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排序方式: 共有276条查询结果,搜索用时 15 毫秒
271.
272.
Michelle T.H. van Vliet Wietse H.P. Franssen John R. Yearsley Fulco Ludwig Ingjerd Haddeland Dennis P. Lettenmaier Pavel Kabat 《Global Environmental Change》2013,23(2):450-464
Climate change will affect hydrologic and thermal regimes of rivers, having a direct impact on freshwater ecosystems and human water use. Here we assess the impact of climate change on global river flows and river water temperatures, and identify regions that might become more critical for freshwater ecosystems and water use sectors. We used a global physically based hydrological-water temperature modelling framework forced with an ensemble of bias-corrected general circulation model (GCM) output for both the SRES A2 and B1 emissions scenario. This resulted in global projections of daily river discharge and water temperature under future climate. Our results show an increase in the seasonality of river discharge (both increase in high flow and decrease in low flow) for about one-third of the global land surface area for 2071–2100 relative to 1971–2000. Global mean and high (95th percentile) river water temperatures are projected to increase on average by 0.8–1.6 (1.0–2.2) °C for the SRES B1–A2 scenario for 2071–2100 relative to 1971–2000. The largest water temperature increases are projected for the United States, Europe, eastern China, and parts of southern Africa and Australia. In these regions, the sensitivities are exacerbated by projected decreases in low flows (resulting in a reduced thermal capacity). For strongly seasonal rivers with highest water temperatures during the low flow period, up to 26% of the increases in high (95th percentile) water temperature can be attributed indirectly to low flow changes, and the largest fraction is attributable directly to increased atmospheric energy input. A combination of large increases in river temperature and decreases in low flows are projected for the southeastern United States, Europe, eastern China, southern Africa and southern Australia. These regions could potentially be affected by increased deterioration of water quality and freshwater habitats, and reduced water available for human uses such as thermoelectric power and drinking water production. 相似文献
273.
Kathy Lynn John Daigle Jennie Hoffman Frank Lake Natalie Michelle Darren Ranco Carson Viles Garrit Voggesser Paul Williams 《Climatic change》2013,120(3):545-556
American Indian and Alaska Native tribes are uniquely affected by climate change. Indigenous peoples have depended on a wide variety of native fungi, plant and animal species for food, medicine, ceremonies, community and economic health for countless generations. Climate change stands to impact the species and ecosystems that constitute tribal traditional foods that are vital to tribal culture, economy and traditional ways of life. This paper examines the impacts of climate change on tribal traditional foods by providing cultural context for the importance of traditional foods to tribal culture, recognizing that tribal access to traditional food resources is strongly influenced by the legal and regulatory relationship with the federal government, and examining the multi-faceted relationship that tribes have with places, ecological processes and species. Tribal participation in local, regional and national climate change adaption strategies, with a focus on food-based resources, can inform and strengthen the ability of both tribes and other governmental resource managers to address and adapt to climate change impacts. 相似文献
274.
Reservoir sedimentation data and sediment yields from Taiwanese rivers show increased soil erosion in response to both 20th century changes in land use and a more recent increase in typhoon frequency and intensity. Decadal variations of up to 5- to 20-fold in suspended-sediment rating curves demonstrate supply-limited transport and correspond to increased sediment delivery from hillslopes due to changes in land use, regional ground shaking during the Chi-Chi earthquake, and post-2000 changes in typhoon frequency and intensity. While accelerated erosion in central Taiwan after the Chi-Chi earthquake has been documented previously, our results show that periods of increased upland erosion also occurred earlier, in response to 20th century changes in land use. Analyses of rainfall records and typhoon frequency for the period 1900–2009 further point to an island-wide increase in erosion rates corresponding to increased typhoon frequency and intensity after 1990. 相似文献
275.
Michelle Christian 《GeoJournal》2017,82(4):805-821
This paper examines the application of private governance through certification labels and industry initiatives in the tourism industry. These efforts are sold as a way to achieve decent working conditions for tourism workers who participate in global value chains in the global South. The question at hand is, are these mechanisms an effective way to support tourism labor? Specifically, this research documents two main findings. First, I evaluate the programs through a tourism global value chain approach and demonstrate how tour operators use language about sustainability and the certification of accommodation suppliers for brand product differentiation and marketing. My findings demonstrate that these programs do not support tourism workers. Second, even with certification and recommendations, the standards are limited and do not include measures to protect against precarious employment, gendered divisions of labor, and emotional labor demands. Thus, these initiatives do not fully protect tourism workers. Finally, I argue a new governance research approach focused on workers’ rights and empowerment provides insights into achieving a more equitable international tourism landscape. This has implications for a governance analysis focused on rights and ‘synergistic’ governance strategies. 相似文献
276.