变更管理(Management of Change,MOC)在美国OSHA标准和我国工艺安全管理(PSM)体系中均被列为一个重要要素,但是由于我国管理起步较晚和缺乏经验等原因,导致MOC管理普遍存在问题。本文论述了变更管理的概念和起源,并以事故例证方式说明MO...变更管理(Management of Change,MOC)在美国OSHA标准和我国工艺安全管理(PSM)体系中均被列为一个重要要素,但是由于我国管理起步较晚和缺乏经验等原因,导致MOC管理普遍存在问题。本文论述了变更管理的概念和起源,并以事故例证方式说明MOC管理不当是造成国内外很多重大事故的原因,从而阐述了加强其管理的重要意义。以某石化企业借鉴国外先进管理经验并结合企业变更管理实际为例,重点论述变更实施过程管理、风险分析及分类审批方法,以及保障变更资料完整性和准确性3个方面问题的解决对策和方法尝试,供其它企业参考,共同降低整个社会的风险。展开更多
Global climate change has been found to substantially influence the phenology of rangeland,especially on the Tibetan Plateau. However, there is considerable controversy about the trends and causes of rangeland phenolo...Global climate change has been found to substantially influence the phenology of rangeland,especially on the Tibetan Plateau. However, there is considerable controversy about the trends and causes of rangeland phenology owing to different phenological exploration methods and lack of ground validation. Little is known about the uncertainty in the exploration accuracy of vegetation phenology.Therefore, in this study, we selected a typical alpine rangeland near Damxung national meteorological station as a case study on central Tibetan Plateau, and identified several important sources influencing phenology to better understand their effects on phenological exploration. We found man-made land use was not easily distinguished from natural rangelands, and therefore this may confound phenological response to climate change in the rangeland. Change trends of phenology explored by four methods were similar, but ratio threshold method(RTM) was more suitable for exploring vegetation phenology in terms of the beginning of growing season(BGS) and end of growing season(EGS). However, some adjustments are needed when RTM is used in extreme drought years. MODIS NDVI/EVI dataset was most suitable for exploring vegetation phenology of BGS and EGS. The discrimination capacities of vegetation phenology declined with decreasing resolution of remote sensing images from MODIS to GIMMS AVHRR datasets. Additionally, distinct trends of phenological change rates were indicated in different terrain conditions, with advance of growing season in high altitudes but delay of season in lower altitudes. Therefore, it was necessary to eliminate interference of complex terrain and man-made land use to ensure the representativeness of natural vegetation. Moreover, selecting the appropriate method to explore rangelands and fully considering the impact of topography are important to accurately analyze the effects of climate change on vegetation phenology.展开更多
文摘变更管理(Management of Change,MOC)在美国OSHA标准和我国工艺安全管理(PSM)体系中均被列为一个重要要素,但是由于我国管理起步较晚和缺乏经验等原因,导致MOC管理普遍存在问题。本文论述了变更管理的概念和起源,并以事故例证方式说明MOC管理不当是造成国内外很多重大事故的原因,从而阐述了加强其管理的重要意义。以某石化企业借鉴国外先进管理经验并结合企业变更管理实际为例,重点论述变更实施过程管理、风险分析及分类审批方法,以及保障变更资料完整性和准确性3个方面问题的解决对策和方法尝试,供其它企业参考,共同降低整个社会的风险。
基金supported by the National Natural Science Foundation of China (41271067)National key research and development program (2016YFC0502001)
文摘Global climate change has been found to substantially influence the phenology of rangeland,especially on the Tibetan Plateau. However, there is considerable controversy about the trends and causes of rangeland phenology owing to different phenological exploration methods and lack of ground validation. Little is known about the uncertainty in the exploration accuracy of vegetation phenology.Therefore, in this study, we selected a typical alpine rangeland near Damxung national meteorological station as a case study on central Tibetan Plateau, and identified several important sources influencing phenology to better understand their effects on phenological exploration. We found man-made land use was not easily distinguished from natural rangelands, and therefore this may confound phenological response to climate change in the rangeland. Change trends of phenology explored by four methods were similar, but ratio threshold method(RTM) was more suitable for exploring vegetation phenology in terms of the beginning of growing season(BGS) and end of growing season(EGS). However, some adjustments are needed when RTM is used in extreme drought years. MODIS NDVI/EVI dataset was most suitable for exploring vegetation phenology of BGS and EGS. The discrimination capacities of vegetation phenology declined with decreasing resolution of remote sensing images from MODIS to GIMMS AVHRR datasets. Additionally, distinct trends of phenological change rates were indicated in different terrain conditions, with advance of growing season in high altitudes but delay of season in lower altitudes. Therefore, it was necessary to eliminate interference of complex terrain and man-made land use to ensure the representativeness of natural vegetation. Moreover, selecting the appropriate method to explore rangelands and fully considering the impact of topography are important to accurately analyze the effects of climate change on vegetation phenology.
