共查询到20条相似文献，搜索用时 241 毫秒
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《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(3-4):165-174
The behaviour of the ice-dammed lake, Strupvatnet, Troms County, Norway, is described. Past observations are noted and related to observations in 1959 and to other ice-dammed lakes. Mechanisms for opening and maintaining water flow during a ‘hlaup’ are discussed. It is considered that Liestol's melt widening process operates after initiation by a pressure gradient across the dam. The lake and the internal drainage system of the glacier are thus linked. There is no evidence of lifting of the ice dam at Strupbreen. 相似文献
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《Urban geography》2013,34(2):120-138
This paper explores how the rise of global industrialization has altered the internal complexion of Ciudad Juárez, Chihuahua, the largest and fastest growing of Mexico's northern border cities. First, we trace the political-economic history of Ciudad Juárez and other northern Mexican border cities in order to understand the context of rapid industrialization. Second, we document the dimensions of industrialization by tracing historic trends in population growth, industrial employment, and land-use change. Third, a deprivation index is developed to evaluate the effects of industrialization on quality-of-life at the neighborhood scale in Ciudad Juárez. Deprivation indices are calculated for 266 AGEBs (Mexican geostatistical districts) for the years 1990 and 1995, and changes in levels of deprivation are monitored over time. The analyses show that Ciudad Juárez has experienced unprecedented growth that altered the form, function, and social complexion of the city. 相似文献
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Construction land is the leading carrier of human activities such as production and living. Evaluating the construction land suitability(CLS) on the Qinghai-Tibet Plateau(QTP) holds significant implications for harmonizing the relationship between ecological protection and human activity and promoting population and industry layout optimization. However, no relevant studies provide a complete CLS assessment of the QTP. In this study, we developed a model-based CLS evaluation framework coupling o... 相似文献
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Sanjaya Gurung Bikas C. Bhattarai Rijan B. Kayasth Dorothea Stumm Sharad P. Joshi Pradeep K. Mool 《寒旱区科学》2016,8(4):311-318
Although Himalayan glaciers are of particular interest in terms of future water supplies, regional climate changes, and sea-level rises, little is known about them due to lack of reliable and consistent data. There is a need for monitoring these glaciers to bridge this knowledge gap and to provide field measurements necessary to calibrate and validate the results from different remote sensing operations. Therefore, glaciological observations have been carried out by the Cryosphere Monitoring Project(CMP) since September 2011 on Rikha Samba Glacier in Hidden valley, Mustang district in western Nepal in order to study its annual mass balance. This paper presents the first results of that study. There are 10 glaciers in Hidden Valley, named G1, G2, G3, up to G10. Of these, G5 is the Rikha Samba Glacier, which has the largest area(5.37 km2) in this valley and the highest and lowest altitudes(6,476 and 5,392 m a.s.l., respectively). The glacier mass balance discussed in this paper was calculated using the glaciological method and the equilibrium line altitude(ELA). The glacier showed a negative annual point mass balance along the longitudinal profile of its lower part from September 10, 2011 to October 3, 2012. Stake measurements from October 4, 2012 to September 30, 2013 indicated a negative areal average of annual mass balance-0.088±0.019 m w.e. for the whole glacier. Based on these observations, the ELA of the Rikha Samba Glacier is estimated at 5,800 m a.s.l. in 2013. This negative balance may be due to rising air temperatures in the region, which have been incrementally rising since 1980 accompanied by little or no significant increase in precipitation in that period. The negative mass balance confirms the general shrinking trend of the glacier. 相似文献
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Georges G. Cravins 《The Professional geographer》2013,65(1):138-141
The spatial correlation, or colocation, of two or more variables is a fundamental issue in geographical analysis but has received much less attention than the spatial correlation of values within a single variable, or autocorrelation. A recent paper by Leslie and Kronenfeld (2011) contributes to spatial correlation analysis in its development of a colocation statistic for categorical data that is interpreted in the same way as a location quotient, a frequently used measure in human geography and other branches of regional analysis. Geographically weighted colocation measures for categorical data are further developed in this article by generalizing Leslie and Kronenfeld's global measure as well as specifying a local counterpart for each global statistic using two different types of spatial filters: fixed and adaptive. These geographically weighted colocation quotients are applied to the spatial distribution of housing types to demonstrate their utility and interpretation. 相似文献
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At Admiralty Bay of central King George Island, Keller Peninsula, Ull-man Spur and Point Hennequin are main Tertiary volcanic terranes. Field investigation and isotopic datings indicate that, there occurred three periods of eruptions ( three volcanic cycles) and accompanying N-toward migration of the volcanic center on Keller Peninsula. After the second period of eruptions, the crater collapsed and a cal-dera was formed, then later eruptions were limited at the northern end of the peninsula and finally migrated to Ullman Spur. Thus Keller Peninsula is a revived caldera, and its volcanism migrated toward E with time. Point Hennequin volcanism happened more or less simultaneously with the above two areas, but has no clear relation in chemical evolution with them, frequently it belongs to another independent volcanic center. 相似文献
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Roland Pape 《Norsk geografisk tidsskrift. Norwegian journal of geography》2016,70(4):230-246
Due to increasing anthropogenic habitat alteration, fragmentation, and loss, the analysis of how, when, and why animals select particular habitats has become a central issue in ecology and biogeography. Animals adapt to spatiotemporal variability in resources either by tracking these resources or by plasticity in behavior to cover their needs, leading to three important implications: movement, temporal variation, and individual trade-offs leading to intra-species variability, all of which are directly linked to the use of space by animals. Based on GPS-tracking of domesticated reindeer in southern Norway, the authors addressed these issues by analyzing movement patterns and space use simultaneously across different temporal and organizational scales. Emerging information about the space use by reindeer was found explicitly linked to scaling relations, reflecting the matter of scale as having important functional implications rather than solely being a technical question of extent and resolution. Adding movement into the analysis of space use further advances the necessary functional perspective on space use. The authors conclude that scaling not only space but also time and the organizational level, in combination with accounting for different behavioral states, brings biogeography closer to a process-based view, rather than solely pattern-based view. 相似文献
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Crime is both a factual and perceptual component of the urban landscape, seemingly both a societal pathology and the consequence of economic disparity between social groups. Crime has a spatial structure that can be revealed by mapping. Urban crime has a spatial multiplier effect that changes the values and perceptions of how people see urban space, and which jeopardizes the quality of life of a city's inhabitants. In this research we examine the question of whether the geography of actual criminal acts is echoed by peoples' perceptions of crime, what might be termed their “spaces of fear”. We ask how the fear of crime is associated with reported urban crime. Urban crime incidents have been increasing in Viçosa, Minas Gerais, Brazil. We assembled crime information about Viçosa from two sources: first, crime as reported to the police and second, crime as perceived by city residents and measured by surveys and interviews. Reported criminal acts reveal a clustered geography, focusing particularly on the Downtown area, where there is a concentration of urban wealth and potential victims are more numerous. Offenses against property were focused on Downtown, while offenses against the person were located mostly in peripheral areas. The widespread feeling of insecurity in the city's neighborhoods, reflecting the fear of becoming a victim of violence and crime, was common throughout the city. Results confirmed the conclusion of past studies showing that the fear of violence and crime are not directly related to increasing numbers of criminal reports. Sites with higher incidence of crimes are not places with higher levels of fear. Rather than being geographically explainable “spaces of fear”, the spatial distribution of the fear of violence and crime appears to be unrelated in Viçosa, and neither is clustered or dispersed in any measurable way. 相似文献
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Andrew R. Goetz 《The Professional geographer》2013,65(2):298-300
This article analyzes the interrelationship among resource consumption, sociospatial justice, and what is popularly known as global warming by interrogating the ecological footprint of professional geographers, especially in terms of their conference-going involving air travel. In this spirit, the article introduces and employs the concepts of ecological privilege (as well as its inextricably related antithesis, ecological disadvantage) and dys-ecologism as a way to understand the roots and implications of professional geographers’ fossil fuel use and those of globally advantaged classes more broadly. To illustrate this, the article measures the flight-related ecological footprint of the 2011 annual meeting of the Association of American Geographers (AAG) in Seattle, Washington. In doing so, the article examines how professional geographers, in the form of the AAG, have responded to their travel-related ecological footprint. It thus highlights the importance of scrutinizing the complex and dynamic interrelationships among consumption; associated socioecological benefits and detriments and their systemic manifestations; and hierarchy-related and power-infused categories of race, class, and nation—and their spatialities. 相似文献
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Michael H. Finewood 《The Professional geographer》2013,65(3):468-470
California sage scrub (CSS) is a highly threatened vegetation community in coastal Southern California, 90 percent of which has been lost. Understanding CSS recovery is critical to its survival. This study compares long-term effects of grazing, cultivation, and mechanical disturbance in Southern California by tracking the extent of exotic grassland in two valleys in the Santa Monica Mountains over sixty years using aerial image analysis. Native shrubs returned to the grazed valley over one and one-half times faster than they did in the cultivated valley. Cultivation might result in a type conversion of CSS to exotic annual grassland that resembles a new steady state. 相似文献
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Trevor Fuller PhD student 《The Professional geographer》2013,65(2):272-274
A relatively simple modeling approach for estimating spatially distributed surface energy fluxes was applied to two small watersheds, one in a semi-arid climate region and one in a sub-humid region. This approach utilized a combination of ground-based meteorological data and remotely sensed data to estimate ‘instantaneous’ surface energy fluxes at the time of the satellite or aircraft overpasses. The spatial resolution in the watershed grid cells, which was on the order of 100-400 km, was selected to be compatible with ground measurements used for validation. The model estimates of surface energy fluxes compared well with ground-based measurements of surface flux (typically within approximately 40 Wm?2). The model accuracy may be slightly less for bare soil surfaces due to an overestimation of the soil heat flux. In addition to demonstrating the feasibility of computing spatially distributed values of surface energy fluxes, these maps were used to qualitatively infer the dominant factors controlling the energy fluxes for the time period shortly following precipitation events in the basins. For the semi-arid watershed, values of sensible heat flux varied considerably over the watershed and displayed a pattern very similar to that of the spatially variable cumulative precipitation for at least one to eight days prior to the image acquisition. Due to the large fraction of exposed bare soil in a semi-arid ecosystem, even very small precipitation events had a strong influence on the pattern of sensible heat fluxes observed shortly after the event (less than 24 hours). For the sub-humid watershed, the fluxes tended to be more uniform across the watershed, and were influenced by a combination of precipitation total and land cover type. 相似文献
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Ramesh Dhussa 《The Professional geographer》2013,65(2):312-313
In this article, we first replicate and then adapt an existing index of social vulnerability to hazard developed for the United States to a non-U.S. context. We construct indexes for Norwegian municipalities, describe the adjustment process, and compare the replicated and adapted assessments. Our results indicate only a moderate correlation between the replicated and adapted vulnerability indexes and for several municipalities the difference between the indexes is considerable. This demonstrates that context matters and that indexes of vulnerability need to be adapted rather than replicated. To facilitate such adaption processes, we identify three types of accommodation: conceptual, technical, and geographic. 相似文献
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Heike Jöns 《The Professional geographer》2017,69(4):670-682
This article examines the role of early female academics at the University of Cambridge in the production and dissemination of knowledge between 1926 and 1955. A statistical comparison of women's use of academic leave of absence with that of their male colleagues reveals that, across disciplines, women were less integrated into (inter)national knowledge networks and thus less visible in their epistemic communities than men because women focused their academic leaves more on research, rarely attended conferences, traveled overseas less often than men, and went more frequently to destinations within Europe than the United States as the new economic hegemon. Biographical case studies of these early female academics demonstrate the importance, variously, of their upper middle-class background, academic excellence, and familial and nonfamilial patronage in developing their careers, overcoming multiple hurdles, and producing intellectual contributions of equal quality to that of their male peers. Conceptually, this article calls for the inclusion of academic travelers from disciplines other than geography into feminist histories of geographical knowledge and argues that rather than stereotyping gender differences, greater comparative research on the experiences of female and male academics is needed to understand the mechanisms of gender inequality within the university. 相似文献
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Seed germination was compared among wild, in situ-managed (wild plants let standing in areas cleared for agriculture), and cultivated populations of the columnar cacti Stenocereus pruinosus, Polaskia chichipe, Myrtillocactus schenckii, and Polaskia chende, species representing a gradient from higher to lower management intensity, respectively. We hypothesized that seeds from cultivated populations have higher water requirements to germinate than seeds of other populations, and that such difference is stronger in species more intensely managed. Germination was evaluated under water potential treatments at 0.0, ?0.2, and ?0.4 MPa. Interspecific differences were identified; germination rates markedly decreased in S. pruinosus and P. chichipe as water potential reduced. M. schenckii seeds germinated better at ?0.2 MPa, and seeds of P. chende in all treatments. Seed germination of wild and cultivated populations was similar in all cases and, therefore, at the population level domestication does not appear to have influenced variations in germination of the studied cacti species. However, experiments to test whether germination of seeds from plants with clear signs of domestication differs with seeds from other plants and their differential germination and seedling survival in wild, in situ-managed and cultivated environments could help to precise the influence of domestication on these plants. 相似文献
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