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131.
ABSTRACT: Data from long‐term ecosystem monitoring and research stations in North America and results of simulations made with interpretive models indicate that changes in climate (precipitation and temperature) can have a significant effect on the quality of surface waters. Changes in water quality during storms, snowmelt, and periods of elevated air temperature or drought can cause conditions that exceed thresholds of ecosystem tolerance and, thus, lead to water‐quality degradation. If warming and changes in available moisture occur, water‐quality changes will likely first occur during episodes of climate‐induced stress, and in ecosystems where the factors controlling water quality are sensitive to climate variability. Continued climate stress would increase the frequency with which ecosystem thresholds are exceeded and thus lead to chronic water‐quality changes. Management strategies in a warmer climate will therefore be needed that are based on local ecological thresholds rather than annual median condition. Changes in land use alter biological, physical, and chemical processes in watersheds and thus significantly alter the quality of adjacent surface waters; these direct human‐caused changes complicate the interpretation of water‐quality changes resulting from changes in climate, and can be both mitigated and exacerbated by climate change. A rigorous strategy for integrated, long‐term monitoring of the ecological and human factors that control water quality is necessary to differentiate between actual and perceived climate effects, and to track the effectiveness of our environmental policies.  相似文献   
132.
本文调查了可持续建筑业的社会形势,特别是发展中国家的可持续建筑业,一个有社会责任感的建筑产业,就是一个在保护劳工免受负面影响的同时努力加强正面影响作用的产业,这要求遵守劳动标准,正如"国际劳工组织(ILO)协定"和国家立法所表达的那样,志愿行动已经做出了积极的贡献,但是严格的计划将要求每一个人依照相同的游戏规则,要做到如此,全体利益相关者确定的统一行动是十分必要的,一个新的"社会责任感建设投资"行动,由国际劳工组织发起,它将把政府代表,雇主,工人和其他主要建筑利益相关者聚在一起,其目的是要制定战略和行动计划,以加强建筑作业中关键劳动标准的贯彻,以及推动建筑部门的生产性就业.  相似文献   
133.
Lakeshore development in Vilas County, northern Wisconsin (USA) is heterogeneous, ranging from lakes that are surrounded by homes and commercial establishments to lakes that have no buildings on their shorelines. Development in this recreational area has increased, and since the 1960s over half of new homes have been built on the lakeshore. We examined building density around lakes in relationship to 11 variables, including in-lake, shoreline, and social characteristics. Buildings in many parts of northern Wisconsin tend to be concentrated around shorelines; in Vilas County 61% of all medium-sized buildings (our proxy for residential development) on private land were ≤100 m of a lake. The probability of development on a lake was largely related to lake surface area, with larger, more accessible lakes showing a higher probability of development. Building density along shorelines varied with travel cost, lake surface area, presence of wetlands, and extent of public land ownership. Building density was greater on larger, more accessible lakes that were surrounded by forest (as opposed to wetlands) and public lands. Gaining a more precise understanding of human settlement patterns can help direct planning and resource protection efforts to lakes most likely to experience future development.  相似文献   
134.
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