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61.
Water temperature (Tw) is a key determinant of freshwater ecosystem status and cause for concern under a changing climate. Hence, there is growing interest in the feasibility of moderating rising Tw through management of riparian shade. The Loughborough University Temperature Network (LUTEN) is an array of 36 water and air temperature (Ta) monitoring sites in the English Peak District set‐up to explore the predictability of local Tw, given Ta, river reach, and catchment properties. Year 1 of monitoring shows that 84%–94% of variance in daily Tw is explained by Ta. However, site‐specific logistic regression parameters exhibit marked variation and dependency on upstream riparian shade. Perennial spring flows in the lower River Dove also affect regression model parameters and strongly buffer daily and seasonal mean Tw. The asymptote of the models (i.e. maximum expected Tw) is particularly sensitive to groundwater inputs. We conclude that reaches with spring flows potentially offer important thermal refuges for aquatic organisms against expected long‐term warming of rivers and should be afforded special protection. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Kathleen M. Baker Andrew C. Johnson Caitlin N. Callahan Heather L. Petcovic 《制图学和地理信息科学》2016,43(2):176-187
Topographic maps and aerial photographs are particularly useful when geoscientists are faced with fieldwork tasks such as selecting paths for observation, establishing sampling schemes, or defining field regions. These types of images are crucial in bedrock geologic mapping, a cognitively complex field-based problem-solving task. Geologic mapping requires the geologist to correctly identify rock types and three-dimensional bedrock structures from often partial or poor-quality outcrop data while navigating through unfamiliar terrain. This paper compares the walked routes of novice to expert geologists working in the field (n = 66) with the results of a route planning and navigation survey of a similar population of geologists (n = 77). Results show clearly that those geologists with previous mapping experience make quick and decisive determinations about field areas from available imagery and maps, regardless of whether they are or not physically present in the field area. Recognition of geologic features enabled experts to form and verbalize a specific plan for travel through a landscape based on those features. Novices were less likely to develop specific travel route plans and were less likely to identify critical landscape cues from aerial photographs. 相似文献
63.
The Legacy of Jedidiah Morse in Early American Geography Education: Forgotten and/or Forgettable Geographer?
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Despite numerous and significant writings by historians of geography and biographers from other disciplines, and his authorship of the first geography textbooks written in and for the new American republic, most geographers are largely unaware of the contributions of Jedidiah Morse in academic geography. Writings about Morse suggest that he had alienated himself from many of his contemporaries early in his career through his authoritarian brand of Calvinistic republicanism, a perceived contradiction of that style with his entrepreneurial ambitions, his role in the controversial Bavarian Illuminati, and a dispute with a noted New England historian. But subsequent, broader intellectual movements sealed Morse's fate as a forgotten geographer (to most), including the end of the Second Great Awakening, Transcendentalism, Darwinism, and the “new,” process‐based geographical thinking inspired by Carl Ritter, Alexander von Humboldt, and Arnold Guyot. Regardless of the reasons for Morse's lost legacy, his contributions to geographical education are important and should be remembered. 相似文献
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Wasiu Olanrewaju Raji Ifedolapo Gbadesere Obadare Marry Abiodun Odukoya Lukman Mobolaji Johnson 《Arabian Journal of Geosciences》2018,11(7):144
Three years after the oil spillage and pipeline explosion that claimed about 100 human lives at Ijegun Community of Lagos–Nigeria, a combination of carefully designed 2D Electrical Resistivity Profilling and Vertical Electrical Sounding methods was deployed to map and characterise the subsurface around the contaminated site. Data acquired were processed, forward modelled and tomographically inverted to obtain the multi-dimensional resistivity distribution of subsurface. The results of the study revealed high resistivity structures that indocate the presence of contaminant (oil plumes) of different sizes and shapes around the oil leakage site. These high resistivity structures are absent in the tomograms and resistivity-depth slices computed for Iyana—a linear settlement not affected by oil spillage. The five geo-electric layers and the resistivities delineated in the area are the top soil layer, 220–670 Ωm; clayey sand layer, 300–1072 Ωm; top sand layer, 120–328 Ωm; mudstone/shale layer, 25–116 Ωm and the bottom sand layer, 15–69 Ωm. The base of the first four geo-electric layers corresponds to 3.9, 8.4, 27.2 and 34.6 m respectively. The two groundwater aquifers delineated correspond to the third and fifth geo-electric layers. The top aquifer has been infiltrated by oil plumes. The depth penetrated by the oil plume decreases from 32 m to about 24 m across the survey profiles from the two ends. It was concluded that the contaminant plumes from the oil spillage are yet to be completely degraded as at the time of the study. It is recommended that the contaminated site be remediated to remove or reduce the contaminant oil in the subsurface. 相似文献
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GeoJournal - Broad academic interest in measuring social relationships within an urban context has grown over recent decades. Significant research attention is focused on where social synergies... 相似文献
68.
Natural Hazards - Driving after natural disasters entails a substantial amount of stress; therefore, the number of motor vehicle crashes may increase. However, few studies have examined this issue.... 相似文献
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Influence of environmental and prey variables on low tide shorebird habitat use within the Robbins Passage wetlands,Northwest Tasmania 总被引:1,自引:0,他引:1
Shorebirds feed primarily on tidal flats, and their distribution over these flats is influenced by their prey and abiotic factors. These factors act by influencing the distribution and abundance of the prey, or the shorebirds ability to exploit it. The aims of this study were to investigate the low tide foraging distribution of shorebirds at four sites within the Robbins Passage wetlands, and the environmental and invertebrate factors that may influence their distribution. The greatest densities and number of shorebirds were found at Shipwreck Point and East Inlet. The shorebirds within-site distribution was also non-random, with the shorebirds present in greatest densities at the water's edge and low intertidal stratum, although this varied among species. Generally, on a small spatial scale, invertebrate diversity was positively correlated, and seagrass leaf mass was negatively correlated, with shorebird feeding density. On a large spatial scale, invertebrate biomass and seagrass root mass were positively correlated with shorebird feeding density. Invertebrate biomass and seagrass root mass explained 71% of the variance in total shorebird feeding density on the tidal flats. The variation in shorebird feeding density and diversity was therefore partly explained by invertebrate diversity and biomass, as well as the environmental factors seagrass roots and leaf mass and tidal flat area, although the strength of these relationships was influenced by the two different spatial scales of the study. The strength of the relationships between shorebird feeding density and the invertebrate and environmental variables was stronger on a large spatial scale. The presence of seagrass may have influenced shorebird-feeding density by affecting the invertebrate abundance and composition or the shorebirds ability to detect and capture their prey. The area of the tidal flat had opposing effects on the shorebird species. These results can be used to assist in the development of management plans for the Robbins Passage wetlands and the conservation of important shorebird areas. 相似文献