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411.
The growing concerns over the environmental impacts of buildings have led to increasing demands for more environmental friendly buildings and building materials. Hitherto, there are not any comprehensive studies that show the overall environmental impact profiles of building materials and building services components for buildings. This paper intends to bridge this gap by reporting overall lifecycle environmental profiles of buildings as well as the ranking orders of environmental impacts of all the building materials and building services materials and components for commercial buildings. Twenty-five commercial buildings in Hong Kong, which include three Grade A office buildings, four Grade B office buildings, one Grade C office buildings, four retail centers and three hotels, have been selected for our study. Based upon these collected samples, no statistical differences were found in the average lifecycle environmental impacts for different building types despite some minor variations were detected. Subsequently, 10 types of building materials and 10 types of building services components have been identified for their significant lifecycle environmental impacts on commercial buildings. Among all, concrete, reinforcement bar, copper power cables, and copper busbars were ranked to be the four most significant materials or components to the total lifecycle environmental impacts. These should form the major targets for improvements in environmental performance of commercial buildings. 相似文献
412.
Thomas J. Wilbanks Jayant Sathaye 《Mitigation and Adaptation Strategies for Global Change》2007,12(5):957-962
Integrating mitigation and adaptation (M&A) is a practical reality for climate change response policy, despite a range of
conceptual and methodological challenges. Based on the papers in this special issue, some preliminary findings about appropriate
integrated portfolios are offered, along with several implications for climate policy. 相似文献
413.
Adaptation and mitigation strategies in agriculture: an analysis of potential synergies 总被引:3,自引:4,他引:3
Cynthia Rosenzweig Francesco Nicola Tubiello 《Mitigation and Adaptation Strategies for Global Change》2007,12(5):855-873
As climate changes due to rising concentrations of greenhouse gases in the atmosphere, agriculture will be one of the key
human activities affected. Projections show that while overall global food production in the coming decades may keep pace
with the food requirements of a growing world population, climate change might worsen existing regional disparities because
it will reduce crop yields mostly in lands located at lower latitudes where many developing countries are situated. Strategies
to enhance local adaptation capacity are therefore needed to minimize climatic impacts and to maintain regional stability
of food production. At the same time, agriculture as a sector offers several opportunities to mitigate the portion of global
greenhouse gas emissions that are directly dependent upon land use, land-use change, and land-management techniques. This
paper reviews issues of agriculture and climate change, with special attention to adaptation and mitigation. Specifically,
as adaptation and mitigation strategies in agriculture are implemented to alleviate the potential negative effects of climate
change, key synergies need to be identified, as mitigation practices may compete with modifications to local agricultural
practices aimed at maintaining production and income. Under future climate and socio-economic pressures, land managers and
farmers will be faced with challenges in regard to selecting those mitigation and adaptation strategies that together meet
food, fiber and climate policy requirements. 相似文献
414.
415.
Baldauf RW Lane DD Marotz GA Barkman HW Pierce T 《Environmental monitoring and assessment》2002,78(3):213-227
An ambient air quality monitoring network has been establishedusing risk assessment techniques to evaluate adverse health effects from exposures to airborne contaminants. The risk assessment method was compared to traditional methods of establishing air quality monitoring networks: identifying maximumconcentration impacts or maximum total population. Results suggest that the health risk method best predicted the locationof adverse, non-carcinogenic respiratory illnesses during the evaluation period. Spearman Rank Correlation Coefficient, r
s, values obtained using the risk assessment method werestatistically greater than the values obtained using theconcentration and population methods. The concentration methodwas the least accurate predictor of adverse effects. 相似文献
416.
James F. Booker 《Journal of the American Water Resources Association》1995,31(5):889-906
ABSTRACT: A severe sustained drought in the Colorado River Basin would cause economic damages throughout the Basin. An integrated hydrologic-economic-institutional model introduced here shows that consumptive water users in headwaters states are particularly vulnerable to very large shortfalls and hence large damages because their rights are effectively junior to downstream users. Chronic shortfalls to consumptive users relying on diversions in excess of rights under the Colorado River Compact are also possible. Nonconsumptive water uses (for hydropower and recreation) are severely affected during the worst drought years as instream flows are reduced and reservoirs are depleted. Damages to these uses exceeds those to consumptive uses, with the value of lost hydropower production the single largest economic impact of a severe sustained drought. Modeling of alternative policy responses to drought suggests three general policy approaches with particular promise for reducing damages. Consumptive use damages can be reduced by over 90 percent through reallocation from low to high valued uses and through reservoir storage strategies which minimize evaporation losses. Reservoir management to preserve minimum power pool levels for hydropower production (and to maintain reservoir recreation) may reduce damages to these nonconsumptive uses by over 30 percent, but it may increase consumptive use shortfalls. 相似文献
417.
Salt marsh vegetation change in response to tidal restriction 总被引:4,自引:0,他引:4
Vegetation change in response to restriction of the normal tidal prism of six Connecticut salt marshes is documented. Tidal flow at the study sites was restricted with tide gates and associated causeways and dikes for purposes of flood protection, mosquito control, and/or salt hay farming. One study site has been under a regime of reduced tidal flow since colonial times, while the duration of restriction at the other sites ranges from less than ten years to several decades. The data indicate that with tidal restriction there is a substantial reduction in soil water salinity, lowering of the water table level, as well as a relative drop in the marsh surface elevation. These factors are considered to favor the establishment and spread ofPhragmites australis (common reed grass) and other less salt-tolerant species, with an attendant loss ofSpartina-dominated marsh. Based on detailed vegetation mapping of the study sites, a generalized scheme is presented to describe the sequence of vegetation change from typicalSpartina- toPhragmites-dominated marshes. The restoration of thesePhragmites systems is feasible following the reintroduction of tidal flow. At several sites dominated byPhragmites, tidal flow was reintroduced after two decades of continuous restriction, resulting in a marked reduction inPhragmites height and the reestablishment of typical salt marsh vegetation along creekbanks. It is suggested that large-scale restoration efforts be initiated in order that these degraded systems once again assume their roles within the salt marsh-estuarine ecosystem. 相似文献
418.
Wayne T. Swank 《Journal of the American Water Resources Association》1984,20(3):313-321
The atmosphere is a significant source of plant nutrients that partially replenishes losses due to timber harvesting. The relative importance of wet and dry deposition depends upon the specific nutrient and site. Nitrogen in bulk precipitation (wetfall and dryfall) is equivalent to at least 70 percent of the nitrogen incorporated annually in above-ground woody tissues of some temperate hardwood forests. Atmospheric sources of calcium and potassium supply between 20 and 40 percent of the nutrients sequestered in woody increments. Annual nutrient inputs in bulk precipitation can exceed removals associated with sawiog harvest over a rotation period. Atmospheric inputs of nitrogen are only slightly less than hydrologic losses immediately after timber harvesting. The deposition of nutrients is highly variable in both time and space; interpretations of nutrient inputs and forest management impacts require quantification of inputs for a variety of ecosystems over long periods of time. 相似文献
419.
J. C. Day K. C. Bridger S. E. Peet B. F. Friesen 《Journal of the American Water Resources Association》1982,18(2):297-305
ABSTRACT: Biophysical and socioeconomic effects are identified in reservoir, downstream, division channel, and receiving water body areas. Overall, the projects have been socially useful, especially from the perspective of hydroelectric, log driving, and economic development benefits. However selected socially inequitable aspects of the projects and other problems related to erosion, turbidity, multiple resource use, failure to clear trees, and heritage resource losses are identified. Suggestions for planning similar projects are presented. 相似文献
420.
D. C. Williams Charles P. Cartee 《Journal of the American Water Resources Association》1974,10(1):144-152
ABSTRACT Development of community water systems in rural areas through the Farmers Home Administration, U. S. D. A., has been marked since the initiation of the program in the early 1%O's. System development in Mississippi has been very rapid and now numbers the largest among the states excepting Texas. Concurrent with this growth, however, has been a concern for operational quality and efficiency as well as questions of community impacts. The paper is purposed with describing the results of research conducted relative to these areas and methods currently being employed or considered for dealing with problematic items. 相似文献