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261.
Melanie Dickie Geoff G. Sherman Glenn D. Sutherland Robert S. McNay Michael Cody 《Conservation biology》2023,37(2):e14004
Fragmentation of the boreal forest by linear features, including seismic lines, has destabilized predator–prey dynamics, resulting in the decline of woodland caribou (Rangifer tarandus caribou) populations. Restoration of human-altered habitat has therefore been identified as a critical management tool for achieving self-sustaining woodland caribou populations. However, only recently has testing of the response of caribou and other wildlife to restoration activities been conducted. Early work has centered around assessing changes in wildlife use of restored seismic lines. We evaluated whether restoration reduces the movement rates of predators and their associated prey, which is expected to decrease predator hunting efficiency and ultimately reduce caribou mortality. We developed a new method for using cameras to measure fine-scale movement by measuring speed as animals traveled between cameras in an array. We used our method to quantify speed of caribou, moose (Alces alces), bears (Ursus americanus), and wolves (Canis lupus) on treated (restored) and untreated seismic lines. Restoration treatments reduced travel speeds along seismic lines of wolves by 1.38 km/h, bears by 0.55 km/h, and caribou by 1.57 km/h, but did not reduce moose travel speeds. Reduced predator and caribou speeds on treated seismic lines are predicted to decrease encounter rates between predators and caribou and thus lower caribou kill rates. However, further work is needed to determine whether reduced movement rates result in reduced encounter rates with prey, and ultimately reduced caribou mortality. 相似文献
262.
Jinghai Zeng Min Xing Glenn C. England Jing Yan 《Journal of the Air & Waste Management Association (1995)》2018,68(9):945-957
The Beijing Municipal Environmental Protection Bureau (EPB) is considering strengthening the Emission Standard of Air Pollutants for Stationary Gas Turbines, originally published in 2011 (DB11/847–2011), with a focus on reducing nitrogen oxides (NOx) emissions. A feasibility study was conducted to evaluate the current operation of 12 existing combined-cycle gas turbine power plants and the design of two new plants in Beijing and their emission reduction potential, in comparison with a state-of-the-art power plant in California. The study found that best management practices (BMPs) could potentially improve the emission level of the power plants, and should be implemented to minimize emissions under current design characteristics. These BMPs include (1) more frequent tuning of turbine combustors; (2) onsite testing of natural gas characteristics in comparison to turbine manufacturer’s specifics and tuning of turbine to natural gas quality; (3) onsite testing of aqueous ammonia to ensure adequate ammonia concentration in the mixed solution, and the purity of the solution; (4) more careful inspection of the heat recovery steam generator (HRSG), and the selective catalytic reduction (SCR) during operation and maintenance; (5) annual testing of the catalyst coupon on the SCR to ensure catalyst effectiveness; and (6) annual ammonia injection grid (AIG) tuning. The study found that without major modification to the plants, improving the management of the Beijing gas turbine power plants may potentially reduce the current hourly average NOx emission level of 5–10 parts per million (ppm; ranges reflects plant variation) by up to 20%. The exact improvement associated with each BMP for each facility requires more detailed analysis, and requires engagement of turbine, HRSG, and SCR manufacturers. This potential improvement is an important factor to consider when strengthening the emission standard. However, note that with the continuous needs of improving air quality within the area, more expensive control measures, such as retrofitting the turbines or the HRSGs, may be considered.
Implications: This study analyzed the potential emission reductions associated with implementing the best management practices (BMPs) on the combined cycle and cogeneration power plants in Beijing. It determined that implementing the BMPs could potentially achieve up to 580 metric tonnes, or 0.6%, reductions of all NOx emissions in Beijing. Many other cities in China and Asia battling air quality issues may find the information useful in order to evaluate the emission reduction potential of their own gas turbine power plants. 相似文献
263.
Glenn EP Hucklebridge K Hinojosa-Huerta O Nagler PL Pitt J 《Environmental management》2008,41(3):322-335
Arid zone rivers have highly variable flow rates, and flood control projects are needed to protect adjacent property from
flood damage. On the other hand, riparian corridors provide important wildlife habitat, especially for birds, and riparian
vegetation is adapted to the natural variability in flows on these rivers. While environmental and flood control goals might
appear to be at odds, we show that both goals can be accommodated in the Limitrophe Region (the shared border between the
United States and Mexico) on the Lower Colorado River. In 1999, the International Boundary and Water Commission proposed a
routine maintenance project to clear vegetation and create a pilot channel within the Limitrophe Region to improve flow capacity
and delineate the border. In 2000, however, Minute 306 to the international water treaty was adopted, which calls for consideration
of environmental effects of IBWC actions. We conducted vegetation and bird surveys within the Limitrophe and found that this
river segment is unusually rich in native cottonwood and willow trees, marsh habitat, and resident and migratory birds compared
to flow-regulated segments of river. A flood-frequency analysis showed that the existing levee system can easily contain a
100 year flood even if vegetation is not removed, and the existing braided channel system has greater carrying capacity than
the proposed pilot channel. 相似文献
264.
A new framework for environmental assessment is needed because no existing framework explicitly includes all types of environmental
assessments. We propose a framework that focuses on resolving environmental problems by integrating different types of assessments.
Four general types of assessments are included: (1) condition assessments to detect chemical, physical, and biological impairments;
(2) causal pathway assessments to determine causes and identify their sources; (3) predictive assessments to estimate environmental,
economic, and societal risks, and benefits associated with different possible management actions; and (4) outcome assessments
to evaluate the results of the decisions of an integrative assessment. The four types of assessments can be neatly arrayed
in a two-by-two matrix based on the direction of analysis of causal relationships (rows) and whether the assessment identifies
problems or solves them (columns). We suggest that all assessments have a common structure of planning, analysis, and synthesis,
thus simplifying terminology and facilitating communication between types of assessments and environmental programs. The linkage
between assessments is based on intermediate decisions that initiate another assessment or a final decision signaling the
resolution of the problem. The framework is applied to three cases: management of a biologically impaired river, remediation
of a contaminated site, and reregistration of a pesticide. We believe that this framework clarifies the relationships among
the various types of assessment processes and their links to specific decisions. 相似文献
265.
Martin M. Karpiscak Glenn W. France K James DeCook Richard G. Brittain Kennith E. Foster Susan B. Hopf 《Journal of the American Water Resources Association》2001,37(5):1237-1248
ABSTRACT: Casa del Agua (Casa) in suburban Tucson, Arizona, was designed as a residential water conservation facility for applied research, demonstration of operational results, and transfer of technology to the general public. Starting in 1983, an existing residence was located, modified and retrofitted to acquire operational data on residential water use. Modifications included retrofitting existing landscapes and enlarging the rooftop to collect and harvest rainwater; separating blackwater and graywater lines; installing meters, low‐water‐use appliances and fixtures, and underground storage tanks for rainwater and graywater; and creating a public information center. Over the 13‐plus years of actual operation, both the interior and exterior water use research results indicate large reductions in water use can be effected using water‐saving devices andlor harvesting and reusing rainwater and graywater. Casa achieved over a 24 percent reduction in total water use and a 47 percent reduction in municipal water used compared to the typical Tucson residence. Overall water used was comprised of harvested rainwater (10 percent), recycled graywater (20 percent), and municipal water (70 percent). Casa's Information Center was visited by approximately 13,000 people from September 1985 through April 1999 and the research has been featured in local, national, and international media. 相似文献
266.
267.
Christopher J. Herrick Erik D. Goodman Charles A. Guthrie Richard H. Blythe Glenn A. Hendrix Richard L. Smith Jim E. Galloway 《Ecological modelling》1982,15(1):1-28
A model for the accumulation of mercury in four compartments of woodland stream has been set up. The four components considered are sediments, detritus, invertebrates and fish. The model inputs are concentrations of dissolved monomethyl mercury and dissolved inorganic mercury (Hg2+) in the water. The model predicts that some reevaluation of current safe mercury concentrations in water may be needed in order to keep mercury concentrations in fish below current actions levels. 相似文献
268.
269.
Nagler P Glenn EP Hursh K Curtis C Huete A 《Environmental monitoring and assessment》2005,109(1-3):255-274
A vegetation mapping system for change detection was tested at the Havasu National Wildlife Refuge (HNWR) on the Lower Colorado
River. A low-cost, aerial photomosaic of the 4200 ha, study area was constructed utilizing an automated digital camera system,
supplemented with oblique photographs to aid in determining species composition and plant heights. Ground-truth plots showed
high accuracy in distinguishing native cottonwood (Populus fremontii) and willow (Salix gooddingii) trees from other vegetation on aerial photos. Marsh vegetation (mainly cattails, Typha domengensis) was also easily identified. However, shrubby terrestrial vegetation, consisting of saltcedar (Tamarix ramosissima), arrowweed (Pluchea sericea), and mesquite trees (Prosopis spp.), could not be accurately distinguished from each other and were combined into a single shrub layer on the final vegetation
map. The final map took the form of a base, shrub and marsh layer, which was displayed as a Normalized Difference Vegetation
Index map from a Landsat Enhanced Thematic Mapper (ETM+) image to show vegetation intensity. Native willow and cottonwood
trees were digitized manually on the photomosaic and overlain on the shrub layer in a GIS. By contrast to present, qualitative
mapping systems used on the Lower Colorado River, this mapping system provides quantitative information that can be used for
accurate change detection. However, better methods to distinguish between saltcedar, mesquite, and arrowweed are needed to
map the shrub layer. 相似文献
270.
Neilson MA Painter DS Warren G Hites RA Basu I Weseloh DV Whittle DM Christie G Barbiero R Tuchman M Johannsson OE Nalepa TF Edsall TA Fleischer G Bronte C Smith SB Baumann PC 《Environmental monitoring and assessment》2003,88(1-3):103-117
The Great Lakes Water Quality Agreement stipulates that the Governments of Canada and the United States are responsible for restoring and maintaining the chemical, physical and biological integrity of the waters of the Great Lakes Basin Ecosystem. Due to varying mandates and areas of expertise, monitoring to assess progress towards this objective is conducted by a multitude of Canadian and U.S. federal and provincial/state agencies, in cooperation with academia and regional authorities. This paper highlights selected long-term monitoring programs and discusses a number of documented ecological changes that indicate the present state of the open and nearshore waters of the Great Lakes. 相似文献