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The infamous "Sydney Tar Ponds" are well known as one of the largest toxic waste sites of Canada, due to almost 100 years of steelmaking in Sydney, a once beautiful and peaceful city located on the east side of Cape Breton Island, Nova Scotia. This article begins with a contextual overview of the Tar Ponds issue including a brief introduction and history and summaries of the effects on the earth, the people, and the biotic community (animals and vegetation). Then the authors talk about the STS analysis approach, namely, a discussion of six systems to indicate what has been brought to the earth and mankind by technology and modern industry. The remaining part of the article describes the difficulties confronting China, some of which are similar to the ones Canada faces as a result of the Tar Ponds contamination, and summarizes some of the experiences at Tar Ponds and the lessons China can learn from Tar Ponds. (Contains 10 notes.)

Hydrosedimentary connectivity is a key concept referring to the potential fluxes of water and sediment moving throughout a catchment. In forested catchments, these fluxes are prone to alterations caused by anthropogenic and natural disturbances. In this study, we modelled the interannual spatiotemporal evolution of hydrosedimentary connectivity influenced by forest cover change over the last four decades in the Mont‐Louis catchment, a medium snow‐dominated mountainous catchment in eastern Canada, which had 62% of its total surface affected by forest disturbances (mainly logging, but also wildfires and diseases) between 1979 and 2017. Using a geomorphometric index of connectivity (IC) and a historical forest cover database, we produced one IC map per year that considered anthropogenic and natural disturbances affecting the forest cover of the studied catchment. To account for vegetation recovery, forest disturbances were weighted with local hydrological recovery rates. Over the four decades, the mean IC of the Mont‐Louis catchment dramatically increased by 35% in response to different types of disturbances. The spatial evolution of IC over the whole catchment and at the sub‐catchment scale revealed that disturbance location has a strong influence on hydrosedimentary connectivity to the main channel. Our results also highlight the sharp contrast between IC computed from topography‐based impedance to those computed from vegetation‐based impedance. Forest disturbances appear to connect hillslopes with the hydrological network by producing pathways for sediment and water. Finally, the proposed reproducible framework could be useful for predicting the potential impact of harvesting and preventing damage to fish habitat and sensitive river reaches. [ABSTRACT FROM AUTHOR]

The list below specifies doctoral degrees conferred by U.S. and Canadian universities during academic year July 2016 to June 2017. Lists of degree recipients and subject classifications are provided by the university. Note: Dissertations without classifications may be found under 'Y Miscellaneous Categories.' [ABSTRACT FROM AUTHOR]