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131.
132.
David L. Strayer Stuart E. G. Findlay Daniel Miller Heather M. Malcom David T. Fischer Thomas Coote 《Aquatic Sciences - Research Across Boundaries》2012,74(3):597-610
The shore zones of the Hudson River, like those of many developed waterways, are highly varied, containing a mix of seminatural and highly engineered shores. Our goal was to document the biodiversity supported by different kinds of shore zones in the Hudson. We chose six common types of shore zones, three of them ??natural?? (sand, unconsolidated rock, and bedrock), and three of them engineered (riprap, cribbing, and bulkheads). We measured selected physical characteristics (shore zone width, exposure, substrate roughness and grain size, shoreline complexity) of three examples of each of these shore types, and also sampled communities of terrestrial plants, fishes, and aquatic and terrestrial invertebrates. Community composition of most taxa differed across shore types, and frequently differed between wide, sheltered shores and narrow, exposed shores. Alien plant species were especially well represented along engineered shores. Nevertheless, a great deal of variation in biological communities was not explained by our six-class categorization of shore zones or the physical variables that we measured. No single shore type supported the highest values of all kinds of biodiversity, but engineered shore zones (especially cribbing and bulkheads) tended to have less desirable biodiversity characteristics than ??natural?? shore zones. 相似文献
133.
134.
David L. Strayer Stuart E. G. Findlay 《Aquatic Sciences - Research Across Boundaries》2010,72(2):127-163
Freshwater shore zones are among the most ecologically valuable parts of the planet, but have been heavily damaged by human
activities. Because the management and rehabilitation of freshwater shore zones could be improved by better use of ecological
knowledge, we summarize here what is known about their ecological functioning. Shore zones are complexes of habitats that
support high biodiversity, which is enhanced by high physical complexity and connectivity. Shore zones dissipate large amounts
of physical energy, can receive and process extraordinarily high inputs of autochthonous and allochthonous organic matter,
and are sites of intensive nutrient cycling. Interactions between organic matter inputs (including wood), physical energy,
and the biota are especially important. In general, the ecological character of shore zone ecosystems is set by inputs of
physical energy, geologic (or anthropogenic) structure, the hydrologic regime, nutrient inputs, the biota, and climate. Humans
have affected freshwater shore zones by laterally compressing and stabilizing the shore zone, changing hydrologic regimes,
shortening and simplifying shorelines, hardening shorelines, tidying shore zones, increasing inputs of physical energy that
impinge on shore zones, pollution, recreational activities, resource extraction, introducing alien species, changing climate,
and intensive development in the shore zone. Systems to guide management and restoration by quantifying ecological services
provided by shore zones and balancing multiple (and sometimes conflicting) values are relatively recent and imperfect. We
close by identifying leading challenges for shore zone ecology and management. 相似文献
135.
136.
Neil Stuart 《International journal of geographical information science》2013,27(6):601-602
In this paper, we examine the applicability of spatial optimization as a generative modelling technique for sustainable land‐use allocation. Specifically, we test whether spatial optimization can be used to generate a number of compromise spatial alternatives that are both feasible and different from each other. We present a new spatial multiobjective optimization model, which encourages efficient utilization of urban space through infill development, compatibility of adjacent land uses, and defensible redevelopment. The model uses a density‐based design constraint developed by the authors. The constraint imposes a predefined level of consistent neighbourhood development to promote contiguity and compactness of urban areas. First, the model is tested on a hypothetical example. Further, we demonstrate a real‐world application of the model to land‐use planning in Chelan, a small environmental amenity town in the north‐central region of the State of Washington, USA. The results indicate that spatial optimization is a promising method for generating land‐use alternatives for further consideration in spatial decision‐making. 相似文献
137.
Tsunami damage to coastal defences and buildings in the March 11th 2011 M
w
9.0 Great East Japan earthquake and tsunami 总被引:2,自引:0,他引:2
Stuart Fraser Alison Raby Antonios Pomonis Katsuichiro Goda Siau Chen Chian Joshua Macabuag Mark Offord Keiko Saito Peter Sammonds 《Bulletin of Earthquake Engineering》2013,11(1):205-239
On March 11th 2011 a M w 9.0 mega-thrust interface subduction earthquake, the Great East Japan Earthquake, occurred 130 km off the northeast coast of Japan in the Pacific Ocean at the Japan Trench, triggering tsunami which caused damage along 600 km of coastline. Observations of damage to buildings (including vertical evacuation facilities) and coastal defences in Tōhoku are presented following investigation by the Earthquake Engineering Field Investigation Team (EEFIT) at 10 locations in Iwate and Miyagi Prefectures. Observations are presented in the context of the coastal setting and tsunami characteristics experienced at each location. Damage surveys were carried out in Kamaishi City and Kesennuma City using a damage scale for reinforced concrete (RC), timber and steel frame buildings adapted from an earlier EEFIT tsunami damage scale. Observations show that many sea walls and breakwaters were overtopped, overturned, or broken up, but provided some degree of protection. We show the extreme variability of damage in a local area due to inundation depth, flow direction, velocity variations and sheltering. Survival of many RC shear wall structures shows their high potential to withstand local earthquake and significant tsunami inundation but further research is required into mitigation of scour, liquefaction, debris impact, and the prevention of overturning failure. Damage to steel and timber buildings are also discussed. These observations are intended to contribute to mitigation of future earthquake and tsunami damage by highlighting the key features which influence damage level and local variability of damage sustained by urban coastal infrastructure when subjected to extreme tsunami inundation depths. 相似文献
138.
Magnetic separation has been recognized as an important property for the simple deployment of micro and sub‐microparticles into solution in the field of water treatment. Many materials with desirable properties for water decontamination are hindered due to the difficulty inherent in removing them from solution post‐treatment. By securing these materials to magnetic compounds, this important issue can be solved as removing active materials from wastewater requires only the application of a magnetic field. This review article presents and discusses many recent technologies, in the form of patents, which exploit the property of magnetic separation for advanced water treatment, including methods of adsorbing pollutants from wastewater and magnetically separating them, as well as methods of deploying active materials for the degradation of contaminants, then magnetically retrieving these catalysts. The requirement for advanced wastewater treatment methods becomes more essential as new, persistent contaminants arise as a result of pharmaceuticals, pesticides and industrial processes which cannot be addressed by traditional water treatment procedures. Magnetic separation promises to be a critical factor in these advanced methods, allowing the safe deployment of active materials which would otherwise be unusable, opening the gate to more efficient, economic and environmentally friendly water purification. 相似文献
139.
Katia Sanhueza-Pino Oliver Korup Ralf Hetzel Henry Munack Johannes T. Weidinger Stuart Dunning Cholponbek Ormukov Peter W. Kubik 《Quaternary Research》2011,76(3):295-304
Numerous large landslide deposits occur in the Tien Shan, a tectonically active intraplate orogen in Central Asia. Yet their significance in Quaternary landscape evolution and natural hazard assessment remains unresolved due to the lack of "absolute" age constraints. Here we present the first 10Be exposure ages for three prominent (> 107 m3) bedrock landslides that blocked major rivers and formed lakes, two of which subsequently breached, in the northern Kyrgyz Tien Shan. Three 10Be ages reveal that one landslide in the Alamyedin River occurred at 11–15 ka, which is consistent with two 14C ages of gastropod shells from reworked loess capping the landslide. One large landslide in Aksu River is among the oldest documented in semi-arid continental interiors, with a 10Be age of 63–67 ka. The Ukok River landslide deposit(s) yielded variable 10Be ages, which may result from multiple landslides, and inheritance of 10Be. Two 10Be ages of 8.2 and 5.9 ka suggest that one major landslide occurred in the early to mid-Holocene, followed by at least one other event between 1.5 and 0.4 ka. Judging from the regional glacial chronology, all three landslides have occurred between major regional glacial advances. Whereas Alamyedin and Ukok can be considered as postglacial in this context, Aksu is of interglacial age. None of the landslide deposits show traces of glacial erosion, hence their locations and 10Be ages mark maximum extents and minimum ages of glacial advances, respectively. Using toe-to-headwall altitude ratios of 0.4–0.5, we reconstruct minimum equilibrium-line altitudes that exceed previous estimates by as much as 400 m along the moister northern fringe of the Tien Shan. Our data show that deposits from large landslides can provide valuable spatio-temporal constraints for glacial advances in landscapes where moraines and glacial deposits have low preservation potential. 相似文献
140.
Ali Al-Lazki Cindy Ebinger Michael Kendall George Helffrich Sylvie Leroy Christel Tiberi Graham Stuart Khalfan Al-Toobi 《Arabian Journal of Geosciences》2011,5(5):925-934
In this study, we used data recorded by two consecutive passive broadband deployments on the Gulf of Aden northern margin, Dhofar region, Sultanate of Oman. The objective of these deployments is to map the young eastern Gulf of Aden passive continental margin crust and upper mantle structure and rheology. In this study, we use shear-wave splitting analysis to map lateral variations of upper mantle anisotropy beneath the study area. In this study, we found splitting magnitudes to vary between 0.33 and 1.0 s delay times, averaging about 0.6 s for a total of 17 stations from both deployment periods. Results show distinct abrupt lateral anisotropy variation along the study area. Three anisotropy zones are identified: a western zone dominated by NW–SE anisotropy orientations, an eastern zone dominated with NE–SW anisotropy orientations, and central zone with mixed anisotropy orientations similar to the east and west zones. We interpret these shorter wavelength anisotropy zones to possibly represent fossil lithospheric mantle anisotropy. We postulate that the central anisotropy zone may be representing a Proterozoic suture zone that separates two terranes to the east and west of it. The anisotropy zones west and east were being used indicative of different terranes with different upper mantle anisotropy signatures. 相似文献