncatus) has been the focus of population monitoring for the past 20 years. Photo-id studies have determined abundance and survival estimates for this population, which exhibits high site fidelity in this area. However, fine-scale distribution, utilization patterns, and the driving forces behind these patterns are lacking. Using historical photo-id data and a novel application of geographic information system (GIS) analysis, the present study identified core use areas within Charleston Harbor, as well as patterns specific to sexes and seasons. Photo-id data of 319 dolphins sighted 11 times or more during 2004–2009 were analyzed. Heat maps were developed to examine spatial distributions using kernel density estimates (KDE) and were compared between sexes and seasons. Multiple high-density core use areas were identified for this population, with the most noteworthy near the mouth of the harbor toward the Atlantic Ocean. Fine-scale distribution varied across sexes, as well as seasons. Some areas were identified as more specifically inhabited by one sex, while other areas overlapped between sexes. Females were more tightly concentrated within their distribution while males were more dispersed. Although population distribution varied across seasons, sex distributions remained.  相似文献   

Practicing community geography in times of crisis     

Shannon  Jerry  Torres  Hannah  Mariner  Kathryn A.  Hawthorne  Timothy L. 《GeoJournal》2021,87(2):151-157

Community geography emphasizes the centrality of community engagement to socially transformative research. This introduction to a special issue of GeoJournal on community geography outlines how this growing subfield provides a model for collaborative action with the crises of our time, from white supremacy through climate change. As the co-editors of this special issue, we summarize the contents of these 14 articles, grouping them by the shared themes of power, institutional partnerships, pedagogy, and methods.

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Risk perception in small island developing states: a case study in the Commonwealth of Dominica     

Eboh  Hannah  Gallaher  Courtney  Pingel  Thomas  Ashley  Walker 《Natural Hazards》2021,105(1):889-914

Natural Hazards - Small island developing states (SIDS) face high vulnerability to natural hazards; thus, understanding risk perception in SIDS is an essential step toward reducing vulnerability. A...  相似文献   

Large‐scale climatic influences on precipitation and discharge for a British river basin     

David Lavers  Christel Prudhomme  David M. Hannah 《水文研究》2010,24(18):2555-2563

This article aims to identify the large‐scale climate variables that yield significant statistical relationships with precipitation and discharge for a British river basin (Dyfi). Ranked correlation analysis was performed between gridded ERA‐40 atmospheric data and Dyfi precipitation and discharge for individual months. Precipitation and discharge demonstrate significant negative correlation with mean sea level pressure (MSLP). Strongest MSLP correlation areas move from north of Britain in winter to central Britain in summer; this shift is associated with a displacement of geopotential (Z) and zonal wind (U). Movement of significant correlation regions (not captured by the North Atlantic Oscillation Index) highlights the dynamic nature of precipitation and river flow generating weather systems throughout the year. Existence of strong significant correlation shows potential for exploiting large‐scale climate variables in forecasting precipitation and river flow in Britain. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

The western end of the Eoalpine High‐Pressure Belt (Texel unit,South Tyrol / Italy)          下载免费PDF全文

Hannah Pomella  David Flöss  Romed Speckbacher  Peter Tropper  Bernhard Fügenschuh 《地学学报》2016,28(1):60-69

Eclogites in the Texel Unit (Eastern Alps; South Tyrol, Italy) represent the westernmost outcrops of the E–W striking Eoalpine High‐Pressure Belt (EHB). East of the Tauern Window, the EHB forms part of a Cretaceous intracontinental south‐dipping subduction/collision zone; however, the same nappe stack displays a northwest dip at its western end. This prominent change in dip direction gave rise to discussions on the general setting of the Eoalpine collision. Based on our own observations and literature data, we present a new tectonic model for the western end of the EHB. Due to the special situation of this area at the tip of the Southalpine indenter, originally south(east) dipping structures became overturned, and former thrusts appear as normal faults (e.g. Schneeberg fault zone) while former normal faults presently display thrust geometries (e.g. Jaufen fault). Thus, we explain the current configuration with a coherent Eoalpine subduction direction.  相似文献   

Assessing global Sentinel-2 coverage dynamics and data availability for operational Earth observation (EO) applications using the EO-Compass     

Martin Sudmanns  Dirk Tiede  Hannah Augustin  Stefan Lang 《International Journal of Digital Earth》2020,13(7):768-784

ABSTRACT

Sentinel-2 scenes are increasingly being used in operational Earth observation (EO) applications at regional, continental and global scales, in near-real time applications, and with multi-temporal approaches. On a broader scale, they are therefore one of the most important facilitators of the Digital Earth. However, the data quality and availability are not spatially and temporally homogeneous due to effects related to cloudiness, the position on the Earth or the acquisition plan. The spatio-temporal inhomogeneity of the underlying data may therefore affect any big remote sensing analysis and is important to consider. This study presents an assessment of the metadata for all accessible Sentinel-2 Level-1C scenes acquired in 2017, enabling the spatio-temporal coverage and availability to be quantified, including scene availability and cloudiness. Spatial exploratory analysis of the global, multi-temporal metadata also reveals that higher acquisition frequencies do not necessarily yield more cloud-free scenes and exposes metadata quality issues, e.g. systematically incorrect cloud cover estimation in high, non-vegetated altitudes. The continuously updated datasets and analysis results are accessible as a Web application called EO-Compass. It contributes to a better understanding and selection of Sentinel-2 scenes, and improves the planning and interpretation of remote sensing analyses.  相似文献   

Regional climate and atmospheric circulation controls on the discharge of two British rivers, 1974–97     

I. D. Phillips  G. R. McGregor  C. J. Wilson  D. Bower  D. M. Hannah 《Theoretical and Applied Climatology》2003,76(3-4):141-164

Summary ¶The dependence of the discharge (Q) of two contrasting UK rivers (Itchen, Ewe) on concurrent and lagged regional climate (RC) and atmospheric circulation (AC) variations was assessed over the period 1974–97. RC variables used were temperature and precipitation; the AC indicators used were 850hPa water vapour flux anomalies (VF) at five western European stations, and the Arctic (AOI) and North Atlantic Oscillation (NAOI) indices. Correlation analyses were performed to assess Q-RC and Q-AC relationships before two sets of multiple linear regression models were developed to specify monthly Q values from RC and AC. Q-RC associations were generally stronger and more seasonally consistent than Q-AC relationships, with the flow of the Itchen (southern England) and Ewe (northern Scotland) being most sensitive to temperature (TEMP) and precipitation (PPT) respectively. In most months, discharge values of both rivers were positively associated to zonal and vector VF anomalies over the British Isles and northern France, but inversely related to vector VF over Iceland. The AOI and NAOI were significantly related to the Ewes flow only; relationships were strongest in the winter half-year. Monthly AC regression models explained 14.8–81.0% (25.0–90.9%) of the discharge variability of the Itchen (Ewe). Strong AC forcing of the Itchens discharge is confined to the winter (DJF), since the Itchens direct meteorological signal is attenuated by groundwater dynamics in other seasons. Analysis of anomalous flow periods (e.g. 1988–92 and 1995–7) revealed that discharge does not always respond in the same manner to a given RC/AC forcing, as the relationships themselves vary inter-annually as well as between the two rivers.  相似文献   

Comment on the paper by Bernd Lehmann: Molybdenum distribution in Precambrian rocks of the Colorado mineral belt     

H. J. Stein  J. L. Hannah 《Mineralium Deposita》1988,23(3):222-223

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New insights into the heterogeneity of the Tagish Lake meteorite: Soluble organic compositions of variously altered specimens     

Danielle N. Simkus  Jos C. Aponte  Jamie E. Elsila  Robert W. Hilts  Hannah L. McLain  Christopher D. K. Herd 《Meteoritics & planetary science》2019,54(6):1283-1302

The Tagish Lake carbonaceous chondrite exhibits a unique compositional heterogeneity that may be attributed to varying degrees of aqueous alteration within the parent body asteroid. Previous analyses of soluble organic compounds from four Tagish Lake meteorite specimens (TL5b, TL11h, TL11i, TL11v) identified distinct distributions and isotopic compositions that appeared to be linked to their degree of parent body processing (Herd et al. 2011; Glavin et al. 2012; Hilts et al. 2014). In the present study, we build upon these initial observations and evaluate the molecular distribution of amino acids, aldehydes and ketones, monocarboxylic acids, and aliphatic and aromatic hydrocarbons, including compound‐specific δ¹³C compositions, for three additional Tagish Lake specimens: TL1, TL4, and TL10a. TL1 contains relatively high abundances of soluble organics and appears to be a moderately altered specimen, similar to the previously analyzed TL5b and TL11h lithologies. In contrast, specimens TL4 and TL10a both contain relatively low abundances of all of the soluble organic compound classes measured, similar to TL11i and TL11v. The organic‐depleted composition of TL4 appears to have resulted from a relatively low degree of parent body aqueous alteration. In the case of TL10a, some unusual properties (e.g., the lack of detection of intrinsic monocarboxylic acids and aliphatic and aromatic hydrocarbons) suggest that it has experienced extensive alteration and/or a distinct organic‐depleted alteration history. Collectively, these varying compositions provide valuable new insights into the relationships between asteroidal aqueous alteration and the synthesis and preservation of soluble organic compounds.  相似文献